Browsing by Author "Chen, JH"

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3-port polarization-independent optical quasi-circulator with holographic spatial walk-off polarizers
(2004)
Chen, JH
;
Chen, KH
;
Hsieh, PJ
;
Su, DC
;
光電工程學系
An alternative type of 3-port polarization-independent optical quasi-circulator by utilizing a pair of holographic spatial walk-off polarizers (HSWPs). is proposed. This device consists of a reflection Prism, three polarization beamsplitter cubes, a pair of HSWPs, a Faraday rotator, and a half-wave, plate. The operating principles, the characteristics, and the performances: of this device and HSWPs are discussed. In order to show the validity, the prototype device operating in 1300nm is assembled and tested, experimentally. The merits of this design include polarization-independence, compactness, high isolation, and easy fabrication. It should also be possible to design the device operating at 1550 nm wavelength range.
A framework of features selection for the case-based reasoning
(2000)
Chen, WC
;
Tseng, SS
;
Chen, JH
;
Jiang, MF
;
資訊工程學系
CBR is a problem solving technique that reuses past cases and experiences to find a solution to the problems. A critical issue in case-based reasoning is to select the correct and enough features to represent a case. For this reason, the analysis of cases and extraction the necessary features to represent a case are highly recommended in building a CBR system. However, this task is difficult to carry out since such knowledge often cannot be successfully and exhaustively captured and represented. In this paper, a framework of features mining system for the case-based reasoning including two phases has been proposed. The techniques of features selection, data analysis and machine learning can thus be effectively integrated. This will promote flexibility and expandability of case-based reasoning system.
A modified transfer matrix method for the coupling lateral and torsional vibrations of symmetric rotor-bearing systems
(2006-01-03)
Hsieh, SC
;
Chen, JH
;
Lee, AC
;
機械工程學系
;
Department of Mechanical Engineering
This study develops a modified transfer matrix method for analyzing the coupling lateral and torsional vibrations of the symmetric rotor-bearing system with an external torque. Euler's angles are used to describe the orientations of the shaft element and disk. Additionally, to enhance accuracy, the symmetric rotating shaft is modeled by the Timoshenko beam and considered using a continuous-system concept rather than the conventional "lumped system" concept. Moreover, the harmonic balance method is adopted in this approach to determine the steady-state responses comprising the synchronous and superharmonic whirls. According to our analysis, when the unbalance force and the torque with nx frequency of the rotating speed excite the system simultaneously, the (n + 1) x and (n - 1) x whirls appear along with the synchronous whirl. Finally, several numerical examples are presented to demonstrate the applicability of this approach. (c) 2005 Elsevier Ltd. All rights reserved.
A novel approach to production planning of flexible manufacturing systems using an efficient multi-objective genetic algorithm
(2005-06-01)
Chen, JH
;
Ho, SY
;
生物資訊及系統生物研究所
;
Institude of Bioinformatics and Systems Biology
In this paper, a novel approach using an efficient multi-objective genetic algorithm EMOGA is proposed to solve the problems of production planning of flexible manufacturing systems (FMSs) having four objectives: minimizing total flow time, machine workload unbalance. greatest machine workload and total tool cost. EMOGA makes use of Pareto dominance relationship to solve the problems without using relative preferences of multiple objectives. High efficiency of EMOGA arises from that multiple objectives can be optimized simultaneously Without using heuristics and a set of good non-dominated Solutions can be obtained providing additional degrees of freedom for the exploitation of resources of FMSs. Experimental results demonstrate effectiveness of the proposed approach using EMOGA to]production planning of FMSs. (c) 2004 Elsevier Ltd. All rights reserved.
