Browsing by Issue Date, starting with "1997-04-20"

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Deposition of indium tin oxide films on polycarbonate substrates by radio-frequency magnetron sputtering
(1997-04-20)
Wu, WF
;
Chiou, BS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Indium tin oxide (ITO) films have been deposited onto polycarbonate (PC) substrates by radio frequency (rf) magnetron sputtering. The influence of the oxygen content during sputtering on the film morphology, and the electrical and optical properties of the films have been investigated. Both the refractive index and the extinction coefficient decrease with increasing oxygen content. In this study, the figures of merit T-10/R-sh of the films are higher than those for low-temperature sputtered films reported in the literature. (C) 1997 Elsevier Science S.A.
Cooperative behavior of RVB, flux phase, and antiferromagnetic states
(1997-04-20)
Chiueh, HL
;
Chuu, DS
;
電子物理學系
;
Department of Electrophysics
The coexistence of RVB, flux phase, and antiferromagnetic states for the t-J model is studied within the frame work of the mean-field theory by means of the slave-boson approach. Two simple relations among these three order parameters manifesting the cooperative behavior of these states are derived. A phase diagram separating the antiferromagnetic from the non-antiferromagnetic stale is obtained. Comparison with available previous work shows that our result agrees reasonably well. (C) 1997 Elsevier Science B.V.
Deposition of indium tin oxide films on polycarbonate substrates by radio-frequency magnetron sputtering
(1997-04-20)
Wu, WF
;
Chiou, BS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Indium tin oxide (ITO) films have been deposited onto polycarbonate (PC) substrates by radio frequency (rf) magnetron sputtering. The influence of the oxygen content during sputtering on the film morphology, and the electrical and optical properties of the films have been investigated. Both the refractive index and the extinction coefficient decrease with increasing oxygen content. In this study, the figures of merit T-10/R-sh of the films are higher than those for low-temperature sputtered films reported in the literature. (C) 1997 Elsevier Science S.A.
Effects of analyte-matrix interactions on supercritical fluid extraction efficiencies of polycyclic aromatic hydrocarbons
(1997-04-21)
Hsieh, YZ
;
Chang, AC
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
The effects of different variables for analyte-matrix interactions on supercritical fluid extraction (SFE) efficiencies of polycyclic aromatic hydrocarbons (PAHs) were investigated. The results indicated that the main factors for describing a matrix, e.g., the chemical properties of the matrix surface, surface area, and pore size, could significantly influence the analyte-matrix interactions. The polarizability of an analyte was demonstrated to be yet another significant factor for influencing analyte-matrix interactions. Either elevating the temperature or adding modifiers could also increase the SFE recoveries. The underlying mechanisms of these variables are discussed.
A novel one-pot conversion of tetraacetal tetraoxa-cages to aza-cages mediated by iodotrimethylsilane in acetonitrile
(1997-04-21)
Wu, HJ
;
Chern, JH
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
Treatment of the tetraacetal tetraoxa-cages 1a-f with excess of iodotrimethylsilane in acetonitrile at 25 degrees C gave the novel tetraacetal trioxamonoaza-cages 2a-f in 75-80% yields respectively, a novel one-pot conversion of era-cages to ata-cages. (C) 1997 Elsevier Science Ltd.
A novel one-pot conversion of tetraacetal tetraoxa-cages to aza-cages mediated by iodotrimethylsilane in acetonitrile
(1997-04-21)
Wu, HJ
;
Chern, JH
;
應用化學系
;
Department of Applied Chemistry
Treatment of the tetraacetal tetraoxa-cages 1a-f with excess of iodotrimethylsilane in acetonitrile at 25 degrees C gave the novel tetraacetal trioxamonoaza-cages 2a-f in 75-80% yields respectively, a novel one-pot conversion of era-cages to ata-cages. (C) 1997 Elsevier Science Ltd.
Determination of preservatives in food products by cyclodextrin-modified capillary electrophoresis with multiwavelength detection
(1997-04-25)
Kuo, KL
;
Hsieh, YZ
;
應用化學系
;
Department of Applied Chemistry
A high-performance capillary electrophoretic method with multiwavelength detection was developed to analyze frequently used preservatives. The effects of alpha-cyclodextrin and beta-cyclodextrin on migration behaviours of nine preservatives were investigated. The preservatives were successfully separated within 9 min using a borax-NaOH buffer (pH 10.0) modified with 2 mM alpha-cyclodextrin. In optimized separation conditions, the reproducibilities of the migration times of the preservatives were satisfactory (R.S.D. values <0.99%). The correlation coefficients of the linear calibration graphs for the preservatives, ranging between 5 and 500 mu g ml(-1), exceeded 0.991. By employing this reliable capillary electrophoresis method, preservatives in three different food products were determined.
Blind identification and deconvolution algorithms using higher-order cumulants
(1997-05-01)
Ueng, FB
;
Su, YT
;
電信工程研究所
;
Institute of Communications Engineering
The use of second-order statistics in identification or deconvolution incurs error due to additive Gaussian noise. In contrast, higher-order statistics (HOS) are insensitive to Gaussian perturbation and can be used to characterize nonminimum phase (NMP) systems. In this paper we propose batch, recursive and adaptive form algorithms based on third- and fourth-order cumulants to solve the identification and deconvolution problems. A new order determination procedure is also presented. Simulation results demonstrate that our algorithms do have superior performance when compared with existing algorithms.
