Browsing by Author "Chen, YH"

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A broadband and low cost monolithic BiCMOS tuner chip
(2004-11-01)
Chen, YH
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Cheng, TY
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Chang, CY
;
交大名義發表
;
National Chiao Tung University
This circuit is a single chip of a BiCMOS wafer used in cable TV set-top converters;, cable modems, cable TV tuners and digital TVs. It is a double conversion tuner (DCT) structure which has better performance characteristics than the single conversion tuner (SCT). This single chip comprises two LNAs, one AGC, two LO buffers, two VCOs, two resistor-type and double-balanced Gilbert cell mixers, two synthesizers and ESD protection. Its total gain is 45.70 dB, and its total noise figure is 4.3-7.9 dB. The RF varied range, which is not only 50-860 MHz but also 50-1000 MHz, can be applied in cable TV tuners and cable modems. The consuming power is 0.885 W under 3 V and the die size is 4.8 mm(2).
A dynamic model of ozone disinfection in a bubble column with oxygen mass transfer
(2002-05-01)
Chen, YH
;
Chang, CY
;
Yu, YH
;
Chiang, PC
;
Chiu, CY
The dynamic process of disinfection with ozone in a bubble column is studied for model establishment. Bubble columns have been widely used for ozone disinfection in plants and laboratories. Ozone is produced by passing oxygen-enriched gas through an ozone generator, and introduced into the bottom of a column equipped with a gas-diffuser. There certainly exists a temporary and unsteady period before the ozone disinfection system reaches steady state. Available ozone disinfection models employed to describe dissolved ozone and surviving microorganism profiles have commonly been developed for steady state. Moreover, oxygen mass transfer has usually been neglected in previous ozone disinfection models. However, this information is desirable for the proper operation of ozone disinfection in a bubble column. Thus, the objective of this study was to model and investigate the dynamic ozone disinfection process in a bubble column with oxygen mass transfer. A dynamic axial dispersion model is proposed and was employed to predict the variation of the ozone, microorganism and oxygen concentrations along the column. The results of prediction were obtained based on the conditions of Marinas et al. (1993). E. coli was chosen as the model microorganism. The dynamic model of ozone inactivation is useful for proper prediction of the variables of an ozone disinfection system in a bubble column.
A fully automated web-based TV-News system
(2004)
Lai, PS
;
Lai, LY
;
Tseng, TC
;
Chen, YH
;
Fu, HC
This paper proposes a web-based multimedia TV-News system, which can records and analyzes news video to generate hierarchy news contents automatically. To achieve this goal, various neural network based techniques, including image processing, audio processing, and optical characters recognition are applied. Since July 2003, the multimedia TV-News system has been implemented and continuously been up running at http://nn.csie.nctu.edu.tw/TVNews/intro.htm for general public browsing and studying.
A novel model for quick response to disaster relief distribution
(2005)
Sheu, JB
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Chen, YH
;
Lan, LW
;
運輸與物流管理系註：原交通所+運管所
;
Department of Transportation and Logistics Management
This paper presents a hybrid fuzzy-optimization methodology to solve the large-scale disaster relief distribution problem with the main goal of minimizing the total number of fatalities. The proposed method mainly contains a three-stage operational algorithm. Here fuzzy clustering techniques are used in the first stage to classify the damaged areas based on respective relief demand attributes and priority, followed by the second and the third stage, where fuzzy linear programming is employed to deal with the situation when the demand for victims is greater than the available resources. Results of a numerical study are illustrated to demonstrate the applicability of the proposed method.
A real-time multiple-vehicle detection and tracking system with prior occlusion detection and resolution
(2005)
Wu, BF
;
Lin, SP
;
Chen, YH
;
電控工程研究所
;
Institute of Electrical and Control Engineering
The proposed multiple-vehicle detection and tracking (MVDT) system utilizes a color background to segment moving objects and exploits relations among the moving objects and existed trajectories to track vehicles. Initially, the background is extracted by classification. Then, it is regularly updated by previous moving objects to guarantee robust segmentation in luminance-change circumstance. For partial wrong converged background due to roadside parking vehicles. it will be corrected later by checking fed back trajectories to avoid false detection after the vehicles moving away. In tracking processing, the relations of distances or distances and angles are applied to determine whether to create, extend, and delete a trajectory. If occlusion detected after trajectory creation, it will be resolved by rule-based tracking reasoning. Otherwise, lane information will be used. Finally, traffic parameter calculations based on the trajectories art, listed. Moreover, for easy setup, parameter automation for the system is proposed.