A physical model for the correlation between holding voltage and holding current in epitaxial CMOS latch-up
(1998-08-01)
Chen, MJ
;
Lee, HS
;
Chen, JH
;
Hou, CS
;
Lin, CS
A new physical model concerning the holding points for latch-up in epitaxial CMOS structures is established by combining the lateral p-i-n high level injection and the vertical BJT base push-out formula. The model matches adequately the correlation between holding voltage and holding current extensively measured from different combinations of temperatures, epitaxial layer thicknesses, and anode-to-cathode spacings, This is also the case for the two-dimensional device simulations. A quantitative analysis based on the model consistently judges the crucial role of the vertical BJT base push-out width in producing the observed correlation. The potential merits of the model in extended applications are outlined.
A system dynamics model of the semiconductor industry development in Taiwan
(2005-10-01)
Chen, JH
;
Jan, TS
;
管理科學系
;
Department of Management Science
Taiwan has become the fourth largest semiconductor manufacturer worldwide within only 25 years. Taiwan's success in developing its semiconductor industry has been widely recognized. Building a semiconductor industry in a developing country is costly, risky, and requires long-term accumulations of capital, technology, human resources, and production capacity. The development process depends on environmental interactions, which should be studied in an integrated and holistic manner. Using system dynamics methodology, this study analyses the development experience of the Taiwanese semiconductor industry, in order to provide better insight into the long-term industrial development process. The study also simulates the proposed model in one historical setting and two future scenarios. Implications for the development of the semiconductor industry in Taiwan and other Asian countries are discussed.
A trap generation closed-form statistical model for intrinsic oxide breakdown
(2001-06-01)
Huang, HT
;
Chen, MJ
;
Su, CW
;
Chen, JH
;
Hou, CS
A trap generation statistical model with the trap sphere radius r as parameter has been newly formulated in closed-form for intrinsic breakdown of ultrathin oxides and, by incorporating the trap filling fraction p as the secondary parameter, can be practically useful in a manufacturing process. Experimental reproduction for different oxide thicknesses and areas has been achieved through the model. A certain criterion has readily been drawn from the model, with which the ultimate thickness limit for breakdown can be set.
A variety-increasing view of the development of the semiconductor industry in Taiwan
(2005-09-01)
Chen, JH
;
Jan, TS
;
管理科學系
;
Department of Management Science
The development of the semiconductor industry depends on its interactions with the environment. Developing countries face more constraints and the environmental interactions seem more complicated. The development process of the semiconductor industry could be better understood with regard to the interactions and social changes. This study proposes a variety-increasing viewpoint based on the concepts of variety increasing and internal learning to analyze the developmental experience of the semiconductor industry in Taiwan. The result shows that the development of Taiwanese semiconductor industry is a continuous variety-increasing process, which is achieved by searching and establishing successful associations in an increasingly wider and complex environment. Implications on the ongoing development of Taiwan's semiconductor industry and the development experiences of other East Asian countries are discussed. (c) 2004 Elsevier Inc. All rights reserved.
All-optical data format conversion in synchronously modulated single-mode Fabry-Perot laser diode using external injection-locking-induced nonlinear threshold reduction effect
(2005-06-01)
Lin, GR
;
Chang, YC
;
Lin, YH
;
Chen, JH
;
光電工程學系
High-speed all-optical data-format conversion and logic gate from a synchronously modulated Fabry-Wrot laser diode (FPLD) below threshold condition is demonstrated by using external injection-induced. nonlinear threshold reduction effect of the FPLD. A pulsed pseudoreturn-to-zero (PRZ) data with maximum extinction ratio of 14.5 dB is obtained by externally seeding the 9.953-Gb/s (OC-192) nonreturn-to-zero (NRZ) data stream to optically gain-switch the FPLD. At optimized radio frequency and optical injecting powers of 24 and 4 dBm, the root mean square timing jitter and the duty-cycle (pulsewidth) of the PRZ eye pattern are determined as 0.4 ps and 45% (44 ps), respectively. The bit-error rate (BER) can be as low as 10(-13) under the 4-dBm external injecting power. A 1.5-dB power penalty with the BER of < 10(-9) is measured at a bit rate of 9.953 Gb/s. Highest NRZ-to-PRZ conversion rate of 12.5 Gb/s is achieved by increasing biasing current of the FPLD.
