We propose a coarse-grained simulation method which takes the effect of memory access contention into account. The method can be used for the evaluation of the execution time of an application program during the system architecture design in an early phase of development. In this phase, information about memory access timings is usually not available. Our method uses a statistical approximation of the memory access timings to estimate their influences on the execution time. We report a preliminary verification of our simulation method by comparing it with an experimental result from an image processing application on a dual-core PC. We find an error of the order of 3 percents on the execution time.

This paper describes a system-level modeling method in UML for performance evaluation of embedded systems. The core technology of this modeling method is reverse modeling based on dynamic analysis. A case study of real MFPs (multifunction peripherals/printers) is presented in this paper to evaluate the modeling method.

The service-oriented architecture (SOA) makes application development easier, because applications can be built from existing services with a bottom-up methodology. However, it is difficult to determine if a desired new service can be built from existing services. Not only the functional consistency of the existing services, but also the consistency of their non-functional (such as security) aspects must be verified. Message protection is an aspect of security. Every service needs an appropriate security policy defining the protection of messages exchanged between the parties to the service. Because of the intricacy of the Web services security policy language, it is difficult to verify the consistency of the security policies. We are developing a method to verify the consistency of security policies by abstracting them. Each security policy is abstracted, and then attached as a security type to the corresponding service in the application model. The security type denotes a security level for message protection. The security developer defines the possible abstraction methods. In this paper, we define the constraint of abstraction methods based on the semantics of the policy language. And also we state verifying the consistency of security types by using information flow analysis.

Automated verification for client-side programs of DHTML applications has become necessary. This is because DHTML applications are increasingly complicated in order to enhance the functionality and usability of dynamic Web content. We are therefore motivated to create a tool for automatically verifying a JavaScript program of a DHTML application against a specification describing the page flows. The verification is based on a type inference technique focusing on DOM updates

Abstract Aglets, a framework and runtime platform for mobile agents developed by the IBM Tokyo Research Laboratory, is an advanced system of mobile agents written in Java, and is already used in some commercial applications. Using mobile agent technologies provides potential benefits to applications, but they also pose security threats to those applications. These threats not only come as malicious agents, but also in the form of malicious hosts. In this paper we introduce security features against these threats. Access control and message protection can prevent attacks by malicious agents. Server authentication allows agents to avoid movement to malicious hosts and blocks suspicious agents coming from malicious hosts. Copyright © 2002 John Wiley & Sons, Ltd.