4 resultados para Evaluation research (Social action programs)

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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The Southeast Asia and Western Pacific regions contain half of the world's children and are among the most rapidly industrializing regions of the globe. Environmental threats to children's health are widespread and are multiplying as nations in the area undergo industrial development and pass through the epidemiologic transition. These environmental hazards range from traditional threats such as bacterial contamination of drinking water and wood smoke in poorly ventilated dwellings to more recently introduced chemical threats such as asbestos construction materials; arsenic in groundwater; methyl isocyanate in Bhopal, India; untreated manufacturing wastes released to landfills; chlorinated hydrocarbon and organophosphorous pesticides; and atmospheric lead emissions from the combustion of leaded gasoline. To address these problems, pediatricians, environmental health scientists, and public health workers throughout Southeast Asia and the Western Pacific have begun to build local and national research and prevention programs in children's environmental health. Successes have been achieved as a result of these efforts: A cost-effective system for producing safe drinking water at the village level has been devised in India; many nations have launched aggressive antismoking campaigns; and Thailand, the Philippines, India, and Pakistan have all begun to reduce their use of lead in gasoline, with resultant declines in children's blood lead levels. The International Conference on Environmental Threats to the Health of Children, held in Bangkok, Thailand, in March 2002, brought together more than 300 representatives from 35 countries and organizations to increase awareness on environmental health hazards affecting children in these regions and throughout the world. The conference, a direct result of the Environmental Threats to the Health of Children meeting held in Manila in April 2000, provided participants with the latest scientific data on children's vulnerability to environmental hazards and models for future policy and public health discussions on ways to improve children's health. The Bangkok Statement, a pledge resulting from the conference proceedings, is an important first step in creating a global alliance committed to developing active and innovative national and international networks to promote and protect children's environmental health.

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作为信息存储和处理的核心环节,数据库管理系统的安全性在整个信息安全体系结构中起着至关重要的作用。高安全等级数据库管理系统的设计与测评既是当前发展的客观需求,同时也是一个极大的挑战。针对这一挑战,本文以高安全等级数据库系统及其测评关键技术为中心展开了一系列工作,并取得了以下重要成果: (1)针对高安全等级数据库系统安全功能开发过程中的问题,本文提出基于通用标准的数据库安全功能开发方法,采用自顶而下的安全需求定义方法,依次对系统运行环境分析、安全目标定义直到可用性表示等开发中的问题进行了分析。依此方法开发的安全产品可以完备地应对安全环境中的所有威胁。 (2)提出了入侵容忍的数据库恶意事务处理方法。该方法利用在事务管理器层次扩展的事务恢复日志分析和查找恶意事务的后继,通过数据回滚使受损数据在线的恢复至攻击前的状态。本文证明了该方法的完备性和正确性,与现有技术相比,该方法可以获得更高的运行效率。 (3)针对信息安全产品测评无法量化的问题,本文提出了一种基于三角模糊数的安全保证量化评估方法。量化评估方法包括:如何构造保证评估框架;如何使用模糊数标识评估员对组件的评价和对权重的分配;如何使用底线折中法形成量化的安全评价值。应用该方法进行测评,可使产品安全性以指标值的形式呈现,方便采购方和决策者规避安全风险。 (4)提出了高等级数据库系统测评平台的实现方法。给出兼容GB17859和GB18336等不同标准体系、高度集成、扩展性良好,并具有保护轮廓评估、安全目标评估、测试用例生成、测试案例管理、安全保证评估和模型形式化验证等功能的测评平台实现方法。为测评人员进行高安全等级数据库产品的测试和评估提供了一个全面的操作平台,提高了测评工作的自动化程度。 总的来说,本文的研究成果推动了高安全等级数据库管理系统及其测评关键技术研究的发展,并为实现我国高等级数据库管理系统及其测评打下了坚实的基础。

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本文以863-512型号项目为背景,从运动特性、运动描述、运动控制以及运动规划等几个方面研究履带式移动机器人的行动规划技术;首先从理论上分析了履带式移动机器人的内在运动传递机理,指出了其区别于轮式移动载体的独特的运动特性,尤其是在其转向特性方面,得出了履带式移动机器人运动角速度几乎不可控原理、原地转弯转不准问题、以及履带式车辆行动规划时所要遵循的规则等重要结论,针对履带式移动机器人的纵向运动控制问题,讨论了其速度控制模型,提出了一种速度测量与控制的简单、准确、可靠的方法。在磺向运动方面,提出了一种基于FM-LIKE和AM-LIKE相结合的复合控制技术,解决了难度较大的方向控制问题。最后提供了实验结果,证明了上述方法与结论的正确性。上述方法与结论,作为863-512某型号任务的一部分,业已通过验收。

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Since physical properties and resistivity of mixed formation fluid change after polymer and water flood reservoir, transformational electric properties of water and polymer flooded zones challenges log interpretation. Conventional log interpretation methods to water flooded reservoirs cannot be employed to water and polymer flooded zones. According to difficulties in water and polymer flooded zones interpretation, we analyzed the variation of electric properties of mixed formation fluid, reservoir parameters and log correspondences, then got further understanding of the applicability of Archie Equations. As the results, we provided reservoir parameter evaluation model in water and polymer flooded zones in this paper. This research shows that micro pore structure, physical parameters and electric correspondence of reservoirs change after being flooded by water and polymer. The resistivity variation of mixed formation fluid depends mainly on affixation conductivity of polymer and salinity of formation water, which is the key to log interpretation and evaluation. Therefore, we summerized the laws of log correspondence in different polymer injection ways, developed electric discrimination model for water and polymer flooded zones, as well as charts to identify flooding conditions with resistivity and sonic logs. Further rock-electric tests and conductive mechanism analysis indicate that the resistivity increasing coefficient(I) and water saturation(Sw) are still in concordance with classical Archie Equations, which can be utilized in quantitative evaluation on water and polymer flooded reservoirs. This sets of methods greatly improved accuracy in water and polymer flooded zone evaluation.