05 Fakultät Informatik, Elektrotechnik und Informationstechnik

Permanent URI for this collectionhttps://elib.uni-stuttgart.de/handle/11682/6

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Publication Type: search.filters.UBSTyp.ZeitschriftenartikelStart date: 2016End date: 2016

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Now showing 1 - 4 of 4
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    Low power memory allocation and mapping for area-constrained systems-on-chips
    (2016) Strobel, Manuel; Eggenberger, Marcus; Radetzki, Martin
    Large fractions of today’s embedded systems’ power consumption can be attributed to the memory subsystem. In order to reduce this fraction, we propose a mathematical model to optimize on-chip memory configurations for minimal power. We exploit the power reduction effect of splitting memory into subunits with frequently accessed addresses mapped to small memories. The definition of an integer linear programming model enables us to solve the twofold problem of allocating an optimal set of memory instances with varying size on the one hand and finding an optimal mapping of application segments to allocated memories on the other hand. Experimental results yield power reductions of up to 82 % for instruction memory and 73 % for data memory. Area usage, at the same time, deteriorates by only 2.1 %, respectively, 1.2 % on average and even improves in some cases. Flexibility and performance of our model make it a valuable tool for low power system-on-chip design, either for efficient design space exploration or as part of a HW/SW codesign synthesis flow.
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    Pulsed laser porosification of silicon thin films
    (2016) Sämann, Christian; Köhler, Jürgen R.; Dahlinger, Morris; Schubert, Markus B.; Werner, Jürgen H.
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    How are functionally similar code clones syntactically different? An empirical study and a benchmark
    (2016) Wagner, Stefan; Abdulkhaleq, Asim; Bogicevic, Ivan; Ostberg, Jan-Peter; Ramadani, Jasmin
    Background. Today, redundancy in source code, so-called ‘‘clones’’ caused by copy&paste can be found reliably using clone detection tools. Redundancy can arise also independently, however, not caused by copy&paste. At present, it is not clear how only functionally similar clones (FSC) differ from clones created by copy&paste. Our aim is to understand and categorise the syntactical differences in FSCs that distinguish them from copy&paste clones in a way that helps clone detection research. Methods. We conducted an experiment using known functionally similar programs in Java and C from coding contests. We analysed syntactic similarity with traditional detection tools and explored whether concolic clone detection can go beyond syntax. We ran all tools on 2,800 programs and manually categorised the differences in a random sample of 70 program pairs. Results. We found no FSCs where complete files were syntactically similar. We could detect a syntactic similarity in a part of the files in <16% of the program pairs. Concolic detection found 1 of the FSCs. The differences between program pairs were in the categories algorithm, data structure, OO design, I/O and libraries. We selected 58 pairs for an openly accessible benchmark representing these categories. Discussion. The majority of differences between functionally similar clones are beyond the capabilities of current clone detection approaches. Yet, our benchmark can help to drive further clone detection research.
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    Naming the pain in requirements engineering : contemporary problems, causes, and effects in practice
    (2016) Méndez Fernández, Daniel; Wagner, Stefan; Kalinowski, Marcos; Felderer, Michael; Mafra, Priscilla; Vetrò, Antonio; Conte, Tayana; Christiansson, Marie-Therese; Greer, Desmond; Lassenius, Casper; Männistö, Tomi; Nayabi, Maleknaz; Oivo, Markku; Penzenstadler, Birgit; Pfahl, Dietmar; Prikladnicki, Rafael; Ruhe, Günther; Schekelmann, André; Sen, Sagar; Spinola, Rodrigo; Tuzcu, Ahmet; Vara, Jose Luis de la; Wieringa, Roel
    Requirements Engineering (RE) has received much attention in research and practice due to its importance to software project success. Its interdisciplinary nature, the dependency to the customer, and its inherent uncertainty still render the discipline di cult to investigate. This results in a lack of empirical data. These are necessary, however, to demonstrate which practically relevant RE problems exist and to what extent they matter. Motivated by this situation, we initiated the Naming the Pain in Requirements Engineering (NaPiRE) initiative which constitutes a globally distributed, bi-yearly replicated family of surveys on the status quo and problems in practical RE. In this article, we report on the qualitative analysis of data obtained from 228 companies working in 10 countries in various domains and we reveal which contemporary problems practitioners encounter. To this end, we analyse 21 problems derived from the literature with respect to their relevance and criticality in dependency to their context, and we complement this picture with a cause-effect analysis showing the causes and effects surrounding the most critical problems. Our results give us a better understanding of which problems exist and how they manifest themselves in practical environments. Thus, we provide a first step to ground contributions to RE on empirical observations which, until now, were dominated by conventional wisdom only.