Browsing by Author "Tsai, CH"

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A due-date oriented scheduling heuristic for job shop cellular manufacturing system
(2000-03-01)
Tsai, CH
;
Li, RK
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Although having gained further insight into scheduling problems involving cellular manufacturing systems, previous research has neglected two characteristics that are essential for effective group scheduling: first, due-date performance focus; second, setup time savings by emphasizing constrained and non-constrained machines. To overcome these two characteristics, we present a due-date oriented scheduling heuristic algorithm for jab shop cellular manufacturing system based on Capacity Constraint Resource (CCR). The proposed algorithm consists of four stages: (1) schedule development for CCR (DRUM), (2) CCR setup time savings to decrease mean tardiness, (3) CCR setup time savings to maximize CCR throughput, and (4) development of a hybrid scheduling method to minimize total flowtime and the work-in-process (WIP) inventory. Also, an illustrative example demonstrates the feasibility of the proposed method. Significance: This study has developed a due-date oriented scheduling heuristic algorithm for job shop cellular manufacturing environments. The proposed algorithm's strong performance indicates that our four-stage group scheduling heuristic, with its more sensitive switching procedures, can not only overcome some of the weaknesses shown by exhaustive and non-exhaustive scheduling heuristics, but can also glean setup time savings without sacrificing due-date performance.
A novel amplifying antenna array using patch-antenna couplers - Design and measurement
(2002-08-01)
Tsai, CH
;
Yang, YCA
;
Chung, SJ
;
Chang, K
;
電信工程研究所
This paper proposes a novel amplifying antenna array using the patch-antenna coupler formed by placing one or two open-ended microstrip lines (coupled lines) near and along the nonradiating edge(s) of a patch antenna. An X-band five-element array with broadside 25-dB Chebyshev radiation is demonstrated. When the input signal is fed to the center element, with most of the power radiating from the antenna, part of it is tapped to the coupled lines, amplified by an FET amplifier, and fed to the next antenna element. This process is repeated after all the antenna elements are fed with suitable power. The amplitude distribution of the fields radiated from the antennas is controlled by the coupling coefficient from the patch to the coupled line, which, in turn, is governed by the coupling length and gap between the patch and line. The measured return loss of the designed five-element array is -27 dB at the center frequency of 10 GHz with 2% 10-dB bandwidth. The radiation pattern possesses a transmitting gain of 15.9 dB, a half-power beamwidth of 17degrees, and a sidelobe level of -22 dB.
A potential-based generalized cylinder representation
(2004-12-01)
Chuang, JH
;
Ahuja, N
;
Lin, CC
;
Tsai, CH
;
Chen, CH
Generalized cylinder (GC) is a class of parametric shapes that is very flexible and capable of modeling many different types of real-world objects, and have subsequently been the focus of considerable research in the vision community. Most of the related works proposed previously have dealt with the recovery of 3D shape description of objects based on the GC representation from one or more 2D image data. Different from the objective of the previous works, in this paper, we will propose a new approach to obtain a GC-based shape description of 3D objects. The proposed approach of deriving the GC axis is a further extension of the potential-based skeletonization approach presented in (IEEE Trans. Pattern Anal. Mach. Intell. 22(11) (2000) 1241). Simulation results demonstrate that the derived GC representation will yield better approximation of object shape than that based on simpler subclasses of GC since there is, in principle, no restriction on the topology of the GC axis and the shape of the cross-sections. (C) 2004 Elsevier Ltd. All rights reserved.
A testing framework for Web application security assessment
(2005-08-05)
Huang, YW
;
Tsai, CH
;
Lin, TP
;
Huang, SK
;
Lee, DT
The rapid development phases and extremely short turnaround time of Web applications make it difficult to eliminate their vulnerabilities. Here we study how software testing techniques such as fault injection and runtime monitoring can be applied to Web applications. We implemented our proposed mechanisms in the Web Application Vulnerability and Error Scanner (WAVES)-a black-box testing framework for automated Web application security assessment. Real-world situations are used to test WAVES and to compare it with other tools. Our results show that WAVES is a feasible platform for assessing Web application security. (c) 2005 Elsevier B.V. All rights reserved.
