Browsing by Issue Date, starting with "1991-10-07"

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A SIMULATION STUDY ON THE SERVICE STRATEGIES FOR PACKET VOICE COMMUNICATION-NETWORKS
(1991-10-07)
CHANG, CJ
;
WONG, JW
;
CHIU, JH
;
電信工程研究所
;
電信研究中心
Two service strategies for packet voice communication networks are studied by simulation in this paper. The first one is the first-packet-first-priority (FPFP) service strategy. This strategy gives the packet firstly generated in a talkspurt the first priority. The second one is the maximum-delay-first-serve (MDFS) service strategy. This strategy gives the more delayed voice packet the higher priority. The FPFP and the MDFS strategies are proposed in order to match with the null timing information (NTI) and the complete timing information (CTI) reassembly schemes adopted at a packet voice receiver in Barberis and Pazzaglia's "Analysis and optimal design of a packet voice receiver", respectively, to improve the network performance. These two strategies are also compared with the simple first-in-first-out (FIFO) service strategy. The results show that the MDFS strategy has the smallest delay variation and loss rate of voice packet, the FIFO strategy has the middle values, while the FPFP strategy has the maximum.
A SIMULATION STUDY ON THE SERVICE STRATEGIES FOR PACKET VOICE COMMUNICATION-NETWORKS
(1991-10-07)
CHANG, CJ
;
WONG, JW
;
CHIU, JH
;
電信研究中心
;
Center for Telecommunications Research
Two service strategies for packet voice communication networks are studied by simulation in this paper. The first one is the first-packet-first-priority (FPFP) service strategy. This strategy gives the packet firstly generated in a talkspurt the first priority. The second one is the maximum-delay-first-serve (MDFS) service strategy. This strategy gives the more delayed voice packet the higher priority. The FPFP and the MDFS strategies are proposed in order to match with the null timing information (NTI) and the complete timing information (CTI) reassembly schemes adopted at a packet voice receiver in Barberis and Pazzaglia's "Analysis and optimal design of a packet voice receiver", respectively, to improve the network performance. These two strategies are also compared with the simple first-in-first-out (FIFO) service strategy. The results show that the MDFS strategy has the smallest delay variation and loss rate of voice packet, the FIFO strategy has the middle values, while the FPFP strategy has the maximum.
GAUGE-SYMMETRY IN SPINOR SPACE
(1991-10-10)
KAO, WF
;
交大名義發表
;
電子物理學系
;
National Chiao Tung University
;
Department of Electrophysics
It is possible to generalize the global similarity transformation in spinor space to a U4 gauge transformation. This gauge transformation is commute with Lorentz transformation if Lorentz transformation is defined in a gauge-covariant way which will be described in this letter. Moreover, this theory is invariant under the conventional U(1) gauge symmetry. Possible implications are also discussed.
GAUGE-SYMMETRY IN SPINOR SPACE
(1991-10-10)
KAO, WF
;
電子物理學系
;
Department of Electrophysics
It is possible to generalize the global similarity transformation in spinor space to a U4 gauge transformation. This gauge transformation is commute with Lorentz transformation if Lorentz transformation is defined in a gauge-covariant way which will be described in this letter. Moreover, this theory is invariant under the conventional U(1) gauge symmetry. Possible implications are also discussed.
TRANSIENT-RESPONSE OF A THRESHOLDLESS MICRODROPLET DYE-LASER
(1991-10-15)
LIN, KH
;
HSIEH, WF
;
光電工程研究所
;
Institute of EO Enginerring
Lasing in a cavity formed by a dye-doped micrometer-sized liquid droplet showed a new thresholdless steady-state behavior and a time-dependent response. The thresholdless behavior is associated with enhancement and inhibition of the spontaneous emission. The time-dependent response is related to various quality factors of the cavity modes and was determined to be 8 x 10(8).
EXCITON BINDING-ENERGY IN A GAAS/ALXGA1-XAS QUANTUM-WELL WITH UNIFORM ELECTRIC-FIELD
(1991-10-15)
CHUU, DS
;
SHIH, YT
;
電子物理學系
;
Department of Electrophysics
The effects of a uniform electric field on the binding energies of excitons and the subband energies in a GaAs/AlxGa1-xAs quantum well are studied by a perturbative variational approach. Our calculation is based on an effective-width infinite-well model. The effective-mass mismatch is also taken into account. Our results show that the electric field causes a large shift of the subband energy and exciton peak position. The calculated results are compared with the data observed from an optical-absorption experiment. Satisfactory agreement is obtained.
SELF-INDUCED TRANSPARENCY IN A DISPERSIVE AND NONLINEAR KERR HOST MEDIUM
(1991-10-15)
WANG, TY
;
CHI, S
;
光電工程學系
;
電信研究中心
;
Department of Photonics
A steady-state solution that describes pulse propagation in inhomogeneously broadening two-level atoms embedded in a dispersive and nonlinear Kerr lossless host medium has been found. The solution is of an unchirped hyperbolic-secant form with a linear spatial phase delay. The features of the solution are (i) the group velocity, the amplitude, and the width of the pulse are uniquely determined for given parameters of the medium and the carrier frequency; (ii) the group velocity is independent of the density of the resonant atoms; and (iii) the solution can exist in the positive dispersion region.
TRANSIENT-RESPONSE OF A THRESHOLDLESS MICRODROPLET DYE-LASER
(1991-10-15)
LIN, KH
;
HSIEH, WF
;
交大名義發表
;
光電工程學系
;
National Chiao Tung University
Lasing in a cavity formed by a dye-doped micrometer-sized liquid droplet showed a new thresholdless steady-state behavior and a time-dependent response. The thresholdless behavior is associated with enhancement and inhibition of the spontaneous emission. The time-dependent response is related to various quality factors of the cavity modes and was determined to be 8 x 10(8).