A Self-growing Probabilistic decision-based neural network for anchor/speaker identification
(2003)
Chen, YH
;
Tseng, CL
;
Fu, HC
;
Pao, HT
;
資訊工程學系
In this paper, we propose a new clustering algorithm for a mixture Gaussian based neural network, called Self-growing Probabilistic decision-based neural networks (SPDNN). The proposed Self-growing cluster learning (SGCL) algorithm is able to find the natural number of prototypes based on a self-growing validity measure, Bayesian Information Criterion (BIC). The learning process starts with a single prototype randomly initialized in the feature space and grows adaptively during the learning process until most appropriate number of prototypes are found. We have conduct numerical and real world experiments to demostrate the effectiveness of the SGCL algorithm. In the results of using SGCL to trainin the SPDNN for anchor/speaker identification, we have observed noticeable improvement among various model-based or vector quantization-based classification schemes.
A self-growing probabilistic decision-based neural network with automatic data clustering
(2004-10-01)
Tseng, CL
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Chen, YH
;
Xu, YY
;
Pao, HT
;
Fu, HC
In this paper, we propose a new clustering algorithm for a mixture of Gaussian-based neural network and self-growing probabilistic decision-based neural networks (SPDNN). The proposed self-growing cluster learning (SGCL) algorithm is able to find the natural number of prototypes based on a self-growing validity measure, Bayesian information criterion (BIC). The learning process starts from a single prototype randomly initialized in the feature space and grows adaptively during the learning process until most appropriate number of prototypes are found. We have conducted numerical and real-world experiments to demonstrate the effectiveness of the SGCL algorithm. In the results of using SGCL to train the SPDNN for data clustering and speaker identification problems, we have observed a noticeable improvement among various model-based or vector quantization-based classification schemes. (C) 2004 Elsevier B.V. All rights reserved.
Adaptive watermarking using relationships between wavelet coefficients
(2005)
Chen, YH
;
Su, JM
;
Fu, HC
;
Huang, HC
;
Pao, HT
In this paper, we propose an approach that hides watermarks in relationships between wavelet coefficients. This approach would minimize the perceptual distortion of watermarked images, measured with PSNR or just noticeable distortion (JND). Therefore, the strength of watermarks can be enlarged to increase the robustness of the watermarks, while keeping the quality of watermarked images visually accepted. Experimental results show that the watermark is still detectable after common image processing operations such as JPEG compression, Gaussian filtering and sharpening.
Algorithmic aspects of the generalized clique-transversal problem on chordal graphs
(1996-05-20)
Chang, MS
;
Chen, YH
;
Chang, GJ
;
Yan, JH
;
應用數學系
Suppose G=(V,E) is a graph in which each maximal clique C-i is associated with an integer r(i), where 0 less than or equal to r(i) less than or equal to\C-i\. The generalized clique transversal problem is to determine the minimum cardinality of a subset D of V such that \D boolean AND C-i\greater than or equal to r(i) for every maximal clique C-i of G. The problem includes the clique-transversal problem, the i,1 clique-cover problem, and for perfect graphs, the maximum q-colorable subgraph problems as special cases. This paper gives complexity results for the problem on subclasses of chordal graphs, e.g., strongly chordal graphs, k-trees, split graphs, and undirected path graphs.
Algorithmic aspects of the generalized clique-transversal problem on chordal graphs
(1996-05-20)
Chang, MS
;
Chen, YH
;
Chang, GJ
;
Yan, JH
;
應用數學系
Suppose G=(V,E) is a graph in which each maximal clique C-i is associated with an integer r(i), where 0 less than or equal to r(i) less than or equal toC-i. The generalized clique transversal problem is to determine the minimum cardinality of a subset D of V such that D boolean AND C-igreater than or equal to r(i) for every maximal clique C-i of G. The problem includes the clique-transversal problem, the i,1 clique-cover problem, and for perfect graphs, the maximum q-colorable subgraph problems as special cases. This paper gives complexity results for the problem on subclasses of chordal graphs, e.g., strongly chordal graphs, k-trees, split graphs, and undirected path graphs.
