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81.
Gery M. van Veldhoven 《Journal of Economic Psychology》1985,6(1):1-8
Starting from literature a short sequential scheme is being presented, including contextual and causal factors of employment, phenomenal aspects of unemployment, moderator variables, effects and lastly interventions and solutions.General aspects as well as more restricted aspects of unemployment as an area of research within economic psychology are mentioned. The contributions within this issue are discussed in connection with the scheme and the different aspects that were distinguished. 相似文献
82.
针对差分跳频技术提出了一种G函数的非二进制卷积编码的等效模型,给出了差分跳频信号的最佳接收机设计方法,研究了维特比硬判决和维特比较判决两种最大似然检测算法,并对在AWGN信道下的两种最大似然检测算法的性能进行了计算机仿真。仿真结果表明,接收机采用最大似然检测算法对于改善系统的性能有明显的作用,对维特比硬判决法的实现方法进行了描述。 相似文献
83.
陈伟妮 《辽东学院学报(社会科学版)》2006,8(5):73-75
弗雷泽的《金枝》以内米湖畔的一个古老习俗展开,以世界各地的民间习俗为证,阐述了巫术与早期人类文化生活、宗教的关系。这个习俗是《金枝》赖以构建整个体系的基础,但它在祭司更替的问题上却出现了致命的漏洞,使弗雷泽据此得出的结论并不令人信服。 相似文献
84.
Martin S. Ridout Malcolm J. Faddy Michael G. Solomon 《Journal of the Royal Statistical Society. Series C, Applied statistics》2006,55(1):63-75
Summary. Many pesticide sprays that are used for crop protection are harmful to honey-bees. It can therefore be beneficial to add to the spray chemical compounds that are repellent to bees, to discourage them from feeding on recently sprayed crops. Experiments were conducted using an artificial feeding station to assess the repellent effects of various compounds. In this system, bees arrive at the feeding station, choose between feeding dishes to which different chemicals have been added, feed for a variable period and then depart. The number of bees at each feeding dish is recorded at intervals of 1 min. We discuss the analysis of data from this type of experiment, based on a queuing theory model. 相似文献
85.
王立勋 《中华女子学院学报》2004,16(6):64-67
随着电信业的发展,以3G为依托的一个巨大产业链已经开始形成,并将推动、促进新的电信市场格局的构建.面对这种形势,电信运营商应当采取有效的竞争策略,主动应对、打好品牌战略、挖掘用户潜在需求、建立有效的监管机制,从而为企业营造一个可持续发展的生态环境. 相似文献
86.
Y.P. Mack 《Journal of statistical planning and inference》1983,8(2):185-192
Let fn(x) be the univariate k-nearest neighbor (k-NN) density estimate proposed by Loftsgaarden and Quesenberry (1965). By using similar techniques as in Bahadur's representation of sample quantiles (1966), and by the recent results on the oscillation of empirical processes by Stute (1982), we derive the rate of strong uniform convergence of fn(x) on some suitably chosen interval Jδ. Some comparison with the kernel estimates is given, as well as the choice of the bandwidth sequence relative to the sample size. 相似文献
87.
Recursive estimates of a probability density function (pdf) are known. This paper presents recursive estimates of a derivative of any desired order of a pdf. Let f be a pdf on the real line and p?0 be any desired integer. Based on a random sample of size n from f, estimators f(p)n of f(p), the pth order derivatives of f, are exhibited. These estimators are of the form , where δjp depends only on p and the jth observation in the sample, and hence can be computed recursively as the sample size increases. These estimators are shown to be asymptotically unbiased, mean square consistent and strongly consistent, both at a point and uniformly on the real line. For pointwise properties, the conditions on f(p) have been weakened with a little stronger assumption on the kernel function. 相似文献
88.
David G. Gil 《Children and youth services review》1984,6(4):299-309
This paper examines consequences for child development and well-being of the prevailing institutional order and ideology of the United States and concludes that child development in our country is severely obstructed because of socially structured violence which permeates our way of life. The paper ends with comments on prospects for social transformation which seems necessary to assure the development and well-being of every child. 相似文献
89.
For testing the hypothesis that several (s?2) linear regression surfaces Xki=αk+βkcki+Zki (k=1,…,s) are parallel to one another, i.e., β1=?=βs, a class of rank-order tests are considered. The tests are shown to be asymptotically distribution-free, and their asymptotic efficiency relative to the general likelihood ratio test is derived. Asymptotic optimality in the sense of Wald is also discussed. 相似文献
90.
We consider the problem of binary-image restoration. The image being restored is not random, and we make no assumption about the nature of its contents. The estimate of the colour at each site is a fixed (the same for all sites) function of the data available in a neighbourhood of that site. Under this restriction, the estimate minimizing the overall mean squared error of prediction is the conditional expectation of the true colour given the observations in the neighbourhood of a site. The computation of this conditional expectation leads to the formal definition of the local characteristics of an image, namely, the frequency with which each pattern appears in the true unobserved image. When the “true” distribution of the patterns is unknown, it can be estimated from the records. The conditional expectation described above can then be evaluated using the estimated distribution of the patterns, and this procedure leads to a very natural estimate of the colour at each site. We propose two unbiased and consistent estimates for the distribution of patterns when the noise is a Gaussian white noise. Since the size of realistic images is very large, the estimated pattern distribution is usually close to the true one. This suggests that the estimated conditional expectation can be expected to be nearly optimal. An interesting feature of the proposed restoration methods is that they do not require prior knowledge of the local or global properties of the true underlying image. Several examples based on synthetic images show that the new methods perform fairly well for a variety of images with different degrees of colour continuity or textures. 相似文献