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Die vorliegende Masterarbeit belegt, dass ein Innovationsvorhaben mittels „Bottom-up“-Management
zur Entwicklung einer gesamten Organisation führen kann. Dies wird exemplarisch an
der Curriculumentwicklung an einer Pflegeschule in Baden-Württemberg dargestellt. Hierfür
werden zunächst die Besonderheiten des „Bottom-up“-Managements herausgearbeitet und
anschließend unter Einbeziehung aller Rahmenbedingungen ein eigenes Handlungskonzept
für das Projektvorhaben erstellt. Das „Drei-Wege-Modell der Schulentwicklung“ von Rolff, welches
sich mit dem Zusammenhang zwischen der Unterrichtsentwicklung, der Personalentwicklung
und der Organisationsentwicklung befasst (vgl. Rolff 2016, S. 20), stellt in dieser
Arbeit neben der Qualitätssicherung einen wichtigen Orientierungsrahmen dar. Es wird zudem
gezeigt, dass sowohl das Führungsverhalten der Schulleitung als auch die Möglichkeit
zur partizipativen Mitarbeit aller Teilnehmenden der Schlüssel für das Gelingen des Innovationsvorhabens
ist. Damit die Ergebnisse dieser Arbeit auch gewinnbringend für andere Projektvorhaben
und Organisationen genutzt werden können, werden sie abschließend auf ihre
Übertragbarkeit hin geprüft. So können Teilaspekte diese Masterarbeit auch bei der Weiterentwicklung
weiterer Pflegeschulen oder anderer Organisationen eine Hilfe sein.
In Deutschland haben die Familienunternehmen eine lange Tradition. Einige weltberühmte deutsche Unternehmen, wie die Volkswagen AG, BMW Group oder Robert Bosch GmbH, werden von der Gründerfamilie oder deren Nachfolger geführt. Neben Familienunternehmen dieser Größenklasse werden auch viele andere mittelständige, familiengeführte Unternehmen in Deutschland jährlich an die nächste Generation weitergegeben oder vererbt. Ganz gleich ob bereits eine gezielte Nachfolgeplanung vorliegt oder ein plötzlicher Generationswechsel geschieht, soll das Firmenvermögen in aller Regel bei der Familie verbleiben.
Das Nachfolgemanagement gestaltet sich dabei oft schwierig, denn bei dem Thema Nachfolgeplanung müssen nicht nur die strategischen Ziele und die möglichen Akteure der Unternehmensfortführung gefunden werden, sondern es soll ebenfalls die Harmonie der Familie erhalten bleiben. In einigen Fällen ist kein Familienmitglied bereit dazu oder geeignet, das Unternehmen weiterzuführen. In solchen Fällen gibt es die Möglichkeit, die Fortführung in die Hände eines erfahrenen Managers zu legen. Für die Dauer der Fortführung wird i.d.R. eine Beteiligung am Firmenvermögen angeboten, um dem Manager eine intrinsische Motivation an der erfolgreichen Weiterführung des Familienunternehmens und an der Steigerung des Firmenvermögens, mithin auch seiner eigenen Beteiligung, zu geben.
Durch die Übertragung von Gesellschaftsanteilen wird der externe Manager Teil eines familiengeprägten Gesellschafterkreises. Es stellt sich die Frage, wie diese Übertragung so gestaltet werden kann, dass die Familie weiterhin die Kontrolle über die Anteile behält und nicht umgangen werden kann. Darüber hinaus stellt sich die Frage, wie weit solche Kontrollmaßnahmen ihre Reichweite erstrecken und wie sich die Auslegung solcher Klauseln ändern kann, wenn die Gesellschafter nicht mehr nur aus der Familie als homogene Einheit stammen und persönlich in der Gesellschaft nicht mehr mitarbeiten.
Bei der Entscheidung darüber, ob ein Kurzzitat ein Werk im Sinne des § 2 UrhG darstellt und damit urheberrechtlichen Schutz genießt, ziehen Gerichte oftmals ältere Entscheidungen heran. Die bereits in der Literatur aufgeworfene Frage, ob 30 oder gar 80 Jahre alte Urteile heute überhaupt noch – oder möglicherweise gerade heute wieder – herangezogen werden können und ob bei Kurzzitaten urheberrechtlicher Schutz nach der früheren Rechtslage schneller angenommen werden konnte als nach aktueller Rechtslage und insofern „früher tatsächlich mehr Lametta war“, wird im Rahmen dieser Masterarbeit aufgegriffen werden. Ebenso wird die Frage aufgeworfen, unter welchen Voraussetzungen Kurzzitate am Beispiel des Kurzzitates „Früher war mehr Lametta“ unter Berücksichtigung der Entwicklungen in der Rechtsprechung und der Literatur urheberrechtlich überhaupt schutzfähig sein können und wie sich dies, erläutert für verschiedene Erscheinungsformen, zukünftig in der Praxis auswirkt. Daneben wird aufgezeigt, wie die EU-Rechtsprechung Einfluss auf die deutsche Rechtsprechung genommen hat und welche Auswirkungen bezüglich der Schutzuntergrenze dies derzeit hat und zukünftig haben könnte. Auch, inwieweit Freihaltebedürfnisse in Deutschland und in Europa hierbei eine Rolle spielen, wird im Rahmen der Arbeit untersucht.
Das Kyoto-Protokoll, welches die letzten anderthalb Dekaden für Industrieländer erstmalig völkerrechtlich bindende Emissionsreduktionsziele für Treibhausgase festschrieb, läuft in diesem Jahr aus. Die im internationalen Abkommen entwickelten Klimaschutzin-strumente in Form eines Handels mit Emissionszertifikaten, sowie in Form von Emissi-onsreduktionen mittels Klimaschutzprojekten in Drittländern (Joint Implementation und Clean Development Mechanismus), konnten in der Vergangenheit nicht zum angestrebten Rückgang des weltweiten Treibhausgasausstoßes führen.
Das 2015 beschlossene Klimaabkommen von Paris soll die Regelungen des Kyoto-Protokolls nun ablösen und neue ambitionierte Standards im Klimaschutz setzen, um die Klimaerwärmung langfristig auf maximal 2 °C gegenüber des vorindustriellen Ni-veaus zu beschränken. Die grundlegend veränderten Rahmenbedingungen des Pariser Vertrags, sowie die Erfahrungen mit bisherigen flexiblen Instrumenten der Klimarah-menkonvention der Vereinten Nationen, erschweren aufgrund der hohen Komplexität und teils divergierender Interessenlagen der beteiligten Akteure seit 2015 sowohl die Entwicklung als auch die internationale Einigung auf einen neuen Marktmechanismus.
Die vorliegende Arbeit untersucht auf verschiedenen Ebenen, welche Vor- und Nachteile sich aus dem CDM ergeben haben und wie diese in die Ausgestaltung von Artikel 6 des Pariser Klimaschutzabkommens miteinfließen können. Dabei werden auch die Themen Klimakompensation und Klimaneutralität behandelt, welche zuletzt einen enormen Bedeutungszuwachs verzeichnen konnten und im Privatsektor inzwischen ein eminentes Nachfragepotential bergen. Im Zusammenhang mit den Attraktivitätsfaktoren einer Investition in Projekte, die nachhaltige Entwicklung fördern, werden hierzu auch die möglichen Hintergründe des verstärkten Engagements seitens der Unternehmen diskutiert.
Das theoretische Konzept der Arbeit basiert auf dem Free Rider Problem und den öko-logischen Managementregeln. Der Fokus liegt auf ökologischen Aspekten der Nachhaltigkeit, wobei ebenso ökonomische Komponenten ausschlaggebend sind.
Als ergänzendes Klimaschutzinstrument wird der Handel mit Emissionszertifikaten aufgegriffen, da er in der EU bereits etabliert ist.
Eine der größten Herausforderungen scheint es, wirtschaftliches Wachstum und Klimaschutz zu vereinen und Entwicklungsländern den Weg für eine Industrialisierung bzw. anziehende wirtschaftliche Entwicklung zu ebnen, welche keine nachholenden Ansprüche auf Emissionen stellt, sondern sich innovativ und inklusiv gestaltet. Für die Überwindung dieser derzeit bestehenden Kontroverse, die in engem Zu-sammenhang mit der Diskussion um einen neuen umfassenden Klimaschutzmechanismus steht, werden schließlich Empfehlungen ausgesprochen und ein abschließender Ausblick – auch unter Berücksichtigung der aktuellen Klimaschutzentwicklungen in Fol-ge der weltweiten COVID-19-Pandemie gewährt.
Gabriel Szulanski brachte im Jahr 1996 den Begriff „Sticky Knowledge“ in die Diskussion zum Wissenstransfer ein. Je ‚klebriger‘ Wissen ist, umso schwerer lässt es sich von einem Individuum zum anderen weitergeben. Dennoch erfährt die Wissens-Kommunikation sowohl in der Wissenschaft als auch in der Praxis zu geringe Aufmerksamkeit.
Oftmals wird sich auf die Wissensgewinnung und Akkumulation von Wissen fokussiert, ja sogar fixiert. Natürlich sind Gewinnung und Vermehrung von Wissen essenzielle Voraussetzungen, nur könnten diese fast bedeutungslos werden, wenn Wissen nicht in einen reibungslosen, und adressatenorientierten Fluss kommt. Ein herausforderndes, und am meisten unterschätztes Problem im Wissensmanagement ist, das Wissen an die Stellen zu bringen, wo es aktuell gebraucht wird (vgl. Probst et al., 2006).
Die Arbeit durchleuchtet ein bisher wenig erforschtes Teilgebiet des Wissensmanagements. Ursachen und (Aus)Wirkungen des Sticky Knowledge werden fundiert in ihrer jeweiligen Vielfältigkeit betrachtet. In Form von konkreten Handlungsempfehlungen für Organisationen und Individuen wird die Verbindung zwischen Theorie(n) und Praxis hergestellt. Zudem wird eine Begriffs-Definition des Sticky Knowledge hergeleitet.
#Sport #Gesundheit #Digital
(2021)
In ihrem 50. Jubiläumsjahr lud die Technische Universität Kaiserslautern am 26. und 27. November 2020 zu einem Höhepunkt ein: dem Kongress #Sport #Gesundheit #Digital. Für zwei Tage wurden im Rahmen eines Online-Forums gemeinsam die Themenfelder Sport, Gesundheit und Digitalisierung diskutiert. Wir freuen uns sehr, dass die Techniker Krankenkasse die TUK als Ausrichter der Veranstaltung besonders unterstützt hat. #SGD – Der Kongress setzte an der Schnittstelle von Sport, Gesundheit und Digitalisierung an und beleuchtete Chancen und Möglichkeiten, die durch das Zusammenspiel dieser Disziplinen entstehen können. Gleichzeitig wurden Risiken und Herausforderungen der digitalen Entwicklungen in Sport und Gesundheit betrachtet und perspektivisch mit Blick in die Zukunft analysiert. Hochkarätige Beiträge aus Wissenschaft und Praxis aus allen für das Themenspektrum relevanten Fachrichtungen sorgten für ein hohes Maß an Abwechslung und Transfer. Der Kongress richtete sich dabei nicht nur an Personen aus Wissenschaft und Praxis der Bereiche Gesundheitswesen und -management, Medizin und Psychologie. Ebenso angesprochen wurden Übungsleitende und Angehörige aus Hochschulsport und Sportwissenschaft, Studierende und Mitarbeitende aller bezogenen Fachrichtungen sowie alle allgemein interessierten Personen. Der vorliegende Kongressband stellt die Sammlung der Kongressinhalte dar. Neben den schriftlichen Beiträgen lassen sich hier auch Impressionen der Kongresstage und die Vorträge als interaktiv eingebundene Videos finden.
Der Sammelband „(Selbst-)Lernkompetenzen Studierender stärken: Unterstützungsangebote – Beratung – Lernräume“ enthält Beiträge von Akteur:innen an deutschen und österreichischen Hochschulen, die auf der Online-Fachtagung „(Selbst-)Lernunterstützung an Hochschulen – wieso noch mal?“ im Oktober 2020 an der Technischen Universität Kaiserslautern (seit 1.1.2023 Rheinland-Pfälzische Technische Universität Kaiserslautern-Landau) vorgestellt und diskutiert wurden. Ausgerichtet wurde die Tagung vom Projekt „Selbstlernförderung als Grundlage“ (Website: https://www.uni-kl.de/slzprojekt/).
Der Sammelband enthält 26 Beiträge und 18 Poster zu diesen thematischen Schwerpunkten:
I. Übergreifende Überlegungen zur zukunftsfähigen Hochschule
II. (Selbst-)Lernräume – physisch und virtuell
III. Angebote zur Unterstützung von (Selbst-)Lernkompetenzen – fachbezogen oder fächerübergreifend
IV. Beratung – individuell und institutionell.
Didaktische Formate und Unterstützungsstrukturen an deutschen Hochschulen haben sich in den letzten zwei Jahrzehnten vor dem Hintergrund veränderter gesellschaftlicher Bedarfe, neuer Zielgruppen, didaktischer Impulse und politischer Rahmenbedingungen gewandelt. Auf der Fachtagung ebenso wie im vorliegenden Sammelband präsentieren Vertreter:innen unterschiedlicher Hochschulstandorte ihre theoretischen, empirischen und praktischen Erkenntnisse im Hinblick auf Angebotsgestaltung, Wirksamkeit und Akzeptanz von Maßnahmen zur Stärkung der (Selbst-)Lernkompetenzen Studierender.
Die Beiträge geben einen Einblick in die Konzeption und Durchführung von überfachlichen Unterstützungs- und Beratungsangeboten und in die Gestaltung physischer und virtueller Lernräume für Studierende. So werden vielfältige Good Practices vorgestellt, kritisch diskutiert und hinsichtlich der Tragfähigkeit für die Hochschule der Zukunft reflektiert. Hierbei fließen insbesondere die Erfahrungen ein, die im Zuge der Covid-19-Pandemie und der (zeitweisen) Umstellung in den Online- und -Hybrid-Modus an den Hochschulen gemacht wurden. In ihre Ausarbeitung der Beiträge für den vorliegenden Sammelband haben die Autor:innen die neueren Erfahrungswerte aus dem Zeitraum Sommersemester 2020 bis Wintersemester 2021/22 eingearbeitet. Das Zukunftspotenzial der Angebote für Studierende in der Zeit während der Pandemie und in der Zeit des Pandemie-Nachklangs im „New Normal“-Betrieb wird somit kritisch beleuchtet. Dies wird gerahmt durch übergreifende, pädagogische und hochschulstrategische Betrachtungen zum Thema „zukunftsfähige Hochschule“.
