基于击键动力学和口令的双因素用户验证

提出基于击键动力学和口令的一种新的身份验证方法，该方法监视用户在输入口令时的用户击键特征的有关数据，通过采用监视键盘输入时一种新的三键持续时间的击键特征表示，用一种表示用户节奏的相对击键速度的距离衡量方式，在正常样本上建立用户模式，然后用新样本与用户模式的距离匹配情况来验证用户身份的合法性。实验表明该方法简单实用，识别效率高。     

地震勘探测量数据处理的全面解决方案

本文针对近年来地震勘探技术的发展对测量工作提出的新要求，分析了SSOffiee软件解决问题的方案和技术特色，最后提出了SSOffice软件的发展方向。     

A tree partitioning dynamic policy for OVSF codes assignment in wideband CDMA

This paper proposes some novel techniques to accommodate users with different rate requirements in a wideband code-division multiple-access system employing orthogonal variable spreading factor codes. Two simple static code assignment strategies are first considered, and an improvement based on multicode assignment. Then the new idea of tree partitioning is introduced and used to devise a dynamic code reassignment algorithm. The behavior of these different techniques is experimentally investigated, in terms of call blocking probability and number of required reassignments. The tree partitioning method exhibits very good performances.     

Citation patterns in the Kuwaiti journal Medical Principles and Practice: The first 12 years, 1989-2000

This study investigates the citation patterns in the journal, Medical Principles and Practice from its inception in 1989 through 2000 (volumes 1-9). The data set includes 4740 references appended to the 221 original research articles. All of the citations were entered into a ProCite database for analysis. Specifically, this study addresses: (1) bibliometric patterns of cited works in terms of publication format, subject scatter, authorship characteristics, age of citations, geographic distribution, and language distribution; (2) productivity of journal titles; (3) the role of self-citation; and (4) how selected bibliometric indicators apply. Some of the findings include: journal articles are most frequently cited; English language publications dominate the literature; there is a trend of multiple authorship; and the pattern of aging is below the norm for medical literature. The results of the study can provide a benchmark to measure the user behavior of a particular group of researchers as well as for the provision of collection development and management decisions. This revised version was published online in August 2006 with corrections to the Cover Date.     

Control system design on a power-split CVT for high-power agricultural tractors

The problem considered in this paper is the design and tuning of the control system of a power-split continuously variable transmission (CVT) used in high-power tractors. Power-split CVTs are characterized by the combination of a traditional mechanical transmission and by a continuously-variable transmission. This guarantees, at the same time, smooth variations of the transmission-ratio and high efficiency of the overall transmission system. The control architecture of an hydrostatic power-split CVT is constituted by three main parts: 1) servo-controller on the current of the valve which drives the hydraulic transmission; 2) a servo-controller on the hydraulic transmission-ratio; and 3) a synchronizer which coordinates the hydraulic and the mechanical parts of the CVT. In this work, these three controllers are fully developed, including: design, implementation, and evaluation on an experimental system.     

Impact of Reaction Conditions on MnO2 Genesis during Permanganate Oxidation

To enhance the understanding of the behavior and effects of the precipitation of MnO2 particles in the subsurface generated during in situ chemical oxidation (ISCO) using permanganate, laboratory batch experiments were completed to examine the influence that varied reaction matrix conditions have on the generation and properties of manganese oxides. The conditions examined include organic material type and concentration, permanganate concentration, pH, and the presence of calcium (as a representative divalent cation) in solution. Experimental studies included: (1) spectrophotometric examination of permanganate depletion and manganese oxides generation over time during reactions with trichloroethene; (2) scanning electron microscopy analyses of manganese particle morphology; (3) particle size distribution (filtration) characterization studies; and (4) optical particle sizing and numeration studies. Bench-scale, batch experiments were conducted to focus on fundamental chemical properties affecting particle development under varied potential environmental conditions. The amount of manganese oxides particles that develop, grow, and potentially settle as a result of permanganate ISCO of organic contaminants is a function of the particle size and concentration, the time allowed for particle development, and the impact of matrix conditions on the ability of particles to agglomerate.     

Radiometric sensor for temperature control of food processing

This paper describes a novel planar antenna sensor created for the purpose of noninvasive temperature measurements using microwave radiometry. In order to improve radiometric measurements in industrial applications, a new generation of sensors is introduced, composed of a metallic sheet. Simulations based upon the method of moments is used both to design and to determine their electromagnetic performances. This paper also describes a radiometric device using these sensors to measure and control the temperature of food products during deep freezing processes. The results and discussions are presented.     

Finite element analysis of advanced multilayer capacitors

We establish a systematic methodology to design and analyse electromagnetic components such as advanced multilayer ceramic capacitors (MLCCs) using the finite element (FE) method. We employ a coupled formulation to compute the interaction between the electric and magnetic fields. Unlike a linear distribution of current assumed in the circuit model, an accurate electrostatic solution to model the entire advanced MLCCs (4 × 4 × 27 = 432 cells) is presented. The FE solution is used to compute the lumped parameters for a range of frequencies. These lumped parameters are then used to compute the parasitic elements of the MLCCs. We introduce two algorithms to efficiently analyse the behaviour of a capacitor with changing frequency. The lower frequency (much below the self‐resonant frequency of the capacitor) algorithm separates the effect of the electric and magnetic fields and reduces the computational effort required to solve the FE problem, whereas, the high‐frequency algorithm couples the effect between the electric and the magnetic fields. We use these algorithms in conjunction with a new multiple scale technique to effectively determine the small values of R, L and C in MLCCs. The formulation, the implementation, and the numerical results demonstrate the efficacy of the present FE formulation and establish a systematic methodology to design and analyse advanced electromagnetic components. Copyright © 2003 John Wiley & Sons, Ltd.     

基于USB总线的虚拟频谱分析仪设计

文章详细介绍了基于USB总线的虚拟频谱分析仪的设计过程。该仪器使用嵌入式混合处理器MC56F8323来实现动态信号的实时采集、频谱分析和数字滤波等功能。处理结果由USB2．0接口芯片CY7C68013上传至PC机．以完成数据显示、存储、绘制图形等功能。其中，CY7C68013工作于Slave FIFO模式，以实现与MC56F8323间的数据传输。该系统可同时对两路动态信号进行实时谱分析，每路采样频率高选500kHz。     

可拆装高架火炬的应用

结合工程实例,介绍了我国第一座可拆装高架火炬的基本原理及组成,并对可拆装高架火炬与普通高架火炬在安全、技术、安装、维修、占地面积、投资等方面进行了比较,还分析了高架火炬未来的发展趋势.