9,281 research outputs found
Towards a Unified Framework for Declarative Structured Communications
We present a unified framework for the declarative analysis of structured
communications. By relying on a (timed) concurrent constraint programming
language, we show that in addition to the usual operational techniques from
process calculi, the analysis of structured communications can elegantly
exploit logic-based reasoning techniques. We introduce a declarative
interpretation of the language for structured communications proposed by Honda,
Vasconcelos, and Kubo. Distinguishing features of our approach are: the
possibility of including partial information (constraints) in the session
model; the use of explicit time for reasoning about session duration and
expiration; a tight correspondence with logic, which formally relates session
execution and linear-time temporal logic formulas
Data integration through service-based mediation for web-enabled information systems
The Web and its underlying platform technologies have often been used to integrate existing software and information systems. Traditional techniques for data representation and transformations between documents are not sufficient to support a flexible and maintainable data integration solution that meets the requirements of modern complex Web-enabled software and information systems. The difficulty
arises from the high degree of complexity of data structures, for example in business and technology applications, and from the constant change of data and its
representation. In the Web context, where the Web platform is used to integrate different organisations or software systems, additionally the problem of heterogeneity
arises. We introduce a specific data integration solution for Web applications such as Web-enabled information systems. Our contribution is an integration technology
framework for Web-enabled information systems comprising, firstly, a data integration technique based on the declarative specification of transformation rules and the construction of connectors that handle the integration and, secondly, a mediator architecture based on information services and the constructed connectors to handle the integration process
Mediated data integration and transformation for web service-based software architectures
Service-oriented architecture using XML-based web services has been widely accepted by many organisations as the standard infrastructure to integrate heterogeneous and autonomous data sources. As a result, many Web service providers are built up on top of the data sources to share the data by supporting provided and required interfaces and methods of data access in a unified manner. In the context of data integration, problems arise when Web services are assembled to deliver an integrated view of data, adaptable to the specific needs of individual clients and providers. Traditional approaches of data integration and transformation are not suitable to automate the construction of connectors dedicated to connect selected Web services to render integrated and tailored views of data. We propose a declarative approach that addresses the oftenneglected data integration and adaptivity aspects of serviceoriented
architecture
Higher-level Knowledge, Rational and Social Levels Constraints of the Common Model of the Mind
In his famous 1982 paper, Allen Newell [22, 23] introduced the notion of knowledge level to
indicate a level of analysis, and prediction, of the rational behavior of a cognitive articial agent.
This analysis concerns the investigation about the availability of the agent knowledge, in order
to pursue its own goals, and is based on the so-called Rationality Principle (an assumption
according to which "an agent will use the knowledge it has of its environment to achieve its
goals" [22, p. 17]. By using the Newell's own words: "To treat a system at the knowledge level
is to treat it as having some knowledge, some goals, and believing it will do whatever is within
its power to attain its goals, in so far as its knowledge indicates" [22, p. 13].
In the last decades, the importance of the knowledge level has been historically and system-
atically downsized by the research area in cognitive architectures (CAs), whose interests have
been mainly focused on the analysis and the development of mechanisms and the processes
governing human and (articial) cognition. The knowledge level in CAs, however, represents
a crucial level of analysis for the development of such articial general systems and therefore
deserves greater research attention [17]. In the following, we will discuss areas of broad agree-
ment and outline the main problematic aspects that should be faced within a Common Model
of Cognition [12]. Such aspects, departing from an analysis at the knowledge level, also clearly
impact both lower (e.g. representational) and higher (e.g. social) levels
Models for Trustworthy Service and Process Oriented Systems
Service and process-oriented systems promise to provide more effective business and work processes and more flexible and adaptable enterprise IT systems. However, the technologies and standards are still young and unstable, making research in their theoretical foundations increasingly important.
Our studies focus on two dichotomies: the global/local views of service interactions, and their imperative/declarative specification.
A global view of service interactions describes a process as a protocol for interactions, as e.g. an UML sequence diagram or a WS-CDL choreography. A local view describes the system as a set of processes, e.g. specified as a mipi-calculus or WS-BPEL process, implementing each participant in the process. While the global view is what is usually provided as specification, the local view is a necessary step towards a distributed implementation.
If processes are defined imperatively, the control flow is defined explicitly, e.g. as a sequence or flow graph of interactions/commands. In a declarative approach processes are described as a collection of conditions they should fulfill in order to be considered correct. The two approaches have evolved rather independently from each other. Our thesis is that we can provide a theoretical framework based on typed concurrent process and concurrent constraint calculi for the specification, analysis and verification of service and process oriented system designs which bridges the global and local view and combines the imperative and declarative specification approaches, and can be employed to increase the trust in the developed systems.
This article describes our main motivations, results and future research directions
The Knowledge Level in Cognitive Architectures: Current Limitations and Possible Developments
In this paper we identify and characterize an analysis of two problematic aspects affecting the representational level of cognitive architectures (CAs), namely: the limited size and the homogeneous typology of the encoded and processed knowledge.
We argue that such aspects may constitute not only a technological problem that, in our opinion, should be addressed in order to build articial agents able to exhibit intelligent behaviours in general scenarios, but also an epistemological one, since they limit the plausibility of the comparison of the CAs' knowledge representation and processing mechanisms with those executed by humans in their everyday activities. In the final part of the paper further directions of research will be explored, trying to address current limitations and
future challenges
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