Yung-Chuan Lee

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We propose a new approach towards Particle Swarm Optimization named Agent-based PSO. The swarm is elevated to the status of a multi-agent system by giving the particles more autonomy, an asynchronous execution, and superior learning capabilities. The problem space is modeled as an environment which forms clusters ofpoints that are known to be non-optimal(More)
A three-phase voltage-source inverter for a power quality compensator under the unbalanced mains and nonlinear loads is proposed to provide balanced three-phase source current and improve input power factor. The proposed converter is based on the conventional three-phase voltage-source inverter with three additional ac power switches to achieve three-level(More)
The purpose of this paper is to introduce an innovative framework for implementation of ambient intelligence (AmI) environments. Compared to the existing state-of-the-art approaches, this framework creates a more decentralized and distributed AmI environment. In addition, the proposed approach is not limited to one specific domain, unlike many others. The(More)
In this paper, we propose a new failure-recovery model for workflow management systems (WfMSs). This model is supported with a new language, called the workflow failure-handling (WfFH) language, which allows the workflow designer to write programs so that s/he can use data-flow analysis technology to guide the failure recovery in workflow execution. With(More)
Recent advances of computing and networking technology have shifted computing convention from stationary to mobile. A forecast conducted by Gartner indicates that global mobile handset sales will increase exponentially in 2008 by 10% from 1.3 billion units in 2007 [13]. Furthermore, the popularity of wireless networking topology including both Wi-Fi access(More)
Covert channel attacks utilize shared resources to indirectly transmit sensitive information to unauthorized parties. Current security mechanisms such as SELinux rely on tagging the filesystem with access control properties. However, such mechanisms do not provide strong protection against information laundering via covert channels. Colored Linux [20], an(More)
Without the security assurance from the underlining operating system, software agents and agencies are constantly under security threats through the operating system. Although the security issues between software agents and agencies have been studied intensively, any formulated counter-measurement of these issues are subject to attacks that are able to(More)
Pi-Calculus is a formal method for describing and analyzing the behavior of large distributed and concurrent systems. Pi-calculus offers a conceptual framework for describing and analyzing the concurrent systems whose configuration may change during the computation. With all the advantages that pi-calculus offers, it does not provide any methods for(More)