Browsing by Issue Date, starting with "2013-02-01"

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Recent trend in graphene for optoelectronics
(2013-02-01)
Chen, Yu-Bin
;
Liu, John S.
;
Lin, Pang
;
材料科學與工程學系
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Department of Materials Science and Engineering
This study analyzes the scientific knowledge diffusion paths of graphene for optoelectronics (GFO), where graphene offers wide applications due to its thinness, high conductivity, excellent transparency, chemical stability, robustness, and flexibility. Our investigation is based on the main path analysis which establishes the citation links among the literature data in order to trace the significant sequence of knowledge development in this emerging field. We identify the main development paths of GFO up to the year 2012, along which a series of influential papers in this field are identified. The main path graph shows that knowledge diffusion occurs in key subareas, including reduced graphene oxide, chemical vapor deposition, and exfoliation techniques, which are developed for the preparation and applications of GFO. The applications cover solar cells, laser devices, sensing devices, and LCD. In addition, the main theme of GFO research evolves in sequence from small-graphene-sample preparation, to large-scale film growth, and onto prototype device fabrication. This evolution reflects a strong industrial demand for a new transparent-conductive film technology.
Freeway drivers' willingness to pay for an on board unit under an electronic toll collection system
(2013-02-01)
Jou, Rong-Chang
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Chiou, Yu-Chiun
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Kuo, Chung-Wei
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Tan, Hao-I
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運輸與物流管理系註：原交通所+運管所
Electronic toll collection (ETC) systems have been put into practice in one or two channels at toll plazas on Taiwan's freeways since 2006. The utilisation of the ETC system has been flat due to the extra cost of installing the on board unit (OBU) that is used in the system. To increase the utilisation rate of the ETC system, it is crucial to understand the real price that drivers are willing to pay. Therefore, this study investigates freeway drivers' willingness to pay a value for an OBU. A stated preference experiment is designed to obtain the willingness to pay at three different levels of use. To avoid the estimation bias due to a large percentage with a zero willingness to pay, a spike model is used. Different markets are segmented to examine their willingness to pay for an OBU. The estimation results show that the willingness to pay for an OBU is NT$727/unit(1) for short distance drivers, NT$830 for medium distance drivers, and NT$1308/unit for long distance drivers. (C) 2012 Elsevier Ltd. All rights reserved.
Design of Bidirectional and Low Power Consumption Gate Driver in Amorphous Silicon Technology for TFT-LCD Application
(2013-02-01)
Zheng, Guang-Ting
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Liu, Po-Tsun
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Wu, Meng-Chyi
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Chu, Li-Wei
;
Yang, Meng-Chuan
A new gate driver has been designed and fabricated by amorphous silicon (a-Si) technology. With utilizing four clock signals in the design of gate driver on array (GOA), the pull-up transistor has ability for both output charging and discharging, and layout size of the proposed gate driver can be narrowed for bezel panel application. Moreover, lower duty cycle of clock signals can decrease static power loss to further reduce the overall power consumption of the proposed gate driver. The scan direction of the proposed gate driver can be adjusted by switching two direct control signals to present the reversal display of image. The proposed gate driver has been successfully demonstrated in a 4.5-inch WVGA (480 x RGB x 800) TFT-LCD panel and passed reliability tests of the supporting foundry.
RISE: A RelIable and SEcure Scheme for Wireless Machine to Machine Communications
(2013-02-01)
Ren, Wei
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Yu, Linchen
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Ma, Liangli
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Ren, Yi
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資訊工程學系
Wireless Machine to Machine (M2M) communications enable ubiquitous sensing, controlling, and acting via sensors, actuators, and actors. Reliability and security are of foremost importance in wireless M2M systems. A simple, target distinguishing attack can result in M2M\'s failure. This paper presents a RelIable and SEcure scheme, RISE, which is a package of policies that guarantee the reliability of data (including sensor reports and actuator instructions) and devices (including sensors, actuators, and actors). The data reliability is improved by four algorithms, ChooseMedian, ChooseMost, ChooseNearest, and Trust-based Enhancement. Report attainability is improved via m repeat-sending and n multiple-reporting algorithms. Device reliability is guaranteed by device-indistinguishability, which comprises data-indistinguishability and behavior-indistinguishability. The security requirements are formally defined, and the security analysis proves the soundness and completeness of the scheme.
