Browsing by Issue Date, starting with "2013-09-30"

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Memory device application of wide-channel in-plane gate transistors with type-II GaAsSb-capped InAs quantum dots
(2013-09-30)
Liao, Yu-An
;
Chao, Yi-Kai
;
Chang, Shu-Wei
;
Chang, Wen-Hao
;
Chyi, Jen-Inn
We demonstrate room-temperature electron charging/discharging phenomena of InAs quantum dots using wide-channel in-plane gate transistors. The device based on type-II GaAsSb-capped InAs quantum dots exhibits both the longer charging and discharging times than those of the type-I counterpart with GaAs capping layers. The slow charge relaxation of GaAsSb-capped InAs quantum dots and simple architecture of in-plane gate transistors reveal the potential of this device architecture for practical memory applications. (C) 2013 AIP Publishing LLC.
High-performance resistive switching characteristics of programmable metallization cell with oxidized Cu-Ti electrodes
(2013-09-30)
Huang, Yu-Chih
;
Chou, Chia-Hsin
;
Liao, Chan-Yu
;
Tsai, Wan-Lin
;
Cheng, Huang-Chung
Programmable metallization cell (PMC) memory devices with oxidized Cu-Ti alloy films as the bottom electrodes have been shown to exhibit a superior on/off state current ratio (memory window) of as high as 10(3) and endurance of 3000 cycles as compared to conventional pure copper and unoxidized Cu-Ti alloy electrodes. It was conjectured that the Cu-Ti alloy electrodes could obtain the appropriate amount of copper atoms to format and rupture the conductive filaments in the resistive switching layer. Furthermore, the oxidized Cu-Ti alloys could control the Cu cations from the Cu and Cu2O to the appropriate amountto achieve the most favorable PMC characteristics. (C) 2013 AIP Publishing LLC.
Demonstrating 1 nm-oxide-equivalent-thickness HfO2/InSb structure with unpinning Fermi level and low gate leakage current density
(2013-09-30)
Hai-Dang Trinh
;
Lin, Yueh-Chin
;
Minh-Thuy Nguyen
;
Hong-Quan Nguyen
;
Quoc-Van Duong
In this work, the band alignment, interface, and electrical characteristics of HfO2/InSb metaloxide-semiconductor structure have been investigated. By using x-ray photoelectron spectroscopy analysis, the conduction band offset of 1.78 +/- 0.1 eV and valence band offset of 3.35 +/- 0.1 eV have been extracted. The transmission electron microscopy analysis has shown that HfO2 layer would be a good diffusion barrier for InSb. As a result, 1 nm equivalent-oxide-thickness in the 4 nm HfO2/InSb structure has been demonstrated with unpinning Fermi level and low leakage current of 10(-4) A/cm(-2). The D-it value of smaller than 10(12) eV(-1) cm(-2) has been obtained using conduction method. (C) 2013 AIP Publishing LLC.
Monitoring Debris Flows Using Spatial Filtering and Entropy Determination Approaches
(2013-10-01)
Kao, Hung-Ming
;
Ren, Hsuan
;
Lee, Chao-Shing
;
Chen, Yen-Liang
;
Lin, Yen-Shuo
We developed an automatic debris flow warning system in this study. The system uses a fixed video camera mounted over mountainous streams with a high risk for debris flows. The focus of this study is to develop an automatic algorithm for detecting debris flows with a low computational effort which can facilitate real-time implementation. The algorithm is based on a moving object detection technique to detect debris flow by comparing among video frames. Background subtraction is the kernel of the algorithm to reduce the computational effort, but non-rigid properties and color similarity of the object and the background color introduces some difficulties. Therefore, we used several spatial filtering approaches to increase the performance of the background subtraction. To increase the accuracy entropy is used with histogram analysis to identify whether a debris flow occurred. The modified background subtraction approach using spatial filtering and entropy determination is adopted to overcome the error in moving detection caused by non-rigid and similarities in color properties. The results of this study show that the approach described here can improve performance and also reduce the computational effort.
