Inter-program Optimizations for Disk Energy Reduction

Compiler support for power and energy management has been shown to be effective in reducing overall power dissipation and energy consumption of programs, for instance through compiler-directed resource hibernation and dynamic frequency and voltage scaling. The multi-programming model with virtual memory presents a virtualized view of the machine such that compilers typically take single programs as input, without the knowledge of other programs that may run at the same time on the target machine. This work investigates the benefits of optimizing sets of programs with the goal of reducing overall disk energy. The two key ideas are to synchronize the disk accesses across a group of programs thereby allowing longer disk idle periods, and to utilize execution context knowledge to allocate maximal buffer sizes. The compiler inserts runtime system calls for profiling the application and disk, uses execution context in allocating buffers, and synchronizes disk accesses with an inverse barrier policy. Data prefetching has been added to mitigate the overhead of synchronization. Experimental results are based on three streaming applications and their subsets. The experiments show that inter-program optimizations can have significant disk energy savings over individually optimized programs. Applying the most aggressive inter-program optimizations result in energy savings of up to 49%, and saving 34% on average

Konzeption einer deklarativen Wissensbasis über recyclingrelevante Materialien

Das Recycling von Produkten und Produktionsreststoffen erlangt als Einflußfaktor für wirtschaftliche Entscheidungsprozesse eine immer größere Bedeutung. Die Integration von recyclingrelevanten Daten in betriebliche Informationsstrukturen sollte in Zukunft durch wissensbasierte Methoden unterstützt werden. Wir stellen Ansätze für eine Wissensbasis zur recyclinggerechten Produkt- und Produktionsplanung vor, und gehen dann genauer auf das grundlegende Modul über Materialien ein. Es wird untersucht, welche Evolutionstechniken sich zur Pflege derartiger Wissensbestände eignen, z.B. zur Validierung vorhandener und Exploration neuer Materialien im Hinblick auf ihre Recycelbarkeit

Towards a sharable knowledge base on recyclable plastics

For economic decision processes, recycling of products and production waste is getting more important. In the future the integration of recycling-relevant data into the information structures of companies should be supported by knowledge-based methods. We present the conception of a knowledge base for recycling-oriented product and production planning (RPPP). Then we take a detailed look at the fundamental materials module. We examine which evolution techniques are appropriate for the maintenance of such knowledge bases. In particular, we study the validation of existing materials and the exploration of new ones with regard to their recyclability. An appendix includes a script of a real sample dialogue with our knowledge base on recyclable thermoplastics (RTPLAST)

An Interactive Environment for Data Partitioning and Distribution

An approach to distributed memory parallel programming that has recently become popular is one where the programmer explicitly specifies the data decomposition using language extensions, and a compiler generates all the communication. While this frees the programmer from the tedium of thinking about message-passing, no assistance is provided in determining the data decomposition scheme that gives the best performance on the target machine. In this paper, we propose an interactive software tool that provides assistance for this very task. The proposed tool also computes performance estimates for any chosen data partitioning scheme, allowing the programmer to experiment with several different strategies without ever running the program on the machine

07041 Abstracts Collection -- Power-aware Computing Systems

From January 21, 2007 to January 26, 2007, the Dagstuhl Seminar 07041``Power-aware Computing Systems\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and discussed ongoing work and open problems. This report compiles abstracts of the seminar presentations as well as the seminar results and ideas, providing hyperlinks to full papers wherever possible

05141 Abstracts Collection -- Power-aware Computing Systems

From 03.04.05 to 08.04.05, the Dagstuhl Seminar 05141 ``Power-aware Computing Systems\u27\u27 was held in the International Conference and Research Center (IBFI), Schloss Dagstuhl. During the seminar, several participants presented their current research, and ongoing work and discussed open problems. Abstracts of the presentations given during the seminar as well as abstracts of seminar results and ideas are collected in this paper. The first section describes the seminar topics and goals. Links to extended abstracts or full papers are provided, if available

Comparison of Guidance Modes for the AUV “Slocum Glider ” in Time-Varying Ocean Flows

Abstract — This paper presents possibilities for the reliable guidance of an AUV “Slocum Glider ” in a time-varying oceans flows. The presented guidance modes consider the restricted information during a real mission about the actual position and ocean current conditions as well as the available control modes of a glider. A faster-than-real-time, full software stack simulator for the Slocum glider will be described in order to test the developed guidance modes under real mission conditions. Keywords—component; AUV “Slocum Glider”; Path Planning; Glider Simulator; Time-Varying Ocean Flows; Dead Reckonin