Der Sammelband wird herausgegeben von Monika Haberer (Geschäftsführerin des Zentrums für Innovation und Digitalisierung in Studium und Lehre, ZIDiS), Dr. Dorit Günther und Janina Köhler (wissenschaftliche Mitarbeiterinnen des ZIDiS). Website: zidis.rptu.de/
Wissenschaftliche Evidenz zum Thema "(Un-)Wirksamkeit von Strafe" wird in der Öffentlichkeit kontrovers diskutiert. In der vorliegenden Arbeit wird vermutet, dass es bei der Rezeption zu motivierten Verzerrungen, genauer gesagt, zu einer Bedrohung der moralischen Wertvorstellungen kommt, infolgedessen wissenschaftliche Erkenntnisse diskreditiert und abgelehnt werden. Hierfür wurde zunächst die moralische Begründung von persönlichen Strafeinstellungen systematisch untersucht. Dabei zeigte sich, dass eine deliktspezifische (nach Kriminalitätsbereichen aufgeteilte) Betrachtung erforderlich ist. Regressionsanalysen konnten die qualitativen Unterschiede hinsichtlich der zugrundeliegenden Wertvorstellungen belegen. Die Art und Weise der Operationalisierung erwies sich hierbei als entscheidend für den "moralischen Gehalt" der individuellen Strafeinstellung.
Eine Bedrohung moralischer Wertvorstellungen durch einen wissenschaftlichen Artikel, der sich gegen die Wirksamkeit von harten Strafen (deliktspezifisch) ausspricht, konnte nicht nachgewiesen werden. Weitere Moderationsanalysen offenbarten jedoch unabhängig von den persönlichen Wertvorstellungen eine motivierte Verzerrung bei der Rezeption des Artikels: TeilnehmerInnen, die an die Wirksamkeit von Strafe glaubten, bewerteten einen Artikel, der dies widerlegte, schlechter als diejenigen, die einen Artikel lasen, der dies bestätigte. Diese Verzerrungen liegen jedoch nicht in einer moralischen Bedrohung begründet, sondern lassen sich vielmehr als Strategie zur Auflösung von Dissonanz bei Konfrontation mit einstellungsinkonsistenten Inhalten verstehen. Kern des Problems sind offenbar nicht die untersuchten persönlichen Wertvorstellungen und deren Bedrohung, sondern das hohe Ausmaß der Diskrepanz zwischen öffentlicher und wissenschaftlicher Meinung. Diese Erkenntnis ist insofern von Bedeutung, als dass sie ein Bewusstsein für die Gefahren (z.B. eines Bumerang-Effekts) bei der Kommunikation der Inhalte schafft.
Insgesamt betrachtet tragen die Ergebnisse zu einem tieferen Verständnis persönlicher Strafeinstellungen bei und liefern Ansatzpunkte für die Entwicklung von Strategien zur überzeugenden Kommunikation kriminologischer Erkenntnisse bezüglich der Sinnhaftigkeit von Strafe.
III/V semiconductor quantum dots (QD) are in the focus of optoelectronics research for about 25 years now. Most of the work
has been done on InAs QD on GaAs substrate. But, e.g., Ga(As)Sb (antimonide) QD on GaAs substrate/buffer have also gained
attention for the last 12 years.There is a scientific dispute on whether there is a wetting layer before antimonide QD formation, as
commonly expected for Stransky-Krastanov growth, or not. Usually ex situ photoluminescence (PL) and atomic force microscope
(AFM) measurements are performed to resolve similar issues. In this contribution, we show that reflectance anisotropy/difference
spectroscopy (RAS/RDS) can be used for the same purpose as an in situ, real-time monitoring technique. It can be employed not
only to identify QD growth via a distinct RAS spectrum, but also to get information on the existence of a wetting layer and its
thickness. The data suggest that for antimonide QD growth the wetting layer has a thickness of 1 ML (one monolayer) only.
Riesling wird neben seiner mannigfaltigen Variabilität im Aromaprofil, das unter anderem durch die unterschiedliche Bodenbeschaffenheit entsteht, vor allem in Deutschland auch wegen seiner Kältetoleranz und Anpassungsfähigkeit geschätzt. Er gilt zudem auch als alterungsfähiger Wein, allerdings kommt es bei zu starker Sonnenexposition der Rebe und langer bzw. warmer Lagerung vermehrt zur Bildung von 1,1,6-Trimethyl-1,2-dihydronaphthalin (TDN). Dieser von Carotinoiden abstammende Aromastoff verursacht die sogenannte „Petrolnote“, die vor allem in wärmeren Anbauregionen zum sortentypischen Bukett des Rieslings gehört. Deutsche Rieslingweine zeichnen sich dagegen überwiegend durch einen säurebetonten, fruchtigen Charakter aus, bei dem das Auftreten einer Petrolnote vor allem im Fall von Jungweinen als unpassende Fehlnote empfunden wird.
Das Ziel der vorliegenden Arbeit war deswegen, die sensorische Relevanz von TDN zu evaluieren und Maßnahmen zu realisieren, die geeignet sind, die Konzentrationen an freiem und gebundenem TDN zu verringern und dadurch das Auftreten der Petrolnote zu vermeiden.
Dafür wurde zunächst in Kapitel 6.1 die Empfindlichkeit von Verbrauchern und geschulten Prüfern gegenüber TDN sowie die Konzentration bestimmt, ab der die Petrolnote zu einer Ablehnung des Weins durch Verbraucher führt. Während geschulte Prüfer Rieslingweine bereits ab einem TDN-Gehalt von 2,3 µg/L unterscheiden konnten, lag die Wahrnehmungsschwelle von 156 Verbrauchern mit 14,7 µg/L um ein Mehrfaches darüber, und wurde außerdem durch das Geschlecht der Probanden beeinflusst. Die Petrolnote führte ab TDN-Gehalten von 60 µg/L bei einjährigem und 91 µg/L bei achtjährigem Riesling zur Ablehnung des Weins. Die Konzentration an freiem TDN in 261 Rieslingweinen aus drei verschiedenen Weinwettbewerben überstieg bei rund der Hälfte der Weine die Wahrnehmungsschwelle von geschulten Prüfern, während die Wahrnehmungsschwelle von Verbrauchern nur von 15% der Weine überschritten wurde. Gleichzeitig lag bei keinem der Weine der TDN-Gehalt über der Ablehnungsschwelle.
Durch die Evaluierung der instrumentellen Analyseparameter in Kapitel 6.2 wurde für die Untersuchung von freiem TDN und weiteren Aromastoffen eine Methode entwickelt, die es ermöglicht, nicht nur die TDN-Konzentrationen zu erfassen, sondern auch eine umfassende Qualitätsbewertung der Versuchsweine durchzuführen. Parallel dazu wurde eine Schnellmethode zur Erfassung der Gehalte an gebundenem TDN und Vitispiran implementiert, um auch die Effektivität der in dieser Arbeit durchgeführten weinbaulichen und oenologischen Praktiken im Hinblick auf das TDN-Potential zu beurteilen.
Kapitel 6.3 und 6.4 beschreiben weinbauliche Maßnahmen, die in mehrjährigen Studien auf ihre Eignung zur Reduzierung der TDN-Konzentration untersucht wurden. Während bei den Weinen, die aus Beeren unterschiedlicher Größe hergestellt wurden, keine signifikanten Unterschiede über die Jahrgänge hinweg beobachtet wurden, konnte durch die Variation der Rebunterlagen der Gehalt an gebundenem TDN um rund 30% reduziert werden. Ausgangspunkt einer weiteren Versuchsreihe waren acht verschiedene Rieslingklone auf derselben Unterlage, welche anschließend auf ihren TDN Gehalt untersucht wurden. Dabei wurden deutliche Differenzen in der Disposition einiger Klone zu höheren Gehalten an gebundenem TDN festgestellt. Hier ergab sich eine positive Korrelation zwischen der Lockerbeerigkeit der Trauben und der Menge an gebundenem TDN in den produzierten Weinen – je kompakter die Traube, desto weniger gebundenes TDN und gebundenes Vitispiran wurde gebildet. Die höhere Sonnenexposition der Beeren, die diesen Effekt hervorruft, beeinflusste auch die Gehalte an gebundenem TDN und Vitispiran in Weinen, die von Reben geerntet wurden, welche zu unterschiedlichen Zeitpunkten und in variierender Intensität entblättert wurden. Dabei führt sowohl eine maximale Entblätterung in der Traubenzone wie auch die Laubentfernung einen Monat nach der Blüte zu einer Erhöhung der Konzentration an gebundenem TDN und Vitispiran von rund 50%. Entblätterungsmaßnahmen zur Blüte oder zur Véraison, die der Regulierung der Erntemenge und der Traubengesundheit dienen, führten dagegen zu keinem Anstieg im Vergleich zur nicht-entblätterten Kontrolle.
Wie in Kapitel 6.5 ausgeführt wird, resultiert ein hoher Pressdruck beim Keltern sowie ein niedriger Stickstoffgehalt des Mosts in einer Zunahme des gebundenen TDN von 50 100%. Höhere Säuregehalte während der Lagerung verursachten in mehreren Versuchsreihen nicht nur eine höhere Freisetzungsrate von TDN, sondern auch einen verstärkten Abbau anderer Aromastoffe wie Ester, β-Damascenon oder Linalool. Dagegen hatte ein niedriger pH-Wert während der Gärung kaum Einfluss auf den Hefemetabolismus und die dadurch gebildeten Aromastoffe. Die Erhöhung der Gärtemperatur von 12 auf 24 °C hatte jedoch eine Zunahme von honig- oder petrolartigen Noten in den Rieslingweinen zur Folge. Die Verwendung unterschiedlicher Hefestämme führte zu einer Variation der Konzentrationen an gebundenem TDN zwischen 70 und 147 µg/L, abhängig vom Hefestamm und dem Jahrgang. Zwei der untersuchten neun Hefen brachten Weine mit bis zu 40% geringeren Gehalten an gebundenem TDN in Mosten mit hohem Stickstoffgehalt hervor, während drei weitere Hefen besser für den Einsatz in nährstoffarmen Most geeignet waren. Bei der Lagerung der Weine spielte die Lagertemperatur eine entscheidende Rolle in Bezug auf den Gehalt an freiem TDN, gefolgt vom Material des Flaschenverschlusses und der Flaschenorientierung.
Mittels geeigneter Filtermaterialien, die in Kapitel 7 beschrieben sind, wurde der Gehalt an freiem Wein um bis zu 80% reduziert, ohne die meisten der anderen Aromastoffe signifikant zu beeinflussen.
Somit wurde durch diese Arbeit ein vielfältiger Maßnahmenkatalog für die Weinwirtschaft entwickelt, der geeignet ist, den Anforderungen des fortschreitenden Klimawandels entgegenzutreten und die herausragende Position des Rieslings in Deutschland zu sichern.
Der direkte Einstieg in die Phosphorchemie ist durch Reaktion einer Rohlösung von [Cp=Ru(CO)2H] (1) (Cp= = C5H3(SiMe3)2) mit P4 möglich. Dabei erhält man den Komplex [Cp=Ru(CO)2PH2] (6a) mit freier Phosphanidogruppe, der selbst nicht isoliert, dessen Existenz jedoch spektroskopisch und durch Folgereaktionen eindeutig belegt werden kann. Das freie Elektronenpaar des Phosphors kann sowohl durch [M(CO)5(thf)] (M = Cr, Mo, W) (7,8,9) als auch durch [Cp*Re(CO)2(thf)] (14) nach Verlust von deren thf-Liganden komplexiert werden. Das bei der Reaktion mit 14 als Nebenprodukt entstandene [{Cp*(OC)2Re}2(µ-CO)] (17) konnte erstmals röntgenstrukturanalytisch untersucht werden. Die Cothermolyse von [{Cp=Ru(CO)2}2] (4) mit P4 liefert [Cp=Ru(Eta5-P5)] (18) und [{Cp=Ru}2(µ-Eta;2:2-P2)2] (19), die beide röntgenstrukturanalytisch charakterisiert werden konnten. 18 erweist sich als erstes Pentaphosphametallocen, das eine annähernd ideal ekliptische Konformation aufweist. Im Zweikernkomplex 19 konnte ein Komplex der 8. Gruppe mit zwei separaten P2-Brückenliganden eindeutig belegt werden. Die Cothermolyse von 4 mit [Cp*Fe(Eta5-P5)] liefert neben 18 und 19 die Homo- und Heterotrimetallcluster [{Cp=Ru}n{Cp*Fe}3-nP5] (n = 1, 2, 3) mit verzerrt dreiecksdodekaedrischen Gerüststrukturen. Die Röntgenstrukturanalysen von [{Cp=Ru}3P5] (24), [{Cp=Ru}2{Cp*Fe}P5] (25) und [{Cp*Fe}2{Cp=Ru}P5] (26) zeigen, daß die Metallfragmente {Cp*Fe} und {Cp=Ru} nahezu ohne Auswirkungen auf die Gerüststruktur ausgetauscht werden können. Der Vergleich zu den Cp-Derivaten zeigt die annähernde Identität der Verbindungen. Bei 26 bleibt die Stellung des Cp=-Liganden am Ruthenium nach Einbau eines Eisenfragmentes erhalten, während in [{Cp*Fe}2{CpRu}P5] (26a) ein Wechsel in der Stellung des Cp-Liganden stattfindet. Die Photolyse von [Cp=Ru(CO)2H] (1) in THF ergibt die spektroskopisch identifizierten Verbindungen [{Cp=Ru(CO)}2(µ-H)2] (28), [{Cp=Ru(CO)}2{Cp=Ru(CO)H}] (29) und [{Cp=Ru}4(µ3-CO)4] (30). Das in geringen Mengen anfallende 28 konnte als dimere Struktur mit zwei verbrückenden Wasserstoffatomen identifiziert werden. Für Komplex 29 wurde eine Struktur als triangularer Metalldreiring postuliert, der den Verbindungen 33 und 34 sehr ähnlich ist. Bei 29 handelt es sich um einen 46 VE-Komplex mit einer Ru-Ru-Doppelbindung im Dreiring. Verbindung 30 mit tetraedrischem Ru4-Gerüst kann in hoher Ausbeute dargestellt werden. 30 ist luft- und wasserstabil und überaus reaktionsträge. Führt man die Photolyse von 1 in Hexan als nichtkoordinierendem Lösungsmittel durch, so erhält man neben 28 und 29 die Komplexe [{Cp=Ru(µ-CO)}2{Cp=Ru(CO)H}] (33), [{{{Cp=Ru}2(µ-CO)}{Cp=RuH}}(µ3-CO)2] (34) sowie die unbekannte Verbindung 35. Die Röntgenstrukturanalysen von 33 und 34 zeigen zwei mit 46 VE elektronendefiziente, triangulare Ru3-Cluster mit einer M-M-Doppelbindung im Ring, welche beide der Vorgabe der Magischen Zahlen entsprechen. 33 reagiert bereitwillig mit P4 und ergibt [{Cp=Ru}(µ-Eta4:1:1-P4){Ru(CO)Cp=}] (40). Die RSA von 40 zeigt, daß Ru1 um 25,3° aus der Ebene der vier Phosphoratome P1-P4 abgewinkelt und kein planares Tetraphospharuthenol verwirklicht ist. Die Aufsicht auf die P4Ru-Ebene läßt jedoch deutlich das Bestreben erkennen, die Konstitution einer pentagonalen Pyramide auszubilden.
