Browsing by Issue Date, starting with "2005-05-21"

Now showing 1 - 20 of 66665

可調整位元流大小的影像編解碼裝置
(2005-05-21)
黃項群
;
王俊能
;
蔣迪豪
;
杭學鳴
一種可調整位元流大小的影像編碼裝置，包含一基層編碼器和一加強層編碼器。經由比較原始影像與基層編碼器和加強層編碼器中具運動補償之預測影像產生運動補償差異影像。以滲漏預測和部份預測為基礎，在加強層建造高品質參考影像以改進時間上的預測。在高品質參考影像的建造中，參數β控制使用的加強層差異係數的位元平面數，而另一個參數α控制預測滲漏的量。空間的可調整大小模組允許基層和加強層處理的圖形具有相同或不同的空間解析度。
製造上瑕疵偵測方法及其系統
(2005-05-21)
曾憲雄
;
陳威州
;
王慶堯
本發明提供一種新穎的製造上瑕疵偵測方法，該方法係用以在一個使用多數機器之製程中找尋造成產品瑕疵之主因機器集合(machine set)。本發明之製造上瑕疵偵測方法包括：取得在一製程中與產品製造有關之製造資料；分析該製造資料而產生一機器集合(machine set)之候選名單；其中該機器集合包括與該產品之瑕疵有關之機器；及在該機器集合名單中找尋，產生一瑕疵主因機器集合；其中該瑕疵主因機器集合包括與該產品瑕疵高度相關之機器。
用於防盜之監視系統
(2005-05-21)
吳炳飛
;
陳昭榮
;
彭信元
本發明係有關於一種用於防盜之監視系統，係組設有至少一攝影機以對監視物進行攝影，並將取得之影像傳送至遠端之可攜式裝置，並顯示攝影機所取得之影像，讓使用者能即時對監視物進行監視。
Mechanism for singular behavior in vibrational spectra of topologically disordered systems: Short-range attractions
(2005-05-22)
Wu, TM
;
Chang, SL
;
Tsai, KH
;
物理研究所
;
Institute of Physics
At low-enough fluid densities, we have found some naive singular behavior, like the van Hove singularities in the phonon spectra of lattices, appearing in the instantaneous normal mode spectra of the Lennard-Jones (LJ) 2n-n fluids, which serve as a prototype of topologically disordered systems. The singular behavior cannot be predicted by the mean-field theory, but interpreted by the perturbed binary modes of some special pairs, called the mutual nearest neighbor pairs, at separations corresponding to the extreme binary frequencies, which are solely determined by the attractive part of the LJ 2n-n pair potential. By reducing the range of attraction in the pair potential under the conditions of the same particle diameter and well depth, the tendency for the appearance of the singular behavior shifts to higher fluid densities. From this study, we conclude that pair potential with a short-range attraction can be a mechanism to produce a counterpart of the van Hove singularity in the vibrational spectra of disordered systems without a reference lattice. 2005 American Institute of Physics.
A study on the hardness variation of alpha- and beta-pure titanium with different grain sizes
(2005-05-25)
Kao, YL
;
Tu, GC
;
Huang, CA
;
Liu, TT
;
材料科學與工程學系
In this study, the hardness and the microstructure of alpha and beta-pure Ti treated with different grain sizes were investigated. The alpha-Ti specimens were obtained by heating pure Ti at 750 degrees C for various periods and then quenched in water, while the beta-Ti specimens by heating at 1000 degrees C for various periods and then quenched in water. Experimental results show that the hardness of a-Ti decreased with increasing the grain size; whereas, the hardness of beta-Ti tends to increase with increasing grain size. From the microstructures examined with transmission electron microscope, it can be realized that the strengthening mechanisms of alpha- and beta-Ti are quite different. Grain boundary could be the main strengthening microstructure of alpha-Ti and the smaller grain size the higher hardness. The major strengthening microstructure of beta-Ti was martensitic twin with a very high dislocation density. The amount of martensitic twin increased with increasing the grain size of beta-Ti and, therefore, the larger grain size the higher hardness. (c) 2005 Elsevier B.V. All rights reserved.
