Browsing by Issue Date, starting with "1995-07-01"

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ON A SATELLITE COVERAGE PROBLEM
(1995-07-01)
CHI, DT
;
SU, YT
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電信工程研究所
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電子與資訊研究中心
;
Institute of Communications Engineering
The earth coverage area for a satellite in an Earth synchronous orbit with a non-zero inclination angle is a function of the time of day. Locating the area where an Earth terminal can establish a link with a geosynchronous satellite at a certain period of the day is of great concern to system designers: A special case of much interest is when the time period of satellite coverage is 24 h. Two simple and rapid algorithms for locating 24 h satellite coverage areas are presented. One of the proposed algorithms can also be applied to determine other airborne antenna coverage problems.
CHROMIC-ACID RECOVERY FROM CHROME PLATING RINSE WATER BY ION-EXCHANGE
(1995-07-01)
TAN, H
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交大名義發表
;
應用化學系
;
National Chiao Tung University
;
Department of Applied Chemistry
The regeneration of an anion bed saturated with dichromate ions by treatment with NaOH solution was studied in connection with the treatment of chrome plating rinse water by ion exchange. Column experiments were conducted to obtain an Cr(VI) elution curve and OH- breakthrough curve. The parametric effects of bed height, NaOH feed concentrations, and flow rate on the performance of regeneration were investigated. It was found that for a bed height of 70 cm and NaOH feed concentration of 1.5 to 2 mol/L with a flow rate of 100-150 mL/hr, up to a maximum concentration of 100 g/L of CrO3 could be obtained. Under the above operating conditions, the regenerant consumption is about 1.65 mole of OH- per mole of Cr(VI) recovered and the resin utilization is about 80%. An attempt is made to employ a simple analytic equation to correlate the OH- breakthrough and Cr(VI) elution data. The results of this work may be useful in the design and operation of systems for recovery and reuse of chromic acid by ion exchange in the chrome electroplating process.
DESIGN OF AN EFFICIENT DATA-DRIVEN PIPELINED COMPUTER ARCHITECTURE
(1995-07-01)
LIN, CZ
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TSENG, CC
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CHI, KH
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交大名義發表
;
資訊工程學系
The combination of dataflow and von Neumann execution models is a recent trend in the design of high performance computers. In this paper, a data-driven hybrid computer architecture is presented. Instead of a program counter, the principle of dynamic data-driven execution is used to control the execution of instructions in a von Neumann-style pipeline architecture. One of the operands of each dyadic instruction is explictly stored in memory, and the memory locations of the stored operands are used as tags. Matching is accomplished by simply checking a present flag and no special matching unit is required. No bubbles will occur in the pipe if sufficient parallelism exists in the program. Experimental results show that the proposed architecture outperforms two previously proposed architectures.
A DOUBLE METAL STRUCTURE PT/AL/N-INP DIODE
(1995-07-01)
HUANG, WC
;
LEI, TF
;
LEE, CL
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
POLYURETHANES SYNTHESIZED FROM POLYESTER POLYOLS DERIVED FROM PET WASTE .1. SYNTHESIS AND REACTION-KINETICS
(1995-07-01)
LEE, SC
;
SZE, YW
;
LIN, CC
;
交大名義發表
;
應用化學系
AN OPTIMAL ALGORITHM FOR FINDING THE MOST VITAL EDGE WITH RESPECT TO SKT RELIABILITY IN BSP DIGRAPHS
(1995-07-01)
WANG, PF
;
LEU, SC
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HSU, LH
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資訊工程學系
;
Department of Computer Science
The SKT reliability is the probability that a source can send communication to a specified set of terminals K in V in a probabilistic digraph D = (V, E). ''The most vital edge'' is the edge whose deletion yields the largest decrease in the SKT reliability. A digraph is a basically-series-parallel(BSP) directed graph if its underlying undirected graph is series-parallel. In this paper, we propose a tree-like structure and present an optimal algorithm with linear time complexity for finding the most vital edge with respect to SKT reliability in BSP digraphs.
