Browsing by Author "Chang, CC"

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A case study in the design of BTO/CTO shop floor control system
(2003-10-01)
Chen, RS
;
Lu, KY
;
Yu, SC
;
Tzeng, HW
;
Chang, CC
Although computerized information systems are conventionally used to control production, applying a manual approach and improper logistical assignments typically reduces operating efficiency and increases customer service response time. Satisfying the requirements of remaining competitiveness in the current marketplace, such as offering build-to-order (BTO) or configuration-to-order (CTO) services is difficult. This study presents an integrated information system for use in shop floor controlling systems (SFCS) for kitting parts, producing goods, packing finished goods and distributing them, to enhance the performance of the BTO/CTO production system. Several information technologies and devices, such as barcode system, the electronic pick-to-light picking system, electronic Kanban (eKanban), and others are adopted to support the relevant logistics. A personal computer (PC) manufacturer is used to demonstrate the proposed system. The findings of the study reveal that the proposed information system can respond to the status of the production line in real time. This responsiveness can help the production controller to make a suitable decision and quickly meet the requirements of the BTO/CTO production system. (C) 2003 Elsevier Science B.V. All rights reserved.
A new efficient algorithm for singular value decomposition
(1999)
Chen, SG
;
Chang, CC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The popular CORDIC-based SVDs suffer from the disadvantages of inherently sequential operations and requiring area-consuming barrel shifters. On the other hand, the basic-arithmetic SVD needs nasty division and square-root operations. To alleviate these problems, a new algorithm for SVD computation is proposed. Instead of using CORDIC algorithm, the new algorithm is based on multiplication-and-addition operations (without nasty division and square-root operations), combined with an approximate rotation and table lookup scheme, As a result, the new algorithm has a smaller computational complexity than those of the conventional SVD algorithms, in terms of number of addition operations. In realization, it also has a higher parallelism and smaller area than the conventional CORDIC-based SVD processors.
A new subliminal channel based on Fiat-Shamir's signature scheme
(1995-11-01)
Chen, CY
;
Chang, CC
;
Yang, WP
;
資訊工程學系
;
Department of Computer Science
This paper constructs a subliminal channel in a RSA-like variant of the Fiat-Shamir signature scheme to transfer any secret information. The proposed subliminal channel, unlike that in El-Gamal signature scheme, can avoid the serious shortcoming that a subliminal receiver can undetectably forge a signer's signature. In addition, our channel also overcomes almost all shortcomings from which the subliminal channel in El-Gamal signature scheme suffer.
A new subliminal channel based on Fiat-Shamir's signature scheme
(1995-11-01)
Chen, CY
;
Chang, CC
;
Yang, WP
;
資訊工程學系
;
Department of Computer Science
This paper constructs a subliminal channel in a RSA-like variant of the Fiat-Shamir signature scheme to transfer any secret information. The proposed subliminal channel, unlike that in El-Gamal signature scheme, can avoid the serious shortcoming that a subliminal receiver can undetectably forge a signer's signature. In addition, our channel also overcomes almost all shortcomings from which the subliminal channel in El-Gamal signature scheme suffer.
A semantic differential study of designers' and users' product form perception
(2000-04-01)
Hsu, SH
;
Chuang, MC
;
Chang, CC
;
應用藝術研究所
;
工業工程與管理學系
This study investigated the differences in the product form perception of designers and users. The semantic differential (SD) method was employed to examine the relationship between the subjects' evaluation of telephone samples and form design elements. The authors used 14 image-word pairs for the evaluation of telephone design. The format for a measurement scale was constructed by a projection method in order to extract design attributes for an SD test. Twenty-four real telephone samples were presented to 40 subjects (20 designers and 20 users) for subjective evaluation. Multivariate analyses were performed to analyze the subject's perceptions and to build conceptual models for telephone design. The result revealed that many differences exist between designers' and users' perceptions of the same real objects and their interpretations of the same image-words. Users are not clear regarding the meaning of the image-words. Moreover, they are very concerned about whether a telephone looks new. Designers tend to value telephone samples with an elegant style while users prefer modern and sleek designs. The conceptual models of the two subject groups are made up of different components. Creative, mature, delicate design images play a greater role in affecting the designers' preference while the users' preference is affected mainly by images of delicacy. The implications of differences in preference and the relationship between image-word and actual design elements for the two subject groups are discussed. Relevance to industry It is the users' needs and preferences, not those of the designers, that should be taken into consideration during the product design process. Due to the fact that many differences exist between designers and users, it is a challenge for designers to transfer the consumer's needs into technical and design specifications. Quantitative data on the relationship between design elements and user evaluations is useful to product designers and managers in formulating design strategies. (C) 2000 Elsevier Science B.V. All rights reserved.