Fast direct solver for the biharmonic equation on a disk and its application to incompressible flows
(2005-05-25)
Lai, MC
;
Liu, HC
;
應用數學系
;
Department of Applied Mathematics
We develop a simple and efficient FFT-based fast direct solver for the biharmonic equation on a disk. The biharmonic equation is split into a coupled system of harmonic problems. We first use the truncated Fourier series expansion to derive a set of coupled singular ODEs, then we solve those singular equations by second-order finite difference discretizations. Using a radial grid with shifting a half mesh away from the origin, we can handle the coordinate singularity easily without pole conditions. The Sherman-Morrison formula is then applied to solve the resultant linear system in a cost-efficient way. The computational complexity of the method consists of O(MN log(2) N) arithmetic operations for M x N grid points. The numerical accuracy check and some applications to the incompressible Navier-Stokes flows inside a disk are conducted. (c) 2004 Elsevier Inc. All rights reserved.
Model identification of ARIMA family using genetic algorithms
(2005-05-25)
Ong, CS
;
Huang, JJ
;
Tzeng, GH
;
運輸與物流管理系註：原交通所+運管所
;
科技管理研究所
ARIMA is a popular method to analyze stationary univariate time series data. There are usually three main stages to build an ARIMA model, including model identification, model estimation and model checking, of which model identification is the most crucial stage in building ARIMA models. However there is no method suitable for both ARIMA and SARIMA that can overcome the problem of local optima. In this paper, we provide a genetic algorithms (GA) based model identification to overcome the problem of local optima, which is suitable for any ARIMA model. Three examples of times series data sets are used for testing the effectiveness of GA, together with a real case of DRAM price forecasting to illustrate an application in the semiconductor industry. The results show that the GA-based model identification method can present better solutions, and is suitable for any ARIMA models. (c) 2004 Elsevier Inc. All rights reserved.
Microstrip directional coupler with nearly ideal TEM coupler performance
(2005-05-26)
Wang, SM
;
Hsieh, MY
;
Chiang, CH
;
Chang, CY
;
電信工程研究所
A meandered parallel coupled-line structure is proposed to achieve high directivity within a wide bandwidth. By properly increasing the meandered parallel coupled-line sections, the high-directivity band-width becomes much wider. An example coupler is fabricated to verify the theory. More than 50 dB of isolation is achieved over a bandwidth of zero to twice centre frequency.
Control of enhanced THz transmission through metallic hole arrays using nematic liquid crystal
(2005-05-30)
Pan, CL
;
Hsieh, CF
;
Pan, RP
;
Tanaka, M
;
Miyamaru, F
We demonstrate frequency tuning of enhanced THz radiation transmitted through a two- dimensional metallic hole array ( 2D- MHA) by controlling the index of refraction of the medium filling the holes and adjacent to the 2D- MHA on one side. The medium is a nematic liquid crystal ( NLC) and its index of refraction is varied using magnetically controlled birefringence of the NLC. With the NLC, the peak transmission frequency of the 2D- MHA shift to the red by 0.112 THz and can be tuned from 0.193 to 0.188 THz. The peak transmittance is as high as 70% or an enhancement of 2.42 times, considering the porosity of the 2D- MHA. As a tunable THz filter, this device exhibits a continuous tuning range of 4.7 GHz, a low insertion loss of 2.35 to 1.55 dB and a quality factor of similar to 4- 5. (C) 2005 Optical Society of America.
Characterization of CF4-plasma fluorinated HfO2 gate dielectrics with TaN metal gate
(2005-05-30)
Lai, CS
;
Wu, WC
;
Wang, JC
;
Chao, T
;
物理研究所
In this paper, fluorine incorporation into the HfO2 gate dielectrics by post CF4 plasma treatment was proposed to improve the electrical characterization. TaN-HfO2-p-Si capacitors were demonstrated in this work. The characteristics of fluorinated HfO2 gate dielectrics were improved, including the capacitance-voltage hysteresis and current-voltage behaviors. This may be attributed to the fluorine incorporated into the HfO2 gate dielectrics as revealed by secondary ion mass spectroscopy. Moreover, the formation of Hf-F bonding was observed through electron spectroscopy for chemical analysis spectra. (c) 2005 American Institute of Physics.
