Browsing by Issue Date, starting with "1995-04-14"

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FUZZY ADAPTIVE LEARNING CONTROL NETWORK WITH ONLINE NEURAL LEARNING
(1995-04-14)
LIN, CT
;
LIN, CJ
;
LEE, CSG
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper addresses the structure and the associated on-line learning algorithms of a feedforward multilayered connectionist network for realizing the basic elements and functions of a traditional fuzzy logic controller. The proposed Fuzzy Adaptive Learning COntrol Network (FALCON) can be contrasted with the traditional fuzzy logic control systems in their network structure and learning ability. The connectionist structure of the proposed FALCON can be constructed from training examples by neural learning techniques to find proper fuzzy partitions, membership functions, and fuzzy logic rules. Two complementary on-line structure/parameter learning algorithms, FALCON-FSM and FALCON-ART, are proposed for constructing the FALCON dynamically. The FALCON-FSM combines the backpropagation learning scheme for parameter learning and a fuzzy similarity measure for structure learning. The FALCON-FSM can find proper fuzzy logic rules, membership functions, and the size of output partitions simultaneously. In the FALCON-FSM algorithm, the input and output spaces are partitioned into ''grids''. The grid-typed space partitioning certainly makes both the fuzzy logic controller software emulation and fuzzy chip implementation convenient. However, as the number of input/output variables increases, the number of partitioned grids will grow combinatorially. To avoid the problem of combinatorial growth of partitioned grids in some complex systems, the FALCON-ART algorithm is developed, which can partition the input and output spaces in a more flexible way based on the distribution of the training data. The FALCON-ART combines the backpropagation learning scheme for parameter learning and a fuzzy ART algorithm for structure learning. The FALCON-ART can on-line partition the input and output spaces, tune membership functions and find proper fuzzy logic rules dynamically. Computer simulations were conducted to illustrate the performance and applicability of both FALCON-FSM and FALCON-ART learning algorithms.
HYSTERETIC BEHAVIOR OF THE TRANSPORT CRITICAL-CURRENT DENSITY IN A BENT BI-PB-SR-CA-CU-O SILVER-SHEATHED TAPE
(1995-04-15)
LEE, WD
;
HORNG, L
;
YANG, TJ
;
CHIOU, BS
;
電子物理學系
ELECTRICAL-PROPERTIES OF BORON-DOPED DIAMOND FILMS AFTER ANNEALING TREATMENT
(1995-04-15)
CHEN, CF
;
CHEN, SH
;
交大名義發表
;
材料科學與工程學系
;
National Chiao Tung University
Trimethylborate (B(OCH3)(3)) was used to obtain boron-doped (p-type) polycrystalline diamond thin films on a silicon substrate using microwave plasma-assisted chemical vapor deposition. The effect of the doping agent (trimethylborate) was characterized in terms of electrical properties, and the current-voltage (I-V) characteristics of the boron-doped diamond films using aluminum as contacts at room temperature were examined. A surprising result was that annealing improved the electrical properties of boron-doped diamond films. As the boron concentration increased, the forward current decreased because of the effects of impurity scattering, and the I-V characteristics were still rectified. After the samples were annealed in a helium ambient at 900 degrees C for 30 min, the I-V characteristics changed: the higher the concentration of boron in the doped diamond films, the more ohmic was the observed behavior. The differences in the I-V characteristics of annealed and non-annealed films were subsequently confirmed by Fourier transform infrared spectroscopy (FTIR), capacitance-voltage (C-V) measurements, and cathodoluminescence (CL) experiments. The results of these experiments demonstrated that the annealing treatment caused boron atoms initially in inactive sites (e.g. interstitial or clustering sites) to be incorporated into substitutional sites. The increase in substitutional boron atoms altered the I-V characteristics of the boron-doped diamond films.
LUMINESCENCE OF LOW-TEMPERATURE GAAS IN A GAAS/IN0.2GA0.8AS MULTIPLE-QUANTUM-WELL STRUCTURE
(1995-04-17)
CHENG, TM
;
CHANG, CY
;
HUANG, JH
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
RESONANT FREQUENCIES OF A MICROWAVE PACKAGE WITH VERTICAL DIAPHRAGMS ATTACHED TO THE TOP COVER
(1995-04-20)
CHUNG, SJ
;
CHEN, HH
;
交大名義發表
;
電信工程研究所
;
National Chiao Tung University
The resonant frequencies of the modes in a cabineted microwave package are investigated by the mode-matching method. The upper region of the package is partitioned into several cabinets using vertical diaphragms of a same depth and of negligible thickness. Numerical results are shown to agree with those of the measurement. The change of the resonant frequencies with the diaphragm depth is presented and explained. It is found that the resonance-free frequency bands can be broadened by suitably designing the positions and the depth of the diaphragms. (C) 1995 John Wiley & Sons, Inc.
