Browsing by Issue Date, starting with "2002-03-16"

Now showing 1 - 20 of 74822

A fuzzy seasonal ARIMA model for forecasting
(2002-03-16)
Tseng, FM
;
Tzeng, GH
;
科技管理研究所
;
Institute of Management of Technology
This paper proposes a fuzzy seasonal ARIMA (FSARIMA) forecasting model, which combines the advantages of the seasonal time series ARIMA (SARIMA) model and the fuzzy regression model. It is used to forecast two seasonal time series data of the total production value of the Taiwan machinery industry and the soft drink time series. The intention of this paper is,to provide business which are affected by diversified management with a new method to conduct short-term forecasting. This model includes both interval models with interval parameters and the possible distribution of future value. Based on the results of practical application, it can be shown that this model makes good forecasts and is realistic. Furthermore, this model makes it possible for decision makers to forecast the best and worst estimates based on fewer observations than the SARIMA model. (C) 2002 Elsevier Science B.V. All rights reserved.
Layered silicates/fluorinated polyimide nanocomposites for advanced dielectric materials applications
(2002-03-18)
Jiang, LY
;
Leu, CM
;
Wei, KH
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材料科學與工程學系
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Department of Materials Science and Engineering
Structured silicates/fluorinated polyimide nanocomposites display excellent water-absorption retardation behavior. This leads to lower leakage-current densities and lower dielectric constants under higher humidity conditions than those of the pristine fluorinated polyimides. Part of the chemical structure of the lavered silicate used in this work is shown in the Figure.
CPn model on fuzzy sphere
(2002-03-18)
Chan, CT
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Chen, CM
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Lin, FL
;
Yang, HS
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電子物理學系
We construct the CPn model on fuzzy sphere. The Bogomolny bound is saturated by (anti-)self-dual solitons and the general solutions of BPS equation are constructed. The dimension of moduli space describing the BPS solution on fuzzy sphere is exactly the same as that of the commutative sphere or the (noncommutative) plane. We show that in the soliton backgrounds, the number of zero modes of Dirac operator on fuzzy sphere, Atiyah-Singer index, is exactly given by the topological charge of the background solitons. (C) 2002 Elsevier Science B.V. All rights reserved.
Real index-guided InGaAlP red lasers with buried tunnel junctions
(2002-03-18)
Lu, TC
;
Shieh, HM
;
Wang, SC
;
光電工程學系
;
Department of Photonics
Real index-guided buried ridge InGaAlP 650 nm band lasers with p(+)-n(+) buried tunnel junctions are demonstrated. Located on top of the buried ridges, the tunnel junctions, made of InGaAs/GaAs superlattices with modulation doping, were introduced as the current injection window areas. The large band gap In0.5Al0.5P layers were directly regrown around the ridges using metalorganic chemical vapor deposition to serve as the current blocking layers. Real index optical waveguiding in the lateral direction was also provided by the smaller refractive index of In0.5Al0.5P layers. The lasers showed lower threshold current and higher slope efficiency compared to conventional complex index-guided InGaAlP lasers with GaAs current blocking layers, and had low internal loss of about 5.4 cm(-1). (C) 2002 American Institute of Physics.
Effect of annealing temperature on physical and electrical properties of Bi3.25La0.75Ti3O12 thin films on Al2O3-buffered Si
(2002-03-18)
Sun, CL
;
Chen, SY
;
Chen, SB
;
Chin, A
;
材料科學與工程學系
The effect of annealing temperature, especially at high temperatures, on the physical and electrical properties of Bi3.25La0.75Ti3O12 (BLT) thin films on Al2O3 (10 nm)/Si has been investigated. The width of memory window in capacitance-voltage curves for BLT/Al2O3/Si capacitors annealed at temperature range of 700 degreesC-950 degreesC increases with increasing annealing temperature. At the highest annealing temperature of 950 degreesC, a large ferroelectric memory window of 13 V is obtained under +/-15 V sweep voltage, and this large ferroelectric memory window should be related to the reduced leakage current. Owing to the excellent electrical properties, the high-temperature stable BLT/Al2O3/Si capacitor is compatible with current very large scale integrated technology process. (C) 2002 American Institute of Physics.
