Present-day software systems have to fulfill an increasing number of requirements rendering them more and more complex. Many systems need to anticipate changing contexts (self-adaptive systems) or need to adapt to changing business rules or requirements (self-optimizing systems). The challenge of 21th century software development will be to cope with these aspects. We believe that the role concept offers a simple way to adapt object-oriented programs to their changing contexts. In a role-based language, an object plays multiple roles during its lifetime. If the contexts are represented as first-class entities, they provide dynamic views to the object-oriented program, and if the context changes, the dynamic views can be switched easily, and the software system adapts automatically. However, the concepts of roles and dynamic contexts have been discussed for a long time in many areas of computer science. So far, their implementation in an existing object-oriented language requires a specific runtime environment. Also, classical object-oriented languages and their runtime systems are not able to cope with essential role-specific features, such as true delegation or dynamic binding of roles. As a solution, this work presents a simple implementation pattern for role-based objects that does not require a specific runtime system, SCROLL (SCala ROles Language). The implementation pattern is demonstrated on the basis of the Scala language. As technical support from Scala, the pattern requires dynamic mixins, compiler-translated function calls, and implicit conversions. The implementation details of the pattern are hidden in a Scala library and therefore transparent to Scala programmers. The SCROLL library supports roles embedded in structured contexts, so-called compartments. We show that they are specific, hierarchic runtime views, which enables hierarchic view-based programming for free in Scala. We also discuss how to apply the implementation pattern of SCROLL for other languages, in particular for behavioral modeling languages in MDSD. This discussion shows that the SCROLL pattern can be embedded into the generated code, so that it still is hidden to the developer, but does not require a specific runtime system. Using the pattern in model-driven code generation enables dynamic views for all kinds of modeling languages. And therefore, this paper shows a way how to realize dynamic views for all modeling languages in MDSD.

Background: Dynamic programming algorithms provide exact solutions to many problems in computational biology, such as sequence alignment, RNA folding, hidden Markov models (HMMs), and scoring of phylogenetic trees. Structurally analogous algorithms compute optimal solutions, evaluate score distributions, and perform stochastic sampling. This is explained in the theory of Algebraic Dynamic Programming (ADP) by a strict separation of state space traversal (usually represented by a context free grammar), scoring (encoded as an algebra), and choice rule. A key ingredient in this theory is the use of yield parsers that operate on the ordered input data structure, usually strings or ordered trees. The computation of ensemble properties, such as a posteriori probabilities of HMMs or partition functions in RNA folding, requires the combination of two distinct, but intimately related algorithms, known as the inside and the outside recursion. Only the inside recursions are covered by the classical ADP theory. Results: The ideas of ADP are generalized to a much wider scope of data structures by relaxing the concept of parsing. This allows us to formalize the conceptual complementarity of inside and outside variables in a natural way. We demonstrate that outside recursions are generically derivable from inside decomposition schemes. In addition to rephrasing the well-known algorithms for HMMs, pairwise sequence alignment, and RNA folding we show how the TSP and the shortest Hamiltonian path problem can be implemented efficiently in the extended ADP framework. As a showcase application we investigate the ancient evolution of HOX gene clusters in terms of shortest Hamiltonian paths. Conclusions: The generalized ADP framework presented here greatly facilitates the development and implementation of dynamic programming algorithms for a wide spectrum of applications.

Inter-Vehicular Communication is an optimistic technology to enhance road safety. The wireless medium often used to exchange vital information. Wi-Fi is also used to share the information, but it required an access point hardware to communicate. Wi-Fi Direct enabled the device exchange information without a hardware access point. Over the last decades, the usage of wireless technology has been increased and transformed the way electronic devices interact and communicate. Wi-Fi Direct technology provides peer-to-peer communication. So, Wi-Fi is highly applicable for car-to-car communication because of its High data rate, range, standard usage. Within the framework of this thesis concept of prototyping car-to-car communication by using Wi-Fi Direct service in smartphones. Focus here to optimize resource utilization and to provide basic functionality within the programming mode.

This report details the design of a garbage collection (GC) module, which introduces modern GC features to the domain of embedded implementations. The described design supports weak references and feeds reference queues. Its architecture allows multiple concurrent application cores operating as mutators on the shared memory managed by the GC module. The garbage collection is exact and fully concurrent so as to enable the uninterrupted computational progress of the mutators. It combines a distributed root marking with a centralized heap scan of the managed memory. It features a novel mark-and-copy GC strategy on a segmented memory, which thereby overcomes both the tremendous space overhead of two-space copying and the compaction race of mark-and-compact approaches. The proposed GC architecture has been practically implemented and proven using the embedded bytecode processor SHAP as a sample testbed. The synthesis results for settings up to three SHAP mutator cores are given and online functional measurements are presented. Basic performance dependencies on the system configuration are evaluated.