Particle image velocimetry measurement of jet impingement in a cylindrical chamber with a heated rotating disk
(2013-10-01)
Liu, Yao-Hsien
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Tseng, Li-Wei
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Huang, Chih-Yung
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Lin, Kung-Liang
;
Chen, Chien-Chih
We studied the flow field of a jet impingement on a rotating heated disk to simulate the flow field surrounding the rotating disk of a chemical vapor deposition (CVD) reactor, which is widely used for large-scale production of thin-films and semiconductor materials. The flow field influences the growth rate and deposition uniformity, and is subject to the combined effects of buoyancy, centrifugal, and flow inertia forces that occur during the deposition process. The study investigated various flow-cell sizes and locations, such as the inlet flow-rate (1-10 slpm), jet-to-disk temperature difference (40-80 degrees C), and disk rotational speeds (0-500 rpm). Particle image velocimetry (PIV) was used to measure the flow-velocity field and flow-streamlines in the test chamber. The time-averaged axial and radial velocity profiles near the disk were used to determine the variations in flow velocity resulting from rotation and heating. Upward buoyancy forces, caused by the heated disk, produce flow cells and break the flow uniformity above the disk. When the rotational Reynolds number increases, the rotational effect eventually dominates the flow field that increases the flow velocity and generates flow cells near the chamber wall. Flow regime maps of these flow patterns were constructed, based on the Grashof number and rotational Reynolds number. (c) 2013 Elsevier Ltd. All rights reserved.
Reliability-based stochastic transit assignment with capacity constraints: Formulation and solution method
(2013-10-01)
Szeto, W. Y.
;
Jiang, Yu
;
Wong, K. I.
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Solayappan, Muthu
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運輸與物流管理系註：原交通所+運管所
This paper proposes a Linear Complementarity Problem (LCP) formulation for the reliability-based stochastic transit assignment problem with capacity constraints and non-additive link costs, where in-vehicle travel times and waiting times are uncertain. The capacity constraints are developed via the notions of effective capacity and chance constraints. An equivalent route-based linear program (LP) for the proposed problem is formulated to determine the patronage of each line section, critical links, critical service frequencies, unmet demand and the network capacity, which considers the risk-aversive behavior of travelers. A solution method is developed, utilizing the IC-shortest path algorithm, the column generation technique, and the revised simplex method, to solve the proposed LP with guaranteed finite convergence. Numerical experiments are also set up to illustrate the properties of the problem and the application of the proposed model for reliability analysis. (C) 2011 Elsevier Ltd. All rights reserved.
Canonical Ensemble Statistics of Weakly Interacting Composite Boson Condensation: Thermodynamic Properties
(2013-10-01)
Lee, Ming-Tsung
;
光電工程學系
;
Department of Photonics
We present a canonical ensemble approach for weakly interacting composite boson systems, which is confined with a finite number of particles. Composite bosons, made of fermion pairs, correlate to each other through the Coulomb interaction associated with the fermion exchange, and are treated perturbatively. We study Bose-Einstein condensation of composite bosons according to the specific heat capacity, the composite-boson distribution function, and the condensate fraction up to the first-order perturbations. As an example, we investigate two-dimensional confined excitons. The study shows that the fermion exchange tends to assist the exciton condensation by raising the temperature. This stabilization of the exciton condensation owing to the fermion exchange is characterized by a small trough in the specific heat capacity profile. As the temperature becomes higher than the transition temperature, the effective Coulomb interaction reduces the thermal fluctuation of excitons, leading to a negative correction to the specific heat capacity in the normal phase. Weakly interacting excitons stay in a more stable thermodynamic state in comparison with ideal exciton gases.
Factors Related to Fungiform Papillae Density: The Beaver Dam Offspring Study
(2013-10-01)
Fischer, Mary E.
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Cruickshanks, Karen J.
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Schubert, Carla R.
