Browsing by Author "Hsieh, TM"

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A homophonic DES
(1998-06-30)
Hsieh, TM
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Yeh, YS
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Hsieh, YC
;
Wang, CC
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資訊科學與工程研究所
In this paper, we propose a variant of DES called a homophonic DES. The DES algorithm is strengthened by adding some random bits into the plaintext, which are placed in particular positions to maximize diffusion, and to resist differential attack. (C) 1998 Elsevier Science B.V. All rights reserved.
A perspective situation theory
(2000)
Hsieh, TM
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資訊工程學系
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Department of Computer Science
To extend Jon Barwise's simple situation theory, this paper proposes a perspective situation theory which applies the three elements of the perspective drawing - viewpoint, object, projection-plane, and the agent individually views as a situation with some role for situation operations. Utilize the interactions of the situations, we have introduced the subjective cognition of multi-agents system.
Automation of an optical tweezers
(2000)
Hsieh, TM
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Chang, BJ
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Hsu, L
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光電工程學系
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Department of Photonics
Optical tweezers is a newly developed instrument, which makes possible the manipulation of micro-optical particles under a microscope(1). In this paper, we present the automation of an optical tweezers which consists of a modified optical tweezers, equipped with two motorized actuators to deflect a 1W argon laser beam, and a computer control system including a joystick. The trapping of a single bead and a group of lactoacidofilus was shown, separately. With the aid of the joystick and two auxiliary cursors superimposed on the real-time image of a trapped bead, we demonstrated the simple and convenient operation of the automated optical tweezers. assign a new location for the trapped bead to move to. By steering the joystick and then pressing a button on it, we The increment of the motion, 0.04 mu m for a 20X objective, is negligible. With a fast computer for image processing, the manipulation of the trapped bead is smooth and accurate. The automation of the optical tweezers is also programmable. This technique may be applied to accelerate the DNA hybridization in a gene chip(2). The combination of the modified optical tweezers with the computer control system provides a tool for precise manipulation of micro particles in many scientific fields.
One-way hash functions with changeable parameters
(1999-09-01)
Hsieh, TM
;
Yeh, YS
;
Lin, CH
;
Tuan, SH
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資訊工程學系
In this paper, four new algorithms for improvements of MD5 and SHA-Keyed/Unkeyed MD5 and Keyed/Unkeyed SHA are proposed. We change the mode of fixed retrieval of the parameters to that of dynamic retrieval of the parameters by applying a mapping between the index phrase and the parameter table. As shown in the experimental result, with 1% degradation of performance, comparing to the original algorithms, dynamic retrieval of parameters can be achieved. We believe that the security can be increased under the improvements. (C) 1999 Elsevier Science Inc. All rights reserved.