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排序方式: 共有320条查询结果,搜索用时 593 毫秒
1.
Kalinnik Natalia Kiesel Robert Rauber Thomas Richter Marcel Rünger Gudula 《The Journal of supercomputing》2021,77(4):3484-3515
The Journal of Supercomputing - Scientific application codes are often long-running time- and energy-consuming parallel codes, and the tuning of these methods towards the characteristics of a... 相似文献
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This paper studies a new class of single-machine scheduling problems, which are faced by Just-in-Time-suppliers satisfying a given demand. In these models the processing of jobs leads to a release of a predefined number of product units into inventory. Consumption is triggered by predetermined time-varying, and product-specific demand requests. While all demands have to be fulfilled, the objective is to minimize the resulting product inventory. We investigate different subproblems of this general setting with regard to their computational complexity. For more restricted problem versions strongly polynomial time algorithms are presented. In contrast to this, NP-hardness in the strong sense is proven for more general problem versions. Moreover, for the most general version, even finding a feasible solution is shown to be strongly NP-hard. 相似文献
4.
Malte Krack Marc Secanell Pierre Mertiny 《Structural and Multidisciplinary Optimization》2011,44(1):57-73
A procedure to find the optimal design of a flywheel with a split-type hub is presented. Since cost plays a decisive role
in stationary flywheel energy storage applications, a trade-off between energy and cost is required. Applying a scaling technique,
the multi-objective design problem is reduced to the maximization of the energy-per-cost ratio as the single objective. Both
an analytical and a finite element model were studied. The latter was found to be more than three orders of magnitude more
computationally expensive than the analytical model, while the analytical model can only be regarded as a coarse approximation.
Multifidelity approaches were examined to reduce the computational expense while retaining the high accuracy and large modeling
depth of the finite element model. Using a surrogate-based optimization strategy, the computational cost was reduced to only
one third in comparison to using only the finite element model. A nonlinear interior-point method was employed to find the
optimal rim thicknesses and rotational speed. The benefits of the split-type hub architecture were demonstrated. 相似文献
5.
Jens Lincke Malte Appeltauer Bastian Steinert Robert Hirschfeld 《Science of Computer Programming》2011,76(12):1194-1209
Context-oriented programming (COP) provides dedicated support for defining and composing variations to a basic program behavior. A variation, which is defined within a layer, can be de-/activated for the dynamic extent of a code block. While this mechanism allows for control flow-specific scoping, expressing behavior adaptations can demand alternative scopes. For instance, adaptations can depend on dynamic object structure rather than control flow. We present scenarios for behavior adaptation and identify the need for new scoping mechanisms. The increasing number of scoping mechanisms calls for new language abstractions representing them. We suggest to open the implementation of scoping mechanisms so that developers can extend the COP language core according to their specific needs. Our open implementation moves layer composition into objects to be affected and with that closer to the method dispatch to be changed. We discuss the implementation of established COP scoping mechanisms using our approach and present new scoping mechanisms developed for our enhancements to Lively Kernel. 相似文献
6.
Huth J Buchholz M Kraus JM Mølhave K Gradinaru C v Wichert G Gress TM Neumann H Kestler HA 《Computer methods and programs in biomedicine》2011,104(2):227-234
The direct observation of cells over time using time-lapse microscopy can provide deep insights into many important biological processes. Reliable analyses of motility, proliferation, invasive potential or mortality of cells are essential to many studies involving live cell imaging and can aid in biomarker discovery and diagnostic decisions. Given the vast amount of image- and time-series data produced by modern microscopes, automated analysis is a key feature to capitalize the potential of time-lapse imaging devices. To provide fast and reproducible analyses of multiple aspects of cell behaviour, we developed TimeLapseAnalyzer. Apart from general purpose image enhancements and segmentation procedures, this extensible, self-contained, modular cross-platform package provides dedicated modalities for fast and reliable analysis of multi-target cell tracking, scratch wound healing analysis, cell counting and tube formation analysis in high throughput screening of live-cell experiments. TimeLapseAnalyzer is freely available (MATLAB, Open Source) at http://www.informatik.uni-ulm.de/ni/mitarbeiter/HKestler/tla. 相似文献
7.