An unusual, completely miscible, ternary hydrogen-bonded polymer blend of phenoxy, phenolic, and PCL
(2005-05-31)
Kuo, SW
;
Chan, SC
;
Wu, HD
;
Chang, FC
;
應用化學系
We have investigated the miscibility and hydrogen-bonding behavior of ternary blends of phenoxy, phenolic, and poly(e-caprolactone) (PCL) by using differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy. On the basis of DSC analyses, we observed a rare totally miscible ternary hydrogen-bonded polymer blend in the amorphous phase: all compositions of this ternary blend display a single glass transition temperature. In addition, these single glass transition temperatures can be predicted well by extending the Kwei equation from the binary polymer blend to this ternary polymer blend. The infrared spectra indicate that the intermolecular hydrogen bonding of each pair of binary components still exists in the ternary polymer blend. We used the ternary totally miscible blend to determine the interassociation equilibrium constant between the hydroxyl groups of phenolic and the hydroxyl groups of phenoxy indirectly from the fraction of hydrogen-bonded carbonyl groups of PCL. Quantitative analyses suggest that interassociation between the hydroxyl groups of phenolic and the hydroxyl groups of phenoxy is more favorable than the hydroxyl-carbonyl interassociations of either phenolic/PCL or phenoxy/PCL and the hydroxyl-hydroxyl self-association of the pure phenolic and phenoxy homopolymers at room temperature.
Perceived fairness of pricing on the Internet
(2005-06-01)
Huang, JH
;
Chang, CT
;
Chen, CYH
;
管理科學系
;
經營管理研究所
The perceived fairness of price changes has been a subject of much inquiry in economic and marketing literature. This paper examines consumers' perceptions of the fairness of pricing on the Internet. Fair prices on the Internet, pricing mechanisms, methods of price discrimination and yield management are investigated from a consumer's perspective. Results obtained from 276 questionnaires collected in Taiwan indicate that the Internet prices that equal those in the traditional channels are perceived to be unfair. Respondents considered various pricing mechanisms on the Internet to be fair while many practices of price discrimination and yield management were perceived to be unfair. © 2004 Elsevier B.V. All rights reserved.
Reliability of strained SiGe channel p-channel metal-oxide-semiconductor field-effect transistors with ultra-thin (EOT=3.1nm) N2O-annealed SiN gate dielectric
(2005-06-01)
Chen, CW
;
Chien, CH
;
Chen, YC
;
Hsu, SL
;
Chang, CY
The p-channel metal-oxide-semi conductor field-effect transistor (pMOSFET) with 50-nm-thick Si0.85Ge0.15 channel and in ultra-thin (EOT = 3.1 nm) N2O-annealed SiN gate dielectric has been shown to have well-performing on/off and output characteristics. Several methodologies for the device reliability characterization, such as stress-induced-leakage-current (SILC), drain-avalanche-hot-carrier (DAHC) injection, channel hot-carrier (CHC) injection and negative-bias-temperature-instability (NBTI), have been used and the results were compared. In terms of the long-term degradation, the excellent quality of the N2O-annealed SiN gate dielectric can be firmly obtained because only negligible degradations have been found after stressing no matter which technique was employed. Even so, the experimental results have been compared and we found that the HC degradation is worse than the NBTI degradation and the channel-hot-carrier (CHC) stressing is the worst case for all kinds of reliability testing. Meanwhile, we have also verified that the interface state generation is the dominant mechanism responsible for the HC-induced degradation while the electron trapping dominates the device degradation for the NBTI stressing.
Implementation of wireless network environments supporting inter access point protocol and dual packet filtering
(2005-06-01)
Hwang, LY
;
Chiang, ML
;
Chang, RC
;
資訊工程學系
;
Department of Computer Science
With advances in wireless technologies, future internetworks will include large numbers of mobile hosts roaming across wireless cells. The goal of this paper is to provide a wireless network communication environment, in which mobile hosts can roam among various access points (wireless cells) and across different subnets. For this purpose, we develop methods to implement and integrate the communication mechanisms of Mobile IP and Inter Access Point Protocol (IAPP). For efficient transmission, we also devise a dual packet filtering technique to filter out unnecessary packet transmission, thereby reducing traffic on wireless networks. Such filtering is especially important because of the limited bandwidth of wireless links. Our work can serve as the reference once IAPP has been approved as standard. (c) 2004 Elsevier Inc. All rights reserved.
