A Java implementation of Coordination Rules as ECA Rules

This paper gives an insight in to the design and implementation of the coordination rules as ECA rules. The language specifications of the ECA rules were designed and the corresponding implementation of the same using JAVA as been partially done. The paper also hints about the future work in this area which deals with embedding this code in JXTA, thus enabling to form a P2P layer with JXTA as the back bone

Library for Writing Contracts for Java Programs Using Prolog

Today many large and complex software systems are being developed in Java. Although, software always has bugs, it is very important that these developed systems are more reliable despite these bugs. One way that we can help achieve this is the Design by Contract (DbC) paradigm, which was first introduced by Bertrand Meyer, the creator of Eiffel. The concept of DbC was introduced for software developers so that they can produce more reliable software systems with a little extra cost. Using programming contracts allows developer to specify details such as input conditions and expected output conditions. Doing this makes it easy for the system to assign blame whenever software runs into some erroneous state. Once the blame is assigned it is easier for the developer to detect the cause, so that the appropriate actions can be taken to resolve the issue. My project develops a library in Java that allows developers to write contracts for their Java programs in Prolog. These contracts are then evaluated by the library with the help of a Prolog dictionary which acts as the database. Prolog’s declarative style is a natural fit for writing contracts. With this project, I hope to simplify writing contracts for Java developers. In this paper, I review my implementation. I further discuss some performance tests to show the added overhead

Economic-based Distributed Resource Management and Scheduling for Grid Computing

Computational Grids, emerging as an infrastructure for next generation computing, enable the sharing, selection, and aggregation of geographically distributed resources for solving large-scale problems in science, engineering, and commerce. As the resources in the Grid are heterogeneous and geographically distributed with varying availability and a variety of usage and cost policies for diverse users at different times and, priorities as well as goals that vary with time. The management of resources and application scheduling in such a large and distributed environment is a complex task. This thesis proposes a distributed computational economy as an effective metaphor for the management of resources and application scheduling. It proposes an architectural framework that supports resource trading and quality of services based scheduling. It enables the regulation of supply and demand for resources and provides an incentive for resource owners for participating in the Grid and motives the users to trade-off between the deadline, budget, and the required level of quality of service. The thesis demonstrates the capability of economic-based systems for peer-to-peer distributed computing by developing users' quality-of-service requirements driven scheduling strategies and algorithms. It demonstrates their effectiveness by performing scheduling experiments on the World-Wide Grid for solving parameter sweep applications

Federated Access Management for Collaborative Environments

abstract: Access control has been historically recognized as an effective technique for ensuring that computer systems preserve important security properties. Recently, attribute-based access control (ABAC) has emerged as a new paradigm to provide access mediation by leveraging the concept of attributes: observable properties that become relevant under a certain security context and are exhibited by the entities normally involved in the mediation process, namely, end-users and protected resources. Also recently, independently-run organizations from the private and public sectors have recognized the benefits of engaging in multi-disciplinary research collaborations that involve sharing sensitive proprietary resources such as scientific data, networking capabilities and computation time and have recognized ABAC as the paradigm that suits their needs for restricting the way such resources are to be shared with each other. In such a setting, a robust yet flexible access mediation scheme is crucial to guarantee participants are granted access to such resources in a safe and secure manner. However, no consensus exists either in the literature with respect to a formal model that clearly defines the way the components depicted in ABAC should interact with each other, so that the rigorous study of security properties to be effectively pursued. This dissertation proposes an approach tailored to provide a well-defined and formal definition of ABAC, including a description on how attributes exhibited by different independent organizations are to be leveraged for mediating access to shared resources, by allowing for collaborating parties to engage in federations for the specification, discovery, evaluation and communication of attributes, policies, and access mediation decisions. In addition, a software assurance framework is introduced to support the correct construction of enforcement mechanisms implementing our approach by leveraging validation and verification techniques based on software assertions, namely, design by contract (DBC) and behavioral interface specification languages (BISL). Finally, this dissertation also proposes a distributed trust framework that allows for exchanging recommendations on the perceived reputations of members of our proposed federations, in such a way that the level of trust of previously-unknown participants can be properly assessed for the purposes of access mediation.Dissertation/ThesisDoctoral Dissertation Computer Science 201

A Self-Healing Approach for Object-Oriented Applications

In this paper, we present our approach and architecture for fault diagnosis and self-healing of interpreted objectoriented applications. By combining aspect-oriented programming, program analysis, artificial intelligence, and machine learning techniques, we advocate that our approach can heal a significant number of failures of real interpreted object-oriented applications. 1

A Model Driven Approach for Refactoring Heterogeneous Software Artefacts

Refactoring is the process of transforming a software system to improve its overall structure while preserving its observable behaviour. Refactoring engines are normally used to perform these transformations for efficiency and in order to avoid introducing behavioural changes into the program due to human error. Although these engines do not verify that behaviour is preserved, it is widely accepted that automated transformations are less likely to introduce errors in comparison to manual refactoring. Despite the advantages provided by refactoring engines they fall foul of certain weaknesses. Here we hypothesise that Model Driven Engineering can be used to produce improved refactoring engines that are less vulnerable to those weaknesses. We develop a Domain Specific Transformation Language for defining new composite refactorings from a set of built–in primitives and to script their application. We also develop an interpreter for the language, effectively providing an operational semantics, in the guise of an extensible transformation framework. We evaluate our approach with a case study examining the correlation between actual and predicted measurements of the Coupling Between Objects metric for classes that undergo the extract class refactoring. The results show that our approach is promising