Modern society relies on convenience services and mobile communication. Cloud computing is the current trend to make data and applications available at any time on every device. Data centers concentrate computation and storage at central locations, while they claim themselves green due to their optimized maintenance and increased energy efficiency. The key enabler for this evolution is the microelectronics industry. The trend to power efficient mobile devices has forced this industry to change its design dogma to: ”keep data locally and reduce data communication whenever possible”. Therefore we ask: is cloud computing repeating the aberrations of its enabling industry?
The plasma membrane transporter SOS1 (SALT-OVERLY SENSITIVE1) is vital for plant survival under salt stress. SOS1 activity is tightly regulated, but little is known about the underlying mechanism. SOS1 contains a cytosolic, autoinhibitory C-terminal tail (abbreviated as SOS1 C-term), which is targeted by the protein kinase SOS2 to trigger its transport activity. Here, to identify additional binding proteins that regulate SOS1 activity, we synthesized the SOS1 C-term domain and used it as bait to probe Arabidopsis thaliana cell extracts. Several 14-3-3 proteins, which function in plant salt tolerance, specifically bound to and interacted with the SOS1 C-term. Compared to wild-type plants, when exposed to salt stress, Arabidopsis plants overexpressing SOS1 C-term showed improved salt tolerance, significantly reduced Na+ accumulation in leaves, reduced induction of the salt-responsive gene WRKY25, decreased soluble sugar, starch, and proline levels, less impaired inflorescence formation and increased biomass. It appears that overexpressing SOS1 C-term leads to the sequestration of inhibitory 14-3-3 proteins, allowing SOS1 to be more readily activated and leading to increased salt tolerance. We propose that the SOS1 C-term binds to previously unknown proteins such as 14-3-3 isoforms, thereby regulating salt tolerance. This finding uncovers another regulatory layer of the plant salt tolerance program
In der vorliegenden Masterarbeit wurden Machbarkeit und Vorteile von verschiedenen Aufnahmezeitintervallen, sowie einer quantitativen Analyse von Blutflusswerten für Aktivierungsstudien des auditorischen Systems bei einer kleinen Zahl von CI-Nutzern mit unterschiedlicher Hörperformance/zu erwartender Aktivierung evaluiert. Dafür wurden die PET-Daten sogenannter „good performer“ und „poor performer“ zunächst individuell analysiert. Die Beurteilung der Performance erfolgte über das Sprachverstehen im Störgeräusch (HSM-Satztest), bei dem die Probanden entweder ≥ 70 % oder ≤ 30 % verstehen [13]. Eine Unterscheidung bzw. Auswertung zwischen den Gruppen findet in der vorliegenden Masterarbeit nicht statt. Um den Ergebnissen jedoch eine breitere Gültigkeit zu geben, ist es von Vorteil, ein Spektrum unterschiedlicher CI-Nutzer mit unterschiedlicher Hörperfor-mance zu inkludieren.
Die Analyse des Aufnahmezeitintervalls wurde mittels Statistical Parametric Mapping (SPM) durchgeführt, die Blutflussquantifizierung mittels PMOD Software. Die mit diesen Verfahren individuell ermittelten Werte wurden anschließend weiter statistisch analysiert.
Previously in this journal we have reported on fundamental transversemode selection (TMS#0) of broad area semiconductor lasers
(BALs) with integrated twice-retracted 4f set-up and film-waveguide lens as the Fourier-transform element. Now we choose and
report on a simpler approach for BAL-TMS#0, i.e., the use of a stable confocal longitudinal BAL resonator of length L with a
transverse constriction.The absolute value of the radius R of curvature of both mirror-facets convex in one dimension (1D) is R = L
= 2f with focal length f.The round trip length 2L = 4f againmakes up for a Fourier-optical 4f set-up and the constriction resulting
in a resonator-internal beam waist stands for a Fourier-optical low-pass spatial frequency filter. Good TMS#0 is achieved, as long
as the constriction is tight enough, but filamentation is not completely suppressed.
1. Introduction
Broad area (semiconductor diode) lasers (BALs) are intended
to emit high optical output powers (where “high” is relative
and depending on the material system). As compared to
conventional narrow stripe lasers, the higher power is distributed
over a larger transverse cross-section, thus avoiding
catastrophic optical mirror damage (COMD). Typical BALs
have emitter widths of around 100 ????m.
Thedrawback is the distribution of the high output power
over a large number of transverse modes (in cases without
countermeasures) limiting the portion of the light power in
the fundamental transverse mode (mode #0), which ought to
be maximized for the sake of good light focusability.
Thus techniques have to be used to support, prefer, or
select the fundamental transverse mode (transverse mode
selection TMS#0) by suppression of higher order modes
already upon build-up of the laser oscillation.
In many cases reported in the literature, either a BAL
facet, the
2D quantum dilaton gravitational Hamiltonian, boundary terms and new definition for total energy
(1995)
The ADM and Bondi mass for the RST model have been first discussed from Hawking and Horowitz's argument. Since there is a nonlocal term in the RST model, the RST lagrangian has to be localized so that Hawking and Horowitz's proposal can be carried out. Expressing the localized RST action in terms of the ADM formulation, the RST Hamiltonian can be derived, meanwhile keeping track of all boundary terms. Then the total boundary terms can be taken as the total energy for the RST model. Our result shows that the previous expression for the ADM and Bondi mass actually needs to be modified at quantum level, but at classical level, our mass formula can be reduced to that given by Bilal and Kogan [5] and de Alwis [6]. It has been found that there is a new contribution to the ADM and Bondi mass from the RST boundary due to the existence of the hidden dynamical field. The ADM and Bondi mass with and without the RST boundary for the static and dynamical solutions have been discussed respectively in detail, and some new properties have been found. The thunderpop of the RST model has also been encountered in our new Bondi mass formula.
30 Jahre sind seit Aufnahme der Bibliotheksarbeit an der Universität Kaiserslautern vergangen. Galt es in den ersten Jahren den Literaturversorgungsauftrag für die ersten Fächer der 1970 gegründeten Universität zu erfüllen und eine dafür brauchbare Bibliotheksstruktur zu finden, so wurde die Arbeit in den letzten Jahren durch die tiefgreifende Entwicklung im Informations- und Kommunikationsbereich nachhaltig geprägt. Der technologische Wandel bei Mikroelektronik und Software-Entwicklung beeinflusst die bibliothekarische Arbeit ebenso wie die elektronischen Medien selbst und die stärkere Einbindung in Informations- und Versorgungsnetze die Benutzungsdienstleistungen der Bibliotheken umgestalten. Umstrukturierungsprozesse auf der Anbieterseite verlangen schnelles Reagieren der Bibliotheken auf der Abnehmer- und Vermittlerseite und den zügigen Auf- und Ausbau der lokal erforderlichen Infrastruktur. Der Rückblick auf die Aufbau- und Entwicklungsphase der Universitätsbibliothek Kaiserslautern soll im Rahmen der eit 1972 jährlich erscheinenden Geschäftsberichte (Bericht über das Geschäftsjahr ...) zusammenfassend erfolgen, wobei keine alles umfassende Darstellung beabsichtigt ist, sondern dem Muster früherer Berichte folgend nur partielle Rückblicke gegeben werden. Es sollte keine Festschrift, die oft aus solchen Anlässen erstellt wird, entstehen.
This paper considers the numerical solution of a transmission boundary-value problem for the time-harmonic Maxwell equations with the help of a special finite volume discretization. Applying this technique to several three-dimensional test problems, we obtain large, sparse, complex linear systems, which are solved by using BiCG, CGS, BiCGSTAB resp., GMRES. We combine these methods with suitably chosen preconditioning matrices and compare the speed of convergence.
Destructive diseases of the lung like lung cancer or fibrosis are still often lethal. Also in case of fibrosis in the liver, the only possible cure is transplantation.
In this thesis, we investigate 3D micro computed synchrotron radiation (SR\( \mu \)CT) images of capillary blood vessels in mouse lungs and livers. The specimen show so-called compensatory lung growth as well as different states of pulmonary and hepatic fibrosis.
During compensatory lung growth, after resecting part of the lung, the remaining part compensates for this loss by extending into the empty space. This process is accompanied by an active vessel growing.
In general, the human lung can not compensate for such a loss. Thus, understanding this process in mice is important to improve treatment options in case of diseases like lung cancer.
In case of fibrosis, the formation of scars within the organ's tissue forces the capillary vessels to grow to ensure blood supply.
Thus, the process of fibrosis as well as compensatory lung growth can be accessed by considering the capillary architecture.
As preparation of 2D microscopic images is faster, easier, and cheaper compared to SR\( \mu \)CT images, they currently form the basis of medical investigation. Yet, characteristics like direction and shape of objects can only properly be analyzed using 3D imaging techniques. Hence, analyzing SR\( \mu \)CT data provides valuable additional information.
For the fibrotic specimen, we apply image analysis methods well-known from material science. We measure the vessel diameter using the granulometry distribution function and describe the inter-vessel distance by the spherical contact distribution. Moreover, we estimate the directional distribution of the capillary structure. All features turn out to be useful to characterize fibrosis based on the deformation of capillary vessels.
It is already known that the most efficient mechanism of vessel growing forms small torus-shaped holes within the capillary structure, so-called intussusceptive pillars. Analyzing their location and number strongly contributes to the characterization of vessel growing. Hence, for all three applications, this is of great interest. This thesis provides the first algorithm to detect intussusceptive pillars in SR\( \mu \)CT images. After segmentation of raw image data, our algorithm works automatically and allows for a quantitative evaluation of a large amount of data.
The analysis of SR\( \mu \)CT data using our pillar algorithm as well as the granulometry, spherical contact distribution, and directional analysis extends the current state-of-the-art in medical studies. Although it is not possible to replace certain 3D features by 2D features without losing information, our results could be used to examine 2D features approximating the 3D findings reasonably well.
Vorgestellt wird ein System basierend auf einem 3D-Scanner nach dem Licht- schnitt-Prinzip mit dem es möglich ist, einen Menschen innerhalb von 1,5 Sekun- den dreidimensional zu erfassen. Mit Hilfe von Evolutionären Algorithmen wird über eine modellbasierte Dateninterpretation die Auswertung der Meßdaten betrie- ben, so daß beliebige Körpermaße ermittelt werden können. Das Ergebnis ist ein individualisiertes CAD-Modells der Person im Rechner. Ein derartiges Modell kann als virtuelle Kleiderpuppe zur Produktion von Maßbekleidung dienen.
The various uses of fiber-reinforced composites, for example in the enclosures of planes, boats and cars, generates the demand for a detailed analysis of these materials. The final goal is to optimize fibrous materials by the means of “virtual material design”. New fibrous materials are virtually created as realizations of a stochastic model and evaluated with physical simulations. In that way, materials can be optimized for specific use cases, without constructing expensive prototypes or performing mechanical experiments. In order to design a practically fabricable material, the stochastic model is first adapted to an existing material and then slightly modified. The virtual reconstruction of the existing material requires a precise knowledge of the geometry of its microstructure. The first part of this thesis describes a fiber quantification method by the means of local measurements of the fiber radius and orientation. The combination of a sparse chord length transform and inertia moments leads to an efficient and precise new algorithm. It outperforms existing approaches with the possibility to treat different fiber radii within one sample, with high precision in continuous space and comparably fast computing time. This local quantification method can be directly applied on gray value images by adapting the directional distance transforms on gray values. In this work, several approaches of this kind are developed and evaluated. Further characterization of the fiber system requires a segmentation of each single fiber. Using basic morphological operators with specific structuring elements, it is possible to derive a probability for each pixel describing if the pixel belongs to a fiber core in a region without overlapping fibers. Tracking high probabilities leads to a partly reconstruction of the fiber cores in non crossing regions. These core parts are then reconnected over critical regions, if they fulfill certain conditions ensuring the affiliation to the same fiber. In the second part of this work, we develop a new stochastic model for dense systems of non overlapping fibers with a controllable level of bending. Existing approaches in the literature have at least one weakness in either achieving high volume fractions, producing non overlapping fibers, or controlling the bending or the orientation distribution. This gap can be bridged by our stochastic model, which operates in two steps. Firstly, a random walk with the multivariate von Mises-Fisher orientation distribution defines bent fibers. Secondly, a force-biased packing approach arranges them in a non overlapping configuration. Furthermore, we provide the estimation of all parameters needed for the fitting of this model to a real microstructure. Finally, we simulate the macroscopic behavior of different microstructures to derive their mechanical and thermal properties. This part is mostly supported by existing software and serves as a summary of physical simulation applied to random fiber systems. The application on a glass fiber reinforced polymer proves the quality of the reconstruction by our stochastic model, as the effective properties match for both the real microstructure and the realizations of the fitted model. This thesis includes all steps to successfully perform virtual material design on various data sets. With novel and efficient algorithms it contributes to the science of analysis and modeling of fiber reinforced materials.
We compute three-dimensional displacement vector fields to estimate the deformation of microstructural data sets in mechanical tests. For this, we extend the well-known optical flow by Brox et al. to three dimensions, with special focus on the discretization of nonlinear terms. We evaluate our method first by synthetically deforming foams and comparing against this ground truth and second with data sets of samples that underwent real mechanical tests. Our results are compared to those from state-of-the-art algorithms in materials science and medical image registration. By a thorough evaluation, we show that our proposed method is able to resolve the displacement best among all chosen comparison methods.
In this contribution a phase field model for ductile fracture with linear isotropic hardening is presented. An energy functional consisting of an elastic energy, a plastic dissipation potential and a Griffith type fracture energy constitutes the model. The application of an unaltered radial return algorithm on element level is possible due to the choice of an appropriate coupling between the nodal degrees of freedom, namely the displacement and the crack/fracture fields. The degradation function models the mentioned coupling by reducing the stiffness of the material and the plastic contribution of the energy density in broken material. Furthermore, to solve the global system of differential equations comprising the balance of linear momentum and the quasi-static Ginzburg-Landau type evolution equation, the application of a monolithic iterative solution scheme becomes feasible. The compact model is used to perform 3D simulations of fracture in tension. The computed plastic zones are compared to the dog-bone model that is used to derive validity criteria for KIC measurements.
The fifth-generation (5G) of wireless networks promises to bring new advances, such as a huge increase in mobile data rates, a plunge in communications latency, and an increase in the quality of experience perceived by users that can cope with the ever-increasing demand in Internet traffic. However, the high cost of capital and operational expenditure (CAPEX/OPEX) of the new 5G network and the lack of a killer application hinder its rapid adoption. In this context, Mobile Network Operators (MNOs) have turned their attention to the following idea: opening up their infrastructure so that vertical businesses can leverage the new 5G network to improve their primary businesses and develop new ones. However, deploying multiple isolated vertical applications on top of the same infrastructure poses unique challenges that must be addressed. In this thesis, we provide critical contributions to developing 5G networks to accommodate different vertical applications in an isolated, flexible, and automated manner. This thesis contributions spawn on three main areas: (i) the development of an integrated fronthaul and backhaul network, (ii) the development of a network slicing overbooking algorithm, and (iii) the development of a method to mitigate the noisy neighbors' problem in a vRAN deployment.
