Browsing by Issue Date, starting with "1995-10-01"

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ALGORITHMS FOR THE RURAL POSTMAN PROBLEM
(1995-10-01)
PEARN, WL
;
WU, TC
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
The rural postman problem (RPP) is a practical extension of the well-known Chinese postman problem (CPP), in which a subset of the edges (streets) from the road network are required to be traversed at a minimal cost. The RPP is NP-complete if this subset does not form a weakly connected network. Therefore, it is unlikely that polynomial-time bounded algorithms exist for the problem. In this paper, we review the existing heuristic solution procedures, then present two new algorithms to solve the problem near-optimally. Computational results showed that the proposed new algorithms significantly outperformed the existing solution procedures.
SUB-POISSON PHOTOELECTRON STATISTICS IN SATURATED LIGHT-ABSORPTION
(1995-10-01)
MENG, HF
;
物理研究所
;
Institute of Physics
We show that sub-Poisson photoelectrons can result from the finite relaxation time of the fundamental photoelectron-emitting entities, which could be individual atoms, or valence-band electrons, etc., depending on the type of the detectors. After identifying the precise quantum-mechanical criterion for a light without the intrinsic antibunching property, it is demonstrated that the variance to mean ratio of photoelectron counts within a fixed time period can be reduced to as small as 1/2, even for such light. The condition for strong fluctuation reduction is found to be the saturation of light absorption. Semiconductor photodetectors are considered in relative details, and their photoelectron statistics are expressed in terms of the intrinsic material parameters.
EFFECTS OF DRY-ETCHING DAMAGE REMOVAL ON LOW-TEMPERATURE SILICON SELECTIVE EPITAXIAL-GROWTH
(1995-10-01)
TSENG, HC
;
CHANG, CY
;
PAN, FM
;
CHEN, LP
;
電子工程學系及電子研究所
The epitaxial silicon layer selectively grown on the reactive ion etched (RIE) silicon substrate using CF4, CHF3 and Ar etching gases has been studied. Defects and contaminants induced by the RIE process result in a rough epilayer, and degrade the current-voltage (I-V) characteristics. An interfacial carbide layer is present between the epilayer and the RIE treated substrate. Using an efficient and convenient after-etching treatment with a CF4/O-2 low-energy plasma, we obtain a clean Si surface in the patterned oxide windows for selective epitaxial growth, and the electrical characteristics are significantly improved. (C) 1995 American Institute of Physics.
PRECLASSIFICATION OF HANDWRITTEN CHINESE CHARACTERS BASED ON BASIC STROKE SUBSTRUCTURES
(1995-10-01)
CHENG, RH
;
LEE, CW
;
CHEN, Z
;
資訊科學與工程研究所
;
Institute of Computer Science and Engineering
A method for preclassification of handwritten Chinese characters is presented. A set of basic stroke substructures is defined using the consistent stroke connection relations. A knowledge guided recognition process is employed to identify the types of the extracted basic stroke substructures found in a handwritten character. Then a 1-D character coding scheme is given to represent the character and the code can be also used for character preclassification.
A MODEL FOR PREDICTING PERFORMANCE OF AN ANNULAR DENUDER SYSTEM
(1995-10-01)
LU, CY
;
BAI, HL
;
LIN, YM
;
環境工程研究所
;
Institute of Environmental Engineering
A mathematical model for simultaneous gas diffusion, aerosol diffusion and evaporation is presented to predict performance of the annular denuder system. Approximating the aerosol size distribution by a lognormal function and using the statistical method of moment, the evolution of the three aerosol moments and the mass balance equations for the two associated gases in the annular denuder system are obtained. The governing equations were cast into dimensionless form and the performance of the model was validated by the existing data available in the literature. The effects of governing dimensionless groups on the model performance were evaluated in the sensitivity analysis. The model was then applied for sampling nitric acid gas using a typical range of atmospheric aerosol and gas properties to derive the performance equation of the annular denuder system. The methodologies presented herein are helpful in providing design and operational criteria of the annular denuder system for a real sampling of atmospheric reactive gases that minimizes measurement artifacts.
A NOVEL PLANARIZATION OF TRENCH ISOLATION USING POLYSILICON REFILL AND ETCHBACK OF CHEMICAL-MECHANICAL POLISH
(1995-10-01)
CHENG, JY
;
LEI, TF
;
CHAO, TS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The planarization of trench isolation refilled by deposition oi polysilicon was investigated. Results show that the planarization by RIE etching has poor surface planarity. On the other hand, an excellent surface planarity can be achieved by the CMP process resulting from the high etching selectivity of polysilicon to nitride. This simple process provides a very promising candidate for trench isolation.
A NOVEL PLANARIZATION OF TRENCH ISOLATION USING POLYSILICON REFILL AND ETCHBACK OF CHEMICAL-MECHANICAL POLISH
(1995-10-01)
CHENG, JY
;
LEI, TF
;
CHAO, TS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The planarization of trench isolation refilled by deposition oi polysilicon was investigated. Results show that the planarization by RIE etching has poor surface planarity. On the other hand, an excellent surface planarity can be achieved by the CMP process resulting from the high etching selectivity of polysilicon to nitride. This simple process provides a very promising candidate for trench isolation.
