Clustering of Microarray data via Clique Partitioning

Microarrays are repositories of gene expression data that hold tremendous potential for new understanding, leading to advances in functional genomics and molecular biology. Cluster analysis (CA) is an early step in the exploration of such data that is useful for purposes of data reduction, exposing hidden patterns, and the generation of hypotheses regarding the relationship between genes and phenotypes. In this paper we present a new model for the clique partitioning problem and illustrate how it can be used to perform cluster analysis in this setting.     

On 3-Stage Clos Networks with Different Nonblocking Requirements on Two Types of Calls

Hwang and Lin introduced a new nonblocking requirement for 2-cast traffic which imposes different requirements on different types of coexisting calls. The requirement is strictly nonblocking for point-to-point calls among the 2-cast traffic, and is rearrangeable for genuine 2-cast calls. They conjectured that the 3-stage Clos network C(n,n,r,r,2n) satisfies the above requirement. We prove that C(n,n,4,r,2n) satisfies the above requirement.Supported in part by NSC91-2115-M009-002.Supported in part by the National Science Council under grant NSC91-2115-M009-010 and by the Li-Li-Tai-Yang Network Research Center of National Chiao Tung University.     

Evaluating the Evaluators: Should Investors Trust Corporate Governance Metrics Ratings?

Companies are under increasing pressure to have their corporate governance rated by an independent corporate governance metrics firm, such as Institutional Shareholder Services (ISS) or Governance Metrics International (GMI). These rating firms claim to be able to determine how effective and responsive a company’s board is. Institutional investors have begun using these board governance ratings when deciding which firms to include in their stock portfolios. This paper considers whether investors, many of whom claim to be socially responsible, should be relying upon board governance metrics. We find that these metrics are not good indicators of either the quality of a firm’s earnings or of its ethics.     

Community is not a Place but a Relationship<Superscript>1</Superscript>: Lessons for Organizational Development

The premise of this article is that organizations need to be “organized” differently if we want to re-invigorate the power of community in contemporary life. A central theme within the current reform movement toward restorative justice is the devolution of authority from formal governmental systems to community. In order to effectively socialize young people, communities and families must perform certain functions well. As more and more societal activities take place within organizations, we face the dilemma that the weakened communities create a demand for increasing involvement of public organizations in the life of the community. Yet modern organizations do not effectively perform functions unique to families and communities. Drawing on insights from a unique community-system partnership in restorative peacemaking circles, this paper argues we may need to reinvent our organizations so that they learn to behave as members of the community. ¹This apt phrase and fundamental insight about the meaning of community came from the seminal article by Paul McCold and Benjamin Wachtel (1998).     

How Many Balance Functions Does it Take to Determine a Utility Function?

Call b your balance function at wealth W if you are indifferent between W and a 50–50 lottery with outcomes x and b(x). Given one b, u is arbitrary on one side of W but then determined on the other. Given two b‘s, u is arbitrary between the two W′ s but then determined elsewhere. Additional properties of u restrict the b’s but do not ordinarily make u unique. Contradictions can occur. Given three b′ s, an algorithm is developed using minimal domains of definition that determines the relative utility of the W’s. If it is irrational, then the set S generated by applying all combinations of b’s to W′ s is dense and u is determined. If finitely many b’s are rationally related, then S is discrete, a further algorithm determines it, the values of u on S are equally spaced, and u is arbitrary between any two adjacent points of S but then determined elsewhere. Infinitely many balance functions determine u unless they are rationally related in a uniform way.JEL Classification: D81     

An Empirical Investigation of the Assumptions of Risk-Value Models

Do participants make decisions consistent with risk-value tradeoffs? One hundred and five undergraduate business students made risk and preference judgments about lottery pairs in a series of paper surveys. The data indicate that the participants’ responses were generally consistent with the key assumptions of risk-value models, but that some extensions of the theory would improve this consistency. In particular, we find that modifying the risk assumptions of the risk-value theory so they are consistent the concept of the reflection of the risk attitude in the domains of gains and losses increases the agreement between the theory and the participants’ responses.     

What is Loss Aversion?

A behavioral definition of loss aversion is proposed and its implications for original and cumulative prospect theory are analyzed. Original prospect theory is in agreement with the new loss aversion condition, and there utility is capturing all effects of loss aversion. In cumulative prospect theory loss aversion is captured by both the weighting functions and the utility function. Further, some restrictions apply for the weighting functions involved in the latter model.We are indebted to Michèle Cohen and Peter Wakker for helpful comments. The suggestions of an anonymous referee have improved the presentation of the paper.