Browsing by Issue Date, starting with "1994-01-10"

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管管書目　
(1994-01-10)
管管
管管書目　
(1994-01-10)
管管
A CONSISTENT FINITE-ELEMENT FORMULATION FOR NONLINEAR DYNAMIC ANALYSIS OF PLANAR BEAM
(1994-01-15)
HSIAO, KM
;
YANG, RT
;
LEE, AC
;
交大名義發表
;
機械工程學系
A co-rotational finite element formulation for the dynamic analysis of planar Euler beam is presented. Both the internal nodal forces due to deformation and the inertia nodal forces are systematically derived by consistent linearization of the fully geometrically non-linear beam theory using the d'Alembert principle and the virtual work principle. Due to the consideration of the exact kinematics of Euler beam, some velocity coupling terms are obtained in the inertia nodal forces. An incremental-iterative method based on the Newmark direct integration method and the Newton-Raphson method is employed here for the solution of the non-linear dynamic equilibrium equations. Numerical examples are presented to investigate the effect of the velocity coupling terms on the dynamic response of the beam structures.
ON THE POSITIVE SOLUTIONS FOR SEMILINEAR ELLIPTIC-EQUATIONS ON ANNULAR DOMAIN WITH NONHOMOGENEOUS DIRICHLET BOUNDARY-CONDITION
(1994-01-15)
LEE, MG
;
LIN, SS
;
交大名義發表
;
應用數學系
;
National Chiao Tung University
PHASE-TRANSFORMATION OF MO AND W OVER CO OR ITS ALLOY IN CONTACT WITH SI
(1994-01-15)
YANG, FM
;
CHEN, MC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Tungsten or molybdenum deposited on a cold silicon substrate (W/Si or Mo/Si) using an electron-beam gun at a base pressure of 10(-6) Torr, are unable to form a silicide, even when annealed at 900-degrees-C in either ambient N2 or H-2. We present an easy method by which Mo and W silicides can be formed under the same deposition and annealing conditions with the help of an intervened layer of cobalt or its alloy. Investigations were performed on various metallizations of Mo/Co/Si, W/Co/Si, W/Co-Mo/Si, Co-Mo/Si and Co/Mo/Si, annealed in a normal flowing-nitrogen furnace or in ambient H-2. In the Mo/Co/Si systems (or W/Co/Si), Mo (or W) silicide can be formed at 900-degrees-C over CoSi2 which is formed at a lower temperature and is in contact with Si. The residual silicon oxide on the silicon surface is thought to inhibit the silicide formation of W and Mo. The presence of cobalt, which is not impeded by the surface residual silicon oxide or other impurities for silicide formation, can induce silicidation of W and Mo. The reason for silicide formation at higher temperatures in preference to the metal oxide is based on the Ellingham diagram. In the W/Co-Mo/Si system, three silicides Of WSi2, MoSi2 and CoSi2 are formed at a high temperature of 900-degrees-C. A mechanism for phase array of the silicides is proposed. In the Co/Mo/Si system, where stable Co3Mo and Co7Mo6 compounds are formed in advance, no silicide can be formed even at 950-degrees-C.
三味書屋的三味
(1994-01-19)
管管
IN-SITU COMPATIBILIZED POLYMER BLENDS OF PHENOXY AND ABS
(1994-01-31)
CHEN, SH
;
CHANG, FC
;
應用化學系
;
Department of Applied Chemistry
The combination of styrene-acrylonitrile-glycidyl methacrylate (SAG) reactive copolymer and sodium lauryl sulfonate catalyst is able to function as an effective in situ compatibilizer for the otherwise immiscible and incompatible polymer blends of phenoxy and acrylonitrile-butadiene-styrene (ABS). The copolymer formed from the reaction between phenoxy and SAG under melt blending conditions tends to reduce interfacial tension in the melt and results in finer morphological domains of the blends. The presence of this in situ formed compatibilizer also raises the interphase adhesion of the blends and results in significant improvements in mechanical properties. (C) 1994 John Wiley & Sons, Inc.
INTRAMOLECULAR DIELS-ALDER REACTION OF FURANS WITH ALLENYL ETHERS FOLLOWED BY METHYLTHIO GROUP 1,4-REARRANGEMENT
(1994-01-31)
WU, HJ
;
SHAO, WD
;
YING, FH
;
交大名義發表
;
應用化學系
The base-catalyzed intramolecular Diels-Alder reactions of the furfuryl propargyl ethers la-le gave compounds 6a-6e as the major product respectively, a novel reaction involving an intramolecular Diels-Alder reaction followed by a methylthio group 1,4-rearrangement.