ORIENTATION DEPENDENCE OF COHERENT HOLE OSCILLATIONS IN GAAS/ALGAAS COUPLED QUANTUM-WELLS
(1995-07-01)
CHANG, CY
;
LU, MF
;
CHEN, PA
;
JUANG, C
;
電控工程研究所
Coherent hole tunneling dynamics in GaAs/AlGaAs coupled quantum wells (CQWs) based on (100)- and (111)-oriented GaAs substrates are investigated. The tunneling probability of the hole wave packet for a heavy-hole to heavy-hole (HH-HH) band and a light-hole to Light-hole (LH-LH) band is described based on the results of a time-dependent analysis. It is demonstrated that the CQW HH-HH oscillation frequency on (100) substrates is larger than that on (111) substrates due to a significantly lighter in-plane effective mass. However, the LH-LH spatial tunneling oscillation frequency on (100) substrates is smaller than that on (111) substrates.
Lyapunov-based quantitative analysis of robust stability
(1995-07-01)
Chen, HG
;
Han, KW
;
電控工程研究所
;
Institute of Electrical and Control Engineering
The robust stability of control systems with perturbation is considered. Using Lyapunov functions, quantitative bounds on the perturbation ave obtained such that the systems remain stable. Foul classes of perturbations are treated and four measures of robust stability are proposed: the nondelay unstructured, delayed unstructured, nondelay structured and delayed structured measures. Examples are given, and comparisons with the results given in current literature are made.
LOW-TEMPERATURE PROCESSED MOSFETS WITH LIQUID-PHASE DEPOSITED SIO2-XFX AS GATE INSULATOR
(1995-07-01)
YEH, CF
;
LIN, SS
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HONG, TY
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Device performances of MOSFET's with SiO2-xFx gate oxides prepared by an extremely low-temperature (15 degrees C) liquid phase deposition (LPD) method were investigated. The electrical characteristics, including threshold voltage of 2.1 V, peak effective mobility (mu(eff)) of 525 cm(2)V . s, and subthreshold suing of 134 mV/decade, show the devices exhibit comparable performance to other low-temperature processed MOSFET's. This demonstrates that LPD SiO2-xFx can be a suitable candidate for future gate insulators in low-temperature processed MOSFET's.
倉庫與名字
(1995-07-01)
管管
BACK-GATING EFFECTS ON THE GA0.1IN0.8P/INP/INGAAS HIGH-ELECTRON-MOBILITY TRANSISTOR
(1995-07-01)
LIN, KC
;
CHANG, CY
;
WU, CC
;
CHEN, HD
;
CHEN, PA
Pseudomorphic GaInP/InP/InGaAs high electron mobility transistors (HEMT) with improved Schottky contacts and excellent electrical characteristics are grown by low-pressure metal-organic chemical vapor deposition (LP-MOCVD) on the InP substrate. These HEMTs with 1.71 mu m gate length have an average extrinsic transconductance of 225 mS/mm. The back-gating effects of this device structure are investigated for the first time in this structure. Both positive and negative bias are applied to the ohmic and Schottky back-gate contacts of these devices. The positive back-gate bias has no effect on the drain current or the output transconductances of these devices. The effect of the negative back-gate bias is very similar to that when negative bias is applied on the gate of these HEMTs.
ATTENUATION OF THE PARASITIC MODES IN A SHIELDED MICROSTRIP LINE BY COATING RESISTIVE FILMS ON THE SUBSTRATE
(1995-07-01)
CHOU, YH
;
CHUNG, SJ
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交大名義發表
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傳播研究所
;
National Chiao Tung University
In this paper, propagation characteristics of even-symmetric hybrid modes in a waveguide-shielded microstrip line with the presence of the resistive films affixed to the two sides of the center strip is investigated. The method of lines with modifications concerning the inhomogeneity of the surface between the air and substrate layers is uded for analysis. After a validity check of the analysis by considering two special structures, i.e., a microstrip line (R(m) = infinity) and a coplanar waveguide (R(m) = 0), the resistance R(m) and the width W-m of the film are varied to see the influence on the propagation and attenuation constants of the dominant mode as well as the higher-order (parasitic) modes. Optimal combinations of the resistance and the width are found so that the resistive film has the largest attenuating effect on the higher-order modes but has no ingterference with the dominant one.