A GENERALIZATION OF THE STABLE MATCHING PROBLEM
(1995-04-21)
TAN, JJM
;
HSUEH, YC
;
交大名義發表
;
資訊工程學系
;
National Chiao Tung University
It is known that there may not exist any stable matching for a given instance of the stable roommates problem. A stable partition is a structure that generalizes the notion of a stable matching; Tan (1991) proved that every instance of the stable roommates problem contains at least one such structure. In this paper we propose a new algorithm for finding a stable partition, and hence a new algorithm for finding a stable matching if one exists. Our algorithm processes the problem dynamically as long as certain relative preference orders are maintained. Some theoretical results about stable partitions are also presented.
青蛙案件物語
(1995-04-22)
管管
COMPACT EMBEDDING OF BINARY-TREES INTO HYPERCUBES
(1995-04-28)
CHEN, CC
;
CHEN, RJ
;
資訊工程學系
;
Department of Computer Science
COGNITIVE-MAP-BASED DECISION-ANALYSIS BASED ON NPN LOGICS
(1995-04-28)
CHEN, SM
;
交大名義發表
;
資訊工程學系
;
National Chiao Tung University
;
Department of Computer Science
This paper presents a new method for cognitive-map-based decision analysis based on negative-positive-neutral (NPN) logics, where an efficient algorithm is proposed for performing interval-based inexact reasoning automatically. The algorithm performs inexact reasoning via constructing a sprouting tree. The time complexity of the proposed algorithm is O(nm), where n is the number of cognitive units in the cognitive map, m is the length of a closure path, and max(m) = 2n.
AN OBJECT-ORIENTED APPROACH TO CONSTRUCTING COMMUNICATION PROTOCOLS
(1995-05-01)
CHEN, JL
;
WANG, FJ
;
TING, YC
;
交大名義發表
;
資訊科學與工程研究所
The development of communication protocols for computer networks and distributed systems is an increasingly complex and cost-sensitive process. This paper presents an object-oriented concurrent (OOC) model for the development of communication protocols. This model consists of three kinds of entities: data entities, which represent the communicated data units, state entities, which describe their behavior, and connection, entities, which are responsible for communication services. The state transitions in a protocol are modeled by using state entities, and a communication service is performed by a group of connection and state entities. A C++ library based on our OOC model is described that contains three class hierarchies, for data, state; and connection entities, respectively In addition, an approach to constructing a protocol using this OOC model and the library is presented. An example in which a T.62 protocol is constructed shows that this approach provides a high level of modeling, concurrency, and reusability.
A CMOS TRANSISTOR-ONLY 8-B 4.5-MS/S PIPELINED ANALOG-TO-DIGITAL CONVERTER USING FULLY-DIFFERENTIAL CURRENT-MODE CIRCUIT TECHNIQUES
(1995-05-01)
WU, CY
;
CHEN, CC
;
CHO, JJ
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Fully-differential current-mode circuit techniques are developed for the design of a pipelined current-mode analog-to-digital converter (IADC) in the standard CMOS digital processes. In the proposed IADC, the 1-b-per-stage architecture based on the reference nonrestoring algorithm is adopted. Thus large component ratios can be avoided and the linearity errors caused by device mismatches can be minimized. As one of the key subcircuits in the IADC, an offset-canceled high speed differential current comparator (CCMP) is proposed and analyzed. In the CCMP, the subtractions of offsets are performed in the current domain without floating capacitors. Moreover, the other key subcircuit, the current sample-and-hold amplifier (CSHA), is also developed to realize the pipeline architecture. An experimental chip for the proposed IADC has been fabricated in 0.8-mu m n-well CMOS technology. Using a single 5-V power supply, the fabricated IADC can be operated at 4,5-Ms/s conversion rate with a signal-to-noise-and-distortion-ratio (SNDR) of 51 dB (effective 8.2-b) for the input signal at 453 kHz. For 8-b resolution, the fabricated IADC can be operated at 4,5-Ms/s conversion rate with both differential nonlinearity (DNL) and integral nonlinearity (INL) below +/-0.6 LSB. The power consumption and the active chip area are 16 mW/b and 0.73 mm(2)/b, respectively.
