Diagnostic techniques for the dynamics of a thin liquid film under forced flow and evaporating conditions

Motivated by quantification of micro-hydrodynamics of a thin liquid film which is present in industrial processes, such as spray cooling, heating (e.g., boiling with the macrolayer and the microlayer), coating, cleaning, and lubrication, we use micro-conductive probes and confocal optical sensors to measure the thickness and dynamic characteristics of a liquid film on a silicon wafer surface with or without heating. The simultaneous measurement on the same liquid film shows that the two techniques are in a good agreement with respect to accuracy, but the optical sensors have a much higher acquisition rate up to 30 kHz which is more suitable for rapid process. The optical sensors are therefore used to measure the instantaneous film thickness in an isothermal flow over a silicon wafer, obtaining the film thickness profile and the interfacial wave. The dynamic thickness of an evaporating film on a horizontal silicon wafer surface is also recorded by the optical sensor for the first time. The results indicate that the critical thickness initiating film instability on the silicon wafer is around 84 μm at heat flux of ~56 kW/m². In general, the tests performed show that the confocal optical sensor is capable of measuring liquid film dynamics at various conditions, while the micro-conductive probe can be used to calibrate the optical sensor by simultaneous measurement of a film under quasi-steady state. The micro-experimental methods provide the solid platform for further investigation of the liquid film dynamics affected by physicochemical properties of the liquid and surfaces as well as thermal-hydraulic conditions.     

Difficulties in the transition from OO analysis to design

The transition from object-oriented (OO) analysis to OO design is indeed difficult. Unfortunately, most of the literature on this topic has incorrectly assessed this issue since the notion of OO analysis was introduced about a decade ago     

Task analysis for computer-aided design (CAD) at a keystroke level

The purpose of this research was to develop a new model to describe and predict a computerized task. AutoCAD was utilized as the experimental tool to collect operating procedure and time data at a keystroke level for a computer aided design (CAD) task. Six undergraduate students participated in the experiment. They were required to complete one simple and one complex engineering drawing. A model which characterized the task performance by software commands and predicted task execution time using keystroke-level model operators was proposed and applied to the analysis of the dialogue data. This task parameter model adopted software commands, e.g. LINE, OFFSET in AutoCAD, to describe the function of a task unit and used up to five parameters to indicate the number of keystrokes, chosen function for a command and ways of starting and ending a command. Each task unit in the task parameter model can be replaced by a number of primitive operators as in the keystroke level model to predict the task execution time. The observed task execution times of all task units were found to be highly correlated with the task execution times predicted by the keystroke level model. Therefore, the task parameter model was proved to be a usable analytical tool for evaluating the human-computer interface (HCI).     

剖析Unix(V6)的存储管理

根据Unix(V6)公开的源代码,详细地分析了Unix(V6)的存储管理技术,及其具体实现过程。     

对数据结构空间局部性的存储保真度的研究(Ⅰ)

该文和文（Ⅱ）、文（Ⅲ）用模型化和量化的手段,分析了阵和树两种常用的大型数据结构所固有的空间局部性,并且利用所建模型统一地分析了数据结构空间局部对存储系统效率的影响,优化编译器的设计等一系列的问题。该文抽象地讨论了阵的空间局部性和变换保真度。     

一种智能网络磁盘(IND)存储系统结构

针对当前计算机存储系统结构中存在的若干问题,文中提出了一种新型的智能网络磁盘(Intelligent Network Disk,IND)存储系统结构.分别给出了IND内部数据的读/写控制、容错处理、负载平衡等智能控制算法,已经构建了一个IND结构的模拟原型IND存储系统.IND存储系统中各个IND都是直接与网络连接,若干个IND组成一个集群存储系统,给用户提供了一个虚拟化的海量存储系统.另外,由于各IND都具有一定的智能度,所以它是一种灵活可变的智能型网络存储器系统.     