Isometric muscle strength of Chinese young males in Taiwan
(1997-05-01)
Chuang, MC
;
You, ML
;
Cai, DC
;
Chen, CC
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應用藝術研究所
This paper represents the results of an anthropometric measurement of the isometric muscle strength of Chinese young males in Taiwan aged from 16 to 20 years. The study uses a sample of 120 male students and measures four types of muscle strength: (1) right arm strength in exerting pull, push, adduction, abduction, lift, and press directions with five elbow angles (60, 90, 120, 150 and 180 degrees) in seated posture; (2) grip strength of both hands; (3) backlift strength; and (4) chest expanding strength. The obtained data are analysed and listed. Comparisons are made between the results of this study and those from domestic and foreign studies available in the literature. Tn general, their pattern is similar, but values obtained in this study are relatively smaller than those obtained in western countries.
Scattering analyses of asymmetric conductor-backed CPW open-end discontinuity problem
(1997-05-01)
Liu, SP
;
Tzuang, CKC
;
交大名義發表
;
電信工程研究所
;
National Chiao Tung University
The space-domain integral equation method using the generalized scattering matrix description of microwave passive circuits is employed to investigate the mode conversion of a CBCPW open-end discontinuity with unequal side plane widths. The conversion into two additional dominant modes, the c-mode-like mode and the pi-mode-like mode, and into the transmitted microstrip mode from an incident CPW mode is studied against side plane width, degree of asymmetry, substrate thickness, and frequency. Theoretical results are in excellent agreement with experimental ones.
The role of resist for ultrathin gate oxide degradation during O-2 plasma ashing
(1997-05-01)
Chien, CH
;
Chang, CY
;
Lin, HC
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Chiou, SG
;
Huang, TY
During ashing process, resist has been intuitively regarded as a protection layer and deliberately removed in previous studies by wet process prior to plasma exposure in an effort to amplify the damage effect, Recently, we found instead that resist does not simply act as a protection layer, This newly observed phenomenon cannot be explained by the well-known electron shading effect which should not affect the area-intensive antenna structure used in our study, In this letter, we hypothesize that this resist-related charging damage is determined by the plasma potential adjustment difference between those devices with and without resist overlayer, The experimental results show a good correlation with our explanation, To be specific, severe antenna area ratio (ARR) dependent degradation of thin gate oxide is induced during the initial ashing stage while the resist is still on the electrodes, not during the overashing period.
Atomic-level investigation of the growth of Si/Ge by ultrahigh vacuum chemical vapor deposition
(1997-05-01)
Lin, DS
;
Miller, T
;
Chiang, TC
;
物理研究所
;
Institute of Physics
Si and Ge films can be prepared under ultrahigh vacuum conditions by chemical vapor deposition using disilane and digermane as source gases. These gases offer a high sticking probability, and are suitable for atomic layer epitaxy. Using synchrotron radiation photoemission spectroscopy and scanning tunneling microscopy, we have examined the surface processes associated with the heteroepitaxial growth of Ge/Si. The measured surface-induced shifts and chemical shifts of the Si 2p and Ge 3d core levels allow us to identify the surface species and to determine the surface chemical composition, and this information is correlated with the atomic features observed by scanning tunneling microscopy. Issues related to precursor dissociation, attachment to dangling bonds, diffusion, surface segregation, growth morphology, and pyrolytic reaction pathways will be discussed. (C) 1997 American Vacuum Society.
Intrinsic thermal stability and quenching recovery of thin-film superconductors with thermal boundary resistance
(1997-05-01)
Wu, JP
;
Chu, HS
;
機械工程學系
;
Department of Mechanical Engineering
The stability behaviour of a thin-film superconductor under a localized release of thermal disturbance is investigated. Two-dimensional conjugate film/substrate conduction equation with anisotropic thermal conductivity of the film, and Joule heat are employed to investigate effects of substrate and thermal properties on the intrinsic stability and quenching recovery. To consider the thermal boundary resistance between film and substrate, an interfacial-layer model (ILM) with very low diffusivity and an acoustic mismatch model (AMM) are employed. Results show that the thermal boundary resistance influences strongly the intrinsic stability. Thermal boundary resistance increases intrinsic stability if the thermal conductivity of the substrate or the disturbance energy is large. Higher Riot numbers and thermal conductivity ratios of film to substrate in longitudinal direction influence stability favorably. We demonstrate also that operation of a film/substrate system, such as YBCO/MgO, is either intrinsically stable or irrecoverably unstable.
Design of a resonant-cavity-enhanced photodetector for high-speed applications
(1997-05-01)
Tung, HH
;
Lee, CP
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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 present a theoretical study of the effects of light field distribution on the frequency response of a resonant-cavity-enhanced p-i-n photodetector, Taking advantage of the flexibility of cavity design, one can tailor the light field distribution in the absorption region, Because of the difference in velocities of the carriers, the speed performances of the detector depend on the field distribution and the cavity design, The results of our work indicate that when the maximum of light field intensity happens near the p(+) edge of the depletion layer, the device shows the best speed performance, The frequency response, the impulse response, and the step response have been calculated for different structures to demonstrate the importance of the field distribution.