CONVERGENCE-RATES OF ITERATIVE SOLUTIONS OF ALGEBRAIC MATRIX RICCATI-EQUATIONS
(1995-10-01)
JUANG, J
;
NELSON, P
;
應用數學系
;
Department of Applied Mathematics
We consider the iterative solutions of a certain class of algebraic matrix Riccati equations with two parameters, c(0 less than or equal to c less than or equal to 1) and alpha(0 less than or equal to alpha less than or equal to 1). Here c denotes the fraction of scattering per collision and alpha is an angular shift. Equations of this class are induced via invariant imbedding and the shifted Gauss-Lengendre quadrature formula from a ''simple transport model.'' The purpose of this paper is to describe the effects of the parameters c, alpha, and N (the dimension of the matrix) on the convergence rates of the iterative solutions. We also compare the convergence rates of those iterative methods.
CLUSTERING APPROACH TO GROUPING OBJECTS IN MESSAGE-PASSING SYSTEMS
(1995-10-01)
CHANG, WT
;
TSENG, CC
;
資訊工程學系
;
Department of Computer Science
Grouping related objects into processing nodes is one of the cost-effective solutions in distributed OOP. The authors propose a hierarchical clustering grouping strategy to minimize the cost of invocations on a given class hierarchy in a distributed manner.
LASER-DIODE-BASED OPTOELECTRONIC SUBHARMONIC PHASE-LOCKED LOOP
(1995-10-01)
LIN, GR
;
YANG, CR
;
PAN, CL
;
交大名義發表
;
光電工程學系
An optoelectronic technique for synthesis of frequency-versatile electrical signals phase-locked to the optical clock is proposed. The key component is an integrated-optic modulator (IOM) operated in the nonlinear regime. With a photodetctor, the IOM functions as an optoelectronic subharmonic mixer for intermixing microwave signals that are subharmonics of the optical clock, As a first demonstration, phase-locked subharmonics and fractional harmonics of the optical clock at f(o) = 500 MHz, with frequency equal to f(o)/n or (m/n)f(o), where n = 2,3,4... and m/n = 2/5,2/3,4/3,3/2 and 5/3 etc;, are generated and characterized.
THE REVERSIBILITY OF 6 GEOMETRIC COLOR SPACES
(1995-10-01)
SHIH, TY
;
交大名義發表
;
土木工程學系
;
National Chiao Tung University
;
Department of Civil Engineering
Color coordinate systems provide a way to address, to describe, and to manipulate colors. in the field of image processing and computer graphics, several color models in common use include RGB, HVC, HSV HLS, and ISH. In this study, the reversibility of several color coordinate systems and their numerical characteristics are studied. All these models are classified as user-oriented and related to the perceptual color space.
CONTROLLING FLUORINE CONCENTRATION AND THERMAL ANNEALING EFFECT ON LIQUID-PHASE DEPOSITED SIO2-XFX FILMS
(1995-10-01)
YEH, CF
;
CHEN, CL
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Silicon oxide (SiO2-xFx) with fluorine naturally incorporated can be prepared by the liquid-phase deposition (LPD) method at 15 degrees C. The fluorine is uniformly distributed in the bulk of the LPD oxide. The fluorine incorporation as well as the qualitative properties can be accurately controlled by varying the amount of H2O added. A high temperature process has considerable effect on the low temperature fluorinated oxide. FTIR and XPS spectra show that Si-F and SiO-H bonds can restructure with densification at higher thermal annealing temperature, and that restructuring is a function of temperature. Film densification with increasing temperature is also discussed in terms of Si-O-Si bond angle and Si-Si bond length.
FORMATION OF TETRAACETAL OXA-CAGES AND CONVEX OXA-CAGES ON OZONOLYSIS OF BICYCLO[2.2.2]OCTENES
(1995-10-01)
LIN, CC
;
WU, HJ
;
應用化學系
;
Department of Applied Chemistry
Tetraacetal oxa-cage compounds 5a and 5b and convex era-cage compounds 7a and 8a are synthesized in a short sequence. Ozonolysis of endo adducts 2a and 2b in dichloromethane at -78 degrees C followed by reduction with dimethylsulfide gave tetraacetal era-cages 5a and 5b in 35 % yields respectively. Ozonolysis of 2a in dichloromethane at -78 degrees C followed by treatment with triethylamine gave the convex era-cage 7a in 34% yield. These results support an acid-base proton transfer between the final ozonides and the base. The reasons that these era-cage compounds formed in low yields are discussed. The synthesis of tetraacetal oxa-cage 14, possessing aromatic substitutents directly on the skeleton of the era-cage, is accomplished.
DEGRADATION PHENOMENA DUE TO IMPULSE-CURRENT IN ZINC-OXIDE VARISTORS
(1995-10-01)
BAI, SN
;
TSENG, TY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The relationship between the electrical characteristics of the ZnO varistors and applied current impulse is investigated in this study, The degradation phenomena of the ZnO varistors due to current impulse are studied by I-V and ac measurements, The influence of various numbers of applied surge on the I-V behaviors, V-0.1mA and leakage current, is attributed to the asymmetrical deformation of the grain-boundary barriers, As the applied impulses increase, the changes observed in the properties of deep bulk trap and conduction mechanism are attributed to the alternation of defect structure and model of conduction.
