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71.
An important goal for the design of visual displays is to determine how much realism or scene complexity to include in a computer simulation to reach a given level of performance. This is an important task since the present trend in computer graphics is to include the highest level of realism or scene complexity possible in a simulation. However, it may not be necessary to always include the highest level of realism or complexity to reach an acceptable level of performance. In fact, needless degrees of realism, and thus computational resources, may be wasted in the quest for ‘photographic’ realism. To study the relationship between scene complexity and human performance, three different simulations of scene complexity were modeled for a final approach task. The subject's task were to estimate two aspects of situation awareness, perceived altitude and aimpoint, during a simulated final approach at nine unique distances to threshold. The three levels of scene complexity included a homogeneous Lambertian shaded flat surface, farmlands, and farmlands with hills. The results indicated that increasing the level of scene complexity lead to better performance in judging both altitude and aimpoint during the simulated final approach. The relationship between scene complexity and perceptual performance for computer graphics simulations are discussed.  相似文献   
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73.
In this paper, we are exploring the approach to utilize system-specific static analyses of code with the goal to improve software quality for specific software systems. Specialized analyses, tailored for a particular system, make it possible to take advantage of system/domain knowledge that is not available to more generic analyses. Furthermore, analyses can be selected and/or developed in order to best meet the challenges and specific issues of the system at hand. As a result, such analyses can be used as a complement to more generic code analysis tools because they are likely to have a better impact on (business) concerns such as improving certain software quality attributes and reducing certain classes of failures. We present a case study of a large, industrial embedded system, giving examples of what kinds of analyses could be realized and demonstrate the feasibility of implementing such analyses. We synthesize lessons learned based on our case study and provide recommendations on how to realize system-specific analyses and how to get them adopted by industry.  相似文献   
74.
This paper presents a highly reliable macro to micro domain interconnection technology for microfluidic applications using Polydimethylsiloxane (PDMS) casting techniques. Characteristic to the interconnectors are long flanges fabricated in the PDMS film; therefore the contact area between PDMS and tubes is considerably increased compared to other interconnection technologies. Thus, both glass capillaries and Polytetrafluoroethylene (PTFE) tubes can be held in position very reliably and rigidly. To test the reliability of the interconnectors, PTFE tubes were successfully connected to microfluidic chips without the aid of any liquid adhesives. Both leakage and pull-out tests demonstrated the functionality and reliability of the PDMS interconnectors; no leakage was detected under a working pressure up to 400?kPa. A pull-out test yielded a pull-out force of 22.45?N. Furthermore, once a casting mould is fabricated, it can be re-used as a template repeatedly achieving a low cost technology and making it suitable for batch production.  相似文献   
75.
76.
Ein international erfolgreiches Schema für Cybersicherheits-Zertifizierungen bedarf akzeptierter und implementierter Sicherheitsstandards. Dieser Artikel erörtert kritisch die komplexen Anforderungen hinsichtlich der Vollständigkeit, Dynamik und Durchsetzung aus europäischer Perspektive und zeigt am Beispiel der eIDAS-Verordnung die Herausforderungen bei der Umsetzung auf.  相似文献   
77.
Die im Art. 17 der Datenschutz-Grundverordnung (DSGVO) enthaltene Regelungen für das Löschen, insbesondere die Pflicht, Dritte über die Löschanfragen zu informieren, sind mit einem hohen Aufwand für die Verantwortlichen verbunden, sodaßs sie ohne eine technische Unterstützung in der Praxis nicht umgesetzt werden können. Die zurzeit jedoch fehlenden technischen Lösungen führen zu einer Lücke zwischen den Rechtsvorschriften und den derzeitigen technischen Möglichkeiten, während die DSGVO ab Mai 2018 anzuwenden ist. Um diese Lücke zu schließen, wird im Folgenden zunächst analysiert, welche Möglichkeiten im Allgemeinen bestehen, das Löschen im Internet gemäß Art. 17 technisch umzusetzen. Anschließend wird eine Lösung für die Verteilung der Löschanfragen an die Verantwortlichen vorgestellt, das auf der Kombination der Technik mit dem Gesetz beruht und sowohl den Betroffenen als auch den Verantwortlichen ein Werkzeug zur Unterstützung des Art. 17 zur Verfügung stellt.  相似文献   
78.
    
This paper presents results out of investigations of the DEBRA‐25 wind turbine blades. Almost unique in the history of modern wind energy, these blades were in operation for 18 years next to a weather station and were investigated afterward. Therefore, the loads experienced in the operational life could be post‐processed accurately with the measured data of the weather station and the turbine. The blades are made of materials that are similar with today's wind turbines. Furthermore, intensive laboratory tests and free field tests have been carried out, and all load assumptions and data and results are still available today. The results include experimental investigations on the moisture content of the load‐carrying material, static and fatigue behavior of the material, the relaxation of the coupling joints, the natural frequencies of the blade and a full scale static blade test. It is shown that the structural performance of the DEBRA‐25 service blades is comparable with modern wind turbine blades. Although some damage was found by visual inspection, the service blade of the DEBRA‐25 showed excellent mechanical behavior in the full scale blade test. Only small changes of the edgewise eigenfrequencies were detected. The pre‐tensioning forces of the IKEA bolts, where the two blade parts are connected, were measured and were still adequate. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
79.
    
John Kraft  Mark Rodekohr 《Energy》1980,5(12):1193-1202
This paper uses a random coefficient regression approach to estimate the demand for gasoline by pooling cross-sectional (state level) and time series data. The analysis proceeds by estimating two alternative models, namely a stock adjustment model and a flow adjustment model. The two models are estimated using state level data on gasoline consumption, gasoline price, income and the stock of automobiles. The random coefficient specification of each demand model is estimated assuming heteroskedastic disturbances across states, autocorrelated disturbances over time and variable intercept and slope coefficients across states. The resultant price and income elasticities are compared and inferences concerning the ability of the flow adjustment model to approximate the underlying demand function are made.  相似文献   
80.
人们说,车轮是人类最伟大的发明。当然很难就此争论其是与非。但是处于第二位的是什么呢?可能不起眼的砖块是竞选者之一。它体积之小,可握于手中,但是数块砖叠砌在一起又是如此的巨大,在太空上用肉眼就可以看到用它们所建造的建筑。诚然,虽说中国的万里长城并不是每一部分都由烧制砖块砌成,但是大部分采用了这种材料。尤其是墙的顶部用灰泥嵌缝并结合恰当,这样就不会有植物从中长出来了。  相似文献   
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