电子商务模式决策的支持模型设计

借助潜在需求这一概念提出决策分析框架,帮助决策者在决策制定的最初分析阶段排除那些与本企业环境和供应链条件不相容的电子商务模式;旨在为电子商务从业者和研究人员提供一个实施电子商务模式决策分析时的支持模型.     

Tree health mapping with multispectral remote sensing data at UC Davis, California

Tree health is a critical parameter for evaluating urban ecosystem health and sustainability. Traditionally, this parameter has been derived from field surveys. We used multispectral remote sensing data and GIS techniques to determine tree health at the University of California, Davis. The study area (363 ha) contained 8,962 trees of 215 species. Tree health conditions were mapped for each physiognomic type at two scales: pixel and whole tree. At the pixel scale, each tree pixel within the tree crown was classified as either healthy or unhealthy based on vegetation index values. At the whole tree scale, raster based statistical analysis was used to calculate tree health index which is the ratio of healthy pixels to entire tree pixels within the tree crown. The tree was classified as healthy if the index was greater than 70%. Accuracy was checked against a random sample of 1,186 trees. At the whole tree level, 86% of campus trees were classified as healthy with 88% mapping accuracy. At the pixel level, 86% of the campus tree cover was classified as healthy. This tree health evaluation approach allows managers to identify the location of unhealthy trees for further diagnosis and treatment. It can be used to track the spread of disease and monitor seasonal or annual changes in tree health. Also, it provides tree health information that is fundamental to modeling and analysis of the environmental, social, and economic services produced by urban forests.     

Consortium for Atlantic Regional Assessment: Information Tools for Community Adaptation to Changes in Climate or Land Use

To inform local and regional decisions about protecting short-term and long-term quality of life, the Consortium for Atlantic Regional Assessment (CARA) provides data and tools (for the northeastern United States) that can help decision makers understand how outcomes of their decisions could be affected by potential changes in both climate and land use. On an interactive, user-friendly website, CARA has amassed data on climate (historical records and future projections for seven global climate models), land cover, and socioeconomic and environmental variables, along with tools to help decision makers tailor the data for their own decision types and locations. CARA Advisory Council stakeholders help identify what information and tools stakeholders would find most useful and how to present these; they also provide in-depth feedback for subregion case studies. General lessons include: (1) decision makers want detailed local projections for periods short enough to account for extreme events, in contrast to the broader spatial and temporal observations and projections that are available or consistent at a regional level; (2) stakeholders will not use such a website unless it is visually appealing and easy to find the information they want; (3) some stakeholders need background while others want to go immediately to data, and some want maps while others want text or tables. This article also compares what has been learned across case studies of Cape May County, New Jersey, Cape Cod, Massachusetts, and Hampton Roads, Virginia, relating specifically to sea-level rise. Lessons include: (1) groups can be affected differently by physical dangers compared with economic dangers; (2) decisions will differ according to decision makers' preferences about waiting and risk tolerance; (3) future scenarios and maps can help assess the impacts of dangers to emergency evacuation routes, homes, and infrastructure, and the natural environment; (4) residents' and decision makers' perceptions are affected by information about potential local impacts from global climate change.     

A circular-cone test for testing homogeneity against a simple tree order

Several methods exist for the problem of testing the equality of several treatments against the one-sided alternative that the treatments are better than the control. These methods include Dunnett's test, Bartholomew's likelihood-ratio test, the Abelson-Tukey-Schaafsma-Smid optimal-contrast test, and the multiple-contrast test of Mukerjee, Robertson, and Wright. A new test is proposed based on an approximation of the likelihood-ratio test of Bartholomew. This test involves using a circular cone in place of the alternative-hypothesis cone. The circular-cone test has excellent power characteristics similar to those of Bartholomew's test. Moreover, it has the advantages of being simpler to compute and may be used with unequal sample sizes.     

Professional Perspectives on Decision Making about the Long-term Care of Older People

With the increasing pressure on social and health care resources,professionals have to be more explicit in their decision makingregarding the long-term care of older people. This groundedtheory study used 19 focus groups and nine semi-structured interviews(99 staff in total) to explore professional perspectives onthis decision making. Focus group participants and intervieweescomprised care managers, social workers, consultant geriatricians,general medical practitioners, community nurses, home care managers,occupational therapists and hospital discharge support staff.The emerging themes spanned context, clients, families and services.Decisions were often prompted by a crisis, hindering professionalsseeking to make a measured assessment. Fear of burglary andassault, and the willingness and availability of family to helpwere major factors in decisions about living at home. Serviceavailability in terms of public funding for community care,the availability of home care workers and workload pressureson primary care services influenced decision ‘thresholds’regarding admission to institutional care. Assessment toolsdesigned to assist decision making about the long-term careof older people need to take into account the critical aspectsof individual fears and motivation, family support and the availabilityof publicly funded services as well as functional and medicalneeds.     

高技术园区技术效率与规模指数——基于DEA的实证研究

文章运用数据包络分析法评价了53个国家级开发区的投入产出效率、投入剩余和产出亏空状况,同时以超效率DEA模型为基础对这些开发区的生产效率进行综合排名,最后通过线性回归探讨影响投入产出的纯技术效率和规模指数的外部因素。结果发现:(1)在众多的开发区中真正处于有效率生产状态的地区并不多,占20.75%,处于纯技术有效的开发区占39.62%;(2)导致大部分开发区无法处于有效的生产前沿面上进行生产的最直接的原因是规模过小;(3)开发区的投入产出纯技术效率受地区的开放程度、集聚程度和气候环境的影响较大,而规模指数则受开放程度、地区经济实力和政府政策的影响较为明显。     

基础产业集团企业在投资决策中的博弈分析

我国基础产业具有明显寡头垄断的行业特点,这些产业中的集团企业在投资决策中的一些行为可以博弈论的观点进行合理解释。本文在分析这些特点的基础上,建立了一个数学模型,对我国基础产业集团企业决策的博弈过程进行了描述,并利用该模型分析了集团企业的投资行为。分析结果表明,该模型较好地反映了我国基础产业集团企业投资决策过程中的一些现象,并使这些现象得到了经济学意义上的合理解释。     

Interpersonal dependency of preferences

Standard decision theoretic models disregard the phenomenon of interpersonal dependency of preferences. In this paper it is argued that interpersonal dependency of preferences is a serious challenge for standard utility theory. First we sketch the more philosophical aspects of the problem and then, using a simple, formal model for the two-person case, we show that interpersonal dependency of preferences generally results in indeterminacy of preferences (resp. of subjective utility).     

Jensen不等式在导出和证明几何不等式中的应用

本文给出 Jensen 不等式在导出和证明几何不等式中的应用,揭示出一些几何不等式的来历及寻求证明的技巧。     

三叉判定树与伪币问题

对伪币问题提出了三叉判定树方法,并在计算机上给予验证。