Refine
Year of publication
Document Type
- Doctoral Thesis (1877)
- Preprint (1186)
- Article (735)
- Report (486)
- Periodical Part (296)
- Master's Thesis (255)
- Working Paper (115)
- Conference Proceeding (47)
- Diploma Thesis (35)
- Lecture (25)
Language
- English (3173)
- German (1993)
- Multiple languages (6)
- Spanish (4)
Keywords
- AG-RESY (64)
- PARO (31)
- Stadtplanung (30)
- Erwachsenenbildung (29)
- Organisationsentwicklung (28)
- Schule (26)
- Simulation (25)
- Modellierung (24)
- Mathematische Modellierung (21)
- Visualisierung (21)
Faculty / Organisational entity
- Kaiserslautern - Fachbereich Mathematik (1184)
- Kaiserslautern - Fachbereich Informatik (928)
- Kaiserslautern - Fachbereich Maschinenbau und Verfahrenstechnik (588)
- Kaiserslautern - Fachbereich Chemie (433)
- Kaiserslautern - Fachbereich Sozialwissenschaften (351)
- Kaiserslautern - Fachbereich Physik (334)
- Fraunhofer (ITWM) (224)
- Kaiserslautern - Fachbereich Biologie (187)
- Kaiserslautern - Fachbereich Elektrotechnik und Informationstechnik (171)
- Distance and Independent Studies Center (DISC) (168)
This research explores the development of web based reference software for
characterisation of surface roughness for two-dimensional surface data. The reference software used for verification of surface characteristics makes the evaluation methods easier for clients. The algorithms used in this software
are based on International ISO standards. Most software used in industrial measuring
instruments may give variations in the parameters calculated due to numerical changes in
calculation. Such variations can be verified using the proposed reference software.
The evaluation of surface roughness is carried out in four major steps: data capture, data
align, data filtering and parameter calculation. This work walks through each of these steps
explaining how surface profiles are evaluated by pre-processing steps called fitting and
filtering. The analysis process is then followed by parameter evaluation according to DIN EN
ISO 4287 and DIN EN ISO 13565-2 standards to extract important information from the
profile to characterise surface roughness.
If gradient based derivative algorithms are used to improve industrial products by reducing their target functions, the derivatives need to be exact.
The last percent of possible improvement, like the efficiency of a turbine, can only be gained if the derivatives are consistent with the solution process that is used in the simulation software.
It is problematic that the development of the simulation software is an ongoing process which leads to the use of approximated derivatives.
If a derivative computation is implemented manually, it will be inconsistent after some time if it is not updated.
This thesis presents a generalized approach which differentiates the whole simulation software with Algorithmic Differentiation (AD), and guarantees a correct and consistent derivative computation after each change to the software.
For this purpose, the variable tagging technique is developed.
The technique checks at run-time if all dependencies, which are used by the derivative algorithms, are correct.
Since it is also necessary to check the correctness of the implementation, a theorem is developed which describes how AD derivatives can be compared.
This theorem is used to develop further methods that can detect and correct errors.
All methods are designed such that they can be applied in real world applications and are used within industrial configurations.
The process described above yields consistent and correct derivatives but the efficiency can still be improved.
This is done by deriving new derivative algorithms.
A fixed-point iterator approach, with a consistent derivation, yields all state of the art algorithms and produces two new algorithms.
These two new algorithms include all implementation details and therefore they produce consistent derivative results.
For detecting hot spots in the application, the state of the art techniques are presented and extended.
The data management is changed such that the performance of the software is affected only marginally when quantities, like the number of input and output variables or the memory consumption, are computed for the detection.
The hot spots can be treated with techniques like checkpointing or preaccumulation.
How these techniques change the time and memory consumption is analyzed and it is shown how they need to be used in selected AD tools.
As a last step, the used AD tools are analyzed in more detail.
The major implementation strategies for operator overloading AD tools are presented and implementation improvements for existing AD tools are discussed.
The discussion focuses on a minimal memory consumption and makes it possible to compare AD tools on a theoretical level.
The new AD tool CoDiPack is based on these findings and its design and concepts are presented.
The improvements and findings in this thesis make it possible, that an automatic, consistent and correct derivative is generated in an efficient way for industrial applications.
Mobility has become an integral feature of many wireless networks. Along with this mobility comes the need for location awareness. A prime example for this development are today’s and future transportation systems. They increasingly rely on wireless communications to exchange location and velocity information for a multitude of functions and applications. At the same time, the technological progress facilitates the widespread availability of sophisticated radio technology such as software-defined radios. The result is a variety of new attack vectors threatening the integrity of location information in mobile networks.