The comparative molecular surface analysis (COMSA): a novel tool for molecular design

A new method allowing for 3-D QSAR analysis and the prediction of biological activity is presented. Unlike comparative molecular field analysis (CoMFA)-like techniques, it is based not on a comparison of the properties characterizing a discrete set of points but on the mean electrostatic potential (MEP) calculated and labeling specific areas defined on the molecular surface. A Kohonen self-organizing neural network and partial least square (PLS) analysis have been used for performing such an operation. The series of steroids complexing the corticosteroid (CBG) and testosterone (TBG) globulins, which forms a benchmark measuring the performance of the methods in molecular design, and a series of benzoic acids described by the Hammett sigma constants is used for testing the method. It is demonstrated that a method can be used efficiently to evaluate the responses determined both by the combination of electrostatic and steric effects or by electrostatic effects alone, therefore, two different schemes were developed. The first one, which involves PLS analysis of the full comparative networks, covers both steric and electrostatic effects. This scheme works well for both the CBG and TBG data. The second scheme takes into account only the properties (MEP) of these regions within molecules that can be superimposed with the template molecule. This scheme provides the best predictive power for the benzoic acids series. Comparison of the results from a CoMFA analysis proves that method is at least as effective for the responses limited by electrostatic effects, although it significantly outperforms CoMFA for CBG affinity which is dominated by steric effects.     

Crashworthiness analysis and multi-objective design optimization of a novel lotus root filled tube (LFT)

Structural and Multidisciplinary Optimization - The purpose of this paper is to propose a novel lotus root filled tube (LFT) for improving the energy absorption capability of crash box under axial...     

存储区域网络技术在数据处理中心的应用

随着高性能计算技术的发展,实现对大规模数据的高效存取已成为行业中提高系统整体性能的关键。传统的NFS存储架构,由于其I/O存取带宽低,容易造成TCP/IP局域网络的瓶颈,因此制约了系统整体性能的发挥。为了有效地缓解TCP/IP网络瓶颈,提高海量数据的访问效率,实现网络中各服务器节点对地震数据的共享,我中心自2004年起先后两次进行了存储区域网络的构建,并安装了ADIC公司的SNFS存储共享软件。本文重点介绍了存储区域网的构建、整合方法,并对存储共享软件SNFS的安装与配置做了简单介绍,对其它数据处理中心的存储区域网络构建和应用具有一定的借鉴作用。     

基于智能网络磁盘的存储网格研究

存储网格的实现方式一直是人们关心和亟待解决的问题.在对存储网格和智能网络磁盘的概念进行叙述和分析之后,提出了基于智能网络磁盘的存储网格实现方式.通过在高速局域网上的相关实验和理论探讨,给出了存储网格的这种实现方式的优点、缺点和可行性.这种实现方式的特点是:可以用多种存储设备来构成存储网格;用户可以采用不同厂家的产品提供存储网格共享,可以提供不同的服务质量;设备之间完全独立、互不影响;可以根据存储设备提供的存储容量和存储服务质量来进行收费,对计算网格计费问题的解决提供借鉴和参考;采用松散耦合的、可动态扩展的体系结构,统一的存储空间,扩展性几乎不受任何限制.     

On the design of large flexible space structures (LFSS)

For a general finite-element model of an LFSS, a strictly passive compensator results in an exponentially stable feedback system when actuators and sensors are colocated. In the general case (no colocation) we state necessary and sufficient conditions on the parameterQfor stabilizing a certain number of modes. We give conditions for robust stability and show that feedback does not destabilize the unmodeled modes under certain conditions.     

多媒体电子文件海量数据的分级存储

多媒体电子文件属于海量数据.为了保证对多媒体电子文件的有效存储及降低存储成本,一般需进行分级存储.本文从海量数据的分级存储,来探讨多媒体电子文件的分级存储方式.     

The filter design from data (FD2) problem: Nonlinear Set Membership approach

In the paper, we consider the problem of designing a filter that, operating on noisy measurements of input u and output y of a dynamical system, gives estimates (possibly optimal in some sense) of some other variable of interest z. A large body of literature exists, which investigates this problem assuming that the system equations relating u, y and z are known. However, in most practical situations, the system equations are not (completely) known, but a data set composed of noisy measurements of u, y and z is available. In such situations, a two-step procedure is typically adopted: a model is identified from the set of measured data, and the filter is designed on the basis of the identified model. In this paper, we propose an alternative solution, which uses the available data set of measured u, y and z not for the identification of system dynamics, but for the direct design of the filter. Such a direct design is investigated within the Nonlinear Set Membership framework. In the case of full observability, an almost optimal filter is derived, where optimality refers to minimizing a worst-case estimation error. In the case of partial observability, conditions are given for which the direct design is guaranteed to give bounded estimation error. Three examples are presented, related to the Lorenz chaotic system the first two, and to an automotive application the third one.     

生产实时监测（SIS）系统的设计应用

电厂的厂级实时监控信息系统（简称SIS系统-Supervisory Information System in Plant Level）属于厂级生产过程自动化范畴,实现电厂管理信息系统与各种分散控制系统之间数据交换的桥梁.