## Fachbereich Informatik

### Refine

#### Year of publication

#### Document Type

- Report (139) (remove)

#### Keywords

- Dienstgüte (3)
- Formalisierung (3)
- AG-RESY (1)
- AKLEON (1)
- Ad-hoc-Netz (1)
- Compiler (1)
- Coq (1)
- Extraction (1)
- Formal Semantics (1)
- Fräsen (1)
- Funknetz (1)
- Hals-Nasen-Ohren-Chirurgie (1)
- Hals-Nasen-Ohren-Heilkunde (1)
- Hub-and-Spoke-System (1)
- Hörgerät (1)
- Implantation (1)
- Isabelle/HOL (1)
- Kommunikationsprotokoll (1)
- Komplexitätsklasse NP (1)
- META-AKAD (1)
- Mapping (1)
- Mastoid (1)
- Mastoidektomie (1)
- Model Checking (1)
- NP-hard (1)
- OCL 2.0 (1)
- Ohrenchirurgie (1)
- Peer-to-Peer-Netz (1)
- Profiles (1)
- RONAF (1)
- Regelung (1)
- Reservierungsprotokoll (1)
- Roboter (1)
- Routing (1)
- SDL (1)
- SDL-2000 (1)
- Schädelchirurgie (1)
- Spezifikation (1)
- Sprachprofile (1)
- System Abstractions (1)
- Translation Validation (1)
- UML 2 (1)
- UML Profile (1)
- aliasing (1)
- bedingte Aktionen (1)
- compiler (1)
- domains (1)
- encapsulation (1)
- guarded actions (1)
- hub location (1)
- mastoid (1)
- mastoidectomy (1)
- object-orientation (1)
- otorhinolaryngological surgery (1)
- ownership (1)
- synchrone Sprachen (1)
- synchronous languages (1)
- theorem prover (1)
- translation validation (1)
- types (1)

Monte Carlo & Beyond
(2002)

Many rendering problems can only be solved using Monte Carlo integration. The noise and variance inherent with the statistical method efficiently can be reduced by stratification. So far only uncorrelated stratification methods were used that in addition depend on the dimension of the integration domain. Based on rank-1-lattices we present a new stratification technique that removes this dependency on dimension, is much more efficient by correlation, is trivial to implement, and robust to use. The superiority of the new scheme is demonstrated for standard rendering algorithms.

We present an algorithm for determining quadrature rules for computing the direct illumination of predominantly diffuse objects by high dynamic range images. The new method precisely reproduces fine shadow detail, is much more efficient as compared to Monte Carlo integration, and does not require any manual intervention.

Objective: In some surgical specialties, e.g. orthopedics, robots are already used in the operating room for bony milling work. Oto- and otoneurosurgery may also greatly benefit by robotic enhanced precision. Study Design: Experimental study on robotic milling on oak wood and human temporal bone specimen. Methods: A standard industrial robot with a 6 degrees-of-freedom serial kinematics was used with force feedback to proportionally control the robot speed. Different milling modes and characteristic path parameters were evaluated to generate milling paths based on CAD geometry data of a cochlear implant and an implantable hearing system. Results: The best suited strategy proofed to be the spiral horizontal milling mode with the burr held perpendicularly to the temporal bone surface. In order to avoid high grooves, the distance in between paths should equal half the radius of the cutting burr head. Due to the vibration of the robot’s own motors, a rather high oscillation of the standard deviation of forces was encountered. This oscillation dropped drastically to nearly 0 N, when the burr head reached contact with the dura mater due to its damping characteristics. The cutting burr could be moved a long time on the dura without damaging it, because of its rather blunt head. The robot moved the burr very smoothly according to the encountered resistances. Conclusion: This is the first development of an functioning robotic milling procedure for otoneurosurgery with force-based speed control. It is planned to implement ultrasound-based local navigation and to perform robotic mastoidectomy.

UML and SDL are languages for the development of software systems that have different origins, and have evolved separately for many years. Recently, it can be observed that OMG and ITU, the standardisation bodies responsible for UML and SDL, respectively, are making efforts to harmonise these languages. So far, harmonisation takes place mainly on a conceptual level, by extending and aligning the set of language concepts. In this paper, we argue that harmonisation of languages can be approached both from a syntactic and semantic perspective. We show how a common syntactical basis can be derived from the analysis of the UML meta-model
and the SDL abstract grammar. For this purpose, conceptually sound and well-founded mappings from meta-models to abstract grammars and vice versa are defined and applied. On the semantic level, a comparison between corresponding language constructs is performed.

This report explains basic notions and concepts of Abstract State Machines (ASM) as well as notation for defining ASM models. The objective here is to provide an intuitive understanding of the formalism; for a rigorous definition of the mathematical foundations of ASM, the reader is referred to [2] and [3]. Further references on ASM-related material can be found on the ASM Web Pages [1].

We propose several algorithms for efficient Testing of logical Implication in the case of ground objects. Because the problem of Testing a set of propositional formulas for (un)satisfiability is \(NP\)-complete there's strong evidence that there exist examples for which every algorithm which solves the problem of testing for (un)satisfiability has a runtime that is exponential in the length of the input. So will have our algorithms. We will therefore point out classes of logic programs for which our algorithms have a lower runtime. At the end of this paper we will give an outline of an algorithm for theory refinement which is based on the algorithms described above.

The Chained Lin-Kernighan algorithm (CLK) is one of the best heuristics to solve Traveling Salesman Problems (TSP). In this paper a distributed algorithm is proposed, were nodes in a network locally optimize TSP instances by using the CLK algorithm. Within an Evolutionary Algorithm (EA) network-based framework the resulting tours are modified and exchanged with neighboring nodes. We show that the distributed variant finds better tours compared to the original CLK given the same amount of computation time. For instance fl3795, the original CLK got stuck in local optima in each of 10 runs, whereas the distributed algorithm found optimal tours in each run requiring less than 10 CPU minutes per node on average in an 8 node setup. For instance sw24978, the distributed algorithm had an average solution quality of 0.050% above the optimum, compared to CLK's average solution of 0.119% above the optimum given the same total CPU time (104 seconds). Considering the best tours of both variants for this instance, the distributed algorithm is 0.033% above the optimum and the CLK algorithm 0.099%.

Today, test methods for communication protocols assume, among other things, that the protocol design is specified as a single, monolithic finite state machine (FSM). From this specification, test suites that are capable of detecting output and/or transfer faults in the protocol implementation are derived. Limited applicability ofthese methods is mainly because oftheir specific assumptions, and due to the size of the derived test suite and the resulting test effort for realistic protocols. In this work, the compositional test method (C-method), which exploits the available structure of a communication protocol, is proposed. The C-method first tests each protocol component separately for output and/or transfer faults, using one of the traditional test methods, then checks for composability, and finally tests the composite system for composition faults. To check for composability and to derive the test suite for the detection of composition faults, it is not required to construct the global state machine. Instead, all information is derived from the component state machines, which avoids a potential state explosion and lengthy test cases. Furthermore, the test suite checks for composition faults only. This substantially reduces the size of the test suite and thus the overall test effort.