Although such attacks can have severe consequences in safety-critical environments such as transportation, the combination of mobility and integrity of spatial information has not received much attention in security research in the past. In this thesis we aim to fill this gap by providing adequate methods to protect the integrity of location and velocity information in the presence of mobility. Based on physical effects of mobility on wireless communications, we develop new methods to securely verify locations, sequences of locations, and velocity information provided by untrusted nodes. The results of our analyses show that mobility can in fact be exploited to provide robust security at low cost.
To further investigate the applicability of our schemes to real-world transportation systems, we have built the OpenSky Network, a sensor network which collects air traffic control communication data for scientific applications. The network uses crowdsourcing and has already achieved coverage in most parts of the world with more than 1000 sensors.
Based on the data provided by the network and measurements with commercial off-the-shelf hardware, we demonstrate the technical feasibility and security of our schemes in the air traffic scenario. Moreover, the experience and data provided by the OpenSky Network allows us to investigate the challenges for our schemes in the real-world air traffic communication environment. We show that our verification methods match all
requirements to help secure the next generation air traffic system.
Road accidents remain as one of the major causes of death and injuries globally. Several million people die every year due to road accidents all over the world. Although the number of accidents in European region have reduced in the past years, road safety still remains a major challenge. Especially in case of commercial trucks, due to the size and load of the vehicle, even minor collisions with other road users would lead to serious injuries or death. In order to reduce number of accidents, automotive industry is rapidly developing advanced driver assistance systems (ADAS) and automated driving technologies. Efficient and reliable solutions are required for these systems to sense, perceive and react to different environmental conditions. For vehicle safety applications such as collision avoidance with vulnerable road users (VRUs), it is not only important for the system to efficiently detect and track the objects in the vicinity of the vehicle but should also function robustly.
An environment perception solution for application in commercial truck safety systems and for future automated driving is developed in this work. Thereby a method for integrated tracking and classification of road users in the near vicinity of the vehicle is formulated. The drawbacks in conventional multi-object tracking algorithms with respect to state, measurement and data association uncertainties have been addressed with the recent advancements in the field of unified multi-object tracking solutions based on random finite sets (RFS). Gaussian mixture implementation of the recently developed labeled multi-Bernoulli (LMB) filter [RSD15] is used as the basis for multi-object tracking in this work. Measurement from an high-resolution radar sensor is used as the main input for detecting and tracking objects.
On one side, the focus of this work is on tracking VRUs in the near vicinity of the truck. As it is beneficial for most of the vehicle safety systems to also know the category that the object belongs to, the focus on the other side is also to classify the road users. All the radar detections believed to originate from a single object are clustered together with help of density based spatial clustering for application with noise (DBSCAN) algorithm. Each cluster of detections would have different properties based on the respective object characteristics. Sixteen distinct features based on radar detections, that are suitable for separating pedestrians, bicyclists and passenger car categories are selected and extracted for each of the cluster. A machine learning based classifier is constructed, trained and parameterised for distinguishing the road users based on the extracted features.
The class information derived from the radar detections can further be used by the tracking algorithm, to adapt the model parameters used for precisely predicting the object motion according to the category of the object. Multiple model labeled multi-Bernoulli filter (MMLMB) is used for modelling different object motions. Apart from the detection level, the estimated state of an object on the tracking level also provides information about the object class. Both these informations are fused using Dempster-Shafer theory (DST) of evidence, based on respective class probabilities Thereby, the output of the integrated tracking and classification with MMLMB filter are classified tracks that can be used by truck safety applications with better reliability.
The developed environment perception method is further implemented as a real-time prototypical system on a commercial truck. The performance of the tracking and classification approaches are evaluated with the help of simulation and multiple test scenarios. A comparison of the developed approaches to a conventional converted measurements Kalman filter with global nearest neighbour association (CMKF-GNN) shows significant advantages in the overall accuracy and performance.
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.
Cyanobacteria of biological soil crusts (BSCs) represent an important part of circumpolar
and Alpine ecosystems, serve as indicators for ecological condition and climate
change, and function as ecosystem engineers by soil stabilization or carbon and nitrogen
input. The characterization of cyanobacteria from both polar regions remains
extremely important to understand geographic distribution patterns and community
compositions. This study is the first of its kind revealing the efficiency of combining
denaturing gradient gel electrophoresis (DGGE), light microscopy and culture-based
16S rRNA gene sequencing, applied to polar and Alpine cyanobacteria dominated
BSCs. This study aimed to show the living proportion of cyanobacteria as an extension
to previously published meta-transcriptome
data of the same study sites.