Sensing location information in indoor scenes requires a high accuracy and is a challenging task, mainly because of multipath and NLoS (non-line-of-sight) propagation. GNSS signals cannot penetrate well in indoor environment. Satellite-based navigation and positioning systems cannot therefore be used for indoor positioning.. Other technologies have been suggested for indoor usage, among them, Wi-Fi (802.11) and 5G NR (New Radio). The primary aim of this study is to discuss the advantages and drawbacks of 5G and Wi-Fi positioning techniques for indoor localization.
This paper presents a new approach to parallel path planning for industrial robot arms with six degrees of freedom in an on-line given 3D environment. The method is based a best-first search algorithm and needs no essential off-line computations. The algorithm works in an implicitly discrete configuration space. Collisions are detected in the Cartesian workspace by hierarchical distance computation based on polyhedral models of the robot and the obstacles. By decomposing the 6D configuration space into hypercubes and cyclically mapping them onto multiple processing units, a good load distribution can be achieved. We have implemented the parallel path planner on a workstation cluster with 9 PCs and tested the planner for several benchmark environments. With optimal discretisation, the new approach usually shows very good speedups. In on-line provided environments with static obstacles, the parallel planning times are only a few seconds.
Photolysiert man [{Cp R Ru(CO)2}2] (Cp R = Cp", Cp*) (1a,b), in Gegenwart von weißem Phosphor, so können keine phosphorhaltigen Produkte isoliert werden. Setzt man [{Cp"Ru(CO)2}2] (1a) mit weißem Phosphor bei 190 °C in Dekalin um, dann lassen sich als einzige Verbindungen das Pentaphospharuthenocen-Derivat [Cp"Ru(h 5 -P5)] (3a, 6 % Ausbeute) und [Cp"2Ru2P4] (4a, 17 % Ausbeute) säulenchromatographisch abtrennen. Für 4a wird auf Grund seiner spektroskopischen Eigenschaften eine den röntgenstruktur-analytisch charakterisierten pseudo-Tripeldecker-Komplexen [{Cp R Fe}2(micro-h 4:4 -P4)] (Cp R = Cp" [35] , Cp"' [11] ) analoge Struktur mit s-cis-Tetraphosphabutadiendiyl-"Mitteldeck" vorgeschlagen; es sind jedoch auch zwei micro-h 2:2 -P2-Liganden denkbar. Die Cothermolyse von [{Cp"Ru(CO)2}2] (1a) und [Cp*Fe(h 5 -P5)] (2b) ergibt ein breites Produktbild. Während [Cp"Ru(h 5 -P5)] (3a), das chromatographisch nicht von 2b abgetrennt werden konnte, und [Cp"2Ru2P4] (4a, 6 % Ausbeute) in vergleichsweise geringen Mengen entstehen, können [{Cp"Ru}3P5] (6) in 17 % Ausbeute, [{Cp"Ru}2{Cp*Fe}P5] (7) in 7 % Ausbeute, [{Cp*Fe}2{Cp"Ru}P5] (8) in 22 % Ausbeute und [{Cp"Ru}3{Cp*Fe}(P2)2] (9) in 14 % Ausbeute isoliert werden. Für 9 wird, basierend auf den NMR-spektroskopischen Befunden, eine zu [{CpFe}4(P2)2] (10) [24] analoge Struktur mit einem hier verzerrten Dreiecksdodekaedergerüst vorge-schlagen, dessen vier Ecken der Konnektivität fünf von drei Rutheniumatomen und einem Eisenatom besetzt sind und dessen vier Ecken der Konnektivität vier zwei micro-h 2:2:1:1 -P2-Einheiten einnehmen. Es handelt sich bei 9 wie bei 10 um Cluster vom hypercloso-Typ (n+1 = 8 GEP). [30,31] Röntgenstrukturanalysen zeigen, daß 6, 7 und 8 ebenfalls verzerrt dreiecksdodekaedrische Gerüststrukturen besitzen. Damit ist auch die Struktur der bereits früher synthetisierten und spektroskopisch charakterisierten Komplexe [{Cp R Fe}3P5] (Cp R = Cp*, Cp*') (11b,c) [8] geklärt, deren NMR-Daten auf eine enge Verwandtschaft insbesondere mit 6 hinweisen. Gegenüber 9 bzw. 10 [24] mit einem M4P4-Gerüst (M = allgem. Übergangsmetallatom) ist in den Clustern 6, 7, 8 und 11b,c [8] mit M3P5-Gerüst formal ein 13 VE-Metallkomplex-fragment (Konnektivität fünf; 1 GE) durch ein Phosphoratom (3 GE) ersetzt, wodurch der Übergang zum closo-Strukturtyp des Dreiecksdodekaeders (n+1 = 9 GEP) [30,31] vollzogen wird. Die Cluster 6, 7, 8 und 11b,c [8] enthalten eine bisher unbekannte Koordinationsform der P5-Einheit. Bei der thermischen Umsetzung von [{Cp*Ru(CO)2}2] (1b) mit [Cp*Ru(h 5 -P5)] (3b) erhält man als Hauptprodukt den Dreikernkomplex [{Cp*Ru}3(P4)(P)] (17b, 62 % Ausbeute). Als einziges Nebenprodukt kann [Cp*2Ru2P4] (4b, 5 % Ausbeute) säulen-chromatographisch isoliert werden. Die NMR-Daten von 17b lassen in Analogie zum röntgenstrukturanalytisch charakterisierten [{Cp*'Fe}3(P4)(P){Mo(CO)5}] (18c) [8] auf eine cubanartige Struktur schließen, in der die fünf Phosphoratome in Form einer Isotetraphosphid-Einheit und eines einzelnen Phosphoratoms vorliegen. Die Gesamtzahl von 64 Valenzelektronen ist im Einklang mit drei Metall-Metall-Bindungen [31] . Für 4b ist wie für das voranstehend besprochene Cp"-Derivat 4a eine Pseudo- Tripeldecker-Struktur mit s-cis-Tetraphosphabutadiendiyl-"Mitteldeck" oder mit zwei micro-h 2:2 -P2-Liganden zu diskutieren. Thermolysiert man [{Cp* Ru(CO)2}2] (1c) mit 3b, so erhält man die Komplexe [Cp*'nCp*2-nRu2P4] (n = 0,1,2) (4b,d,c) und [{Cp*'Ru}n{Cp*Ru}3-n(P4)(P)] (n = 1,2,3) (17e,d,c) jeweils als nicht auftrennbare Gemische von analog aufgebauten Verbindungen, die sich nur im Zahlenverhältnis der verschiedenen Cyclopentadienyl-Liganden Cp*' und Cp* unterscheiden. In geringem Umfang beobachtet man dabei auch eine cyclo-P5-Übertragung unter Bildung des literaturbekannten [Cp*'Ru(h 5 -P5)] [7,10] , das im Gemisch mit nicht abreagiertem 3b anfällt. Durch Umsetzung mit [W(CO)5(thf)] gelingt die Komplexierung des dreiecks-dodekaedrischen Clusters [{Cp*Fe}2{Cp"Ru}P5] (8) zum Monoaddukt [{Cp*Fe}2{Cp"Ru}P5{W(CO)5}] (19), während beim Komplexierungsversuch des ebenfalls dreiecksdodekaedrischen Clusters [{Cp*'Fe}3P5] (11c) mit [Mo(CO)5(thf)] [8] eine Gerüstumlagerung zur cubanartig aufgebauten Verbindung [{Cp*'Fe}3(P4)(P){Mo(CO)5}] (18c) erfolgt. Der Strukturvorschlag für 19 basiert auf dem 31 P-NMR-Spektrum. Versuche zur Oxidation von 8 mit gelbem Schwefel bei Raumtemperatur führen zu unspezifischer Zersetzung bzw. Folgereaktionen von 8. Orientierende Versuche mit grauem Selen als milderem Oxidationsmittel deuten darauf hin, daß unter geeigneten Reaktionsbedingungen eine einfache Selenierung am endständigen Phosphoratom des P5-Liganden von 8 erfolgt. Bei der Umsetzung von [{Cp"Ru}3{Cp*Fe}(P2)2] (9) mit gelbem Schwefel können je nach Reaktionsbedingungen bis zu drei Phosphoratome oxidiert werden. Vollständige Sulfurierung wie im Falle von [{CpFe}4(P2S2)2] [24] wird nicht beobachtet. Die Sulfurierung ist regioselektiv. Für einen bestimmten Sulfurierungsgrad wird jeweils nur ein Produkt erhalten. Die Strukturvorschläge für die Cluster 21 23 werden anhand ihrer 31 P-NMR-spektroskopischen Daten abgeleitet.
[Halb]- trocken im Unterstockbereich?
„Untersuchungen meteorologisch-hydrologischer Messgrößen im Weinbau als Anpassungsstrategie an den Klimawandel sowie für eine nachhaltige Wassernutzung von Vitis vinifera [cv. Riesling]. “
Christian Ihrig & Sascha Henninger
RPTU Kaiserslautern
Der vom Menschen verursachte Klimawandel beeinflusst sowohl langfristige Klimaprozesse, als auch das aktuelle, kurzfristige Wettergeschehen in allen Regionen der Erde. Er äußert sich in einer Vielzahl an Phänomenen, die sich je nach Klimagebiet unterschiedlich manifestieren lassen oder auch unterschiedliche Auswirkungen mit sich bringen. Diese Forschungsarbeit beschäftigt sich mit dem Wasserhaushalt von Weinreben im Rahmen des rezenten Klimawandels. Ziel dieses Projektes ist es, mittels meteorologisch-hydrologischen Messgrößen eine Anpassungsstrategie zu generieren, die auf alle Weinbauregionen in Rheinland-Pfalz übertragen werden kann, um Winzer*innen die Möglichkeit zu eröffnen, auf natürlicher Art und Weise der Rebe Wasser zugänglich zu machen.
Durch die Zunahme abiotischer Schäden (z.B. Niederschlag) und die Veränderung der Vegetationszeit sowie die Zunahme invasiver Schaderreger ist vermehrt eine Steigerung der Vulnerabilität des Ökosystems „Wingert“ zu erkennen. Winzer*innen werden aufgrund der Zunahme von Extremwetterereignissen (Hitze-/Dürrephasen) zur langfristigen Bewässerung ihrer Weinbauflächen gezwungen. Große Mengen Wasser werden bereits vereinzelt in Weinbergsregionen gepumpt, was langfristig hinsichtlich eines sinkenden Grundwasserspiegels einen fatalen Fehler darstellt. Die ressourcenschonende Gestaltung des Wasserhaushaltes sollte daher in den Mittelpunkt der Weinbauforschung gestellt werden. Weinbauer*innen sind an regional-/ lokalklimatischen Lösungsmöglichkeiten und Anpassungsstrategien interessiert, um Risiken für die Anbaufrucht reduzieren und auf die lokalklimatischen Auswirkungen des Klimawandels reagieren zu können. Um gegen dieses Risiko anzugehen und den Produktionsausfall zu minimieren, muss die Anpassungsfähigkeit in Sachen Wasserhaushalt der Reben bekräftigt werden. Demzufolge wird das Mikroklima in der Weinbauregion Rheinhessen mittels des Einsatzes der Scholander-Druckkammer untersucht. Die Bestimmung des Wasserstatus hinsichtlich der exakten Bewässerungssteuerung von Weinreben hat sich durch das frühmorgendliche Blattwasser- (Ψpd) und mittägliche Stammwasserpotential (Ψstem) bewährt. Physiologische Prozesse, wie die stomatäre Leitfähigkeit der Blattschließzellen sowie das vegetative Wachstum, aber auch die Photosynthese, sind direkt oder indirekt an Ψpd + Ψstem gekoppelt. Darüber hinaus lässt sich der Wasserhaushalt durch ein an Trockenstandorten angepasstes Bodenpflegesystem, wie zum Beispiel einer flächendeckenden Bodenabdeckung mittels Holzhäcksel, deutlich verbessern. Des Weiteren wird das Mikroklima im Weinberg durch die Laubwandstruktur mitbestimmt, was durch eine gesteigerte Photosyntheseleistung der Laubwand, eine optimale Belüftung und Belichtung gewährleistet wird. Im praktischen Weinbau wird dies durch die Höhe der Laubwand realisiert. Um dem Herbizid im Unterstockraum durch das anstehende Glyphosatverbot eine Alternative zu bieten, entwickelt die Landmaschinenbranche bereits heute alternative Arbeitsgeräte, die eine Möglichkeit darstellen, dem Wuchs des Unkrautes im Unterstockbereich entgegenzuwirken.
Daher ist es von gesteigertem Interesse zu analysieren, inwiefern sich eine Bodenabdeckung im Unterstockbereich von einer flächendeckenden bzw. moderaten Tropfbewässerung in Flachlage unterscheidet. Darüber hinaus sollen Möglichkeiten zur Reduzierung des Wasserverbrauchs und zur Reifeverzögerung (Verminderung des Botrytisbefalls, Verlängerung der Reifedauer, Vermeidung eines zu hohen Alkoholgehaltes) durch eine kürzere Laubwandhöhe beim Riesling in Flachlage in diesem Projekt erprobt werden. Als Versuchsvarianten dienen vier Variationen, um abgrenzbare und eindeutige Ergebnisse erzielen zu können (V1: Tropfbewässerung; V2: Unterstockabdeckung Holzhäcksel; V3: Flächendeckende Holzhäcksel; V4: Kontrollvariante).
We have presented here a two-dimensional kinetical scheme for equations governing the motion of a compressible flow of an ideal gas (air) based on the Kaniel method. The basic flux functions are computed analytically and have been used in the organization of the flux computation. The algorithm is implemented and tested for the 1D shock and 2D shock-obstacle interaction problems.
In this paper a three dimensional stochastic model for the lay-down of fibers on a moving conveyor belt in the production process of nonwoven materials is derived. The model is based on stochastic diferential equations describing the resulting position of the fiber on the belt under the influence of turbulent air ows. The model presented here is an extension of an existing surrogate model, see [6, 3].
The World Wide Web is a medium through which a manufacturer may allow Internet visitors to customize or compose his products. Due to missing or rapidly changing standards these applications are often restricted to relatively simple CGI or JAVA based scripts. Usually, results like images or movies are stored in a database and are transferred on demand to the web-user. Viper (Visualisierung parametrisch editierbarer Raumkomponenten) is a Toolkit [VIP96] written in C++ and JAVA which provides 3D-modeling and visualization methodsfor developing complex web-based applications. The Toolkit has been designed to built a prototype, which can be used to construct and visualize prefabricated homes on the Internet. Alternative applications are outlined in this paper. Within Viper, all objects are stored in a scene graph (VSSG ), which is the basic data structure of the Toolkit. To show the concept and structure of the Toolkit, functionality, and implementation of the prototype are described.
The classic approach in robust optimization is to optimize the solution with respect to the worst case scenario. This pessimistic approach yields solutions that perform best if the worst scenario happens, but also usually perform bad on average. A solution that optimizes the average performance on the other hand lacks in worst-case performance guarantee.
In practice it is important to find a good compromise between these two solutions. We propose to deal with this problem by considering it from a bicriteria perspective. The Pareto curve of the bicriteria problem visualizes exactly how costly it is to ensure robustness and helps to choose the solution with the best balance between expected and guaranteed performance.
