Browsing by Issue Date, starting with "2011-07-01"

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Second-Order Extended H-infinity Filter for Nonlinear Discrete-Time Systems Using Quadratic Error Matrix Approximation
(2011-07-01)
Hu, Jwu-Sheng
;
Yang, Chia-Hsing
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this paper, the second-order extended (SOE) H-infinity filter for nonlinear discrete-time systems is derived based on an approximation to the quadratic error matrix. The solution is obtained by the game theory approach. It is shown that the result bears a strong resemblance to the SOE Kalman filter when the performance bound goes to infinity. An example of vehicle state tracking is simulated to compare the performances of the SOE Kalman filter, the first order extended and the SOE H-infinity filter. Noises with unknown bias are injected into both process dynamics and measurements. The results show that the SOE H-infinity filter has the smallest state tracking error.
The Growth of an Epitaxial ZnO Film on Si(111) with a Gd(2)O(3)(Ga(2)O(3)) Buffer Layer
(2011-07-01)
Lin, B. H.
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Liu, W. R.
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Yang, S.
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Kuo, C. C.
;
Hsu, C. -H.
High-quality (0001)-oriented ZnO epitaxial films have been grown by pulsed laser deposition on Si(111) buffered with a nanometer-thick Gd(2)O(3)(Ga(2)O(3)), GGO, layer. The structural characteristics of the ZnO epi-layers were studied by X-ray diffraction and transmission electron microscopy (TEM). The in-plane epitaxial relationship between the wurtzite ZnO, cubic GGO, and cubic Si follows {10 (1) over bar0}(ZNO)parallel to{4 (22) over bar}(Gd2O3)parallel to{(4) over bar 22}(Si) and the ZnO/GGO interface can be described by the domain matching epitaxy. TEM contrast analysis reveals that the major defect structures in the ZnO films are edge-type threading dislocations and intrinsic basal plane stacking faults. All the ZnO epi-films studied are under a tensile biaxial strain, but no cracks were found. Temperature-dependent photoluminescence results show the excellent optical properties of the obtained ZnO layers, and the origins of the spectral features are discussed.
A two-phase algorithm for product part change utilizing AHP and PSO
(2011-07-01)
Huang, P. C.
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Tong, L. I.
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Chang, W. W.
;
Yeh, W. C.
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工業工程與管理學系
This study presents a two-phase algorithm approach to deal with the issue of product part change, and the issue of supplier selection derived from the former. In the first step, Analytical Hierarchy Process (AHP) was used on expert interview records to select the module in a product that needs to be changed with top priority. In the second step, after changing the module, the supplier selection process, including building a mathematical programming model, was initiated to select the best suppliers using Particle Swarm Optimization (PSO) algorithm. We tried to use this method to maximize the value of product updating so as to extend the product life cycle, under the conditions of limited resource, and keeping the scope of change to a minimum. Finally, we selected a switchboard manufacturer as a case study to test the proposed algorithm. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
First principles study of the electron density distribution in a pair of bare metallic electrodes
(2011-07-01)
Ma, Chun-Lan
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Chen, Yu-Chang
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Nghiem, Diu
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Tseng, Allen
;
Huang, Pao-Chieh
Self-consistent calculations of electron density distribution from first principles for a series of semi-infinite metals show that the electron density almost drops to zero at 8.5 a.u. away from a metal surface. The electron densities in a series of bimetallic-electrode systems with a distance between the two electrodes of 21.7 a.u. are further investigated. Spin-polarized calculations of electron density for nonmagnetic and magnetic bimetallic-electrode systems are compared. Our work is helpful for first principles investigation of spin-dependent metal-molecule-metal tunneling junctions.
Improving electrical characteristics of W/HfO2/In0.53Ga0.47As gate stacks by altering deposition techniques
(2011-07-01)
Zade, D.
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Kakushima, K.
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Kanda, T.
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Lin, Y. C.
;
Ahmet, P.