Molecular fingerprints showed a distinct clustering of cyanobacterial communities
with a close relationship between Arctic and Alpine populations, which differed from
those found in Antarctica. Species richness and diversity supported these results,
which were also confirmed by microscopic investigations of living cyanobacteria
from the BSCs. Isolate-based
sequencing corroborated these trends as cold biome
clades were assigned, which included a potentially new Arctic clade of Oculatella.
Thus, our results contribute to the debate regarding biogeography of cyanobacteria
of cold biomes.
Increasing costs due to the rising attrition of drug candidates in late developmental phases alongside post-marketing withdrawal of drugs challenge the pharmaceutical industry to further improve their current preclinical safety assessment strategies. One of the most common reasons for the termination of drug candidates is drug induced hepatotoxicity, which more often than not remains undetected in early developmental stages, thus emphasizing the necessity for improved and more predictive preclinical test systems. One reason for the very limited value of currently applied in vitro test systems for the detection of potential hepatotoxic liabilities is the lack of organotypic and tissue-specific physiology of hepatocytes cultured in ordinary monolayer culture formats.
The thesis at hand primarily deals with the evaluation of both two- and three-dimensional cell culture approaches with respect to their relative ability to predict the hepatotoxic potential of drug candidates in early developmental phases. First, different hepatic cell models, which are routinely used in pharmaceutical industry (primary human hepatocytes as well as the three cell lines HepG2, HepaRG and Upcyte hepatocytes), were investigated in conventional 2D monolayer culture with respect to their ability to detect hepatotoxic effects in simple cytotoxicity studies. Moreover, it could be shown that the global protein expression levels of all cell lines substantially differ from that of primary human hepatocytes, with the least pronounced difference in HepaRG cells.
The introduction of a third dimension through the cultivation of spheroids enables hepatocytes to recapitulate their typical native polarity and furthermore dramatically increases the contact surface of adjacent cells. These differences in cellular architecture have a positive influence on hepatocyte longevity and the expression of drug metabolizing enzymes and transporters, which could be proven via immunofluorescent (IF) staining for at least 14 days in PHH and at least 28 days in HepaRG spheroids, respectively. Additionally, the IF staining of three different phase III transporters (MDR1, MRP2 and BSEP) indicated a bile canalicular network in spheroids of both cell models. A dose-dependent inducibility of important cytochrome P450 isoenzymes in HepaRG spheroids could be shown on the protein level via IF for at least 14 days. CYP inducibility of HepaRG cells cultured in 2D and 3D was compared on the mRNA level for up to 14 days and inducibility was generally lower in 3D compared to 2D under the conditions of this study. In a comparative cytotoxicity study, both PHH and HepaRG spheroids as well as HepaRG monolayers have been treated with five hepatotoxic drugs for up to 14 days and viability was measured at three time points (days 3, 7 and 14). A clear time- and dose-dependent onset of the drug-induced hepatotoxic effects was observable in all conditions tested, indicated by a shift of the respective EC50 value towards lower doses by increasing exposure. The observed effects were most pronounced in PHH spheroids, thus indicating those as the most sensitive cell model in this study. Moreover, HepaRG cells were more sensitive in spheroid culture compared to monolayers, which suggests a potential application of spheroids as long-term test system for the detection of hepatotoxicities with slow onset. Finally, the basal protein expression levels of three antigens (CYP1A2, CYP3A4 and NAT 1/2) were analyzed via Western Blotting in HepaRG cells cultured in three different cell culture formats (2D, 3D and QV) in order to estimate the impact of the cell culture conditions on protein expression levels. In the QV system enables a pump-driven flow of cell culture media, which introduces both mechanical stimuli through shear and molecular stimuli through dynamic circulation to the monolayer. Those stimuli resulted in a clearly positive effect on the expression levels of the selected antigens by an increased expression level in comparison to both 2D and 3D. In contrast, HepaRG spheroids showed time-dependent differences with the overall highest levels at day 7.
The studies presented in this thesis delivered valuable information on the increased physiological relevance in dependence on the cell culture format: three-dimensionality as well as the circulation of media lead to a more differentiated phenotype in hepatic cell models. Those cell culture formats are applicable in preclinical drug development in order to obtain more relevant information at early developmental stages and thus help to create a more efficient drug development process. Nonetheless, further studies are necessary to thoroughly characterize, validate and standardize such novel cell culture approaches prior to their routine application in industry.
