Browsing by Author "Wang, FH"

Now showing 1 - 7 of 7

A cooperative framework for inter-organizational workflow system
(2003)
Yan, SB
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Wang, FH
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資訊工程學系
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Department of Computer Science
Workflow management systems (WfMSs) are accepted worldwide due to their capability to model and control business processes. With WfMS, enterprises can improve work efficiency and react to the emergent situation quickly. However, most WfMSs adopt the centralized architecture in an organization so that they usually lack of a cooperative communication mechanism across different organizations. In this paper, we propose a cooperative framework for inter-organizational workflow systems. The framework consists of an inter-workflow meta-model, CA-PLAN (Cooperative Agentflow Process LANguage), and a prototype system based on Agentflow, a system developed in our laboratory. The cooperation mechanism between WfMSs in CA-PLAN is modeled as a Remote Call Process (RCP) paradigm. A Process Service is a mechanism that defines a process to participate in an inter-organizational process among different WfMSs and specifies the associated arguments in and out. A Remote Process is a proxy mechanism that refers to a process service on another WfMS. RCP provides the mechanism by which the process service and the remote process communicate and pass information back and forth and process monitor mechanism. The mechanism, also allowing dynamic changes and reconfiguration, can adapt dynamic and competitive business environment. Through RCP, the cooperative process across organizations becomes simple, faster, and flexible.
A VQ-based robust multi-watermarking algorithm
(2002-07-01)
Huang, HC
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Wang, FH
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Pan, JS
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
New methods for digital image watermarking based on the characteristics of vector quantization (VQ) are proposed. In contrast with conventional watermark embedding algorithms to embed only one watermark at a time into the original source; we present one algorithm to embed multiple watermarks for copyright protection. The embedding and extraction processes are efficient for implementing with conventional VQ techniques; and they can be accomplished in parallel to shorten the processing time. After embedding, embedder would output one watermarked reconstruction image and several secret keys associated with the embedded watermarks. These secret keys are then registered to the third party to preserve the ownership of the original source in order to prevent the attackers from inserting counterfeit watermarks. Simulation results show that under no attacks, the embedded watermarks could be perfectly extracted. If there are some intentional attacks in our simulation, all the watermarks could survive to protect the copyrights. Therefore, we are able to claim the robustness, usefulness, and ease of implementation of our algorithm.
An embedding algorithm for multiple watermarks
(2003-03-01)
Shieh, CS
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Huang, HC
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Wang, FH
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Pan, JS
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電子工程學系及電子研究所
A new algorithm for embedding several watermarks into the same original source is proposed in this paper. Instead of conventional watermark embedding algorithms that embed one watermark in one specific domain, we propose algorithms for embedding multiple watermarks into different compression domains to protect the ownership of the original images. The proposed schemes for embedding and extraction in different domains vary from the existing methods reported in the literature. Simulation results show their robustness for surviving intentional attacks and, hence, their effectiveness in protecting copyrights. They are also easy to implement.
Efficient and robust watermarking algorithm with vector quantisation
(2001-06-21)
Huang, HC
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Wang, FH
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Pan, JS
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
A new method for watermarking based on Vector quantisation is proposed. It is efficient for implementation with conventional techniques, and simulation results show its robustness under a variety of attacks. Tt also represents superiority over eng algorithms.
Genetic watermaking based on transform-domain techniques
(2004-03-01)
Shieh, CS
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Huang, HC
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Wang, FH
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Pan, JS
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電子工程學系及電子研究所
An innovative watermarking scheme based on genetic algorithms (GA) in the transform domain is proposed. It is robust against watermarking attacks, which are commonly employed in the literature. In addition, the watermarked image quality is also considered. In this paper, we employ GA for optimizing both the fundamentally conflicting requirements. Watermarking with GA is easy for implementation. We also examine the effectiveness of our scheme by checking the fitness function in GA, which includes both factors related to robustness and invisibility. Simulation results also show both the robustness under attacks, and the improvement in watermarked image quality with GA. (C) 2003 Pattern Recognition Society. Published by Elsevier Ltd. All rights reserved.
Progressive watermarking techniques with genetic algorithms
(2003)
Huang, HC
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Pan, JS
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Shieh, CS
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Wang, FH
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電子工程學系及電子研究所
An innovative watermarking scheme based on progressive transmission with genetic algorithms (GA) is proposed. We implement the watermarking embedding and extraction system in the discrete cosine transform (DCT) domain, and apply the JPEG spectral selection mode for progressive transmission. By employing GA with a proper fitness function into the watermarking system, both the watermark imperceptibility and watermark robustness requirements are considered and optimized. In addition, the embedded watermark can be partly extracted in the receiver side even when the watermarked image is being transmitted. Simulation results show both the robustness and the effectiveness of progressive transmission under different attacking schemes and different bandwidth variations.
VQ-based gray watermark hiding scheme and genetic index assignment
(2004)
Wang, FH
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Pan, JS
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Jain, L
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Huang, HC
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電子工程學系及電子研究所
A vector quantisation (VQ) based watermarking scheme for hiding the gray watermark is presented. It expands the watermark size, and employs VQ index assignment procedure with genetic algorithm, called genetic index assignment (GIA), for watermarking. The gray watermark is coded by VQ and obtained indices are translated into a binary bitstrearn with a much smaller size. We partition the codebook into two sub-codebooks, and use either one of them based on the value of the bit for embedding. Next, GIA is employed to find better imperceptibility of watermarked image. Experimental results show that the proposed method possesses advantages over other related methods in literature.