談「我的五個情人」
(1991-10-31)
管管
談「我的五個情人」
(1991-10-31)
管管
談「我的五個情人」
(1991-10-31)
管管
STATISTICAL LINEARIZATION FOR MULTIINPUT MULTIOUTPUT NONLINEARITIES
(1991-11-01)
LIN, CA
;
CHENG, VHL
;
電控工程研究所
;
Institute of Electrical and Control Engineering
STATISTICAL LINEARIZATION FOR MULTIINPUT MULTIOUTPUT NONLINEARITIES
(1991-11-01)
LIN, CA
;
CHENG, VHL
;
電控工程研究所
;
Institute of Electrical and Control Engineering
INTERACTING-BOSON-FERMION-APPROXIMATION DESCRIPTION OF NEGATIVE-PARITY STATES IN EVEN-ODD YB ISOTOPES
(1991-11-01)
HSIEH, ST
;
CHUU, DS
;
電子物理學系
;
Department of Electrophysics
The negative-parity energy levels of the even-odd Yb isotopes, 163Yb, 165Yb, Yb-169, Yb-171, and Yb-173, are studied systematically within the framework of the extended interacting-boson-fermion-approximation (IBFA) model in which one odd fermion is couplied with a boson core. The boson core is described with the IBA model but allowing one boson to break into a quasifermion pair. The odd fermion is assumed to be in one of the f7/2 and p3/2 single-particle orbitals while the fermion pair is allowed to occupy the single-particle orbit i13/2. It was found that the negative-parity energy levels of these even-odd Yb isotopes and the values of transition quadrupole moments for the ground-state rotational band of Yb-173 can be reproduced in fairly good agreement with the observed data.
PRECISE DETERMINATION OF ALUMINUM CONTENT IN ALGAAS
(1991-11-01)
CHANG, KH
;
LEE, CP
;
WU, JS
;
LIU, DG
;
LIOU, DC
The Al composition of AlGaAs has been determined by four methods: high-resolution transmission electron microscopy (HRTEM), reflection high-energy electron diffraction (RHEED), photoluminescence (PL), and double-crystal x-ray diffraction (DCXRD). HRTEM is direct and the most accurate method because it does not involve any formula or extrapolation. Using the result obtained from HRTEM as a standard, we have calibrated the results from other methods. RHEED intensity oscillation is found to be accurate and reliable, if the growth conditions are correctly chosen. Comparing the PL results with those determined from HRTEM and RHEED, we suggest three formulas to determine the Al contents at different temperatures. We also proposed a polynomial to determine the Al concentration using the DCXRD measurement.
BEAM PROPAGATION METHOD ANALYSIS OF TRANSVERSE-ELECTRIC WAVES PROPAGATING IN A NONLINEAR TAPERED PLANAR WAVE-GUIDE
(1991-11-01)
SHI, TT
;
CHI, S
;
光電工程學系
;
電信研究中心
;
Department of Photonics
The propagation of TE-polarized guided waves in a nonlinear tapered waveguide is studied. The incident fields are chosen from the stable branches of the nonlinear dispersion curve in its uniform section. The propagations of the field in both directions are calculated by the beam-propagation method. Wave propagation in the tapered waveguide is discussed in terms of the nonlinear dispersion curves of the waveguide. Depending on the intensity, the field can radiate as a spatial soliton or it can have an abrupt transition between the guided mode and the surface polariton. The wave propagation of an incident field that is composed of a dominant TE0 wave and a small TE1 wave is investigated. Finally, using a property of this wave propagation, we present a new device for continuous signal routing.
FAULT-TOLERANT DECENTRALIZED COMMIT PROTOCOLS
(1991-11-01)
YUAN, SM
;
AGRAWALA, AK
;
資訊工程學系
;
Department of Computer Science
PHASE-SEPARATION IN AN FE-23.0MN-10.6AL-6.4 NI ORDERED ALLOY
(1991-11-01)
LIN, YL
;
CHOU, CP
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
DIRECT EVIDENCE OF GATE OXIDE THICKNESS INCREASE IN TUNGSTEN POLYCIDE PROCESSES
(1991-11-01)
HSU, SL
;
LIU, LM
;
LIN, MS
;
CHANG, CY
;
電子工程學系及電子研究所
The increase of the "effective" gate oxide thickness for W-polycide processes is studied. The samples with as-deposited and annealed W polycide are analyzed by secondary ion mass spectrometry, transmission electron microscopy (TEM), and high-frequency CV measurements. The TEM cross section shows that the gate oxide thicknesses are approximately 244 and approximately 285 angstrom for as-deposited and 1000-degrees-C annealed samples, respectively. The TEM results agree with that from CV measurements. The TEM analyses provide a direct physical evidence of an additional oxide thickness (approximately 41 angstrom) during the W-polycide annealing.
EXISTENCE AND MULTIPLICITY OF POSITIVE RADIAL SOLUTIONS FOR SEMILINEAR ELLIPTIC-EQUATIONS IN ANNULAR DOMAINS
(1991-11-01)
LIN, SS
;
PAI, FM
;
應用數學系
;
Department of Applied Mathematics
The existence and multiplicity of positive radial solutions of equation DELTA-u + f(u) = 0 is studied in annular domains in R(n), n greater-than-or-equal-to 2. It is proven that if f(0) greater-than-or-equal-to 0,f is somewhere negative in (0, infinity) and superlinear at infinity, then there is a large positive radial solutions on all annuli. If f(0) < 0 and satisfies certain conditions, then the equation has no solution if the annuli are too wide. Multiplicity results are also obtained when f has many humps with positive areas.