La médiane simpliciale d'Oja: Existence,unicité et stabilité

Oja (1983) examined various ways of measuring location, scatter, skewness, and kurtosis for multivariate distributions. Among other measures of location, he introduced a generalised median known in this paper under the name of the Oja median. In our study of the existence of that median, we show that Oja's definition can only be applied to distributions having a mean. In dimension d θ 2, we establish that the usual method of extension breaks down, which raises the question of the validity of the concept as a notion of median. Two fundamental theoretical properties of that median are also considered: uniqueness and consistency.     

A probablistic analysis for an optimal screening problem

Summary We consider a lotL formed byN apparently similar unitsW ₁,…,W _N, where each of theW _i may come from one of two different populationsP ₁ andP ₂;T ₁,…,T _N denote the corresponding lifetimes. The units fromP _i undergo a failure of kindi and their survival function isS _i (t). We assume that the failure rate function are known and that the units fromP ₁ are ?substandard?: λ ₁ (t)≥λ ₂ (t), ∀t≥0. We want to putW ₁,…,W _N under a pre-operational test (burn-in test) in order to eliminate at least a great part of the substandard units and we face the problem of obtaining a rule for stopping the test under the assumption that, with the failure of a unit, it is possible to recognize the population from which the unit comes. Such a problem will be formalized as an optimal stopping problem for a suitably defined Markov process. Our study shall evidentiate some fundamental aspects of the problem and the role of the prior distribution of the (random) numberM ₀ of those units inL coming fromP ₁ (substandard). The latter distribution has a great influence on the form of the solution. This research was supported by the C.N.R. Project ?Statistica Bayesiana e Simulazione in Affidalità e Modellistica Biologica?.     

Program analysis using the client oriented cost outcome system.

The client oriented cost outcome system has been under development in Pennsylvania community and hospital programs since 1972. The system builds upon the behavioral and decision data generated with or on behalf of consumers. Flexibility for local program system design is permitted if the procedures of consumer intake, review, and termination document each consumer's (a) problems, resources, and goals, (b) overall functioning level in their ordinary community, and (c) services intended and rendered as related to (a), above. While the system's primary application is in providing feedback for local program quality assurance and evaluation procedures, aggregation of data permits program planning and evaluation at county, state, and federal levels in terms of (a) client demographic or diagnostic characteristics, and (b) program service characteristics and objectives.     

Involving constituents in agency priority setting: a case study

Many government agencies have "constituents" who believe the agencies should hear and consider their needs and desires in establishing program priorities. This article describes how one involves interested constituents (consumers, industry, medical professionals, and state organizations) in the agency's annual priority-setting process. This participation has produced a number of beneficial results-some expected and some unexpected.     

Personal income taxation under mobility, exogenous and endogenous welfare weights, and asymmetric information

This paper analyses how governments should tax labour income accruing to a group of highly skilled and geographically mobile individuals who divide their time or career between several jurisdictions. The analysis differs from previous models on migration and taxation by addressing optimal regulation when agents work for several principals. Optimal taxation is developed for social welfare functions with exogenous and endogenous welfare weights. Marginal income taxes are applied for screening purposes, and the rates are lower with endogenous than with exogenous welfare weights. Received: 22 January 1998/Accepted: 3 July 1999)     

The governance of social enterprises: Mission drift and accountability challenges in hybrid organizations

We examine the challenges of governance facing organizations that pursue a social mission through the use of market mechanisms. These hybrid organizations, often referred to as social enterprises, combine aspects of both charity and business at their core. In this paper we distinguish between two ideal types of such hybrids, differentiated and integrated, and we conceptualize two key challenges of governance they face: accountability for dual performance objectives and accountability to multiple principal stakeholders. We revisit the potential and limitations of recently introduced legal forms to address these challenges. We then theorize about the importance of organizational governance and the role of governing boards in particular, in prioritizing and aligning potentially conflicting objectives and interests in order to avoid mission drift and to maintain organizational hybridity in social enterprises. Finally, we discuss future research directions and the implications of this work for rethinking traditional categories of organizations, namely business and charity.     

THE BALANCED US PRESS

We measure the relative ideological positions of newspapers, voters, interest groups, and political parties, using data on ballot propositions. We exploit the fact that newspapers, parties, and interest groups take positions on these propositions, and the fact that citizens ultimately vote on them. We find that, on average, newspapers in the United States are located almost exactly at the median voter in their states—that is, they are balanced around the median voter. Still, there is a significant amount of ideological heterogeneity across newspapers, which is smaller than the one found for interest groups. However, when we group propositions by issue area, we find a sizable amount of ideological imbalance: broadly speaking, newspapers are to the left of the state‐level median voter on many social issues, and to the right on many economic issues. To complete the picture, we use two existing methods of measuring bias and show that the news and editorial sections of newspapers have almost identical partisan positions.     

方法论意义上的《中国之欧洲》--兼及比较诗学研究的一种启示

艾田蒲（ Rene Etiemble）的比较文化巨著《中国之欧洲》具有独特的方法论体系。在语言层面上，这部著作表现出形象性与思辨性的高度统一；逻辑层面上则以归谬法的使用为特色；论述策略上忠实体现了作者提出的“比较诗学”的特性---历史考证与审美思考的结合；结构层面上则倾向于“起-承-转-合”的完整运思。这一独特的方法论体系或许可以为比较诗学的研究提供一种启示：既然从意识层面入手解决各类“中心主义”、民族主义困难重重，从学理层面进行的辨析又常常陷入曲高和寡的窘境，那么，以方法的运作清除偏见所赖以滋生的土壤，或许可以为我们带来一种真正清醒、公正而又不失美感的比较诗学。     

A powerful and efficient algorithm for breaking the links between aliased effects in asymmetric designs

Fractional factorial (FF) designs are no doubt the most widely used designs in experimental investigations due to their efficient use of experimental runs. One price we pay for using FF designs is, clearly, our inability to obtain estimates of some important effects (main effects or second order interactions) that are separate from estimates of other effects (usually higher order interactions). When the estimate of an effect also includes the influence of one or more other effects the effects are said to be aliased. Folding over an FF design is a method for breaking the links between aliased effects in a design. The question is, how do we define the foldover structure for asymmetric FF designs, whether regular or nonregular? How do we choose the optimal foldover plan? How do we use optimal foldover plans to construct combined designs which have better capability of estimating lower order effects? The main objective of the present paper is to provide answers to these questions. Using the new results in this paper as benchmarks, we can implement a powerful and efficient algorithm for finding optimal foldover plans which can be used to break links between aliased effects.