动画动态定位在网页上的方法

网页上经常会显示一些动画,如重要信息或广告等。本文用JavaScript实现了使动画固定在网页画面的相对位置上,不会被移出画面。     

A probabilistic integrated object recognition and tracking framework

This paper describes a probabilistic integrated object recognition and tracking framework called PIORT, together with two specific methods derived from it, which are evaluated experimentally in several test video sequences. The first step in the proposed framework is a static recognition module that provides class probabilities for each pixel of the image from a set of local features. These probabilities are updated dynamically and supplied to a tracking decision module capable of handling full and partial occlusions. The two specific methods presented use RGB color features and differ in the classifier implemented: one is a Bayesian method based on maximum likelihood and the other one is based on a neural network. The experimental results obtained have shown that, on one hand, the neural net based approach performs similarly and sometimes better than the Bayesian approach when they are integrated within the tracking framework. And on the other hand, our PIORT methods have achieved better results when compared to other published tracking methods in video sequences taken with a moving camera and including full and partial occlusions of the tracked object.     

The analysis of an adaptive workload balancing strategy in computing system resources management

An adaptive workload balancing scheme is analyzed. This scheme is intended to automatically dissolve the imbalance in resource utilization of computing systems and to bring about the proper balance between throughput and turnaround time. This is done by means of the invisible hand due to the bidding of priorities of resource use, with no contradiction between the flexible bid for each resource and the stable price for the entire service. The result of this analysis shows that this scheme would regulate those imbalances, and that it includes the load balancing policy of IBM OS/VS2-2 as a special case. Some considerations and methods on an actual implementation are also presented.This paper is a revised version of material which appeared as Research Report RC5072 of IBM Thomas J. Watson Research Center, Yorktown Heights, New York.On leave from the University of Electro-Communications, Chofu, Tokyo, Japan.     

永磁同步伺服电动机的动态参数

动态参数是影响伺服电动机动态性能最主要的因素之一.动态参数的高低直接决定伺服电动机动态及稳态性能的好坏.对传统的伺服电动机而言,几个主要的动态参数都有较清晰的定义和概念,长期以来在工程实践中广泛使用.但对正弦波驱动的永磁伺服电动机来说,电机的力矩常数Kt、反电势常数Ke、电气时间常数τe、机械时间常数τm和阻尼因数D等都有了新的变化,实践中常引起误解和混淆.文中主要分析永磁同步伺服电动机几个动态参数的含义以及和传统参数之间的差异,并从控制系统的要求出发,对几个最基本的动态参数和参数之间的相互关系进行分析,得出了一些实用的结论.     

新型特洛伊木马技术的研究

本文对特洛伊木马技术所采用的方法进行了分析,介绍了木马程序在植入、加载、隐藏以及在通信方面所采用的方法。在此基础上,分析如何基于动态链接库(DLL)和端口反弹木马技术实现木马程序。最后,给出了防范木马入侵的一般方法。     

新风动态负荷与空调节能

介绍利用空调软件对整栋大楼进行动态负荷计算分析,并以此选择空调设备,不但节省投资,而且达到节能效果.     

Walking-Induced Floor Vibration Case Studies

Excessive floor vibration due to walking is an important serviceability condition to be considered in building design. This paper presents several case studies of problem floors. The case studies include complaints about office, classroom, and retail spaces where vibration levels were found disturbing. In each of these cases, the cause of the vibration was due to people walking around the space. These case studies are presented to reinforce the existence of this problem, to describe nonstructural factors that affect the behavior of floors, and to provide new data to the design and research communities.     

压力AGC系统与其它厚控系统共用的相关性分析

分析证明了动态设定型厚度控制系统与监控、前馈厚度控制系统是相容的,而且保持各自的独立性,无相互影响。BISRA变刚度厚度控制系统和测厚计型厚控系统与监控、前馈厚度控制系统也是相容的,但它们之间有相互影响。BISRA恒压力厚度控制系统与监控、前馈厚度控制系统是不相容的,而动态设定型的恒压力方案是相容的。     

液态金属离子源发射系统电场的模拟分析

发射系统是液态金属离子源的关键部件之一，它的性能的优劣直接影响到整个离子源的工作稳定性和可靠性。因而对其发射系统进行仿真分析，可以很好地指导液态金属离子源的设计制造。本文采用国际上重视的动态喷流柱模型，利用模拟电荷法对液态金属离子源的发射系统的电场进行了计算分析，画出了发射尖端电场强度随不同参数变化的曲线，得出发射尖端表面场强与球冠半径、发射体突出臂长度密切相关，而与引出电极的结构关系甚小的结论，因此液态金属离子源发射特性（如角电流强度）的改善，必须在发射尖的设计制作上下功夫。从而为液态金属离子源的设计提供了一个有效的辅助工具。     

Strain rate sensitivity of the commercial aluminum alloy AA5182-O

The mechanical behavior of the commercial aluminum alloy AA5182-O is investigated at temperatures ranging from −120 to 150 °C and strain rates from 10⁻⁶ to 10⁻¹ s⁻¹. The strain rate sensitivity parameter is determined as a function of temperature and plastic strain, and the strain rate and temperature range in which dynamic strain aging leads to negative strain rate sensitivity is mapped. The effect of dynamic strain aging on ductility and strain hardening is investigated. The sensitivity of the measured quantities to the experimental method employed and their dependence on grain shape are discussed. The experimental data are compared with the predictions of a model constructed based on a recently proposed mechanism for dynamic strain ageing. The mechanism is based on the effect solute clustering at forest dislocations has on the strength of dislocation junctions. The model is shown to reproduce qualitatively the experimental trends.