电子商务立法的国际比较及对我国的启示

电子商务的迅速发展实质性地改变了传统市场交易的形式。而作为法律调整和规范的主要对象之一，交易形式的变化要求有新的法律规定与之相适应。在国际上，关于电子商务的立法活动已经形成了一种浪潮。而我国的电子商务立法工作却一直进展缓慢。其中有认识上的问题，更主要的是立法经验的不足。借鉴有关国家电子商务立法的先进经验，我国应当尽快建立和完善电子商务法制，这其中包括应当建立关于电子签名、电子商务认证、电子合同、电子支付等方面的法律规则与制度。     

从环境和建筑看生态建筑设计

建筑师和生态学家对环境和建筑的认识存在着一定的差异。生态建筑设计需要建筑师借鉴生态学家的认识 ,建立一种整体的建筑观念。依托整体生态观和系统观念建立起来的整体生态建筑观包括两个方面的内容 :其一是建筑系统在全寿命过程中 ,持续地与周围生态系统环境相互作用 ;其二是建筑系统对周围生态系统会产生空间置换影响 ,而这种影响具有一定的空间范围     

A non-profit approach to addressing the effects of urbanization in the Lake Pontchartrain Basin, Louisiana

The Lake Pontchartrain Basin in southeast Louisiana is an estuarine watershed encompassing New Orleans, Baton Rouge, and wetlands that are an integral part of Louisiana's unique culture. In recent decades rapid growth and poorly planned development have resulted in a decrease in water quality and habitat loss, especially in St. Tammany Parish on the north shore of Lake Pontchartrain. In 1989, the Lake Pontchartrain Basin Foundation (LPBF), an environmental, non-profit organization, was formed to address and rectify environmental issues in the Basin. LPBF accomplishes its mission through programs addressing water quality, habitat protection, geographic information science, public access, and education.LPBF used the recent, rapid development occurring in St. Tammany Parish as a case study to examine the relationship between land use, water quality, and development in the Basin by investigating habitat change/urbanization, development in flood plains, and water quality. Through the integration of LPBF programs, it was found that urbanization is having a devastating impact on the parish's natural habitats and severely degrading water quality. Using these results, LPBF is educating Basin citizens on the protection of their habitats and water quality to insure that these resources may be available for future generations.     

An affine‐invariant multivariate sign test for cluster correlated data

The author presents a multivariate location model for cluster correlated observations. He proposes an affine‐invariant multivariate sign statistic for testing the value of the location parameter. His statistic is an adaptation of that proposed by Randles (2000). The author shows, under very mild conditions, that his test statistic is asymptotically distributed as a chi‐squared random variable under the null hypothesis. In particular, the test can be used for skewed populations. In the context of a general multivariate normal model, the author obtains values of his test's Pitman asymptotic efficiency relative to another test based on the overall average. He shows that there is an improvement in the relative performance of the new test as soon as intra‐cluster correlation is present Even in the univariate case, the new test can be very competitive for Gaussian data. Furthermore, the statistic is easy to compute, even for large dimensional data. The author shows through simulations that his test performs well compared to the average‐based test. He illustrates its use with real data.     

略论邓小平理论萌芽的界定及其标志

作为邓小平理论萌芽的标志不是某一具体的时间、论著、观点。对邓小平理论萌芽应作出系统的、全面的科学界定。邓小平理论萌芽的标志应该是时间段、论著链、观点网     

农产品电商集群企业地理邻近性对协同创新绩效的影响

基于知识治理视角,构建农产品电商集群企业地理邻近性、知识治理、知识共享和协同创新绩效关系的链式中介模型,并引入网络关系强度作为调节变量,结合341家农产品电商集群企业的调研数据,采用多层次回归和Bootstrap分析方法,分析地理邻近性对协同创新绩效的直接作用,检验知识治理和知识共享的独立中介作用和链式中介作用,以及网络关系强度的调节作用。结果表明：地理邻近性正向影响协同创新绩效;知识治理在地理邻近性和协同创新绩效间发挥中介作用;知识共享在知识治理和协同创新绩效间发挥中介作用;知识治理和知识共享在地理邻近性和协同创新绩效间发挥链式中介作用;网络关系强度正向调节正式知识治理和显性知识共享的链式中介作用。因此,农产品电商集群企业要把握数字经济发展契机,善于利用集群区位优势和产业资源,激发正式知识治理和非正式知识治理的双重效应,与合作企业建立良好的知识共享关系,实现高质量协同创新发展。     

