298 research outputs found

    Tuning and optimization for a variety of many-core architectures without changing a single line of implementation code using the Alpaka library

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    We present an analysis on optimizing performance of a single C++11 source code using the Alpaka hardware abstraction library. For this we use the general matrix multiplication (GEMM) algorithm in order to show that compilers can optimize Alpaka code effectively when tuning key parameters of the algorithm. We do not intend to rival existing, highly optimized DGEMM versions, but merely choose this example to prove that Alpaka allows for platform-specific tuning with a single source code. In addition we analyze the optimization potential available with vendor-specific compilers when confronted with the heavily templated abstractions of Alpaka. We specifically test the code for bleeding edge architectures such as Nvidia's Tesla P100, Intel's Knights Landing (KNL) and Haswell architecture as well as IBM's Power8 system. On some of these we are able to reach almost 50\% of the peak floating point operation performance using the aforementioned means. When adding compiler-specific #pragmas we are able to reach 5 TFLOPS/s on a P100 and over 1 TFLOPS/s on a KNL system.Comment: Accepted paper for the P\^{}3MA workshop at the ISC 2017 in Frankfur

    Using System Dynamics Models to Understand and Improve Application Landscape Design

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    Application landscape design has become a key challenge for enterprises. For further exploration of related enterprise architecture benefits establishing shared mental models among all application landscape designers is required, i.e. architectural thinking. Thus, to complement existing approaches by modeling human behavior and decision effects which form implicit application landscape evolution principles, we propose the use of System Dynamics. We derive five guidelines from literature for developing a corresponding method. To exemplify the approach, a concrete causal loop diagram on the topic of technological standardization is presented. A subsequent evaluation based on expert interviews demonstrates the model content validity as well as the modeling method\u27s suitability to foster communication among different communities of practice

    Towards a Process Model for Computer-Supported Collaborative Morphological Analysis

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    Morphological analysis (MA) is a method to analyze and design complex systems. MA fosters generation of a large number of solution/system design alternatives, yet it requires a considerable amount of manual effort. Therefore, a number of software tools have been developed to automate the construction of consistent design alternatives and support the exploration of the derived design space. However, available tools lack support for collaboration. This inhibits extended use of MA software in practice since system analysis and design tasks are typically conducted by teams. The purpose of this paper is to enhance the classical MA process model by collaboration support. We review seminal psychological research to guide our process design. We propose a collaborative process model that seeks to increase creativity and prevent psychological phenomena which might impair group performance. The revised process model serves as a basis for collaborative MA software implementations

    On the Scalability of Data Reduction Techniques in Current and Upcoming HPC Systems from an Application Perspective

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    We implement and benchmark parallel I/O methods for the fully-manycore driven particle-in-cell code PIConGPU. Identifying throughput and overall I/O size as a major challenge for applications on today's and future HPC systems, we present a scaling law characterizing performance bottlenecks in state-of-the-art approaches for data reduction. Consequently, we propose, implement and verify multi-threaded data-transformations for the I/O library ADIOS as a feasible way to trade underutilized host-side compute potential on heterogeneous systems for reduced I/O latency.Comment: 15 pages, 5 figures, accepted for DRBSD-1 in conjunction with ISC'1

    Puppet Regime vs. Lead Nation : Der lange Weg zur Anerkennung der DDR durch die USA

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    Am 4. September 1974 nahmen die Vereinigten Staaten von Amerika als 110. Staat der Welt und letzte der drei westlichen Siegermächte diplomatische Beziehungen zur Deutschen Demokratischen Republik auf. Mit der Unterzeichnung der Anerkennungsprotokolle zwischen der westlichen Leadnation und dem östlichen Gefolgsstaat ging die 25-jährige Ära der internationalen Ablehnung der ostdeutschen Staatlichkeit zu Ende. Bedingt durch die bundesdeutsch-amerikanische Erfolgsgeschichte, ist das Verhältnis zwischen dem „anderen“ Deutschland und den USA generell ein vernachlässigtes Kapitel in den deutsch-amerikanischen Beziehungen der Nachkriegszeit. Die vorliegende Arbeit will im Einzelnen untersuchen, inwiefern Ost-Berlins Initiativen in Richtung Washington, die durch die Détente veränderte Konstellation zwischen den Supermächten und die deutschdeutsche Entspannung Anteil an der diplomatischen Aufwertung der DDR hatten. Die Etablierung diplomatischer Beziehungen 1974 sollte der Höhepunkt des Verhältnisses DDR-USA bleiben. Zu einer grundlegenden Veränderung des politischen Gewichts der DDR in den USA kam es nicht, denn in Washington blieb die DDR stets „im Schatten" der Bundesrepublik