Building upon a theoretical observation on the structure of Pareto solutions for problems with polyhedral feasible sets, we present a column generation approach that requires no direct solution of the computationally expensive worst-case problem. In computational experiments we demonstrate the effectivity of both the proposed algorithm, and the bicriteria perspective in general.
A branch-and-cut approach and alternative formulations for thetraveling salesman problem with drone
(2020)
In this paper, we are interested in studying thetraveling salesman problem withdrone(TSP-D). Given a set of customers and a truck that is equipped with a singledrone, the TSP-D asks that all customers are served exactly once and minimal deliv-ery time is achieved. We provide two compact mixed integer linear programmingformulations that can be used to address instances with up to 10 customer within afew seconds. Notably, we introduce a third formulation for the TSP-D with an expo-nential number of constraints. The latter formulation is suitable to be solved by abranch-and-cut algorithm. Indeed, this approach can be used to find optimal solu-tions for several instances with up to 20 customers within 1 hour, thus challenging thecurrent state-of-the-art in solving the TSP-D. A detailed numerical study providesan in-depth comparison on the effectiveness of the proposed formulations. More-over, we reveal further details on the operational characteristics of a drone-assisteddelivery system. By using three different sets of benchmark instances, considera-tion is given to various assumptions that affect, for example, technological droneparameters and the impact of distance metrics.
We consider the problem of evacuating a region with the help of buses. For a given set of possible collection points where evacuees gather, and possible shelter locations where evacuees are brought to, we need to determine both collection points and shelters we would like to use, and bus routes that evacuate the region in minimum time.
We model this integrated problem using an integer linear program, and present a branch-cut-and-price algorithm that generates bus tours in its pricing step. In computational experiments we show that our approach is able to solve instances of realistic size in sufficient time for practical application, and considerably outperforms the usage of a generic ILP solver.
A building-block model reveals new insights into the biogenesis of yeast mitochondrial ribosomes
(2020)
Most of the mitochondrial proteins in yeast are encoded in the nuclear genome, get synthesized by cytosolic ribosomes and are imported via TOM and TIM23 into the matrix or other subcompartments of mitochondria. The mitochondrial DNA in yeast however also encodes a small set of 8 proteins from which most are hydrophobic membrane proteins and build core components of the OXPHOS complexes. They get synthesized by mitochondrial ribosomes which are descendants of bacterial ribosomes and still have some similarities to them. On the other hand, mitochondrial ribosomes experienced various structural and functional changes during evolution that specialized them for the synthesis of the mitochondrial encoded membrane proteins. The mitoribosome contains mitochondria-specific ribosomal proteins and replaced the bacterial 5S rRNA by mitochondria-specific proteins and rRNA extensions. Furthermore, the mitoribosome is tethered to the inner mitochondrial membrane to facilitate a co-translational insertion of newly synthesized proteins. Thus, also the assembly process of mitoribosomes differs from that of bacteria and is to date not well understood.
Therefore, the biogenesis of mitochondrial ribosomes in yeast should be investigated. To this end, a strain was generated in which the gene of the mitochondrial RNA-polymerase RPO41 is under control of an inducible GAL10-promoter. Since the scaffold of ribosomes is built by ribosomal RNAs, the depletion of the RNA-polymerase subsequently leads to a loss of mitochondrial ribosomes. Reinduction of Rpo41 initiates the assembly of new mitoribosomes, which makes this strain an attractive model to study mitoribosome biogenesis.
Initially, the effects of Rpo41 depletion on cellular and mitochondrial physiology was investigated. Upon Rpo41 depletion, growth on respiratory glycerol medium was inhibited. Furthermore, mitochondrial ribosomal 21S and 15S rRNA was diminished and mitochondrial translation was almost completely absent. Also, mitochondrial DNA was strongly reduced due to the fact that mtDNA replication requires RNA primers that get synthesized by Rpo41.
Next, the effect of reinduction of Rpo41 on mitochondria was tested. Time course experiments showed that mitochondrial translation can partially recover from 48h Rpo41 depletion within a timeframe of 4.5h. Sucrose gradient sedimentation experiments further showed that the mitoribosomal constitution was comparable to wildtype control samples during the time course of 4.5h of reinduction, suggesting that the ribosome assembly is not fundamentally altered in Gal-Rpo41 mitochondria. In addition, the depletion time was found to be critical for recovery of mitochondrial translation and mitochondrial RNA levels. It was observed that after 36h of Rpo41 depletion, the rRNA levels and mitochondrial translation recovered to almost 100%, but only within a time course of 10h.
Finally, mitochondria from Gal-Rpo41 cells isolated after different timepoints of reinduction were used to perform complexome profiling and the assembly of mitochondrial protein complexes was investigated. First, the steady state conditions and the assembly process of mitochondrial respiratory chain complexes were monitored. The individual respiratory chain complexes and the super-complexes of complex III, complex IV and complex V were observed. Furthermore, it was seen that they recovered from Rpo41 depletion within 4.5h of reinduction. Complexome profiles of the mitoribosomal small and large subunit discovered subcomplexes of mitoribosomal proteins that were assumed to form prior to their incorporation into assembly intermediates. The complexome profiles after reinduction indeed showed the formation of these subcomplexes before formation of the fully assembled subunit. In the mitochondrial LSU one subcomplex builds the membrane facing protuberance and a second subcomplex forms the central protuberance. In contrast to the preassembled subcomplexes, proteins that were involved in early assembly steps were exclusively found in the fully assembled subunit. Proteins that assemble at the periphery of the mitoribosome during intermediate and late assembly steps where found in soluble form suggesting a pool of unassembled proteins that supply assembly intermediates with proteins.
Taken together, the findings of this thesis suggest a so far unknow building-block model for mitoribosome assembly in which characteristic structures of the yeast mitochondrial ribosome form preassembled subcomplexes prior to their incorporation into the mitoribosome.
3D integration of solid-state memories and logic, as demonstrated by the Hybrid Memory Cube (HMC), offers major opportunities for revisiting near-memory computation and gives new hope to mitigate the power and performance losses caused by the “memory wall”. In this paper we present the first exploration steps towards design of the Smart Memory Cube (SMC), a new Processor-in-Memory (PIM) architecture that enhances the capabilities of the logic-base (LoB) in HMC. An accurate simulation environment has been developed, along with a full featured software stack. All offloading and dynamic overheads caused by the operating system, cache coherence, and memory management are considered, as well. Benchmarking results demonstrate up to 2X performance improvement in comparison with the host SoC, and around 1.5X against a similar host-side accelerator. Moreover, by scaling down the voltage and frequency of PIM’s processor it is possible to reduce energy by around 70% and 55% in comparison with the host and the accelerator, respectively.
Contrary to symbolic learning approaches, which represent a learned concept explicitly, case-based approaches describe concepts implicitly by a pair (CB; sim), i.e. by a measure of similarity sim and a set CB of cases. This poses the question if there are any differences concerning the learning power of the two approaches. In this article we will study the relationship between the case base, the measure of similarity, and the target concept of the learning process. To do so, we transform a simple symbolic learning algorithm (the version space algorithm) into an equivalent case- based variant. The achieved results strengthen the hypothesis of the equivalence of the learning power of symbolic and case-based methods and show the interdependency between the measure used by a case-based algorithm and the target concept.
Retrieving multiple cases is supposed to be an adequate retrieval strategy for guiding partial-order planners because of the recognized flexibility of these planners to interleave steps in the plans. Cases are combined by merging them. In this paper, we will examine two different kinds of merging cases in the context of partial-order planning. We will see that merging cases can be very difficult if the cases are merged eagerly. On the other hand, if cases are merged by avoiding redundant steps, the guidance of the additional cases tends to decrease with the number of covered goals and retrieved cases in domains having a certain kind of interactions. Thus, to retrieve a single case covering many of the goals of the problem or to retrieve fewer cases covering many of the goals is at least equally effective as to retrieve several cases covering all goals in these domains.
A Case Study on Specifikation,Detection and Resolution of IN Feature Interactions with Estelle
(1994)
We present an approach for the treatment of Feature Interactions in Intelligent Networks. The approach is based on the formal description technique Estelle and consists of three steps. For the first step, a specification style supporting the integration of additional features into a basic service is introduced . As a result, feature integration is achieved by adding specification text, i.e . on a purely syntactical level. The second step is the detection of feature interactions resulting from the integration of additional features. A formal criterion is given that can be used for the automatic detection of a particular class of feature interactions. In the third step, previously detected feature interactions are resolved. An algorithm has been devised that allows the automatical incorporation of high-level design decisions into the formal specification. The presented approach is applied to the Basic Call Service and several supplementary interacting features.
A large set of criteria to evaluate formal methods for reactive systems is presented. To make this set more comprehensible, it is structured according to a Concept-Model of formal methods. It is made clear that it is necessary to make the catalogue more specific before applying it. Some of the steps needed to do so are explained. As an example the catalogue is applied within the context of the application domain building automation systems to three different formal methods: SDL, statecharts, and a temporallogic.
In this paper we give the definition of a solution concept in multicriteria combinatorial optimization. We show how Pareto, max-ordering and lexicographically optimal solutions can be incorporated in this framework. Furthermore we state some properties of lexicographic max-ordering solutions, which combine features of these three kinds of optimal solutions. Two of these properties, which are desirable from a decision maker" s point of view, are satisfied if and only of the solution concept is that of lexicographic max-ordering.
In this paper we develop a data-driven mixture of vector autoregressive models with exogenous components. The process is assumed to change regimes according to an underlying Markov process. In contrast to the hidden Markov setup, we allow the transition probabilities of the underlying Markov process to depend on past time series values and exogenous variables. Such processes have potential applications to modeling brain signals. For example, brain activity at time t (measured by electroencephalograms) will can be modeled as a function of both its past values as well as exogenous variables (such as visual or somatosensory stimuli). Furthermore, we establish stationarity, geometric ergodicity and the existence of moments for these processes under suitable conditions on the parameters of the model. Such properties are important for understanding the stability properties of the model as well as deriving the asymptotic behavior of various statistics and model parameter estimators.
A new approach for modelling time that does not rely on the concept of a clock is proposed. In order to establish a notion of time, system behaviour is represented as a joint progression of multiple threads of control, which satisfies a certain set of axioms. We show that the clock-independent time model is related to the well-known concept of a global clock and argue that both approaches establish the same notion of time.
Coloring terms (rippling) is a technique developed for inductive theorem proving which uses syntactic differences of terms to guide the proof search. Annotations (colors) to terms are used to maintain this information. This technique has several advantages, e.g. it is highly goal oriented and involves little search. In this paper we give a general formalization of coloring terms in a higher-order setting. We introduce a simply-typed lambda calculus with color annotations and present an appropriate (pre-)unification algorithm. Our work is a formal basis to the implementation of rippling in a higher-order setting which is required e.g. in case of middle-out reasoning. Another application is in the construction of natural language semantics, where the color annotations rule out linguistically invalid readings that are possible using standard higher-order unification.
This paper develops a sound and complete transformation-based algorithm forunification in an extensional order-sorted combinatory logic supporting constantoverloading and a higher-order sort concept. Appropriate notions of order-sortedweak equality and extensionality - reflecting order-sorted fij-equality in thecorresponding lambda calculus given by Johann and Kohlhase - are defined, andthe typed combinator-based higher-order unification techniques of Dougherty aremodified to accommodate unification with respect to the theory they generate. Thealgorithm presented here can thus be viewed as a combinatory logic counterpartto that of Johann and Kohlhase, as well as a refinement of that of Dougherty, andprovides evidence that combinatory logic is well-suited to serve as a framework forincorporating order-sorted higher-order reasoning into deduction systems aimingto capitalize on both the expressiveness of extensional higher-order logic and theefficiency of order-sorted calculi.
In grinding, the crystal grain size of the workpiece material is relatively same range compared to the removal depth. This raises a question if an anisotropic material model, which considers the effect of the crystal grain size and orientations, would better predict the process forces when compared to an isotropic material model. Initially, a simple micro-indentation process is chosen to compare the two models. In this work, a crystal plasticity model and an isotropic Johnson-Cooke plasticity model are employed to simulate micro-identation of a twinning induced plasticity (TWIP) steel. The results of the two models are compared using the force-displacement curves from the micro-indentation experiments. In the future, the study will be extended to describe the material removal process during a single grit scratch test.
In this work, we analyze two important and simple models of short rates, namely Vasicek and CIR models. The models are described and then the sensitivity of the models with respect to changes in the parameters are studied. Finally, we give the results for the estimation of the model parameters by using two different ways.
Let \(a_1,\dots,a_n\) be independent random points in \(\mathbb{R}^d\) spherically symmetrically but not necessarily identically distributed. Let \(X\) be the random polytope generated as the convex hull of \(a_1,\dots,a_n\) and for any \(k\)-dimensional subspace \(L\subseteq \mathbb{R}^d\) let \(Vol_L(X) :=\lambda_k(L\cap X)\) be the volume of \(X\cap L\) with respect to the \(k\)-dimensional Lebesgue measure \(\lambda_k, k=1,\dots,d\). Furthermore, let \(F^{(i)}\)(t):= \(\bf{Pr}\) \(\)(\(\Vert a_i \|_2\leq t\)),
\(t \in \mathbb{R}^+_0\) , be the radial distribution function of \(a_i\). We prove that the expectation
functional \(\Phi_L\)(\(F^{(1)}, F^{(2)},\dots, F^{(n)})\) := \(E(Vol_L(X)\)) is strictly decreasing in
each argument, i.e. if \(F^{(i)}(t) \le G^{(i)}(t)t\), \(t \in {R}^+_0\), but \(F^{(i)} \not\equiv G^{(i)}\), we show \(\Phi\) \((\dots, F^{(i)}, \dots\)) > \(\Phi(\dots,G^{(i)},\dots\)). The proof is clone in the more general framework
of continuous and \(f\)- additive polytope functionals.
Treating polyatomic gases in kinetic gas theory requires an appropriate molecule model taking into account the additional internal structure of the gas particles. In this paper we describe two such models, each arising from quite different approaches to this problem. A simulation scheme for solving the corresponding kinetic equations is presented and some numerical results to 1D shockwaves are compared.
Simulation methods like DSMC are an efficient tool to compute rarefied gas flows. Using supercomputers it is possible to include various real gas effects like vibrational energies or chemical reactions in a gas mixture. Nevertheless it is still necessary to improve the accuracy of the current simulation methods in order to reduce the computational effort. To support this task the paper presents a comparison of the classical DSMC method with the so called finite Pointset Method. This new approach was developed during several years in the framework of the European space project HERMES. The comparison given in the paper is based on two different testcases: a spatially homogeneous relaxation problem and a 2-dimensional axisymmetric flow problem at high Mach numbers.
We consider the problem of evacuating an urban area caused by a natural or man-made disaster. There are several planning aspects that need to be considered in such a scenario, which are usually considered separately, due to their computational complexity. These aspects include: Which shelters are used to accommodate evacuees? How to schedule public transport for transit-dependent evacuees? And how do public and individual traffic interact? Furthermore, besides evacuation time, also the risk of the evacuation needs to be considered.