AN ULTRA-LOW COST AND MINIATURE 950-2050 MHZ GAAS MMIC DOWNCONVERTER .1. DESIGN APPROACH AND SIMULATION
(1995-05-01)
HSIEH, TH
;
WANG, H
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WANG, TH
;
CHEN, TH
;
CHIANG, YC
A miniature ultra low cost 950-2050 MHz GaAs MMIC downconverter has been designed for satellite TV application using a 1-mu m gate-length, ion-implanted GaAs MESFET foundry process. To accurately predict circuit performances, both linear and nonlinear equivalent circuit models have been developed to characterize the RF and de behaviors of device. Modeled simulation results show correspondence with the experimental data. This monolithic downconverter is comprised of an RF LNA, a dual-gate MESFET mixer, an IF variable gain amplifies and a varactor tuned oscillator. The primary design specifications are (1) 50-dB conversion gain, (2) 4-dB noise figure, (3) more than 40-dB gain controllable range, and (4) 50-dBc third-order intermodulation distortion. The chip size is 1.4 x 1.5 x 0.18 mm(3). It is encapsulated in a standard low cost mm plastic package. Moreover, this downconverter IC is promising for miniaturization and cost-reduction of a DBS receiver The detailed measured characteristics will be presented in part-II of this paper.
COMPLETELY SELF-STARTING PICOSECOND AND FEMTOSECOND KERR-LENS MODE-LOCKED TI-SAPPHIRE LASER
(1995-05-01)
SHIEH, JM
;
GANIKHANOV, F
;
LIN, KH
;
HSIEH, WF
;
PAN, CL
Completely self-starting and stable operation of a Kerr-lens mode-locked Ti:sapphire laser was realized in both picosecond and femtosecond regimes. The cavity has a symmetric X configuration with soft aperturing. Enhanced Kerr nonlinearity and reduced backscattering effects were thought to be key to obtaining stable self-starting self-mode-locked operation from 765 to 815 nm far the picosecond regime and from 770 to 835 nm for the femtosecond regime. The mode-locking starting time as measured by the onset of the second-harmonic signal ranged from 300 ms to 2 s, depending on cavity alignment. Preliminary data also suggest that intracavity intensity fluctuation necessary for the laser to evolve into stable mode locking could be as short as 10-40 ps.
STRONG ENHANCEMENT OF THE OPTICAL AND ELECTRICAL-PROPERTIES, AND SPONTANEOUS FORMATION OF AN ORDERED SUPERLATTICE IN (111)B ALGAAS
(1995-05-01)
CHIN, A
;
LIN, HY
;
HSIEH, KY
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Strong enhancement in the luminescence intensity is observed in Al0.22Ga0.78As epitaxial layers grown on misoriented (111)B GaAs as compared to those simultaneously grown on (100) GaAs. For a 1 degrees misorientation the luminescence intensity is almost 10 to 1000 times that of the (100) layers, depending on the growth temperature. Room temperature electron mobility for 3 degrees misoriented (111)B Al0.18Ga0.82As is 19% higher than that for side-by-side grown (100). The strong luminescence associated with a large red shift of 90 meV and the 19% mobility enhancement are related to the long range composition ordering in (111)B AlGaAs, which is observed by cross-sectional transmission electron microscopy in a 280 Angstrom Al0.4GaAs quantum well heterostructure with Al0.7GaAs barriers grown on (111)B GaAs substrates.
SHIELDING EFFECT OF A DIAPHRAGM IN A PACKAGED MICROSTRIP CIRCUIT
(1995-05-01)
CHEN, HH
;
CHUNG, SJ
;
交大名義發表
;
電信工程研究所
;
National Chiao Tung University
The scattering of a diaphragm in a packaged microstrip line is investigated using the mode-matching method together with the method of lines. Instead of analyzing the discontinuity in the microstrip, this paper tackles the variation of the waveguide housing, The influences of the thickness and the depth of the diaphragm on the scatterings of the dominant mode and higher-order modes are analyzed based on a comparison of the modal power distributions, Finally, the shielding effect of a pair of closely spaced diaphragms is investigated.
