Local martingales, arbitrage, and viability Free snacks and cheap thrills

Summary. We revisit a standard model of security prices as Ito processes, and provide some new economic insights about the role of arbitrage and credit limits within such a model. We show that the standard assumptions of a positive state prices and existence of an equivalent martingale measure exclude prices that are viable models of competitive equilibrium and that are potentially useful for modeling actual financial markets. These models have been dismissed in the past as allowing arbitrage, but in fact an agent who prefers more to less and who has limited access to credit may have an optimum. Received: June 9, 1999; revised version: October 4, 1999     

高层住宅建筑施工中防渗漏技术的应用

高层住宅建筑施工越来越多,住宅用户对于建筑的质量要求越来越高,一旦出现渗漏的现象,将会造成用户的不满,而且影响到了高层建筑住宅上的信誉和形象,需要加强对防渗漏施工技术的有效应用,才能够避免出现渗漏的现象,从而保证高层住宅施工的总体质量.本文主要围绕高层建筑防渗漏施工技术的应用整改问题和论述,主要是结合高层住宅建筑的各个...     

粮食挂壁的原因分析及预防措施

粮食挂壁是由于粮堆内部湿热传导异常或粮堆与外界湿热传导异常,粮堆内局部水分较高和热量聚集粮食发热霉变形成的。文章分析了常见易发生挂壁的情形及预防措施,主要从仓房防潮性、隔热性、粮食水分变化、储粮微生物及害虫、粮食杂质聚集、异常粮情处理等方面进行分析,并提出了相应解决对策。     

论当前形势下食品抽检监测与食品安全

当前食品安全事关人们的身体健康,食品抽检监测质量与食品安全问题已经引发全社会的关注和重视。本文主要讨论了当前形势下抽检监测对于食品安全的重要意义。针对我国存在的食品安全主要问题展开分析,针对现存问题采取科学、有序的食品抽检监测措施,为保障人们的生命安全和健康做出积极贡献。     

我国粮食产后损失情况概述

本文系统分析了粮食产后各环节损失的原因及损失量,针对相关粮食损失原因及状况,提出了减少粮食产后损失的措施及建议,以期为我国实现节粮减损提供支持。     

针对产品生产和加工方法贸易措施的违法性分析

在GATT—WTO体系内部,针对产品生产和加工方法贸易措施的合法性,以及如何规范允许使用的针对产品生产和加工方法贸易措施的讨论甚为激烈,成为最有争议的焦点问题之一。本文根据对WTO协议中的GATT第1条、第3条、第20条,以及《技术性贸易壁垒协议》相关条文和案例的研究,分析了针对产品生产和加工方法贸易措施的违法性及其可能的负面效应,以供进一步的研究参考。     

基于空间信息重构技术的东北三省大豆时空演变研究（1980—2010年）

［目的］东北三省是我国大豆生产的重要基地，也是国家种植结构调整的重点区域。研究分析了1980—2010年东北三省大豆时空演变特征，为合理制定种植结构调整政策、加快推进农业供给侧结构性改革提供科学的空间信息参考。［方法］综合卫星遥感技术和空间信息重构模型优势，基于交叉信息熵方法，构建了作物空间信息重构模型SPAM China，对1980—2010年东北三省大豆种植空间分布、时空演变、重心迁移等进行了研究。［结果］1980—2010年东北三省大豆种植区域小幅增加，大豆种植面积栅格数量从6 703个增加至7 214个，松嫩平原、三江平原以及吉林省中部地区是东北三省的大豆主产区； 种植面积大幅增加，单位栅格面积增加1 000hm2以上的栅格数量增加明显，面积增加区域主要位于北纬47°~50°之间和东经1255°~131°之间； 东北三省大豆种植面积重心分别向东迁移10620km，向北迁移20857km，辽宁省、吉林省大豆种植面积重心南移，黑龙江省基本保持不变。［结论］1980—2010年东北三省大豆种植面积空间分布小幅增加，但时空变化特征显著，种植面积重心向北向东迁移。     

A correlated uniqueness model of service quality measurement among users of cloud-based service platforms

This research furthers understanding of whether consumers of cloud-based service platforms can distinguish between gap theory dimensions (i.e., expectation and performance) on these platforms. We build upon and extend the work of (Natesan and Aerts, 2016) by applying confirmatory factor analysis on gap scores from survey data to develop and test an improved approach of measuring service system quality in cloud-based service platforms. Using the IS-adapted SERVQUAL instrument, we apply the correlated uniqueness model, which is part of the multitrait-multimethod (MTMM) framework, to evaluate the validity of using GAP scores and account for the effect of the method. There is significant support for method effects as shown by our suggested model paths in the trait convergent validity model with medium-large factor coefficients. Additionally, the fit of the correlated uniqueness model indicates respondents can distinguish between the gap theory dimensions of the IS-adapted SERVQUAL instrument. The praxis of service quality measurement could benefit by using our measurement approach of incorporating error correlations.     

城市土地开发约束与支持的协调度评价

研究目的：本文以浙江省为研究区，探索城市土地开发约束与支持的协调度评价新思路，并分析了城市土地开发协调度的时空分异特征。研究方法：灰色关联熵法、协调度模型。研究结果：①浙江省城市土地开发约束力强度东北部高，西南部低，支持力强度分布与之相似；②时间上：2000-2015年浙江省城市整体土地开发协调度呈现“升高—降低”的变化趋势；③空间上：浙江省城市土地开发协调度北高南低，且具有“小集中—大分散”的特征。研究结论：将协调度理论应用于城市土地开发评价中，并对土地开发约束力与支持力量化后采用灰色关联熵法建立复杂时空权重矩阵，以此建立的土地开发约束与支持的协调度评价体系具有实际价值与可操作性。     

Numeric or weighted distribution? The effect of different channel performance metrics on market share

Abstract

Previous studies have found a convex relation between weighted measures of distribution and market share for consumer products in developed economies, while companies in emerging markets often use a non-weighted (numeric) distribution measure to manage their channel strategy. In contrast to the markets with high retail concentration, the numeric distribution could be best suited to a more fragmented retail market in which the percentage of physical distribution is important. We investigate the effects of expanding numeric versus expanding weighted distribution by studying stores in channels and regions characterized by structural differences in an emerging market. Our data come from retail audits in Brazil and include 91 soft drink manufacturers, 195 brands and 1,110 stock-keeping units. Our study highlights the importance of numeric distribution as a performance measure in this market. Additionally, we show that the effects of numeric and weighted distribution on market share vary by region and channel format.