COMPLEMENTARY-SCR ESD PROTECTION CIRCUIT WITH INTERDIGITATED FINGER-TYPE LAYOUT FOR INPUT PADS OF SUBMICRON CMOS ICS
(1995-07-01)
KER, MD
;
WU, CY
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new ESD protection circuit with complementary SCR structures and junction diodes is proposed, This complementary-SCR ESD protection circuit with interdigitated finger-type layout has been successfully fabricated and verified in a 0.6-mu m CMOS SRAM technology with LDD process, The proposed ESD protection circuit can be free of VDD-to-VSS latchup issue under 5-V VDD operation by means of base-emitter shorting method, To compensate the degradation on latching capability of lateral SCR devices in the ESD protection circuit caused by base-emitter shorting method, the p-well to p-well spacing of lateral BJT's in the lateral SCR devices is reduced to lower its ESD-trigger voltage and to enhance turn-on speed of positive-feedback regeneration in the lateral SCR devices. This ESD protection circuit can perform high ESD failure threshold in a small layout area, so it is very suitable for submicron CMOS VLSI/ULSI's in high-pin-count or high-density applications.
TIW(N) AS DIFFUSION-BARRIERS BETWEEN CU AND SI
(1995-07-01)
CHIOU, JC
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JUANG, KC
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CHEN, MC
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
TiW(N) and aw are employed as diffusion barriers in the Cu/barrier/Si system. The thermal stability of Cu/TiW(N) and Cu/TiW contacted p(+)n junction diodes was investigated with respect to metallurgical reaction and electrical characteristics. The as-deposited TiW film formed body-centered cubic (bcc) structure, while the TiW(N) film formed face-centered cubic (fcc) structure. The Cu/TiW(600 Angstrom)/Si structure remains intact up to 750 degrees C 30 s rapid thermal anneal (RTA) in N-2 ambient; at 775 degrees C the Cu diffuses through the TiW layer to form Cu,Si with an overlayer of Ti-W-Si on the surface. The Cu/TiW(N)(600 Angstrom)/Si system is metallurgically stable up to 1000 degrees C 30 s RTA in N-2 ambient. The Cu/TiW(600 Angstrom)/p(+)n junction diodes were able to withstand the RTA annealing up to 675 degrees C without losing the device integrity; however, the devices' characteristics are completely destroy at temperatures above 775 degrees C inconsistent with the occurrence of dramatic metallurgical reaction. The Cu/TiW(N)(600 Angstrom)/p(+)n junction diodes were able to withstand the RTA treatment up to 650 degrees C without electrical characteristic degradation; and the devices' characteristics degrade gradually with the increase of RTA temperature.
CHARACTERISTIC ANALYSIS OF ZNO VARISTORS MADE WITH SPHERICAL PRECIPITATION POWDERS
(1995-07-01)
BAI, SN
;
SHIEH, JS
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TSENG, TY
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Small, uniform and spherical ZnO powders for the fabrication of ZnO varistors were obtained by an aqueous precipitation method. The varistor samples made from the ZnO powders using butylamine and urea as precipitant show excellent surge response characteristics. However, the varistor samples made by the ZnO-butylamine powders gave better electrical properties, including higher nonohmic property and lower leakage current, than those made by the ZnO-urea powders, because the ZnO powders precipitated by butylamine had smaller and more homogeneous size than those precipitated by urea.
EVAPORATION OF A HEATED FALLING LIQUID-FILM INTO A LAMINAR GAS-STREAM
(1995-07-01)
TSAY, YL
;
LIN, TF
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機械工程學系
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Department of Mechanical Engineering
Heat and mass transfer characteristics for a falling liquid film evaporating into a gas stream were investigated. The liquid water film falls along a vertical plate subjected to a uniform heat flux. In the numerical analysis the respective governing equations for the liquid film and gas stream were solved together. An experimental system was also set up to measure the heat transfer coefficient along the wetted wall for various thermal and flow conditions. The measured data are in good agreement with the numerical predictions. It is observed that the latent heat transport connected with the vaporization of the liquid film plays an important role in the transfer processes. A correlation of the Nusselt number for heat transfer from the wetted wall to the liquid film is proposed.
