基于最大空闲矩形的可重构资源管理方法

可重构硬件如FPGA的规模和集成度的提高使其承载的硬件任务越来越多,FPGA的动态部分重构能力使任务可在系统运行过程中动态地添加或者删除而不影响其他任务的运行,对可重构硬件的资源管理非常重要。该文提出一种基于任务上边界计算最大空闲矩形的算法,使用这些最大空闲矩形能够有效地管理可重构资源,便于更好地利用具有动态部分重构能力的可重构硬件。     

Wave propagation in the presence of empty cracks in an elastic medium

This paper proposes the use of a traction boundary element method (TBEM) to evaluate 3D wave propagation in unbounded elastic media containing cracks whose geometry does not change along one direction. The proposed formulation is developed in the frequency domain and handles the thin-body difficulty presented by the classical boundary element method (BEM). The empty crack may have any geometry and orientation and may even exhibit null thickness. Implementing this model yields hypersingular integrals, which are evaluated here analytically, thereby surmounting one of the drawbacks of this formulation. The TBEM formulation enables the crack to be modelled as a single line, allowing the computation of displacement jumps in the opposing sides of the crack. Furthermore, if this formulation is combined with the classical BEM formulation the displacements in the opposing sides of the crack can be computed by modelling the crack as a closed empty thin body.     

自动删除任意目录下的空文件

本文讨论了VAX计算机系统中无用文件的类型及清理方法，特别讨论了文件长度为来的空文件的删除方法，并提供一个可删除任意指定目标下全部空文件的DCL，命令过程，可以简化系统管理，方便系统管理员和系统操作员。     

Impact of multiple reflow on intermetallic compound of nickel-doped tin-silver-copper on ENImAg substrate

The growth of intermetallic compounds (IMCs) of the tin-silver-copper-nickel/electroless nickel immersion silver (SACN/ENImAg) at the 230 °C during multiple reflows was investigated. The characterization analysis of the samples was conducted using scanning electron microscopy and assisted by a dispersive x-ray analysis. A layer of continuous (Cu, Ni)₆Sn₅ and discontinuous (Ni, Cu)₃Sn₄ intermetallic were formed at the interface after up to the third reflow, while Ag₃Sn nano-sized was formed on the intermetallic surface. The total thickness of the intermetallic layer increased as the reflow increased. The findings also revealed that the intermetallic thickness became thicker with the mass percentage of nickel increased. Hence, the intermetallic growth was controlled mainly by reflow times and nickel content in solders.     

"无"之精神

通过老子的段话引发出有无之间的辨证关系的探讨和思考,研究了城市空间设计中存在的些问题,并提出作者自己的观点。     

走过柏林

本文通过对柏林城市发展史、城市建设特征、绿化体系，以及柏林统一后重建的描述和分析，梳理出这个充满矛盾的城市的过去和现在，探讨当代建筑文化所面临的困境以及人们为走出困境所做的种种努力。     

百年轮回——评柏林新建小城镇的三种模式

本文分析．评论了德国柏林在二十世纪九十年代建设的三个卫星小城镇规划.通过比较,认识其不同的规划思想和手法并概括为三种不同的模式：回归田园、再造小城和现代主义的苏醒。     

上海与柏林--处于永恒变化中的国际城市

本文以两座变化中的大都市——上海和柏林——为例，指出“变化”是这两座城市在发展过程中的相同特点，但是，文章同时突出了“变化”在两座城市中的不同表现。文章对柏林城市历史变迁中的几个节点，例如选侯大街、勃兰登堡门、菩提树下大街，波茨坦广场等予以了更多的笔墨。     

Development of a Ct equation taking into consideration the effect of lot variability on the inactivation of Cryptosporidium parvum oocysts with ozone

Cryptosporidium parvum oocysts are prevalent in surface water and ground water under the influence of surface water, and are difficult to inactivate using free chlorine, the most common disinfectant currently used for treating drinking water. In contrast, it has been shown that ozone is a more effective disinfectant than chlorine. US EPA is currently evaluating a treatment rule, which addresses the control of C. parvum oocysts in drinking water. The use of Ct (average disinfectant concentration multiplied by characteristic contact time) values is being considered as one of the options for demonstrating adequate control of this microbial contaminant. The purpose of this study is to incorporate the variability in inactivation kinetics among different lots of oocysts and to develop a statistical model for Ct based on first-order delayed Chick--Watson inactivation kinetics. A Bayesian approach is used to estimate the delayed Chick--Watson kinetic parameters. A log-linear regression analysis is then used to represent the effect of temperature on the resulting kinetic parameters. The overall model developed in this study provides an approach for water utilities and regulatory agencies to decide on the level of safety needed when developing treatment requirements for the inactivation of C. parvum oocysts with ozone as part of broader risk assessment considerations.     

机器视觉空瓶检测案例设计

文章以机器视觉在啤酒空瓶检测系统中的应用为例,介绍了基于PC的机器视觉系统的组成,及各主要组成部分的功能、特性和设计、选型原则。