In Rheinland-Pfalz hinterlässt der demografische Wandel insbesondere in den ländlichen Regionen seine Spuren und die Gesellschaft wird „älter, bunter, weniger“. Ministerpräsidentin Malu Dreyer verdeutlichte bereits in ihrer Regierungserklärung 2013, dass auch die Förderpolitik des Landes neu ausgerichtet werden muss, um den Herausforderungen des demografischen Wandels frühzeitig begegnen zu können. Dabei sind die stärkere Zusammenarbeit der Kommunen sowie die gemeinsame Erarbeitung von überörtlichen Entwicklungskonzepten notwendig, um den gemeinsamen Bedürfnissen Rechnung tragen zu können. Die Entwicklungskonzepte sollen auf Basis von moderierten Beteiligungsprozessen entstehen, da die Bürgerinnen und Bürger am besten wissen, wie sich die Bedarfe in einer Region aufgrund des demografischen Wandels ändern.
In diesem Zusammenhang startete das Land Rheinland-Pfalz im Jahr 2013 die Zukunftsinitiative „Starke Kommunen – Starkes Land“, welche ein 30-monatiges landesweites Beratungs- und Begleitprojekt darstellte. Der Wettbewerb im Jahr 2013 richtete sich an die Verbandsgemeinden und verbandsfreien Gemeinden in Rheinland-Pfalz, an dessen Ende sechs Modellräume ausgewählt wurden. In diesen wurden Möglichkeiten von Bürgerbeteiligungen und langfristiger interkommunaler Zusammenarbeit auf Verbandsgemeinde-Ebene erprobt und ausgewertet.
Prof. Steinebach und das Team begleiteten die Zukunftsinitiative wissenschaftlich. Der Aufgabenbereich umfasste dabei die Evaluierung der organisatorischen Struktur und des Projektaufbaus, die Analyse der inhaltlichen Themenfelder sowie die Untersuchung und Bewertung der interkommunalen Kooperation. Am Ende der wissenschaftlichen Begleitung wurden die Ergebnisse aufgearbeitet und Handlungsempfehlungen gegeben. Daraus sollen Rückschlüsse für die Förderpolitik des Landes gezogen werden.
Im Zeitraum von März bis Mai 2017 wurde eine Evaluierung der Zukunftsinitiative durchgeführt. Diese ist im Download enthalten.
This thesis consists of five chapters. Chapter one elaborates on the principle of cognitive consistency and provides an overview of what extant research refers to as cognitive consistency theories (e.g., Abelson et al., 1968; Harmon-Jones & Harmon-Jones, 2007; Simon, Stenstrom, & Read, 2015). Moreover, it describes the most prominent theoretical representatives in this context, namely balance theory (Heider, 1946, 1958), congruity theory (Osgood & Tannenbaum, 1955), and cognitive dissonance theory (Festinger, 1957). Chapter one further outlines the role of individuals’ preference for cognitive consistency in the context of financial resource acquisition, the recruitment of employees and the acquisition of customers in the entrepreneurial context.
Chapter two is co-authored by Prof. Dr. Matthias Baum and presents two separate studies in which we empirically investigate the hypothesis that social entrepreneurs face a systematic disadvantage, compared to for-profit entrepreneurs, when seeking to acquire financial resources. Further, our work goes beyond existing research by introducing biased perceptions as a factor that may constrain social enterprise resource acquisition and therefore possibly stall the process of social value creation. On the foundation of role congruity theory (Eagly & Karau, 2002), we emphasize on the question whether social entrepreneurs provide signals which are less congruent with the stereotype of successful entrepreneurs and, in such, are perceived as less competent. We further test whether such biased competency perceptions feed forward into a lower probability to receive funding.
Chapter three is also co-authored by Prof. Dr. Matthias Baum as well as by Eva Henrich. The aim of this chapter is to further our understanding of the early recruitment phase and to contribute to the current debate about how firms should orchestrate their recruitment channels in order to enhance the creation of employer knowledge. We introduce the concept of integrated marketing communication into the recruitment field and examine how the level of consistency regarding job or organization information affects the recall and the recognition of that information. We additionally test whether information consistency among multiple recruitment channels influences information recognition failure quota. Answering this question is important as by failing to remember the source of recruitment information, job seekers may attribute job information to the wrong firm and thus create an incorrect employer knowledge.
Chapter four, which is co-authored by Prof. Dr. Matthias Baum, introduces customer congruity perceptions between a brand and a reward in the context of customer referral programs as an essential driver of the effectiveness of such programs. More precisely, we posit and empirically test a model according to which the decision-making process of the customer recommending a firm involves multiple mental steps and assumes reward perceptions to be an immediate antecedent of brand evaluation, which then, ultimately shapes the likelihood of recommendation. The level of congruity/incongruity is set up as an antecedent state and affects the perceived attractiveness of the reward. Our work contributes to the discussion on the optimal level of congruity between a prevailing schema in the mind of the customer and a stimulus presented. In addition, chapter four introduces customer referral programs as a strategic tool for brand managers. Chapter four is further published in Psychology & Marketing.
