Browsing by Issue Date, starting with "1995-05-04"

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DISCRETE GAUGE STATES AND W(INFINITY) CHARGES IN C=1 2D GRAVITY
(1995-05-04)
CHUNG, TD
;
LEE, JC
;
電子物理學系
;
物理研究所
;
Department of Electrophysics
We give a general formula for gauge states at the discrete momenta in Liouville theory. These discrete gauge states carry the w(infinity) charges. As in the case of the 26D (or 10D) string theory, they are decoupled from the correlation functions and can be considered as the symmetry parameters in the old covariant quantization of the theory.
CONTROL OF REGIOSELECTIVITY IN THE DIELS-ALDER REACTIONS OF ALKYL-SUBSTITUTED 1,4-BENZOQUINONES BY BETA-CYCLODEXTRIN AND ITS DERIVATIVES
(1995-05-07)
CHUNG, WS
;
WANG, JY
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
The Diets-Alder reactions of benzoquinones 1-3 with penta-1,3-diene 4 and isoprene 5 are studied in aqueous cyclodextrin solutions, where highly enhanced ortho (6, 8 and 10) and meta (13, 15) regioselectivities are achieved.
CHARACTERISTICS OF GRADED-LIKE MULTIPLE-DELTA-DOPED GAAS FIELD-EFFECT TRANSISTORS
(1995-05-08)
KAO, MJ
;
HSU, WC
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HSU, RT
;
WU, YH
;
LIN, TY
MOLECULAR-BEAM EPITAXY REGROWTH USING A THIN IN LAYER FOR SURFACE PASSIVATION
(1995-05-08)
PENG, CK
;
TU, SL
;
CHEN, SS
;
LIN, CC
;
材料科學與工程學系
管管好個自在老頑童
(1995-05-09)
李美鵑
A FUZZY NEURAL-NETWORK FOR RULE ACQUIRING ON FUZZY CONTROL-SYSTEMS
(1995-05-12)
SHANN, JJ
;
FU, HC
;
交大名義發表
;
資訊工程學系
;
National Chiao Tung University
This paper presents a layer-structured fuzzy neural network (FNN) for learning rules of fuzzy-logic control systems. Initially, FNN is constructed to contain all the possible fuzzy rules. We propose a two-phase learning procedure for this network. The first phase is a error-backprop (EBP) training, and the second phase is a rule pruning. Since some functions of the nodes in the FNN have the competitive characteristics, the EBP training will converge quickly. After the training, a pruning process is performed to delete redundant rules for obtaining a concise fuzzy rule base. Simulation results show that for the truck backer-upper control problem, the training phase learns the knowledge of fuzzy rules in several dozen epochs with an error rate of less than 1%. Moreover, the fuzzy rule base generated by the pruning process contains only 14% of the initial fuzzy rules and is identical to the target fuzzy rule base.
GROWTH OF EPITAXIAL-LIKE (SR0.5BA0.5)NB2O6 FERROELECTRIC-FILMS
(1995-05-15)
LIN, WJ
;
TSENG, TY
;
LIN, SP
;
TU, SL
;
YANG, SJ
Epitaxial-like (Sr0.5Ba0.5)Nb2O6 (SBN) films were successfully grown on (100) silicon substrates, using [002] CeO2 as the buffer layer and [001]YBa2Cu3O7-x (YBCO) as the base electrode. The theta-2 theta scan and phi-scan X-ray diffraction suggest that [210](SBN)//[100](YBCO)//[110]CeO2//[110](si). The ferroelectric hysteresis curves measured by the modified Sawyer-Tower technique show that the epitaxial-like SBN/YBCO/CeO2/Si films possess substantially better ferroelectricity than the polycrystalline SBN/Pt(Ti)/Si films. The remanent polarization (P-r) and coercive field (E(c)) are, respectively, P-r = 27.2 mu C/cm(2) and E(c) = 24.8 kV/cm.
IMPROVING THE UNDOING OF SOLITON INTERACTION WITH OPTICAL-PHASE CONJUGATION BY PHASE ALTERNATION BETWEEN NEIGHBORING SOLITONS
(1995-05-15)
CHI, S
;
DUNG, JC
;
WEN, SF
;
光電工程學系
;
電信研究中心
The undoing of the soliton interaction with the optical phase conjugation by the phase alternation between neighboring solitons is numerically studied. When the phase alternation is larger than 90-degrees, the undoing of the soliton interaction is good even when the conjugation is applied at the distance where the solitons interact seriously.