This report presents the SHAP platform consisting of its microarchitecture and its implementation of the Java Virtual Machine (JVM). Like quite a few other embedded implementations of the Java platform, the SHAP microarchitecture relies on an instruction set architecture based on Java bytecode. Unlike them, it, however, features a design with well-encapsulated components autonomously managing their duties on rather high abstraction levels. Thus, permanent runtime duties are transferred from the central computing core to concurrently working components so that it can actually spent a larger fraction of time executing application code. The degree of parallelity between the application and the runtime implementation is increased. Currently, the stack and heap management including the automatic garbage collection are implemented this way. After detailing the design of the microarchitecture, the SHAP implementation of the Java Virtual Machine is described. A major focus is laid on the presentation of the layout and the use of the runtime data structures representing the various language abstractions provided by Java. Also, the boot sequence starting the JVM is described.

The goal of the IWST workshop series is to create and foster a forum around advancements of or experience in Smalltalk. The workshop welcomes contributions to all aspects, theoretical as well as practical, of Smalltalk-related topics. / Zweck der IWST-Workshop-Reihe ist die Formung und Pflege eines Forums fŸr die Diskussion von Fortschritten und Arbeitsergebnissen mit der Programmierumgebung Smalltalk. Der Workshop beinhaltet BeitrŠge zu allen Aspekten von auf Smalltalk bezogenen Arbeiten sowohl theoretischer als auch praktischer Natur.

Auf der Grundlage eines mathematischen Modells zur Beschreibung der Druckentwicklung in pneumatischen Verdichtungsanlagen, welche zur Herstellung von Kernen und Formen dienen, wurden Computerprogramme erstellt. Mit deren Hilfe können Parameteridentifikationen zur Ermittlung maschinentechnischer Größen (Durchflusskoeffizienten, Ventilfunktionen) durchgeführt und Druckverläufe berechnet werden. Es erfolgt der Nachweis, dass das mathematische Modell die Prozesse hinreichend genau wiedergibt. Im theoretischen Teil werden Betrachtungen zu Einflussgrößen auf die Druckentwicklung angestellt. Dabei wurde festgestellt, dass das Maschinenbehältervolumen den größten Einfluss ausübt. Weiterhin sind Untersuchungen bzgl. der Druckentwicklungsabhängigkeit von Ventileigenschaften durchgeführt worden. Als Kriterium zur Bewertung von pneumatischen Anlagen wurden die Energiebilanz und der Druckanstieg über dem Formstoff diskutiert.

Die PDAs von Palm Inc. und seinen Lizenznehmern werden gerne zur Adress- und Terminverwaltung eingesetzt. Damit ist ihr Leistungspotential jedoch nicht erschöpft. Wer gerne selbst Applikationen für Palm PDAs entwickeln möchte, ist dabei nicht zwingend auf eine windowsbasierte Entwicklungsumgebung angewiesen. Unter Linux gibt es Compiler, Ressourceeditoren und Emulatoren für PalmOS. Ich werde in meinem Vortrag diese Werkzeuge vorstellen, demonstrieren und ein Beispielprogramm zeigen.

The diploma thesis with the subject ¨Parallel Genetic Algorithms with Applications¨ deals with the parallelization of Genetic Algorithms for the creation of efficient optimization methods especially for simulation based application problems. First, an introduction to Genetic Algorithms and an overview of possible parallelization approaches as well as already published results of research are given. This is followed by a detailed explanation of the conception and realization of own Parallel Genetic Algorithms. The paper is rounded off by an particularized description of the results of extensive test runs on the Chemnitzer Linux-Cluster (CLiC). / Die Diplomarbeit zum Thema ¨Parallele Genetische Algorithmen mit Anwendungen¨ befasst sich mit der Parallelisierung Genetischer Algorithmen zur Erzeugung effizienter Optimierungsverfahren für insbesondere simulationsbasierte Anwendungsprobleme. Zunächst werden eine Einführung in Genetische Algorithmen sowie ein Überblick über mögliche Parallelisierungsansätze und bereits veröffentlichte Forschungsergebnisse gegeben. Dem schließt sich eine detaillierte Erläuterung der Konzeption und Umsetzung eigener Paralleler Genetischer Algorithmen an. Abgerundet wird die Arbeit durch eine ausführliche Darstellung der Ergebnisse umfangreicher Testläufe auf dem Chemnitzer Linux-Cluster (CLiC).

The purpose of this paper is to supply a summary of library subroutines and functions for parallel MIMD computers. The subroutines have been developed and continously extended at the University of Chemnitz since the end of the eighties. In detail, they are concerned with vector operations, inter-processor communication and simple graphic output to workstations. One of the most valuable features is the machine-independence of the communication subroutines proposed in this paper for a hypercube topology of the parallel processors (excepting a kernel of only two primitive system-dependend operations). They were implemented and tested for different hardware and operating systems including PARIX for transputers and PowerPC, nCube, PVM, MPI. The vector subroutines are optimized by the use of C language and unrolled loops (BLAS1-like). Hardware-optimized BLAS1 routines may be integrated. The paper includes hints for programmers how to use the libraries with both Fortran and C programs.