CRLH Leaky Wave Antenna Based on ACPS Technology With 180 degrees Horizontal Plane Scanning Capability
(2013-02-01)
Chi, Yu-Jen
;
Chen, Fu-Chiarng
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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
This study presents a novel composite right/left-handed (CRLH) leaky wave antenna (LWA) with horizontal plane scanning capability. This LWA consists of 10 CRLH unit cells and coplanar waveguide to coplanar stripline transitions. The proposed balanced CRLH unit cell is based on an asymmetric coplanar stripline structure (ACPS). The parameters of the CRLH unit cell can be determined analytically, enabling easy modification for any other frequency band. Because of its planar and horizontal plane scanning property, the proposed design can also be extended to a sector-shaped multisection LWA, achieving a scanning range of more than 180 in the horizontal plane. By varying the operating frequency, the CRLH leaky wave antenna shows the continuously beam-scanning property from backward to forward in the horizontal plane. A 10-cell prototype exhibits the beam-scanning capability in the horizontal plane, and a 20-cell multisection sector-shaped LWA confirms the approach of designing the wide-range beam-scanning LWA. Experimental results show that the proposed design is in good agreement with the simulation. The planar and low-profile characteristics of the novel CRLH LWA make it suitable for integration with other microwave circuits, and can be applied to applications that require a wider beam-scanning range.
A 2-bit/Cell Gate-All-Around Flash Memory of Self-Assembled Silicon Nanocrystals
(2013-02-01)
Chen, Hung-Bin
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Chang, Chun-Yen
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Hung, Min-Feng
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Tang, Zih-Yun
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Cheng, Ya-Chi
This work presents gate-all-around (GAA) polycrystalline silicon (poly-Si) nanowires (NWs) channel poly-Si/SiO2/Si3N4/SiO2/poly-Si (SONOS) nonvolatile memory (NVM) with a self-assembled Si nanocrystal (Si-NC) embedded charge trapping (CT) layer. Fabrication of the Si-NCs is simple and compatible with the current flash process. The 2-bit operations based on channel hot electrons injection for programming and channel hot holes injection for erasing are clearly achieved by the localized discrete trap. In the programming and erasing characteristics studies, the GAA structure can effectively reduce operation voltage and shorten pulse time. One-bit programming or erasing does not affect the other bit. In the high-temperature retention characteristics studies, the cell embedded with Si-NCs shows excellent electrons confinement vertically and laterally. With respect to endurance characteristics, the memory window does not undergo closure after 10(4) program/erase (P/E) cycle stress. The 2-bit operation for GAA Si-NCs NVM provides scalability, reliability and flexibility in three-dimensional (3D) high-density flash memory applications. (C) 2013 The Japan Society of Applied Physics
Cost-Effective and Self-Textured Gallium-Doped Zinc Oxide Front Contacts for Hydrogenated Amorphous Silicon Thin-Film Solar Cells
(2013-02-01)
Yu, Shu-Hung
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Ho, Po-Ching
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Lee, Chia-Ling
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Bi, Chien-Chung
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Yeh, Chih-Hung
We adopt a economical and original method to fabricate self-textured gallium-doped zinc oxide (GZO) front contacts for hydrogenated amorphous silicon (a-Si: H) single-junction solar cells. This technique involves an atmospheric-pressure plasma jet (APPJ) and a dc sputtering process. The electro-optical characteristics of the textured GZO films are mainly controlled by the haze of organosilicon underlayers deposited by the APPJ. The films exhibit an average optical transmittance of about 80% and resistivity below 9.91 x 10(-4) Omega cm. Moreover, compared with flat solar cells, textured cells fabricated on moderate GZO front contacts show 7.9 and 10.9% enhancements in conversion efficiency and short-circuit current density, respectively. (C) 2013 The Japan Society of Applied Physics
基地台搜尋裝置及其搜尋方法
(2013-02-01)
王奕翔
;
陳紹基
