知识经济与计算机教育改革

随着人类社会的进步和科学技术的迅猛发展,人类正面临着由物质经济向知识经济转变的历史时期,高新技术正深刻地影响着经济发展、社会进步和人类一切活动。本文就知识经济和信息产业对计算机科学与技术教育的挑战和我们如何把握机遇,深化教学改革,培养适应二十一世纪需要的高质量的信息技术人才,谈谈自己的认识和看法。     

战术地地导弹打击复杂飞机跑道的火力运用

在文献 [1,2 ,3]的基础上 ,研究了运用战术地地导弹对复杂飞机跑道实施打击中 ,最优瞄准点选择和毁伤效果指标计算原理和步骤 ,给出了描述复杂飞机跑道失效率的毁伤指标体系和内涵     

用于目标弱信号处理的三重相关匹配滤波技术

分析了在二重相关匹配滤波技术的基础上实现三重相关匹配滤波的方法。三重相关匹配滤波对于目标的弱信号进行检测和处理 ,具有广泛的实用价值。给出了一个红外搜索目标信号处理的计算机模拟结果 ,并对计算机模拟结果进行了分析 ,证明了三重相关匹配滤波技术相对于二重相关和三重相关检测技术的优越性     

地空导弹与弹道导弹的技术融合正在促使这两类导弹产生突破性的发展

地空导弹采用弹道导弹的抛物弹道技术 ,能够实现应用固体推进剂达到低质量远射程的目标。弹道导弹采用地空导弹末段弹道的寻的制导控制技术 ,可以达到降速、增程并实现末段有效制导控制和弹道机动的目标 ,从而大幅度提高命中精度和突防概率。地空导弹和弹道导弹之间的技术融合 ,已经开始并将很快形成这两类导弹的新一轮突破性的发展     

基于单片机的远程光纤通信在点对点安全验证系统上的应用

现有的点对点安全验证系统都是基于电缆连接实现系统信息传输的。电缆传输信号存在传输衰减大、抗干扰能力差、在雷暴天气易发生事故等缺点。通过将基于单片机89C2051的远程光纤通信应用到现有设备来改进控制信号的传输模式,将电信号转换为光信号,在数据传输中使用传输同步码加密、数据包CRC校验、串行数据编码以及光纤连通性定时自动监测等技术,可以从物理信号传输到数据接收处理的整个过程中保证系统的安全性和可靠性;同时,通过光纤通信方案,也能节省系统构建和维护的经费。     

Dynamic coordination of production planning and sales admission control in the presence of a spot market

We consider the decision‐making problem of dynamically scheduling the production of a single make‐to stock (MTS) product in connection with the product's concurrent sales in a spot market and a long‐term supply channel. The spot market is run by a business to business (B2B) online exchange, whereas the long‐term channel is established by a structured contract. The product's price in the spot market is exogenous, evolves as a continuous time Markov chain, and affects demand, which arrives sequentially as a Markov‐modulated Poisson process (MMPP). The manufacturer is obliged to fulfill demand in the long‐term channel, but is able to rein in sales in the spot market. This is a significant strategic decision for a manufacturer in entering a favorable contract. The profitability of the contract must be evaluated by optimal performance. The current problem, therefore, arises as a prerequisite to exploring contracting strategies. We reveal that the optimal strategy of coordinating production and sales is structured by the spot price dependent on the base stock and sell‐down thresholds. Moreover, we can exploit the structural properties of the optimal strategy to conceive an efficient algorithm. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

Optimal control of a production‐inventory system with both backorders and lost sales

We consider the optimal control of a production inventory‐system with a single product and two customer classes where items are produced one unit at a time. Upon arrival, customer orders can be fulfilled from existing inventory, if there is any, backordered, or rejected. The two classes are differentiated by their backorder and lost sales costs. At each decision epoch, we must determine whether or not to produce an item and if so, whether to use this item to increase inventory or to reduce backlog. At each decision epoch, we must also determine whether or not to satisfy demand from a particular class (should one arise), backorder it, or reject it. In doing so, we must balance inventory holding costs against the costs of backordering and lost sales. We formulate the problem as a Markov decision process and use it to characterize the structure of the optimal policy. We show that the optimal policy can be described by three state‐dependent thresholds: a production base‐stock level and two order‐admission levels, one for each class. The production base‐stock level determines when production takes place and how to allocate items that are produced. This base‐stock level also determines when orders from the class with the lower shortage costs (Class 2) are backordered and not fulfilled from inventory. The order‐admission levels determine when orders should be rejected. We show that the threshold levels are monotonic (either nonincreasing or nondecreasing) in the backorder level of Class 2. We also characterize analytically the sensitivity of these thresholds to the various cost parameters. Using numerical results, we compare the performance of the optimal policy against several heuristics and show that those that do not allow for the possibility of both backordering and rejecting orders can perform poorly.© 2010 Wiley Periodicals, Inc. Naval Research Logistics 2010     

高超声速滑翔式再入飞行器最大航程飞行轨迹分析

针对航程最大的再入问题,研究了高超声速滑翔式再入飞行器的飞行轨迹特性.使用Legendre伪谱法进行轨迹优化,得到最优轨迹.分析了路径约束对轨迹的影响,以及在路径约束下控制量对飞行轨迹的影响.根据控制量的取值规律,提出一种升力系数的分段直线取值模型.数字仿真表明,通过该模型得到的飞行轨迹与最优轨迹类似,且航程相差很小,可以作为一种使航程最大的轨迹控制方法.     

改革开放以来我国经济法取得的主要成效及发展方向

中国特色经济法是改革开放的产物,有力地促进了社会主义市场经济的健康、快速发展。经济法在保证经济实现科学发展的同时,自身也突破了对调整能力的传统认识,区分了经济法与行政法,明确了经济法的正确定位,创新了经济法的发展观,提出了“经济法主体”概念,冲破了公法与私法的界限,形成了与相关学科协调发展的经济法学研究格局。今后,经济法的发展必须重视从完善社会主义市场经济基本制度,健全现代市场体系,规范政府科学干预经济生活,宏观调控的重点、热点、难点问题和基础理论研究的创新上把握研究重点,保证经济实现科学发展。     

指令时延对舰空导弹中末制导交班误差影响分析

从目标作直线飞行和机动飞行两种情况出发,建立相应的舰空导弹中末制导交班时的导引头指向误差模型和导弹速度矢量指向误差模型,指出了相应的误差修正方法,进行了仿真计算,并分析了计算结果.仿真结果验证了上述模型的正确性.