虚拟环境中视景的表示与生成

虚拟现实(Virtual Reality:VR)的飞速发展和PC机的广泛使用提出了基于PC的VR应用要求,视景的表示与生成是VR环境的基础与核心。文中介绍采用面向对象机制,在PC机上基于MFC和OpenGL实现的虚拟环境中视景表示与生成的方法。用该方法生成的视景具有良好的视觉效果。     

超精密金刚石车床伺服进给数学模型

首先分析了车床进给系统各环节的传递函数,在此基础上采用频域估计建模和时域建模方法建立了车床伺服进给系统的Ｓ域和Ｚ域模型     

基于神经网络的超精密机床伺服进给非线性模型辨识

以双轴Ｔ型结构的超精密金刚石车床的伺服进给系统为研究对象,采用自构造神经网络技术,建立了系统的非线性动态数学模型,为系统非线性控制与补偿提供参考模型     

机枪浮动技术研究

介绍了一种环形弹簧浮动机在大口径机枪上实现的可能性,说明了采用环形弹簧可以使大口径机枪获得浮动。建立了武器系统的动力学模型和目标函数,用优化设计的方法确定了环形弹簧的设计参数,并对某型高射机枪进行了动力分析。     

一种对间歇采样转发干扰的识别新方法

间歇采样转发干扰是一种针对相干雷达的有效干扰样式,该类干扰的抑制技术研究需求迫切,而干扰识别历来是抗干扰流程中的关键环节,针对间歇采样转发干扰的识别问题,提出了一种基于关联维数的干扰识别方法。通过对3类间歇采样转发干扰信号进行傅里叶变换,挖掘信号频谱上的差异,提取频域关联维数作为干扰识别的特征参数,并利用支持向量机进行分类识别,为后续雷达系统采取针对性抗干扰措施提供重要的决策信息。仿真结果证明该方法具有较高的识别率。     

A note on combined job selection and sequencing problems

We investigate the solvability of two single‐machine scheduling problems when the objective is to identify among all job subsets with cardinality k,1≤k≤n, the one that has the minimum objective function value. For the single‐machine minimum maximum lateness problem, we conclude that the problem is solvable in O(n²) time using the proposed REMOVE algorithm. This algorithm can also be used as an alternative to Moore's algorithm to solve the minimum number of tardy jobs problem by actually solving the hierarchical problem in which the objective is to minimize the maximum lateness subject to the minimum number of tardy jobs. We then show that the REMOVE algorithm cannot be used to solve the general case of the single‐machine total‐weighted completion time problem; we derive sufficient conditions among the job parameters so that the total weighted completion time problem becomes solvable in O(n²) time. © 2013 Wiley Periodicals, Inc. Naval Research Logistics 60: 449–453, 2013     

全气动步兵武器表层自动喷涂机设计

分析目前步兵武器零件表层喷涂技术现状,提出全气动自动喷涂机设计方案,根据步兵武器零件结构特点,规划自动喷涂轨迹,设计全气动自动化喷涂专用设备．该设备具有本质安全性,适于部队条件下使用．     

基于CPLD与单片机的多路高精度数据采集系统设计

结合CPLD与单片机设计了一种多路高精度数据采集系统,最高可达24位转换精度。所采集数据具备良好的实时性,可采集通道数目多,同时系统具备较强的抗外界干扰能力,结构简单,可靠性好。该系统具有较强的可移植性,能够广泛应用于多路、高精度、低频数据采集的场合。     

A m‐parallel crane scheduling problem with a non‐crossing constraint

In this paper, we study a m‐parallel machine scheduling problem with a non‐crossing constraint motivated by crane scheduling in ports. We decompose the problem to allow time allocations to be determined once crane assignments are known and construct a backtracking search scheme that manipulates domain reduction and pruning strategies. Simple approximation heuristics are developed, one of which guarantees solutions to be at most two times the optimum. For large‐scale problems, a simulated annealing heuristic that uses random neighborhood generation is provided. Computational experiments are conducted to test the algorithms. © 2006 Wiley Periodicals, Inc. Naval Research Logistics, 2007.     

On equivalence between the proportionate flow shop and single‐machine scheduling problems

We derive sufficient conditions which, when satisfied, guarantee that an optimal solution for a single‐machine scheduling problem is also optimal for the corresponding proportionate flow shop scheduling problem. We then utilize these sufficient conditions to show the solvability in polynomial time of numerous proportionate flow shop scheduling problems with fixed job processing times, position‐dependent job processing times, controllable job processing times, and also problems with job rejection. © 2015 Wiley Periodicals, Inc. Naval Research Logistics 62: 595–603, 2015