Chapter five first proposes that marketing strategies specifically designed to induce word-of-mouth (WOM) behavior are particular relevant for new ventures. Against the background that previous research suggests that customer perceptions of young firm age may influence customer behavior and the degree to which customers support new ventures (e.g., Choi & Shepherd, 2005; Stinchcombe, 1965), we secondly conduct an experiment to examine the causal mechanisms linking firm age and customer WOM. Chapter five, too, is co-authored by Prof. Dr. Matthias Baum.
Berufliche Umbrüche sind Teil der Entwicklung eines Menschen. Sie berühren auch seine Persönlichkeit und seine Identität. Wann kann man von gelingender Identitätsentwicklung sprechen? Woran lässt sich diese festmachen? Kann berufsbiografische Diskontinuität einen gelingenden Beitrag zur Identitätsentwicklung darstellen? Und wenn ja, wie? Was bedeutet es, berufliche Umbrüche nicht nur anzunehmen, sondern auch zu gestalten, damit sie einen positiven Beitrag zur Identitätsentwicklung leisten? Welche Faktoren sind dafür förderlich? Und wie sollten diese Erkenntnisse in der erwachsenenbildnerischen Praxis berücksichtigt werden? Die Arbeit nimmt zunächst den Begriff der Identität in den Blick und wendet sich besonders dem Begriff der Anerkennung zu. Nach Betrachtungen zum Zusammenhang von Identität und Erwerbsarbeit sowie einem Überblick über die Phasen von Erwerbsbiografien werden erwachsenenpädagogische Überlegungen angestellt, die für Transitionsprozesse benötigte Kompetenzen ins Zentrum stellen und Konsequenzen für die Arbeit in Einrichtungen der Erwachsenenbildung darstellen.
Im Fokus dieser Promotionsarbeit stand die Synthese neuer kationischer Eisenkomplexe, die
sowohl einen Cyclopentadienyl-, als auch einen Phenylliganden besitzen. Der Sechsringligand
wurde dabei mit stickstoff- oder phosphorhaltigen Substituenten funktionalisiert. Dabei konnten
erstmals Eisenarenkomplexe mit Azidobenzolliganden isoliert und charakterisiert werden. Die
Umsetzung mit heterocyclischen Nucleophilen zeigte bei den 1,2,3-Triazolen die Möglichkeit in
1- und 2-Position eine Bindungsknüpfung einzugehen. Dies konnte durch die Verwendung von
Imidazolidsalzen umgangen werden und so konnte eine Reihe mono- und disubstituierter
Eisenkomplexe mit Methylimidazol und Benzimidazol synthetisiert werden. Durch Alkylierung und
Benzylierung gelang auf diesem Weg der Zugang zu di- und trikationischen Eisenarenkomplexen,
welche die Vorstufe zu NHC-Komplexen bilden. Für die Funktionalisierung mit phosphorhaltigen
Gruppen konnte ein Syntheseweg erarbeitet und auf disubstituierte Komplexe übertragen werden.
Es gelang durch die Koordination von Gold einen kationischen heterobimetallischen Komplex zu
synthetisieren und vollständig zu charakterisieren. Dieser zeigte in mehreren
Cyclisierungsreaktionen hohe katalytische Aktivität, welche über der literaturbekannter
Katalysatoren lag. Mitunter konnten vergleichbare Umsätze unter milderen Bedingungen erzielt
werden.
The transfer of substrates between to enzymes within a biosynthesis pathway is an effective way to synthesize the specific product and a good way to avoid metabolic interference. This process is called metabolic channeling and it describes the (in-)direct transfer of an intermediate molecule between the active sites of two enzymes. By forming multi-enzyme cascades the efficiency of product formation and the flux is elevated and intermediate products are transferred and converted in a correct manner by the enzymes.
During tetrapyrrole biosynthesis several substrate transfer events occur and are prerequisite for an optimal pigment synthesis. In this project the metabolic channeling process during the pink pigment phycoerythrobilin (PEB) was investigated. The responsible ferredoxin-dependent bilin reductases (FDBR) for PEB formation are PebA and PebB. During the pigment synthesis the intermediate molecule 15,16-dihydrobiliverdin (DHBV) is formed and transferred from PebA to PebB. While in earlier studies a metabolic channeling of DHBV was postulated, this work revealed new insights into the requirements of this protein-protein interaction. It became clear, that the most important requirement for the PebA/PebB interaction is based on the affinity to their substrate/product DHBV. The already high affinity of both enzymes to each other is enhanced in the presence of DHBV in the binding pocket of PebA which leads to a rapid transfer to the subsequent enzyme PebB. DHBV is a labile molecule and needs to be rapidly channeled in order to get correctly further reduced to PEB. Fluorescence titration experiments and transfer assays confirmed the enhancement effect of DHBV for its own transfer.