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Pinto, Alex
;
Klein, Ronald
The distribution of fungiform papillae density and associated factors were examined in the Beaver Dam Offspring Study. Data were from 2371 participants (mean age 48.8 years, range 2184 years) with 1108 males and 1263 females. Fungiform papillae were highlighted with blue food coloring and the number of fungiform papillae within a standard 6-mm circle was counted. Whole mouth suprathreshold taste intensity was measured. The mean fungiform papillae density was 103.5 papillae/cm(2) (range 0212.2 papillae/cm(2)). For each 5-year increase in age, the mean fungiform papillae density was 2.8 papillae/cm(2) lower and the mean density for males was 10.2 papillae/cm(2) lower than for females. Smokers had significantly lower mean densities (former smokers: 5.1 papillae/cm(2); current smokers: 9.3 papillae/cm(2)) than nonsmokers, and heavy alcohol drinkers had a mean density that was 4.7 papillae/cm(2) lower than nonheavy drinkers. Solvent exposure was related to a significantly higher density (6.8 papillae/cm(2)). The heritability estimate for fungiform papillae density was 40.2%. Propylthiouracil taster status, TAS2R38 haplotype, and perceived taste intensity were not related to density. In summary, wide variability in fungiform papillae density was observed and a number of related factors were found including the modifiable factors of smoking and alcohol consumption.
High-Performance Programmable Metallization Cell Memory With the Pyramid-Structured Electrode
(2013-10-01)
Huang, Yu-Chih
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Tsai, Wan-Lin
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Chou, Chia-Hsin
;
Wan, Chung-Yun
;
Hsiao, Ching
The pyramid structure fabricated with the potassium hydroxide (KOH) anisotropically etched (100) silicon substrate has been deposited with a copper film as the bottom electrode of the programmable metallization cell (PMC) memory to significantly improve the resistive switching characteristic. As compared with the conventional flat copper electrode, this pyramid-structured electrode exhibited the set/reset voltage as low as 1/0.6 V and superior endurance of 2400 cycles at the set/reset voltages of -5/+3 V for the voltages pulsewidth of 1 mu s. The high performance of this PMC could be attributed to high local electrical fields at the tips of the pyramid structure, resulting in the formation of the narrower conductive filaments that facilitate the lower operation voltage and better endurance.
節能化色溫調校方法
(2013-10-01)
歐陽盟
;
黃庭緯
;
陳子賢
;
邱俊誠
本發明係揭露一種節能化色溫調校方法,首先擷取至少三原色之原色座標及其最大亮度,以據此建立原色之色域,此色域具有至少三重心線。接著,判斷重心線與一等色溫線段或一目標色溫容差範圍是否相交,若有,則取得重心線與等色溫線段或目標色溫容差範圍相交之一交點座標,若無,則在等色溫線段或目標色溫容差範圍上,取得與重心線最接近之一端點座標。最後,依據交點座標與端點座標其中之一,調整上述原色之色溫,達到最節能之目的。
Modeling diffusion of multi-generational LCD TVs while considering generation-specific price effects and consumer behaviors
(2013-10-01)
Tsai, Bi-Huei
;
管理科學系
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Department of Management Science
An effective diffusion model characterized by the technology-induced function diversification and cost reductions can be developed to reflect whether competition exists among multiple generations of technology and to interpret how price reductions stimulate consumption. New technology can enhance the production skill levels of LCD TV manufacturing, enabling successive generation of LCD TV to become larger-sized than the previous generation, reducing the overall cost in manufacturing process and resulting in the price reduction of LCD TVs. However, previous diffusive predictions of LCD TVs using conventional multi-generational models ignore the price effect on market potentials and generational substitutions, so a novel generation-specific multi-generational model for the first time incorporating heterogeneous price elasticity and consumer behaviors across various LCD TV sizes is constructed in this work. This study applies nonlinear least square method to simulate the parameters of our modified model and further compares the accuracy between our modified model and the existing models. Analytical results indicate that price reduction strongly correlates with LCD TV sales, implying that price reductions increase the market potential of each LCD TV generation. Our modified model performs superior to the conventional multi-generational model in terms of predicting future shipment orbits of 26-, 42-, and 46-in. LCD TVs. (C) 2013 Elsevier Ltd. All rights reserved.
