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排序方式: 共有547条查询结果,搜索用时 15 毫秒
41.
B. Heinrich  K. Pietsch 《Computing》2002,68(3):217-238
The paper deals with Nitsche type mortaring as a finite element method (FEM) for treating non-matching meshes of triangles at the interface of some domain decomposition. The approach is applied to the Poisson equation with Dirichlet boundary conditions (as a model problem) under the aspect that the interface passes re-entrant corners of the domain. For such problems and non-matching meshes with and without local refinement near the re-entrant corner, some properties of the finite element scheme and error estimates are proved. They show that appropriate mesh grading yields convergence rates as known for the classical FEM in presence of regular solutions. Finally, a numerical example illustrates the approach and the theoretical results. Received July 5, 2001; revised February 5, 2002 Published online April 25, 2002  相似文献   
42.
A cascadic multigrid (CMG) method for elliptic problems with strong material jumps is proposed and analyzed. Non–matching grids at interfaces between subdomains are allowed and treated by mortar elements. The arising saddle point problems are solved by a subspace confined conjugate gradient method as smoother for the CMG. Details of algorithmic realization including adaptivity are elaborated. Numerical results illustrate the efficiency of the new subspace CMG algorithm. Received December 14, 2001; revised September 2, 2002 Published online: November 18, 2002  相似文献   
43.
Reports an error in "The Memory Functioning Questionnaire for assessment of memory complaints in adulthood and old age" by Michael J. Gilewski, Elizabeth M. Zelinski and K. Warner Schaie (Psychology and Aging, 1990[Dec], Vol 5[4], 482-490). In the aforementioned article, the author note at the beginning of the article should have contained the following statement: "The Memory Functioning Questionnaire (MFQ) items that appear in the appendix at the end of this article were published previously in 'Memory Functioning Questionnaire (MFQ)' by Michael J. Gilewski and Elizabeth M. Zelinski (Psychopharmacology Bulletin, 1988, Vol. 24, No. 4, pp. 665-670). The current article reflects the construction validation, scoring, and interpretation of the MFQ more accurately than does the article that appeared in Psychopharmacology Bulletin." (The following abstract of the original article appeared in record 1991-08788-001.) The results of psychometric analyses of the Metamemory Questionnaire (MQ) of E. M. Zelinski et al (1980), developed to evaluate perception of everyday memory functioning, are presented for a sample of 343 men and 435 women (aged 16-89 yrs). Exploratory factor analysis yielded 4 correlated factors (General Frequency of Forgetting, Retrospective Functioning, and Mnemonics Usage) that accounted for 36.7% of the variance in responses to the MQ. Factor structure was invariant across age groups (16-54 vs 55-89 yrs), 2 independent samples, and over 3 yrs. Because some of the original MQ scales did not load on the factors, only 64 of the original 92 items were retained for inclusion in the Memory Functioning Questionnaire (MFQ). Internal consistency of MFQ scores is high. The MFQ is therefore reliable for evaluating memory self-appraisals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
44.
This study describes a scenario-driven conceptual design information model and its formation from the viewpoint of the designer55jbrv/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0">s cognition, which is a fundamental part of practical design support tools. Four design meetings were observed in a company, at intervals of several weeks, in order to derive the model. The model consists of information elements generated through the cognitive design problem-solving process, which is a basic design process defined in this study. The study describes the relationship among these information elements, which illustrate the design information model and its formation. The model described in this study is based on scenarios, which promote the evolution of product design. Examples of designers55jbrv/xxlarge8217.gif" alt="rsquo" align="BASELINE" BORDER="0"> discourse in the design meetings are presented to validate the model.  相似文献   
45.
Unlike the connected sum in classical topology, its digital version is shown to have some intrinsic feature. In this paper, we study both the digital fundamental group and the Euler characteristic of a connected sum of digital closed ki-surfaces, i∈{0,1}.  相似文献   
46.
55%铝锌钢卷的铝锌合金结构是由55%铝、43.4%锌与1.6%硅在600℃高温下固化而组成。其整体结构由铝、铁、硅、锌形成致密的四元结晶体,此结晶体在钢板上形成一层屏障,因此能有效地防止腐蚀因子穿透。  相似文献   
47.
根据停车场智能化管理的需要提出了系统设计思想。系统硬件设备由入口设备、出口设备和发卡设备组成,论述了它们的硬件电路设计和软件设计,并重点讨论了IC卡读写的硬、软件设计。  相似文献   
48.
邹航  徐进桥  张峰    郭斌  孔君华  崔磊  李利巍 《焊管》2015,38(9):17-21
钩状裂纹缺陷是导致中碳J55钢超声波探伤不合格的主要原因。针对中碳J55钢HFW焊接过程中出现的不同钩状裂纹缺陷进行了分析,并提出了改进措施。研究结果表明,造成中碳J55钢HFW焊接钩状裂纹的主要原因为钢中的大颗粒夹杂物以及板厚1/4位置严重偏析,且现有的夹杂物及带状组织检验标准难以对J55钢的质量进行有效管控。通过减少单中包连浇炉次、增加铸坯头尾切废量以及改用直弧形连铸机等措施,钩状裂纹缺陷率可大幅降低。  相似文献   
49.
近年来,国内激光雕刻切割控制器技术发展迅速,基于PC的传统控制器已相当成熟.为了显著提高工业生产效率,适应工业生产规模扩张的需要以及工业对系统稳定性要求的提高,目前国内几家专业运动控制器厂家已经实现了激光雕刻切割控制器的完全脱机运行.本文针对脱机控制器的需要设计一款人机交互设备,该设备采用AT89C55WD单片机为主控制器,采用标准的MODBUS协议实现HMI与脱机控制器的可靠通讯.  相似文献   
50.
介绍了一种以AT89C55单片机为核心的热洗车锅炉温度、压力实时检测及报警系统的工作原理及实际应用。  相似文献   
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