计算机专用实时母系统在VAX／VMS环境下的实现

“母系统—子系统”的工作方式是计算机专用实时系统研制中的一次重要尝试,本文闸明计算机专用实时母系统在VAX/VMS环境下的工程实现。     

Water Crisis

Abstract

Water crisis was not considered seriously at the Dublin and Rio conferences. It was put on the world agenda primarily by the Stockholm Water Symposia. Water management is likely to change more during the next twenty years compared to the past 2,000 years. The paper reviews the global water situtation based on the latest data available. In terms of water availability, it concludes that one can now be cautiously optimistic of the global water future. If there is to be a crisis, it is likely to be for two reasons: water quality and lack of investments. Neither of these two issues are receiving adquate attention at present. The roles IWRA can play in the future are briefly outlined.     

直升机纵向系统鲁棒滑模控制律设计

在建立系统全包线T-S模糊模型的基础上,基于系统品质要求和可测状态约束条件,采用参数鲁棒设计方法,确定反馈控制参数的可用集合,实现等效控制律,相应确定系统的滑模面参数,给出了直升机纵向控制系统的全包线滑模控制律设计结果。仿真结果显示,系统具有较强的抗外界干扰能力,动态品质满足指标要求,表明文中提出的设计方法可行且有效。     

基于时域Neal-Smith准则的人机控制系统设计多目标优化研究

为了获得驾驶员和飞机良好的匹配特性,使用基于人机闭环参考模型的方法将飞行品质的要求引入优化算法,进行飞行控制系统设计。首先使用CAP准则建立飞机等效系统模型。然后,基于时域Neal-Smith准则,通过多目标优化算法一次性得到在不同任务条件下的最优驾驶员模型。根据需要选择相应的驾驶员模型,并与飞机等效系统模型组成人机闭环参考模型,进行飞行控制设计多目标优化。仿真结果显示,文中的算法不仅可以整定控制器参数,根据任务需求选取最优驾驶员模型,还可以利用优化结果进行PIO易感性的分析。     

Satisfying quality requirements in the design of a partition‐based,distributed stock trading system

Although quality requirements (QRs) have become a major drive in today's software development, there have been very few real‐world examples in the literature that demonstrate how to meet these requirements. This paper presents such an example. Specifically, the paper describes the design of a partition‐based distributed stock trading service system that satisfies a set of QRs related to resource utilization, performance, scalability and availability. The paper evaluates this design through detailed experiments and discusses some design alternatives and the lessons learned. Central to this design are a static load distribution strategy and a dynamic load balancing strategy. The first strategy is to achieve an initial balanced workload on the system's server cluster during the system initialization time, whereas the second strategy is to maintain this balanced workload throughout the system execution time. Together, these two strategies work in unison to ensure that the server resources are efficiently utilized; the user requests are processed with the required speed; the application is partitioned with sufficient room to scale; and the system is highly available. Copyright © 2011 John Wiley & Sons, Ltd.     

Effective user involvement in product development by improving the analysis of user needs

User involvement has been shown to be beneficial in the development of useful and usable systems. The trend of software development becoming a product-oriented activity creates challenges to user involvement. Field studies appear a promising approach, but the analysis of the gathered user needs has been shown to be demanding. This study presents, on the basis of seven case studies, an early user-involvement process showing how user needs can be analysed and how the input to product development can be identified. In addition, the process is evaluated in two industrial cases with interviews and a questionnaire. The results show that the process supports effective early user involvement; the resulted requirements were evaluated as being more successful and their quality as better than average in a company. However, the case studies show that user involvement not only provides useful information about users' needs but also increases the understanding of users' values.     

A trace metamodel proposal based on the model driven architecture framework for the traceability of user requirements in data warehouses

The complexity of the data warehouse (DW) development process requires to follow a methodological approach in order to be successful. A widely accepted approach for this development is the hybrid one, in which requirements and data sources must be accommodated to a new DW model. The main problem is that we lose the relationships between requirements, elements in the multidimensional (MD) conceptual models and data sources in the process, since no traceability is explicitly specified. Therefore, this hurts requirements validation capability and increases the complexity of Extraction, Transformation and Loading processes. In this paper, we propose a novel trace metamodel for DWs and focus on the relationships between requirements and MD conceptual models. We propose a set of Query/View/Transformation rules to include traceability in DWs in an automatic way, allowing us to obtain a MD conceptual model of the DW, as well as a trace model. Therefore, we are able to trace every requirement to the MD elements, further increasing user satisfaction. Finally, we show the implementation in our Lucentia BI tool.     

适应新形势的大城市停车需求预测方法

目前我国已探讨出多种停车需求预测方法,这些方法的前提条件和适用范围各有不同,并且我国大城市交通形势又出现了小汽车进入家庭速度加快,交通拥堵日益突出,轨道交通建设进入黄金时代等新的情况。针对这些新形式,提出了宏观和中观停车需求预测方法,宏观层次为考虑车辆出行吸引和车辆使用率的总体停车需求预测,弥补了以往未考虑未出行车辆停车需求的不足;中观层面为考虑公交可达性和多种性质建筑综合开发共享停车需求预测,可减少配建停车泊位,提高停车泊位利用率。进行实例分析,丰富和扩展了交通规划模型技术,为我国大城市开展停车交通研究提供参考。     

论唐寅《落花诗册》之反典而诗

唐寅在《落花诗册》中纵横使典,一气数典连用,而又不拘格俗,往往反典而用,以反典借古人景语言一己之情语,既不留行迹,又将自我多种复杂的心境展露无遗。同时,其化数家典故于一体,反典而不落陈套,手法不拘一格,表现了其极高的文学艺术修养。并且,其对于反典的偏爱,既是自我个性的张扬、不平的宣泄,也是对于"自性"的体悟和对"夺胎换骨"的继承,表现了其与禅宗之间甚深渊源。     

CWP／SU地震数据处理软件研究与应用

CWP／SU是美国科罗拉多矿业学院波场处理中心开发的一款免费的地球物理开源软件。其主要研究地震建模和成像,地震反演理论,以及复杂地质体地震数据处理算法,既可以作为地震数据处理环境,也可以作为波场处理的相关软件的研究与开发环境。其广泛应用于地震勘探开发领域,是一个很好的学习工具。本文主要是以SU地震处理软件为平台,进行了三个方面的研究与应用：基于SU的地震正演模拟;LIFT去噪方法在SU中的实现;基于SU的地震延时校正程序编写。