FINITE-CONICAL-WELL MODEL FOR VERTICALLY ADSORBED DIATOMIC-MOLECULES
(1995-05-15)
SHIH, YT
;
CHUU, DS
;
MEI, WN
;
電子物理學系
;
光電工程研究所
POLARIZATION-INDEPENDENT OPTICAL SWITCH COMPOSED OF HOLOGRAPHIC OPTICAL-ELEMENTS
(1995-05-15)
HUANG, YT
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A novel 2 x 2 polarization-independent optical switch with holographic optical elements is proposed. The switch consists of an electro-optic half-wave plate sandwiched between two pairs of holographic polarization beam splitters. Normally incident input and output couplings of this compact and Lightweight device provide better flexibility and easier alignment for system applications.
SYNTHETIC STUDIES TOWARDS FAVELINE METHYL-ETHER
(1995-05-15)
HO, TL
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CHEN, CK
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應用化學系
;
Department of Applied Chemistry
A convergent approach to faveline methyl ether based on Claisen rearrangement is delineated Thus the benzylic and allylic alcohol substrate was assembled by a Grignard reaction, and the rearrangement product was oxidized and cyclized. Double bond isomers of faveline methyl ether were obtained.
HIGH-BARRIER PT/AL/N-INP DIODE
(1995-05-25)
HUANG, WC
;
LEI, TF
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LEE, CL
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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 Pt/Al/n-InP, contact diode, which has a good I-V characteristic is studied. It has a barrier height of 0.74eV, which increases to 0.99eV when it is treated with HF, an ideality factor of 1.18, and a reverse leakage current of 5.5 x 10(-8)A/cm(2) at -3V. This good performance is believed to be due to the combined effects of the formation of an interfacial oxide layer and fluorine passivation on the surface.
IMPROVED SYLLABLE-BASED CONTINUOUS MANDARINE SPEECH RECOGNITION USING INTERSYLLABLE BOUNDARY MODELS
(1995-05-25)
CHANG, S
;
CHEN, SH
;
電信工程研究所
;
電信研究中心
;
Institute of Communications Engineering
A novel approach to compensate for the intersyllable coarticulation effect on continuous Mandarin speech recognition by supplementing the syllable HMM models with intersyllable boundary models is proposed. Experimental results show that the syllable recognition errors of a speaker-dependent recognition task are reduced by 24%.
A COMPARISON OF SIMILARITY MEASURES OF FUZZY VALUES
(1995-05-26)
CHEN, SM
;
YEH, MS
;
HSIAO, PY
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交大名義發表
;
資訊工程學系
This paper extends the work of Pappis and Karacapilidis (1993) to present and compare the properties of several measures of similarity of fuzzy values. The measures examined in this paper are based on the geometric model, the set-theoretic approach, and the matching function S we presented in (Chen, 1988). It is shown that several properties are common to all measures and some properties do not hold for all of them.
THICKNESS EFFECT ON HYDROGEN PLASMA TREATMENT ON POLYCRYSTALLINE SILICON THIN-FILMS
(1995-05-29)
LIOU, BW
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WU, YH
;
LEE, CL
;
LEI, TF
;
電子工程學系及電子研究所
FRACTURE-TOUGHNESS OF PC/PBT BLEND-BASED ON J-INTEGRAL METHODS
(1995-05-31)
LU, ML
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CHANG, FC
;
應用化學系
;
Department of Applied Chemistry
The fracture toughness of a polycarbonate/poly(butylene terephthalate) (PC/PBT) blend was determined using three different J-integral methods, ASTM E813-81, E813-87, and hysteresis energy. The critical J values (J(1c)) obtained are largely independent of the cross-head speed (range from 0.5 to 50 mm/min). ASTM E813-81 and hysteresis energy methods result in comparable J(1c) values, while the E813-87 method estimates J(1c) to be 60-80% higher. The critical displacement determined from the plots of hysteresis (energy and ratio) and the true crack growth length vs. displacement is very close. This indicates that the critical displacement determined by the hysteresis energy method is indeed the displacement at the onset of crack initiation and the corresponding J(1c) represents a physical event of crack initiation. (C) 1995 John Wiley and Sons, Inc.