PERFORMANCE ANALYSIS OF AN OCR SYSTEM VIA AN ARTIFICIAL HANDWRITTEN CHINESE CHARACTER GENERATOR
(1994-02-01)
TUNG, CH
;
CHEN, YJ
;
LEE, HJ
;
資訊工程學系
;
Department of Computer Science
A handwritten Chinese character generator that generates handwritten Chinese characters with different variations is proposed and used to evaluate the performance of an OCR system. The character generator first generates radicals of a character stroke by stroke and then combines the generated radicals to form a line-vector character. Next, the line-vector character is thickened to obtain a character image. Characters generated by this method will have great variance in shape but will still satisfy the structural constraints. The generated characters are then used to perform two types of evaluations. First, the stability of stroke extractors in terms of stroke number is evaluated. Two stroke extractors, one based on thinning and the other on vectorization, are analyzed. The vectorization-based stroke extractor we propose operates directly on the run length codes of line segments. From experimental results, we find that the thinning-based method is more time-consuming but more stable than the vectorization-based method. Second, the peak performance of a matching module is evaluated and the recognition error caused by stroke extractors is identified.
CONCEPTUAL SURVEY OF PHASE MODULATION BASED WAVELENGTH REGISTERED NETWORKS
(1994-02-01)
KAO, MS
;
LIN, TC
;
電信工程研究所
;
電信研究中心
;
Institute of Communications Engineering
The implementation of a dense wavelength-division multiplexing (WDM) based wide-area network inevitably involves a large number of semiconductor lasers requiring particular temperature and driving current control. The concept of a novel multiwavelength network that uses only one laser source to generate all the carriers needed for the entire network is investigated. The central idea is to use a stable reference laser to generate two sets of optical carriers as the 'carrier supplies' for all network nodes: one set for signal transmission and the other for signal reception. A promising feature of the proposed network is the wavelength registration, that is, all carrier wavelengths are unambiguously identified. This special feature is of importance for a standard wide-area multiwavelength network. Optical phase modulation is extensively employed in the carrier generation as well as in information delivery. A 40-wavelength network is considered with each wavelength carrying 20 phase-modulated microwave subcarriers, a total throughput of 160 Gbit/s per single-mode fibre is estimated.
A NEW OBJECT-ORIENTED METHOD INTEGRATING JACKSON STRUCTURED PROGRAMMING METHOD
(1994-02-01)
CHEN, JY
;
CHEN, YTT
;
資訊工程學系
;
Department of Computer Science
This article presents a new object-oriented method which integrates the Jackson Structured Programming method with an object-oriented approach. The new method analyzes the user's services, identifies attributes from data structure diagrams, and identifies operations from program structure diagrams. Also, this method defers the identification of class relationships until the attributes and operations have been identified, so as to prevent premature decisions. In addition, the concept of ''leading object'' is used to decrease the number of actors and agents and to increase the number of servers in a system. This may enhance reusability of the objects.
MAGNETIC-BEHAVIOR IN PR-CONTAINING TL-BASED AND PB-BASED CUPRATES
(1994-02-01)
KU, HC
;
LAI, CC
;
SHIEH, JH
;
LIOU, JW
;
WU, CY
Magnetic ordering among Pr ions occurs at a relatively high temperature of 17 K in PrBa2Cu3O7, but is absent in Pr2CuO4 and Bi2Sr2PrCu2O8 above 1.6 K. This work extends the study of magnetic properties to other Pr-containing cuprates including TlBa2PrCu2O7, (Pb.6Cu.4)Sr2PrCu2O7 and Pb2Sr2PrCu3O8. Low temperature calorimetric and SQUID measurements show broad peaks in C and dchi/dT in all cases. The onset temperatures are near 10 K, while the maxima in C as well as minima in dchi/dT prevail at about 8 to 5 K. The heat capacity data provides additional information concerning the entropy associated with the magnetic anomalies and large contributions seemingly linear with temperature.
REINFORCEMENT STRUCTURE PARAMETER LEARNING FOR NEURAL-NETWORK-BASED FUZZY-LOGIC CONTROL-SYSTEMS
(1994-02-01)
LIN, CT
;
LEE, CSG
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper proposes a reinforcement neural-network-based fuzzy logic control system (RNN-FLCS) for solving various reinforcement learning problems. The proposed RNN-FLCS is constructed by integrating two neural-network-based fuzzy logic controllers (NN-FLC's), each of which is a connectionist model with a feedforward multilayered, network developed for the realization of a fuzzy logic controller. One NN-FLC performs as a fuzzy predictor, and the other as a fuzzy controller. Using the temporal difference prediction method, the fuzzy predictor can predict the external reinforcement signal and provide a more informative internal reinforcement signal to the fuzzy controller. The fuzzy controller performs a stochastic exploratory algorithm to adapt itself according to the internal reinforcement signal. During the learning process, both structure learning and parameter learning are performed simultaneously in the two NN-FLC's using the fuzzy similarity measure. The proposed RNN-FLCS can construct a fuzzy logic control and decision-making system automatically and dynamically through a reward/penalty signal (i.e., a ''good'' or ''bad'' signal) or through very simple fuzzy information feedback such as ''high,'' ''too high,'' ''low,'' and ''too low.'' The proposed RNN-FLCS is best applied to the learning environment, where obtaining exact training data is expensive. The proposed RNN-FLCS also preserves the advantages of the original NN-FLC, such as the ability to find proper network structure and parameters simultaneously and dynamically and to avoid the rule-matching time of the inference engine in the traditional fuzzy logic systems. Computer simulations were conducted to illustrate the performance and applicability of the proposed RNN-FLCS.