The effects of controlling InGaAs substrate temperature during electron beam deposition of HfO2 on electrical characteristics of W/HfO2/n-In0.53Ga0.47As capacitors are investigated. It is found that by depositing a thin HfO2 layer at the interface when substrate temperature is raised to 300 degrees C, frequency dispersion at depletion and accumulation conditions is reduced and interface state density is lowered regardless of the HfO2 thickness. Cross-sectional transmission electron microscopy images have revealed that the formation of mesoscopic voids in the InGaAs substrate near the interface is suppressed with HfO(2)deposition at 300 degrees C at the interface. A band diagram with an additional bulk trap energy level has been proposed to explain the frequency dispersion and conductance peaks at accumulation condition. (c) 2011 Elsevier B.V. All rights reserved.
Improved characteristics for Pd nanocrystal memory with stacked HfAlO-SiO2 tunnel layer
(2011-07-01)
Kang, Tsung-Kuei
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Liu, Han-Wen
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Wang, Fang-Hsing
;
Lin, Cheng-Li
;
Liao, Ta-Chuan
Stacked HfAlO-SiO2 tunnel layers are designed for Pd nanocrystal nonvolatile memories. For the sample with 1.5 nm-HfAlO/3.5 nm-SiO2 tunnel layer, a smaller initial memory window is obtained compared to the sample with 3.5 nm-HfAlO/1.5 nm-SiO2 tunnel layer. Owing to the thermally induced traps in HfAlO-SiO2 films are located at a farther distance from the Si substrate and more effective blocking of charge leakage by asymmetric tunnel barrier, a larger final memory window and better retention characteristic can be obtained for Al/blocking oxide SiO2/Pd NC5/1.5 nm-HfAlO/3.5 nm-SiO2/Si structure. A N-2 plasma treatment can further improve the memory characteristics. Better memory characteristics can be obtained for Pd-nanocrystal-based nonvolatile memory with an adequate thickness ratio of HfAlO to SiO2. (C) 2011 Elsevier Ltd. All rights reserved.
PAComplex: a web server to infer peptide antigen families and binding models from TCR-pMHC complexes
(2011-07-01)
Liu, I-Hsin
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Lo, Yu-Shu
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Yang, Jinn-Moon
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生物科技學系
;
生物資訊及系統生物研究所
One of the most adaptive immune responses is triggered by specific T-cell receptors (TCR) binding to peptide-major histocompatibility complexes (pMHC). Despite the availability of many prediction servers to identify peptides binding to MHC, these servers are often lacking in peptide-TCR interactions and detailed atomic interacting models. PAComplex is the first web server investigating both pMHC and peptide-TCR interfaces to infer peptide antigens and homologous peptide antigens of a query. This server first identifies significantly similar TCR-pMHC templates (joint Z-value >= 4.0) of the query by using antibody-antigen and protein-protein interacting scoring matrices for peptide-TCR and pMHC interfaces, respectively. PAComplex then identifies the homologous peptide antigens of these hit templates from complete pathogen genome databases (>= 10(8) peptide candidates from 864 628 protein sequences of 389 pathogens) and experimental peptide databases (80 057 peptides in 2287 species). Finally, the server outputs peptide antigens and homologous peptide antigens of the query and displays detailed interacting models (e.g. hydrogen bonds and steric interactions in two interfaces) of hitTCR-pMHC templates. Experimental results demonstrate that the proposed server can achieve high prediction accuracy and offer potential peptide antigens across pathogens. We believe that the server is able to provide valuable insights for the peptide vaccine and MHC restriction. The PAComplex sever is available at http://PAcomplex.life.nctu.edu.tw.
Characterisation of a suspended nanowire channel thin-film transistor with sub-100 nm air gap
(2011-07-01)
Kuo, Chia-Hao
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Hsu, Chia-Wei
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Lin, Horng-Chih
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Huang, Tiao-Yuan
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電子工程學系及電子研究所
A novel suspended nanowire (NW) channel thin-film transistor (TFT) with sub-100 nm air gap has been fabricated and characterised. With a simple and low-cost over-etching-time-controlled reactive ion etching technique and a buffered-oxide etch wet-etching process, a suspended NW of 27 nm and an air gap of 10 nm were achieved. The resultant suspended-NW-channel TFTs showed an ultra-low subthreshold swing (52 mV/dec) and considerable hysteresis window (3.7 V). Finally, the impacts of device dimensions on the characteristics of suspended NW TFTs were also investigated.
