挠性航天器变幅值输入成形姿态机动策略

针对变参数挠性航天器的姿态机动问题,在变幅值零振动成形器的基础上,提出了鲁棒性较强的变幅值零振动和零微分成形器设计方法,设计了鲁棒姿态机动策略.该机动策略的控制目标是,将航天器机动到期望状态的同时,消除挠性结构的残余振动.以含转动挠性太阳翼的航天器进行三轴姿态机动为例,进行数值仿真.仿真结果表明,该机动策略对挠性结构频...     

新型抗冲击、抗爆炸防护结构的研究

海湾战争、科索沃战争和伊拉克战争表明,完善的防护工程体系在高科技局部战争中具有极为重要的作用。针对目前防护工程中存在的一些问题,提出了一种新型抗冲击、抗爆炸防护结构,该防护结构以钢管混凝土短构件为基本构件,通过一定的组合方式组成一种新型的遮弹结构,由于钢管混凝土构件具有承载能力高、抗压强度大尤其是延性好的特性,因此该新型遮弹结构的抗冲击和抗爆炸能力是很强的,非常适宜在防护工程中应用。     

潜艇对机动目标跟踪和攻击若干问题的探讨

在现代作战条件下,潜艇所要跟踪和攻击的目标多数情况下应认为是机动目标。限于潜艇所载目标探测传感器和武器特点,以及潜艇自身隐蔽性、机动性方面的约束,潜艇跟踪和攻击机动目标存在许多困难和值得研究的问题。对这些问题进行了较为系统地梳理,并对其中的若干问题进行了探讨,包括目标机动的原因、机动目标可判断性问题、机动判断手段、机动判断后目标参数的处理、机动目标攻击的基本原则和方法等,还对潜艇指控系统强化机动目标跟踪和攻击功能提出了一些建议。     

实施人才强校战略 促进学校可持续发展

高等学校处于重要的发展机遇期。人才是促进学校持续、健康、协调发展的关键。以科学发展观为指导，实施人才强校战略是保证发展的重大举措。坚持开拓创新的精神和求真务实的作风，不断开创高校人才工作新局面。     

Approximations for heavily loaded G/GI/n + GI queues

Motivated by applications to service systems, we develop simple engineering approximation formulas for the steady‐state performance of heavily loaded G/GI/n+GI multiserver queues, which can have non‐Poisson and nonrenewal arrivals and non‐exponential service‐time and patience‐time distributions. The formulas are based on recently established Gaussian many‐server heavy‐traffic limits in the efficiency‐driven (ED) regime, where the traffic intensity is fixed at ρ > 1, but the approximations also apply to systems in the quality‐and‐ED regime, where ρ > 1 but ρ is close to 1. Good performance across a wide range of parameters is obtained by making heuristic refinements, the main one being truncation of the queue length and waiting time approximations to nonnegative values. Simulation experiments show that the proposed approximations are effective for large‐scale queuing systems for a significant range of the traffic intensity ρ and the abandonment rate θ, roughly for ρ > 1.02 and θ > 2.0. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 187–217, 2016     

Adaptive random search for continuous simulation optimization

We present, analyze, and compare three random search methods for solving stochastic optimization problems with uncountable feasible regions. Our adaptive search with resampling (ASR) approach is a framework for designing provably convergent algorithms that are adaptive and may consequently involve local search. The deterministic and stochastic shrinking ball (DSB and SSB) approaches are also convergent, but they are based on pure random search with the only difference being the estimator of the optimal solution [the DSB method was originally proposed and analyzed by Baumert and Smith]. The three methods use different techniques to reduce the effects of noise in the estimated objective function values. Our ASR method achieves this goal through resampling of already sampled points, whereas the DSB and SSB approaches address it by averaging observations in balls that shrink with time. We present conditions under which the three methods are convergent, both in probability and almost surely, and provide a limited computational study aimed at comparing the methods. Although further investigation is needed, our numerical results suggest that the ASR approach is promising, especially for difficult problems where the probability of identifying good solutions using pure random search is small. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

浅谈教师对数学学业不良生的影响

本文通过教师的信念、课堂教学、教师的问题意识三个方面的探讨，来论述教师对数学学业不良生的影响，希望通过教师的作用有效促进数学学业不良生的转化。     

Reliability inference for field conditions from accelerated degradation testing

Accelerated degradation testing (ADT) is usually conducted under deterministic stresses such as constant‐stress, step‐stress, and cyclic‐stress. Based on ADT data, an ADT model is developed to predict reliability under normal (field) operating conditions. In engineering applications, the “standard” approach for reliability prediction assumes that the normal operating conditions are deterministic or simply uses the mean values of the stresses while ignoring their variability. Such an approach may lead to significant prediction errors. In this paper, we extend an ADT model obtained from constant‐stress ADT experiments to predict field reliability by considering the stress variations. A case study is provided to demonstrate the proposed statistical inference procedure. The accuracy of the procedure is verified by simulation using various distributions of field stresses. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2006.     

动态疏散逃生系统研究及其应用

保证人员疏散安全是建筑防火安全设计的重要目标之一,而疏散逃生设施是疏散设施不可或缺的组成部分。分别从理念、技术和应用层面介绍动态疏散逃生系统在机场环境中的应用,该系统实现了信息化控制管理,可根据火灾实时情况动态引导人员疏散,具有语音、调整疏散路径、光流等特点,实现＂安全、准确、迅速＂地引导人员避烟逃生,较以往应急疏散指示灯具具有更高的可靠性和安全性。     

单星定向原理及GPS仿真试验

介绍了一种新的卫星定向方法,该方法仅利用一颗地球静止轨道卫星完成定向;介绍了利用GPS卫星进行单星定向原理验证试验的方法、条件和结果。试验结果表明,对于3m长基线,单星定向精度可达0.05°。从而说明利用一颗地球静止轨道卫星进行定向,在原理上是正确可行的。