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991.
西安新农村建设规划的地域特色研究 总被引:1,自引:0,他引:1
模糊的建设目标,非根植性的规划模式,急功近利的建设速度等致使西安新农村建设羁绊丛丛。针对西安新农村建设所存在的问题,结合西安新农村建设的现实基础,明确提出了西安新农村建设的目标体系,归纳总结了近年来西安新农村建设的适宜模式,并初步提出了提高西安新农村建设规划综合效益的改进策略,以期高效推进西安新农村建设的有序开展。 相似文献
992.
This paper is concerned with the estimation of a general class of nonlinear panel data models in which the conditional distribution of the dependent variable and the distribution of the heterogeneity factors are arbitrary. In general, exact analytical results for this problem do not exist. Here, Laplace and small-sigma appriximations for the marginal likelihood are presented. The computation of the MLE from both approximations is straightforward. It is shown that the accuracy of the Laplace approximation depends on both the sample size and the variance of the individual effects, whereas the accuracy of the small-sigma approximation is 0(1) with respect to the sample size. The results are applied to count, duration and probit panel data models. The accuracy of the approximations is evaluated through a Monte Carlo simulation experiment. The approximations are also applied in an analysis of youth unemployment in Australia. 相似文献
993.
M.V. Ramakrishna 《统计学通讯:理论与方法》2013,42(11):3343-3353
We analyze the probability of a random distribution of n balls into m urns of size b resulting in no overflows. This solves the computational problem associated with a classical combinatorial extreme-value distribution. The problem arose during the analysis of a technique, called perfect hashing, for organizing data in computer files. The results and techniques presented can be used to solve several problems in the analysis of hashing techniques 相似文献
994.
通过抽样考察,可窥见我国理工高校法律人才培养模式总体现状欠佳,其主要存在这样几个问题:一是培养模式未彰显特色,培养目标指向趋于同质,定位模糊;二是培养机制缺乏制度化支撑,长久动力不足,人才培养缺乏竞争优势。理工高校应以应用复合型卓越法律人才培养目标的确立,特定法律人才培养机制的建构,特色法律专业课程的设计和教学方法的创新,以及法律人才培养模式的制度化保障等四个方面为进路,尽快改变理工高校法律人才培养的欠佳状况。 相似文献
995.
Denys Yemshanov Frank H. Koch Daniel W. McKenney Marla C. Downing Frank Sapio 《Risk analysis》2009,29(6):868-884
Nonindigenous species have caused significant impacts to North American forests despite past and present international phytosanitary efforts. Though broadly acknowledged, the risks of pest invasions are difficult to quantify as they involve interactions between many factors that operate across a range of spatial and temporal scales: the transmission of invading organisms via various pathways, their spread and establishment in new environments. Our study presents a stochastic simulation approach to quantify these risks and associated uncertainties through time in a unified fashion. We outline this approach with an example of a forest pest recently detected in North America, Sirex noctilio Fabricius. We simulate new potential entries of S. noctilio as a stochastic process, based on recent volumes of marine shipments of commodities from countries where S. noctilio is established, as well as the broad dynamics of foreign marine imports. The results are then linked with a spatial model that simulates the spread of S. noctilio within the geographical distribution of its hosts (pines) while incorporating existing knowledge about its behavior in North American landscapes. Through replications, this approach yields a spatial representation of S. noctilio risks and uncertainties in a single integrated product. The approach should also be appealing to decisionmakers, since it accounts for projected flows of commodities that may serve as conduits for pest entry. Our 30-year forecasts indicate high establishment probability in Ontario, Quebec, and the northeastern United States, but further southward expansion of S. noctilio is uncertain, ultimately depending on the impact of recent international treatment standards for wood packing materials. 相似文献
996.
《统计学通讯:理论与方法》2013,42(7):1353-1372
The paper derives Bartlett corrections for improving the chisquare approximation to the likelihood ratio statistics in a class of location-scale family of distributions, which encompasses the elliptical family of distributions and also asymmetric distributions such as the extreme value distributions. We present, in matrix notation, a Bartlett corrected likelihood ratio statistic for testing that a subset of the nonlinear regression coefficients in this class of models equals a given vector of constants. The formulae derived are simple enough to be used analytically to obtain several Bartlett corrections in a variety of important models. We show that these formulae generalize a number of previously published results. We also present simulation results comparing the sizes and powers of the usual likelihood ratio tests and their Bartlett corrected versions when the scale parameter is considered known and when this parameter is uncorrectly specified. 相似文献
997.
传统的教学由于受时间和空间的限制,越来越满足不了现代社会的终身学习需要,网络教育、远程教育因其具有远距离、实时、交互性强、多媒体化、随时随地学习的特点已成为现代教育最重要的组成部分。 相似文献
998.
《Journal of social work practice in the addictions》2013,13(2):93-105
Abstract Efforts on the part of the sci en tific com mu nity have resulted in in creased knowl edge about to bacco ad die tion and im proved treat ment ef fi cacy. De spite these gains, how ever, our un der stand ing of to bacco ad die tion re mains in com plete. Two el e ments that may help il lu-mi nate the knowl edge of this ad die tion pro cess and pro vide im pli ca tions for treat ment are the Transtheoretical Model of Change and the con cept of ex pec tan cies. This project is a be gin ning step in ex plor ing the re la tion ship be tween the transtheoretical model and fac ets of ex pec tan cies among col lege smokers. 相似文献
999.
陈红照 《四川理工学院学报(社会科学版)》2009,24(1):21-23
三十年改革开放实践进程与中国特色社会主义理论体系相辅相承,实践和理论相互提升,不断发展。改革开放实践推动着中国特色社会主义理论体系不断发展、完善,中国特色社会主义理论体系的形成、发展和不断创新,为我国改革开放的进行提供了有力的科学指导和理论支撑,推动了我国改革开放实践进程的不断深入发展。只有坚持不懈地推进改革开放,才能发展和完善中国特色社会主义理论体系,同时,也只有坚持好发展好中国特色社会主义理论体系.才能更好地推进改革开放的进一步发展。 相似文献
1000.
Stochastic scenario trees are a new and popular method by which surveillance systems can be analyzed to demonstrate freedom from pests and disease. For multiple component systems—such as a combination of a serological survey and systematically collected observations—it can be difficult to represent the complete system in a tree because many branches are required to represent complex conditional relationships. Here we show that many of the branches of some scenario trees have identical outcomes and are therefore redundant. We demonstrate how to prune branches and derive compact representations of scenario trees using matrix algebra and Bayesian belief networks. The Bayesian network representation is particularly useful for calculation and exposition. It therefore provides a firm basis for arguing disease freedom in international forums. 相似文献