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41.
研究了一种新型的可靠性系统,即间歇开放系统。在建立数学模型的基础上,我们详细分析了系统有关的可靠性问题,不仅获得时刻t系统失效的概率和(0,t]中系统失效的平均次数的瞬态解,而且也获得其平稳结果。最后用数值计算比较了间歇开放系统和经典系统的差别。  相似文献   
42.
对合作处理中的一些基本概念给出了明确的定义,并提出了一个有用的合作团队的模型。模型中的团队代理是实现透明性的依托,在此对其特性、行为及其构造作了描述。把合作团队的透明性分解为环境透明和编程透明,并给出两种进明性在OSEware中的实现方法。  相似文献   
43.
Journal of Combinatorial Optimization - In medical outpatient services, due to patients’ imbalanced selection for doctors of different levels and for different visiting periods, inefficiency...  相似文献   
44.
This paper examines the mediating mechanism of the relationship between institutional voids (IVs) and inter‐firm cooperation and the moderating role of economic adversity in the context of small and medium‐sized enterprises (SMEs) based in emerging markets. The hypotheses are tested using time‐lagged survey data from 214 SMEs in Ghana. The findings provide support for the hypotheses by showing that: (1) IVs positively influence the use of government research and development (R&D) support; (2) the use of government R&D support mediates the relationship between IVs and inter‐firm cooperation; and (3) economic adversity positively moderates the relationship between IVs and the use of government R&D support. The findings contribute to understanding the role of IVs in inter‐firm cooperation. The wider implications for theory and practice are examined.  相似文献   
45.
荞麦中苯丙氨酸解氨酶活力与黄酮含量的关系   总被引:1,自引:0,他引:1  
荞麦幼苗及幼苗不同器官中黄酮含量随着苯丙氨酸解氨酶(PAL)活力变化而变化。X射线处理可增强荞麦幼苗中苯丙烷类代谢途径,致使黄酮含量提高。由此推测,苯丙氨酸解氨酶活力与黄酮类次生物质的形成具有密切关系。  相似文献   
46.
给出二维变系数线性微分系统在已知某解的情形下求通解的公式,并直接应用此公式,导出几类二维变系数线性微分系统的通解公式.对理论和实际应用都是有益的.  相似文献   
47.
预测“九五”至2010年中国地区经济发展,分析区域经济发展的两大特征,总结影响地区经济发展差别的基本规律,提出促进中国区域经济协调发展的政策选择。  相似文献   
48.
Risk Modeling, Assessment, and Management of Lahar Flow Threat   总被引:1,自引:0,他引:1  
The 1991 eruption of Mount Pinatubo in the Philippines is considered one of the most violent and destructive volcanic activities in the 20th century. Lahar is the Indonesian term for volcanic ash, and lahar flows resulting from the massive amount of volcanic materials deposited on the mountain's slope posed continued post-eruption threats to the surrounding areas, destroying lives, homes, agricultural products, and infrastructures. Risks of lahar flows were identified immediately after the eruption, with scientific data provided by the Philippine Institute of Volcanology, the U.S. Geological Survey, and other research institutions. However, competing political, economic, and social agendas subordinated the importance of scientific information to policy making. Using systemic risk analysis and management, this article addresses the issues of multiple objectives and the effective integration of scientific techniques into the decision-making process. It provides a modeling framework for identifying, prioritizing, and evaluating policies for managing risk. The major considerations are: (1) applying a holistic approach to risk analysis through hierarchical holographic modeling, (2) applying statistical methods to gain insight into the problem of uncertainty in risk assessment, (3) using multiobjective trade-off analysis to address the issue of multiple decisionmakers and stakeholders in the decision-making process, (4) using the conditional expected value of extreme events to complement and supplement the expected value in quantifying risk, and (5) assessing the impacts of multistage decisions. Numerical examples based on ex post data are formulated to illustrate applications to various problems. The resulting framework from this study can serve as a general baseline model for assessing and managing risks of natural disasters, which the Philippines' lead agency-the National Disaster Coordinating Council (NDCC)-and other related organizations can use for their decision-making processes.  相似文献   
49.
This paper reports the findings from a recent study of nurse leavers at eight large hospitals in the National Health Service (NHS) of England and Wales. The study develops and extends an influential theory of employee turnover by describing how for some leavers a single, jarring event or shock triggers the decision to quit. By elaborating on the nature of shocks for this sample of 352 nurse leavers, the paper allows for improved understanding of nursing turnover and thus offers an example of relevant management research. The analysis of shock illustrates how conventional research methodologies can lead to a distorted picture of turnover. This has wider implications, both for any organization wishing to manage turnover effectively and for future research. The paper adds to the limited body of empirical analysis on actual leavers, thereby contributing to an ongoing methodological debate concerning the use of proxy variables. By highlighting flaws in the dominant methodology used to study turnover, the paper offers an example of management research that is also rigorous, and thus ‘pragmatic’.  相似文献   
50.
高分辨定位技术在近几年得到人们的广泛注意,在这方面的研究工作相当活跃。本文提出一种新的多目标阵列接收信号协方差矩阵的去噪方法,并对结果进行了计算机模拟。  相似文献   
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