Preventing Location-Based Identity Inference in Anonymous Spatial Queries

The increasing trend of embedding positioning capabilities (for example, GPS) in mobile devices facilitates the widespread use of Location-Based Services. For such applications to succeed, privacy and confidentiality are essential. Existing privacy-enhancing techniques rely on encryption to safeguard communication channels, and on pseudonyms to protect user identities. Nevertheless, the query contents may disclose the physical location of the user. In this paper, we present a framework for preventing location-based identity inference of users who issue spatial queries to Location-Based Services. We propose transformations based on the well-established K-anonymity concept to compute exact answers for range and nearest neighbor search, without revealing the query source. Our methods optimize the entire process of anonymizing the requests and processing the transformed spatial queries. Extensive experimental studies suggest that the proposed techniques are applicable to real-life scenarios with numerous mobile users

A Theoretical Foundation for Bilateral Matching Mechanisms

This work introduces a rigorous set-theoretic foundation of bilateral matching mechanisms and studies their properties in a systematic manner. By providing a unified framework to study ilateral matching mechanisms, we formalize how different spatial/informational constraints can be implemented via a careful selection of matching mechanisms. In particular, this paper explains why and how various matching mechanisms generate different degrees of information isolation in the economyspatial interactions, matching, information frictions

A Typology of Virtual Teams: Implications for Effective Leadership

As the nature of work in today\u27s organizations becomes more complex, dynamic, and global, there has been an increasing emphasis on far-flung, distributed, virtual teams as organizing units of work. Despite their growing prevalence, relatively little is known about this new form of work unit. The purpose of this paper is to present a theoretical framework to focus research toward understanding virtual teams and, in particular, to identify implications for effective leadership. Specifically, we focus on delineating the dimensions of a typology to characterize different types of virtual teams. First, we distinguish virtual teams from conventional teams to identify where current knowledge applies and new research needs to be developed. Second, we distinguish among different types of virtual teams, considering the critical role of task complexity in determining the underlying characteristics of virtual teams and leadership challenges the different types entail. Propositions addressing leadership implications for the effective management of virtual teams are proposed and discussed

Being together, worlds apart: a virtual-worldly phenomenology

Previous work in Game Studies has centered on several loci of investigation in seeking to understand virtual gameworlds. First, researchers have scrutinized the concept of the virtual world itself and how it relates to the idea of “the magic circle”. Second, the field has outlined various forms of experienced “presence”. Third, scholarship has noted that the boundaries between the world of everyday life and virtual worlds are porous, and that this fosters a multiplicity of identities as players identify both with themselves-offline and themselves-in-game. Despite widespread agreement that these topics are targets for research, so far those working on these topics do not have mutually agreed-upon framework. Here we draw upon the work of Alfred Schutz to take up this call. We provide a phenomenological framework which can be used to describe the phenomena of interest to Game Studies, as well as open new avenues of inquiry, in a way acceptable and useful to all. This helps to distinguish the core of the field from the supplemental theoretical and critical commitments which characterize diverse approaches within the field

Group size effect on cooperation in one-shot social dilemmas II. Curvilinear effect

In a world in which many pressing global issues require large scale cooperation, understanding the group size effect on cooperative behavior is a topic of central importance. Yet, the nature of this effect remains largely unknown, with lab experiments insisting that it is either positive or negative or null, and field experiments suggesting that it is instead curvilinear. Here we shed light on this apparent contradiction by considering a novel class of public goods games inspired to the realistic scenario in which the natural output limits of the public good imply that the benefit of cooperation increases fast for early contributions and then decelerates. We report on a large lab experiment providing evidence that, in this case, group size has a curvilinear effect on cooperation, according to which intermediate-size groups cooperate more than smaller groups and more than larger groups. In doing so, our findings help fill the gap between lab experiments and field experiments and suggest concrete ways to promote large scale cooperation among people.Comment: Forthcoming in PLoS ON

A Survey of Models of Network Formation: Stability and Efficiency

I survey the recent literature on the formation of networks. I provide definitions of network games, a number of examples of models from the literature, and discuss some of what is known about the (in)compatibility of overall societal welfare with individual incentives to form and sever links

Social Software, Groups, and Governance

Formal groups play an important role in the law. Informal groups largely lie outside it. Should the law be more attentive to informal groups? The paper argues that this and related questions are appearing more frequently as a number of computer technologies, which I collect under the heading social software, increase the salience of groups. In turn, that salience raises important questions about both the significance and the benefits of informal groups. The paper suggests that there may be important social benefits associated with informal groups, and that the law should move towards a framework for encouraging and recognizing them. Such a framework may be organized along three dimensions by which groups arise and sustain themselves: regulating places, things, and stories