Browsing by Issue Date, starting with "2011-01-15"

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Topological dynamics for multidimensional perturbations of maps with covering relations and Liapunov condition
(2011-01-15)
Li, Ming-Chia
;
Lyu, Ming-Jiea
;
應用數學系
;
Department of Applied Mathematics
In this paper, we study topological dynamics of high-dimensional systems which are perturbed from a continuous map on R(m) x R(k) of the form (1(x), g(x, y)). Assume that f has covering relations determined by a transition matrix A. If g is locally trapping, we show that any small C(0) perturbed system has a compact positively invariant set restricted to which the system is topologically semi-conjugate to the one-sided subshift of finite type induced by A. In addition, if the covering relations satisfy a strong Liapunov condition and g is a contraction, we show that any small C(1) perturbed homeomorphism has a compact invariant set restricted to which the system is topologically conjugate to the two-sided subshift of finite type induced by A. Some other results about multidimensional perturbations of f are also obtained. The strong Liapunov condition for covering relations is adapted with modification from the cone condition in Zgliczynski (2009) [11]. Our results extend those in Juang et al. (2008) [1], Li et al. (2008) [2]. Li and Malkin (2006) [3]. Misiurewicz and Zgliczynski (2001) [4] by considering a larger class of maps f and their multidimensional perturbations, and by concluding conjugacy rather than entropy. Our results are applicable to both the logistic and Henon families. (C) 2010 Elsevier Inc. All rights reserved.
Study of the internal quantum efficiency of InGaN/GaN UV LEDs on patterned sapphire substrate using the electroluminescence method
(2011-01-15)
Wang, C. H.
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Ke, C. C.
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Chiu, C. H.
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Li, J. C.
;
Kuo, H. C.
Internal quantum efficiency (IQE) of InGaN/GaN UV LEDs with patterned sapphire substrates (PSS) was investigated using electroluminescence (EL) and photoluminescence (PL) methods. The physical mechanisms that affect temperature-dependent EL efficiency as a function of injected carrier density were deduced. In order to reduce the density of non-radiative recombination centers to improve quantum efficiency, improvement of crystal quality and reduction in the number of defects are necessary. PSS LEDs showed better EL characteristics than non-PSS LEDs because of the improved epitaxial quality. Contrary to PL IQE, EL IQE was significantly affected by carrier injection efficiency, especially at low temperature when high bias voltage was applied to the p-n junction. Crown Copyright (C) 2010 Published by Elsevier B.V. All rights reserved.
A survey of energy efficient MAC protocols for IEEE 802.11 WLAN
(2011-01-15)
Tsao, Shiao-Li
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Huang, Chung-Huei
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資訊工程學系
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Department of Computer Science
In recent years, IEEE 802.11 wireless local area networks (WLANs) have been widely deployed, and more and more mobile devices have built-in WLAN interfaces. However, WEAN employs the carrier sense multiple access with collision avoidance (CSMA/CA) medium access control (MAC) protocol, which consumes a significant portion of the energy resources of a mobile device. Hence, minimizing the energy consumption of the WLAN interface in mobile devices has recently attracted considerable interest in both academia and industry. This article provides a survey and an experimental study of the energy consumption issues and energy-efficient technologies of the MAC protocol in IEEE 802.11 WLAN. (C) 2010 Elsevier B.V. All rights reserved.
Synthesis and characterization of semicarbazone of p-hydroxy-3-methoxy acetophenone (SPH3MA) single crystal
(2011-01-15)
Janarthanan, S.
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Rajan, Y. C.
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Umarani, P. R.
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Selvakumar, S.
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Pandi, S.
Single crystals of semicarbazone of p-hydroxy-3-methoxy acetophenone (SPH3MA) were grown by a slow evaporation solution growth technique at room temperature. This is the first report in the literature on the crystallization of SPH3MA. The cell parameters of the grown crystals were estimated by single crystal X-ray diffraction analysis. The various planes of reflection were identified from the XRD powder pattern. The presence of functional groups was identified from FTIR and (1)H NMR. The results were found to be in accordance with the structure of the crystal. The formation of charge transfer complex was confirmed by UV-vis-NIR spectroscopy. The thermal stability of the grown crystal was studied by thermal analysis. (C) 2010 Elsevier B.V. All rights reserved.
