Two Stochastic Multidimensional Choice Models for Marketing Research

Two recently developed probabilistic multidimensional models for analyzing pairwise choice data are introduced, discussed in terms of their differential properties, and extended in several ways. The first one, the wandering vector model, was originally suggested by Carroll [12] and extended by De Soete and Carroll [30]. The second model, called the wandering ideal point model, is a more recently proposed [32] unfolding analog of the wandering vector model. A general maximum likelihood estimation method for fitting the various models described is mentioned, as well as a statistical test for assessing the goodness of fit. Finally, an application of the models is provided concerning consumer choice for some 14 brands of over-the-counter analgesics to illustrate how such models can be gainfully utilized for marketing decision making concerning product positioning.     

Optimal Delivery Time Quotation and Order Sequencing

This paper examines the problem of quoting a common delivery time for several orders. The decision maker responsible for the quote must trade off the cost associated with a long delivery time against the cost of tardy orders that might be induced by a short delivery time. First, an aggregate cost model is investigated where it is assumed that some cost is incurred if the quoted delivery time exceeds a given threshold and the cost of order tardiness is dependent on the order. Both exact and heuristic solution procedures are proposed for this model. Finally, for the situation where the costs cannot be quantified, a bicriteria formulation of the problem is pursued and the set of nondominated solutions is identified.     

The Future of Labour Relations in the Public Service

Abstract. During the last decade, labour relations in the public service have been subject to pressures for change, less direct, given their protected character, than in the private sector, but not less strong. The main factors of change are (only) in part common to those operating in private sector labour relations: economic constraints and budgetary restrictions, coupled with a general reaction toward the ‘public’ in general have put pressure on employment whose costs represent the major part of public expenditures; the need for greater productivity and efficiency has been increasing in order to reduce labour costs and (possibly) meet the growing demand for (social) services; technological innovations (office automation. computerization and the like) are spreading; the impact of the international competition has begun to be felt not only indirectly via constraints on the state budgets but directly in those sectors of public services which can be somehow ‘transportable’ across borders and hence exposed to foreign initiatives (public works, TLC, to some extent health services. All these factors are emphasized by the European unification process which has already introduced limits in the monetary and financial autonomy of the member states.     

Solving Resource Allocation Problems When Earning Effects Are Present

Learning effects play an important role in certain resource allocation problems, and several authors have proposed models for these problems that capture the relevant relationships. However, the models may be difficult to implement or have shortcomings in the prescribed solution procedures. In this paper, we selectively review the work to date and present a simple reformulation that facilitates solution by off-the-shelf software.     

Informal Caregiving: Dilemmas of Sandwiched Caregivers

Increased demand will intensify pressures for informal caregiving, especially for sandwiched caregivers. Using 1999, National Long Term Care Survey data, we contrasted socio-demographic statistics, care environments, activities of daily living (ADL) and instrumental activities of daily living (IADL) assistance, life quality, and employment burden of sandwiched versus non-sandwiched parental caregivers. Regression analysis explored variables influencing caregiving hours, employment accommodation, stress, strain, time for self, social life limits, free time, and excess burden. We found no differences in caregiving hours, no greater labor force accommodation, but lower quality of life among sandwiched caregivers with more than they can handle, but they undertook parent care despite quality of life reduction. Uniquely, the research indicates sandwiched caregivers’ employment mitigates stress, strain, and burden and supports policy changes providing more supportive workplace environments.

The relationship of maternal work characteristics to childcare type and quality in rural communities

Drawing on data from the Family Life Project collected in North Carolina and Pennsylvania, this paper examines the relationship between maternal work characteristics and childcare type and quality in rural communities. Research is limited on the childcare experiences of rural families. Rural areas have less access to formal childcare and families often commute long distances for work, restricting childcare options. Employed mothers using childcare were selected (n=441). Logistic and OLS regression was used to examine which characteristics, including workplace support, objective occupational measures, hours, wage, and shift, predicted care type and quality. Results indicated that most families were using informal care. Those with more hazardous work conditions and working night shifts were less likely to use centers. Higher quality care was related to more workplace support, center use, and higher wages. Implications for social policy and practice are discussed.     

Assessing the abundance of freshwater turtles in an Australian urban landscape

Although interest in the ecological impacts of urbanisation has increased, very little is known about its impacts on freshwater turtles in Australia. This study investigated the abundance and diversity of turtles in lakes in an urbanised subtropical landscape, Brisbane, Australia. It was found that turtles were abundant throughout the lakes surveyed, with four native species and one introduced species being detected. A total of 371 individuals were captured, 77.7% of which were Brisbane River turtle (Emydura macquarii signata). The lakes surveyed were estimated to support a population of 63–269 individuals for all species combined with most lake populations containing less than 100. Turtle demographics may be classed into three stages of population growth: recovery or nascent; intermediate; and climax. Turtle reproductive success is a major concern for the survival of turtles in urban areas. Continued monitoring is needed to establish if population declines are occurring. This study suggests that while turtles are persisting in this urban environment of Australia the pressures of urbanisation, such as habitat loss, increased predation on both nests and juveniles and pollution of waterways may pose on-going risks to their survival.     

China and the Different Regional Approaches in Africa

African countries have a tiny share in the international economy and are not able to play more than a small role in the International Relations arena. Nevertheless, major players are looking at Africa with a renewed interest and, among them, China seems to have the most dynamic approach in order to catch-up with other nations and upgrade relations with African countries. However, the EU is also carrying on its new strategy toward parts of Africa. In these world powers strategies, multiple approaches related to subregions exist, instead of a single regional approach. The objective of this paper is to have a closer look and to analyze how the different regions and major nations of Africa Western Africa, Egypt, Eastern Africa and South Africa) are dealing with their economic and political development path and their interconnection with other areas of the World, with an important focus on China-Africa relations.

极地环境变化——将减少炭黑排放作为保护极地以及阻止气候突变的机制

1 绪论 气候变化对北极的影响比对地球任何其他地方的影响都要更早,且更强烈.在过去的5年里,天的气温已经上升了3～4℃,1] 预计到本世纪末,地温度会上升4～7℃,冰洋的温度会上升7～10℃.但有一产业会在短期内,海冰消融中受益,就是航运业.随着北极变暖,业增长、资源开发以及包括游轮业在内的旅游业的发展,随之增长.北极航运线路的开发将降低全球航运时间和成本,短日本至英国差不多5000m的行程.过去的1个世纪里,极海洋冰块已经大晕减少,且还在继续减少,使得在北极发展航运业和加大资源开发成为现实.     

Decentralization in Linear Programming Models

This paper proposes a decomposition of a linear programming problem based on the structure of the optimal basis matrix. If this matrix contains a zero matrix of appropriate dimensions, the problem may be decomposed into a price-setting problem and a quantity-setting problem. This decomposition is valid for a set of coefficients of the problem to be determined by parametric programming. It can be applied to problems with common constraints or common variables. An application to dairy production planning is discussed and a comparison with the Dantzig-Wolfe decomposition principle is given.