The concept of trust in multi-agent systems (MASs) has received significant attention in recent years, and a number of approaches have been proposed to enable agents to form, maintain and use trust relationships in their dealings with others.  However, current approaches do not adequately address <i>highly dynamic </i>multi-agent systems, where the population and structure changes frequently.  For example, agents may frequently join and leave, and ad-hoc structures may form in response to emerging situations. In these highly unstable environments, trust can be difficult or impossible to build with existing techniques.  Trust matters most when risk is involved, but in situations of extreme uncertainty, the risk may be too great to permit any interactions, resulting in a breakdown of the system. In this thesis, we propose a general approach for trust evaluation and decision-making in highly dynamic multi-agent systems.  First, we present a model of <i>stereotypes, </i>which allows agents to build tentative trust relationships with others on the basis of visible features.  We show that this approach can help agents to form trust relationships, despite a high degree of social dynamicity.  We present a method of selecting providers of trust evidence, when those providers may be stereotypically biased. Secondly, we present a trust decision-making model which employs <i>controls</i>, as well as trust evaluations and stereotypes, in order to facilitate initial interactions when trust is low or absent, and bootstrap dynamic societies.  We show that control can be used initially to enable interactions.  As trust builds, control can be reduced.  Our approach is general and applicable to existing models of trust in MASs.  We evaluate our model within a simulated multi-agent environment characterised by high degrees of dynamicity and structural change.

Today’s contemporary challenges of educating students place responsibility on school principals that may be unmatched by any other generation. Principals in their early years of the portfolio face an even greater task as they become comfortable with the portfolio and the school community which they lead. Drawing from the leadership literature that emphasized the importance of trust for effective school leadership and improvement, this qualitative study examines the formal and informal leadership practices of seven principals/ headmasters with less than eight years of experience in private high schools in Ontario. The study focuses on the practices that these leaders identify as being crucial to building trust. Their responses reveal that trust building includes personal and professional honesty, transparency and clear communication and a sharing of decision-making powers which all help to minimize the micropolitics that arise in a school, engenders better relationships with faculty members, increases capacity of faculty members more effectively, and ultimately provides support for the principal and decreases personal stress. This study contributes to the Canadian literature on school leadership and the literature on private school leadership and concludes with recommendations for both research and practice.

The Web has become an open decentralized global information / knowledge repository, a platform for distributed computing and global electronic markets, where people are confronted with information of unknown sources, and need to interact with “strangers”. This makes trust and the validity of information in cyberspace arise as crucial issues. This thesis proposes knowledge provenance (KP) as a formal approach to determining the origin and validity of information / knowledge on the Web, by means of modeling and maintaining the information sources, information dependencies, and trust structures. We conceptualize and axiomatize KP ontology including static KP and dynamic KP. The proposed KP ontology, provides a formal representation of linking trust in information creators and belief in the information created; lays a foundation for further study of knowledge provenance; provides logical systems for provenance reasoning by machines. The web ontology of KP can be used to annotate web information; and KP reasoner can be used as a tool to trace the origin and to determine the validity of Web information. Since knowledge provenance is based on trust in information sources, this thesis also proposes a logical theory of trust in epistemic logic and situation calculus. In particular, we formally define the semantics of trust; from it, we identify two types of trust: trust in belief and trust in performance; reveal and prove that trust in belief is transitive; trust in performance is not, but by trust in belief, trust in performance can propagate in social networks; by using situation calculus in trust formalization, the context of trust is formally represented by reified fluents; we also propose a distributed logical model for trust reasoning using social networks, by which each agent’s private data about trust relationships can be protected. This study provides a formal theoretical analysis on the transitivity of trust, which supports trust propagation in social networks. This study of trust supports not only knowledge provenance but also the general trust modeling in cyberspace.

Today’s contemporary challenges of educating students place responsibility on school principals that may be unmatched by any other generation. Principals in their early years of the portfolio face an even greater task as they become comfortable with the portfolio and the school community which they lead. Drawing from the leadership literature that emphasized the importance of trust for effective school leadership and improvement, this qualitative study examines the formal and informal leadership practices of seven principals/ headmasters with less than eight years of experience in private high schools in Ontario. The study focuses on the practices that these leaders identify as being crucial to building trust. Their responses reveal that trust building includes personal and professional honesty, transparency and clear communication and a sharing of decision-making powers which all help to minimize the micropolitics that arise in a school, engenders better relationships with faculty members, increases capacity of faculty members more effectively, and ultimately provides support for the principal and decreases personal stress. This study contributes to the Canadian literature on school leadership and the literature on private school leadership and concludes with recommendations for both research and practice.

Low levels of productivity and recent evolutions in technology and practices are pushing the construction industry to collaborate on a higher level. A key component of effective collaboration is trust. Research also suggests that increased trust levels can lead to improved productivity in team performance. Trust appears to be valued by industry practitioners at the executive level but it also appears that active management of trust is minimal. With Design Science Research methodology as a framework, this project uses a mixed methods approach to develop and test a tool designed to assist in the management of trust levels between construction project participants. This project lays the groundwork for additional research into trust-building in construction by testing whether or not trust can be actively built and managed by rigorous analysis of current and upcoming relationships. In addition to supporting data from case studies, this was accomplished by introducing specific trust-building techniques into student group interactions and comparing changes in interpersonal trust levels to a control group of students. Results from the case studies and student experiment show some support for the idea that interpersonal trust levels, as perceived by the person making the attempts to build trust within the group, can be increased through use of a tool such as the one developed. Further testing and development is needed prior to wider industry application.