Octave-spanning carrier-envelope phase stabilized visible pulse with sub-3-fs pulse duration
(2011-01-15)
Okamura, Kotaro
;
Kobayashi, Takayoshi
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電子物理學系
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Department of Electrophysics
The visible second harmonic of the idler output from a noncollinear optical parametric amplifier was compressed using adaptive dispersion control with a deformable mirror. The amplifier was pumped by and seeded in the signal path by a common 400 nm second-harmonic pulse from a Ti:sapphire regenerative amplifier. Thus, both the idler output and the second harmonic of the idler were passively carrier-envelope phase stabilized. The shortest pulse duration achieved was below 3 fs. (C) 2011 Optical Society of America
Assessment of interface roughness during plasma etching through the use of real-time ellipsometry
(2011-01-15)
Han, Chien-Yuan
;
Lai, Chien-Wen
;
Chao, Yu-Faye
;
Leou, Ke-Ciang
;
Lin, Tsang-Lang
Real-time in situ ellipsometry was used to investigate the etching of SiO(2)/silicon wafers with a high concentration of Cl(2). We monitored the temporal trajectory of the ellipsometric parameter Delta and then selected several points for ex situ study using atomic force microscopy (AFM). There was a clearly observable transition period in the trajectory near the endpoint of the SiO(2)/Si interface. We studied the relationship between the ellipsometric parameter Delta and the same point in the AFM ex situ measurements. Three stages, thin film, the interface layer, and the substrate, were analyzed in this work. (C) 2010 Elsevier B.V. All rights reserved.
Material characteristics of InGaN based light emitting diodes grown on porous Si substrates
(2011-01-15)
Deng, Dongmei
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Chiu, Ching-Hsueh
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Kuo, Hao-Chung
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Chen, Peng
;
Lau, Kei May
InGaN/GaN multiple quantum wells light emitting diodes (LEDs) with 2 mu m thick crack-free GaN buffer layers were grown on porous Si substrates by metalorganic chemical vapor deposition. The material properties of LEDs grown on porous Si were studied in comparison with LEDs grown on grid-patterned Si. The (1 0 (1) over bar 5) asymmetric reciprocal space mapping (RSM) results indicate that LEDs grown on porous Si have less lattice tilt or distortion than those grown on grid-patterned Si. Both RSM and micro-photoluminescence (micro-PL) measurements suggest that multiple quantum wells grown on porous Si are less stressed. Mechanisms behind this partial strain relaxation are discussed. (C) 2010 Elsevier B.V. All rights reserved.
Epitaxial growth of titanium oxycarbide on MgO (001) substrates by pulsed laser deposition
(2011-01-15)
Do, Hien
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Yen, Tzu-Chun
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Tian, Chih-Sheng
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Wu, Yue-Han
;
Chang, Li
Epitaxial TiC(x)O(y) thin films were grown on MgO (0 0 1) substrates by using pulsed laser deposition method. High-resolution X-ray diffraction and transmission electron microscopy were used to examine crystallinity and microstructure of epitaxial TiC(x)O(y) film on MgO. The chemical composition of the film is determined to be x similar to 0.47 and y similar to 0.69 by X-ray photoelectron spectroscopy. Atomic force microscopy revealed that the surface of TiC(x)O(y) film is very smooth with roughness of 0.18 nm. The resistivity of the TiC(x)O(y) film measured by four-point-probe method was about 137 mu Omega cm. (C) 2010 Elsevier B.V. All rights reserved.
Label free sub-picomole level DNA detection with Ag nanoparticle decorated Au nanotip arrays as surface enhanced Raman spectroscopy platform
(2011-01-15)
Lo, Hung-Chun
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Hsiung, Hsin-I
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Chattopadhyay, Surojit
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Han, Hsieh-Cheng
;
Chen, Chia-Fu
Label free optical sensing of adenine and thymine oligonucleotides has been achieved at the sub-picomole level using self assembled silver nanoparticles (AgNPs) decorated gold nanotip (AuNT) arrays. The platform consisting of the AuNTs not only aids in efficient bio-immobilization, but also packs AgNPs in a three dimensional high surface area workspace, assisting in surface enhanced Raman scattering (SERS). The use of sub-10 nm AgNPs with optimum inter-particle distance ensures amplification of the chemically specific Raman signals of the adsorbed adenine, thymine, cytosine and guanine molecules in SERS experiments. High temporal stability of the Raman signals ensured reliable and repeatable DNA detection even after three weeks of ambient desk-top conservation. This facile architecture, being three dimensional and non-lithographic, differs from conventional SERS platforms. (C) 2010 Elsevier B.V. All rights reserved.
Nonpolar a-plane GaN grown on r-plane sapphire using multilayer AlN buffer by metalorganic chemical vapor deposition
(2011-01-15)
Chiang, C. H.
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Chen, K. M.
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Wu, Y. H.
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Yeh, Y. S.
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Lee, W. I.