    Course Allocation via Stable Matching

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    The allocation of students to courses is a wide-spread and repeated task in higher education, often accomplished by a simple first-come first-served (FCFS) procedure. FCFS is neither stable nor strategy-proof, however. The Nobel Prize in Economic Sciences was awarded to Al Roth and Lloyd Shapley for theirwork on the theory of stable allocations. This theory was influential in many areas, but found surprisingly little application in course allocation as of yet. In this paper, different approaches for course allocation with a focus on appropriate stablematchingmechanisms are surveyed. Two such mechanisms are discussed in more detail, the Gale- Shapley student optimal stable mechanism (SOSM) and the efficiency adjusted deferred acceptance mechanism (EADAM). EADAM can be seen as a fundamental recent contribution which recovers efficiency losses from SOSM at the expense of strategy-proofness. In addition to these two important mechanisms, a survey of recent extensions with respect to the assignment of schedules of courses rather than individual courses is provided. The survey of the theoretical literature is complemented with results of a field experiment, which help understand the benefits of stable matching mechanisms in course allocation applications

    XTT assay of ex vivo saliva biofilms to test antimicrobial influences

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    Objective: Many dental diseases are attributable to biofilms. The screening of antimicrobial substances, in particular, requires a high sample throughput and a realistic model, the evaluation must be as quick and as simple as possible. For this purpose, a colorimetric assay of the tetrazolium salt XTT (sodium 3'-[1-[(phenylamino)-carbony]-3,4-tetrazolium]-bis(4-methoxy-6-nitro)benzene-sulfonic acid hydrate) converted by saliva biofilms is recommended. Cleavage of XTT by dehydrogenase enzymes of metabolically active cells in biofilms yields a highly colored formazan product which is measured photometrically

    XTT assay of ex vivo saliva biofilms to test antimicrobial influences

    Get PDF
    Objective: Many dental diseases are attributable to biofilms. The screening of antimicrobial substances, in particular, requires a high sample throughput and a realistic model, the evaluation must be as quick and as simple as possible. For this purpose, a colorimetric assay of the tetrazolium salt XTT (sodium 3'-[1-[(phenylamino)-carbony]-3,4-tetrazolium]-bis(4-methoxy-6-nitro)benzene-sulfonic acid hydrate) converted by saliva biofilms is recommended. Cleavage of XTT by dehydrogenase enzymes of metabolically active cells in biofilms yields a highly colored formazan product which is measured photometrically

    Differences and similarities in personality functioning across different types of eating disorders

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    Objective: The classification of anorexia nervosa (AN) into subtypes is relevant due to their different symptomatology. However, subtypes (restricting type: AN-R; purging type: AN-P) differ also in terms of their personality functioning. Knowledge about these differences would allow for better treatment stratification. A pilot study indicated differences in structural abilities that can be assessed by the operationalized psychodynamic diagnosis (OPD) system. The aim of this study was therefore to systematically explore differences in personality functioning and personality between the two AN subtypes and bulimia nervosa (BN) using three personality (functioning) constructs. Methods: A total of N = 110 inpatients with AN-R (n = 28), AN-P (n = 40), or BN (n = 42) were recruited in three clinics for psychosomatic medicine. Assignment to the three groups was performed using a comprehensive questionnaire validated for diagnostic purposes (Munich-ED-Quest). Personality functioning was examined using OPD Structure Questionnaire (OPD-SQ), personality by using the Personality Inventory for DSM-5-Brief Form and Big Five Inventory-10. (M)ANOVAs were used to examine differences across eating disorder groups. In addition, correlation and regression analyses were conducted. Results: We observed differences on several sub- and main scales of the OPD-SQ. Whereas patients with BN showed the lowest levels, AN-R patients displayed the highest levels of personality functioning. On some sub- and main scales, such as "affect tolerance," the subtypes of AN differed from BN, whereas on the scale "affect differentiation," AN-R, differed from the other two groups. The total eating disorder pathology score of the Munich-ED-Quest best predicted overall personality structure [stand. beta = 0.650; t(104) = 6.666; p < 0.001] and self-regulation [stand. beta = 0.449; t(104) = 3.628; p < 0.001]. Discussion: Our findings confirm most of the results of the pilot study. These findings can facilitate the development of stratified treatment approaches for eating disorders
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