Improving high-temperature performance in continuous-wave mode InGaAsN/GaAsN ridge waveguide lasers
(2005-06-01)
Chang, YA
;
Kuo, HC
;
Lu, CY
;
Kuo, YK
;
Wang, SC
Continuous-wave (CW) mode operation InGaAsN/GaAsN double-quantum-well lasers with a laser wavelength of 1.295 mu m are demonstrated by metal-organic chemical vapour deposition (MOCVD). With the use of a high-bandgap GaAs0.9P0.1 into the active region before the growth of p-type layers, a room temperature (RT) threshold current of 99 mA and the characteristic temperature (TO) values of 155 K in a temperature range of 25-95 degrees C and 179 K in a temperature range of 25-85 degrees C are obtained from a 4 x 1000 mu m(2) ridge waveguide uncoated laser diode. The To value of the conventional structure without the high-bandgap GaAs0.9P0.1 is 118 K in a temperature range of 25-95 degrees C. High-temperature performance is improved and the results of numerical analysis suggest that it may be attributed to the reduced electronic leakage current.
Spin-flip transport through an interacting quantum dot
(2005-06-01)
Lin, KC
;
Chuu, DS
;
電子物理學系
;
Department of Electrophysics
The spin-flip associated transport based on the Anderson model is studied. It is found that the electrons are scattered due to spin-flip effect via the normal, mixed and Kondo channels. The spin-flip scattering via Kondo channel enhances the Kondo resonance peak and causes a slight blue shift. The conductance is suppressed by the spin-flip scattering. This is attributed to the reason that electrons with energy near Fermi level are scattered by Kondo channel. (c) 2005 Elsevier Ltd. All rights reserved.
一種超薄型平面喇叭之結構及其最佳化設計方法
(2005-06-01)
白明憲
;
呂彥志
本發明係為一種超薄型平面喇叭之結構及其最佳化設計方法，其結構包含一板材、一壓電材料一導電材以及懸邊。最佳化設計方法之模擬系統是以能量法與變分原理為基礎理論並利用有限元素法求解，其中程序同時考慮電能系統、機械系統以及聲場系統空氣之負載效應。再利田口實驗計畫法與基因演算法做結構之最佳化設計，以使得超薄型平面喇叭在較低之共振頻率下仍能維持與高共振頻率時之平均聲壓值相近，以達音質、音量最佳之目的。本創作之特點在於透過喇叭結構之最佳化程序可充分發揮音質喇叭之優點，不僅可以製作成任意平面形狀，大幅提高喇叭之聲功率，而且使用上非常省電有效率，並可改善喇叭在高共振頻率時，聲音太過尖銳之缺點。
A novel process-compatible fluorination technique with electrical characteristic improvements of poly-Si TFTs
(2005-06-01)
Wang, SD
;
Lo, WH
;
Chang, TY
;
Lei, TF
;
電子工程學系及電子研究所
A process-compatible fluorine passivation technique of poly-Si thin-film transistors (TFTs) was demonstrated by employing a novel CF4 plasma treatment. Introducing fluorine atoms into poly-Si films can effectively passivate the trap states near the SiO2/poly-Si interface. With fluorine incorporation, the electrical characteristics of poly-Si TFTs can be significantly improved including a steeper subthreshold slope, smaller threshold voltage, lower leakage current, higher field-effect mobility, and better On/Off current ratio. Furthermore, the CF4 plasma treatment also improves the reliability of poly-Si TFTs with respect to hot-carrier stress, which is due to the formation of strong Si-F bonds.
Intracavity PPLN crystals for ultra-low-voltage laser Q-switching and high-efficiency wavelength conversion
(2005-06-01)
Chen, YH
;
Huang, YC
;
Lin, YY
;
Chen, YE
;
電子物理學系
We report to the best of our knowledge the lowest switching voltage in an electro-optically Q-switched Nd: YVO4 laser by using a 13-mm long, 14-μ m-period PPLN crystal as a Pockels cell. A switching voltage as low as &SIM; 50V in the PPLN crystal was sufficient to hold off the lasing of the Q-switched laser at a pump power more than two times above its continuous-wave threshold. When the PPLN Q-switch was driven by a 100-V voltage at 6.5 kHz, we obtained 0.9-kW laser peak power from this 1-W diode-pumped Nd: YVO4 laser system with 13% output coupling. When the PPLN Pockels cell was cascaded with a 5-cm long, 30-μ m-period PPLN crystal, we produced &SIM; μ J/pulse energy at 1.59 μ m from optical parametric generation inside the actively Q-switched laser.
Guest editorial - Mobile computing and networking
(2005-06-01)
Wei, DSL
;
Naik, K
;
Lin, YB
;
Olariu, S
;
Wang, LC