An approach to smooth foreign agent handoff
(2002-05-01)
Tseng, CC
;
Chi, KH
;
Tsai, CH
;
資訊工程學系
;
Department of Computer Science
For ubiquitous computing and communication, a mobile node needs to change upon movements its network- and link-layer points of attachment to the Internet. Conventionally. the network-layer protocol is unaware of the link-layer changes, so IP datagrams to and from a moving node could be lost. Considerable system performance degradation might therefore result. This paper presents a scheme to integrate the handoff procedures of the two layers in the context of Mobile IP with route optimization. Experiment results show that our scheme is promising and can reduce packet loss due to host migrations substantially.
An effictive and efficient hierarchical fuzzy rule based classifier
(2003)
Tsai, CH
;
Lin, SY
;
Cheng, MH
;
Horng, SC
;
Liu, CH
In this paper, we propose a hierarchical fuzzy rule based classifier (HFRBC) for the classification problem with large number of classes and continuous attributes. A hierarchical clustering concept is introduced to achieve a finer fuzzy partition. Critical attributes are used to perform the cluster splitting and generate a cluster splitting tree. The effective attributes for the terminal clusters in the cluster splitting tree are picked so as to reduce the size of the fuzzy-rule set and hence reduce the computational complexity. The fuzzy rule generation procedures and classification procedures of the proposed HFRBC are simple and easily implemented. We have successfully applied the HFRBC to the classification problem of the working wafers in an ion implanter.
An inventory model with deteriorating items under inflation when a delay in payment is permissible
(2000-01-15)
Liao, HC
;
Tsai, CH
;
Su, CT
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
This study develops an inventory model for initial-stock-dependent consumption rate when a delay in payment is permissible. In the inventory model, shortages are not allowed. The effect of the inflation rate, deterioration rate, initial-stock-dependent consumption rate and delay in payment are discussed. In the study, mathematical models are also derived under two different circumstances, i.e., Case I: The credit period is less than or equal to the cycle time for settling the account; and Case II: The credit period is greater than the cycle time for settling the account. Besides, expressions for an inventory system's total cost are derived for these two cases. Moreover, a computational procedure and GINO (Lasdon et al., ACM Transactions Mathematical Software 4 (1978) 34-50) are proposed to obtain the optimal order size and cycle time. The results can help managers determine the optimal total cost. Finally, a numerical example demonstrates the applicability of the proposed model. (C) 2000 Elsevier Science B.V. All rights reserved.
Angiotensin I-converting enzyme ACE 2350*G and ACE-240*T-related genotypes and alleles are associated with higher susceptibility to endometriosis
(2005-01-01)
Hsieh, YY
;
Chang, CC
;
Tsai, FJ
;
Hsu, CM
;
Lin, CC
Endometriosis displays features similar to malignancy, ranging from neovascularization to local invasion and aggressive spread to distant organs. The altered vascular-related genes might be related to the development of endometriosis. This study investigates whether angiotensin I-converting enzyme (ACE) *A2350G and A-240T gene polymorphisms could be used as markers of susceptibility in endometriosis. Women were divided into two groups: (1) endometriosis group (n=150) and (2) non-endometriosis group (n=159). Genomic DNA was obtained from peripheral leukocytes. ACE A2350G and A-240T gene polymorphisms were amplified by PCR and detected after restriction enzyme digestion with BstUI and XbaI. Genotypes and allelic frequencies in both groups were compared. We observed that genotype distribution and allele frequency of ACE 2350 and ACE-240 gene polymorphisms in both groups were significantly different. Proportions of ACE 2350*A homozygote/heterozygote/G homozygote in both groups were: (1) 66.7/29.3/4% and (2) 96.2/3.1/0.7%. Proportions of ACE-240*A homozygote/heterozygote/T homozygote in both groups were: (1) 43.3/46/10.7% and (2) 62.9/35.8/1.3%. We concluded that ACE 2350*G and ACE-240*T-related genotypes and alleles are associated with higher susceptibility to endometriosis. ACE A2350G and A-240T gene polymorphisms might be associated with endometriosis development.
