Discrete Multicolour Random Mosaics with an Application to Network Extraction

We introduce a class of random fields that can be understood as discrete versions of multicolour polygonal fields built on regular linear tessellations. We focus first on a subclass of consistent polygonal fields, for which we show Markovianity and solvability by means of a dynamic representation. This representation is used to design new sampling techniques for Gibbsian modifications of such fields, a class which covers lattice‐based random fields. A flux‐based modification is applied to the extraction of the field tracks network from a Synthetic Aperture Radar image of a rural area.     

A network algorithm for the exact treatment of the 2×k contingency table

A common statistical problem encountered in biomedical research is to test the hypothesis that the parameters of k binomial populations are all equal. An exact test of significance of this hypothesis is possible in principle, the appropriate null distribution being a normalized product of k binomial coefficients. However, the problem of computing the tail area of this distribution can be formidable since it requires the enumeration of all sets of k binomial coefficients whose product is less than a given constant. Existing algorithms, all of which rely on explicit enumeration to generate feasible binomial coefficients     

Extreme probabilities for contingency tables under row and column independence with application to fisher's exact test

Theorerms are proved for the maxima and minima of IIR_i!/IIC_j!/T!II_yij ! over r× c contingcncy tables Y=(y_ij) with row sums R₁,…,R_r, column sums C₁,…,C_c, and grand total T. These results are imlplemented into the network algorithm of Mehta and Patel (1983) for computing the P-value of Fisher's exact test for unordered r×c contingency tables. The decrease in the amount of computing time can be substantial when the column sums are very different.     

中国城市化与生态环境协调发展预警系统研究

本文构建了城市化与生态环境协调发展预警指标体系,并对1991～2010年中国城市化与生态环境的协调度进行了测算及预测,根据协调度建立了预警系统,并对90年代以来中国城市化与生态环境的协调发展进行了分析。结果表明,2007年以来,中国的生态环境不断恶化,城市化与生态环境的协调度不断下降,保护生态环境成为城市化进程中的重要问题。     

Designing and integrating composite networks for monitoring multivariate gaussian pollution fields

Networks of ambient monitoring stations are used to monitor environmental pollution fields such as those for acid rain and air pollution. Such stations provide regular measurements of pollutant concentrations. The networks are established for a variety of purposes at various times so often several stations measuring different subsets of pollutant concentrations can be found in compact geographical regions. The problem of statistically combining these disparate information sources into a single 'network' then arises. Capitalizing on the efficiencies so achieved can then lead to the secondary problem of extending this network. The subject of this paper is a set of 31 air pollution monitoring stations in southern Ontario. Each of these regularly measures a particular subset of ionic sulphate, sulphite, nitrite and ozone. However, this subset varies from station to station. For example only two stations measure all four. Some measure just one. We describe a Bayesian framework for integrating the measurements of these stations to yield a spatial predictive distribution for unmonitored sites and unmeasured concentrations at existing stations. Furthermore we show how this network can be extended by using an entropy maximization criterion. The methods assume that the multivariate response field being measured has a joint Gaussian distribution conditional on its mean and covariance function. A conjugate prior is used for these parameters, some of its hyperparameters being fitted empirically.     

基于最大收益的无线虚拟网络重映射算法

针对无线环境的动态性及虚拟网络请求到达与离开的随机性,使得物理网络负载分布不均衡,导致后续请求的接受率降低的问题,提出一种无线网络虚拟化中的两阶段重映射算法（two stages reconfiguration scheme for wireless network virtualization,TR-WNV）。该算法通过第1个阶段选出合适的虚拟网络进行重映射,接着在第2个阶段按照优先级对已选出的虚拟网络进行重映射,并根据离散度来判断每次映射效果。最后,通过仿真对算法进行验证,结果表明该算法在保证虚拟网络请求收益最大化同时,有效提高了虚拟网络请求接受率,实现整个底层网络的负载分布均衡。     

我国电子商务当前存在的问题及发展策略

当前我国电子商务发展总体状况良好,但尚存在不少问题,如电子商务安全性问题、电子商务的法规健全问题、电子商务的税收问题等等。这些问题大大影响了我国电子商务的健康发展,因此必须引起各方重视,迅速采取一些有效的举措以加速我国电子商务的发展。     

多焊接电源控制技术

现代的膜式水冷壁制造工艺要求多达２０台焊接电源同时工作,当外网原因使车间供电电压波动的时候,焊接电源群同时进行调整。群焊接电源的冲击性载荷对电网进行反激,导致电网的更大波动。文章引入优先级的概念,将自适应神经模糊推理系统(ANFIS)应用到焊接电源群的优先级控制上,设计了自适应神经模糊推理网络,并利用MATLAB平台进行整个焊接系统的建模和仿真。结果表明应用该优先级群控策略,各焊机调整能力加强,调整时间缩短,动态性能得到改善。     

中国乡村研究范式述评

对中国乡村研究的范式进行了梳理,从各大理论的建构及对经济、社会、文化、政治的影响分析了最为典型的5种范式,即费孝通的社区功能研究方法、施坚雅的市场关系研究方法、杜赞奇的文化网络研究方法、弗里德曼的宗族系统研究方法以及黄宗智的市场一阶级研究方法,对其特征和缺陷进行了适当的梳理。分析认为,中国乡村研究应以农户行为为中心,多学科、多领域的研究,任何试图将其纳入某一种框架的理论是不能成功的。     

社群共同体之“公共善”何以具有优先性——“实用主义”政治伦理信念的正当性辨析

在有关社群共同体生活的政治伦理信念和道德价值之维的根据与合理性问题上,实用生义哲学基于公共善本位的“有效性思维”理论,用所谓“统一的经验整体”的理论,厘清了“社会”与社群“共同体”的合理关系问题.在政治伦理的价值信念问题上,实用主义致力于个体利益与社会利益的实践整合,将社会正义视为社群共同体的最高德性,以此实现对民主共同体之生活模式的构筑以及“民主化了的个人形象”的实践塑造.实用主义有关正确划定“政治国家”和社群共同体边界的思想,对身处现代性进程中的中国社会克服狭隘经验主义与功利主义等的社会伦理观,具有重要的启发与借鉴意义.