北极海域法律地位争端及其解决

关于北美大陆北部毗邻的北极海域法律地位,加拿大与美国等国家各执一辞。前者主要依据其对“直线基线”和“历史性所有权”的理解。后者认为,不应依据过去的气候、地理、水文等状况来判断,全球气候的变暖,冰层的变薄或者消失,将使北极海域冰层的法律地位发生质的改变。北美大陆北部毗邻的北极海域法律地位争端如何解决？“北极南极化”的观点不可行,化解现有北极条约之间的冲突是解决北极海域法律地位争端的前置问题。北极区域的环境保护应提升到国际合作的程度,敦促各国就北极海域环境保护达成协议;各国在北极海域的问题上加强合作十分必要;我国应积极参与北极事务。     

ANALYSIS OF A GI/G Y /1 SYSTEM IN DISCRETE-TIME

ABSTRACT

We consider a class of single server queueing systems in which customers arrive singly and service is provided in batches, depending on the number of customers waiting when the server becomes free. Service is independent of the batch size. This system could also be considered as a batch service queue in which a server visits the queue at arbitrary times and collects a batch of waiting customers for service, or waits for a customer to arrive if there are no waiting customers. A waiting server immediately collects and processes the first arriving customer. The system is considered in discrete time. The interarrival times of customers and the inter-visit times of the server, which we call the service time, have general distributions and are represented as remaining time Markov chains. We analyze this system using the matrix-geometric method and show that the resulting R matrix can be determined explicitly in some special cases and the stationary distributions are known semi-explicitly in some other special cases.     

Extended tables of the distribution of friedman’ s s-statistic in the two-way layout

Friedman’s (1937, 1940) S-statistic is designed to test the hypothesis that there is no treatment effect in a randomized-block design with k treatments and n blocks. In this paper we give tables of the null distribution of S for k = 5, n = 6(1)8, and for k = 6, n = 2(1)6. Computational details are discussed.     

Mixture experiments with process variables: d-optimal orthogonal experimental designs

Blending experiments with mixture in the presence of process variables are considered. We present an experimental design for quadratic (or linear) blending. The design in two orthogonal blocks is D-optimized in the case where there are no restrictions on the blending in two orthogonal blocks is presented when there are arbitrary restrictions on the blending components. The pair of orthogonal blocks can be used with and arbitrary number of process variables. The number of design points needed when different orthogonal blocks are used is usually smaller than when a single block is repeated at the various process variables levels.     

略谈"西口文化"的基本特征

"西口文化"具有源远流长的历史性特征;具有草原文化与晋、陕文化有机结合的复合文化特征;具有商业文化的显著特征;"西口文化"基础深厚,具有广泛的群众性;具有与时俱进的开拓性.     

基于ECSI修正模型的历史街区游客满意度研究*

游客满意度直接影响历史街区旅游开发成效与可持续发展,是旅游研究的热点问题。欧洲顾客满意度模型ECSI是研究顾客满意度的经典模型,基于两个历史街区的实证数据,文章对ECSI进行修正并构建了历史街区游客满意度模型HBTSI,遴选出5个潜在变量和20个观测变量构建了评价指标体系。文章选择成都宽窄巷子和锦里作为样本案例,对HBTSI模型进行了实证检验。研究发现,历史街区形象认知与游客期望、游客感知价值存在显著相关性,但无法直接影响游客满意度。游客期望与游客感知价值之间不存在显著相关,而是通过直接作用于游客感知质量间接影响游客满意度,游客满意度与游客忠诚度之间存在相关关系。     

旧城更新叙事的权力维度和理念维度——以上海“田子坊”为例

过去二十年,上海旧城改造最有名的项目之一是田子坊。田子坊做得有声有色,却非一帆风顺,它曾多次面临被拆迁的危机。田子坊求生存的斗争既是政府内部关乎开发主导的权力之争,更是城市更新的模式之争和城市发展的理念之争。田子坊实验的艰难,在于它是从政府内部对城市更新主导模式的认真质疑,及对更好兼顾城市文脉、创新产业、居民利益和社会公正的包容性改造新模式的真诚实践。田子坊可能成为孤独的成功者,但田子坊的经验和原则不应成为孤案,而应得到充分的肯定并在未来城市的更新中得以大力地推广。     

Block response-adaptive randomization in clinical trials with binary endpoints

In a clinical trial, response-adaptive randomization (RAR) uses accumulating data to weigh the randomization of remaining patients in favour of the better performing treatment. The aim is to reduce the number of failures within the trial. However, many well-known RAR designs, in particular, the randomized play-the-winner-rule (RPWR), have a highly myopic structure which has sometimes led to unfortunate randomization sequences when used in practice. This paper introduces random permuted blocks into two RAR designs, the RPWR and sequential maximum likelihood estimation, for trials with a binary endpoint. Allocation ratios within each block are restricted to be one of 1:1, 2:1 or 3:1, preventing unfortunate randomization sequences. Exact calculations are performed to determine error rates and expected number of failures across a range of trial scenarios. The results presented show that when compared with equal allocation, block RAR designs give similar reductions in the expected number of failures to their unmodified counterparts. The reductions are typically modest under the alternative hypothesis but become more impressive if the treatment effect exceeds the clinically relevant difference.     

Designs balanced for neighbor effects in circular blocks of size six

The performance of a treatment is affected by the treatments applied to its adjacent plots, especially in the experiments of agriculture, horticulture, forestry, serology and industry. Neighbor designs ensure that treatment comparisons are least affected by neighbor effects, therefore, this is a rich field of investigation in statistics and in combinatorics. In this article, several series of neighbor balanced designs are considered in circular blocks of six units.     

关于中国当代旅游经济思想史研究的思考

中国当代旅游经济思想史研究是一个原创性课题。其所要反映的内容包括旅游经济思想的总体面貌、时代特征、理论成果、研究方法、历史价值及影响、内在规律及特点。研究的最大难点一是资料浩繁而分散,二是缺乏旅游学科独立的理论支撑。为此应以实事求是的科学态度,综合运用经济学、历史学等多学科方法,史论结合地进行研究。