一種基地台搜尋裝置及其搜尋方法,前述基地台搜尋裝置接收由基地台所傳送之複數個時域接收訊號,每個時域接收訊號具有一相對應同步訊號序列。前述基地台搜尋裝置包括快速傅利葉轉換器、關聯運算單元、選擇裝置及決策裝置。快速傅利葉轉換用以轉換接收機所接收到的時域訊號。關聯運算單元根據一控制訊息處理頻域接收訊號之一自相關運算。選擇裝置根據每一個同步訊號序列中相鄰子載波之關係,來產生一選擇訊號,以執行一降低基地台搜尋運算量之程序。決策裝置尋找接收訊號與各同步訊號序列關聯値之最大値,以找出同步訊號序列編碼與整數載波頻率偏移。
Product market competition and credit risk
(2013-02-01)
Huang, Hsing-Hua
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Lee, Han-Hsing
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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
This study theoretically and empirically investigates effects of product market competition on credit risk. We first develop a real-options-based structural model in a homogeneous oligopoly and show that credit spreads are positively related to the number of firms in an industry. The disparity of firm size in an industry is relevant to both product market competition and credit risk, and we therefore extend the model to an asymmetric duopoly case. In particular, we demonstrate that credit spreads of relatively small (large) firms within an industry are positively (negatively) related to Herfindahl-Hirschman index, and the relative firm size in an industry is an important determinant of credit risk. The models' implications are empirically scrutinized by a reduced-form hazard model and generally supported. By performing out-of-sample analyses, the results demonstrate that firm size together with the interaction terms between intra-industry firm size dummies and competition intensity can effectively predict default. (C) 2012 Elsevier B.V. All rights reserved.
Investigation of organelle-specific intracellular water structures with Raman microspectroscopy
(2013-02-01)
Tiwari, Shraeddha
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Ando, Masahiro
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Hamaguchi, Hiro-o
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應用化學系
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應用化學系分子科學碩博班
The study of intracellular water in living cells is a challenge of fundamental importance. While the critical roles of water in maintaining and propagating life have been widely recognized and accepted, our understanding of water/biomolecule interactions is surprisingly limited. Using Raman microspectroscopic imaging of a living yeast cell followed by a multivariate analysis in form of the nonnegative matrix factorization method, we successfully resolve organelle-specific water structures. The intensities and the band profiles of the segregated water OH stretch spectra yield important and otherwise unobtainable information on the extensive effect of the water/biomolecule interactions in a given organelle on the hydrogen-bonding network of water molecules. Copyright (C) 2012 John Wiley & Sons, Ltd.
Influence of the GaN capping thickness on the strain and photoluminescence properties of InN/GaN quantum dots
(2013-02-01)
Ke, Wen-Cheng
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Wu, Yue-Han
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Houng, Wei-Chung
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Wei, Chih-An
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材料科學與工程學系
InN quantum dots (QDs) were grown on 1 mu m thick GaN/(0001) sapphire substrates by low pressure metal organic chemical vapor deposition. A single crystalline 10-nm thick GaN capping layer was achieved on the InN QDs by the flow-rate modulation epitaxy method at 650 degrees C. The (002) omega/2 theta scans of the X-ray diffraction measurements show that the reduction of the lattice constant with a capping thickness indicate that the GaN capping process exerts a compressive strain on the InN QDs. The residual strain was reduced from 0.245% to -0.245% as the GaN cap thickness increases from 0 to 20 nm. In addition, the analysis of the photoluminescence peak energy estimated that the free electron concentration (i.e. density of indium (In) vacancy) decreased from 1.62x10(18) cm(-3) to 1.24x10(18) cm(-3). The suggestion here is that the increase of the compressive strain on InN QDs due to the increased GaN capping layer thickness provides the high driving force for the interdiffusion of the In atom and gallium (Ga) atoms between the interface of InN QDs and the GaN capping layer. Thus, we believe that more Ga atoms can diffuse from the GaN capping layer and substitute the high density of In vacancy in the InN QDs, resulting in a decrease of the free electron concentration in the InN QDs with the increase in the GaN capping layer thickness. (C) 2012 Elsevier B.V. All rights reserved.
