The geometric realization of a simplicial Hausdorff space is Hausdorff

It is shown that the thin geometric realization of a simplicial Hausdorff space is Hausdorff. This proves a famous claim by Graeme Segal that the thin geometric realisation of a simplicial k-space is a k-space.Comment: 19 page

A Semantic Framework for Priority-based Service Matching in Pervasive Environments

The increasing popularity of personal wireless devices has raised new demands for the efficient discovery of heterogeneous devices and services in pervasive environments. The existing approaches such as Jini [1], UPnP [8], etc., describe services at a syntactic level and the matching mechanisms in these approaches are limited to syntactic comparisons based on attributes or interfaces. In order to overcome the limitations in these approaches, there has been an increased interest in the use of semantic description and matching techniques to support effective service discovery. This paper proposes a semantic matching approach which facilitates the discovery of device-based services in a pervasive environment; the approach provides a ranking facility that orders services according to their suitability and also considers priorities placed on individual requirements in a request during the matching process. The evaluation studies have shown that the matcher results correlate reasonably well with human judgement

Elections, Ideology, and Turnover in the U.S. Federal Government

A defining feature of public sector employment is the regular change in elected leadership. Yet, we know little about how elections influence public sector careers. We describe how elections alter policy outputs and disrupt the influence of civil servants over agency decisions. These changes shape the career choices of employees motivated by policy, influence, and wages. Using new Office of Personnel Management data on the careers of millions of federal employees between 1988 and 2011, we evaluate how elections influence employee turnover decisions. We find that presidential elections increase departure rates of career senior employees, particularly in agencies with divergent views relative to the new president and at the start of presidential terms. We also find suggestive evidence that vacancies in high-level positions after elections may induce lower-level executives to stay longer in hopes of advancing. We conclude with implications of our findings for public policy, presidential politics, and public management

A Semantic Approach for Description and Ranked Matching of Services in Pervasive Environments

With the recent developments in technology, new and diverse devices are being introduced into the pervasive world. This has raised new challenges for the discovery of devices and their services in dynamic environments. The existing approaches such as Jini [AOSJ99], UPnP [UPnP06], etc., describe services at a syntactic level and the matching mechanisms in these approaches are limited to syntactic comparisons based on attributes or interfaces. In order to overcome the limitations of these approaches, there has been an increasing interest in the use of Semantic Web technologies to support the description and matching of services. This paper proposes a semantic matching framework to facilitate effective discovery of device based services in pervasive environments. This offers a ranking mechanism that will order the available services in the order of their suitability; the evaluation of the experimental results have indicated that the results correlate well with human perception

Public Sector Personnel Economics: Wages, Promotions, and the Competence-Control Trade-off

We model personnel policies in public agencies, examining how wages and promotion standards can partially offset a fundamental contracting problem: the inability of public sector workers to contract on performance, and the inability of political masters to contract on forbearance from meddling. Despite the dual contracting problem, properly constructed personnel policies can encourage intrinsically motivated public sector employees to invest in expertise, seek promotion, remain in the public sector, and develop policy projects. However, doing so requires internal personnel policies that sort slackers from zealots. Personnel policies that accomplish this task are quite different in agencies where acquired expertise has little value in the private sector, and agencies where acquired expertise commands a premium in the private sector. Finally, even with well-designed personnel policies, there remains an inescapable trade-off between political control and expertise acquisition