Browsing by Issue Date, starting with "1993-07-22"

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CONTINUOUS-WAVE VISIBLE INGAP/INGAALP QUANTUM-WELL SURFACE-EMITTING LASER-DIODES
(1993-07-22)
TAI, K
;
HUANG, KF
;
WU, CC
;
WYNN, JD
;
電子物理學系
Vertical cavity top surface emitting lasers in the 0.66 mum visible spectral region were fabricated by the metal-organic chemical vapour deposition technique. The continuous wave threshold currents I(th) are 3.9 and 4.6 mA at -75 and -25-degrees-C, respectively, for 15 mum diameter devices. The lasers can also be operated at room temperature, but only in a pulsed mode with an I(th) of 12 mA at 25-degrees-C.
CONTINUOUS-WAVE VISIBLE INGAP/INGAALP QUANTUM-WELL SURFACE-EMITTING LASER-DIODES
(1993-07-22)
TAI, K
;
HUANG, KF
;
WU, CC
;
WYNN, JD
;
電子物理學系
Vertical cavity top surface emitting lasers in the 0.66 mum visible spectral region were fabricated by the metal-organic chemical vapour deposition technique. The continuous wave threshold currents I(th) are 3.9 and 4.6 mA at -75 and -25-degrees-C, respectively, for 15 mum diameter devices. The lasers can also be operated at room temperature, but only in a pulsed mode with an I(th) of 12 mA at 25-degrees-C.
EFFECT OF LATERAL WALLS ON THE PROPAGATION CHARACTERISTICS OF FINITE-WIDTH CONDUCTOR-BACKED COPLANAR WAVE-GUIDES
(1993-07-22)
TIEN, CC
;
TZUANG, CKC
;
MONROE, J
;
傳播研究所
;
Institute of Communication Studies
The connection of the side planes of finite-width conductor-backed coplanar waveguide (FW-CBCPW) to the ground through lateral walls suppresses the undesired microstrip-like (MSL) mode and provides a wide frequency range over which singlemode propagation occurs. The leakage or resonance phenomena of the higher-order modes can be avoided, if the distance separating the lateral walls is carefully designed.
鷦鷯幾隻
(1993-07-23)
管管
RATE COEFFICIENTS OF THE REACTIONS OF CN AND NCO WITH O2 AND NO2 AT 296-K
(1993-08-01)
YOU, YY
;
WANG, NS
;
交大名義發表
;
應用化學系
;
National Chiao Tung University
The rate coefficients of the reactions of CN and NCO radicals with O2 and NO2 at 296 K: (1) CN + O2 --> products; (2) CN + NO2 --> products; (3) NCO + O2 --> products and (4) NCO + NO2 --> products have been measured with the laser photolysis-laser induced fluorescence technique. We obtained k1 = (2.1 +/- 0.3) x 10(-11) and k2 = (7.2 +/- 1.0) x 10(-11) cm3 molecule-1 s-1 which agree well with published results. As no reaction was observed between NCO and O2 at 297 K, an upper limit of k3 < 4 x 10(-17) cm3 molecule-1 s-1 was estimated. The reaction of NCO with NO2 has not been investigated previously. We measured k4 = (2.2 +/- 0.3) x 10(-11) cm3 molecule-1 s-1 at 296 K.
COLOR IN UNITED-STATES AND TAIWANESE INDUSTRIAL ADVERTISING
(1993-08-01)
HUANG, JH
;
交大名義發表
;
管理科學系
;
National Chiao Tung University
;
Department of Management Science
Colors invoke emotional responses and affect subjects' perception of the advertized product. This study compares the usage of colors in business-to-business advertisements in the United States and Taiwan. The results of the study indicate that the usage of color is affected by culture: American ads use more brown and less yellow than Taiwanese ads. The implications for color use in advertising across national boundaries are discussed.
ON ESTIMATION AND PREDICTION PROCEDURES FOR AR(1) MODELS WITH POWER TRANSFORMATION
(1993-08-01)
LEE, JC
;
TSAO, SL
;
統計學研究所
;
Institute of Statistics
The power transformation of Box and Cox (1964) has been shown to be quite useful in short-term forecasting for the linear regression model with AR(1) dependence structure (see, for example, Lee and Lu, 1987, 1989). It is crucial to have good estimates of the power transformation and serial. correlation parameters, because they form the basis for estimating other parameters and predicting future observations. The prediction of future observations is the main focus of this paper. We propose to estimate these two parameters by minimizing the mean squared prediction errors. These estimates and the corresponding predictions compare favourably, via revs and simulated data, with those obtained by the maximum likelihood method. Similar results are also demonstrated in the repeated measurements setting.