Expression, characterization, and purification of recombinant porcine lactoferrin in Pichia pastoris
(2002-03-20)
Mao, SJT
;
Wang, SH
;
生物科技學系
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Department of Biological Science and Technology
Suppressing tumor progression and inducing cell differentiation on prostate cancer cells by human psychosomatic power
(2002-03-20)
Yu, T
;
Hwang, ML
;
Tsai, WL
;
Sheu, JJC
;
應用化學系
Expression, characterization, and purification of recombinant porcine lactoferrin in Pichia pastoris
(2002-03-20)
Mao, SJT
;
Wang, SH
;
生物科技學系
;
Department of Biological Science and Technology
Exact solution of inventory replenishment policy for a linear trend in demand - two-equation model
(2002-03-21)
Lo, WY
;
Tsai, CH
;
Li, RK
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
This study presents a model for obtaining the exact optimal solution of inventory replenishment policy problem. The proposed model, called the "two-equation model", includes two governing equations and a time-frequency algorithm: the first equation determines the optimal replenishment times for a specified number of replenishments; the second equation determines the optimal number of replenishments. The time-frequency algorithm includes two main procedures to solve the first and second equations. In contrast to many approximation approaches, this model exactly solves the first equation, a simultaneous non-linear equations system using a generalized matrix-based solver. This study also examines the classical no-shortage inventory replenishment policy for linear increasing and decreasing trend demand. According to these results, the solution given by the two-equation model is an exact solution. (C) 2002 Elsevier Science B.V. All rights reserved.
Analyses of beta-lactoglobulin as a thermal marker in raw and commercially processed hulk using a native gel electrophoresis and circular dichroic spectrum
(2002-03-22)
Chen, WL
;
Mao, SJT
;
生物科技學系
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Department of Biological Science and Technology
Chaos, chaos control and synchronization of a gyrostat system
(2002-03-28)
Ge, ZM
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Lin, TN
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機械工程學系
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Department of Mechanical Engineering
The dynamic behavior of a gyrostat system subjected to external disturbance is studied in this paper, By applying numerical results, phase diagrams, power spectrum, period-T maps, and Lyapunov exponents are presented to observe periodic and choatic motions. The effect of the parameters changed in the system can be found in the bifurcation and parametric diagrams. For global analysis, the basins of attraction of each attractor of the system are located by employing the modified interpolated cell mapping (MICM) method. Several methods, the delayed feedback control, the addition of constant torque, the addition of periodic force, the addition of periodic impulse torque, injection of dither signal control, adaptive control algorithm (ACA) control and bang-bang control are used to control chaos effectively. Finally, synchronization of chaos in the gyrostat system is studied. (C) 2002 Elsevier Science Ltd.
Miscibility behavior and specific interaction of phenolic resin with poly(acetoxystyrene) blends
(2002-03-28)
Kuo, SW
;
Chang, FC
;
應用化學系
;
Department of Applied Chemistry
The miscibility behavior and specific interaction of phenolic resin with poly(acetoxystyrene) (PAS) blends were examined using differential scanning calorimetry (DSC), fourier-transform infrared (FT-IR) spectroscopy and solid-state NMR. This phenolic/PAS blend is fully miscible, as indicated by a single glass-transition temperature, due to the formation of inter-hydrogen bonding between the hydroxyl group of the phenolic resin and the carbonyl group of PAS. The DSC study indicates that this phase-separation exothermic peak area is closely related to the interaction between the components. Furthermore, C-13 solid-state NMR and FT-IR spectroscopies were used to study the extent of specific interaction with various compositions and degrees of inter- and intramolecular hydrogen bonding, Moreover, the inter-association equilibrium constant and the related enthalpy of this phenolic/PAS blend were determined and used to predict the free energy and fraction of the hydrogen bonding according to the Painter-Coleman association model.