We propose a macroscopic multi-criteria optimization model that includes all of these questions simultaneously. As a mixed-integer programming formulation cannot handle instances of real-world size, we develop a genetic algorithm of NSGA-II type that is able to generate feasible solutions of good quality in reasonable computation times.
We extend the applicability of these methods by also considering how to aggregate instance data, and how to generate solutions for the original instance starting from a reduced solution.
In computational experiments using real-world data modelling the cities of Nice in France and Kaiserslautern in Germany, we demonstrate the effectiveness of our approach and compare the trade-off between different levels of data aggregation.
This paper describes a system that supports softwaredevelopment processes in virtual software corporations. A virtual software corporation consists of a set of enterprisesthat cooperate in projects to fulfill customer needs. Contracts are negotiated in the whole lifecycle of asoftware development project. The negotiations really influence the performance of a company. Therefore, it isuseful to support negotiations and planning decisions with software agents. Our approach integrates software agentapproaches for negotiation support with flexible multiserver workflow engines.
In this article we give a sufficient condition that a simply connected flexible body does not penetrate itself, if it is subjected to a continuous deformation. It is shown that the deformation map is automatically injective, if it is just locally injective and injective on the boundary of the body. Thereby, it is very remarkable that no higher regularity assumption than continuity for the deformation map is required. The proof exclusively relies on homotopy methods and the Jordan-Brouwer separation theorem.
A Consistent Large Eddy Approach for Lattice Boltzmann Methods and its Application to Complex Flows
(2015)
Lattice Boltzmann Methods have shown to be promising tools for solving fluid flow problems. This is related to the advantages of these methods, which are among others, the simplicity in handling complex geometries and the high efficiency in calculating transient flows. Lattice Boltzmann Methods are mesoscopic methods, based on discrete particle dynamics. This is in contrast to conventional Computational Fluid Dynamics methods, which are based on the solution of the continuum equations. Calculations of turbulent flows in engineering depend in general on modeling, since resolving of all turbulent scales is and will be in near future far beyond the computational possibilities. One of the most auspicious modeling approaches is the large eddy simulation, in which the large, inhomogeneous turbulence structures are directly computed and the smaller, more homogeneous structures are modeled.
In this thesis, a consistent large eddy approach for the Lattice Boltzmann Method is introduced. This large eddy model includes, besides a subgrid scale model, appropriate boundary conditions for wall resolved and wall modeled calculations. It also provides conditions for turbulent domain inlets. For the case of wall modeled simulations, a two layer wall model is derived in the Lattice Boltzmann context. Turbulent inlet conditions are achieved by means of a synthetic turbulence technique within the Lattice Boltzmann Method.
The proposed approach is implemented in the Lattice Boltzmann based CFD package SAM-Lattice, which has been created in the course of this work. SAM-Lattice is feasible of the calculation of incompressible or weakly compressible, isothermal flows of engineering interest in complex three dimensional domains. Special design targets of SAM-Lattice are high automatization and high performance.
Validation of the suggested large eddy Lattice Boltzmann scheme is performed for pump intake flows, which have not yet been treated by LBM. Even though, this numerical method is very suitable for this kind of vortical flows in complicated domains. In general, applications of LBM to hydrodynamic engineering problems are rare. The results of the pump intake validation cases reveal that the proposed numerical approach is able to represent qualitatively and quantitatively the very complex flows in the intakes. The findings provided in this thesis can serve as the basis for a broader application of LBM in hydrodynamic engineering problems.
We propose a constraint-based approach for the two-dimensional rectangular packing problem with orthogonal orientations. This problem is to arrange a set of rectangles that can be rotated by 90 degrees into a rectangle of minimal size such that no two rectangles overlap. It arises in the placement of electronic devices during the layout of 2.5D System-in-Package integrated electronic systems. Moffitt et al. [8] solve the packing without orientations with a branch and bound approach and use constraint propagation. We generalize their propagation techniques to allow orientations. Our approach is compared to a mixed-integer program and we provide results that outperform it.
The notion of Q-Gorenstein smoothings has been introduced by Kollar. ([KoJ], 6.2.3). This notion is essential for formulating Kollar's conjectures on smoothing components for rational surface singularities. He conjectures, loosely speaking, that every smoothing of a rational surface singularity can be obtained by blowing down a deformation of a partial resolution, this partial resolution having the property (among others) that the singularities occuring on it all have qG-smoothings. (For more details and precise statements see [Ko], ch. 6.). It is therefore of interest to construct singularities having qG-smoothings.
Beamforming performs spatial filtering to preserve the signal from given directions of interest while suppressing interfering signals and noise arriving from other directions.
For example, a microphone array equipped with beamforming algorithm could preserve the sound coming from a target speaker and suppress sounds coming from other speakers.
Beamformer has been widely used in many applications such as radar, sonar, communication, and acoustic systems.
A data-independent beamformer is the beamformer whose coefficients are independent on sensor signals, it normally uses less computation since the coefficients are computed once. Moreover, its coefficients are derived from the well-defined statistical models, then it produces less artifacts. The major drawback of this beamforming class is its limitation to the interference suppression.
On the other hand, an adaptive beamformer is a beamformer whose coefficients depend on or adapt to sensor signals. It is capable of suppressing the interference better than a data-independent beamforming but it suffers from either too much distortion of the signal of interest or less noise reduction when the updating rate of coefficients does not synchronize with the changing rate of the noise model. Besides, it is computationally intensive since the coefficients need to be updated frequently.
In acoustic applications, the bandwidth of signals of interest extends over several octaves, but we always expect that the characteristic of the beamformer is invariant with regard to the bandwidth of interest. This can be achieved by the so-called broadband beamforming.
Since the beam pattern of conventional beamformers depends on the frequency of the signal, it is common to use a dense and uniform array for the broadband beamforming to guarantee some essential performances together, such as frequency-independence, less sensitive to white noise, high directivity factor or high front-to-back ratio. In this dissertation, we mainly focus on the sparse array of which the aim is to use fewer sensors in the array,
while simultaneously assuring several important performances of the beamformer.
In the past few decades, many design methodologies for sparse arrays have been proposed and were applied in a variety of practical applications.
Although good results were presented, there are still some restrictions, such as the number of sensors is large, the designed beam pattern must be fixed, the steering ability is limited and the computational complexity is high.
In this work, two novel approaches for the sparse array design taking a hypothesized uniform array as a basis are proposed, that is, one for data-independent beamformers and the another for adaptive beamformers.
As an underlying component of the proposed methods, the dissertation introduces some new insights into the uniform array with broadband beamforming. In this context, a function formulating the relations between the sensor coefficients and its beam pattern over frequency is proposed. The function mainly contains the coordinate transform and inverse Fourier transform.
Furthermore, from the bijection of the function and broadband beamforming perspective, we propose the lower and upper bounds for the inter-distance of sensors. Within these bounds, the function is a bijective function that can be utilized to design the uniform array with broadband beamforming.
For data-independent beamforming, many studies have focused on optimization procedures to seek the sparse array deployment. This dissertation presents an alternative approach to determine the location of sensors.
Starting with a weight spectrum of a virtual dense and uniform array, some techniques are used, such as analyzing a weight spectrum to determine the critical sensors, applying the clustering technique to group the sensors into different groups and selecting representative sensors for each group.
After the sparse array deployment is specified, the optimization technique is applied to find the beamformer coefficients. The proposed method helps to save the computation time in the design phase and its beamformer performance outperforms other state-of-the-art methods in several aspects such as the higher white noise gain, higher directivity factor or more frequency-independence.
For adaptive beamforming, the dissertation attempts to design a versatile sparse microphone array that can be used for different beam patterns.
Furthermore, we aim to reduce the number of microphones in the sparse array while ensuring that its performance can continue to compete with a highly dense and uniform array in terms of broadband beamforming.
An irregular microphone array in a planar surface with the maximum number of distinct distances between the microphones is proposed.
It is demonstrated that the irregular microphone array is well-suited to sparse recovery algorithms that are used to solve underdetermined systems with subject to sparse solutions. Here, a sparse solution is the sound source's spatial spectrum that need to be reconstructed from microphone signals.
From the reconstructed sound sources, a method for array interpolation is presented to obtain an interpolated dense and uniform microphone array that performs well with broadband beamforming.
In addition, two alternative approaches for generalized sidelobe canceler (GSC) beamformer are proposed. One is the data-independent beamforming variant, the other is the adaptive beamforming variant. The GSC decomposes beamforming into two paths: The upper path is to preserve the desired signal, the lower path is to suppress the desired signal. From a beam pattern viewpoint, we propose an improvement for GSC, that is, instead of using the blocking matrix in the lower path to suppress the desired signal, we design a beamformer that contains the nulls at the look direction and at some other directions. Both approaches are simple beamforming design methods and they can be applied to either sparse array or uniform array.
Lastly, a new technique for direction-of-arrival (DOA) estimation based on the annihilating filter is also presented in this dissertation.
It is based on the idea of finite rate of innovation to reconstruct the stream of Diracs, that is, identifying an annihilating filter/locator filter for a few uniform samples and the position of the Diracs are then related to the roots of the filter. Here, an annihilating filter is the filter that suppresses the signal, since its coefficient vector is always orthogonal to every frame of signal.
In the DOA context, we regard an active source as a Dirac associated with the arrival direction, then the directions of active sources can be derived from the roots of the annihilating filter. However,
the DOA obtained by this method is sensitive to noise and the number of DOAs is limited.
To address these issues, the dissertation proposes a robust method to design the annihilating filter and to increase the degree-of-freedom of the measurement system (more active sources can be detected) via observing multiple data frames.
Furthermore, we also analyze the performance of DOA with diffuse noise and propose an extended multiple signal classification algorithm that takes diffuse noise into account. In the simulation,
it shows, that in the case of diffuse noise, only the extended multiple signal classification algorithm can estimate the DOAs properly.
A counter-based read circuit tolerant to process variation for low-voltage operating STT-MRAM
(2016)
The capacity of embedded memory on LSIs has kept increasing. It is important to reduce the leakage power of embedded memory for low-power LSIs. In fact, the ITRS predicts that the leakage power in embedded memory will account for 40% of all power consumption by 2024 [1]. A spin transfer torque magneto-resistance random access memory (STT-MRAM) is promising for use as non-volatile memory to reduce the leakage power. It is useful because it can function at low voltages and has a lifetime of over 1016 write cycles [2]. In addition, the STT-MRAM technology has a smaller bit cell than an SRAM. Making the STT-MRAM is suitable for use in high-density products [3–7]. The STT-MRAM uses magnetic tunnel junction (MTJ). The MTJ has two states: a parallel state and an anti-parallel state. These states mean that the magnetization direction of the MTJ’s layers are the same or different. The directions pair determines the MTJ’s magneto- resistance value. The states of MTJ can be changed by the current flowing. The MTJ resistance becomes low in the parallel state and high in the anti-parallel state. The MTJ potentially operates at less than 0.4 V [8]. In other hands, it is difficult to design peripheral circuitry for an STT-MRAM array at such a low voltage. In this paper, we propose a counter-based read circuit that functions at 0.4 V, which is tolerant of process variation and temperature fluctuation.
In cake filtration processes, where particles in a suspension are separated by forming a filter
cake on the filter medium, the resistances of filter cake and filter medium cause a specific pressure
drop which consequently defines the process energy effort. The micromechanics of the filter cake
formation (interactions between particles, fluid, other particles and filter medium) must be considered
to describe pore clogging, filter cake growth and consolidation correctly. A precise 3D modeling
approach to describe these effects is the resolved coupling of the Computational Fluid Dynamics with
the Discrete Element Method (CFD-DEM). This work focuses on the development and validation of a
CFD-DEM model, which is capable to predict the filter cake formation during solid-liquid separation
accurately. The model uses the Lattice-Boltzmann Method (LBM) to directly solve the flow equations
in the CFD part of the coupling and the DEM for the calculation of particle interactions. The developed
model enables the 4-way coupling to consider particle-fluid and particle-particle interactions. The
results of this work are presented in two steps. First, the developed model is validated with an
empirical model of the single particle settling velocity in the transition regime of the fluid-particle
flow. The model is also enhanced with additional particles to determine the particle-particle influence.
Second, the separation of silica glass particles from water in a pressurized housing at constant pressure
is experimentally investigated. The measured filter cake, filter medium and interference resistances
are in a good agreement with the results of the 3D simulations, demonstrating the applicability of the
resolved CFD-DEM coupling for analyzing and optimizing cake filtration processes.
The growing computational power enables the establishment of the Population Balance Equation (PBE)
to model the steady state and dynamic behavior of multiphase flow unit operations. Accordingly, the twophase
flow
behavior inside liquid-liquid extraction equipment is characterized by different factors. These
factors include: interactions among droplets (breakage and coalescence), different time scales due to the
size distribution of the dispersed phase, and micro time scales of the interphase diffusional mass transfer
process. As a result of this, the general PBE has no well known analytical solution and therefore robust
numerical solution methods with low computational cost are highly admired.
In this work, the Sectional Quadrature Method of Moments (SQMOM) (Attarakih, M. M., Drumm, C.,
Bart, H.-J. (2009). Solution of the population balance equation using the Sectional Quadrature Method of
Moments (SQMOM). Chem. Eng. Sci. 64, 742-752) is extended to take into account the continuous flow
systems in spatial domain. In this regard, the SQMOM is extended to solve the spatially distributed
nonhomogeneous bivariate PBE to model the hydrodynamics and physical/reactive mass transfer
behavior of liquid-liquid extraction equipment. Based on the extended SQMOM, two different steady
state and dynamic simulation algorithms for hydrodynamics and mass transfer behavior of liquid-liquid
extraction equipment are developed and efficiently implemented. At the steady state modeling level, a
Spatially-Mixed SQMOM (SM-SQMOM) algorithm is developed and successfully implemented in a onedimensional
physical spatial domain. The integral spatial numerical flux is closed using the mean mass
droplet diameter based on the One Primary and One Secondary Particle Method (OPOSPM which is the
simplest case of the SQMOM). On the other hand the hydrodynamics integral source terms are closed
using the analytical Two-Equal Weight Quadrature (TEqWQ). To avoid the numerical solution of the
droplet rise velocity, an analytical solution based on the algebraic velocity model is derived for the
particular case of unit velocity exponent appearing in the droplet swarm model. In addition to this, the
source term due to mass transport is closed using OPOSPM. The resulting system of ordinary differential
equations with respect to space is solved using the MATLAB adaptive Runge–Kutta method (ODE45). At
the dynamic modeling level, the SQMOM is extended to a one-dimensional physical spatial domain and
resolved using the finite volume method. To close the mathematical model, the required quadrature nodes
and weights are calculated using the analytical solution based on the Two Unequal Weights Quadrature
(TUEWQ) formula. By applying the finite volume method to the spatial domain, a semi-discreet ordinary
differential equation system is obtained and solved. Both steady state and dynamic algorithms are
extensively validated at analytical, numerical, and experimental levels. At the numerical level, the
predictions of both algorithms are validated using the extended fixed pivot technique as implemented in
PPBLab software (Attarakih, M., Alzyod, S., Abu-Khader, M., Bart, H.-J. (2012). PPBLAB: A new
multivariate population balance environment for particulate system modeling and simulation. Procedia
Eng. 42, pp. 144-562). At the experimental validation level, the extended SQMOM is successfully used
to model the steady state hydrodynamics and physical and reactive mass transfer behavior of agitated
liquid-liquid extraction columns under different operating conditions. In this regard, both models are
found efficient and able to follow liquid extraction column behavior during column scale-up, where three
column diameters were investigated (DN32, DN80, and DN150). To shed more light on the local
interactions among the contacted phases, a reduced coupled PBE and CFD framework is used to model
the hydrodynamic behavior of pulsed sieve plate columns. In this regard, OPOSPM is utilized and
implemented in FLUENT 18.2 commercial software as a special case of the SQMOM. The dropletdroplet
interactions
(breakage
and
coalescence)
are
taken
into
account
using
OPOSPM,
while
the
required
information
about
the
velocity
field
and
energy
dissipation
is
calculated
by
the
CFD
model.
