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。     

基于数据仓库的集成质量决策支持系统的研究

论文讨论了数据仓库的基本原理,包括数据仓库的概念、功能、特点、逻辑结构和物理结构以及数据仓库系统,集成质量系统的内涵和质量决策支持系统的决策范围,提出了基于数据仓库的集成质量决策支持系统的体系结构及其开发流程和开发的关键技术。     

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.     

分类树方法在集成电路设计功能验证中的应用

功能验证是制约集成电路设计发展的主要瓶颈,针对功能验证中存在的测试集设计难度大及覆盖模型精度低等问题,提出一种基于分类树方法的高效测试集生成方法及功能覆盖模型搭建方法,将验证方法应用于模加/模减单元的功能验证中。结果证明,运用分类树方法管理测试向量和搭建覆盖模型,可以显著提高验证完备性和可靠性。     

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。     

应用于离子注入的RFQ加速器

射频四极场(Radio frequency quodrupole,RFQ)加速器是一种非常适于用作MeV级能量离子注入的加速器.它具有束流强、体积小、使用方便、离子源处在地电位,还可同时加速正、负两种离子等优点.本文介绍了RFQ加速器在国际上的发展状况及其基本原理、北京大学研制的1 MeV RFQ加速器的具体结构、性能以及一种新型RFQ-SFRFQ组合加速器的特点.