Browsing by Author "Liu, HH"

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A novel access control method using Morton number and prime factorization
(2000-12-01)
Chang, HKC
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Hwang, JJ
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Liu, HH
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資訊管理與財務金融系註：原資管所+財金所
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Department of Information Management and Finance
A novel scheme used for controlling access requests in security information system is proposed. In the proposed method, the system administrator chooses distinct prime numbers representing each atomic access right as well as four large prime numbers for encryption. By setting these representative prime numbers as input parameters, the proposed method applies a one-way function combining the Morton number theory transferring into a single value to derive the encrypted compound privilege (ECP). With ECP, verification of right of access can be achieved easily and secretly. Meanwhile, the proposed scheme provides the following advantages: (I) the verification of right of access can be effectively implemented using the Morton sequence with coordinate transformation; (2) the problem of dynamic access control also can be effectively implemented; (3) integrity and confidentiality while controlling system resources can be ensured; (4) the proposed method can decrease the redundancy of the access matrix in some specific circumstances. (C) 2000 Elsevier Science Inc. All rights reserved.
Image representation using curvature information in intensity profiles
(1997)
Liu, HH
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Twu, JH
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Wang, SJ
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交大名義發表
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電子工程學系及電子研究所
In this paper we present a new approach which represents an intensity profile by using same ''pulley'' points, which are defined as points of high-curvature. The basic concept and the morphological methods for finding these pulley points are introduced. This representation can faithfully keep the spatial information of a profile and greatly reduce the spatial redundancy. We will show some experimental results which demonstrate the promising possibility of using this approach in image compression.
The representation of image surfaces by using curvature information
(1998)
Wang, SJ
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Twu, JH
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Liu, HH
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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
In this paper, we present a novel approach which represents an image by using high-curvature paints of the image surface. The basic concept and the morphological methods for finding these high-curvature points are introduced. This representation can faithfully keep the spatial. information. The reconstruction of the original image using these high-curvature points is successfully developed and demonstrated. We also show a primitive linking process and the experiment results which have demonstrated the promising possibility of using this approach to compactly represent an image.