In
addition
to
this,
the proposed coupled OPOSPM-CFD framework is extended to include the mass transfer. The
proposed framework is numerically tested and the results are compared with the published experimental
data. The required breakage and coalescence parameters to perform the 2D-CFD simulation are estimated
using PPBLab software, where a 1D-CFD simulation using a multi-sectional gird is performed. A very
good agreement is obtained at the experimental and the numerical validation levels.
A new algorithm for optimization problems with three objective functions is presented which computes a representation for the set of nondominated points. This representation is guaranteed to have a desired coverage error and a bound on the number of iterations needed by the algorithm to meet this coverage error is derived. Since the representation does not necessarily contain nondominated points only, ideas to calculate bounds for the representation error are given. Moreover, the incorporation of domination during the algorithm and other quality measures are discussed.
Nucleophilic substitution of [(η5-cyclopentadienyl)(η6-chlorobenzene)iron(II)] hexafluorophosphate with sodium imidazolate resulted in the formation of [(η5-cyclopentadienyl)(η6-phenyl)iron(II)]imidazole hexafluorophosphate. The corresponding dicationic imidazolium salt, which was obtained by treating this imidazole precursor with methyl iodide, underwent cyclometallation with bis[dichlorido(η5-1,2,3,4,5-pentamethylcyclopentadienyl]iridium(III) in the presence of triethyl amine. The resulting bimetallic iridium(III) complex is the first example of an NHC complex bearing a cationic and cyclometallated [(η5-cyclopentadienyl)(η6-phenyl)iron(II)]+ substituent. As its iron(II) precursors, the bimetallic iridium(III) complex was fully characterized by means of spectroscopy, elemental analysis and single crystal X-ray diffraction. In addition, it was investigated in a catalytic study, wherein it showed high activity in transfer hydrogenation compared to its neutral analogue having a simple phenyl instead of a cationic [(η5-cyclopentadienyl)(η6-phenyl)iron(II)]+ unit at the NHC ligand.
We study the sensor fault estimation and accommodation problems in a data-driven \(\mathcal{H}_\infty\) setting, leading to a data-driven sensor fault-tolerant control scheme. First, we formulate the fault estimation problem as a finite-horizon minimax \(\mathcal{H}_\infty\)-optimization problem in a data-driven setup, whose solution yields the fault estimate. The estimated fault is then used for output compensation. This compensated output and the experimental input are used to achieve certain control objectives in a data-driven \(\mathcal{H}_\infty\) setting. Next, the data-driven \(\mathcal{H}_\infty\) fault estimation and control problems are solved using a subspace predictor-based approach. Finally, the proposed algorithm is applied to the steering subsystem of the remotely operated underwater vehicle.
The concept of the Virtual Software Corporation ( VSC) has recently become a practical reality as a result of advances in communication and distributed technologies. However, there are significant difficulties with the management of the software development process within a VSC. The main problem is the significantly increased communicational complexity of the process model for such developments. The more classic managerial hierarchy is generally replaced by a "flatter" network of commitments. Therefore new solution approaches are required to provide the necessary process support. The purpose of this paper is to present a solution approach which models the process based on deontic logic. The approach has been validated against a case study where it was used to model commitments and inter-human communications within the software development process of a VSC. The use of the formalism is exemplified through a prototype system using a layered multi-agent architecture.
The present thesis describes the development and the evaluation of a design procedure of inducer with arbitrary meridional and blade shape. This special type of pump impeller, which is usually mounted upstream of a main pump impeller, is employed in many applications demanding the realization of low NPSH values. An inducer basically increases suction performance by producing mostly a small pressure rise while allowing for a greater degree of cavitation, that is the formation of vapor bubbles, at its inlet than a conventional pump impeller. This is achieved by specially designed blade channels promoting the collapse of the produced vapor bubbles.
The main focus of the present thesis is the description of the design method, which enables the generation of the three-dimensional blade geometry. The method is based on a parametric representation of the geometry considering the particular requirements for inducers and the publicly available design practice. Within this approach the sequence of design steps is adapted from the classical design process of mixed flow and radial impellers. As a consequence leading and trailing edge blade angles are determined based on simplifications and certain empirical assumptions for multiple blade sections and are used to design the blade camber curves. Along the camber curves the blade profile is generated following a thickness distribution that has to be prescribed. A special feature of the newly developed method is that arbitrary shaped, asymmetric thickness distributions can be realized.
Due to the detailed description of the design and calculation steps a fully comprehensible procedure is outlined, which covers the development of inducer bladings from an initial set of duty parameters to the final three-dimensional blade geometry.
The components involved in the design procedure are tested by designing two exemplary inducers and they are assessed by comparison with numerical simulations. Functioning of these inducers in the real application is finally demonstrated with water tests.
The main result of this dissertation is a design software for inducers allowing for the design of three-dimensional, asymmetrically profiled bladings. The developed software is free of commercial third-party libraries. As a consequence a program is available that can be modified and extended as desired. As potential future development goals inducers with splitter and tandem blades as well as an integrated design of inducer and impeller are proposed.
The subject of this thesis is the design of axial flow machines. The type of turbomachine under examination is used to supply energy for high viscous fluid flow, as used in mixing and stirring tasks. The high viscous media treated in these tasks usually have non-Newtonian fluid properties. This kind of fluid flow is frequently associated with the field of energy and process engineering.
In order to narrow down the problem described, the field of turbomachinery is restricted to the consideration of propellers. Propellers are used in a wide range of fluid mechanics tasks. In the form of wind turbines, propellers extract kinetic energy from a control room and thereby slow down the flow. Propeller stirrers, on the other hand, increase the energy level of a flow and accelerate it. Both machines are based on the same principle - only the direction of the energy flow is to be considered as the opposite direction.
The design of new agitators is usually based on experience. Often, agitators are, therefore, not flow-optimised, and cannot be optimally operated. In this thesis, it is investigated whether the design processes of modern wind turbines, which are considered to be mature, can be adapted in order to generate a flow-optimised geometry for this type of turbomachine as well.
This thesis will first examine the basics of wind turbine design processes. Special attention will be paid to the differences caused by the viscous fluid properties under consideration. The highly viscous behaviour of the fluids under consideration means that the theoretical fundamentals have to be extended as a result. Such extensions are identified and supplement the theoretical basis. The thesis will then present and examine an analytically based design process for flow-optimised propeller mixers. The procedure is based on blade element momentum theory.
Application of blade element momentum theory requires detailed knowledge of the aerodynamic behaviour of the profiles used. This behaviour is usually only known for low viscosity and high-Re applications, as is usually the case for wind turbines or propeller engines. Comprehensive profile characteristics are not available for highly viscous and low-Re applications. In this thesis, these basics are generated using numerical methods.
In the next step, the newly introduced design method is combined with the results of the investigations of profile aerodynamics for high viscous low-Re fluid flow. This combination is done using a calculation process which produces the flow-optimised geometry of a propeller mixer. The theoretical principles of the methods are implemented in an algorithm in such a way that the resultant turbomachine can be designed for a previously selected operating point, the design point. In contrast to classical turbomachinery, the design point additionally requires the specification of viscous fluid properties.
However, in practical use, the final selected operating point of a turbomachine is often not the design point. The algorithm is examined for its suitability for inverse power calculation as well in order to compute the complete characteristic curve for a previously generated propeller mixer already in the design process.
The fatigue life of metals manufactured via laser-based powder bed fusion (L-PBF) highly
depends on process-induced defects. In this context, not only the size and geometry of the defect, but
also the properties and the microstructure of the surrounding material volume must be considered.
In the presented work, the microstructural changes in the vicinity of a crack-initiating defect in a
fatigue specimen produced via L-PBF and made of AISI 316L were analyzed in detail. Xenon plasma
focused ion beam (Xe-FIB) technique, scanning electron microscopy (SEM), and electron backscatter
diffraction (EBSD) were used to investigate the phase distribution, local misorientations, and grain
structure, including the crystallographic orientations. These analyses revealed a fine grain structure
in the vicinity of the defect, which is arranged in accordance with the melt pool geometry. Besides
pronounced cyclic plastic deformation, a deformation-induced transformation of the initial austenitic
phase into α’-martensite was observed. The plastic deformation as well as the phase transformation
were more pronounced near the border between the defect and the surrounding material volume.
However, the extent of the plastic deformation and the deformation-induced phase transformation
varies locally in this border region. Although a beneficial effect of certain grain orientations on the
phase transformation and plastic deformability was observed, the microstructural changes found
cannot solely be explained by the respective crystallographic orientation. These changes are assumed
to further depend on the inhomogeneous distribution of the multiaxial stresses beneath the defect as
well as the grain morphology
A detailed study of a cylinder activation concept by efficiency loss analysis and 1D simulation
(2020)
Cylinder deactivation is a well-known measure for reducing fuel consumption, especially when applied to gasoline engines. Mostly, such systems are designed to deactivate half of the number of cylinders of the engine. In this study, a new concept is investigated for deactivating only one out of four cylinders of a commercial vehicle diesel engine (“3/4-cylinder concept”). For this purpose, cylinders 2–4 of the engine are operated in “real” 3-cylinder mode, thus with the firing order and ignition distance of a regular 3-cylinder engine, while the first cylinder is only activated near full load, running in parallel to the fourth cylinder. This concept was integrated into a test engine and evaluated on an engine test bench. As the investigations revealed significant improvements for the low-to-medium load region as well as disadvantages for high load, an extensive numerical analysis was carried out based on the experimental results. This included both 1D simulation runs and a detailed cylinder-specific efficiency loss analysis. Based on the results of this analysis, further steps for optimizing the concept were derived and studied by numerical calculations. As a result, it can be concluded that the 3/4-cylinder concept may provide significant improvements of real-world fuel economy when integrated as a drive unit into a tractor.
We present a deterministic simulation scheme for the Boltzmann Semiconductor Equation. The convergence of the method is shown for a simplified space homogeneous case. Numerical experiments, which are very promising, are also given in this situation. The extension for the application to the space inhomogeneous equation with a self consistent electric field is quoted. Theoretical considerations in that case are in preparation.
The direction splitting approach proposed earlier in [6], aiming at the efficient solution of Navier-Stokes equations, is extended and adopted here to solve the Navier-Stokes-Brinkman equations describing incompressible flows in plain and in porous media. The resulting pressure equation is a perturbation of the
incompressibility constrained using a direction-wise factorized operator as proposed in [6]. We prove that this approach is unconditionally stable for the unsteady Navier-Stokes-Brinkman problem. We also provide numerical illustrations of the method's accuracy and efficiency.
Many discrepancy principles are known for choosing the parameter \(\alpha\) in the regularized operator equation \((T^*T+ \alpha I)x_\alpha^\delta = T^*y^\delta\), \(||y-y^d||\leq \delta\), in order to approximate the minimal norm least-squares solution of the operator equation \(Tx=y\). In this paper we consider a class of discrepancy principles for choosing the regularization parameter when \(T^*T\) and \(T^*y^\delta\) are approximated by \(A_n\) and \(z_n^\delta\) respectively with \(A_n\) not necessarily self - adjoint. Thisprocedure generalizes the work of Engl and Neubauer (1985),and particular cases of the results are applicable to the regularized projection method as well as to a degenerate kernel method considered by Groetsch (1990).
A theory of discrete Cosserat rods is formulated in the language of discrete Lagrangian mechanics. By exploiting Kirchho's kinetic analogy, the potential energy density of a rod is a function on the tangent bundle of the conguration manifold and thus formally corresponds to the Lagrangian function of a dynamical system. The equilibrium equations are derived from a variational principle using a formulation that involves null{space matrices. In this formulation, no Lagrange multipliers are necessary to enforce orthonormality of the directors. Noether's theorem relates rst integrals of the equilibrium equations to Lie group actions on the conguration bundle, so{called symmetries. The symmetries relevant for rod mechanics are frame{indierence, isotropy and uniformity. We show that a completely analogous and self{contained theory of discrete rods can be formulated in which the arc{length is a discrete variable ab initio. In this formulation, the potential energy density is dened directly on pairs of points along the arc{length of the rod, in analogy to Veselov's discrete reformulation of Lagrangian mechanics. A discrete version of Noether's theorem then identies exact rst integrals of the discrete equilibrium equations. These exact conservation properties confer the discrete solutions accuracy and robustness, as demonstrated by selected examples of application. Copyright c 2010 John Wiley & Sons, Ltd.
This paper investigates the suitability of the mobile agents approach to the problem of integrating a collection of local DBMS into a single heterogeneous large-scale distributed DBMS. The paper proposes a model of distributed transactions as a set of mobile agents and presents the relevant execution semantics. In addition, the mechanisms which are needed to guarantee the ACID properties in the considered environment are discussed.
In this paper we present an interpreter which allows to support the validation of conceptual models in early stages of the development. We compare hypermedia and expert system approaches to knowledge processing and show how an integrated approach eases the creation of expert systems. Our knowledge engineering tool CoMo-Kit allows a "smooth" transition from initial protocols via a semi-formal specification based on a typed hypertext up to an running expert system. The interpreter uses the intermediate hypertext representation for the interactive solution of problems. Thereby, tasks are distributed to agents via an local area network. This means that the specification of an expert system can directly be used to solve real world problems. If there exist formal (operational) specifications for subtasks then these are delegated to computers. Therefore, our approach allows to specify and validate distributed, cooperative systems where some subtasks are solved by humans and other subtasks are solved automatically by computers.
A practical distributed planning and control system for industrial robots is presented. The hierarchical concept consists of three independent levels. Each level is modularly implemented and supplies an application interface (API) to the next higher level. At the top level, we propose an automatic motion planner. The motion planner is based on a best-first search algorithm and needs no essential off-line computations. At the middle level, we propose a PC-based robot control architecture, which can easily be adapted to any industrial kinematics and application. Based on a client/server-principle, the control unit estab-lishes an open user interface for including application specific programs. At the bottom level, we propose a flexible and modular concept for the integration of the distributed motion control units based on the CAN bus. The concept allows an on-line adaptation of the control parameters according to the robot's configuration. This implies high accuracy for the path execution and improves the overall system performance.