A Web-based monitor and management system architecture for enterprise virtual private network
(2005-11-01)
Chen, RS
;
Hsu, CJ
;
Chang, CC
;
Yeh, SW
;
資訊管理與財務金融系註：原資管所+財金所
Virtual private network (VPN) not only possesses the low cost, inexpensive fees, and excellent support advantages of the Internet, it also has the benefit of the security as the leased line. How to properly manage the VPN is an issue in which the enterprise IT engineers have to take seriously. This research is based on the new network management technologies such as policy-based network management, mobile agent, etc., to design a VPN monitor and management system architecture that contains high level management with low network traffic load. This system architecture integrates both VPN devices and general network devices, such the feature can integrate the monitor and manage the VPN and Intranet at the same time. The result of this research provides enterprises with a VPN architecture for monitoring and managing the enterprises, as well as to establish a prototype for the enterprise VPN monitor and management system. Such system architecture can effectively assist the semiconductor companies to monitor and manage their enterprise VPN in order to utilize the Internet resources, and to reduce the possible operation off time. The prototype system could proof the feasibility of the systematic architecture, it can automatically detect and activate the backup mechanism according to the preset management policy, and to achieve the effective and fast solution for the enterprise network problems. (c) 2005 Elsevier Ltd. All rights reserved.
A web-based monitor and management system architecture for enterprise Virtual Private Network
(2005-01-01)
Chen, RS
;
Chang, CC
;
Yeh, SW
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
This research is based on the new network management technologies such as Policy-based Network Management, Mobile Agent, etc., to design a VPN monitor and management system architecture that is suitable for the enterprise use and contains high level management with low Network Traffic load. This system architecture integrates the monitor and management for both VPN devices and general network devices, such the feature makes enterprise can integrate the monitor and manage the VPN and Intranet at the same time and solve the problems caused by using the VPN. The results of this research provide a VPN system architecture for monitoring and managing the enterprises and establish a prototype for the enterprise VPN` monitor and management system.
An accuracy enhancement algorithm for hierarchical radiosity
(1998-03-01)
Chang, CC
;
Shih, ZC
;
資訊工程學系
;
Department of Computer Science
In this research, we propose an algorithm to enhance the accuracy of the hierarchical radiosity. The proposed approach particularly creates links on the hierarchy in a bottom-up fashion according to both a user-specified error tolerance and the minimum patch area. It differs from the original hierarchical method that creates the links in a top-down manner. In our approach, the upper-level patches have more accurate estimates of the kernel. More accurate error bounds can be obtained for the upper-level patches. These error bounds make the creation of links on the hierarchy more accurate. Furthermore, more accurate form factors can also be obtained for the upper-level patches. Thus, we enhance the accuracy of hierarchical radiosity. (C) 1998 Elsevier Science Ltd. All rights reserved.
An efficient dynamic threshold scheme
(1996-07-01)
Hwang, SJ
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Chang, CC
;
Yang, WP
;
交大名義發表
;
資訊工程學系
To improve the efficiency for the threshold schemes, the major problem is that the secret shadows cannot be reused after renewing or recovering the shared secret. However, if the secret shadows cannot be reused, the established threshold scheme is limited to be used only once. It is inefficient to reconstruct the whole secret sharing system. Therefore, we introduce an efficient dynamic threshold scheme. In the new scheme, the shadowholders can reuse the secret shadows no matter that the shared secret is renewed or recovered. In addition, the new scheme provides a way by which the dealer can renew the shared secret or reconstruct the secret sharing system, efficiently. Therefore, this scheme is good for maintaining the important secrets.
