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11.
介绍了未来高速移动通信新标准IEEE802.20的总体概况,具体分析了IEEE802.20的技术特性、系统参考结构以及系统的组成模型,并对IEEE802.20标准前景分析与展望进行了详细描述。  相似文献   
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Thinking about future needs and about what can reasonably be expected as feasible in the next century, how should producers of statistics direct their activity? Increasing complexity and diversity of needs leads us to recognize that, between producers and users of statistics, a mediating role is more and more often played by analysts and research workers who are requesting above all good data bases. Concerning infrastructures for statistics on productive systems, coordination between accountants and statisticians will be crucial, as well as adaptation of the constraints which, because of excessive worry about confidentiality, could prevent establishment or use of data bases. In an increasingly competitive world, where private firms will sell analyses and informations, particularly on very large enterprises, the public statistical service will remain essential in all respects. Intangible investments, innovations and many aspects of the internal organization of firms will create formidable challenges. Information on employment and labour markets has been much developed during the past decades; but on a few specific and difficult issues progress is still needed: lifecyles in the working-age population, acquisition of knowledge and skills in formal education and on the job, matching labour supplies and demands, and so on. Particular attention will have to be given to the lower levels of cultural and professional skills.  相似文献   
14.
以油藏监测工作中的油藏压力监测为例,介绍了标准化工作在压力资料录取及解释分析中的作用。并用实例说明了标准化作业在油田开发方案的制定及油藏压力监测中的应用。  相似文献   
15.
The Nested PIGLOG Model: An Application to U.S. Food Demand   总被引:1,自引:0,他引:1  
A new demand system is introduced, the Nested PIGLOG model, nesting thirteen other demand systems including five that are also new. This new model and its nested special cases are applied to models of U.S. food demand that include food-at-home (FAH), food-away-from-home (FAFH), and alcoholic beverages. Although nested tests and out-of-sample forecasting performance favor generalizing models to a certain degree, statistically insignificant improvements to in-sample-fit and even poorer out-of-sample forecast accuracy undermine further generalizations. Based on a subset of preferred models, FAFH is found to be price and income elastic compared to FAH which is price and income inelastic.  相似文献   
16.
We evaluate and qualify Friedman's, 1953, “case for flexible exchange rates” in the presence of sticky prices in a two country model. We find that a flexible regime performs indeed better when the degree of nominal price rigidity is high while a bilateral peg does better when prices are fairly flexible. This result obtains independent of whether monetary policy is activistic or not and is mostly due to the negative relationship between employment and productivity shocks when prices are relatively sluggish (Gali, 1999). A unilateral peg tends to produce the lowest level of world welfare but it sometimes represents the best monetary arrangement for the pegger. JEL Classification Numbers: E32, E52, F33, F42  相似文献   
17.
Operational Research and the environment   总被引:1,自引:1,他引:0  
The discipline of Operational Research (OR) is primarily concerned with improving the effectiveness and efficiency of decision processes. These processes take place everywhere in society: industry, banking, agriculture, government, politics. Frequent use of mathematical optimization models is typical of OR. Since the early '80s these models are increasingly packaged in a user-friendly way, as Decision Support Systems. In the following we will illustrate how OR can be used to describe and solve a number of environmental problems.  相似文献   
18.
虞汉华  虞谦 《物流技术》2005,(10):344-347
根据南京市重大危险源普查报告,分析了南京市重大危险源的基本状况和监管中存在的问题,以提高应急物流反应能力为目标,分别从监管模式的改进、监管政策保障措施建设和重大危险源监管体系建设等三个方面提出了提高南京市重大危险源监管水平的对策措施。  相似文献   
19.
为了了解黄石市空气微生物动态变化特征,于2004年春、夏、秋、冬选择黄石市有代表性的工业区、居民区、商业交通混合区、长途客运站、市郊地区进行空气微生物监测分析.结果为黄石市不同区域空气菌落数从大到小顺序为:百货大楼十字路口〉步行街〉亚光新村〉新长途客运站〉华新水泥厂〉黄石理工学院主楼广场.空气微生物季节变化为秋季〉春季〉夏季〉冬季.黄石市空气微生物菌落数的高峰出现在商业交通混合区的秋季和春季.  相似文献   
20.
以《循环经济法草案征求意见稿》第17条规定的以生产者为主的责任延伸制度为基点,分析了以生产者为主的责任延伸制度的内涵、弊端及其实施的保障机制,指出以生产者为主的生产责任延伸制度的主体应包含政府,责任形式应增加行政责任和刑事责任,并对保障机制加以分类,具体阐述了生命周期评价制度、认证单制度、产品回收制度、监督制度、抵押制度等。  相似文献   
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