使用邏輯努力緩衝時脈偏差之方法
(2013-10-01)
謝忠穎
;
張銘宏
;
黃威
一種使用邏輯努力(logical effort)緩衝時脈偏差之方法，供應用於處在強反轉區域(strong-inversion region)、中反轉區域(moderate-inversion region)、或弱反轉區域(weak-inversion region)之時脈樹，包含以下步驟：於該時脈樹中設置溫度感測模組及寬度可調變之緩衝器(Tunable-Width Buffer)，並依據邏輯努力函式分別建置出供該緩衝器適用於強反轉區域、中反轉區域、及弱反轉區域中的寬度與溫度之對照表；依據該時脈樹所處之反轉區域從建置出的寬度與溫度之對照表中選擇對應之對照表，並令該溫度感測模組進行溫度感測，且由所選擇的寬度與溫度之對照表中依據所感測之溫度查詢對應的寬度值；以及依據查詢出的寬度值令該緩衝器進行寬度調變，藉此緩衝時脈偏差。
Reactant and Waste Minimization in Multitarget Sample Preparation on Digital Microfluidic Biochips
(2013-10-01)
Huang, Juinn-Dar
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Liu, Chia-Hung
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Lin, Huei-Shan
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
Sample preparation is one of essential processes in biochemical reactions. Raw reactants are diluted in this process to achieve given target concentrations. A bioassay may require several different target concentrations of a reactant. Both the dilution operation count and the reactant usage can be minimized if multiple target concentrations are considered simultaneously during sample preparation. Hence, in this paper, we propose a multitarget sample preparation algorithm that extensively exploits the ideas of waste recycling and intermediate droplet sharing to reduce both reactant usage and waste amount for digital microfluidic biochips. Experimental results show that our waste recycling algorithm can reduce the waste and operation count by 48% and 37%, respectively, as compared to an existing state-of-the-art multitarget sample preparation method if the number of target concentrations is ten. The reduction can be up to 97% and 73% when the number of target concentrations goes even higher.
The exceptional photo-catalytic activity of ZnO/RGO composite via metal and oxygen vacancies
(2013-10-01)
Chen, Ting-Ting
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Chang, I-Chun
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Yang, Min-Han
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Chiu, Hsin-Tien
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Lee, Chi-Young
ZnO/reduced graphene oxide (RGO) nanocomposite with many zinc and oxygen vacancies, synthesized in a simple solvothermal reaction exhibits significant photocatalytic activity. Photoluminescence and electron paramagnetic resonance measurements indicate that the zinc vacancies and oxygen vacancies were generated on the ZnO surface, and were crucial to that photocatalytic behavior. The photodegradation of methylene orange was significantly reduced by the addition of h(+) and (OH)-O-center dot scavengers. Both zinc and oxygen vacancies cause effective charge separation in the photodegradation of methylene orange, which markedly inhibits the recombination of charges. The advanced photocatalytic behavior of the ZnO/RGO composite is discussed in detail herein. (c) 2013 Elsevier B.V. All rights reserved.
Comparative Leakage Analysis of GeOI FinFET and Ge Bulk FinFET
(2013-10-01)
Hu, Vita Pi-Ho
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Fan, Ming-Long
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Su, Pin
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Chuang, Ching-Te
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電子工程學系及電子研究所
We present a comparative leakage analysis of germanium-on-insulator (GeOI) FinFET and germanium on bulk substrate FinFET (Ge bulk FinFET) at device and circuit levels. Band-to-band tunneling (BTBT) leakage-induced bipolar effect is found to result in an amplified BTBT leakage for GeOI FinFET. Device and circuit designs to mitigate the amplified BTBT leakage of GeOI FinFETs are suggested. The effectiveness of various high threshold voltage technology options including increasing channel doping, increasing gate length and drain-side underlap for leakage reduction is analyzed.
In-situ Formation and Assembly of Gold Nanoparticles by Gum Arabic as Efficient Photothermal Agent for Killing Cancer Cells
(2013-10-01)
Liu, Ching-Ping
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Lin, Fong-Sian
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Chien, Chih-Te
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Tseng, Sheng-Yang
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Luo, Chih-Wei
250-GHz Passive Harmonic Mode-Locked Er-Doped Fiber Laser by Dissipative Four-Wave Mixing With Silicon-Based Micro-Ring
(2013-10-01)
Jyu, Siao-Shan
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Yang, Ling-Gang
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Wong, Chi-Yan
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Yeh, Chien-Hung
;
Chow, Chi-Wai
We propose and demonstrate a 250-GHz high-repetition-rate mode-locked Er-doped fiber laser, which utilizes a silicon micro-ring resonator (SMRR). The SMRR acts as an optical comb filter to help achieve passive mode-locking through the dissipative four-wave-mixing effect induced by a piece of high nonlinear fiber. A short section of polarization-maintaining fiber is inserted in the cavity to induce birefringence filtering to significantly enhance the stability of the proposed laser through the combined effects of optical filtering and nonlinear spectral broadening. The laser can operate about 2 and 6 nm in the case of 1.48-ps and 875-fs output pulsewidth, with 3-dB bandwidth, respectively. The laser can remain mode locked, during our measurement time, without any cavity length or temperature feedback control.