An efficient VLIW DSP architecture for baseband processing
(2003)
Lin, TJ
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Chang, CC
;
Lee, CC
;
Jen, CW
;
電子工程學系及電子研究所
The VLIW processors with static instruction scheduling and thus deterministic execution times are very suitable for high-performance real-time DSP applications. But the two major weaknesses in VLIW processors prevent the integration of more functional units (FU) for a higher instruction issuing rate - the dramatically growing complexity in the register file (RF), and the poor code density. In this paper, we propose a novel ring-structure RF, which partitions the centralized RF into 2N sub-blocks with an explicit N-by-N switch network for N FU. Each sub-block only requires access ports for a single FU We also propose the hierarchical VLIW encoding with variable-length RISC-like instructions and NOP removal. The ring-structure RF saves 91.88% silicon area and reduces 77.35% access time of the centralized RF. Our simulation. results show that the proposed instruction set architecture with the exposed ring-structure RF has comparable performance with the state-of-the-art DSP processors. Moreover, the hierarchical VLIW encoding can save 32%similar to50% code sizes.
An encryption/multisignature scheme with specified receiving groups
(1998-03-01)
Hwang, SJ
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Chen, CY
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Chang, CC
;
資訊工程學系
;
Department of Computer Science
In this paper, we propose a new multisignature scheme that allows all of the signers to specify the recipients. The encryption function is also integrated into our multisignature scheme, thus the new scheme can provide secrecy, authenticity, and integrity services. Moreover, the message expansion is also reduced. Comparing to the proposed multisignature scheme, the new scheme is the first one which allows the singers to specify the recipients.
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.
Asymmetric 2+1 pass stereo matching algorithm for real images
(2006-05-01)
Chu, C
;
Chang, CC
;
資訊工程學系
;
Department of Computer Science
An asymmetric 2+1 pass stereo matching algorithm is proposed for generating a depth map from the input of two real stereo images. In the first pass, the Canny edge detector is used to acquire edge images from the inputs. Component images are then generated from the edge images. The edges of each component in the left component image are cut to obtain asymmetric left and right component images. The concept of a disparity-space image (DSI) by components is introduced and dynamic programming (DP) techniques are applied to match the asymmetric left and right component images. In the second pass, the previous DSI is modified, applying the DP methods to acquire the matched pixel pairs of the matched component pairs, and to generate ground control pairs (GCPs). In the final pass, these GCPs are incorporated into the DP algorithms to determine the optimal path and acquire the depth image. The results show that the proposed approach produces reliable and efficient matching and preserves the shapes of objects effectively for real stereo images. The proposed algorithm makes contours clearer than other conventional methods for real stereo images. (C) 2006 Society of Photo-Optical Instrumentation Engineers.
Authenticated encryption schemes with message linkage
(1996-05-27)
Hwang, SJ
;
Chang, CC
;
Yang, WP
;
資訊工程學系
;
Department of Computer Science
Authenticated encryption schemes need redundancy schemes to link up the message blocks; however, these redundancies increase communication costs. To construct links without increasing communication costs, we propose a general solution for all the authenticated encryption schemes based on the discrete logarithm problem. Because the computation cost to construct links is small, the improved scheme adopting our solution is almost as efficient as the original one, Moreover, by our solution, the recipient can easily determine the missing message blocks, and then acknowledge the sender to send only these blocks again. The communication cost will be also reduced. Adopting our solution, we also propose two new authenticated encryption schemes with message linkage.
Authenticated encryption schemes with message linkage
(1996-05-27)
Hwang, SJ
;
Chang, CC
;
Yang, WP
;
資訊工程學系
;
Department of Computer Science
Authenticated encryption schemes need redundancy schemes to link up the message blocks; however, these redundancies increase communication costs. To construct links without increasing communication costs, we propose a general solution for all the authenticated encryption schemes based on the discrete logarithm problem. Because the computation cost to construct links is small, the improved scheme adopting our solution is almost as efficient as the original one, Moreover, by our solution, the recipient can easily determine the missing message blocks, and then acknowledge the sender to send only these blocks again. The communication cost will be also reduced. Adopting our solution, we also propose two new authenticated encryption schemes with message linkage.
