Efficient Community Detection

Given a large network, local community detection aims at finding the community that contains a set of query nodes and also maximises (minimises) a goodness metric. Furthermore, due to the inconvenience or impossibility of obtaining the complete network information in many situations, the detection becomes more challenging. This problem has recently drawn intense research interest. Various goodness metrics have been proposed. And most of them base on the statistical features of community structures, such as the internal density or external spareness. However, the metrics often result in unsatisfactory results by either including irrelevant subgraphs of high density, or pulling in outliers which accidentally match the metric for the time being. Further more, when in a highly overlapping environment such as social networks, the unconventional community structures make these metrics usually end up with a quite trivial detection result. In our work, we go for a alternative point of view on the formation of the communities, namely the assembly of nodes with different roles in the structure. With the new view point, we present two metrics which are proved to perform superiorly in traditional and complex environment respectively. Moreover, on realising a single metric is whatsoever limited in effectiveness as well as scope of application, we raise up a complete framework for the collaboration ofmetrics in the field, which also lands a base-stone for future innovations. The experiment results collected from Amazon, DBLP, Youtube and LivingJournal well certifies the effectiveness of the metrics

A new dynamic algorithm for densest subhypergraphs

Computing a dense subgraph is a fundamental problem in graph mining, with a diverse set of applications ranging from electronic commerce to community detection in social networks. In many of these applications, the underlying context is better modelled as a weighted hypergraph that keeps evolving with time. This motivates the problem of maintaining the densest subhypergraph of a weighted hypergraph in a dynamic setting, where the input keeps changing via a sequence of updates (hyperedge insertions/deletions). Previously, the only known algorithm for this problem was due to Hu et al. [HWC17]. This algorithm worked only on unweighted hypergraphs, and had an approximation ratio of (1

Low-income housing system in Mexico City.

Thesis. 1976. Ph.D.--Massachusetts Institute of Technology. Dept. of Urban Studies and Planning.Microfiche copy available in Archives and Rotch.Bibliography: leaves 491-501.Ph.D

Is Smart Growth Smart for Low-Income Households: A Study of the Impact of Four Smart Growth Principles on the Supply of Affordable Housing

This research tests the relationship between each of four smart growth principles and the supply of affordable housing for low-income households. The four principles are higher residential density, a variety of housing options, mixed land use, and the preservation of open space. The relationships are tested at the neighborhood level in two different types of metropolitan regions, those with an urban containment policy to combat sprawl and those without. Four regions were chosen to represent two pairs. Each pair consisted of two regions which had similar urban containment policies at one point in time and different policies at a second point. By comparing regression analyses from these two points in time, the research design can detect the influence of urban containment on the relationships among the specific smart growth principles and the supply of affordable units. The first pair of regions is of Portland and Seattle. Urban growth boundaries were present in the Portland region in 1990, but not in the Seattle region. Such boundaries were present in both regions in 2000. The second pair consists of the regions of Baltimore and Philadelphia. Neither region had urban containment in 1990, but priority funding areas were established throughout the Baltimore region by 2000.The research provides evidence for the following conclusions. First, a variety of housing options, specifically the availability of multi-unit structures, is associated with a greater supply of affordable rental units. Second, greater residential density in general is typically associated with a greater supply of affordable rental units. Third, a variety of housing options better explains the variation in the supply of affordable units than a general measure of density. Fourth, urban containment policies do not influence the relationships between the smart growth principles and the supply of affordable housing. A policy implication of these conclusions is that growth management mandates to increase residential density should also specify the type of housing developed if growth management is to have positive consequences for the supply of affordable units

Framing the Family-House Stock in Contemporary Italy Construction, Situations, Evolution Patterns

Family houses are the principal material of the dispersed settlements that have marked the Italian landscape since the 1970s. The presentation provides an overview on the main generative processes that shaped the existing stock of family houses according to the social and economic contexts in which it grew; a focus on the recurring “conditions” in which we found such stock today; an assessment of the demographic and social evolutions that are affecting family houses and that could inspire some policy considerations

The Effectiveness of European Regulatory Governance : The Case of Pharmaceutical Regulation

While the regulation of healthcare in EU member states has remained largely unaffected by EU influence, the opposite is true for the regulation of pharmaceutical safety. Since the thalidomide crisis, supranational influence has constantly and continuously expanded in this regulatory field. The emergence of European pharmaceutical policy raises two main questions adressed in the present study. The first question relates to the delegation of regulatory competencies in the pharmaceutical sector. Pharmaceuticals are important for the maintenance of public health but at the same time represent a consumption risk. Therefore, the need for public intervention arises. Governments play an important role in the financing of pharmaceuticals and the protection of their citizens from potentially harmful products. The protection of its citizens is one of the key tasks of the state. The evident delegation of regulatory powers to the European level in the field of risk regulation thus seems to be at odds with the member states’ need to legitimize their activities. The present study thus tries to develop an explanation for the delegation of regulatory competencies in the area of pharmaceutical regulation and in the field of risk regulation in more general terms. The second part of the study analyses in how far the Europeanization of pharmaceutical regulation has impacted on the quality of regulation and its effectiveness, depicting the degree of regulatory goal attainment. The study covers the development of pharmaceutical regulation from the late 1950s until the end of 2008