All-optical NRZ-to-PRZ format transformer with an injection-locked Fabry-Perot laser diode at unlasing condition
(2004-09-20)
Chang, YC
;
Lin, YH
;
Chen, JH
;
Lin, GR
;
光電工程學系
By using an optical nonreturn-to-zero (NRZ) format data-stream to injection-lock an synchronously modulated Fabry-Perot laser diode at below threshold condition (without DC driving current), an output data-stream with pseudo-return-to-zero (PRZ) format can be generated at bit rate of up to 2.488 Gbit/s. Such an NRZ-to-PRZ format transformation is due to the injection-locking induced gain-switching of the FPLD with the incoming NRZ data. The PRZ data-stream with a maximum on/off extinction ratio of 12.2 dB is obtained under the optical injecting power of -2 dBm and the RF driving power of 24.4 dBm. The best side-mode suppression ratio of 40 dB and the lowest timing jitter of 0.4 ps for the PRZ data-stream are observed. A power penalty of 1.2 dB is measured at a bit-error rate of 10(-9) after NRZ-to-PRZ transformation. In application, the demonstration of an all-optical OR logic gate using the FPLD-based NRZ-to-PRZ transformer is also reported. (C) 2004 Optical Society of America.
An efficient probabilistic dynamic multicast routing in ATM networks
(1999-07-01)
Wang, KC
;
Chen, JH
;
資訊工程學系
;
Department of Computer Science
In this paper, we propose a dynamic multicast routing algorithm based on probability for multimedia communications in an asynchronous transfer mode (ATM) network environment. For multimedia communications, we not only aim to arrange a transmission path with the minimal cost from a source node to each destination node, but also consider the dynamic multicast situation with node joining/leaving. To meet the above requirements, we develop a new method based on the relative probability of each node being truncated from the multicast connection tree, such that we can arrange a better path for a new joining node in such a way as to reduce the impact of leaving requests caused by other nodes in the multicast connection tree. The main contribution of this paper is a new and efficient dynamic multicast routing algorithm for multimedia communications which keeps the whole multicast connection tree near optimal in terms of cost inefficiency and guarantees that the transmission delay will be less than the preset bounded end-to-end delay. Simulation results show that under various sizes of networks and requests, the cost inefficiency of the multicast connection tree constructed by our approach is less than those of the trees constructed by the greedy algorithm and the weighted greedy algorithm, respectively.
Characteristics of polysilicon oxides combining N2O nitridation and CMP processes
(2000-08-01)
Lei, TF
;
Chen, JH
;
Wang, MF
;
Chao, TS
;
電子工程學系及電子研究所
This paper present a high-quality polysilicon oxide combining N2O nitridation and chemical mechanical polishing (CMP) processes. Experimental results indicate that polyoxide grown on the CMP sample exhibits a lower leakage current, higher dielectric breakdown field, higher electron barrier height, less electron trapping rate, higher charge-to-breakdown (Q(bd)), and lower density of trapping charge than those of non-CMP samples. In addition, the CMP process enhances nitrogen incorporation at the interface by the N2O nitridation, ultimately improving the polyoxide quality, Moreover, the CMP process smooths the surface of polysilicon and this planar surface reduces the out-diffusion of the phosphorous during thermal oxidation.
Characteristics of TEOS polysilicon oxides: Improvement by CMP and high temperature RTA N-2/N2O annealing
(2000-11-01)
Chen, JH
;
Lei, TF
;
Chen, JH
;
Chao, TS
;
電子工程學系及電子研究所
The integrity of tetraethylorthosilicate (TEOS) polyoxide using chemical mechanical polishing (CMP) plus a high temperature rapid thermal annealing (RTA) step was studied in this work. The surface morphology of polysilicon is improved after a CMP process. Polyoxides deposited by low pressure chemical vapor deposition (LPCVD) TEOS in conjunction with CMP and RTA N-2/N2O annealing exhibit a better current-electric field (J-E) curve, higher charge to breakdown ratio, and lower electron trapping rate. In addition, the composite bilayer (TEOS deposited and thermally grown by RTA) polyoxide film introduces an asymmetry of electrical leakage current, trapping characterization, and charge to breakdown, with respect to the injection of different polarity (+V-g and -V-g) (C) 2000 The Electrochemical Society. S0013-4651(00)01-051-X. All rights reserved.