Sampling from spatial databases

This paper deals with techniques for obtaining random point samples from spatial databases. We seek random points from a continuous domain (usually ²) which satisfy a spatial predicate that is represented in the database as a collection of polygons. Several applications of spatial sampling (e.g. environmental monitoring, agronomy, forestry, etc) are described. Sampling problems are characterized in terms of two key parameters: coverage (selectivity), and expected stabbing number (overlap). We discuss two fundamental approaches to sampling with spatial predicates, depending on whether we sample first or evaluate the predicate first. The approaches are described in the context of both quadtrees and R-trees, detailing the sample first, acceptance/rejection tree, and partial area tree algorithms. A sequential algorithm, the one-pass spatial reservoir algorithm is also described. The relative performance of the various sampling algorithms is compared and choice of preferred algorithms is suggested. We conclude with a short discussion of possible extensions.     

ＧＩＳ技术支持下的北宋初期丝路要道灵州道复原研究

在９世纪后半叶乃至整个１０世纪的丝绸之路东、中段交通网络系统中，灵州道占有一席之地。宋初，大食、回鹘、于阗以及归义军等民族政权多通过灵州道与北宋王朝进行经贸、文化往来。本文主要针对这一时段内灵州道的畅通情况及其道路性质进行探讨，在原有文献考证的基础上，利用考古资料、ＧＩＳ技术，尽可能实现对灵州道古地名数据的精确地理定位，最后使用ＡＲＣＧＩＳ技术，绘制灵州道的道路走向地图，为北宋灵州道区域的政治、经济、文化交流综合研究提供地理学依据。     

清代广西三界庙地理分布与三界神信仰探析

三界庙在清代广西各府中都有分布,主要集中分布在南宁、浔州、郁林、平乐、梧州等五府(州),呈现出一种沿着西江流域自东向西递减的分布规律,在郁江两岸分布最为密集。清代广西已经初步形成了三界神祭祀圈,而这种祭祀圈的出现与三界神的现实功利色彩有着密不可分的关系。     

Sign Restrictions,Structural Vector Autoregressions,and Useful Prior Information

This paper makes the following original contributions to the literature. (i) We develop a simpler analytical characterization and numerical algorithm for Bayesian inference in structural vector autoregressions (VARs) that can be used for models that are overidentified, just‐identified, or underidentified. (ii) We analyze the asymptotic properties of Bayesian inference and show that in the underidentified case, the asymptotic posterior distribution of contemporaneous coefficients in an n‐variable VAR is confined to the set of values that orthogonalize the population variance–covariance matrix of ordinary least squares residuals, with the height of the posterior proportional to the height of the prior at any point within that set. For example, in a bivariate VAR for supply and demand identified solely by sign restrictions, if the population correlation between the VAR residuals is positive, then even if one has available an infinite sample of data, any inference about the demand elasticity is coming exclusively from the prior distribution. (iii) We provide analytical characterizations of the informative prior distributions for impulse‐response functions that are implicit in the traditional sign‐restriction approach to VARs, and we note, as a special case of result (ii), that the influence of these priors does not vanish asymptotically. (iv) We illustrate how Bayesian inference with informative priors can be both a strict generalization and an unambiguous improvement over frequentist inference in just‐identified models. (v) We propose that researchers need to explicitly acknowledge and defend the role of prior beliefs in influencing structural conclusions and we illustrate how this could be done using a simple model of the U.S. labor market.