水下拖曳系统数值仿真方法研究

总结了拖曳系统运动仿真数值模拟方法的类型及各自的优缺点,以有限差分法为例对其建模方法进行了阐述,并将计算结果与试验结果进行了比对。     

Significantly enhanced charge conduction in electric double layer capacitors using carbon nanotube-grafted activated carbon electrodes

Carbon nanotube (CNT)-grafting by chemical vapor deposition was conducted to reduce the resistance of activated carbon fiber serving as an electrode for electric double layer capacitors. Sputtering deposition of Ni catalyst particles led to a uniform growth of CNTs on the carbon fiber surface through the tip-growth mechanism. Because sputtering deposition ensures little pore blockage (in comparison with wet-impregnation), the surface area decrease of the carbon fiber due to Ni loading was minimized. By using H₂SO₄ aqueous solution as the electrolyte, a capacitor cell assembled with the CNT-grafted fiber showed higher electron and electrolyte-ion conductivities relative to a cell assembled with the bare fiber. By increasing the discharging current density from 1 to 150 mA cm⁻², the bare fiber exhibited a capacitance loss of 17% while the CNT-grafted fiber showed a mitigated capacitance loss of only 7%. This developed CNT-grafting technique renders activated carbon fiber a promising electrode material for a variety of electrochemical applications.     

Boundedness and stability for nonautonomous bidirectional associative neural networks with delay

The paper studies the nonautonomous bidirectional associative neural networks systems with time-varying delays. By applying Lyapunov functional method, introducing many parameters, and combining this with the techniques of inequality analysis, a series of criteria of the uniform ultimate boundedness, global exponential stability, and the existence of periodic solutions are obtained. The results obtained in this paper are new and useful.     

电信转型的回顾和思考

本文首先阐述电信运营企业转型的内外推动力和意义所在,提出持续创新是转型的根本解决之道,然后分别就业务应用、网络技术、运营模式以及企业管理等几个主要方面的转型方案进行探讨并提出了若干解决思路,最后阐明电信转型的长期性、系统性以及创新性。     

动能拦截导弹弹道数据计算研究

动能拦截弹脱靶量要求为零,其杀伤目标为近地轨道运行的弹道导弹和低轨卫星等,目标运行速度极快,与其它类型导弹相比,动能拦截弹的弹道计算精度要求更高。针对这一问题,介绍了动能拦截弹的拦截段弹道数学模型,分析了弹道数据计算流程,将诸元解算转化为方位角和程序角的计算问题,采用计算精度较高的积分算法,得到了导弹拦截过程的弹道数据,仿真表明,导弹数据计算精度满足作战仿真要求。     

基于IPv6校园网的智能选课系统的J2EE架构的设计与实现

通过分析IPv6校园网自主学习模式下的自主选课问题,提出了利用J2EE技术构建基于IPv6校园网的智能选课系统的总体结构及具体实现.     

大规模多业务网络中几个关键问题的分析

随着网络规模的不断扩大和业务的不断涌现，一些在网络建设初期没有予以足够重视的问题已日益变得突出。文章针对其中几个关键问题进行了分析，并提出了解决思路。     

A Built-in Self-Test Scheme with Diagnostics Support for Embedded SRAM

In this paper we propose a novel built-in self-test (BIST) design for embedded SRAM cores. Our contribution includes a compact and efficient BIST circuit with diagnosis support and an automatic diagnostic system. The diagnosis module of our BIST circuit can capture the error syndromes as well as fault locations for the purposes of repair and fault/failure analysis. In addition, our design provides programmability for custom March algorithms with lower hardware cost. The combination of the on-line programming mode and diagnostic system dramatically reduces the effort in design debugging and yield enhancement. We have designed and implemented test chips with our BIST design. Experimental results show that the area overhead of the proposed BIST design is only 2.4% for a 128 KB SRAM, and 0.65% for a 2 MB one.     

Information technology innovations: general diffusion patterns andits relationships to innovation characteristics

While many scholars of organizational innovations have examined characteristics of innovations such as relative advantage and complexity and how they facilitate the adoption of an innovation by organizations, others have used mathematical models to fit diffusion patterns. In this study, the authors attempt to integrate these two areas of inquiry and explore the possibilities to predict diffusion patterns based on characteristics of the innovation and the adopting entities. Based on a cross-sectional sample of 313 large American firms, 20 information technology (IT) innovations were examined and their diffusion patterns assessed with respect to models that espoused internal and external influence. The mixed influence model (Bass model) was chosen as a robust common representation for the set of diffusion patterns. However, the external influence as represented by the coefficient of innovation was found to be extremely small and the internal influence dominates for all innovations. The other two parameters of the model, the saturation level and the coefficient of imitation, which represents internal influence, were then used to perform a cluster analysis. Five clusters of technologies emerged, and the potential relationships between their innovation characteristics and diffusion patterns were explored. Rigorous examination of these potential relationships by future researchers may result in practical methods for predicting patterns of IT innovation diffusion based on innovation and technology characteristics     

采用信息融合技术的IR／MMW复合导引头的目标跟踪

从误差测量环节入手，基于IR／MMW双模结构，采用信息融合处理技术提高其估计跟踪精度，最终达到降低制导误差，提高武器性能的目的，仿真结果验证了该方法的有效性。