大学英语教学中自主学习能力的培养

自主学习能力是当今信息时代人们为适应社会发展所必须具备的一种能力。要深刻理解自主学习的内涵、自主学习的理论基础、自主学习的必要性和可行性,探讨在我国当前的教育环境下培养学生自主学习能力的途径,教师在教学过程中应注重学生自主学习能力的培养,更好地发挥其指导者、组织者的作用。敦促学生充分发挥其主观能动性,积极参与教学过程,提高他们的英语综合应用能力和自主学习能力。     

防空导弹网络化作战C4ISR系统体系结构研究

网络中心战是信息化战争中一种新的作战概念.按照网络中心战的概念,研究防空导弹网络化作战的C4ISR体系结构.提出了以火力单元的功能系统为基本单元,建立跟踪制导网、指挥控制网和拦截兵器网三层逻辑网结构,并定义各逻辑层的主要功能和基本组成.该结构对实现防空导弹网络中心战有指导意义.     

Assessing the value of demand sharing in supply chains

We consider the problem of assessing the value of demand sharing in a multistage supply chain in which the retailer observes stationary autoregressive moving average demand with Gaussian white noise (shocks). Similar to previous research, we assume each supply chain player constructs its best linear forecast of the leadtime demand and uses it to determine the order quantity via a periodic review myopic order‐up‐to policy. We demonstrate how a typical supply chain player can determine the extent of its available information in the presence of demand sharing by studying the properties of the moving average polynomials of adjacent supply chain players. The retailer's demand is driven by the random shocks appearing in the autoregressive moving average representation for its demand. Under the assumptions we will make in this article, to the retailer, knowing the shock information is equivalent to knowing the demand process (assuming that the model parameters are also known). Thus (in the event of sharing) the retailer's demand sequence and shock sequence would contain the same information to the retailer's supplier. We will show that, once we consider the dynamics of demand propagation further up the chain, it may be that a player's demand and shock sequences will contain different levels of information for an upstream player. Hence, we study how a player can determine its available information under demand sharing, and use this information to forecast leadtime demand. We characterize the value of demand sharing for a typical supply chain player. Furthermore, we show conditions under which (i) it is equivalent to no sharing, (ii) it is equivalent to full information shock sharing, and (iii) it is intermediate in value to the two previously described arrangements. Although it follows from existing literature that demand sharing is equivalent to full information shock sharing between a retailer and supplier, we demonstrate and characterize when this result does not generalize to upstream supply chain players. We then show that demand propagates through a supply chain where any player may share nothing, its demand, or its full information shocks (FIS) with an adjacent upstream player as quasi‐ARMA in—quasi‐ARMA out. We also provide a convenient form for the propagation of demand in a supply chain that will lend itself to future research applications. © 2014 Wiley Periodicals, Inc. Naval Research Logistics 61: 515–531, 2014     

Multi‐period maintenance scheduling of tree networks with minimum flow disruption

We introduce a multi‐period tree network maintenance scheduling model and investigate the effect of maintenance capacity restrictions on traffic/information flow interruptions. Network maintenance refers to activities that are performed to keep a network operational. For linear networks with uniform flow between every pair of nodes, we devise a polynomial‐time combinatorial algorithm that minimizes flow disruption. The spiral structure of the optimal maintenance schedule sheds insights into general network maintenance scheduling. The maintenance problem on linear networks with a general flow structure is strongly NP‐hard. We formulate this problem as a linear integer program, derive strong valid inequalities, and conduct a polyhedral study of the formulation. Polyhedral analysis shows that the relaxation of our linear network formulation is tight when capacities and flows are uniform. The linear network formulation is then extended to an integer program for solving the tree network maintenance scheduling problem. Preliminary computations indicate that the strengthened formulations can solve reasonably sized problems on tree networks and that the intuitions gained from the uniform flow case continue to hold in general settings. Finally, we extend the approach to directed networks and to maintenance of network nodes. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