DOCUMENT-RETRIEVAL USING KNOWLEDGE-BASED FUZZY INFORMATION-RETRIEVAL TECHNIQUES
(1995-05-01)
CHEN, SM
;
WANG, JY
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資訊工程學系
;
Department of Computer Science
A knowledge-based approach for fuzzy information retrieval is proposed, where interval queries and weighted-interval queries are allowed for document retrieval, In this paper, knowledge is represented by a concept matrix, where the elements in a concept matrix represent relevant values between concepts, The implicit relevant values between concepts are inferred by the transitive closure of the concept matrix based on fuzzy logic. The proposed method is more flexible than the ones presented in [6] and [11] due to the fact that it has the capability to deal with interval queries and weighted-interval queries.
A NOVEL CORDIC-BASED ARRAY ARCHITECTURE FOR THE MULTIDIMENSIONAL DISCRETE HARTLEY TRANSFORM
(1995-05-01)
GUO, JI
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LIU, CM
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JEN, CW
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資訊工程學系
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電控工程研究所
In this paper, a coordinate rotation digital computer (CORDIC)-based array architecture is presented for computing the multidimensional (M-D) discrete Hartley transform (DHT). Since the kernel of the M-D DHT is inseparable, the M-D DHT problems cannot be computed through the 1-D DHT's directly. Bracewell et al. have presented an algorithm for the M-D DHT through the 1-D DHT's. The existing hardware architectures have been designed using this algorithm. However, the postprocessing required in the algorithm leads to high hardware overhead. This paper presents a new algorithm to compute M-D DHT through a special 1-D transform which is derived through considering both the separable computation and the efficient implementation with CORDIC architectures. This algorithm provides a direct way to compute the M-D DHT separably through 1-D transforms with simpler postprocessing than that in Bracewell's approach. Also, the algorithm exploits the symmetry of the triangular functions to reduce the computational complexity. Using this algorithm, we design an array architecture for the M-D DHT. This architecture features a systolic computing style, PE's with a CORDIC structure, low I/O cost, and the encapsulated new M-D DHT algorithm.
BOLOMETRIC RESPONSE OF HIGH-T-C SUPERCONDUCTING DETECTORS TO OPTICAL PULSES AND CONTINUOUS WAVES
(1995-05-01)
CHEN, RC
;
WU, JP
;
CHU, HS
;
交大名義發表
;
機械工程學系
This work presents a thermal analysis on predicting the temperature increase and the voltage response of high-T-c superconducting bolometers. Two heat transfer models, that is, the surface heating model and the heat generation model considering the skin depth, are introduced and compared. The surface heating model is found to be valid only for situations where the skin depth is much smaller than the film thickness. To consider the thermal boundary resistance between film and substrate, a radiation-boundary-condition model based on acoustic mismatch model (AMM) and an interfacial-layer model (ILM) are employed. The thermal boundary resistance significantly influences the voltage response. Additionally, several common substrates are examined. SrTiO3 (100) or LaAlO3 (100) is a better substrate for high-T-c superconducting bolometers. One interesting finding was that when compared with experimental data, all the theoretical values from the present study as well as the other previously theoretical treatment overestimate the voltage response near the transition temperature.
A NOVEL EXTRACTION TECHNIQUE FOR THE EFFECTIVE CHANNEL-LENGTH OF MOSFET DEVICES
(1995-05-01)
LI, HH
;
WU, CY
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A novel method using the charge pumping technique for extracting the effective channel length of MOSFET devices is presented, in which the effective area approach is used and the edges of the area are defined clearly. It is shown that the extracted effective channel length is independent of the measuring biases and the proposed new method is simple, accurate, and reliable, as compared to those using the I-V method. With the knowledge of the device dopant profiles, the extracted channel length with 0.01 mu m accuracy can be achieved. Moreover, the proposed method is applicable to either n- or p-channel, conventional or LDD, surface or buried channel MOSFET's.
AN IMPLEMENTATION OF AN EXTERNAL PAGER INTERFACE ON BSD UNIX
(1995-05-01)
WANG, HH
;
LU, PK
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CHANG, RC
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資訊工程學系
;
Department of Computer Science
We have designed and implemented an external pager facility on the ConvexOS for Convex supercomputers to enhance memory management capability within the kernel. A group of generic interfaces that can be used to construct a memory manager at user level is proposed. Furthermore, a highly modularized subsystem that provides dynamic configuration and portability is presented.