High-Quality 1 eV In0.3Ga0.7As on GaAs Substrate by Metalorganic Chemical Vapor Deposition for Inverted Metamorphic Solar Cell Application
(2011-07-01)
Hong Quan Nguyen
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Chang, Edward Yi
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Yu, Hung Wei
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Lin, Kung Liang
;
Chung, Chen Chen
In0.3Ga0.7As layers were grown by metalorganic chemical vapor deposition using step graded buffer layers on different misoriented GaAs(001) substrates. Smooth-surface In0.3Ga0.7As film with a root mean square roughness of 1.9 nm was obtained with the growth temperature of 490 degrees C using a 10-step graded parabolic-like indium profile buffer layer on the surface with the 6 degrees-off cut toward the [111] direction. The threading dislocation density in the film was determined to be 1.2 x 10(6) cm(-2) by transmission electron microscopy. The photoluminescence results obtained at 300 and 77K indicate that very low recombination centers existed in the epilayer. (C) 2011 The Japan Society of Applied Physics
Bidirectional colorless wired and wireless WDM-PON with improved dispersion tolerance for radio over fiber
(2011-07-01)
Xu, L.
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Chow, C. W.
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Tsang, H. K.
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光電工程學系
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Department of Photonics
We propose and demonstrate a bidirectional transmission, hybrid wired and wireless access network based on subcarrier modulation (SCM) techniques. The scheme simultaneously enables the dispersion-tolerant transmission of millimeter (mm)-wave signals for use in wireless access networks, downstream baseband signals for optical wired access networks, and optical continuous-wave (CW) carriers for use in upstream data remodulations. Error-free transmissions through a 25-km length of single mode fiber (SMF) for both the downstream baseband and the remodulated upstream signals are confirmed by bit-error-rate (BER) measurements. The dispersion tolerance of the radio-over-fiber (RoF) signal is assessed using numerical simulations. (c) 2011 Elsevier B.V. All rights reserved.
A corpus-based approach to online materials development for writing research articles
(2011-07-01)
Chang, Ching-Fen
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Kuo, Chih-Hua
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英語教學研究所
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Institute of Teaching English to speakers of other Languages
There has been increasing interest in the possible applications of corpora to both linguistic research and pedagogy. This study takes a corpus-based, genre-analytic approach to discipline-specific materials development. Combining corpus analysis with genre analysis makes it possible to develop teaching materials that are not only authentic but also research-supported. An RA corpus consisting of 60 research articles from three major journals of computer science was constructed. A word frequency list derived from the corpus was analyzed to develop a vocabulary profile for the genre. Move analysis was also conducted based on a self-developed coding scheme of rhetorical moves in the target genre. The move codes were tagged in the corpus texts so that individual moves and move patterns could be retrieved for the purpose of developing research-based online teaching materials for graduate students of computer science. Numerous examples of specialized vocabulary, grammatical usage, and move structures that showcase and characterize academic computer science discourse were used in not only lessons but also learning tasks, discussion topics, and online writing models. The paper ends with a discussion of the usefulness and effectiveness of the online RA writing materials, based on student feedback and assessments. (C) 2011 Elsevier Ltd. All rights reserved.
On the Origin of Gate-Induced Floating-Body Effect in PD SOI p-MOSFETs
(2011-07-01)
Dai, Chih-Hao
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Chang, Ting-Chang
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Chu, An-Kuo
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Kuo, Yuan-Jui
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Jian, Fu-Yen
This letter systematically investigates the origin of gate-induced floating-body effect (GIFBE) in partially depleted silicon-on-insulator p-type MOSFETs. The experimental results indicate that GIFBE causes a reduction in the electrical oxide field, leading to an underestimate of negative-bias temperature instability degradation. This can be partially attributed to the electrons tunneling from the process-induced partial n(+) polygate. However, based on different operation conditions, we found that the dominant origin of electrons was strongly dependent on holes in the inversion layer under source/drain grounding. This suggests that the mechanism of GIFBE at higher voltages is dominated by the proposed anode electron injection model, rather than the electron valence band tunneling widely accepted as the mechanism for n-MOSFETs.