Miscibility and hydrogen bonding in blends of poly(vinyl acetate) with phenolic resin
(2002-04-01)
Huang, MW
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Kuo, SW
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Wu, HD
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Chang, FC
;
Fang, SY
The miscibility of phenolic resin and poly(vinyl acetate) (PVAc) blends was investigated by differential scanning calorimeter (DSC), Fourier transform infrared spectroscopy (FT-IR) and solid state C-13 nuclear magnetic resonance (NMR). This blend displays single glass transition temperature (T-g) over entire compositions indicating that this blend system is miscible in the amorphous phase due to the formation of hydrogen bonding between hydroxyl groups of phenolic resin and carbonyl groups of PVAc. Quantitative measurements on fraction of hydrogen-bonded carbonyl group using both C-13 solid-state NMR and FT-IR analyses result in good agreement between these two spectroscopic techniques. According to the proton spin-lattice relaxation time in the rotating frame (T-lp(H)), the phenolic/PVAc blend is intimately mixed on a scale less than 2-3 nm. Furthermore, the inter-association equilibrium constant and its related enthalpy of phenolic/PVAc blends were determined as a function of temperatures by infrared spectra based on the Painter-Coleman association model. (C) 2002 Elsevier Science Ltd. All rights reserved.
Effects of the relationship between resistivity and additive chemistries in electrochemically deposited copper films
(2002-04-01)
Chen, CF
;
Lin, KC
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材料科學與工程學系
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Department of Materials Science and Engineering
The room-temperature electrical resistance of copper films on silicon wafers deposited from acid-copper sulfuric solutions is a function of grain size and impurity content. These properties were examined by a series of additive chemistries used in plating baths. The trapped impurities and the functional characteristics of additives were analyzed by X-ray photoelectron spectroscopy (XPS) and cyclic voltammetric stripping (CVS) measurements, The impurity scattering effect on the resistances depends on the charge factor for different dopants. On the other hand, the effect of grain-boundary scattering on the resistances will depend on the extent of activation overpotential of various additive chemistries. Evidence suggests that additive chemistries with a higher overpotential would create a higher resistivity due to larger grain-boundary scattering and greater impurity incorporation into copper films.
Applicability of perturbative QCD and NLO power corrections for the pion form factor
(2002-04-01)
Yeh, TW
;
物理研究所
;
Institute of Physics
As is well recognized, the asymptotic of the perturbative QCD prediction for the pion form factor is much smaller than the upper end of the data. We investigate this problem. We first evaluate the next-to-leading-order (NLO) power correction for the pion form factor. The corrected form factor contains nonperturbative parameters which are determined from a chi(2) fit to the data. Interpreting these parameters leads to the fact that the involved strong interaction coupling constant should be identified as an effective coupling constant under a nonperturbative QCD vacuum. If the scale associated with the effective coupling constant is identified as (2)Q(2), then Q(2), the momentum transfer square for the pion form factor to be measured, can have a value about 1 GeV2, and , the averaged momentum fraction variable, can locate around 0.5. This circumstance is consistent with the asymptotic model for the pion wave function.
Subcooled flow boiling heat transfer of R-134a and the associated bubble characteristics in a vertical plate heat exchanger
(2002-04-01)
Hsieh, YY
;
Chiang, LJ
;
Lin, TF
;
機械工程學系
;
Department of Mechanical Engineering
Subcooled Row boiling heat transfer characteristics of refrigerant R-134a in a vertical plate heat exchanger (PHE) are investigated experimentally in this study. Besides, the associated bubble characteristics are also inspected by visualizing the boiling flow in the vertical PHE. In the experiment two vertical counterflow channels are formed in the exchanger by three plates of commercial geometry with a corrugated sinusoidal shape of a chevron angle of 60degrees. Upflow boiling of subcooled refrigerant R-134a in one channel receives heat from the downflow of hot water in the other channel. The effects of the boiling heat flux, refrigerant mass flux, system pressure and inlet subcooling of R-134a on the subcooled boiling heat transfer are explored in detail. The results are presented in terms of the boiling curves and heat transfer coefficients. The measured data showed that the slopes of the boiling curves change significantly during the onset of nucleate boiling (ONB) especially at low mass flux and high saturation temperature. Besides, the boiling hysteresis is significant at a low refrigerant mass flux. The subcooled boiling heat transfer coefficient is affected noticeably by the mass flux of the refrigerant. However, increases in the inlet subcooling and saturation temperature only show slight improvement on the boiling heat transfer coefficient. The photos from the flow visualization reveal that at higher imposed heat flux the plate surface is covered with more bubbles and the bubble generation frequency is substantially higher, and the bubbles tend to coalesce to form big bubbles. But these big bubbles are prone to breaking up into small bubbles as they move over the corrugated plate, producing strong agitating flow motion and hence enhancing the boiling heat transfer. We also note that the bubbles nucleated from the plate are suppressed to a larger degree for higher inlet subcooling and mass flux. Finally, empirical correlations are proposed to correlate the present data for the heat transfer coefficient and the bubble departure diameter in terms of boiling, Froude, Reynolds and Jakob numbers. (C) 2002 Elsevier Science Ltd. All rights reserved.
