BACKGROUND To examine the association between individual-level social capital and physical activity. METHODOLOGY/PRINCIPAL FINDINGS In February 2009, data were collected in a population-based cross-sectional survey in Okayama city, Japan. A cluster-sampling approach was used to randomly select 4,000 residents from 20 school districts. A total of 2260 questionnaires were returned (response rat...

In this paper, we present a class of trust region algorithms for minimization problems within convex feasible regions, in which the structure of the problem is explicitly used in the deenition of the trust region. This development is intended to reeect the possibility that some parts of the problem may be more accurately modelled than others, a common occurrence in large-scale nonlinear applica...

In order to better model agent-agent interaction, a robust model for trust is necessary. Many computational trust models have been created in the past, but during the course of research, I’ve found none that model every facet of trust appropriately. In order to rectify this, I’ve devised a model based off of prior work in the field, and some ideas gleaned from sociology and neurobiology. The co...

Trust is an important tool in human life, as it enables people to cope with the uncertainty caused by the free will of others. Uncertainty and uncontrollability are also issues in computer-assisted collaboration and electronic commerce in particular. A computational model of trust and its implementation can alleviate this problem. This survey is directed to an audience wishing to familiarize th...

Virtual communities (VCs) are socio-technical systems wherein distributed individuals (human and/or artificial) are grouped together around common objectives and goals [10, 6]. In such systems, participants are massively collaborating with each others by sharing their private resources and knowledge. A collaboration always bears the risk that one partner exhibits uncooperative or malicious beha...

W investigate the epistemology of trust in social networks. We posit trust as a special epistemic state that depends on actors’ beliefs about each others’ beliefs as well as about states of the world. It offers new ideas and tools for representing the core elements of trust both within dyads and larger groups and presents an approach that makes trust measurable in a noncircular and predictive, ...

In order to better model agent-agent interaction, a robust model for trust is necessary. Many computational trust models have been created in the past, but during the course of research, I’ve found none that model every facet of trust appropriately. In order to rectify this, I’ve devised a model based off of prior work in the field, and some ideas gleaned from sociology and neurobiology. The co...

The ability of 3- to 5-year-old children to reason about trust in relation to the honest behavior of others was examined across five studies (total N=496). Results showed that although 4-year-olds differentiated between honest and dishonest sources in their trust judgments, only 5-year-olds demonstrated a clear capacity to differentiate between honesty and a trust-irrelevant dimension (i.e., cl...

Title of dissertation: ROBUST NETWORK TRUST ESTABLISHMENT FOR COLLABORATIVE APPLICATIONS AND PROTOCOLS Georgios E. Theodorakopoulos Doctor of Philosophy, 2007 Dissertation directed by: Professor John S. Baras Department of Electrical and Computer Engineering In networks without centralized control (e.g. ad-hoc or peer-to-peer networks) the users cannot always be assumed to follow the protocol t...

Regulating water resources is a critically important yet increasingly complex component of the interaction between ecology and society. Many argue that effective water regulation relies heavily upon the compliance of water users. The relevant literature suggests that, rather than relying on external motivators for individual compliance, e.g., punishments and rewards, it is preferable to focus o...