Passivation of yellow luminescence defects in GaN film by annealing and CF(4) plasma treatment
(2011-07-01)
Chen, Hsiang
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Kao, Chyuan-Haur
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Chen, Yi-Chen
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Lo, Hong-Kai
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Yeh, Yih-Min
In this study, we demonstrated that yellow luminescence (YL) defects can be mitigated with proper annealing or CF(4) plasma treatment. Multiple material analyses, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and surface roughness measurements were performed to investigate improvements in GaN film material properties caused by annealing and CF(4) plasma treatment. Filling vacancies during the annealing process and incorporating fluorine atoms to bond with dangling bonds during the plasma treatment process may lessen YL defects and decrease YL luminescence.
健身系統
(2011-07-01)
楊秉祥
;
陳廷昇
;
周松緯
;
吳欣恬
一種健身系統，其結合生物力學與神經生理量測，提供使用者根據健身目標，特別是針對特定的肌肉群，給予即時回饋，提供適當之修正運動模式或運動強度建議，增加健身效率與避免運動傷害。
Effect of Oxygen Annealing on the Ultraviolet Photoresponse of p-NiO-Nanoflower/n-ZnO-Nanowire Heterostructures
(2011-07-01)
Yang, Po-Yu
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Wang, Jyh-Liang
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Tsai, Wei-Chih
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Wang, Shui-Jinn
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Lin, Jia-Chuan
A transparent ultraviolet (UV) sensor using nanoheterojunctions (NHJs) composed of p-type NiO nanoflowers (NFs) and n-type ZnO nanowires (NWs) was prepared through a sequential low-temperature hydrothermal-growth process. The devices that were annealed in an oxygen (O(2)) ambient exhibited better rectification behavior (l(forward)/l(reverse) = 427), a lower forward threshold voltage (V(th) = 0.98 V), a lower leakage current (1.68 x 10(-5) A/cm(2)), and superior sensitivity (l(UV)/l(dark) = 57.8; l(visible)/l(dark) = 1.25) to UV light (lambda = 325 nm) than the unannealed devices. The remarkably improved device performances and optoelectronic characteristics of the annealed p-NiO-NF/n-ZnO-NW NHJs can be associated with their fewer structural defects, fewer interfacial defects, and better crystallinity. A stable and repeatable operation of dynamic photoresponse was also observed in the annealed devices. The excellent sensitivity and repeatable photoresponse to UV light of the hydrothermally grown p-NiO-NF/n-ZnO-NW NHJs annealed in a suitable O(2) ambient indicate that they can be applied to nano-integrated optoelectronic devices.
Elucidating the Physical Property of the InGaN Nanorod Light-Emitting Diode: Large Tunneling Effect
(2011-07-01)
Lee, Ya-Ju
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Lee, Chia-Jung
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Chen, Chih-Hao
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Lu, Tien-Chang
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Kuo, Hao-Chung
The current-voltage (I-V) characteristics of the InGaN nanorod light-emitting diode (LED) are evaluated using nanoprobes installed on a field-emission scanning electron microscope. The saturated current of the InGaN nanorod LED (I(O) = 2 x 10(-9) A) is found to be orders of magnitude higher than those obtained by downscaling a conventional InGaN LED to a chip size of 300 x 300 mu m(2) (I(O1) = 1 x 10(-25) A; I(O2) = 1 x 10(-14) A). This observation is explained by the fact that the nanorod LED is associated with enhanced tunneling of injected carriers and, therefore, reduction of the defect-assisted leakage current and the diffusion-recombination process that normally occurs in InGaN LEDs.