BLENDS OF POLY(ETHYLENE-TEREPHTHALATE) WITH CO[POLY(ETHYLENE TEREPHTHALATE-P-OXYBENZOATE)] .2. COMPOSITION EFFECT ON THE RATE OF CRYSTALLIZATION
(1995-05-31)
OU, CF
;
LIN, CC
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Poly(ethylene terephthalate) (PET) was blended with four different kinds of eo[poly(ethylene terephthalate-p-oxybenzoate)] copolyesters, designated P28, P46, P64, and P82, with the level of copolyester varing from 1 to 15 wt%. All samples were prepared by melt-mixing in a Brabender Plasticorder for 8 min. The crystallization behavior of samples were then studied via DSC. The results indicate that these four copolyesters accelerate the crystallization rate of PET in a manner similar to that of a nucleating agent. The acceleration of the PET crystallization rate was most pronounced in the PET/P28 blends with a maximum level at 10 wt% of P28, and in the PET/P82 blends, at 5 wt% of P82. The melting endotherm onset temperatures and the melting peak widths for the blends are comparable with those of neat PET. These results imply that the stability of PET crystalline phase in the blends does not change by blending. The observed changes in crystallization behavior, however, are explained by the effect of the physical state of the copolyester during PET crystallization as well as the content of the p-oxybenzoate (POB) moiety incorporated into the blends. (C) 1995 John Wiley and Sons, Inc.
IN-SITU REACTIVE COMPATIBILIZED NORYL/LCP BLENDS
(1995-05-31)
CHANG, DY
;
CHANG, FC
;
應用化學系
;
Department of Applied Chemistry
This article reveals that the already known improved properties of the thermoplastic-liquid crystalline polymer (LCP) blends can be further improved substantially over the corresponding noncompatibilized counterparts by using a reactive in situ type compatibilizer, the styrene-glycidyl methacrylate (SG) copolymer. This SG copolymer has been demonstrated in this article to be an effective reactive compatibilizer to improve the processability, heat deflection temperature, and mechanical properties of Noryl/LCP blends. The epoxy functional groups of the SG copolymer can react with the end groups of PPO (in Noryl) and LCP. The in situ-formed SG-g-LCP copolymer tends to reside along the interface of Noryl-LCP and reduces the interfacial tension during melt processing. The resultant LCP fibers in the Noryl matrix of the compatibilized blends have a higher aspect ratio because the fibers become finer, longer, and tend to form lamellate domains with a greater interphase contact area than those from the noncompatibilized blends. The compatibilized blends also improve the interphase adhesion between Noryl and LCP. The presence of ethyl triphenylphosphonium bromide catalyst promotes the grafting reaction to improve blend compatibilization. (C) 1995 John Wiley and Sons, Inc.
RUBBING-INDUCED MOLECULAR ALIGNMENT ON AN ORIENTING LAYER OF POLYIMIDE WITH AND WITHOUT ALKYL SIDE-CHAINS
(1995-06-01)
HUANG, JY
;
LI, JS
;
JUANG, YS
;
CHEN, SH
;
交大名義發表
The rubbing-induced molecular alignment on a surface of polyimide with and without branched alkyl side chains was investigated with optical phase retardation measurement, atomic force microscopy (AFM), and second-harmonic generation (SHG). Our AFM results suggest that the rubbing-induced microgrooves play a minor role in aligning liquid crystal (LC) molecules. From the SHG studies, the detailed in-plane distribution of a LC monolayer on rubbed polymers was deduced, and the polar angle of the LC molecules was found to vary with the rubbing strength exerted on an alkyl-branched polymer. The polar angle of the LC monolayer on an alkyl-branchless main-chain polyimide film was observed to be independent of the rubbing strength. We propose a simple molecular model to reconcile these experimental results.
ANALYSIS OF TRANSPORT CRITICAL-CURRENT DENSITY IN A BENT BI-PB-SR-CA-CU-O SILVER-SHEATHED TAPE
(1995-06-01)
LEE, WD
;
HORNG, L
;
YANG, TJ
;
CHIOU, BS
;
電子物理學系
The experimental results on the magnetic behavior of the transport critical current density in a bent Bi based superconducting tape have shown that the irreversible strain limit epsilon(irrev) for the onset of permanent strain damage to Ag sheathed superconductors is not dependent on the magnetic field, nor does the normalized I-c(H, epsilon)/I-c(0, epsilon) current depend on the strain at least up to 0.5 T at 77 K. Such a behavior has been attributed to two reasons: (1) The intrinsic pinning properties are unchanged in a bent tape; (2) The strain effect is extrinsic and arises from superconductor cracks. Thus, based on these arguments a Josephson junction tunneling model with cracks in between the grain boundaries is proposed to explain the J(c) behavior quite well for a bent granular high-T-c superconducting tape. Our model calculation shows that the critical current density of high-T-c superconductor may be enhanced by increasing the strain tolerance epsilon(irrev) and the epsilon(irrev) is determined by the properties of Ag sheathed tape and its related material parameters, which are dependent on the connectivity of the grain boundaries.