Design of nearest neighbor classifiers: multi-objective approach
(2005-07-01)
Chen, JH
;
Chen, HM
;
Ho, SY
;
生物資訊及系統生物研究所
;
Institude of Bioinformatics and Systems Biology
The goal of designing optimal nearest neighbor classifiers is to maximize classification accuracy while minimizing the sizes of both reference and feature sets. A usual way is to adaptively weight the three objectives as an objective function and then use a single-objective optimization method for achieving this goal. This paper proposes a multi-objective approach to cope with the weight tuning problem for practitioners. A novel intelligent multi-objective evolutionary algorithm IMOEA is utilized to simultaneously edit compact reference and feature sets for nearest neighbor classification. Three comparison studies are designed to evaluate performance of the proposed approach. It is shown empirically that the IMOEA-designed classifiers have high classification accuracy and small sizes of reference and feature sets. Moreover, IMOEA can provide a set of good solutions for practitioners to choose from in a single run. The simulation results indicate that the IMOEA-based approach is an expedient method to design nearest neighbor classifiers, compared with an existing single-objective approach. (c) 2005 Elsevier Inc. All rights reserved.
Differential response of vacuolar proton pumps to osmotica
(2006)
Chiu, FS
;
Hsu, SH
;
Chen, JH
;
Hsiao, YY
;
Pan, YJ
The vacuole is a fundamental and dominant organelle and occupies a large part of the total cell volume in most mature plant cells. The higher-plant vacuole contains two types of proton-translocating pumps, H+-ATPase (EC 3.6.1.3) and H+-pyrophosphatase (EC 3.6.1.1), residing on the same membrane. These two enzymes generate roughly equal proton gradients across the vacuolar membrane for the secondary transport of ions and metabolites. However, the pumps respond differentially to stress in order to maintain critical functions of the vacuole. In this work, tonoplasts from etiolated mung bean seedlings ( Vigna radiata L.) were used to investigate the function of these two enzymes under high osmotic pressure. At high concentrations of sucrose or sorbitol, the light scattering and volume of isolated vesicles were progressively changed. Concomitantly, enzymatic activities, proton translocation, and coupling efficiencies of these two proton-pumping enzymes were inhibited to various extents under high osmotic pressure. No significant change in enzymatic activities of purified vacuolar H+-PPase and H+-ATPase under similar conditions was observed. We thus believe that the membrane structure is an important determinant for proper function of proton pumping systems of plant vacuoles. Furthermore, kinetic analysis shows different variation in apparent V-max but not in K-M values of vacuolar H+-PPase and H+-ATPase at high osmolarity of sucrose and sorbitol, respectively, suggesting probable alterations in substrate hydrolysis reactions but not substrate-binding affinity of the enzymes. A working model is proposed to interpret supplemental roles of vacuolar H+-PPase and H+-ATPase to maintain appropriate functions of plant tonoplasts.
Electrochemical characteristics of surface of titanium formed by electrolytic polishing and anodizing
(2005-08-01)
Chen, CC
;
Chen, JH
;
Chao, CG
;
Say, WC
;
材料科學與工程學系
A clear surface was polished using electrolytic polishing (EP). The mean roughness (Rz) of the polished surface was 1.966 nm, as measured by atomic force microscopy (AFM) over a 2 x 2 um(2) scan area. The various directions of the grains could be observed clearly following EP. The multiple beam interference effect generated various colors of the grains after anodic treatment at constant anodic voltage. A template with ordered nanochannel-array of anodic titanium oxide (ATO) was formed at 20 V. The template formed by self-assembly. The long-range ordered nanochannel had a thickness of 170 nm film, a pore size of 100 nm, an inter-pore distance of 120 nm, pore walls with a thickness of 25 nm, a pore density of 8 x 10(9) pores/cm(2), and a porosity of 68.2%, after anodizing for 90 s. When the applied voltage exceeded the breakdown voltage (90 V) of titania, the corrosion rate increased and the color of the titanium became as measured electrochemically by Tafel polarization and AC impedance methods, and observed by optical microscopy. (c) 2005 Springer Science + Business Media, Inc.