Improved photoconductive properties of composite nanofibers based on aligned conjugated polymer and single-walled carbon nanotubes
(2013-02-01)
Massuyeau, Florian
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Zhao, Yuanchun
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El Mel, Abdel Aziz
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Yaya, Abu
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Geschier, Frederic
We successfully address the challenge of aligning single-walled carbon nanotubes (SWNTs) and conjugated polymer chains in composite nanofibers for enhancing their opto-electrical properties. A pore-filling template strategy has been developed to prepare such nanocomposites from SWNTs and poly(para-phenylene vinylene) (PPV) chains, with both species well-oriented aligned along the pore axis. Addition of the SWNTs leads to a remarkable increase in photocurrent of four orders of magnitude as compared to equivalent pristine PPV nanofibers. Further analysis indicates that the strong photocurrent enhancement is not simply an effect of alignment, but additionally benefits from alignment-enhanced interaction of polymer chains with SWNTs, as supported by density functional theory (DFT) calculations.
生醫電波感測器
(2013-02-01)
陳昱翰
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趙昌博
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廖倫德
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林進燈
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陳建廷
一種生醫電波感測器，包括一底座、一中心軸、一乾式電極、一外殼、複數個支架。當中心軸降下時，凸出底座下表面的支架向外輻射展開以撥開一受試者之毛髮，且乾式電極露出於外殼並與受試者之皮膚接觸，以量測受試者之一生醫電波訊號。本發明可克服毛髮造成之訊號阻隔問題，而達成生醫電波訊號之量測。
Characteristic of p-Type Junctionless Gate-All-Around Nanowire Transistor and Sensitivity Analysis
(2013-02-01)
Han, Ming-Hung
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Chang, Chun-Yen
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Jhan, Yi-Ruei
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Wu, Jia-Jiun
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Chen, Hung-Bin
The characteristics and sensitivities of p-type junctionless (JL) gate-all-around (GAA) (JLGAA) nanowire transistors are demonstrated by simulating a 3-D quantum transport device with a view to their use in CMOS technology. The concentration of dopants in a p-type JL nanowire transistor is not as high as that in an n-type device owing to solid solubility of boron in silicon. However, we can use a midgap material as gate electrode to design an appropriate device threshold voltage. The p-type JLGAA transistor exhibits a favorable on/off current ratio and better short-channel characteristics than a conventional inversion-mode transistor with a GAA structure. Sensitivity analyses reveal that the channel thickness and random dopant fluctuation substantially affect the device performance in terms of threshold voltage (V-th), on current (I-on), and subthreshold slope because of the full depletion condition of the channel. The channel length and oxide thickness have less impact because the short-channel effect is well controlled.
Sustainable consumption, production and infrastructure construction for operating and planning intercity passenger transport systems
(2013-02-01)
Chiou, Yu-Chiun
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Lan, Lawrence W.
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Chang, Kai-Lin
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運輸與物流管理系註：原交通所+運管所
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Department of Transportation and Logistics Management
Two bi-level programming models-an operational model and a planning model-for the intercity passenger transport systems under sustainability contexts are proposed in this study. In the upper-level models, the government (regulator) aims to provide the transport infrastructures and to regulate the fares (tolls) to achieve some sustainability objectives, indexed by energy consumption, air pollution, traffic safety, and travel time. In the lower-level models, the transport carriers aim to determine the service frequencies to maximize their profits; whereas the users aim to choose available transport modes to maximize their utilities. The rationales for the proposed models are based on the behavioral conjectures in game theory. A case of 400-km intercity passenger transport (e.g., Taipei-Kaohsiung in the western corridor of Taiwan) is exemplified with sensitivity analysis. The results indicate that rail transport is the priority mode toward overall sustainability for intercity passenger transport. Based on the results, some policy implications are addressed. (C) 2010 Elsevier Ltd. All rights reserved.
Large-Swing-Tolerant ESD Protection Circuit for Gigahertz Power Amplifier in a 65-nm CMOS Process
(2013-02-01)
Lin, Chun-Yu
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Tsai, Shiang-Yu
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Chu, Li-Wei
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Ker, Ming-Dou
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電子工程學系及電子研究所
The signal swing at output pad of some radio-frequency (RF) power amplifiers (PAs) may be higher than the supply voltage. To protect the gigahertz large-swing power amplifier from electrostatic discharge (ESD) damage in nanoscale CMOS process, a large-swing-tolerant ESD protection circuit is presented in this paper. The proposed ESD protection circuit had been designed, fabricated, and characterized in a 65-nm CMOS process, where it can achieve low parasitic capacitance, large swing tolerance, high ESD robustness, and good latchup immunity. The proposed ESD protection circuit had been further applied to a 2.4-GHz PA to provide 3-kV human-body-model (HBM) ESD robustness without degrading the RF performances.
