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51.
Summary.  To investigate the variability in energy output from a network of photovoltaic cells, solar radiation was recorded at 10 sites every 10 min in the Pentland Hills to the south of Edinburgh. We identify spatiotemporal auto-regressive moving average models as the most appropriate to address this problem. Although previously considered computationally prohibitive to work with, we show that by approximating using toroidal space and fitting by matching auto-correlations, calculations can be substantially reduced. We find that a first-order spatiotemporal auto-regressive (STAR(1)) process with a first-order neighbourhood structure and a Matern noise process provide an adequate fit to the data, and we demonstrate its use in simulating realizations of energy output.  相似文献   
52.
The ability to infer parameters of gene regulatory networks is emerging as a key problem in systems biology. The biochemical data are intrinsically stochastic and tend to be observed by means of discrete-time sampling systems, which are often limited in their completeness. In this paper we explore how to make Bayesian inference for the kinetic rate constants of regulatory networks, using the stochastic kinetic Lotka-Volterra system as a model. This simple model describes behaviour typical of many biochemical networks which exhibit auto-regulatory behaviour. Various MCMC algorithms are described and their performance evaluated in several data-poor scenarios. An algorithm based on an approximating process is shown to be particularly efficient.  相似文献   
53.
以旅游业为龙头推进西部地区城镇化建设   总被引:1,自引:0,他引:1  
城镇化是人类社会发展和进步的必然趋势 ,是衡量一定地域经济社会发展水平和文明程度的重要标志。针对我国西部地区以农村人口为主和城镇与农村并存的特点 ,西部要发展就必须找准突破口 ,加强地方经济建设 ,推进城镇化进程  相似文献   
54.
The authors provide an overview of optimal scaling results for the Metropolis algorithm with Gaussian proposal distribution. They address in more depth the case of high‐dimensional target distributions formed of independent, but not identically distributed components. They attempt to give an intuitive explanation as to why the well‐known optimal acceptance rate of 0.234 is not always suitable. They show how to find the asymptotically optimal acceptance rate when needed, and they explain why it is sometimes necessary to turn to inhomogeneous proposal distributions. Their results are illustrated with a simple example.  相似文献   
55.
讨论了铁磁性金属薄膜中的各向弄性磁阻效应。通过对晶体结构分析和实验验证,提出了一种假设:在外磁场作用下,产生了原子对的方向有序化,导致感生磁各向异性,并使晶体织构消失。根据对5种样品的实测数据,讨论了薄膜的动态磁化过程。  相似文献   
56.
公路建设项目施工期全程环境管理   总被引:9,自引:2,他引:7  
通过分析公路施工期公路施工对自然生态、大气、声、水环境以及社会环境的影响,针对公路施工期环境管理的薄弱状态及施工期环境监理尚处于试点研究阶段的现状,提出了公路建设项目施工期全程环境管理的理念,建立施工期全程环境管理制度的思想:承包商、监理、业主及政府环保部门共同承担环保责任的“四位一体”的施工期环境管理模式,并对其内涵进行了分析。这对建立公路建设项目施工期全程环境管理制度、规范施工期的环境管理有着积极的推动作用。  相似文献   
57.
Summary. Standard goodness-of-fit tests for a parametric regression model against a series of nonparametric alternatives are based on residuals arising from a fitted model. When a parametric regression model is compared with a nonparametric model, goodness-of-fit testing can be naturally approached by evaluating the likelihood of the parametric model within a nonparametric framework. We employ the empirical likelihood for an α -mixing process to formulate a test statistic that measures the goodness of fit of a parametric regression model. The technique is based on a comparison with kernel smoothing estimators. The empirical likelihood formulation of the test has two attractive features. One is its automatic consideration of the variation that is associated with the nonparametric fit due to empirical likelihood's ability to Studentize internally. The other is that the asymptotic distribution of the test statistic is free of unknown parameters, avoiding plug-in estimation. We apply the test to a discretized diffusion model which has recently been considered in financial market analysis.  相似文献   
58.
The authors consider the issue of map positional error, or the difference between location as represented in a spatial database (i.e., a map) and the corresponding unobservable true location. They propose a fully model‐based approach that incorporates aspects of the map registration process commonly performed by users of geographic informations systems, including rubber‐sheeting. They explain how estimates of positional error can be obtained, hence estimates of true location. They show that with multiple maps of varying accuracy along with ground truthing data, suitable model averaging offers a strategy for using all of the maps to learn about true location.  相似文献   
59.
本文研究了等效法在中学物理教学中的应用,并结合一些具体实例进行了分析,对中学物理教学有一定指导意义。  相似文献   
60.
随着市场经济的完善和发展,面对激烈的竞争,为了稳定销售渠道、扩大产品销路、减少存货.企业间相互提供商业信用的情况与日俱增。主要探讨了企业如何对应收账款实行事前、事中和事后的全过程控制,制定合理的信用政策来加强应收账款的管理,加速应收账款回笼,减少坏账,确保企业经营利润的最终实现。  相似文献   
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