AN AREA TIME-EFFICIENT MOTION ESTIMATION MICRO CORE
(1993-08-01)
CHEN, SG
;
電子工程學系及電子研究所
;
電子與資訊研究中心
;
Department of Electronics Engineering and Institute of Electronics
;
Microelectronics and Information Systems Research Center
An efficient micro architecture for motion estimation is proposed. It achieves better time and area performance than the existing structures. Through pipelining and effective manipulation of 2's complement arithmetic, the adder complexity is kept to its lowest, while speed for a combined subtraction, absolution and accumulation operations is made as fast as a carry-save addition (CSA). Together with a new DCT algorithm, the micro structure is further expanded and tailored to facilitate efficient execution of other video operations like DCT and filtering operations.
METHOD FOR MEASURING THE RETARDATION OF A WAVE PLATE
(1993-08-01)
SHYU, LH
;
CHEN, CL
;
SU, DC
;
交大名義發表
;
光電工程學系
An electro-optic modulator applied to a carrier frequency is used to measure the retardation of a wave plate. This method is not only suitable for any wave plate but also can be operated in real time.
TUNNEL OXIDE PREPARED BY THERMAL-OXIDATION OF THIN POLYSILICON FILM ON SILICON (TOPS)
(1993-08-01)
WU, SL
;
LEE, CL
;
LEI, TF
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This letter presents a textured tunnel oxide, TOPS, prepared by thermally oxidizing a thin polysilicon film on a Si substrate. Due to the rapid diffusion of oxygen through the grain boundaries of the thin polysilicon into Si substrate and the enhanced oxidation rate at the grain boundaries, a textured Si/SiO2 interface is obtained. The textured interface results in the localized high fields and enhances electron injection into TOPS. The TOPS exhibits a higher electron injection efficiency, a better immunity to the electron trapping and the interface state generation under the high-field operation, and a higher asymmetric injection polarity as compared to the normal oxide.
AMBIPOLAR PERFORMANCES OF NOVEL AMORPHOUS SILICON-GERMANIUM ALLOY THIN-FILM TRANSISTORS
(1993-08-01)
HSIEH, SW
;
CHANG, CY
;
LEE, YS
;
LIN, CW
;
WU, BS
The limitation of low hole mobility in hydrogenated amorphous silicon thin-film transistors (a-Si:H TFTs) was overcome in this present work by utilizing hydrogenated amorphous silicon-germanium (a-Si1-xGex:H) alloys as the active channel of TFTs. The performance of hydrogenated amorphous silicon-germanium thin film transistors (a-SiGe:H TFTs) was optimized by switching the germane-to-silane flow ratio. The fabricated a-SiGe:H TFT with 12 at% germanium content was measured as possessing an electron mobility of 0.71 cm2/V.s and a hole mobility of 0.54 cm2/V.s. The on/off current ratio ranging over almost six orders of magnitude in both conduction modes was obtained. Thus a-SiGe:H TFT has offered the opportunity for upgrading of a-Si:H TFTs and would be feasible for application in [CMOS] circuits.
ANALYSIS OF THE EFFECTS OF A RESISTIVELY COATED UPPER DIELECTRIC LAYER ON THE PROPAGATION CHARACTERISTICS OF HYBRID MODES IN A WAVE-GUIDE-SHIELDED MICROSTRIP USING THE METHOD OF LINES
(1993-08-01)
CHUNG, SJ
;
WU, LK
;
交大名義發表
;
傳播研究所
;
National Chiao Tung University
In this paper, propagation characteristics of even-symmetric hybrid modes in a waveguide-shielded microstrip in the presence of a resistively coated dielectric layer affixed to the top cover of the housing is analyzed with the method of lines. The resistive boundary condition is employed to model the resistive film. A shielded microstrip line having a unity strip-width-to-substrate-thickness ratio (i.e., w/h1 = 1) placed on top of a 0.635-mm-thick alumina substrate is considered. Based on a 10h1 x 7h1 reference housing, four different housing arrangements are obtained by varying the structural parameters of the resistively coated dielectric layer. Results obtained indicate that the effects of both the housing walls and the resistively coated upper dielectric layer on the dominant (quasi-TEM) mode are insignificant and may be ignored when frequency is above 15 GHz. For the higher order modes, resistive film appears to be transparent when film resistance is greater than about 1 kOMEGA, it behaves as a good conductor when film resistance is much smaller than 100 OMEGA, and in between it results in nonlinear (and even oscillatory) higher order modal behaviors. Apparently, due to the increasing field concentration inside the upper dielectric (as suggested by the increasing epsilon(reff)) for a given mode, both the maximum attenuation and the film resistance needed to achieve it increase with frequency and dielectric constant of the upper dielectric layer.