A COMPARISON OF STATISTICAL REGRESSION AND NEURAL-NETWORK METHODS IN MODELING MEASUREMENT ERRORS FOR COMPUTER VISION INSPECTION SYSTEMS
(1995-07-01)
CHANG, CA
;
SU, CT
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工業工程與管理學系
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Department of Industrial Engineering and Management
This paper compares measurement error models for computer vision inspection systems based on the statistical regression method and a neural network-based method. Experimental results demonstrate that both of the models can effectively correct the dimensional measurements of geometric features on a part profile. It also shows that the statistical regression method can perform excellent tasks when the functions for models are carefully selected through statistical testing procedures. On the other hand, varieties of neural network architectures all have good performance when training data are collected carefully. The explicit nonlinear relationship in neural network architectures is very effective in building a general mapping model without specifying the functional forms in advance. While statistical regression methods will continue to play important roles in model building tasks, the neural network-based method will be a very powerful alternative for precision measurement using computer vision systems.
AN ENCRYPTION/SIGNATURE SCHEME WITH LOW MESSAGE EXPANSION
(1995-07-01)
HWANG, SJ
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CHANG, CC
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YANG, WP
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資訊工程學系
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Department of Computer Science
Secrecy, authenticity and integrity are three major services provided by the public key cryptography. To provide these three services via the ElGamal public key cryptosystem and Signature scheme, the message expanding ratio is four and the overhead of communication is heavy. In this paper, a concurrent encryption/signature scheme will be proposed to provide these three services with a lower message expanding ratio. In the new scheme, the signer can encrypt and sign the message concurrently so the signature that serves as the ciphertext is a pair of integers. Thus the message expanding ratio can be decreased to two.
GROWTH OF CEO2 FILMS ON SAPPHIRE AND MGO BY RF MAGNETRON SPUTTERING
(1995-07-01)
TSAIH, WC
;
HUANG, CK
;
TSENG, TY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Epitaxial CeO2 films on (1 $($) over bar$$ 102) sapphire and (100) MgO were grown by rf magnetron sputtering, Substrate temperature, total pressure, and oxygen-to-argon mole ratio were varied to explore the optimal deposition condition. The X-ray diffraction spectra indicate that the degree of crystallinity of the deposited CeO2 films depends on the oxygen-to-argon mole ratio and the substrate temperature, Atomic force microscopy images of the films on sapphire and MgO showed that substrate temperature and total pressure affect surface roughness. The best him surface is smooth with a 0.89 nm root-mean-square roughness, The quality of the films on MgO showed a strong dependence on substrate pretreatments, Epitaxial CeO2 films could be grown on preannealed or pre-etched MgO if substrate temperatures reached higher than 790 degrees C, Additionally, the effect of ion bombardment at low total pressures on the crystallinity of the films was examined by growing the films outside the plasma region, Experimental results indicate that the ion bombardment does not prevent the films from preferred orientation.
COMPOSITIONAL DISORDERING OF ALGAAS/GAAS SUPERLATTICES BY USING THE LOW-TEMPERATURE-GROWN GAAS
(1995-07-01)
TSANG, JS
;
LEE, CP
;
FAN, JC
;
TSAI, KL
;
CHEN, HR
The use of low-temperature (similar to 200 degrees C) grown GaAs by molecular beam epitaxy to induce compositional disordering of AlGaAs/GaAs superlattices has been studied. After furnace annealing between 700 and 850 degrees C for 30 min, an obvious blue shift in the peak wavelength of the superlattice emission is observed by the 77 K photoluminescence (PL), indicating that the emission has been changed from that of the GaAs quantum wells to that of the intermixed AlGaAs. The PL shift and the depth profile of Al concentration measured by secondary ion mass spectrometry indicate that the superlattice is nearly totally disordered after 850 degrees C annealing. (C) 1995 American Vacuum Society.