Optimal Linear Channel Prediction for LTE-A Uplink Under Channel Estimation Errors
(2013-10-01)
Wu, Jwo-Yuh
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Lee, Wen-Ming
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電機資訊學士班
;
Undergraduate Honors Program of Electrical Engineering and Computer Science
This paper proposes an optimal design of the linear channel prediction scheme for LTE-A uplink transmission, taking into account the effect of channel estimation errors. The optimization criterion is to minimize mean square prediction errors, averaged over the distributions of true channel coefficients and estimation errors. We derive a closed-form solution of the optimal channel predictor and provide exact analysis for the achievable mean square error (MSE). The performance gain, in terms of the amount of reduction in MSE, as compared with the conventional channel predictor, is also analytically characterized. Simulation results are used to validate our MSE analyses and to confirm the performance advantage of the proposed solution.
The "cascade effect" of nano/micro hierarchical structure: A new concept for designing the high photoactivity materials - An example for TiO2
(2013-10-01)
Chen, Po-Chin
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Tsai, Min-Chiao
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Yang, Min-Han
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Chen, Ting-Ting
;
Chen, Huang-Chin
The chrysanthemum-like TiO2 (CT800) was synthesized. It exhibited excellent photoactivity, which greatly exceeded that of conventional P25. To discover the key factors that governed the photocatalytic properties, the specific reduction of Ag+ ions was carried out and EPR spectra of CT800 were obtained. Both an HADDF image and EDX mapping indicated that the Ag+ ions tended to be reduced close to the center of the micro matrix of CT800. Moreover, the EPR spectra strongly suggest that the excited electrons tended to migrate toward the center of the micro matrix, resulting from a multiple junction, cascade effect, which efficiently reduces the recombination of excited electrons and holes and greatly increases the photoactivity. Additionally, the special morphology of CT800 was responsible for the hot spots at the surface of nano sheets and then contributing to its outstanding photocatalytic activity. Furthermore, the unidirectional electron transfer, because of the cascade effect, by materials of different sizes provides a new avenue for the design of electronic and photoelectrochemical devices. (c) 2013 Elsevier B.V. All rights reserved.
Effect of nickel concentration on source/drain series resistance and channel resistance of Ni-metal-induced crystallization thin-film transistors
(2013-10-01)
Lai, Ming-Hui
;
Wu, YewChung Sermon
;
Huang, Jung-Jie
;
材料科學與工程學系
;
Department of Materials Science and Engineering
The Ni-metal-induced crystallization (MIC) of amorphous Si (a-Si) has been employed to fabricate low-temperature polycrystalline silicon (poly-Si) thin-film transistors (TFTs). Most studies have focused only on reducing Ni contamination because Ni residues cause high leakage current in MIC-TFTs. Also of concern is the source/drain (S/D) series resistance, which degrades the device performance (driving ability) that might vary with the Ni concentration in MIC-TFTs. Improving the driving ability of MIC-TFTs requires a detailed understanding of how Ni residues affect S/D series resistance. This study investigates how Ni concentration affects S/D series resistance by using the transmission line method. The results of this study provide further insight into how Ni concentration and resistance are related. The results show that the S/D series resistance and channel resistance decreased with a reduction in Ni concentration in MIC poly-Si because of better crystalline quality and lower degradation of the donor concentration. This phenomenon was caused by the Ni concentration forming less NiSi2 nucleation sites to generate a large grain size; Ni atoms serve as acceptor-like dopants in silicon, which counteract with the effects of n-type doping, subsequently reducing the donor concentration in the S/D region. (C) 2013 Elsevier B. V. All rights reserved.