Multi-Decision Policy and Policy Combinator Specifications

Margrave is a specification language and analysis tool for access control policies with semantics based in order-sorted logic. The clear logical roots of Margrave\u27s semantics makes policies specified in the Margrave language both machine analyzable and relatively easy for users to reason about. However, the decision conflict resolution declaration and policy set features of Margrave do not have semantics that are as cleanly rooted in order-sorted logic as Margrave policies and queries are. Additionally, the current semantics of decision conflict resolution declarations and of policy sets do not permit users to take full advantage of the multi-decision capabilities of Margrave policies. The purposes of this thesis are (i) to provide a unified extension to the semantics for policies and policy combination, (ii) to cleanly support decision conflict resolution mechanisms in a general way within those semantics and (iii) to provide insight into the properties of policy combination and decision conflict resolution for multi-decision policies in general. These goals are achieved via the realization that policy combinators may be treated as policies operating within environments extended with the results of the policies to be combined, allowing policy combinators to be defined as if they were policies. The ability to treat policy combinators as policies means that users\u27 current understanding of policies can be easily extended to policy combinators. Additionally, the tools that Margrave has for supporting policies can be leveraged as the Margrave language and analysis tool grow to provide fuller support for policy combination and rule conflict resolution declarations

Towards a Transition System Semantics for Alloy

Alloy is a language for modeling systems using first order logic and relational algebra. In this paper we examine the use of Alloy for creating models of stateful systems, and we explore semantics for Alloy that define transition systems over database instances based on Alloy specifications written in the state-signature idiom. One such semantics is fully adequate for the original semantics of Alloy. We prove an undecidability result concerning the automatic synthesis of programs from specifications under this semantics

Making the Link: Entrepreneurship in Costa Rica

Entrepreneurship is important for the growth of a country\u27s technology business sector. Project Link Investments\u27 mission is to promote entrepreneurship by creating an angel investment network to fund startup companies. In order to develop a set of best practices for Link Investments, we researched case studies of angel investment models and assessed cultural constraints that influence those models by surveying entrepreneurs in Costa Rica. We also used archival data to analyze the possible economic impact of entrepreneurship. The implementation of our recommended practices will help promote the development of an environment of entrepreneurship in Costa Rica