An Authentication Protocol Without Trusted Third Party
(1997-05-01)
Shieh, Shiuh-Pyng
;
Yang, Wen-Her
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Sun, Hun-Min
;
資訊工程學系
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Department of Computer Science
A secure authentication protocol which supports both the privacy of messages and the authenticity of communicating parties is proposed. The trusted third party (key information center) is not needed once the secure network system is set up. Mutual authentication and key distribution can be achieved with two messages merely between two parties involved.
Using knowledge-based techniques on loop parallelization for parallelizing compilers
(1997-05-01)
Yang, CT
;
Tseng, SS
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Chuang, CD
;
Shih, WC
;
資訊工程學系
In this paper we propose a knowledge-based approach for solving data dependence testing and loop scheduling problems. A rule-based system, called the K-Test, is developed by repertory grid and attribute ording table to construct the knowledge base. The K-Test chooses an appropriate testing algorithm according to some features of the input program by using knowledge-based techniques, and then applies the resulting test to detect data dependences for loop parallelization. Another rule-based system, called the KPLS, is also proposed to be able to choose an appropriate scheduling by inferring some features of loops and assign parallel loops on multiprocessors for achieving high speedup. The experimental results show that the graceful speedup obtained by our compiler is obvious.
Fully normalized spherical cap harmonics: Application to the analysis of sea-level data from TOPEX/POSEIDON and ERS-1
(1997-05-01)
Hwang, CW
;
Chen, SK
;
交大名義發表
;
土木工程學系
;
National Chiao Tung University
We introduce two sets of fully normalized harmonics for the spectral analysis of functions defined on a spherical cap. The harmonics are the products of Fourier functions and the fully normalized associated Legendre functions of non-integer degree. Using Sturm-Liouville theory for boundary-value problems, we present two convenient and stable formulae for computing the zeros of the associated Legendre functions that form two sets of orthogonal functions. Formulae for the stable numerical evaluation of the fully normalized associated Legendre functions of non-integer degree that avoid the gamma function are also derived. The result from the expansions of sealevel anomaly from altimetry into Set 2 fully normalized cap harmonics shows fast convergence of the series, and the degree variances decay rapidly without aliasing effects. The zero-degree coefficients (Set 2) of sea-level anomaly from TOPEX/POSEIDON (T/P) and ERS-1 indicate an El Nino event during 1993 January-1993 July, and a La Nina event during 1993 November-1994 July, although the ERS-1 result is less obvious. Ocean circulations over the South China Sea and the Kuroshio area are clearly identified with the low-degree expansions of sea-surface topography (SST) from T/P and ERS-1. A cold-core eddy of 4 degrees in diameter centred at 17.5 degrees N, 118 degrees E was detected with the expansion of SST from T/P cycle 47, and a property of the cap harmonics is used to compute this eddy's kinetic energy. The kinetic energy is at a low in winter and high in summer, and its variation seems to be periodic with an amplitude of 0.4 m(2) s(-2).
Refractive-index measurement based on the effects of total internal reflection and the uses of heterodyne interferometry
(1997-05-01)
Chiu, MH
;
Lee, JY
;
Su, DC
;
光電工程研究所
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Institute of EO Enginerring
A new method for measuring the refractive index is presented, First, the phase difference between s and p polarizations that is due to the total internal reflection is measured by heterodyne interferometry. Then, substituting this phase difference into the Fresnel equations, we can obtain the refractive index of the test medium. (C) 1997 Optical Society of America.
A synthesis of 6-myoporol
(1997-05-01)
Ho, TL
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Chein, RJ
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交大名義發表
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應用化學系
;
National Chiao Tung University
An approach to (+/-)-6-myoporol (1) featured stereocontrol by equilibration of 2,6-disubstituted cyclohexanones to mainly the cis isomer. The synthesis was completed by reaction of a lactone intermediate with 3-lithiofuran, Mitsunobu reaction, and hydrolysis.
Design of a permanent/electromagnetic magnetic bearing-controlled rotor system
(1997-05-01)
Fan, YH
;
Lee, AC
;
Hsiao, FZ
;
機械工程學系
;
Department of Mechanical Engineering
This study proposes design procedures for the permanent-magnet-biased magnetic bearings (PEMBs) in rotor systems. Many aspects of designing magnetic bearings are discussed, e.g. the selection of a permanent magnet material, dimensions of electromagnets and permanent magnets, gap length, load capacity and maximum Ampere-turns. Linearization and DC current driver are the two constraints for determining feasible designs. According to an analytical model with a rigid body assumption for the rotor-bearing system, a decentralized output feedback control algorithm is employed to control this inherently unstable magnetic suspension rotor system. Experimental results indicate that the controlled rotor performs well at rotor speeds up to 12,000 rpm. (C) 1997 Published by Elsevier Science Ltd.