作战指挥隐蔽性指标定量评估方法研究

作战指挥的隐蔽性是影响现代战争胜负的重要因素之一,针对作战指挥隐蔽性的特征,运用概率论建模理论探讨指挥隐蔽性指标的定量评估问题。定义了影响作战指挥隐蔽性因素的概率模型,以作战情报系统的3种不同状态为基础,建立了各系统状态的隐蔽性方程。通过模拟战场指挥过程,得到了不同条件下的作战系统隐蔽性概率,为改善指挥员的指挥方式提供了良好的理论参考意见,该理论对提高海军部队作战指挥效能具有参考价值。     

基于效果的炮兵行动C2系统动力学建模与仿真

一体化联合作战参战军兵种多、指挥控制(C2)与协调复杂。围绕炮兵行动特点要求,运用系统动力学理论建立联合作战炮兵行动指挥控制的系统动力学模型,研究常规打击和基于效果作战两种指挥控制模式下炮兵行动所产生的不同结果及其原因,并给合作战想定仿真验证,得出较为可靠的结论,为解决联合作战炮兵行动精确指挥控制与协调提供一种有效途径     

Analysis of algorithms for two‐stage flowshops with multi‐processor task flexibility

In this article we introduce a 2‐machine flowshop with processing flexibility. Two processing modes are available for each task: namely, processing by the designated processor, and processing simultaneously by both processors. The objective studied is makespan minimization. This production environment is encountered in repetitive manufacturing shops equipped with processors that have the flexibility to execute orders either individually or in coordination. In the latter case, the product designer exploits processing synergies between two processors so as to execute a particular task much faster than a dedicated processor. This type of flowshop environment is also encountered in labor‐intensive assembly lines where products moving downstream can be processed either in the designated assembly stations or by pulling together the work teams of adjacent stations. This scheduling problem requires determining the mode of operation of each task, and the subsequent scheduling that preserves the flowshop constraints. We show that the problem is ordinary NP‐complete and obtain an optimal solution using a dynamic programming algorithm with considerable computational requirements for medium and large problems. Then, we present a number of dynamic programming relaxations and analyze their worst‐case error performance. Finally, we present a polynomial time heuristic with worst‐case error performance comparable to that of the dynamic programming relaxations. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2004.     

GPU上高光谱快速ICA降维并行算法

高光谱影像降维快速独立成分分析过程包含大规模矩阵运算和大量迭代计算。通过分析算法热点,设计协方差矩阵计算、白化处理、ICA迭代和IC变换等关键热点的图像处理单元映射方案,提出并实现一种G-Fast ICA并行算法,并基于GPU架构研究算法优化策略。实验结果显示:在处理高光谱影像降维时,CPU/GPU异构系统能获得比CPU更高效的性能,G-Fast ICA算法比串行最高可获得72倍加速比,比16核CPU并行处理快4~6.5倍。     

独立分量分析在雷达盲信号处理上的应用

独立分量分析(ICA)是近年来发展起来的一种有效的雷达盲信源分离方法。目前新体制雷达的大量涌现,运用原有的雷达分选方法是无法分选的,这已经无法适应现代复杂的电磁环境。在深入分析FastICA算法的基础上,将其应用于连续波雷达信号分选中。计算机仿真表明,这种算法应用于连续波雷达盲信号分选时,不仅提高了信号的分选速度和信号分离的准确率,而且可以有效地提高信号分选的效能,也为盲信号处理提供了一种新的思路。     

Single‐commodity stochastic network design under demand and topological uncertainties with insufficient data

Stochastic network design is fundamental to transportation and logistic problems in practice, yet faces new modeling and computational challenges resulted from heterogeneous sources of uncertainties and their unknown distributions given limited data. In this article, we design arcs in a network to optimize the cost of single‐commodity flows under random demand and arc disruptions. We minimize the network design cost plus cost associated with network performance under uncertainty evaluated by two schemes. The first scheme restricts demand and arc capacities in budgeted uncertainty sets and minimizes the worst‐case cost of supply generation and network flows for any possible realizations. The second scheme generates a finite set of samples from statistical information (e.g., moments) of data and minimizes the expected cost of supplies and flows, for which we bound the worst‐case cost using budgeted uncertainty sets. We develop cutting‐plane algorithms for solving the mixed‐integer nonlinear programming reformulations of the problem under the two schemes. We compare the computational efficacy of different approaches and analyze the results by testing diverse instances of random and real‐world networks. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 154–173, 2017