Broadcasting secrets in communication networks
(1998-03-01)
Chang, CC
;
Wu, TC
;
Yeh, YS
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
One property of a broadcast channel is that a single message broadcasted from an originator may be received simultaneously by several recipients in communication links. Based on the Chinese remainder theorem (CRT), we propose a new secure broadcasting scheme to distribute different secrets in one single broadcasting transaction such that each of the secrets is dedicated to different authorized recipients. On receiving the ciphertext broadcasted by the originator, only authorized recipients can obtain and authenticate their dedicated secrets individually, while no secret is revealed to unauthorized recipients. In a single broadcasting transaction, each authorized recipient cannot know who are the other intended recipients for this transaction. Furthermore, the processes for decryption and authentication of the dedicated secret are performed through simple arithmetic computation, i.e., modular operations, hence it is suitable for the applications that the recipient has less computing power. We also show that the proposed scheme can withstand the attack on replaying a previously intercepted broadcasting message.
Cytochrome P450c17 alpha 5'-untranslated region T/C polymorphism in endometriosis
(2004-08-01)
Hsieh, YY
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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.
Data mining application in customer relationship management of credit card business
(2005)
Wu, RC
;
Chen, RS
;
Chang, CC
;
Chen, JY
;
資訊管理與財務金融系註：原資管所+財金所
First, we classify the selected customers into clusters using RFM model to identify high-profit, gold customers. Subsequently, we carry out data mining using association rules algorithm. We measure the similarity, difference and modified difference of mined association rules based on three rules, i.e. Emerging Patten Rule, Unexpected Change Rule, and Added/Perished Rule. In the meantime, we use rule matching threshold to derive all types of rules and explore the rules with significant change based on the degree of change measured. In this paper, we employ data mining tools and effectively discover the current spending pattern of customers and trends of behavioral change, which will allow management to detect in a large database potential changes of customer preference, and provide as early as possible products and services desired by the customers to expand the clientele base and prevent customer attrition.
Determination of head pose and facial expression from a single perspective view by successive scaled orthographic approximations
(2002-02-01)
Chang, CC
;
Tsai, WH
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資訊工程學系
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Department of Computer Science
Human faces are the main organs for expressing human emotion. In this study, anew iterative approach to analyzing the head pose and the facial expression of a human face from a single image is proposed. The proposed approach extends the concept of successive scaled orthographic approximations. which was used to estimate the pose of a rigid object, to develop a method to estimate the parameters for a non-rigid object, namely, a human face. The implementation of the proposed method is simple; furthermore, no initial guess is required. The convergency property of the proposed method is also analyzed theoretically and experimentally. Experimental results show that the proposed method is robust and has a high percentage of convergency, and thus prove the feasibility of the proposed approach.
Direct COSi2 thin-film formation with homogeneous nanograin-size distribution by oxide-mediated silicidation
(2004-09-01)
Chang, JJ
;
Liu, CP
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Chen, SW
;
Chang, CC
;
Hsieh, TE
By annealing at 460 degreesC for 120 s followed by 600 degreesC 120 s, nanocrystalline CoSi2 thin film with an average grain size of 5 nm can be directly formed from a Co/SiOx/Si multilayer with the SiOx, as a mediated layer. It is found that annealing at 460 degreesC for enough time is crucial for generating enough diffusion channels within the SiOx, layer. After these channels are created, subsequent annealing at 600 degreesC keeps these channels open and is responsible for rapid grain growth. In other words, by using two-step annealing, nucleation and growth processes can be effectively controlled and, hence, the resulting microstructure. The homogeneous nanograin-size distribution is important for ultralarge-scale integration technology below 90 nm to prevent resistance degradation induced by CoSi2, agglomeration. (C) 2004 American Vacuum Society.