Browsing by Issue Date, starting with "2004-02-01"

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The effectiveness of randomized complete block design
(2004-02-01)
Shieh, G
;
Jan, SL
;
管理科學系
;
Department of Management Science
This paper examines the relative efficiency of randomized complete block design as compared with that of completely randomized design. The most widely used measure of relative efficiency considers only the error variances of the two designs, therefore it does not provide the complete information concerning the sensitivity of the experiment in the final results. We study three alternative criteria related to the sensitivity issue and design planning consideration. The proposed relative measures employ the p-value, Scheffe confidence interval estimation and power of both designs. The distinct feature of this study is the focus on the estimated relative efficiency measures and their relation with the coefficient of partial determination between responses and block effects, given that treatment effects are present in the models. Furthermore, informative visual representations and numerical assessments of various aspects of their properties are also presented.
Thermally activated diffusion observed by in situ reflection high energy electron diffraction intensity monitoring on interrupted SrTiO3 homoepitaxial growth
(2004-02-01)
Wang, TC
;
Juang, JY
;
Wu, KH
;
Uen, TM
;
Gou, YS
The reflection high energy electron diffraction (RHEED) intensity is reported following a quadratic power law dependence on annealing time for interrupted laser ablation-grown strontium titanate films. The activation energy of 1.0eV can further be obtained from the diffusion Arrhenius plot by assuming a direct proportionality between the RHEED intensity and the diffusion length.
Specific interactions in miscible polymer blends of poly(2-hydroxypropyl methacrylate) with polyvinylpyrrolidone
(2004-02-01)
Kuo, SW
;
Shih, CC
;
Shieh, JS
;
Chang, FC
;
應用化學系
The miscibility behaviour and hydrogen-bonding interaction in blends of poly(2-hydroxypropyl methacrylate) (PHPMA) with polyvinylpyrrolidone (PVP) were characterized using differential scanning calorimetry and Fourier-transform infrared spectra. This polymer blend was miscible over the whole composition range and an unusually large positive deviation of T-g from the linearity rule was observed, indicating strong hydrogen bonding between the hydroxyl group of PHPMA and the carbonyl group of PVP. Infrared spectroscopic analysis provided positive evidence for the intra-molecular hydrogen bonding of PHPMA and inter-molecular hydrogen bonding between PHPMA and PVP at various compositions and temperatures. Furthermore, equilibrium constants and enthalpies of self-association and inter-association between functional groups in the blend of PHPMA and PVP were calculated to explain the results. (C) 2004 Society of Chemical Industry.
據說詩是毒品
(2004-02-01)
管管
Calibrations of phase modulation amplitude of photoelastic modulator
(2004-02-01)
Wang, MW
;
Chao, YF
;
Leou, KC
;
Tsai, FH
;
Lin, TL
A multiple harmonic intensity ratio technique is proposed for calibrating the modulation amplitude (Delta(0)) of a photoelastic modulator (PEM). A data acquisition system is utilized to investigate the frequency response of this technique. Delta(0) determined by this technique is independent of frequency, which is proved using the reflection and transmission setups. In addition to confirm our calibration using the digitized oscilloscope waveform, we also obtain a set of ellipsometric parameters under various values of Delta(0) before and after calibration. We also introduce a correction factor to correct the effect caused by the shift of the modulation amplitude in the process of etching. An optical thick film is used to calibrate Delta(0) using PEM ellipsometry, and its refractive index and extinction coefficient are also obtained in etching. Finally, we suggest the use of the traces of the ellipsometric parameters under various thicknesses for monitoring instead of calculating the thickness in real time.
Real-time data access on HSDPA for WCDMA
(2004-02-01)
Wan, CS
;
Shih, WK
;
Chang, RC
;
資訊工程學系
;
Department of Computer Science
This paper presents new High Speed Downlink Shared Channel (HS-DSCH) code management schemes on High Speed Downlink Packet Access (HSDPA) for IP-based multimedia provisioning. The proposed management schemes simplify HS-DSCH code allocation while simultaneously increasing HS-DSCH code utilization. Applying the code management schemes, furthermore, we implement two scheduling algorithms for real-time packets to guarantee the quality-of-service (QoS) requirement. The Real-Time Code Allocation (RTCA) algorithm applies the functionalities of the radio management framework to decide the admission for a new real-time service. Once a new real-time session is established, RTCA allocates HS-DSCH codes to that session such that all real-time packets in the session are scheduled before their related deadlines. Based on the RTCA algorithm, the Real-Time Code Sharing (RTCS) algorithm implements the Early-Deadline-First (EDF) scheme for the schedulability analysis, increasing the schedulable probability for the real-time sessions and thus to improve the utilization of HS-DSCH codes. Experimental results show that RTCS outperforms RTCA in terms of packet drop rates, HS-DSCH code blocking rates and the number of code-domain reassignments.