Bipanconnectivity and edge-fault-tolerant bipancyclicity of hypercubes
(2003-07-31)
Li, TK
;
Tsai, CH
;
Tan, JJM
;
Hsu, LH
;
資訊工程學系
A bipartite graph is bipancyclic if it contains a cycle of every even length from 4 to I V(G) I inclusive. It has been shown that Q(n) is bipancyclic if and only if n greater than or equal to 2. In this paper, we improve this result by showing that every edge of Q(n) - E' lies on a cycle of every even length from 4 to V(G) inclusive where E' is a subset of E(Q(n)) with E' less than or equal to n - 2. The result is proved to be optimal. To get this result, we also prove that there exists a path of length I joining any two different vertices x and y of Qn when h (x, y) less than or equal to l less than or equal to V(G) - 1 and l - h (x, y) is even where It (x, y) is the Hamming distance between x and y. (C) 2003 Elsevier Science B.V. All rights reserved.
Comparative molecular binding energy analysis of HIV-1 protease inhibitors using genetic algorithm-based partial least squares method
(2004)
Chen, YC
;
Yang, JM
;
Tsai, CH
;
Kao, CY
;
生物科技學系
Cycle embedding in faulty wrapped butterfly graphs
(2003-09-01)
Tsai, CH
;
資訊工程學系
;
Department of Computer Science
In this paper, we study the maximal length of cycle embedding in a faulty wrapped butterfly graph BFn with at most two faults in vertices and/or edges. When there is one vertex fault and one edge fault, we prove that the maximum cycle length is n2(n) - 2 if n is even and n2(n) - 1 if n is odd. When there are two faulty vertices, the maximum cycle length is n2(n) - 2 for odd n. All these results are optimal because the wrapped butterfly graph is bipartite if and only if n is even. (C) 2003 Wiley Periodicals, Inc.
Cytochrome P450c17 alpha 5'-untranslated region T/C polymorphism in endometriosis
(2004-08-01)
Hsieh, YY
;
Chang, CC
;
Tsai, FJ
;
Lini, CC
;
Tsai, CH
Estrogen plays a role in the pathogenesis of endometriosis. The CYP17 gene codes for the cytochrome P450cl7alpha enzyme that is involved in the estrogen biosynthesis. We aimed to investigate if CYP 17 polymorphism could be used as marker to predict the susceptibility of endometriosis. Women were divided into two groups: (1) severe endometriosis (n= 119); (2) non-endometriosis groups (n=1 28). A 169-bp fragment encompassing the T/C polymorphic site in 5'-untranslated promoter region (5'-UTR) of the CYP17 was amplified by the polymerase chain reaction, treated with restriction enzyme MspA1I, and electrophoresis. The polymorphism was divided into restriction- enzyme indigestible (T homozygote), T/C heterozygote, and digestible (C homozygote). Genotypes and allelic frequencies for this polymorphism in both groups were compared. We observed a higher but non-significant percentage of T homozygote in the endometriosis women compared with the non-endometriosis women. Proportions of T homozygote/heterozygote/C homozygote for CYP17 in both groups were: (1) 26.1/46.2/27.7% and (2) 17.2/45.3/37.5% (p- value=0.13 1). T allele was related with higher susceptibility of endometriosis. T and C allele frequencies in both groups were: (1) 49.2/50.8%; (2) 39.8/60.2% (p- value=0.046). Despite the CYP17* T allele Appearing to be asscoiated with a trend of increased risk of endometriosis, CYP17 5'-UTR gene polymorphism might not be a useful marker for prediction of endometriosis susceptibility.
Dynamic spatial modeling approach for estimation of internal phosphorus load
(1998-01-01)
Kao, JJ
;
Lin, WL
;
Tsai, CH
;
環境工程研究所
;
Institute of Environmental Engineering
The effect of the pollution load generated internally from a reservoir on the effectiveness of an eutrophication control plan is significant and has gained increasing attention recently. Accurate estimation of the internal load is difficult because of its spatial and temporal variation. A procedure using a dynamic spatial modeling approach is proposed to improve the estimation. A case study of Posan off-stream reservoir is described to demonstrate the implementation of the procedure for data collection and model preparation, field sampling planning and investigation, laboratory analysis for phosphorus releasing rates, model integration of AGNPS and WASP, calibration and verification of the integrated model, and the internal load estimation. The procedure is expected to provide appropriate temporal and spatial phosphorus internal load estimation for an off-stream reservoir. (C) 1998 Elsevier Science Ltd. All rights reserved.
