椭圆型偏微分方程的加法Schwarz方法

1.引 言 古典加法Schwarz方法(ASM)对于一般问题收敛很慢,在大多数情况下, ASM只能作为预条件子.另一方面,ASM的并行性能非常好,尤其适合大规模粗粒度并行计算,近年来随着并行机系统及并行计算的兴起,ASM重新受到重视.许多学者研究了怎样提高ASM的收敛速度[1,2,4].他们发现加法Schwarz方法之所以收敛慢是由于在内边界上采用     

Fuzzy Weirstrass theorem and convex fuzzy mappings

The convexity and continuity of fuzzy mappings are defined through a linear ordering and a metric on the set of fuzzy numbers. The local-global minimum property of real-valued convex functions is extended to convex fuzzy mappings. It is proved that a strict local minimizer of a quasiconvex fuzzy mapping is also a strict global minimizer. Characterizations for convex fuzzy mappings and quasiconvex fuzzy mappings are given. In addition, the Weirstrass theorem is extended from real-valued functions to fuzzy mappings.     

Computing distance transformations in convex and non-convex domains

It is shown that the well known two-pass sequential local transformation algorithm for computing a distance transformation in rectangular domains may fail in some convex integer domains, but that a four-pass algorithm is sufficient in all two-dimensional convex domains. For non-convex domains the number of passes necessary is shown to be generally greater. Two propagation algorithms for computing the distance transformation are described and shown theoretically and experimentally to be computationally more efficient than the sequential local transformation algorithm in non-convex domains of complex shape. The relationship of the distance transformation in non-convex domains to some more general transformations is explored.     

CXFTV2: A Fortran subroutine for the discrete least squares convex approximation

A Fortan subroutine calculates the least squares approximation to n data values containing random errors subject to non-negative second divided differences (convexity). The method employs a dual active set quadratic programming technique that allows several concavities of an iterate to be corrected simultaneously, which is a distinctive feature of this calculation. A B-spline representation of the iterates reduces each active set calculation to an unconstrained minimization with fewer variables that requires only O(n) computer operations. Details in these techniques including the data structure that establishes the implementation of the method are specified. Numerical testing on a variety of data sets indicates that the subroutine is particularly efficient, terminating after a small number of active set changes, the subroutine being suitable for large numbers of data. A numerical example and its output is provided to help the use of the software.     

Investigating the Impact of Familiarity and Product Conditions on The Ease of Use of a Product

Ease of use is one of the main criteria that customers consider when making a purchase decision. To provide a pleasant experience to the customers, offering products or services consisting of advanced features and functions is no longer enough, due to the existing competition in the global market. In reality, the ease of use of any product is influenced by the conditions of the product and the familiarity of the user. This study examines the influence of the familiarity and the product conditions on the ease of use of a product. This only explains how the conditions of the product and the fa-miliarity of the user, influence on the ease of use of a product when the usage hours of a product increases. A case study would be conducted to validate the results. The results of this study indicate that in the case where both the product conditions and the familiarity has been varied, the ease of use of the product has been increased from 0.229 to 0.380 gradually within the 10 weeks period. Through these results valuable guidance could be obtained by the manufacturers to identify how the ease of use level of a product deviates from the standard level when the usage hours of the product would increase.     

人工气候老化后状态调节时间对芳纶纤维拉伸测试的影响

依据GJB 8496—2015标准中的拉伸方法,对人工气候老化前及老化后不进行状态调节、状态调节1 h、状态调节24 h、状态调节48 h、状态调节96 h后的芳纶纤维的拉伸强度进行测量、比较,从而得到结论:芳纶纤维在人工气候老化后,样品的性能有一定程度下降。在刚刚结束老化后立即进行测试,性能下降达到峰值,待状态调节24 h以后,其老化后性能逐步达到一个相对稳定的状态。建议在实际测试中,人工气候老化后的样品应该在老化结束后,放入恒温恒湿间调节24 h以后再测试。     

低压铸造三维温度场的冷却边界条件处理

低压铸造模具结构比较复杂，存在多处冷却系统对模具进行强制冷却。对低压铸造的多种类型的界面根据其换热的特点作了大致分类。针对每种情况，考虑了冷却介质和冷却管道的个性参数，建立了相应的计算模型，并编制计算程序对实际铸件进行了模拟计算。     

聚碳酸酯的吹塑成型

简介聚碳酸酯吹塑容器的特性与用途,着重分析其吹塑(包括挤出吹塑、共挤吹塑和注射吹塑)成型的机械(螺杆、机筒、型坯机头与吹塑模具)设计要点及工艺条件。     

Gravity optimised particle filter for hand tracking

This paper presents a gravity optimised particle filter (GOPF) where the magnitude of the gravitational force for every particle is proportional to its weight. GOPF attracts nearby particles and replicates new particles as if moving the particles towards the peak of the likelihood distribution, improving the sampling efficiency. GOPF is incorporated into a technique for hand features tracking. A fast approach to hand features detection and labelling using convexity defects is also presented. Experimental results show that GOPF outperforms the standard particle filter and its variants, as well as state-of-the-art CamShift guided particle filter using a significantly reduced number of particles.     

基于单片机的同步发电机自动并列装置设计

同步发电机与电网大系统进行并列是一项非常复杂关键的任务,阐述了同步发电机并列的条件及传统手动并列验证装置及方法。为了使同步发电机在实验室条件下,准确、快速地与电网大系统并列,介绍了一种以AT89C51单片机为核心的同步发电机自动并列装置。分析了该系统的硬件组成及软件设计,该并列装置并网时具有快速、准确等优点。