Derek L. Nazareth

Measuring Reliability of Applications Composed of Web Services

Web services represent an alternative basis for the rapid development of application systems. Much of the research on composition and orchestration of Web services centers around functional sufficiency and performance. Non-functional characteristics like reliability and security play an important role in the selection of Web services by system architects. This paper provides a basis for measuring reliability of an application system that is assembled using Web services. It outlines criteria for measuring reliability for individual tasks, specifies combining functions for differently configured tasks, and applies these techniques to a problem which contains various sizes of business processes to demonstrate the efficacy of the approach

Information Technology Skill Management: A Systems Dynamics Approach

Managing information technology (IT) human resources and skills presents a challenging task for executives. With IT skill shortages projected to reach unprecedented levels, making the right choices for IT human resource management is increasingly considered imperative for shaping a firms competitive advantage. The complexity associated with the fluctuating demand for IT skills, coupled with dynamic and innovative approaches to short-term and long-term staffing, as well as the inevitable delays in skill acquisition, makes this a challenging task. This research attempts to examine the impact of potential staffing strategies under various conditions, and provide guidance for staffing decisions, using a systems dynamics approach. The model and accompanying simulation can serve as a practical decision support system for IT human resource decision makers.

Visualizing Attribute Interdependencies Using Mutual Information, Hierarchical Clustering, Multidimensional Scaling, and Self-organizing Maps

Data pre-processing tends to be the most critical and time-consuming step during data mining processes. Understanding the inter dependencies among the attributes is especially important for attribute selection and model structure design. Correlation measures, such as Pearson correlation coefficient, have been typically used to measure attribute dependencies. Correlation is useful for capturing linear dependency among quantitative attributes, and is invariant under linear transformations of the variables only. More recently, mutual information has been used to measure interdependencies among attributes measured in continuous scale. Mutual information is applicable to quantitative and categorical variables, captures any type of functional dependency between variables, and is invariant under one-to-one transformations. In this paper, we employ mutual information as a unified measure of interdependencies among attributes, by extending it to accommodate attributes measured in continuous and categorical scales. We further visualize the attribute interdependencies using a host of techniques, including hierarchical clustering, multidimensional scaling, and self-organizing maps. The use of mutual information permits identification of some salient interdependencies between attributes. We demonstrate the utility of the proposed methodology using real data mining applications

Derivation of traffic volumes for effective distribution of object-oriented applications

The paper specifies a procedure to derive traffic volume information for distribution of object-oriented applications. An accurate picture of traffic volumes between application components and sites, and among application components is crucial for effective design of any distributed application. The procedure represents a considerable improvement over the traditional practice of requiring application designers to provide best guess estimates of traffic volumes among application components. This approach exploits knowledge about the way in which objects are to be fragmented to compile the required traffic volumes. The knowledge utilized includes information on attribute values and messaging needed for transaction scenarios. Estimates of traffic volume generated by this procedure are of immense help to the application designer during the allocation phase of object-oriented system distribution. The procedure is amenable to automation, and has been successfully applied to a real-world application.

Direct manipulation support for flexible manufacturing systems using an object-oriented model

Though interest in flexible manufacturing systems (FMS) has demonstrated a spiraling trend, much of the research in the area tends to be fragmentary, in part due to the complexity of problems in the domain, and the multiplicity of solution strategies employed to address them. This paper proposes a comprehensive model for FMS using an object-oriented representation, that permits addressing of individual problems via heuristic solution procedures. The solution process is enhanced through the use of a direct manipulation interface that permits the designer to intervene and control the functioning of the system with minimal syntactic knowledge.<<ETX>>