Nonvolatile floating gate memory characteristics of Sb2Te-SiO2 nanocomposite thin films
(2013-02-01)
Yang, Cheng-Hsun
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Chiang, Kuo-Chang
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Hsieh, Tsung-Eong
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材料科學與工程學系
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Department of Materials Science and Engineering
Nonvolatile floating gate memory (NFGM) device composed of Sb2Te nanocrystals (NCs) as the charge-storage traps embedded in SiO2 matrix was prepared by the target-attachment sputtering method at various nitrogen (N-2) incorporation conditions. Via post annealing at 450 degrees C in ambient air, the sample prepared at the condition N-2/Ar=0.1 exhibited a maximum memory window (Delta V-FB) shift=4.4 V and charge density=4.2x10(12) cm(-2) under +/- 7 V gate voltage sweep. N-2 incorporation not only reduced the Sb2Te NC size to about 5 nm, but also suppressed the oxygen defects and antimony oxides in the sample. Feasibility of the Sb2Te chalcogenide NCs to NFGM fabrication with the simplified process and relatively low annealing temperature is demonstrated. (C) 2012 Elsevier B.V. All rights reserved.
波長多工兼具位移多工之全像式儲存裝置
(2013-02-01)
蘇威佳
;
陳彥宏
;
鍾德元
本發明係揭露一種波長多工兼具位移多工之全像式儲存裝置，其係包含一儲存媒體與複數道訊號光束，而每一訊號光束係具有不同的波長，並可照射至儲存媒體，另外還有至少一參考光束，可照射至儲存媒體上，並與複數道訊號光束依序形成一干涉圖案而分別記錄於儲存媒體之不同位置及不同深度的儲存層中。本發明不僅可以提高資料的存取速度，而且可以大量增加儲存容量。
無線通訊系統之空間預編碼方法、系統、發射器及接收器
(2013-02-01)
蔡尚澕
一種無線通訊系統之空間預編碼方法包含：發射器將一傳送符號複製成N個傳送符號；每一傳送符號乘上一迴授之相位旋轉以得到N個傳送符號向量；將N個傳送符號向量以N個天線傳送至一多重輸入多重輸出通道；接收器以M個天線接收到M個接收符號向量，並將其乘上一共軛轉置之通道矩陣以及分別乘上相對應之一逆相位旋轉後加總得到一等比例符號；以及從等比例符號中移除通道增益影響以解出傳送符號。同時亦揭露一種實現上述方法之空間預編碼系統、發射器以及接收器。
Wide Tunning Range 60 GHz VCO and 40 GHz DCO Using Single Variable Inductor
(2013-02-01)
Lu, Tai-You
;
Yu, Chi-Yao
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Chen, Wei-Zen
;
Wu, Chung-Yu
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電子工程學系及電子研究所
This paper presents a 60 GHz, 16% tuning range VCO, and a 40 GHz, 18 bits, 14% tuning range DCO incorporating variable inductor (VID) techniques. The variable inductor, consisting of a transformer and a variable resistor, is tunable by adjusting its resistor. By employing the proposed frequency tuning scheme, wide-tuning range as well as multi-band operation are achieved without sacrificing their operating frequencies. To verify the operation principles, the VCO and DCO are both fabricated in 90 nm CMOS technology. The tuning range of VCO is from 52.2 GHz to 61.3 GHz. The measured phase noise from a 61.3-GHz carrier is about -118.75 dBc/Hz at 10-MHz offset, and the output power is -6.6 dBm. It dissipates 8.7 mW from a 0.7-V supply, and the chip size is 0.28 x 0.36 mm(2). On the other hand, the DCO is capable of covering frequency range from 37.6 GHz to 43.4 GHz. The measured phase noise from a 43 GHz carrier is about -109 dBc/Hz at 10-MHz offset, and the output power is -11 dBm. The DCO core dissipates 19 mW from a 1.2-V supply. Chip size is 0.5 x 0.15 mm(2).