Purification of human haptoglobin 1-1, 2-1, and 2-2 using monoclonal antibody affinity chromatography
(2004-02-01)
Tseng, CF
;
Huang, HY
;
Yang, YT
;
Mao, SJT
;
生物科技學系
Similar to blood type, human plasma haptoglobin (Hp) is classified as 3 phenotypes: Hp 1-1, 2-1, or 2-2. The structural and functional relationship between the phenotypes, however, has not been studied in detail due to the complicated and difficult isolation procedures. This report provides a simple protocol that can be used to purify each Hp, phenotype. Plasma was first passed through an affinity column coupled with a high affinity Hp monoclonal antibody. The bound material was washed with a buffer containing 0.2 M NaCl and 0.02 M phosphate, pH 7.4, eluted at pH 11, and collected in tubes containing 1 M Tris-HCl, pH 6.8. The crude Hp fraction was then chromatographed on a HPLC Superose 12 column in 0.05 M ammonium bicarbonate at a flow rate of 0.5ml/min. The homogeneity of purified Hp 1-1, 2-1, or 2-2 was greater than 95% as judged by SDS-polyacrylamide gel electrophoresis. Essentially, each Hp isolated was not contaminated with hemoglobin and apolipoprotein A-I as that reported from the other methods, and was able to bind hemoglobin. Neuraminidase treatment demonstrated that the purified Hp possessed a carbohydrate moiety, while Western blot analysis confirmed alpha and beta chains corresponding to each Hp 1-1, 2-1, and 2-2 phenotype. The procedures described here represent a significant improvement in current purification methods for the isolation of Hp phenotypes. Circular dichroic spectra showed that the alpha-helical content of Hp 1-1 (29%) was higher than that of Hp 2-1 (22%), and 2-2 (21%). The structural difference with respect to its clinical relevance is discussed. (C) 2003 Elsevier Inc. All rights reserved.
Magnetic circular dichroism in Fe 2p resonant photoemission of magnetite
(2004-02-01)
Chen, J
;
Huang, DJ
;
Tanaka, A
;
Chang, CF
;
Chung, SC
Measurements of magnetic circular dichroism in Fe 2p resonant photoemission and calculations based on a full-multiplet cluster model reveal the parameters of the electronic structure of Fe3O4. We obtained on-site Coulomb energy U-dd of 3d electrons, charge-transfer energy Delta which is defined as the energy required to transfer an electron from O 2p to Fe 3d, and the hybridization strength between Fe 3d and O 2p at different Fe ion sites of Fe3O4 by analyzing the data of magnetic circular dichroism. The charge-transfer energy of Fe3+ ions was found to be significantly smaller than that of Fe2+ ions. We determined the energy positions of the low-lying multiplets of each Fe ion site. These energy positions for Fe3+ ion sites are 1.5-2.5 eV higher than those obtained from band-structure calculations. Our calculations also show that the photoemission spectral weight in binding energy bigger than 10 eV is substantial, in contrast to the results of band-structure calculations. Our findings conclude that Fe3O4 is a system with strong electron-electron interactions.
Drifting diffusion on a circle as continuous limit of a multiurn Ehrenfest model
(2004-02-01)
Luan, PG
;
Kao, YM
;
物理研究所
;
Institute of Physics
We study the continuous limit of a multibox Erhenfest urn model proposed before by the authors. The evolution of the resulting continuous system is governed by a differential equation, which describes a diffusion process on a circle with a nonzero drifting velocity. The short time behavior of this diffusion process is obtained directly by solving the equation, while the long time behavior is derived using the Poisson summation formula. They reproduce the previous results in the large M (number of boxes) limit. We also discuss the connection between this diffusion equation and the Schrodinger equation of some quantum mechanical problems.
Amplitude-squeezed fiber-Bragg-grating solitons
(2004-02-01)
Lee, RK
;
Lai, Y
;
光電工程研究所
;
Institute of EO Enginerring
Quantum fluctuations of optical fiber-Bragg-grating solitons are investigated numerically by the back-propagation method. It is found that the band-gap effects of the grating act as a nonlinear filter and cause the soliton to be amplitude squeezed. The squeezing ratio saturates after a certain grating length and the optimal squeezing ratio occurs when the pulse energy is slightly above the fundamental soliton energy.
An automatic transmission for bicycles: a simulation
(2004-02-01)
Chien, HC
;
Tseng, CH
;
機械工程學系
;
Department of Mechanical Engineering
A new design of an automatic transmission for bicycles was simulated. A sensitivity analysis found most environmental and bicycle variables had little effect but cycling velocity was very important while pedal rpm and gradient of the ground had some effect. The new design transmission therefore emphasizes velocity, pedal rpm and gradient of the ground when selecting the optimum gear ratios. Since the comfortable pedal rpm differs from cyclist to cyclist, this new automatic transmission continuously measures the pedal rpm and calculates an average to efficiently learn the cycling habit of different cyclists.