NOVEL 2-DIMENSIONAL TRANSMISSION-LINE COLLECTION SYSTEMS FOR PHOTOVOLTAIC POWER
(1995-10-01)
KUO, MY
;
KUO, CC
;
KUO, MS
;
交大名義發表
;
電控工程研究所
Innovative two-dimensional transmission-line systems for collecting distributed photovoltaic power are presented in this paper. Based on transmission-line theory and controlling the phase of a.c. sources, the net power of the proposed transmission-line type network can flow towards the target load. The validity of the proposed system is confirmed by mathematical analysis and simulated results. This paper makes a contribution to the concept of networks for the collection of renewable energy.
MICROCRYSTALLINE SIC FILMS GROWN BY ELECTRON-CYCLOTRON-RESONANCE CHEMICAL-VAPOR-DEPOSITION AT LOW-TEMPERATURES
(1995-10-01)
CHENG, KL
;
CHENG, HC
;
LIU, CC
;
LEE, C
;
YEW, TR
The characteristics of microcrystalline silicon carbide (mu c-SiC) films deposited using an electron cyclotron resonance chemical vapor deposition system at low temperatures have been investigated. The effect of microwave (MW) power on the SiC crystallinity is studied. According to the results of Fourier transform infrared absorption spectra, plan-view transmission electron microscopy, and the plasmon loss peaks in X-ray photoelectron spectroscopy, Si-C bonds form when the MW power is above 500 W for deposition at 500 degrees C. The SiC crystallinity improves monotonically with MW power. The amount of incorporated carbon atoms in the grown films increases with MW power up to the concentration of 50% at 1500 W. The dependence of the surface morphology and the mean roughness of the films on MW power is examined using the contact mode atomic force microscopy.
RAMAN-SCATTERING OF SE-DOPED GALLIUM NITRIDE FILMS
(1995-10-01)
KUO, HR
;
FENG, MS
;
GUO, JD
;
LEE, MC
;
材料科學與工程學系
Raman spectra of Se-doped gallium nitride films have been measured for the first time with good resolution and a wide range of excitation wavelengths. The signals from both buffer layer and epilayer are identified unambiguously. We have observed not only the resonant scattering related to the transition below the band gap but also the phonon-plasmon coupling due to the doping effect. The carrier concentration obtained from lineshape fitting is consistent with that from Hall measurements. By comparing the Raman shifts with those of other nitrides and gallium compounds, we found that most of them are almost linearly proportional to the square root of reciprocal masses. The bonding strengths are thus inferred from the slopes.
EFFECTS OF DRY-ETCHING DAMAGE REMOVAL ON LOW-TEMPERATURE SILICON SELECTIVE EPITAXIAL-GROWTH
(1995-10-01)
TSENG, HC
;
CHANG, CY
;
PAN, FM
;
CHEN, LP
;
電子工程學系及電子研究所
The epitaxial silicon layer selectively grown on the reactive ion etched (RIE) silicon substrate using CF4, CHF3 and Ar etching gases has been studied. Defects and contaminants induced by the RIE process result in a rough epilayer, and degrade the current-voltage (I-V) characteristics. An interfacial carbide layer is present between the epilayer and the RIE treated substrate. Using an efficient and convenient after-etching treatment with a CF4/O-2 low-energy plasma, we obtain a clean Si surface in the patterned oxide windows for selective epitaxial growth, and the electrical characteristics are significantly improved. (C) 1995 American Institute of Physics.
DEGRADATION PHENOMENA DUE TO IMPULSE-CURRENT IN ZINC-OXIDE VARISTORS
(1995-10-01)
BAI, SN
;
TSENG, TY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The relationship between the electrical characteristics of the ZnO varistors and applied current impulse is investigated in this study, The degradation phenomena of the ZnO varistors due to current impulse are studied by I-V and ac measurements, The influence of various numbers of applied surge on the I-V behaviors, V-0.1mA and leakage current, is attributed to the asymmetrical deformation of the grain-boundary barriers, As the applied impulses increase, the changes observed in the properties of deep bulk trap and conduction mechanism are attributed to the alternation of defect structure and model of conduction.
SYNTHESIS OF FLUORINATED NAPHTHYLPHENYLACETYLENIC AND NAPHTHYLPHENYLDIACETYLENIC LIQUID-CRYSTALS
(1995-10-01)
HSU, CS
;
TSAY, KT
;
CHANG, AC
;
WANG, SR
;
WU, ST
Four series of fluorinated tolanes, naphthylphenylacetylenes and naphthylphenyldiacetylenes were prepared and characterized. Most of the fluorinated tolanes exhibit no mesomorphic behaviour. However, most of the fluorinated naphthylphenylacetylenes and naphthylphenyldiacetylenes form enantiotropic nematic phases. The dielectric anisotropy and birefringence of some selected compounds were measured by a guest-host method. All of those studied show relatively high dielectric anisotropy and birefringence.