Dynamic spatial modeling approach for estimation of internal phosphorus load
(1998-01-01)
Kao, JJ
;
Lin, WL
;
Tsai, CH
;
環境工程研究所
;
Institute of Environmental Engineering
The effect of the pollution load generated internally from a reservoir on the effectiveness of an eutrophication control plan is significant and has gained increasing attention recently. Accurate estimation of the internal load is difficult because of its spatial and temporal variation. A procedure using a dynamic spatial modeling approach is proposed to improve the estimation. A case study of Posan off-stream reservoir is described to demonstrate the implementation of the procedure for data collection and model preparation, field sampling planning and investigation, laboratory analysis for phosphorus releasing rates, model integration of AGNPS and WASP, calibration and verification of the integrated model, and the internal load estimation. The procedure is expected to provide appropriate temporal and spatial phosphorus internal load estimation for an off-stream reservoir. (C) 1998 Elsevier Science Ltd. All rights reserved.
Effect of a lateral substituent on the mesomorphic properties of ferroelectric side chain liquid crystalline polysiloxanes
(1997-06-01)
Hsu, CS
;
Tsai, CH
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
The synthesis of side chain liquid crystalline polysiloxanes containing oligooxyethylene spacers and (S)-2-methylbutyl 4-[(4-oxybiphenyl-4'-yl)carbonyloxyl-3-fluorobenzoate mesogenic side groups is presented. Differential scanning calorimetry, optical polarizing microscopy and X-ray diffraction measurements reveal liquid crystalline properties for all synthesized monomers and polymers. All three precursor olefinic monomers reveal cholesteric and smectic A phases. The olefinic monomer which contains two oligooxyethylene units in the spacer is the only one which reveals a twist grain boundary A phase and a blue phase, besides the cholesteric and smectic A phases. All three polysiloxanes present enantiotropic smectic A and chiral smectic C phases. The mesomorphic behaviours of the monomers and polymers are compared with those of the corresponding monomers and polymers without the lateral fluoro substituent. The results seem to demonstrate that incorporating a lateral fluoro substituent in the mesogenic cores of the monomers affects not only the mesophase thermal stability, but also the nature of the mesophases formed. However, incorporating a lateral fluoro substituent in the mesogenic cores of the polymers affects only the thermal stability of the mesophases formed. The lateral fluoro substituent has a more profound effect on the mesomorphic behaviour for the monomers than that for the polymers.
Effect of a lateral substituent on the mesomorphic properties of ferroelectric side chain liquid crystalline polysiloxanes
(1997-06-01)
Hsu, CS
;
Tsai, CH
;
應用化學系
;
Department of Applied Chemistry
The synthesis of side chain liquid crystalline polysiloxanes containing oligooxyethylene spacers and (S)-2-methylbutyl 4-[(4-oxybiphenyl-4'-yl)carbonyloxyl-3-fluorobenzoate mesogenic side groups is presented. Differential scanning calorimetry, optical polarizing microscopy and X-ray diffraction measurements reveal liquid crystalline properties for all synthesized monomers and polymers. All three precursor olefinic monomers reveal cholesteric and smectic A phases. The olefinic monomer which contains two oligooxyethylene units in the spacer is the only one which reveals a twist grain boundary A phase and a blue phase, besides the cholesteric and smectic A phases. All three polysiloxanes present enantiotropic smectic A and chiral smectic C phases. The mesomorphic behaviours of the monomers and polymers are compared with those of the corresponding monomers and polymers without the lateral fluoro substituent. The results seem to demonstrate that incorporating a lateral fluoro substituent in the mesogenic cores of the monomers affects not only the mesophase thermal stability, but also the nature of the mesophases formed. However, incorporating a lateral fluoro substituent in the mesogenic cores of the polymers affects only the thermal stability of the mesophases formed. The lateral fluoro substituent has a more profound effect on the mesomorphic behaviour for the monomers than that for the polymers.