ANALYSIS OF BILATERAL LATCH-UP TRIGGERING IN VLSI CIRCUITS
(1994-02-01)
HUANG, HS
;
CHANG, CY
;
HSU, CC
;
CHEN, KL
;
LIN, JK
4-POSITION SYNTHESIS FOR SPATIAL MECHANISMS WITH 2 INDEPENDENT LOOPS
(1994-02-01)
CHIANG, CH
;
YANG, YN
;
CHIENG, WH
;
HOELTZEL, DA
;
機械工程學系
During the practical implementation of four-position guidance synthesis for the spatial mechanisms, many mathematical models for rigid body guidance design are found to be too complicated to solve especially for up to four positions. Our objectives are to uncover simple and analytical ways to synthesize the single degree-of-freedom, two independent loop spatial mechanisms which are capable of four precision positions. Furthermore, prescribed timing is simultaneously considered for some spatial mechanisms.
TRANSIENT ANALYSIS OF SUBMICRON CMOS LATCHUP WITH A PHYSICAL CRITERION
(1994-02-01)
KER, MD
;
WU, CY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A new physical criterion and an analytical timing model for transient latchup in a p-n-p-n structure are developed and verified. In the new physical transient latchup criterion, two new parameters called the large-signal transient current gains of the parasitic vertical and lateral BJTs in the p-n-p-n structure are defined. If their product rather than the forward beta-gain product becomes larger than unity right after triggering and remains larger than unity, the latchup occurs. With the piecewise-linearized device currents of the parasitic BJTs and the averaged junction depletion and diffusion capacitances in the p-n-p-n structure, the large-signal transient current gains are derived as functions of time and device parameters. Moreover, the dynamic behaviors and the associated timing of transient latchup can also be fully characterized. Model calculation results using the developed criterion and timing model agree very well with both SPICE simulation and experimental results. Thus the developed criterion and timing model can be applied to transient latchup analysis and prediction in CMOS ICs.
VIRTUAL KNOT TECHNIQUE FOR CURVE-FITTING OF RAPIDLY VARYING DATA
(1994-02-01)
HSIEH, HC
;
CHANG, WT
;
電信工程研究所
;
Institute of Communications Engineering
Curve fitting with piecewise splines for rapidly varying data has been a difficult problem. Often, the curve exhibits unwanted ''wiggles'' around those data points whose locations change rapidly in comparison to their neighboring data points. Many methods were proposed to solve this problem using non-homogeneous tension spline or fairing process. In this paper, a new approach using the concept of virtual knots is presented. Since the occurrence of the problem is due to the inconsistency between the parametric spans of the knots and the geometric spans of the data points, a number of virtual knots are inserted into the original knot sequence such that the parametric spans are made more consistent with the geometric spans of the data. With this parametric adjustment, a regularization process is used to find the desired curve. Experimental results show that this technique is efficient to adjust the fairness of the desired curve. This technique can be applied to different spline spaces. In this paper, the usages of this technique in linear B-spline and cubic B-spline spaces are demonstrated.
SOME GOOD MULTIPLIERS FOR RANDOM NUMBER GENERATOR FOR 16-BIT MICROCOMPUTERS
(1994-02-01)
CHANG, PL
;
HWANG, SN
;
KAO, C
;
管理科學系
;
Department of Management Science
In searching for statistically sound multipliers for the prime modulus multiplicative congruential random number generator for 16-bit microcomputers, an exhaustive analysis is conducted over the 10,912 primitive roots of the modulus 2(15)-19=32,749. The result shows that there are only 227 good multipliers among the 10,912 candidate multipliers. Here a multiplier is said to be good if its corresponding generator has good statistical properties and computational efficiency.
GROWTH OF PULSED-LASER DEPOSITED YBCO THIN-FILMS ON YSZ AND YSZ/SI SUBSTRATES
(1994-02-01)
JUANG, JY
;
KAO, RT
;
HSIEH, MC
;
LI, MH
;
CHU, ML
The growth mechanism of superconducting YBCO thin films deposited in - situ on both single crystalline YSZ and YSZ-buffered Si substrates as revealed by scanning tunneling microscopy (STM) are found to be very different. The results are attributed to the initial surface condition of the substrates.
GENERALIZED ON-SHELL WARD IDENTITIES IN STRING THEORY
(1994-02-01)
LEE, JC
;
交大名義發表
;
物理研究所
;
National Chiao Tung University
;
Institute of Physics
It is demonstrated that an infinite set of string-tree level on-shell Ward identities, which are valid to all sigma-model loop orders, can be systematically constructed without referring to the string field theory. As examples, bosonic massive scattering amplitudes are calculated explicitly up to the second massive excited states. Ward identities satisfied by these amplitudes are derived by using zero-norm states in the spectrum. In particular, the inter-particle Ward identity generated by the D2XD2, zero-norm state at the second massive level is demonstrated. The four physical propagating states of this mass level are then shown to form a large gauge multiplet. This result justifies our previous consideration on higher inter-spin symmetry from the generalized worldsheet sigma-model point of view.