船舶價格與運費波動之關聯分析
(2011-07-01)
吳偉銘
;
洪榮良
;
Wei-Ming Wu
;
Jung-Liang Hung
;
Institute of Business and Management
本研究首先藉由Hedonic函數方法來建構綜合船價指數，以克服資料不對稱問題。之後，再以VAR模型來探討不定期海運市場中各價格波動間之關聯。本研究經由共整合分析發現：新造船、二手船、報廢船及貨運市場之價格波動，確實呈現環環相扣之連動關係，並且是一穩定之長期均衡關係。短期上，前期報廢船價波動，將可作為新造船與二手船價之先期變動指標。然面對市場價格體系之短期失衡時，貨運市場之調整最敏感，而新造船則較遲緩。另外，報廢船價波動干擾對二手船價之衝擊影響最直接且快速；相對的，運費波動干擾對二手船價之衝擊影響卻較溫和但深遠。另外，運費水準則受來自二手船價波動之衝擊影響最大。而報廢船舶價格之衝擊反應，主要是受來自貨運市場之價格波動影響。最後，新造船價之波動反應主要是反應影響造船成本之鋼鐵價格變動，所以其受報廢船價格波動之衝擊影響最大。
定位方法及應用其之通訊系統
(2011-07-01)
羅棨鐘
;
張哲賓
;
李岳峰
;
彭俊豪
;
郭聖博
一種通訊系統，用以支援在特定區域中之定位操作，其包括系統伺服電路及手持式通訊裝置。系統伺服電路接收對應至各m個位置訓練點之訓練點資料，m為大於1之自然數，並根據分別對應至m個位置訓練點之m筆訓練點資料轉換出第一組及第二組參數。手持式通訊裝置自系統伺服電路下載第一組及第二組參數之部分或全部；根據下載後之第一組及第二組參數之部分或全部建立定位函式；決定待測定位點之待測定位點資料；將待測定位點資料代入定位函式中，以產生對應至手持式通訊裝置之待測定位點的定位結果資料。
AUTHENTICATION AND CROSS-RECOVERY OF MULTIPLE IMAGES
(2011-07-01)
Chen, Lee Shu-Teng
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Chen, Shang-Kuan
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Lin, Ja-Chen
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資訊工程學系
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Department of Computer Science
This work presents an authentication and cross-recovery scheme to protect a group of n JPEG images. Given n images, the images are scaled down and then encoded using JPEG to create n recovery data. Based on a pre-determined threshold t, 2 <= t < n, the n recovery data are shared to create n shadows. Next, n authentication data are generated to identify malicious attacks on the system. Additionally, the n shadows and the n authentication data are embedded in the n JPEG codes of the n original images to form n JPEG stego codes, which can be stored in a distributed storage system. Moreover, in the daily maintenance of the storage system, the authentication data concealed inside these n JPEG stego codes are used to verify which ones have been attacked. If some (up to n - t) of the n JPEG stego codes are corrupted, the corrupted JPEG images can be recovered approximately using any t survived JPEG stego codes. Experimental results demonstrate the effectiveness of the proposed method. Comparisons with other image recovery methods are also included.
Dual Modulation Technique for High Efficiency in High-Switching Buck Converters Over a Wide Load Range
(2011-07-01)
Tsai, Jen-Chieh
;
Huang, Tsung-Ying
;
Lai, Wang-Wei
;
Chen, Ke-Horng
;
電控工程研究所
A dual modulation technique to improve power conversion efficiency with minimal increase in output voltage ripple is presented. The worsening switching noise caused by parasitic resistance and inductance due to high-switching operation can also be alleviated by the proposed ac ripple detector. Furthermore, the dual modulation method can speed up the load transient response since the switching frequency can increase to 5 MHz during the transient period. At very light loads, the switching frequency is always kept higher than the acoustic frequency to avoid noisy sound. Experiment results show that the converter operates at 5 MHz using a small inductor of 1 mu H. The load transient response time is shorter than 3 mu s when load current changes from 150 to 450 mA or vice versa. Power efficiency is kept higher than 85% over a wide load current range. Specifically, light efficiency can be raised to about 45% above that of the conventional design.