Enhancement of integrity of polysilicon oxide by using a combination of N2O nitridation and CMP process
(1999-05-01)
Lei, TF
;
Chen, JH
;
Wang, MF
;
Chao, TS
;
電子工程學系及電子研究所
This work prepares and demonstrates, for the first time, a high-quality polysilicon oxide, by combining N2O nitridation and Chemical Mechanical Polishing (CMP) process. Our results demonstrate that capacitors with this process have an improved Q(bd) (charge-to-breakdown) due to the planar surface and more concentrated nitrogen at the interface of polysilicon oxide.
FGS-based video streaming test bed for MPEG-21 universal multimedia access with digital item adaptation
(2003)
Wang, CN
;
Tsai, CY
;
Lin, HC
;
Chaung, HC
;
Lin, YC
It is a challenging problem to stream real-time video over heterogeneous networks with time-varying channel conditions and devices with different capabilities. In this paper, we present an FGS based unicast video streaming test bed, which is now being considered by the MPEG-4/21 committee as a reference test bed. The proposed system supports resource adaptation delivery of MPEG-21 DIA scheme which leads to a more strict evaluation methodology according to the MPEG committee specified common test conditions for scalable video coding. It provides easy control of media delivery with duplicable network conditions. To provide the best quality of service for each client, we propose relevant rate control, error protection, and transmission approaches in the content server, network interface, and clients, respectively.
Formation of dual-phase HfO2-HfxSi1-xO2 dielectric and its application in memory devices
(2005-07-01)
Wang, YQ
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Chen, JH
;
Yoo, WJ
;
Yeo, YC
;
Yeo, YC
In this paper, we studied the phase-separation phenomenon of Hf0.5Si0.5O2 film deposited on SiO2 or sandwiched by SiO2, by x-ray photoelectron spectroscopy and transmission electron microscopy. The Hf0.5Si0.5O2 film underwent phase separation to form a doublet-phase HfO2-HfxSi1-xO2 (x < 0.5) film, and was used as a trapping layer in a metal-blocking oxide-silicon nitride-tunnel oxide-silicon-type memory structure, where the dual-phase HfO2-HfxSi1-xO2 (DPHSO) film replaces the conventional silicon nitride (Si3N4) trapping layer. The charge storage properties of the DPHSO film were investigated and compared with HfO2 and Si3N4. It was found that for a given electric field applied to the tunnel oxide, the programming speed of memory devices using a DPHSO or HfO2 film as a trapping layer is faster than that using SiA. This indicates the higher electron-capture efficiency of the DPHSO and HfO2 films. In addition, the double-phase microstructure of the DPHSO film also provided better retention property than pure HfO2. (c) 2005 American Institute of Physics.
Holographic spatial walk-off polarizer and its application to a 4-port polarization-independent optical circulator
(2003-08-25)
Chen, JH
;
Su, DC
;
光電工程學系
;
Department of Photonics
Based on the coupled-wave theory, a holographic spatial walk-off polarizer (HSWP) is designed. This HSWP is a transmission-type phase volume holographic grating on a substrate and its optical recording geometry can be derived from Chen's corrected methodology with a desired reconstruction condition. A pair of fabricated HSWPs with the splitting angle of 60degrees is applied to assemble a new type of 4-port polarization-independent optical circulator. The operating principles and the characteristics of the proposed HSWP and the prototype optical circulator are discussed. (C) 2003 Optical Society of America.