A distributional solution framework is developed for systems consisting of linear hyperbolic partial differential equations (PDEs) and switched differential algebraic equations (DAEs) which are coupled via boundary conditions. The unique solvability is then characterize in terms of a switched delay DAE. The theory is illustrated with an example of electric power lines modeled by the telegraph equations which are coupled via a switching transformer where simulations confirm the predicted impulsive solutions.
For the last decade, optimization of beam orientations in intensitymodulated radiation therapy (IMRT) has been shown to be successful in improving the treatment plan. Unfortunately, the quality of a set of beam orientations depends heavily on its corresponding beam intensity proles. Usually, a stochastic selector is used for optimizing beam orientation, and then a single objective inverse treatment planning algorithm is used for the optimization of beam intensity proles. The overall time needed to solve the inverse planning for every random selection of beam orientations becomes excessive. Recently, considerable improvement has been made in optimizing beam intensity proles by using multiple objective inverse treatment planning. Such an approach results in a variety of beam intensity proles for every selection of beam orientations, making the dependence between beam orientations and its intensity proles less important. We take advantage of this property to present a dynamic algorithm for beam orientation in IMRT which is based on multicriteria inverse planning. The algorithm approximates beam intensity proles iteratively instead of doing it for every selection of beam orientation, saving a considerable amount of calculation time. Every iteration goes from an N-beam plan to a plan with N + 1 beams. Beam selection criteria are based on a score function that minimizes the deviation from the prescribed dose, in addition to a reject-accept criterion. To illustrate the eciency of the algorithm it has been applied to an articial example where optimality is trivial and to three real clinical cases: a prostate carcinoma, a tumor in the head and neck region and a paraspinal tumor. In comparison to the standard equally spaced beam plans, improvements are reported in all of the three clinical examples, even, in some cases with a fewer number of beams.
Medical cyber-physical systems (MCPS) emerged as an evolution of the relations between connected health systems, healthcare providers, and modern medical devices. Such systems combine independent medical devices at runtime in order to render new patient monitoring/control functionalities, such as physiological closed loops for controlling drug infusion or optimization of alarms. Despite the advances regarding alarm precision, healthcare providers still struggle with alarm flooding caused by the limited risk assessment models. Furthermore, these limitations also impose severe barriers on the adoption of automated supervision through autonomous actions, such as safety interlocks for avoiding overdosage. The literature has focused on the verification of safety parameters to assure the safety of treatment at runtime and thus optimize alarms and automated actions. Such solutions have relied on the definition of actuation ranges based on thresholds for a few monitored parameters. Given the very dynamic nature of the relevant context conditions (e.g., the patient’s condition, treatment details, system configurations, etc.), fixed thresholds are a weak means for assessing the current risk. This thesis presents an approach for enabling dynamic risk assessment for cooperative MCPS based on an adaptive Bayesian Networks (BN) model. The main aim of the approach is to support continuous runtime risk assessment of the current situation based on relevant context and system information. The presented approach comprises (i) a dynamic risk analysis constituent, which corresponds to the elicitation of relevant risk parameters, risk metric building, and risk metric management; and (ii) a runtime risk classification constituent, which aims to analyze the current situation risk, establish risk classes, and identify and deploy mitigation measures. The proposed approach was evaluated and its feasibility proved by means of simulated experiments guided by an international team of medical experts with a focus on the requirements of efficacy, efficiency, and availability of patient treatment.
A stereoselective synthesis of isoindolo[2,1-a]quinolin-11(5H)-ones containing three contiguous stereogenic centers is described. This Lewis-acid mediated reaction of enamides with N-aryl-acylimines affords the desired fused heterocyclic isoindolinones in high yields and diastereoselectivities. Scope and limitations of this method are discussed. The stereochemical outcome of this transformation indicates a stepwise reaction pathway.
We derive a new class of particle methods for conservation laws, which are based on numerical flux functions to model the interactions between moving particles. The derivation is similar to that of classical Finite-Volume methods; except that the fixed grid structure in the Finite-Volume method is substituted by so-called mass packets of particles. We give some numerical results on a shock wave solution for Burgers equation as well as the well-known one-dimensional shock tube problem.
Compared to conventional techniques in computational fluid dynamics, the lattice Boltzmann method (LBM) seems to be a completely different approach to solve the incompressible Navier-Stokes equations. The aim of this article is to correct this impression by showing the close relation of LBM to two standard methods: relaxation schemes and explicit finite difference discretizations. As a side effect, new starting points for a discretization of the incompressible Navier-Stokes equations are obtained.
A single facility problem in the plane is considered, where an optimal location has to be
identified for each of finitely many time-steps with respect to time-dependent weights and
demand points. It is shown that the median objective can be reduced to a special case of the
static multifacility median problem such that results from the latter can be used to tackle the
dynamic location problem. When using block norms as distance measure between facilities,
a Finite Dominating Set (FDS) is derived. For the special case with only two time-steps, the
resulting algorithm is analyzed with respect to its worst-case complexity. Due to the relation
between dynamic location problems for T time periods and T-facility problems, this algorithm
can also be applied to the static 2-facility location problem.
This work deals with the simulation of the micro-cutting process of titanium. For this
purpose, a suitable crystal-plastic material model is developed and efficient implemen-
tations are investigated to simulate the micro-cutting process. Several challenges arise
for the material model. On the one hand, the low symmetry hexagonal close-packed
crystal structure of titanium has to be considered. On the other hand, large defor-
mations and strains occur during the machining process. Another important part is
the algorithm for the determination of the active slip systems, which has a significant
influence on the stability of the simulation. In order to obtain a robust implemen-
tation, different aspects, such as the algorithm for the determination of the active
slip systems, the method for mesh separation between chip and workpiece as well as
the hardening process are investigated, and different approaches are compared. The
developed crystal-plastic material model and the selected implementations are first
validated and investigated using illustrative examples. The presented simulations of
the micro-cutting process show the influence of different machining parameters on the
process. Finally, the influence of a real microstructure on the plastic deformation and
the cutting force during the process is shown.
Information technology support for complex, dynamic, and distributed business processes as they occur in engineering domains requires an advanced process management system which enhances currently available workflow management services with respect to integration, flexibility, and adapt ation. We present an uniform and flexible framework for advanced process management on an a bstract level which uses and adapts agent technology from distributed artificial intelligence for both modelling and enacting of processes. We identify two different frameworks for applying agent tec hnology to process management: First, as a multi-agent system with the domain of process manag ement. Second, as a key infrastructure technology for building a process management system. We will then follow the latter approach and introduce different agent types for managing activities, products, and resources which capture specific views on the process.
In continous location problems we are given a set of existing facilities and we are looking for the location of one or several new facilities. In the classical approaches weights are assigned to existing facilities expressing the importance of the new facilities for the existing ones. In this paper, we consider a pointwise defined objective function where the weights are assigned to the existing facilities depending on the location of the new facility. This approach is shown to be a generalization of the median, center and centdian objective functions. In addition, this approach allows to formulate completely new location models. Efficient algorithms as well as structure results for this algebraic approach for location problems are presented. Extensions to the multifacility and restricted case are also considered.
We propose a model for glioma patterns in a microlocal tumor environment under
the influence of acidity, angiogenesis, and tissue anisotropy. The bottom-up model deduction
eventually leads to a system of reaction–diffusion–taxis equations for glioma and endothelial cell
population densities, of which the former infers flux limitation both in the self-diffusion and taxis
terms. The model extends a recently introduced (Kumar, Li and Surulescu, 2020) description of
glioma pseudopalisade formation with the aim of studying the effect of hypoxia-induced tumor
vascularization on the establishment and maintenance of these histological patterns which are typical
for high-grade brain cancer. Numerical simulations of the population level dynamics are performed
to investigate several model scenarios containing this and further effects.
Estelle is an internationally standardized formal description technique (FDT) designed for the specification of distributed systems, in particular communication protocols. An Estelle specification describes a system of communicating components (module instances). The specified system is closed in a topological sense, i.e. it has no ability to interact with some environment. Because of this restriction, open systems can only be specified together with and incorporated with an environment. To overcome this restriction, we introduce a compatible extension of Estelle, called "Open Estelle". It allows the specification of (topologically) open systems, i.e. systems that have the ability to communicate with any environment through a well-defined external interface. We define aformal syntax and a formal semantics for Open Estelle, both based on and extending the syntax and semantics of Estelle. The extension is compatible syntactically and semantically, i.e. Estelle is a subset of Open Estelle. In particular, the formal semantics of Open Estelle reduces to the Estelle semantics in the special case of a closed system. Furthermore, we present a tool for the textual integration of open systems into environments specified in Open Estelle, and a compiler for the automatic generation of implementations directly from Open Estelle specifications.
This paper describes the architecture and concept of operation of a Framework for Adaptive Process Modeling and Execution (FAME). The research addresses the absence of robust methods for supporting the software process management life cycle. FAME employs a novel, model-based approach in providing automated support for different activities in the software development life cycle including project definition, process design, process analysis, process enactment, process execution status monitoring, and execution status-triggered process redesign. FAME applications extend beyond the software development domain to areas such as agile manufacturing, project management, logistics planning, and business process reengineering.
This research for this thesis was conducted to develop a framework which supports the automatic configuration of project-specific software development processes by selecting and combining different technologies: the Process Configuration Framework. The research draws attention to the problem that while the research community develops new technologies, the industrial companies continue only using their well-known ones. Because of this, technology transfer takes decades. In addition, there is the fact that there is no solution which solves all problems in a software development project. This leads to a number of technologies which need to be combined for one project.
The framework developed and explained in this research mainly addresses those problems by building a bridge between research and industry as well as by supporting software companies during the selection of the most appropriate technologies combined in a software process. The technology transformation gap is filled by a repository of (new) technologies which are used as a foundation of the Process Configuration Framework. The process is configured by providing SPEM process pattern for each technology, so that the companies can build their process by plugging into each other.
The technologies of the repository were specified in a schema including a technology model, context model, and an impact model. With context and impact it is possible to provide information about a technology, for example, its benefits to quality, cost or schedule. The offering of the process pattern as output of the Process Configuration Framework is performed in several stages:
I Technology Ranking:
1 Ranking based on Application Domain, Project & Impact
2 Ranking based on Environment
3 Ranking based on Static Context
II Technology Combination:
4 Creation of all possible Technology Chains
5 Restriction of the Technology Chains
6 Ranking based on Static and Dynamic Context
7 Extension of the Chains by Quality Assurance
III Process Configuration:
8 Process Component Diagram
9 Extension of the Process Component Diagram
10 Instantiation of the Components by Technologies of the Technology Chain
11 Providing process patterns
12 Creation of the process based on Patterns
The effectiveness and quality of the Process Configuration Framework have additionally been evaluated in a case study. Here, the Technology Chains manually created by experts were compared to the chains automatically created by the framework after it was configured by those experts. This comparison depicted that the framework results are similar and therefore can be used as a recommendation.
We conclude from our research that support during the configuration of a process for software projects is important especially for non-experts. This support is provided by the Process Configuration Framework developed in this research. In addition our research has shown that this framework offers a possibility to speed up the technology transformation gap between the research community and industrial companies.
We develop a framework for shape optimization problems under state equation con-
straints where both state and control are discretized by B-splines or NURBS. In other
words, we use isogeometric analysis (IGA) for solving the partial differential equation and a nodal approach to change domains where control points take the place of nodes and where thus a quite general class of functions for representing optimal shapes and their boundaries becomes available. The minimization problem is solved by a gradient descent method where the shape gradient will be defined in isogeometric terms. This
gradient is obtained following two schemes, optimize first–discretize then and, reversely,
discretize first–optimize then. We show that for isogeometric analysis, the two schemes yield the same discrete system. Moreover, we also formulate shape optimization with respect to NURBS in the optimize first ansatz which amounts to finding optimal control points and weights simultaneously. Numerical tests illustrate the theory.
A prime motivation for using XML to directly represent pieces of information is the ability of supporting ad-hoc or 'schema-later' settings. In such scenarios, modeling data under loose data constraints is essential. Of course, the flexibility of XML comes at a price: the absence of a rigid, regular, and homogeneous structure makes many aspects of data management more challenging. Such malleable data formats can also lead to severe information quality problems, because the risk of storing inconsistent and incorrect data is greatly increased. A prominent example of such problems is the appearance of the so-called fuzzy duplicates, i.e., multiple and non-identical representations of a real-world entity. Similarity joins correlating XML document fragments that are similar can be used as core operators to support the identification of fuzzy duplicates. However, similarity assessment is especially difficult on XML datasets because structure, besides textual information, may exhibit variations in document fragments representing the same real-world entity. Moreover, similarity computation is substantially more expensive for tree-structured objects and, thus, is a serious performance concern. This thesis describes the design and implementation of an effective, flexible, and high-performance XML-based similarity join framework. As main contributions, we present novel structure-conscious similarity functions for XML trees - either considering XML structure in isolation or combined with textual information -, mechanisms to support the selection of relevant information from XML trees and organization of this information into a suitable format for similarity calculation, and efficient algorithms for large-scale identification of similar, set-represented objects. Finally, we validate the applicability of our techniques by integrating our framework into a native XML database management system; in this context we address several issues around the integration of similarity operations into traditional database architectures.
Facility Location Problems are concerned with the optimal location of one or several new facilities, with respect to a set of existing ones. The objectives involve the distance between new and existing facilities, usually a weighted sum or weighted maximum. Since the various stakeholders (decision makers) will have different opinions of the importance of the existing facilities, a multicriteria problem with several sets of weights, and thus several objectives, arises. In our approach, we assume the decision makers to make only fuzzy comparisons of the different existing facilities. A geometric mean method is used to obtain the fuzzy weights for each facility and each decision maker. The resulting multicriteria facility location problem is solved using fuzzy techniques again. We prove that the final compromise solution is weakly Pareto optimal and Pareto optimal, if it is unique, or under certain assumptions on the estimates of the Nadir point. A numerical example is considered to illustrate the methodology.
A General Hilbert Space Approach to Wavelets and Its Application in Geopotential Determination
(1999)
A general approach to wavelets is presented within a framework of a separable functional Hilbert space H. Basic tool is the construction of H-product kernels by use of Fourier analysis with respect to an orthonormal basis in H. Scaling function and wavelet are defined in terms of H-product kernels. Wavelets are shown to be 'building blocks' that decorrelate the data. A pyramid scheme provides fast computation. Finally, the determination of the earth's gravitational potential from single and multipole expressions is organized as an example of wavelet approximation in Hilbert space structure.
We present a generalization of Proth's theorem for testing certain large integers for primality. The use of Gauß sums leads to a much simpler approach to these primality criteria as compared to the earlier tests. The running time of the algorithms is bounded by a polynomial in the length of the input string. The applicability of our algorithms is linked to certain diophantine approximations of \(l\)-adic roots of unity.
We present an entropy concept measuring quantum localization in dynamical systems based on time averaged probability densities. The suggested entropy concept is a generalization of a recently introduced [PRL 75, 326 (1995)] phase-space entropy to any representation chosen according to the system and the physical question under consideration. In this paper we inspect the main characteristics of the entropy and the relation to other measures of localization. In particular the classical correspondence is discussed and the statistical properties are evaluated within the framework of random vector theory. In this way we show that the suggested entropy is a suitable method to detect quantum localization phenomena in dynamical systems.