Algorithms for the wafer probing scheduling problem with sequence-dependent set-up time and due date restrictions
(2004-11-01)
Pearn, WL
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Chung, SH
;
Yang, MH
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Chen, YH
;
交大名義發表
In this paper, we consider the wafer probing scheduling problem (WPSP) to sequence families of jobs on identical parallel machines with due date restrictions. The machine set-up time is sequentially dependent on the product types of the jobs processed on the machine. The objective is to minimize the total machine workload without violating the machine capacity and job due date restrictions. The WPSP is a variation of the classical parallel-machine scheduling problem, that can be transformed into the vehicle-routing problem with time windows (VRPTW). One can therefore solve the WPSP efficiently using existing VRPTW algorithms. We apply four existing savings algorithms presented in the literature including sequential, parallel, generalized, and matching based savings, and develop three modifications called the modified sequential, the compound matching based, and the modified compound matching-based savings algorithms, to solve the WPSP. Based on the characteristics of the wafer probing process, a set of test problems is generated for testing purposes. Computational results show that the three proposed modified algorithms perform remarkably well.
Automated information. mining on multimedia TV news archives
(2005)
Lai, PS
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Cheng, SS
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Sun, SY
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Huang, TY
;
Su, JM
This paper addresses an integrated information mining techniques for multimedia TV-news archive. The utilizes techniques from the fields of acoustic, image, and video analysis, for information retrieval on news story title, newsman and scene identification. The goal is to construct a compact yet meaningful abstraction of broadcast news video, allowing users to browse through large amounts of data in a non-linear fashion with flexibility and efficiency. By using acoustic analysis, the system can classify video into news versus commercials, with 90% accuracy on a data set of 400 hours TV-news recorded off the air from July 2003 to August of 2004. By applying speaker identification and/or image detection techniques, each news stories can be segmented with an accuracy of 96%. On screen captions or subtitles are recognized by OCR techniques to produce the text title of each news stories. The extracted title words can be used to link or to navigate more related News contents on the WWW. In cooperation with facial and scene analysis and recognition techniques, OCR results can provide users with multimodality query for specific news stories. Some experimental results are presented and discussed for the system reliability and performance evaluation and comparison.
Capillary electrophoresis, potentiometric and laser excited luminescence studies of lanthanide(III) complexes of 1,7-dicarboxymethyl-1,4,7,10-tetraazacyclododecane (DO2A)
(1998-10-07)
Chang, CA
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Chen, YH
;
Chen, HY
;
Shieh, FK
;
生物科技學系
The protonation constants of the ligand 1,7-dicarboxymethyl-1,4,7,10-tetraazacyclododecane (DO2A) were redetermined by the potentiometric pH titration method (log K 10.94, 9.55, 3.85, 2.55) and the macrocycle ring protonation sites have also been confirmed by NMR techniques to be the secondary amine nitrogen atoms. The stability constants of calcium(II) and all trivalent lanthanide (Ln(3+)) metal complexes of DO2A (Ca2+, log K-ML 7.16; Ln(3+), log K-ML 10.94-13.31) were determined by the potentiometric pH titration and capillary electrophoresis methods, respectively. In general, the stabilities of the Ln(DO2A)(+) complexes increase with increasing atomic number for the lighter lanthanides (La3+-Sm3+) and remain relatively unchanged for the heavier lanthanides (Eu3+-Lu3+). Laser-excited spectroscopy of the F-7(o) --> D-5(o) transition of Eu3+ is used to study the aqueous Eu3+-DO2A complex system. At low pH (e.g. pH 5-6) Eu3+ forms a 1:1 species with the ligand DO2A, presumably Eu(DO2A)(H2O)(q)(+), where q is the number of inner-sphere coordinated water molecules. As the solution pH increases the hydrolysis product, Eu(DO2A)(OH)(H2O)(q-1), is formed. Lifetime measurements of each species in H2O and D2O allow the determination of the corresponding number of inner-sphere coordinated water molecules to be 3.0 and 2.6, consistent with the proposed structures (i.e. q = 3). The first hydrolysis constant (pK(h)) is estimated to be 8.1 +/- 0.3.
