CDMA网络中的综合业务接入策略*

为了解决CDMA网络中综合业务的协调传输问题,提出了资源竞争的策略。通过非实时类业务和实时类业务的分析,在考虑业务群体的Logistic变化规律的基础上,以总体QoS效果为追求目标,推导出竞争平衡方程。实验表明了该模型能够提高系统的整体容量。     

一体化水下航行器仿真系统软件设计

文章研究了水下自动航行器仿真系统的一体化软件设计原则和方法,给出了仿真系统的软件结构及其关键的设计技术。     

A medical hand tool physical interaction evaluation approach for prototype testing using patient care simulators

The purpose of this study was to develop and test a physical ergonomics assessment approach for medical device handles. The method assesses wrist posture and force of exertion simultaneously by task element. Electrogoniometers and EMG sensors were connected through a data acquisition module for synchronization with video recordings of trials. Task analysis of video recordings were performed offline with Observer XT software. Average posture and force data across several repetitions of individual task elements were calculated and presented in a format suitable for informing product designers of specific issues during a test trial. A handle comfort questionnaire is proposed to survey subjective responses. The evaluation approach was applied to an endoscope needle in sampling a biopsy from the stomach wall using a gastrointestinal track simulator with ten physician surrogates. The results showed that for all task elements the wrist was in extension (33(°)-45(°)). Peak muscle forces ranged from 28% to 68% MVC across the three muscles studied. Muscle peak forces were above ACGIH HAL maximum threshold limits for four of the seven task elements, and above the action limit for all seven task elements for two muscles. The handle comfort questionnaire data also supported the high muscle force findings, and also on force distribution on the handle due to contact stresses. This combined approach could be used to collect and report detailed early stage ergonomics data from user trials on patient care simulators. The approach is proposed for use by medical device designers at the design stage of new products using prototypes, but it could also be used on existing products with real patients.     

Fuzzy parametric programming model for multi-objective integrated solid waste management under uncertainty

Solid waste management is increasingly becoming a challenging task for the municipal authorities due to increasing waste quantities, changing waste composition, decreasing land availability for waste disposal sites and increasing awareness about the environmental risk associated with the waste management facilities. The present study focuses on the optimum selection of the treatment and disposal facilities, their capacity planning and waste allocation under uncertainty associated with the long-term planning for solid waste management. The fuzzy parametric programming model is based on a multi-objective, multi-period system for integrated planning for solid waste management. The model dynamically locates the facilities and allocates the waste considering fuzzy waste quantity and capacity of waste management facility. The model addresses uncertainty in waste quantity as well as uncertainties in the operating capacities of waste management facilities simultaneously. It was observed that uncertainty in waste quantity is likely to affect the planning for waste treatment/disposal facilities more as compared with the uncertainty in the capacities of the waste management facilities. The relationship between increase in waste quantity and increase in the total cost/risk involved in waste management is found to be nonlinear. Therefore, it is possible that a marginal change in waste quantity could increase the total cost/risk substantially. The information obtained from the analysis of modeling results can be effectively used for understanding the effect of changing the priorities and objectives of planning decisions on facility selections and waste diversions.     

Variable neighborhood search for the inventory routing and scheduling problem in a supply chain

The inventory, routing and scheduling decisions are three major driving factors for supply chain performance. Since they are related to one another in a supply chain, they should be determined simultaneously to improve the decision quality. In the past, the inventory policy, vehicle routing and vehicle scheduling are determined sequentially and separately. Hence, the total cost (inventory, routing and vehicle costs) would increase. In this paper, an integrated model for the inventory routing and scheduling problem (IRSP) is proposed. Since searching for the optimal solution for this model is a non-polynomial (NP) problem, a metaheuristic, variable neighborhood search (VNS), is proposed. The proposed method was compared with other existing methods. The experimental results indicate that the proposed method is better than other methods in terms of average cost per day.     

汽包水位温压补偿控制系统研究和应用

对汽包双室平衡容器水位温压补偿控制系统进行了探讨和研究,根据温压补偿模型,分析了P L C系统难以独立实现的原因以及查表法的缺陷,提出了P L C系统与上位机系统相结合的水位温压实时连续补偿的综合控制策略,提出并分析比较了三种体系结构及其实现原理和技术,工程应用结果表明该控制系统提高了水位控制的实时性、稳定性、准确性和安全性。     

城市排污系统对河流水质影响的仿真研究

以城市废水系统的集成化管理为出发点，基于国际水协会河流水质1号模型(RWOMI)，确定了适合仿真与实时控制的简化的动态河流水质模型，在MATLAB仿真环境下建立了一个以河流为核心的集成化城市废水系统的简单仿真环境。以某河流城区段为背景，采用国际水协会发布的污水负荷和组分数据作为原始输入，模拟了排水管网和污水处理厂在不同运行条件下引起的河流水质的变化情况。仿真结果表明排水管网组合下水溢流和污水处理厂排放物的处理程度对河流水质会产生直接影响，为集成化管理提供了依据。     

基于UML/APN集成建模技术的ISCM模型研究

以集成供应链管理(ISCM)软件开发项目为研究背景，阐述UML与智能Petri网(APN)相结合的集成建模方法。首先用UML方法构建ISCM库存系统的结构模型和行为模型，用APN方法构建库存系统的Petri网模型；然后用模拟仿真器模拟验证APN模型，进而用APN模型来优化完善UML对象模型；最后用OOPL实现经模拟验证与优化的目标模型。所提出的集成建模方法和研究模型在ISCM软件产品开发中取得了良好的效果。