More insights became clear by creating an active fusion protein of PebA and PebB and comparing its reaction mechanism with standard FDBRs. This fusion protein was able to convert biliverdin IXα (BV IXα) to PEB similar to the PebS activity, which also can convert BV IXα via DHBV to PEB as a single enzyme. The product and intermediate of the reaction were identified via HPLC and UV-Vis spectroscopy.
The results of this work revealed that PebA and PebB interact via a proximity channeling process where the intermediate DHBV plays an important role for the interaction. It also highlights the importance of substrate channeling in the synthesis of PEB to optimize the flux of intermediates through this metabolic pathway.
Eine Anpassung von Wasserversorgungs- und Abwasserentsorgungssystemen im ländlichen Raum kann aufgrund vielfältiger Herausforderungen wie demografischen, siedlungsstrukturellen und klimatischen Veränderungen erforderlich werden. Im Zuge dessen können auch die Nachhaltigkeit und Ressourceneffizienz der bestehenden Systeme gesteigert werden. Das Ziel dieser Arbeit ist die Ableitung von Handlungsempfehlungen zur Unterstützung der notwendigen Anpassungsprozesse der Abwasserentsorgung ländlicher Gemeinden. Dazu werden verschiedene Transformationspfade für Abwassersysteme aufgezeigt und analysiert.
In dieser Arbeit wird ein softwaregestütztes Entscheidungs- und Optimierungssystem angewendet und evaluiert, dass optimale Anpassungsmöglichkeiten aufgezeigt. Das gemischt-ganzzahlige lineare Optimierungsmodell berechnet für jede Gemeinde in Abhängigkeit von dem ausgewählten Szenario und vorgegebenen Zielen den optimalen Transformationspfad mit seiner zeitlichen und räumlichen Umsetzung. In den Szenarien werden zukünftige Entwicklungen der Bevölkerung, der Siedlungsstruktur, des Wasserbedarfs, der Kosten technischer Anlagen und des Klimawandels berücksichtigt. Die Zielfunktion bildet sich aus der gewichteten Summe ökonomischer, ökologischer und sozialer Bewertungskriterien. Die beispielhafte Anwendung des Modells erfolgt für zwei repräsentative ländliche Modellkommunen in Rheinland-Pfalz.
Durch eine detaillierte Auswertung und Evaluierung von ausgewählten Kombinationen von Szenarien und Bewertungskriterien kann das Spektrum an möglichen Transformationspfaden von der Erhaltung des zentralen Systems bis hin zu dezentralen und ressourcenorientierten Systemen aufgezeigt werden. Sensitivitätsbetrachtungen zeigen, dass die Auswahl und Gewichtung der Bewertungskriterien und die lokalen Randbedingungen der Gemeinde einen größeren Einfluss auf die resultierende Transformationspfade haben als die Auswahl der Szenarien.
Der Zustand des Entwässerungssystems wie der Anteil alter Kanäle, ein großer Anteil Mischsystem, große Durchmesser und eine große Kanallänge pro Einwohner sowie eine niedrige Siedlungsdichte fördern dezentrale Strukturen und sind geeignete Voraussetzungen für einen Systemwechsel. Bei der Priorisierung der Ziele Flexibilität, Wasserbilanz und Wasserrecycling wird die Dezentralisierung eines Systems mit Kleinkläranlagen favorisiert. Ein ressourcenorientiertes System mit einer Grau- und Schwarzwassertrennung ist nur zukünftig vorteilhaft, wenn die Ziele Wasserrecycling, Nährstoffrecycling und/oder Energieeffizienz priorisiert werden. Wenn ein Systemwechsel vollzogen werden soll, müssen auch die Auswirkungen auf die Wasserversorgung und Abwasserreinigung untersucht werden.
Es kann gezeigt werden, dass bei einer abnehmenden Bevölkerung dezentrale und ressourcenorientierte Systeme im ländlichen Raum eine Alternative darstellen. Zur Begleitung von Transformationsprozessen ist die Verwendung einer adäquaten Methodik zum Aufzeigen von verschiedenen Systemalternativen (z.B. mathematische Optimierung) zielführend.