Mirror-like and pit-free non-polar a-plane (11-20) GaN films are grown on r-plane (1-102) sapphire substrates using metalorganic chemical vapor deposition (MOCVD) with multilayer high-low-high temperature AlN buffer layers. The buffer layer structure and film quality are essential to the growth of a flat, crack-free and pit-free a-plane GaN film. The multilayer AlN buffer structure includes a thin low-temperature- deposited AlN (LT-AlN) layer inserted into the high-temperature-deposited AlN (HT-AlN) layer. The results demonstrate that the multilayer AlN buffer structure can improve the surface morphology of the upper a-plane GaN film. The grown multilayer AlN buffer structure reduced the tensile stress on the AlN buffer layers and increased the compressive stress on the a-plane GaN film. The multilayer AlN buffer structure markedly improves the surface morphology of the a-plane GaN film, as revealed by scanning electron microscopy. The effects of various growth V/III ratios was investigated to obtain a-plane GaN films with better surface morphology. The mean roughness of the surface was 1.02 nm, as revealed by atomic force microscopy. Accordingly, the multilayer AlN buffer structure improves the surface morphology and facilitates the complete coalescence of the a-plane GaN layer. (C) 2010 Elsevier B.V. All rights reserved.
Using silicon nanowire devices to detect adenosine triphosphate liberated from electrically stimulated HeLa cells
(2011-01-15)
Chen, C. C.
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Chen, Y-Z
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Huang, Y-J
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Sheu, J-T
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材料科學與工程學系奈米科技碩博班
In this study, we used a biosensor chip featuring Abl tyrosine kinase-modified silicon nanowire field-effect transistors (SiNW-FETs) to detect adenosine triphosphate (ATP) liberated from HeLa cells that had been electrically stimulated. Cells that are cultured in high-ionic-strength media or buffer environments usually undermine the sensitivity and selectively of SiNW-FET-based sensors. Therefore, we first examined the performance of the biosensor chip incorporating the SiNW-FETs in both low- and high-ionic-strength buffer solutions. Next, we stimulated, using a sinusoidal wave (1.0V, 50 Hz, 10 min), HeLa cells that had been cultured on a cell-culture chip featuring interdigitated electrodes. The extracellular ATP concentration increased by ca. 18.4-fold after electrical stimulation. Finally, we detected the presence of extracellular ATP after removing a small amount of buffer solution from the cell-cultured chip and introducing it into the biosensor chip. (C) 2010 Elsevier B.V. All rights reserved.
分心腦波量測分析方法及其應用系統
(2011-01-16)
林進燈
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柯立偉
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陳世安
;
邱添丁
;
王俞凱
本發明提供一種分心腦波量測分析方法及其應用系統，其係透過腦波量測與分析系統取得車輛駕駛者的數個腦波訊號，再使用主成分分析法(PCA)、獨立成分分析法(ICA)與傅立葉轉換對數個腦波訊號進行演算分析，以獲得一腦波誘發電位與/或觀測事件相關頻譜擾動(ERSP)圖表，分析腦波誘發電位與/或觀測事件相關頻譜擾動圖表是否有能量改變，如果是，則表示受測者正處於分心狀態，則由回饋系統提醒受測者，以避免受測者因分心所可能產生的反應延遲；以及如果否，則表示受測者無分心，繼續受測者的腦波量測與分析。
自我對準薄膜電晶體之製造方法及其結構
(2011-01-16)
周政偉
;
冉曉雯
;
蔡娟娟
一種自我對準薄膜電晶體之製造方法，首先提供具有相對的第一面與第二面之透明基板，並且依序沉積一氧化物閘極、介電層、及光阻層於透明基板的第一面上。接著，對基板的第二面照射紫外光，以對光阻層進行曝光，其中以氧化物閘極製成的閘極係做為光罩，並吸收照射至對應於氧化物閘極之光阻層的紫外光。接著移除曝光之光阻層，並沉積一透明導電層於未曝光之光阻層及介電層上。對透明導電層執行圖案化製程，以形成源極與汲極，並形成主動層覆蓋於源極、汲極、及介電層上，以完成一自我對準薄膜電晶體結構。
應用於大眾運輸系統中的網路連結建立方法
(2011-01-16)
曾建超
;
李勇昇
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張又仁
;