Cluster-based support vector machines in text-independent speaker identification
(2004)
Sun, SY
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Tseng, CL
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Chen, YH
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Chuang, SC
;
Fu, HC
Based on Statistical learning theory, Support Vector Machines(SVM) is a powerful tool for various classification problems, such as pattern recognition and speaker identification etc. However, Training SVM consumes large memory and long computing time. This paper proposes a cluster-based learning methodology to reduce training time and the memory size for SVM. By using k-means based clustering technique, training data at boundary of each cluster were selected for SVM learning. We also applied this technique to text-independent speaker identification problems. Without deteriorating recognition performance, the training data and time can be reduced up to 75% and 87.5% respectively.
Cost-effective fabrication of a phase mask by direct etching of the laser-interference grating on fused silica substrate
(2003-09-05)
Lu, YT
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Chen, YH
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Chi, S
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光電工程學系
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Department of Photonics
A simple and cost-effective method to manufacture a phase mask with high diffraction efficiency for deep UV application is proposed. The deep rectangular grating fabricated by using laser interference is etched directly into a fused silica substrate, instead of the dielectric coating on a substrate (done in a previous method). Using the metal layer on a dielectric layer for masking in the deep, dry etching process is also unnecessary in our technique. A fabricated rectangular grating with high diffraction efficiency is presented in this paper. We also demonstrate the fabrication processes and show the optimum parameters for our proposed technology. (C) 2003 Wiley Periodicals, Inc.
Counter-current chromatography using supercritical fluid carbon dioxide as mobile phase
(1996-02-16)
Yu, T
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Li, SE
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Chen, YH
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Wang, HP
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應用化學系
Supercritical fluid carbon dioxide was employed in solar eccentric counter-current chromatography (SECCC) to replace the liquid mobile phase in the traditional arrangement. The fundamental difference from the conventional liquid-liquid system is the requirement for high-pressure operation. The experimental set-up is presented to illustrate the necessary modifications that accommodate operation with a supercritical fluid. Studies on the stationary phase retention due to various experimental conditions are discussed. A mixture of acetophenone and benzophenone was chromatographed using mixtures of water and methanol as the stationary solvent system to demonstrate the feasibility of this technique. At present the efficiency of the separation is not satisfactory owing to the phase separator inserted in the system to remove liquid droplets which contributed to considerable peak broadening.
Coupling-efficiency analysis and control of dual antiresonant reflecting optical waveguides
(1996-06-01)
Chen, YH
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Huang, YT
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
We have developed the necessary theory to analyze the coupling efficiency of dual ARROW waveguide. Based on the theory, we have found that the coupling efficiency of dual ARROW waveguides can be flexibly controlled from a 100% value to zero by simply varying the outermost cladding thickness. BPM simulations also give same results and verify the theory. The theory and simulation results can be efficiently applied to designing an ARROW power divider with any specified power ratio.
Decomposition of 2-mercaptothiazoline in aqueous solution by ozonation
(2004-07-01)
Chen, YH
;
Chang, CY
;
Chen, CC
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Chiu, CY
;
Yu, YH
This study investigates the ozonation of 2-mercaptothiazoline (2-MT). The 2-MT is one of the important organic additives for the electroplating solution of the printed wiring board industry and has been widely used as a corrosion inhibitor in many industrial processes. It is of concern for the aquatic pollution control especially in the wastewaters. Semibatch ozonation experiments in the completely stirred tank reactor are performed under various concentrations of input ozone. The concentrations of 2-MT, sulfate, and ammonium are analyzed at specified time intervals to elucidate the decomposition of 2-MT during the ozonation. In addition, the time variation of the dissolved ozone concentration (C-ALb) is continuously monitored in the course of experiments. Total organic carbon (TOC) is chosen and measured as a mineralization index of the ozonation of 2-MT. The results indicate that the decomposition of 2-MT is efficient, while the mineralization of TOC is limited via the ozonation only. Simultaneously, the yield of sulfate with the maximum value of about 47% is characterized by the increases of TOC removal and ozone consumption. These results can provide some useful information for assessing the feasibility of the treatment of 2-MT in the aqueous solution by the ozonation. (C) 2004 Elsevier Ltd. All rights reserved.
