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21.
Filter-driven optimization based on the extended Kalman filter concept is used here for the numerical solution of crack and
flaw identification problems in elastodynamics. The mechanical modeling of the studied two-dimensional problem, which includes
the effect of unilateral contact along the sides of the crack, is done with the help of the boundary element method. The effect
of various dynamical test loads and the applicability of this method for crack and defect identification in disks are investigated.
The work has been supported by the German Research Foundation (DFG). Partial support has been provided by a Greek-German Research
Cooperation Grant (IKYDA2001). This support is greatfully acknowledged. 相似文献
22.
Marek Engelhardt Martin Schanz Georgios E. Stavroulakis Heinz Antes 《Optimization and Engineering》2006,7(1):63-79
An inverse problem in engineering mechanics is considered where the position and the geometry of three-dimensional, ellipsoidal
defects are identified by using measurements of the mechanical response under static loading on the external surface of the
structure. The problem is solved by appropriate combination of genetic optimization (GO) and boundary element method (BEM)
and following previously published two-dimensional problems. The three-dimensional case presents some additional difficulties.
Furthermore, the function of several genetic operators and the effect of the parameters of genetic optimization on the efficiency
of the solution has been numerically examined. 相似文献
23.
Heinz‐Dieter Bürger 《真空研究与实践》2004,16(2):67-70
The use of the high evaporation enthalpy of water is one of the oldest technologies of refrigeration for food preservation used by the mankind. One could nearly celebrate the true 5000th anniversary of this technology. Nowadays we call the refrigeration by evaporation from wet surfaces “adiabatic refrigeration”, it regulates, for instance, our body heat by evaporating sweat. After the introduction of some vacuum pumps into the experimental scientific works, 250 years ago, namely in Great Britan, the modern form of “artificial” refrigeration began its career, the evaporation of liquids under the absence of permanent gasses in vacuum. The vacuum refrigeration has been nearly abruptly stopped by the development of compression refrigeration processes, about 150 years ago. Only after world war 2, a reintroduction of vacuum refrigeration began again. Now, at the beginning of the 3. milennium, there are good chances for recovering terrain. 相似文献
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Georg Sonnek Heinz Reinheckel Karl-Günther Baumgarten 《Advanced Synthesis \u0026amp; Catalysis》1976,318(5):756-760
Aluminium Alkyls with Heteroatoms. II. Preparation of Tris[(3-trimethylsilyl)-propyl]aluminium Tris[(3-trimethylsilyl)-propyl]aluminium is prepared by disproportionation and by an olefine displacement reaction in a circulation process. The reaction way is investigated with the aid of 1H-n.m.r.- and i.r.-spectroscopy. 相似文献
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Weirich Sebastian; Hoffmann Ferdinand; Mei?ner Lucia; Heinz Andreas; Bengner Thomas 《Canadian Metallurgical Quarterly》2011,25(6):806
Objective: It has been suggested that women have a better face recognition memory than men. Here we analyzed whether this advantage depends on a better encoding or consolidation of information and if the advantage is visible during short-term memory (STM), only, or whether it also remains evident in long-term memory (LTM). Method: We tested short- and long-term face recognition memory in 36 nonclinical participants (19 women). We varied the duration of item presentation (1, 5, and 10 s), the time of testing (immediately after the study phase, 1 hr, and 24 hr later), and the possibility to reencode items (none, immediately after the study phase, after 1 hr). Results: Women showed better overall face recognition memory than men (ηp2 = .15, p 相似文献