Die vorliegende Forschung fokussiert den Fachkräfteerhalt im Gesundheitswesen aus erziehungs- und sozialwissenschaftlicher Perspektive. Dabei geht die Untersuchung den Fragen nach, welche Faktoren den Verbleib im Pflegeberuf beeinflussen, inwieweit die Implementierung gesundheitsfördernder Maßnahmen (BGF) innerhalb des Betrieblichen Gesundheitsmanagements (BGM) zum Erhalt im Pflegeberuf beiträgt und welche gesundheitsfördernden Maßnahmen Pflegefachkräfte benötigen, um (weiterhin) im Beruf arbeiten zu können. Erziehungs- und sozialwissenschafliches Erkenntnisinteresse liegt darin, was zur Vermittlung gesundheitsrelevanter Informationen in der Kindheit beigetragen hat und wie diese Aneignungsprozesse den Begriff der individuellen Gesundheit geprägt haben. Die sozialwissenschaftliche Theoriebasis bildet zum einen das Segment des kulturellen Kapitals der „Habitus/Feld-Theorie“ Bourdieus, der als Aneignung von Kulturkapital die Vermittlung vorschulischer Bildung kennzeichnet, die untrennbar mit dem Individuum verbunden ist. Ein weiteres Teilelement der theoretischen Ausgangsbasis fußt auf autopoietischen Aspekten der „System/Umwelt-Theorie“ Luhmanns, der individuelle Selbststeuerungsprozesse für die Aufnahme und Verarbeitung (gesundheitsrelevanter) Informationen verantwortlich macht. Organisationspädagogische Komponenten bilden den Rahmen des theoretischen Modells, die als Verbindung zwischen Individuum und Organisation fungieren und ädaquate Angebots-strukturen zur Vermittlung einer adressatengerechten Gesundheitsförderung anbieten. Über-einstimmend in allen drei Theorieelementen wird die individuelle Systemgeschichte (Biografie) als relevanter Kernaspekt identifiziert, die sich in der Empirie widerspiegelt.
Zur Beantwortung der Forschungsfragen werden sowohl quantitative als auch qualitative Methoden der empirsichen Sozialforschung gewählt; mit einer Reichweite der Analyse von Dokumenten über qualitative Interviews bis hin zur Entwicklung von Typen.
Als bedeutsame empirische Kernkategorie kristallisiert sich die Zuschreibung „Wertschät-zung/Anerkennung“ heraus, die sich bereits im Theorieteil wiederfindet.
Da die Studie „PflegeWert“ (2011) in der Altenpflege durchgeführt wurde, nimmt die vorliegende Forschung ausschließlich klinisch tätige Pflegefachkräfte in den Blick.
Schlüsselbegriffe: Kulturelles Kapital; Autopoiesis; Organisationspädagogik; System-geschichte; Typologie; Wertschätzung
Computational problems that involve dynamic data, such as physics simulations and program development environments, have been an important
subject of study in programming languages. Recent advances in self-adjusting
computation made progress towards achieving efficient incremental computation by providing algorithmic language abstractions to express computations that respond automatically to dynamic changes in their inputs. Selfadjusting programs have been shown to be efficient for a broad range of problems via an explicit programming style, where the programmer uses specific
primitives to identify, create and operate on data that can change over time.
This dissertation presents implicit self-adjusting computation, a type directed technique for translating purely functional programs into self-adjusting
programs. In this implicit approach, the programmer annotates the (toplevel) input types of the programs to be translated. Type inference finds
all other types, and a type-directed translation rewrites the source program
into an explicitly self-adjusting target program. The type system is related to
information-flow type systems and enjoys decidable type inference via constraint solving. We prove that the translation outputs well-typed self-adjusting
programs and preserves the source program’s input-output behavior, guaranteeing that translated programs respond correctly to all changes to their
data. Using a cost semantics, we also prove that the translation preserves the
asymptotic complexity of the source program.
As a second contribution, we present two techniques to facilitate the processing of large and dynamic data in self-adjusting computation. First, we
present a type system for precise dependency tracking that minimizes the
time and space for storing dependency metadata. The type system improves
the scalability of self-adjusting computation by eliminating an important assumption of prior work that can lead to recording spurious dependencies.
We present a type-directed translation algorithm that generates correct selfadjusting programs without relying on this assumption. Second, we show a
probabilistic-chunking technique to further decrease space usage by controlling the fundamental space-time tradeoff in self-adjusting computation.
We implement implicit self-adjusting computation as an extension to Standard ML with compiler and runtime support. Using the compiler, we are able
to incrementalize an interesting set of applications, including standard list
and matrix benchmarks, ray tracer, PageRank, sparse graph connectivity, and
social circle counts. Our experiments show that our compiler incrementalizes existing code with only trivial amounts of annotation, and the resulting
programs bring asymptotic improvements to large datasets from real-world
applications, leading to orders of magnitude speedups in practice.