Design and performance evaluation of an improved TCP congestion avoidance scheme
(2004-02-01)
Chan, YC
;
Chan, CT
;
Chen, YC
;
資訊工程學系
;
Department of Computer Science
TCP Vegas detects network congestion in its early stage and successfully prevents the periodic packet loss that usually occurs in traditional schemes. It has been demonstrated that TCP Vegas achieves a much higher throughput than TCP Reno. However, TCP Vegas cannot prevent unnecessary throughput degradation when congestion occurs on the backward path. A router-based congestion avoidance scheme for TCP Vegas is proposed. By distinguishing whether or not congestion occurs in the forward path, it significantly improves the connection throughput when the backward path is congested.
Poincare cycle of an Ehrenfest multiurn model in a one-dimensional ring
(2004-02-01)
Kao, YM
;
物理研究所
;
Institute of Physics
We study an Ehrenfest multiurn model of a one-dimensional ring, generalizing the directed transport in the previous model to arbitrary transports. We analytically study the evolution of the system and calculate the Poincare cycle for given transport probabilities. The result shows that the average number of balls in an urn evolves according to the transport probability, but the Poincare cycle is only related to the initial configuration.
Leakage and breakdown mechanisms of Cu comb capacitors with bilayer-structured alpha-SiCN/alpha-SiC Cu-cap barriers
(2004-02-01)
Chiang, CC
;
Ko, IH
;
Chen, MC
;
Wu, ZC
;
Lu, YC
This work investigates the leakage and breakdown mechanisms in copper (Cu) comb capacitors with carbon-doped low-k plasma-enhanced chemical vapor deposited organosilicate glass (OSG; k = 3) as the intermetal dielectric and an alpha-SiCN (k = 5)/ alpha-SiC (k = 4) bilayer-structured dielectric film as the Cu-cap barrier. The leakage mechanism between Cu lines is dependent on the thickness ratio of the alpha-SiCN/alpha-SiC bilayer barrier. Using an alpha-SiCN/alpha-SiC bilayer barrier of 40 nm/10 nm or 30 nm/20 nm bilayer thickness, the increased leakage current (Frenkel-Poole emission) between Cu lines is attributed to the large number of interfacial defects, such as cracks, voids, traps or dangling bonds at the alpha-SiC/OSG interface, which are generated by the larger tensile force of the thicker alpha-SiC film. The Cu comb capacitor with an alpha-SiCN (50 nm)/alpha-SiC (2 nm) bilayer barrier exhibits a much smaller leakage current. The breakdown field and time-dependent dielectric breakdown lifetime of the Cu comb capacitor reveal little dependence on the thickness ratio of the alpha-SiCN/alpha-SiC bilayer barrier, and the observed breakdown of the Cu comb capacitor is presumably due to dielectric breakdown of the bulk OSG layer. (C) 2004 The Electrochemical Society.
Selective growth of ZnO nanorods on pre-coated ZnO buffer layer
(2004-02-01)
Hsu, HC
;
Tseng, YK
;
Cheng, HM
;
Kuo, JH
;
Hsieh, WF
Hexagonal ZnO nanorods have been selectively synthesized via vapor-solid process without gold catalysis on. a precoated ZnO buffer layer. The presence of nanometer-sized pits or hills on the surface of ZnO buffer layer provides nucleation sites to which the zinc vapor is transferred and condensed. Followed by immediate oxidation the ZnO nanorods were grown on the. buffer layer. Contrarily, the SEM images hardly show growth of irregular ZnO nanometer-sized products on the bare sapphire substrate. Besides a strong ultra-violet emission at 3.26 eV observed at room temperature, the coupling strength of the radiative transition to LO-phonon polarization field was deduced in use of the Huang-Rhys factor. from low temperature photoluminescence spectra to show that single crystalline ZnO nanorods. (C) 2003 Elsevier B.V. All rights reserved.
Contour of the attenuated length of an evanescent wave at constant frequency within a band gap of photonic crystal
(2004-02-01)
Hsue, YC
;
Yang, TJ
;
電子物理學系
;
Department of Electrophysics
The plane wave method is normally applied to determine the eigenfrequency of a two-dimensional (2D) photonic crystal. A slight change to this eigenvalue equation makes the wave number its eigenvalue providing a direct means to determine the attenuated length of the evanescent modes at the frequency within the photonic band gap. The contour of the length of attenuation of the evanescent modes in a square lattice can be determined using the proposed wave number eigenvalue equation. The wave number eigenvalue equation for the two-dimensional (3D) photonic crystal can also be obtained using a derivation similar to that for the 2D photonic crystal. Possible applications of the proposed calculation-method are presented. (C) 2003 Elsevier Ltd. All rights reserved.
