$$D_s$$-optimality in copula models

Optimum experimental design theory has recently been extended for parameter estimation in copula models. The use of these models allows one to gain in flexibility by considering the model parameter set split into marginal and dependence parameters. However, this separation also leads to the natural issue of estimating only a subset of all model parameters. In this work, we treat this problem with the application of the \(D_s\)-optimality to copula models. First, we provide an extension of the corresponding equivalence theory. Then, we analyze a wide range of flexible copula models to highlight the usefulness of \(D_s\)-optimality in many possible scenarios. Finally, we discuss how the usage of the introduced design criterion also relates to the more general issue of copula selection and optimal design for model discrimination.     

Central State Steering of Local Collaboration: Assessing the Impact of Tools of Meta-governance in Homelessness Services in England

Much of the discussion of state steering of service delivery networks to encourage collaboration at the local level has been theoretical. This study builds on this analysis systematically to assess the relationship between meta-governance tools of central government steering and the extent of local collaboration, using the case of homelessness services in England. Contrary to the pessimist expectations of some contemporary theory, central government funding tools and facilitating the transfer of best practice encourages collaboration. However, simple information provision and authority based tools are only partially effective, risking tokenistic compliance. Authority tools are more effective when combined with other tools.

Accountability in the Shadow of Hierarchy: The Horizontal Accountability of Agencies

In the Netherlands, new accountability arrangements are created as remedies for the accountability deficit of agencies. These arrangements are of a ‘horizontal’ nature, as the agencies account for their behaviour towards accountees that are not their hierarchical superiors: clients, stakeholders or peers. This paper provides an inventory and qualitative assessment of horizontal accountability arrangements. It is argued that they have added value because they stimulate learning. However, horizontal accountability is not a substitute for hierarchical accountability. Horizontal accountability arrangements operate ‘in the shadow of hierarchy’: they gain significance through complex interactions with traditional forms of accountability.

Citizen Support for Hospital Privatization: A Hierarchical Cross-National Analysis

The movement for a new public management (NPM) holds that citizens will put aside partisan and ideological differences to support more efficient service delivery. Focusing on hospital privatization, a multi-national sample is utilized to investigate this assertion. Generalized hierarchical linear modeling (GHLM) is employed as the method of statistical analysis. The findings with regard to privatizing hospitals reveal that citizens develop their policy position by reference to a combination of symbolic political variables, service demand, self-interest, information levels, and political efficacy. The results cast doubt on the assertion that partisan differences will be set aside as citizens consider privatization reforms.

Quo Vadis? Suggestions for future corporate governance research

In this paper I first review the basic tenets of agency theory and theory of managerial capitalism as well as some of the major research in these areas then suggest for areas for future research that go beyond the extant empirical work. First, I suggest that it would be useful to reconsider the basic nature of the agency relationship, taking into account that while equity holders can be considered the principal, the board of directors may be more realistically in need of agent-like controls. Second, the complementary or supplementary nature of the monitoring/incentive alignment relationship has been shown theoretically but the empirical evidence is equivocal and needs future investigation. Third, there has been very limited research on the construct validity of archival measures of the sort used in agency theory. This requires the use of methodologies outside those of the more conventional type used in agency theory (i.e., from economics and finance). Finally, agency theory development would profit greatly by more extensive use of research methods such as laboratory studies and survey methodology and the integration of concepts such as personality and control processes.

A quadratic lower bound for colourful simplicial depth

We show that any point in the convex hull of each of (d+1) sets of (d+1) points in ℝ ^d is contained in at least ⌊(d+2)²/4⌋ simplices with one vertex from each set. Both authors were supported by NSERC Discovery grants. Additionally, T. Stephen was supported by DFG FG-468 and the Dynamical Systems research focus at the University of Magdeburg.     

Online scheduling on parallel machines with two GoS levels

This paper investigates the online scheduling problem on parallel and identical machines with a new feature that service requests from various customers are entitled to many different grade of service (GoS) levels. Hence each job and machine are labeled with the GoS levels, and each job can be processed by a particular machine only when the GoS level of the job is not less than that of the machine. The goal is to minimize the makespan. In this paper, we consider the problem with two GoS levels. It assumes that the GoS levels of the first k machines and the last m−k machines are 1 and 2, respectively. And every job has a GoS level of 1 alternatively or 2. We first prove the lower bound of the problem under consideration is at least 2. Then we discuss the performance of algorithm AW presented in Azar et al. (J. Algorithms 18:221–237, 1995) for the problem and show it has a tight bound of 4−1/m. Finally, we present an approximation algorithm with competitive ratio . Research supported by Natural Science Foundation of Zhejiang Province (Y605316) and its preliminary version appeared in Proceedings of AAIM2006, LNCS, 4041, 11-21.     

Diesseits von Coaching und Mentoring: Kollegiale Praxisberatung

Zusammenfassung  Die Methode der kollegialen Beratung eignet sich gut für Menschen in Organisationen, die vor der Herausforderung stehen, ihr Prozesswissen in neuen, unbekannten Kontexten anzuwenden. Schnelligkeit und konkreter Praxisbezug sind dabei wesentliche Faktoren für eine akzeptierte Lernform. In diesem Artikel wird eine Anpassung der Grundmethode der kollegialen Beratung, die kollegiale Praxisberatung, vorgestellt, die diese Anforderung der Praktiker erfüllt. Die dabei auftretenden Prozesswirkungen und Lernerfahrungen werden anhand zweier Praxisbeispiele aus der Industrie illustriert und Chancen sowie Grenzen der Methode diskutiert.

A survey on nonadaptive group testing algorithms through the angle of decoding

Group testing, sometimes called pooling design, has been applied to a variety of problems such as blood testing, multiple access communication, coding theory, among others. Recently, screening experiments in molecular biology has become the most important application. In this paper, we review several models in this application by focusing on decoding, namely, giving a comparative study of how the problem is solved in each of these models.