The field of Semantic Web services marries the technology of delivering services over the Web with the Semantic Web. This brings up a variety of issues, which range from service-specific and domain ontologies to service discovery, service choreography (i.e., specification of how autonomous client agents interact with services), automated contracting for services, service enactment, execution monitoring, and others. A number of past and ongoing projects proposed solutions to some of these problems. These include OWL-S,SWSL,WSMO,and WSCDL.WSMO is one of the more comprehensive approaches to Semantic Web Services, as it covers virtually all of the aforementioned areas. In this paper, we focus on one particular aspect of WSMO—its support for service choreography,which is based on the formalism of Abstract State Machines (ASMs) [3].
Although ASMs have been used to design and verify software in the past, this
formalism is too general and leaves Web service designers to their own sevices.To the best of our knowledge, there has been little work to help guide Web service designers through the process of actual building of ASM-based choreographies. Our first contribution is to show that control flow graphs, which are commonly used to design workflows (and thus can be used as visual design tools for choreographies), have a modular translation into ASMs and can be used to specify WSMO choreography interfaces.
Corporate managers in the US and Europe claim that maintaining "financial flexibility" is the primary objective of their firms' financial policies (see Graham and Harvey (2001) and Banceland Mittoo (2002)). Their stated policies are consistent with the goal of ensuring funding for present and future investment undertakings in a world where financing frictions force fir ms to pas sup profitable opportunities. In spite of those assertions, empirical work on capital structure often ignores much of the interplay between corporate investment and financing decisions.
During the last decade, regulatory changes and technological innovations have allowed banks to increase their geographical reach. While these changes make banks able to better diversify their loan portfolio, they can also affect lending relationships since especially for opaque borrowers banks collect information through a face-to-face interaction (Petersen and Rajan, 2002).
Since Diamond’s (1984) seminal paper, it has been argued that financial intermediaries arise in order to overcome the consequences of informational asymmetries between lenders and borrowers. However, banks differ in their ability to deal with opaque borrowers.