Stability of the anisotropic brane cosmology
(2004-02-01)
Chen, CM
;
Kao, WF
;
物理研究所
;
Institute of Physics
The stability of the Bianchi type I anisotropic brane cosmology is analyzed in this paper. We also study the effects of the brane solution by comparing the models on the 3-brane and the models in the conventional Einstein space. The analysis is presented for two different models: one with a perfect fluid and the other with a dilaton field. It is shown that the anisotropic expansion is smeared out dynamically for both theories in the large time limit, independent of the models of different types of matter. The initial states are, however, dramatically different. A primordial anisotropic expansion will grow for the conventional Einstein's theory. On the other hand, it is shown that the initial state is highly isotropic for the brane universe, except for a very particular case. Moreover, it is also shown that the Bianchi type I anisotropic cosmology is stable against any anisotropic perturbation for both theories in the large time limit.
A novel prosodic-information synthesizer based on recurrent fuzzy neural network for the Chinese TTS system
(2004-02-01)
Lin, CT
;
Wu, RC
;
Chang, JY
;
Liang, SF
;
電控工程研究所
In this paper, a new technique for the Chinese text-to-speech (TTS) system is proposed. Our major effort focuses on the prosodic information generation. New methodologies for constructing fuzzy rules in a prosodic model simulating human's pronouncing rules are developed. The proposed Recurrent Fuzzy Neural Network (RFNN) is a multilayer recurrent neural network (RNN) which integrates a Self-constructing Neural Fuzzy Inference Network (SONFIN) into a recurrent connectionist structure. The RFNN can be functionally divided into two,parts. The first part adopts the SONFIN as a prosodic model to explore the relationship between high-level linguistic features and prosodic information based on fuzzy inference rules. As compared to conventional neural networks, the SONFIN can always construct itself with an economic network size in high learning speed. The second part employs a five-layer network to generate all prosodic parameters by directly using the prosodic fuzzy rules inferred from the first part as well as other important features of syllables. The TTS system combined with the proposed method can behave not only sandhi rules but also the other prosodic phenomena existing in the traditional TTS systems. Moreover, the proposed scheme can even find out some new rules about prosodic phrase structure. The performance of the proposed RFNN-based prosodic model is verified by imbedding it into a Chinese TTS system with a Chinese monosyllable database based on the time-domain pitch synchronous overlap add (TD-PSOLA) method. Our experimental results show that the proposed RFNN can generate proper prosodic parameters including pitch means, pitch shapes, maximum energy levels, syllable duration, and pause duration. Some synthetic sounds are on-line available for demonstration.
An ordinal optimization theory-based algorithm for solving the optimal power flow problem with discrete control variables
(2004-02-01)
Lin, SY
;
Ho, YC
;
Lin, CH
;
電控工程研究所
;
Institute of Electrical and Control Engineering
The optimal power flow (OPF) problem with discrete control variables is an NP-hard problem in its exact formulation. To cope with the immense computational-difficulty of this problem, we propose an ordinal optimization theory-based algorithm to solve for a good enough solution with high probability. Aiming for hard optimization problems, the ordinal optimization theory, in contrast to heuristic methods, guarantee to provide a top n% solution among all with probability more than 0.95. The approach of our ordinal optimization theory-based algorithm consists of three stages. First, select heuristically a large set of candidate solutions. Then, use a simplified model to select a subset of most promising solutions. Finally, evaluate the candidate promising-solutions of the reduced subset using the exact model. We have demonstrated the computational efficiency of our algorithm and the quality of the obtained solution by comparing with the competing methods and the conventional approach through simulations.
Improved characteristics of ultrathin CeO2 by using postnitridation annealing
(2004-02-01)
Wang, JC
;
Hung, YP
;
Lee, CL
;
Lei, TF
;
電子工程學系及電子研究所
This work demonstrates the improved characteristics of an ultrathin CeO2 dielectric by using the post-N2O plasma treatment with additional rapid thermal N-2 annealing. The CeO2 after the treatment exhibits superior characteristics such as a small effective oxide thickness (similar to2.25 nm), a low leakage current (5.4 x 10(-4) A/cm(2)), a high breakdown electric field (-24 MV/cm), a long projected 10 yr lifetime (-12 MV/cm), a small capacitance-voltage hysteresis (25 mV), and a high barrier height for Frenkel-Poole emission (0.55 eV). These good properties are attributed to the nitrogen incorporation into the dielectric to eliminate the traps after annealing. The postnitridation annealing appears to be a very useful treatment for future ultrathin metal-oxide gate dielectrics. (C) 2004 The Electrochemical Society.