A HEURISTIC RESCHEDULING ALGORITHM FOR COMPUTER-BASED PRODUCTION SCHEDULING SYSTEMS
(1993-08-01)
LI, RK
;
SHYU, YT
;
ADIGA, S
;
交大名義發表
;
工業工程與管理學系
Generation of new production schedules in response to changes that take place on a factory shop-floor is a common requirement in today's complex and flexible manufacturing environment. The current approaches use either a regeneration rescheduling method, which results in unsatisfactory response times or methods that need too much manual intervention for identifying the operations to be changed. We propose a new rescheduling algorithm to address these problems. Our algorithm is based on the construction of a scheduling binary tree and a net change concept adopted from MRP system. It revises schedules by rescheduling only those operations that need to be revised. Our algorithm can be embedded in existing simulation-based scheduling systems or electronic Gantt chart approaches to improve their effectiveness.
EFFECT OF NONPOLAR OPTICAL PHONON-SCATTERING ON FREE-CARRIER ABSORPTION IN HEAVILY-DOPED N-TYPE GERMANIUM
(1993-08-01)
WU, CC
;
LIN, CJ
;
應用數學系
;
電控工程研究所
;
Department of Applied Mathematics
The effect of nonpolar optical phonon scattering on the free-carrier absorption in n-type semiconductors such as germanium has been investigated quantum mechanically in quantizing magnetic fields. It is assumed that the energy band of electrons in semiconductors is nonparabolic and the dominant scattering mechanism for electrons in solids is that of nonpolar optical phonon scattering. When the radiation field is polarized parallel to the magnetic field, the absorption coefficient will be of complex value due to the interaction of the radiation field and the optical phonon field with electrons in semiconductors. Results show that real and imaginary parts of the absorption coefficient oscillate quite considerably with the magnetic field in the high fields for the heavily doped n-type Ge. Both real and imaginary parts of the absorption coefficient appear as positive and negative values when changing the magnetic field. In low magnetic fields, the imaginary part of the absorption coefficient disappears. However, if the density of electrons increases, the imaginary part of the absorption coefficient will increase with the magnetic field in low fields. Moreover, it is also shown that the amplitudes of oscillations for the real and imaginary parts of the absorption coefficient do not vary in a regular trend with the density of electrons.
CHARACTERISTICS OF POLYCRYSTALLINE SILICON THIN-FILM TRANSISTORS WITH THIN OXIDE NITRIDE GATE STRUCTURES
(1993-08-01)
CHENG, HC
;
TAI, YH
;
FENG, MS
;
WANG, JJ
;
材料科學與工程學系
Polycrystalline silicon (poly-Si) thin-film transistors (TFTs) with thin oxide/nitride (O/N) structures as gate dielectrics are fabricated. Various gate dielectrics, i.e., high-temperature thermal oxides with different thicknesses, low-pressure chemical-vapor-deposited silicon nitrides, and different combinations of O/N structures with various thicknesses, are performed to study their effects on poly-Si TFTs. The effective carrier mobility of devices with thin gate oxides is several times larger than of those with thick gate oxides. However, the breakdown voltages of thin gate oxides are too low to satisfy the requirements of TFT applications. Silicon nitrides can be substituted because of the high breakdown voltage and the smooth dielectric/poly-Si interfaces. A problem in adopting silicon nitride is the large interface stress between the silicon nitride and the poly-Si. A thin thermal pad oxide beneath the silicon nitride is therefore grown to reduce the high interface stress. Finally, the equivalent oxide thickness effect of the O/N gate structures on the electrical characteristics of TFTs is systematically investigated.
