Scheduling and lot streaming in two‐machine open shops with no‐wait in process

We study the problem of minimizing the makespan in no‐wait two‐machine open shops producing multiple products using lot streaming. In no‐wait open shop scheduling, sublot sizes are necessarily consistent; i.e., they remain the same over all machines. This intractable problem requires finding sublot sizes, a product sequence for each machine, and a machine sequence for each product. We develop a dynamic programming algorithm to generate all the dominant schedule profiles for each product that are required to formulate the open shop problem as a generalized traveling salesman problem. This problem is equivalent to a classical traveling salesman problem with a pseudopolynomial number of cities. We develop and test a computationally efficient heuristic for the open shop problem. Our results indicate that solutions can quickly be found for two machine open shops with up to 50 products. © 2005 Wiley Periodicals, Inc. Naval Research Logistics, 2005     

我国钢结构耐火设计方法评述

分析并指出了我国现行钢结构耐火设计方法的缺点,建议采用性能化设计方法以提高钢结构耐火设计的可靠度。     

基于B/S的开放式基础实验教学系统设计

采用B/S模式和ASP技术,对基础实验教学系统进行了全新的设计,这种设计对强化基础实验教学的效果与质量将起到积极和有益的作用。     

建筑中庭排烟性能化设计与分析

采用火灾烟气控制工程计算方法,设定较适合的火灾场景,对某中庭建筑排烟方式进行性能化分析,得出采取自然排烟方式的可行性建议,并确定了排烟设备的选型、数量和控制方式。     

Single machine parallel batch scheduling subject to precedence constraints

We consider the single machine parallel batch scheduling problems to minimize makespan and total completion time, respectively, under precedence relations. The complexities of these two problems are reported as open in the literature. In this paper, we settle these open questions by showing that both problems are strongly NP‐hard, even when the precedence relations are chains. When the processing times of jobs are directly agreeable or inversely agreeable with the precedence relations, there is an O(n²) time algorithm to minimize the makespan. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2004     

可变落点的再入机动飞行器姿控系统设计

基于选择的姿态反馈控制系统结构,从姿控系统稳定性能提高的角度,设计了控制系统反馈参数,以适应可变落点引起的飞行器参数变化。通过机动飞行器的六自由度飞行弹道仿真,表明所设计的姿态反馈控制系统控制效果较好,可适应预定区域内的飞行落点变化要求。     

Predicting intensive care unit bed occupancy for integrated operating room scheduling via neural networks

In a master surgery scheduling (MSS) problem, a hospital's operating room (OR) capacity is assigned to different medical specialties. This task is critical since the risk of assigning too much or too little OR time to a specialty is associated with overtime or deficit hours of the staff, deferral or delay of surgeries, and unsatisfied—or even endangered—patients. Most MSS approaches in the literature focus only on the OR while neglecting the impact on downstream units or reflect a simplified version of the real‐world situation. We present the first prediction model for the integrated OR scheduling problem based on machine learning. Our three‐step approach focuses on the intensive care unit (ICU) and reflects elective and urgent patients, inpatients and outpatients, and all possible paths through the hospital. We provide an empirical evaluation of our method with surgery data for Universitätsklinikum Augsburg, a German tertiary care hospital with 1700 beds. We show that our model outperforms a state‐of‐the‐art model by 43% in number of predicted beds. Our model can be used as supporting tool for hospital managers or incorporated in an optimization model. Eventually, we provide guidance to support hospital managers in scheduling surgeries more efficiently.     

面向概念设计的虚拟原型描述模型与语言

针对概念设计的特点以及虚拟原型的特征分类 ,提出了基于虚拟原型的概念设计模型V -desModel及其描述语言VPML ,其核心是利用产品视图模型描述设计对象 ,将虚拟特征概念融入视图模型中 ,并采用可扩展“三维实体 -约束图”描述设计对象之间的约束关系。V -desModel模型和VPML语言能有效地支持基于虚拟原型的概念设计过程 ,较好地解决了概念设计中产品虚拟原型的逼真性要求和设计信息不完备之间的矛盾 ,为多领域系统在概念设计阶段的协同设计、并行设计及联合仿真过程提供一致的模型描述     

战车火控外弹道实时解算的研究

论证了战车火控系统弹道实时解算技术的现状和发展 ,提出了现代火控弹道问题实时解算的新的数学模型。这一先进的弹道解算设计方法 ,适应于计算机运算速度已大幅提高的技术水平 ,具有高度通用化的特点 ,并且使弹道问题的解算可以完全脱离射表进行     

基于遗传算法的通信网络可靠性优化设计

在可靠性条件约束下 ,使网络成本最低是网络规划NP hard问题 .文章提出一种基于遗传算法的优化方法解决了这类问题 .仿真结果表明这种算法是有效的 .