河南电力远程教育网系统安全方案开发应用

河南省电力公司远程教育平台,作为一个省内电力系统职工的再教育、技术培训、技能培训中心,访问量大,安全要求高,我们在软件设计时充分考虑到系统的安全性。     

Nd3+ Doped Silicate Glass Photonic Crystal Fiber with Random Hole Distributions

The fabrication of one kind of large core area Nd3 doped silicate glass photonic crystal fiber, and demonstration of the fiber's waveguidence properties were reported. This fiber owns a random air hole distribution in the cladding. The measured minimum loss of this kind of fiber is 10 dB·m-1 at 660 nm. These fibers can sustain only a single mode at least over wavelength ranging from 660 nm to 980 nm.     

Critical building separation distance in reducing pounding risk under earthquake excitation

A separation distance between adjacent buildings is provided to reduce the risk of pounding of adjacent buildings under seismic excitations. It should be recognized that the evaluation of the critical separation distance is a one-sided barrier crossing problem while the problem of structural design under seismic excitations is a two-sided crossing problem. A procedure for assessing the required separation distance with or without considering possible uncertainty in structural properties was presented based on the reliability methods and random vibration theory. The procedure was used to carry out parametric analyses. It is shown that use of the complete quadratic combination (CQC) rule with the modal responses employed for designing structures may over- or underestimate the critical separation distance, depending on the damping ratios and the closeness of the natural vibration periods of adjacent buildings. This is due to not only one-sided versus two-sided crossing problem but also the approximation in the CQC rule. Further, the effect of the uncertainty in structural properties on the estimated separation is investigated. The results indicate that this uncertainty tends to increase the required critical separation distance.     

Delay-insensitive codes — an overview

The problem of delay-insensitive data communication is described. The notion of delay-insensitive code is defined, giving precise conditions under which delay-insensitive data communication is feasible. Examples of these codes are presented and analyzed. It appears that delay-insensitive codes are equivalent with antichains in partially ordered sets and with all unidirectional error-detecting codes. Tom Verhoeff received the B.S. and M.S. degrees in mathematics from Eindhoven University of Technology, The Netherlands, in 1985. He is currently an Assistant Professor at the Department of Mathematics and Computing Science of the same university. His main research interests are parallel computations, especially formalisms for their specification and design, and their implementation as delay-insensitive VLSI circuits.     

河南油田潜油电泵井远程无线监控系统研制

针对河南油田研制了一种潜油电泵井远程无线监控系统。详细介绍了该系统的软硬件组成及工作原理。系统研制的主要内容包括：数据及指令传输监控软件的开发。利用SQL Server实现相关数据的管理和实时数据的网络广播；该系统在河南油田建成后．缩短了开井周期。减轻了人工劳动强度，提高了采油效率。实现了电泵井的现代化管理。     

基于Pro/ENGINEER链传动运动仿真

介绍了Pro/ENGINEER 2001的Pro/MECHANICA模块,提出了一种基于Pro/ENGI-NEER建立链传动运动模型的一般方法,对运动的模型进行简化并阐述了零件、组件的建立到运动模型建立和运动仿真的完成.同时,也提出了链传动运动模型建立的技巧.     

管线油电损耗的灰色模型及预测

对于管道运输来说，影响输油成本变化的因素有很多，但是对总成本影响最大的是油电损耗费用。由于来自现场的输量和相关参数样本数据不足，只知道连续几年的流量、油电损耗，要预测将来每年的油电损耗，经典经济数学不能满足这样的研究。然而灰色系统理论要求的研究样本较少，只要知道连续几年的流量、油电损耗，就能预测将来每年的油电损耗，估算其输油成本，且模型精度较高。利用灰色系统理论，以输油管线每年的输量、相应的电耗和油耗为时间序列，建立了三元素非等间距GM(1，1)模型，该模型为预测管线年输油成本提供了可靠的依据。     

两种含水炸药动压下减敏作用的实验研究

用实验方法对两种含水炸药—水胶炸药和珍珠岩敏化的乳化炸药动压下的减敏作用进行了研究。为了更全面深入地研究这问题,提出了临界压死距离和临界距离两个概念。研究表明,含水炸药的减敏作用与药包间距和延期时差关系很大。水胶炸药的临界压死距离大于乳化炸药,而它们的临界距离相当,这表明两种炸药发生减敏的难易程度相近,但是乳化炸药的抗压死能力比水胶炸药大。采用5段延期电雷管引爆时两种含水炸药的减敏作用比采用2段延期电雷管引爆严重些。     

Improvement on threshold proxy signcryption scheme

Signcryption is a public key or asymmetric cryptographic method that provides simultaneously both message confidentiality and integrity at a lower computational and communication cost. This paper presents a （t, n） threshold proxy signcryption scheme in which no less than t proxy agents in the proxy group can produce the signcryption cryptogram. combines the functionality of threshold proxy signing and encryption. The proposed scheme combines the functionality of both threshold proxy signing and encryption, and provides fair protection for the sender and the proxy agents. This scheme is secure against attack of public key substitution. It also satisfies security properties such as confidentiality and authenticity.