Efficient green coumarin dopants for organic light-emitting devices
(2004-04-15)
Lee, MT
;
Yen, CK
;
Yang, WP
;
Chen, HH
;
Liao, CH
[GRAPHICS] We have synthesized a new green fluorescent dopant C-545P having incorporated five strategically placed "methyl" steric spacers on the julolidyl ring system. C-545P has good thermal properties and photostability, and when fabricated as a dopant in an Alq(3)-hosted OLED device, it shows notable improvement in luminance efficiency and is more resistant to concentration quenching than C-545T, particularly in the doping concentration range between 1 and 2% v/v, while achieving comparable device stability.
Estrogen receptor alpha dinucleotide repeat and cytochrorne P450c17 alpha gene polymorphisms are associated with susceptibility to endometriosis
(2005-03-01)
Hsieh, YY
;
Chang, CC
;
Tsai, FJ
;
Lin, CC
;
Tsai, CH
Objective: To investigate the association of endometriosis with estrogen receptor alpha (ER alpha) and cytochrome P450c17 alpha (CYP17) gene polymorphisms in light of the fact that estrogen plays a role in the pathogenesis of endometriosis and the CYP17 enzyme is involved with estrogen biosynthesis. Design: Prospective study. Setting: Genetics and gynecology units. Patient(s): All patients were divided into two groups: group 1, women with endometriosis (n = 119); group 2, normal controls (n = 108). Intervention(s): A dinucleotide (thymine-adenine [TA]) repeat polymorphism lying upstream of the ER alpha gene and A1/A2 polymorphism of the CYP17 gene were amplified by polymerase chain reaction, enzyme restriction, and electrophoresis. Main Outcome Measure(s): The ER Genotypes were classified into A through T (TA repeats, 10-29). The CYP17 genotypes included indigestible (A1 homozygote), heterozygote, and digestible (A2, homozygote). We compared these polymorphism distributions in both groups. Result(s): The percentage of genotypes D-G (TA, 13-16) in both groups were 110.5%, 29.4%, 13.0%, and 11.3% in group 1 and 7.9%, 16.7% 19.9%, and 17.6% in group 2. The genotype E (14 TA repeats) is associated with a higher risk of endometriosis. Proportions of Al homozygote/heterozygote/A2 homozygote for CYP17 were 26.1%/46.2%/27.7% for Group I and 14.8%/44.5%/40.7% for group 2, respectively. The Al homozygote and allele were associated with a higher susceptibility of endornetriosis. Conclusion(s): ER alpha* 14 TA repeats and the CYP17* Al allele are associated with an increased risk of endometriosis. Both polymorphisms are useful markers for predicting endometriosis susceptibility. (Fertil Steril (R) 2005:83:567-72. (c) 2005 by American Society for Reproductive Medicine.)
Exact solution of inventory replenishment policy for a linear trend in demand - two-equation model
(2002-03-21)
Lo, WY
;
Tsai, CH
;
Li, RK
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
This study presents a model for obtaining the exact optimal solution of inventory replenishment policy problem. The proposed model, called the "two-equation model", includes two governing equations and a time-frequency algorithm: the first equation determines the optimal replenishment times for a specified number of replenishments; the second equation determines the optimal number of replenishments. The time-frequency algorithm includes two main procedures to solve the first and second equations. In contrast to many approximation approaches, this model exactly solves the first equation, a simultaneous non-linear equations system using a generalized matrix-based solver. This study also examines the classical no-shortage inventory replenishment policy for linear increasing and decreasing trend demand. According to these results, the solution given by the two-equation model is an exact solution. (C) 2002 Elsevier Science B.V. All rights reserved.
Fault detection and isolation for plasma etching using model-based approach
(2003)
Cheng, MH
;
Huan-Shin, L
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Lin, SY
;
Liu, CH
;
Lee, WY
A fault detection and isolation system using model-based approach for the chamber pressure of plasma etching is developed. The dynamics of chamber pressure is modeled as a linear multiple-input-single-output closed-loop system and the model parameters are extracted by the system identification technique. The obtained parameters are then converted to physically meaningful features for detecting and isolating faults. The fuzzy inference and Dempster-Shafer evidence combining techniques are employed to detect and isolate fault from the features. The system has been evaluated by the measured data that are collected via SECS-II from the employed Lam-490 plasma etcher for processing practical products. The test results are satisfactory for a large amount of practical data and extensive computer simulations.