Decomposition of 2-naphthalenesulfonate in aqueous solution by ozonation with UV radiation
(2002-09-01)
Chen, YH
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Chang, CY
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Huang, SF
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Chiu, CY
;
Ji, D
This study investigates the ozonation of 2-naphthalenesulfonate (2-NS) combined With ultraviolet (UV) radiation, Naphthalenesulfonic acids are of importance as dye intermediates for the dye and textile auxiliary industries. Its derivatives, such as 2-NS. have been found in rivers and tannery effluents causing Pollution problems. Thus, the 2-NS is of concern for the aquatic pollution control especially in the surface and waste waters. Ozonation combined with UV radiation is employed for the removal of 2-NS in the aqueous solution. Semibatch ozonation experiments were proceeded under different reaction conditions to studs the effects of ozone dosage and UV radiation on the oxidation of 2-NS. The concentrations of 2-NS and sulfate are analyzed at specified time internals to elucidate the decomposition of 2-NS. In addition, values of pH and oxidation reduction potential are continuously Measured in the course of experiments. Total organic carbon is chosen as a mineralization index of the ozonation of 2-NS, The mineralization of 2-NS via the ozonation is remarkably enhanced by the UV radiation. These results can provide useful information for the proper removal of 2-NS in the aqueous solution by the ozonation with UV radiation. (C) 2002 Published by Elsevier Science Ltd.
Dynamic behavior of ozonation with pollutant in a countercurrent bubble column with oxygen mass transfer
(2003-06-01)
Chen, YH
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Chang, CY
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Chiu, CY
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Yu, YH
;
Chiang, PC
The dynamic behavior of ozonation with pollutants in a countercurrent bubble column is studied for the model establishment. Bubble columns have been widely used for an ozonation system in the plants and laboratories. In addition, a countercurrent bubble column has been commonly recommended than a cocurrent one because it has a higher ozone transfer efficiency. Therefore, the investigation of this paper focuses on the countercurrent bubble column. As an ozonation process starts, the gas mixture of ozone and oxygen is introduced into the bottom of a column, and then transferred into the liquid. The pollutants in the wastewater are eliminated subsequently via oxidation by the dissolved ozone. There certainly exists a temporary and unsteady period before the ozonation system reaches steady state. However, available ozonation models employed to describe ozone and pollutant profiles have commonly been developed for steady state. The treating qualities of wastewater in the early stage of ozonation are usually not predicted, and the time required for the steady-state establishment remains to be determined. Moreover, oxygen mass transfer is usually neglected in previous ozonation models so that the increase of dissolved oxygen is uncertain. These information is desirable for the proper design and operation of ozonation system in a bubble column. Thus, the aim of this study is to model and investigate the dynamic processes of ozonation with pollutants including oxygen mass transfer. The dynamic axial dispersion model proposed is employed to predict the variation of the ozone, pollutant, and oxygen concentrations profiles. The validity of the model was demonstrated by comparing the predicted results with the experimental data. The o-cresol was chosen as the model pollutant. The temporal concentration variations of the residual o-cresol and dissolved oxygen in the effluent liquid, and the off-gas ozone in the free volume were measured accordingly. Furthermore, the variation of the enhancement factor of ozone and the amount of off-gas were predicted. Note that it usually needs 2-5 hydraulic retention times to approach steady state under the conditions of this study. Further, the effects of dimensionless system parameters on the performance of the ozonation processes are examined. As a result, the proposed dynamic model of ozonation with pollutants is useful for proper prediction of the variables of an ozonation system in a countercurrent bubble column. (C) 2003 Elsevier Science Ltd. All rights reserved.