Tables or ranked lists summarize facts about a group of entities in a concise and structured fashion. They are found in all kind of domains and easily comprehensible by humans. Some globally prominent examples of such rankings are the tallest buildings in the World, the richest people in Germany, or most powerful cars. The availability of vast amounts of tables or rankings from open domain allows different ways to explore data. Computing similarity between ranked lists, in order to find those lists where entities are presented in a similar order, carries important analytical insights. This thesis presents a novel query-driven Locality Sensitive Hashing (LSH) method, in order to efficiently find similar top-k rankings for a given input ranking. Experiments show that the proposed method provides a far better performance than inverted-index--based approaches, in particular, it is able to outperform the popular prefix-filtering method. Additionally, an LSH-based probabilistic pruning approach is proposed that optimizes the space utilization of inverted indices, while still maintaining a user-provided recall requirement for the results of the similarity search. Further, this thesis addresses the problem of automatically identifying interesting categorical attributes, in order to explore the entity-centric data by organizing them into meaningful categories. Our approach proposes novel statistical measures, beyond known concepts, like information entropy, in order to capture the distribution of data to train a classifier that can predict which categorical attribute will be perceived suitable by humans for data categorization. We further discuss how the information of useful categories can be applied in PANTHEON and PALEO, two data exploration frameworks developed in our group.
Trotz der - theoretisch über die konstruktivistische Systemtheorie begründeten und durch die Organisationsforschung empirisch belegten - zentralen Rolle der Prozesse in der Einzelschule für die Gestaltung von Schulentwicklung, werden durch die Bildungspolitik über die Gestaltung der Systemumwelt wesentliche Impulse für diese Entwicklungsprozesse gesetzt, diese rechtlich und im Bereich der Ressourcen ermöglicht oder eben auch auf diesem Wege blockiert.
In der Arbeit wird ein Modell zur Bestimmung wesentlicher Einflussfaktoren auf bildungspolitische Schulreformen im Bereich institutioneller und parteipolitischer Vetospieler, Interessengruppen der Stakeholder, Medien sowie wissenschaftlicher Akteure entwickelt, über das deren Rationalisierungspotential im Sinne einer stärkeren Evidenzbasierung bildungspolitischer Entscheidungen, ihre Einflussstärke und Implementationsstärke bestimmbar werden. Exemplarisch wird dieses Modell im Anschluss auf die institutionelle Neubestimmung der Evidenzbasierung in Baden-Württemberg angewandt.
Though environmental inequality research has gained extensive interest in the United States, it has received far less attention in Europe and Germany. The main objective of this book is to extend the research on environmental inequality in Germany. This book aims to shed more light on the question of whether minorities in Germany are affected by a disproportionately high burden of environmental pollution, and to increase the general knowledge about the causal mechanisms, which contribute to the unequal distribution of environmental hazards across the population.
To improve our knowledge about environmental inequality in Germany, this book extends previous research in several ways. First, to evaluate the extent of environmental inequality, this book relies on two different data sources. On the on hand, it uses household-level survey data and self-reports about the impairment through air pollution. On the other hand, it combines aggregated census data and objective register-based measures of industrial air pollution by using geographic information systems (GIS). Consequently, this book offers the first analysis of environmental inequality on the national level that uses objective measures of air pollution in Germany. Second, to evaluate the causes of environmental inequality, this book applies a panel data analysis on the household level, thereby offering the first longitudinal analysis of selective migration processes outside the United States. Third, it compares the level of environmental inequality between German metropolitan areas and evaluates to which extent the theoretical arguments of environmental inequality can explain differing levels of environmental inequality across the country. By doing so, this book not only investigates the impact of indicators derived by the standard strand of theoretical reasoning but also includes structural characteristics of the urban space.
All studies presented in this book confirm the disproportionate exposure of minorities to environmental pollution. Minorities live in more polluted areas in Germany but also in more polluted parts of the communities, and this disadvantage is most severe in metropolitan regions. Though this book finds evidence for selective migration processes contributing to the disproportionate exposure of minorities to environmental pollution, it also stresses the importance of urban conditions. Especially cities with centrally located industrial facilities yield a high level of environmental inequality. This poses the question of whether environmental inequality might be the result of two independent processes: 1) urban infrastructure confines residential choices of minorities to the urban core, and 2) urban infrastructure facilitates centrally located industries. In combination, both processes lead to a disproportionate burden of minority households.