Malte Diehl 《Datenschutz und Datensicherheit - DuD》2008,32(4):243-247
Zusammenfassung Im Oktober 2007 trat in Gro?britannien ein Gesetz in Kraft, das es den Polizeibeh?rden erlaubt, die Herausgabe kryptographischer
Schlüssel von ihren Nutzern zu verlangen. Dies ist nur eine von zahlreichen Ma?nahmen, die einen globalen Kurswechsel hin
zu verst?rkter überwachung und Regulierung von Verschlüsselungsmechanismen belegen. In diesem Beitrag werden die Entwicklungen
der Kryptographiegesetzgebung der letzten Jahre und ihr heutiger Stand dokumentiert.
Dipl.-Inform. Malte Diehl Doktorand an der Uni Oldenburg, Department für Informatik, Stipendiat der DFG 相似文献
8.
Malte H.G. Wichmann Jan Sumfleth Marino Quaresimin Karl Schulte 《Engineering Fracture Mechanics》2006,73(16):2346-2359
Nanoparticles and especially carbon nanotubes (CNTs) provide a high potential for the modification of polymers. They are very effective fillers regarding mechanical properties, especially toughness. Furthermore, they allow the implication of functional properties, which are connected to their electrical conductivity, into polymeric matrices. In the present paper, different nanoparticles, as fumed silica and carbon black, were used to optimise the epoxy matrix system of a glass-fibre-reinforced composite. Their nanometre-size enables their application as particle-reinforcement in FRPs produced by the resin-transfer-moulding method (RTM), without being filtered by the glass-fibre bundles. Additionally, an electrical field was applied during curing, in order to enhance orientation of the nanofillers in z-direction. The interlaminar shear strengths of the nanoparticle modified composites were significantly improved (+16%) by adding only 0.3 wt.% of CNTs. The interlaminar toughness GIc and GIIc was not affected in a comparable manner. The laminates containing carbon nanotubes exhibited a relatively high electrical conductivity at very low filler contents, which allows the implication of functional properties, such as stress-strain monitoring and damage detection. 相似文献
9.
Multiprobe high pressure measurements require electrical leads in the sample chamber. Compared to conventional wire-based techniques, metallic tracks patterned onto the anvil surface improve reliability and ease of use, and enable novel and more demanding measurements under high pressure. We have developed new anvil designs based on sputter-deposited tracks on alumina and moissanite anvils. These anvils allow convenient and reliable measurements of electrical transport properties or of the magnetic susceptibility under hydrostatic conditions, as demonstrated by test measurements on Pb and Ca(3)Ru(2)O(7). 相似文献
10.
Matthias Schulz Ute Pippardt Lutz Kiesel Katrin Ritter Ralf Kriegel 《American Institute of Chemical Engineers》2012,58(10):3195-3202
Ba0.5Sr0.5Co0.8Fe0.2O3‐δ tubes, capillaries, capillary modules, and asymmetric membranes were prepared and tested for oxygen permeation in a dead‐end vacuum operation mode at temperatures up to 850°C. The capillary module was built up by reactive air brazing using seven capillaries and a supply tube. Two machined discs were used as an end cap and as a connector plate. The oxygen permeation behaves according to Wagner at small driving forces, but significant negative deviations were observed for asymmetric membranes and single capillaries at higher ones. This is caused by pressure drops at the vacuum side for single capillaries. The highest oxygen flux was revealed for the capillary module with 175.5 mL(STP)/min at a low‐vacuum pressure of 0.042 bar at 850°C, but the asymmetric membrane showing a little bit higher flux at moderate vacuum pressures above 0.07 bar. © 2012 American Institute of Chemical Engineers AIChE J, 58: 3195–3202, 2012 相似文献