The ANNIGMA-wrapper approach to fast feature selection for neural nets
(2002-04-01)
Hsu, CN
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Huang, HJ
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Schuschel, D
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資訊工程學系
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Department of Computer Science
This paper presents a novel feature selection approach for backprop neural networks (NNs). Previously, a feature selection technique known as the wrapper model was shown effective for decision trees induction. However, it is prohibitively expensive when applied to real-world neural net training characterized by large volumes of data and many feature choices. Our approach incorporates a weight analysis-based heuristic called artificial neural net input gain measurement approximation (ANNIGMA) to direct the search in the wrapper model and allows effective feature selection feasible for neural net applications. Experimental results on standard datasets show that this approach can efficiently reduce the number of features while maintaining or even improving the accuracy. We also report two successful applications of our approach in the helicopter maintenance applications.
Global optimal fuzzy tracker design based on local concept approach
(2002-04-01)
Wu, SJ
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Lin, CT
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電控工程研究所
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Institute of Electrical and Control Engineering
In this paper, we propose a global optimal fuzzy tracking controller, implemented by fuzzily blending the individual local fuzzy tracking laws, for continuous and discrete-time fuzzy systems with the aim of solving, respectively, the continuous and discrete-time quadratic tracking problems with moving or model-following targets under finite or infinite horizon (time). The differential or recursive Riccati equations, and more, the differential or difference equations in tracing the variation of the target are derived. Moreover, in the case of time-invariant fuzzy tracking systems, we show that the optimal tracking controller can be obtained by just solving algebraic Riccati equations and algebraic matrix equations. Grounding on this, several fascinating characteristics of the resultant closed-loop continuous or discrete time-invariant fuzzy tracking systems can be elicited easily. The stability of both closed-loop fuzzy tracking systems can be ensured by the designed optimal fuzzy tracking controllers. The optimal closed-loop fuzzy tracking systems cannot only be guaranteed to be exponentially stable, but also be stabilized to any desired degree. Moreover, the resulting closed-loop fuzzy tracking systems possess infinite gain margin; that is, their stability is guaranteed no matter how large the feedback gain becomes. Two examples are given to illustrate the performance of the proposed optimal fuzzy tracker design schemes and to demonstrate the proved stability properties.
Possible evidence for the existence of the Fehrenbacher-Rice band: O K-edge XANES study on Pr1-xCaxBa2Cu3O7
(2002-04-01)
Hong, IP
;
Lin, JY
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Chen, JM
;
Chatterjee, S
;
Liu, SJ
X-ray absorption near edge structure (XANES), resistivity, and thermoelectric power have been measured on Pr1-xCaxBa2Cu3O7. These data reveal an intriguing electronic structure in Pr-doped cuprates. The absorption peak in XANES associated with the Fehrenbacher-Rice (FR) band has been identified. The Ca-doped holes in Pr1-xCaxBa2Cu3O7 go to both the Zhang-Rice (ZR) and FR bands. Comparative studies on the related samples suggest that the FR band is partially filled and highly localized. Implications of these results on other recent experiments, such as the observation of superconductivity in PrBa2Cu3O7 single crystals, are discussed.
Improvement on Peyravian-Zunic's password authentication schemes
(2002-04-01)
Hwang, JJ
;
Yeh, TC
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資訊管理與財務金融系註：原資管所+財金所
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Department of Information Management and Finance
Peyravian and Zunic (2000) presented two schemes for protecting password transmission and password change respectively. Like the traditional authentication scheme using passwords, the two new schemes are also vulnerable to attacks like guessing attacks, server spooling, and server data eavesdropping, This paper will give demonstrations on what have caused to these drawbacks, and more of that, two improved schemes are also proposed which are free from worries of those possible attacks.