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31.
Caches impose a major problem for predicting execution times of real-time systems since the cache behavior depends on the history of previous memory references. Too pessimistic assumptions on cache hits can obtain worst-case execution time estimates that are prohibitive for real-time systems. This paper presents a novel approach for deriving a highly accurate analytical cache hit function for C-programs at compile-time based on the assumption that no external cache interference (e.g. process dispatching or DMA activity) occurs. First, a symbolic tracefile of an instrumented C-program is generated based on symbolic evaluation, which is a static technique to determine the dynamic behavior of programs. All memory references of a program are described by symbolic expressions and recurrences and stored in chronological order in the symbolic tracefile. Second, a cache hit function for several cache architectures is computed based on a cache evaluation technique. Our approach goes beyond previous work by precisely modelling program control flow and program unknowns, modelling large classes of cache architectures, and providing very accurate cache hit predictions. Examples for the SPARC architecture are used to illustrate the accuracy and effectiveness of our symbolic cache prediction. 相似文献
32.
Johann Füller Kurt Matzler Katja Hutter Julia Hautz 《Creativity & Innovation Management》2012,21(3):247-262
Virtual customer integration and open innovation are considered as appropriate means to improve the success of new product development. However, only when consumers are qualified and motivated to contribute promising ideas and relevant know‐how they are able to add value to a producer's innovation process. In this study, we explore the symmetric and asymmetric impact of various creativity components on consumers' idea generation, concept development, or prototype building abilities as well as interest in co‐creation projects. Our results show that creativity components are of different importance. While some characteristics are needed above certain thresholds to successfully accomplish a certain development task, exceeding those does not necessarily lead to better outputs. Other characteristics improve the creative output only if they exceed specific levels. 相似文献
33.
34.
For dynamically measuring position in three degrees of freedom laser tracking systems are well known. Up to now no possibility to measure also orientation using the same laser beam has been known. We present a technique to incorporate orientation measurement into a laser tracking system that requires only minor changes in the existing hardware. The method is based on the analysis of an image of the reflected laser beam intensity distribution. In this image the edges of a slightly modified retroreflector represent a function of the orientation of the end-effector holding the retroreflector. It is shown that from this image the orientation can be determined uniquely and in real time.
A laser tracking system including position and orientation measurement constitutes an instrument to accurately determine robot performance as well as to acquire hints on how to improve robot models and control algorithms. 相似文献
35.
Siddhartha Pathak Johann Michler Kilian Wasmer Surya R. Kalidindi 《Journal of Materials Science》2012,47(2):815-823
In this article, we report on the application of our spherical nanoindentation data analysis protocols to study the mechanical
response of grain boundary regions in as-cast and 30% deformed polycrystalline Fe–3%Si steel. In particular, we demonstrate
that it is possible to investigate the role of grain boundaries in the mechanical deformation of polycrystalline samples by
systematically studying the changes in the indentation stress–strain curves as a function of the distance from the grain boundary.
Such datasets, when combined with the local crystal lattice orientation information obtained using orientation imaging microscopy,
open new avenues for characterizing the mechanical behavior of grain boundaries based on their misorientation angle, dislocation
density content near the boundary, and their propensity for dislocation source/sink behavior. 相似文献
36.
Martial Degbia Bruno Schmaltz Johann Bouclé Juozas V Grazulevicius François Tran‐Van 《Polymer International》2014,63(8):1387-1393
The synthesis of new organic hole transporting materials (HTMs) based on 3,6‐disubstituted 9H‐carbazole‐3,6‐diamine,N,N,N′,N′‐tetraphenyl‐9‐(4‐methoxyphenyl) derivatives and their applications in solid state dye sensitizer solar cells (DSSCs) are described. The effect of the methoxy group localized on the para position of the diphenylamine moieties on the thermal, electronic and electrochemical properties and photovoltaic performance is discussed. In solid state DSSCs, utilization of the aforementioned HTMs in combination with the dye D102 (TiO2/D102/HTM/Au) shows a positive influence of the methoxy group on the photovoltaic conversion efficiency compared with unsubstituted diphenylamine grafted groups. A study on the concentration of the HTM is also carried out and shows an optimal concentration around 200 mg mL?1. Without further optimization, the best device gives a power conversion efficiency of 1.75% under AM 1.5 solar irradiation (100 mW cm?2). 相似文献
37.
38.
Johann Füller Katja Hutter Niclas Kröger 《International Journal of Project Management》2021,39(2):183-195
While crowdsourcing may strengthen a company's innovation performance, it is only rarely embedded in organizations as an innovation practice. Our action research shows that organizations often struggle with crowdsourcing projects as they represent a different form of innovation projects and require additional capabilities and skills e.g., to frame a crowd challenge, deal with IP rights, manage the crowd, or integrate the vast input into innovation projects. To overcome these problems, organizations have to invest in project-led learning to establish easy-to-use templates and routines e.g., to handle offered incentives or the applied winner selection processes. They further need to enable business-led learning as the established innovation structures, processes, and management practices do not cope with crowdsourcing projects and present some rigidities causing high coordination efforts. Organizations that are willing to run a number of consecutive crowdsourcing projects may rapidly improve their capabilities and even come up with scalable crowdsourcing services. Our findings further suggest that crowdsourcing, digital platforms, artificial intelligence, and as-a-service approaches may also add to general project capability building. 相似文献
39.
Peter T. Vanberkel Richard J. Boucherie Erwin W. Hans Johann L. Hurink Nelly Litvak 《OR Spectrum》2012,34(2):371-390
Hospitals traditionally segregate resources into centralized functional departments such as diagnostic departments, ambulatory
care centers, and nursing wards. In recent years this organizational model has been challenged by the idea that higher quality
of care and efficiency in service delivery can be achieved when services are organized around patient groups. Examples include
specialized clinics for breast cancer patients and clinical pathways for diabetes patients. Hospitals are struggling with
the question of whether to become more centralized to achieve economies of scale or more decentralized to achieve economies
of focus. In this paper we examine service and patient group characteristics to study the conditions where a centralized model
is more efficient, and conversely, where a decentralized model is more efficient. This relationship is examined analytically
with a queuing model to determine the most influential factors and then with simulation to fine-tune the results. The tradeoffs
between economies of scale and economies of focus measured by these models are used to derive general management guidelines. 相似文献
40.
Ausra Tomkeviciene Gabija Puckyte Juozas Vidas Grazulevicius Martial Degbia Francois Tran-Van Bruno Schmaltz Vygintas Jankauskas Johann Bouclé 《Synthetic Metals》2012
The synthesis and properties of glass-forming diphenylamino-substituted derivatives of 9-phenylcarbazole with methoxy groups in the different position of diphenylamino moieties are reported. A comparative study on their thermal, optical, photoelectrical and electrochemical properties is presented. The synthesized compounds exhibit high thermal stability with 5% weight loss temperatures ranging from 344 to 475 °C. The derivatives absorb electromagnetic irradiation in the range of 225–425 nm with the band gaps of 2.94–3.08 eV. The ionization energies of the synthesized compounds range from 5.04 to 5.56 eV. The lowest ionization energies and band gaps are observed for compounds containing para methoxy-substituted phenyl rings of diphenylamino moieties and for disubstituted carbazole derivatives. Charge-transporting properties of the selected compounds were tested by time-of-flight technique. Hole drift mobilities in the amorphous layers of the materials reach 10−3 cm2/V s at high electric fields. The derivatives were tested as hole transport materials in solid-state dye sensitized solar cells and showed conversion efficiency up to 0.54%. 相似文献