STUDY OF A LIGHTWAVE SYSTEM CONSISTING ENTIRELY OF ERBIUM-DOPED FIBER
(1993-08-01)
WEN, SF
;
CHI, S
;
光電工程學系
;
電信研究中心
;
Department of Photonics
Investigated is the distributed erbium-doped fiber amplifier of zero dB gain, which has the least required pump power by optimizing the doping density. The total pump power and signal-to-noise ratio of the periodically pumped transmission systems with the unidirectional and bidirectional pumps are obtained.
NOVEL TECHNIQUE FOR SIO2 FORMED BY LIQUID-PHASE DEPOSITION FOR LOW-TEMPERATURE PROCESSED POLYSILICON TFT
(1993-08-01)
YEH, CF
;
LIN, SS
;
CHEN, CL
;
YANG, YC
;
電控工程研究所
A novel technique for SiO2 formation by liquid-phase deposition (LPD) at nearly room temperature for low-temperature processed (LTP) polysilicon thin-film transistor (poly-Si TFT) was developed. LPD-SiO2 film with a lower P-etch rate shows its dense structure. LPD-SiO2 also exhibits good electrical characteristics. LTP poly-Si TFT's with LPD-SiO2, as gate insulator have been fabricated and investigated. Their characteristics exhibit sufficient performance for pixel transistor in liquid crystal display (LCD).
ON THE DESIGN AUTOMATION OF THE MEMORY-BASED VLSI ARCHITECTURES FOR FIR FILTERS
(1993-08-01)
LEE, HR
;
JEN, CW
;
LIU, CM
;
資訊工程學系
;
電子工程學系及電子研究所
The design automation of the memory-based VLSI architectures for FIR filters is investigated. This paper intends to give a thorough discussion about the design space and schemes for this subject. The discussed topics include the conditions leading to efficient memory replacement, the formulation space of FIR filters, the considerations in architecture design, and the methods to evaluate architectures. With the research results of these topics, we present a parameterized memory-based architecture and the hardware-speed evaluation formulae. This architecture is characterized by three parameters into which various memory-based architectures can be generated by substituting different values. The presented formulae are formulated as functions of the three parameters and implementation technology. Using the evaluation formulae and through the parameterized architecture, an area-minimized architecture can be synthesized under a speed specification. Based on these results, we develop an automatic synthesis tool with an illustrating example.
ADAPTIVE-CONTROL OF NONLINEAR CONTINUOUS-TIME SYSTEMS USING NEURAL NETWORKS GENERAL RELATIVE DEGREE AND MIMO CASES
(1993-08-01)
LIU, CC
;
CHEN, FC
;
交大名義發表
;
電控工程研究所
;
National Chiao Tung University
Multilayer neural networks are used in a non-linear adaptive control problem. The plant is an unknown feedback linearizable continuous-time system with relative degree greater-than-or-equal-to 1. The single-input/single-output system is studied first and then the methodology is extended to control square multi-input/multi-output systems. The control objective is for the plant to track a reference trajectory, and the control law is defined in terms of the outputs of the neural networks. The parameters of the networks are updated on-line according to an augmented tracking error and the network derivatives. A local convergence theorem is given on the convergence of the tracking error. This control algorithm is applied to control a two-input/two-output relative-degree-two system.
EFFECT OF ANNEALING ON ELECTRICAL AND OPTICAL-PROPERTIES OF RF MAGNETRON-SPUTTERED INDIUM TIN OXIDE-FILMS
(1993-08-01)
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, 90wt%In2O3-10wt%SnO2) films of approximately mum thick have been deposited on glass substrates by radio-frequency (RF) magnetron sputtering. The effect of post-deposition heat treatment on the electrical and optical properties of ITO films are investigated. Annealing of ITO-coated substrates at a temperature of 350-550-degrees-C for 2 h in air causes the ITO layers to crystallize and grains to grow. Tin atoms are activated after annealing and behave as effective donors. The electrical resistivity of ITO film decreases by more than two orders of the magnitude after annealing. The infrared reflectance increases as the annealing temperature is raised. An infrared reflectance of approximately 60% (at 5 mum) is obtained for the 550-degrees-C-annealed sample. Several material parameters, such as the effective band gap and the refractive index, have been derived and discussed.