陳世揚
揭露一種應用於大眾運輸系統中的網路連結建立實施方法範例。預先建立一主代理器與一大眾運輸載具間之一第一通道。預先建立該主代理器與一拜訪代理器間之一第二通道。在該主代理器的協助下，該拜訪代理器預先授權給該大眾運輸載具，並分配該大眾運輸載具可用的一網路資源。在該主代理器的協助下，該大眾運輸載具預先得知該拜訪代理器所配置的該網路資源，而且，該大眾運輸載具預先完成對該拜訪代理器的一連結設定。當該大眾運輸載具移入一拜訪網路時，依預先完成的該連結設定，該大眾運輸載具與該拜訪代理器間建立網路連線。
通訊系統接收器及其解碼方法
(2011-01-16)
黃崇榮
;
宋志晟
;
李大嵩
針對K-Best演算法的缺失，提出一個適用於大型積體電路架構的高效率球型K-best解碼器。透過複數平面星座圖的規律特性來簡化星座點之搜尋，以及提出一高速平行比較之架構，省卻大量的資料排序動作及節點的運算量，藉以提供一高效率，低功率消耗且具有固定吞吐量的K-best解碼器。更進一步地，透過結合部份最大可能決策器與所提出的高效率搜尋演算法，使得在相同的環境及K值下，該系統能提供接近於最大可能搜尋之性能，且較傳統的K-Best接收機有更低的運算量。
包括奈米鑽石的載體及其製備的方法和用途
(2011-01-16)
趙瑞益
;
陳清漂
;
鄭嘉良
本發明提供一種包含奈米鑽石(ND)顆粒以及連接子的載體，其中，該奈米鑽石和該連接子係彼此共價鍵結，且該連接子係如式-R1-O(R2)m-Q-所示。此外，本發明進一步提供具有活性單元以共價鍵結的方式與該連接子結合的載體，其中，該活性單元為藥物、維生素或生物分子。
照護裝置
(2011-01-16)
蕭子健
;
林錫慶
;
林筱涵
;
趙志峰
本發明係提供一種照護裝置，其主要係利用訊號擷取模組感測人體的生理反應以產生訊號資料，接著，由具有運算判斷規則單元之處理模組將該訊號資料進行篩選與分析以降低該訊號資料之複雜度，並持續透過該運算判斷規則單元訓練及產生相應之特徵資訊，之後，再將該處理模組所產生之該特徵資訊傳送至照護平台，使照護平台能即時監視被照護者的狀態，並且可做為被照護者與他人溝通的重要背景資訊。藉此，透過本發明之照護裝置可過濾及消除非必要的資料或雜訊，並擷取對應該訊號資料之特徵資訊，俾有效縮減資料量。
角度量測陀螺儀系統及角度估算方法
(2011-01-16)
陳宗麟
;
紀建宇
一種角度量測陀螺儀系統，包含一包括一質量塊的陀螺儀、一感測模組，及一包括一狀態觀察器與一角度計算器的計算模組。該感測模組根據該質量塊的移動產生一組感測信號。該狀態觀察器根據一組估計參數計算一組估計信號，並得到一增益，且根據該陀螺儀的動態方程式、該增益、該組感測信號及該組估計信號更新該組估計參數。該組估計參數與包括該質量塊的位置與速度、該感測模組的感測誤差，及該陀螺儀的轉動角速度之一組系統參數對應。該角度計算器根據該組估計參數中對應位置與速度的參數，及該陀螺儀的剛性係數，計算該陀螺儀的轉動角度。
Constant voltage stress induced charge trapping and detrapping characteristics of the Si3N4 uniaxial strained n-channel metal-oxide-semiconductor field-effect-transistor with fluorinated HfO2/SiON gate stack
(2011-01-17)
Chen, Yung-Yu
;
Hsieh, Chih-Ren
;
Chiu, Fang-Yu
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Charge trapping and detrapping characteristics of Si3N4 contact etch stop layer (SiN CESL) uniaxial strained n-channel metal-oxide-semiconductor field-effect-transistor (nMOSFET) with fluorinated HfO2/SiON gate stack have been investigated for the first time. Smaller threshold voltage shift can consequently obtain for the SiN CESL strained nMOSFET with fluorinated HfO2/SiON gate stack, primarily due to passivation of oxygen vacancies and dangling bonds by either nitrogen or fluorine atoms. However, the SiN CESL strained nMOSFET with fluorinated gate stack inevitably exhibits less charge detrapping ratio, which means greater part of stress-induced charges would remain in the gate stack after nitrogen or fluorine incorporation, respectively. (c) 2011 American Institute of Physics. [doi:10.1063/1.3541878]
Constant voltage stress induced charge trapping and detrapping characteristics of the Si(3)N(4) uniaxial strained n-channel metal-oxide-semiconductor field-effect-transistor with fluorinated HfO(2)/SiON gate stack
(2011-01-17)
Chen, Yung-Yu
;
Hsieh, Chih-Ren
;
Chiu, Fang-Yu
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Charge trapping and detrapping characteristics of Si(3)N(4) contact etch stop layer (SiN CESL) uniaxial strained n-channel metal-oxide-semiconductor field-effect-transistor (nMOSFET) with fluorinated HfO(2)/SiON gate stack have been investigated for the first time. Smaller threshold voltage shift can consequently obtain for the SiN CESL strained nMOSFET with fluorinated HfO(2)/SiON gate stack, primarily due to passivation of oxygen vacancies and dangling bonds by either nitrogen or fluorine atoms. However, the SiN CESL strained nMOSFET with fluorinated gate stack inevitably exhibits less charge detrapping ratio, which means greater part of stress-induced charges would remain in the gate stack after nitrogen or fluorine incorporation, respectively. (c) 2011 American Institute of Physics. [doi:10.1063/1.3541878]