Service-based software can be exploited by potentially untrustworthy service requestors while providing services. Given that, it is important to identify, analyze the trust relationships between service providers and requestors, and incorporate them into the service-based software. Treating trust as a nonfunctional requirement (NFR) during software development and monitoring allows clarifying these relationships and measuring the trustworthiness of service requestors. This analysis is facilitated by incorporating trust scenarios and trust models into the software. A trust scenario describes a trust relationship between interested parties based on a specific context. A trust model provides trust equations to measure the trustworthiness of service requestors based on the analysis of service-based interactions. Although much research has been devoted to monitor service quality, to date, no approach has been proposed to develop and automatically monitor service providing software from trust perspectives. In this thesis, we propose a trust-aware service-based software development framework which utilizes our proposed Unified Modeling Language (UML) extension called UMLtrust (UML for trust scenarios)to specify the trust scenarios of a service provider and incorporates our developed trust model called CAT (Context-Aware Trust) into the software to calculate the trustworthiness of service requestors. The trust scenarios are converted to trust rules to monitor service-based interactions. A service requestor is penalized for the violation of a trust rule and rewarded when no rule is violated. The trustworthiness of the requestor is then calculated (using the equations of CAT) based on the current request, outcomes of previous requests, and recommendations from other service providers. A trust-based service granting algorithm is presented to decide whether a service requestor should be granted the requested service. A trust monitoring architecture is presented which is assumed to reside in each service provider. The monitor uses trust rules from UMLtrust specifications and trust equations from CAT to analyze service-based interactions. The incorporation of the monitor into a provider makes it trust-aware. A trust monitoring algorithm is provided to analyze interactions and make decisions at run-time. A prototype of a file sharing service-based grid is implemented to evaluate the applicability of our framework that confirms the effectiveness of the framework. / Thesis (Master, Electrical & Computer Engineering) -- Queen's University, 2008-02-11 15:57:22.003 / Natural Sciences and Engineering Research Council (NSERC)

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This dissertation explores the relevance of corporate governance in the nonprofit sector in South Africa, and asks the question "How can the application of current formal governance measures lead to positive change at The Valley Trust? ". Significantly, in South Africa it has been a time of transformation, with the emergence of world-class strategies to enhance governance in both the public and the private sectors. Are the principles of good governance are applicable too, to non-profit organisations? South Africa has evidence of relevant documentation both in the public and private sectors. In the private sector the King 2002 report strengthened the original King report which in turn was guided by the Cadbury report on corporate governance in the North. The King 2002 report on corporate governance is considered to be world class and emphasises risk management, leadership, direction, control and disclosure. The Public Finance Management Act, together with the subsequent Treasury Regulations and the local government's Municipal Finance Management Act, spell out the way forward for governance in the public sector with the emphasis on effectiveness, efficiency and economy as assessment criteria in terms of revenue, expenditure, assets and liabilities (REAL) with special reference to risk management and accountability. In terms of enhancing sustainability and good stewardship, The Valley Trust, a non-profit organisation working in Primary Health Care and Development in Southern Africa, has the opportunity to use the resources available, and to apply the current thinking and principles of good governance. / Thesis (M.Com.)-University of KwaZulu-Natal, 2005.

When it comes to improving tax revenues in developing countries, we do not have a clear understanding of whether it is more important to have democracy or state effectiveness. Two theories have prevailed in the literature; one is to focus on building strong states that can have financial autonomy, the other is to promote democracy with the assumption that democracy brings about economic growth. Yet, for over four decades, developing countries’ tax to GDP ratio is still desperately low. On average, developing countries ‘tax to the GDP ratio is less that half that of the OCDE countries. This article contends that greater taxation outcomes result from the synergistic combination between democracy and state effectiveness. Empirical evidence from a time-series-cross-sectional dataset covering up to 120 countries during the 2003-2012 time period supports the conclusion that the two attributes working together increase tax revenue by 16% because they force political leaders to focus on citizens by improving their political participation (democracy) and by meeting voters’ basic needs (performance).

Web-based social networks have become one of the most popular applications on the Internet in recent years. However, most of the social networks rely on some simplistic trust models to manage trust information of the users, which can cause problems ranging from unsatisfied user experience to exposure to malicious users. This thesis proposes a gravity-based trust model to enhance the aggregation of personal trust information into a subjective reputation system. This new model maps all users on the social network into n-dimensional Euclidean spaces based on their direct trust information, and creates a trust social neighborhood for each user. The reputation of a target user is determined by applying gravity model to the information from both target's and observer's trust social neighborhood. A prototype of this trust model is implemented in order to evaluate the effects of varying different parameters of the gravity-based trust model.