Browsing by Issue Date, starting with "2005-04-01"

Now showing 1 - 20 of 66957

Stable and tunable fiber double-ring laser based on an erbium-doped waveguide amplifier
(2005-04-01)
Chien, HC
;
Yeh, CH
;
Lee, CC
;
光電工程學系
;
Department of Photonics
A stable and tunable fiber double-ring laser based on an erbium-doped waveguide amplifier (EDWA) is proposed and experimentally demonstrated. A widely tunable range from 1527 to 1567 nm, the side-mode suppression ratio (SMSR) of > 45.6 dB/0.05 nm and the output power of > 1.04 dBm in the operating range from 1535 to 1565 nm can be achieved for this ring laser. By applying the double-ring configuration, the ring laser is stabilized. The central wavelength variation of < 0.02 nm and the power fluctuation of < 0.03 dBm can therefore be retrieved. (c) 2005 Society of Photo-Optical Instrumentation Engineers.
Manipulation of nanoneedle and nanosphere apatite/poly(acrylic acid) nanocomposites
(2005-04-01)
Liou, SC
;
Chen, SY
;
Liu, DM
;
材料科學與工程學系
;
Department of Materials Science and Engineering
Colloidal apatitic nanosphere of 2-5 nm in diameter was synthesized in the presence of poly(acrylic acid), PAA. PAA, which has long been recognized as an inhibitor in the synthesis of hydroxyapatite, is used as a structure-directing agent for the synthesis of calcium-deficient apatite (CDHA) in this study. Experimental observation suggests a critical amount of the low-molecular-weight PAA, above which morphological evolution of CDHA nanoparticles from needle to sphere was observed. This reveals that the PAA acts as an inhibitor for the growth of CDHA crystals. Further incorporation of PAA of high molecular weight formed a highly optically transparent nanocomposite, even with the nanospherical apatite loading up to 35 wt%, suggesting no agglomeration. This was further justified through transmission electron microscopy (TEM), where the CDHA nanospheres were uniformly distributed in the PAA-CDHA nanocomposites. No interfacial crevices were visually observed, indicating a highly compatible interface between the inorganic CDHA and organic PAA phase. (c) 2005 Wiley Periodicals, Inc.
Transition energies of vertically coupled multilayer nanoscale InAs/GaAs semiconductor quantum dots of different shapes
(2005-04-01)
Li, YM
;
奈米中心
;
Nano Facility Center
The energy spectra of vertically coupled multilayer nanoscale semiconductor quantum dots (QDs) are theoretically studied using a unified three-dimensional (3D) model. The model formulation includes (1) the position-dependent effective mass Hamiltonian in a nonparabolic approximation for electrons, (2) the position-dependent effective mass Hamiltonian in a parabolic approximation for holes, (3) the finite hard wall confinement potential, and (4) Ben Daniel-Duke boundary conditions. To solve a nonlinear problem, a nonlinear iterative method is further improved in our developed 3D QD simulator. At an applied magnetic field (B), we explore the transition energy and the energy band gap of disk (DI), ellipsoid (EL)- and cone (CO)-shaped vertically coupled multilayer nanoscale semiconductor quantum dots. We find that the electron transition energy of vertically coupled rnultilayer InAs/GaAs QDs depends on their shape and is strongly dominated by the number of stacked layers (N). The interdistance (d) among InAs QDs plays a crucial role in the tunable states of these QDs. In DI-shaped vertically coupled 10-layer QDs at B = 0T and d = 1.0nm, we find approximately 40% variation in electron ground state energy, which is larger than that (similar to 20% variation) in CO-shaped QDs. In QDs at a nonzero magnetic field, the electron transition energy decreases with increasing N. In QDs with d = 1nm, the rate of decrease is low when N > 6. This results in QDs,with energy band gaps having similar dependences on N. This study implies different applications in magnetooptical phenomena and quantum optical structures.
Effective approaches for low temperature polysilicon TFT LCD post-mapping yield control problem
(2005-04-01)
Su, CT
;
Wang, PS
;
Hsu, CC
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Low-temperature polysilicon (LTPS) technology has drawn the attention of many display manufacturers because it has several potential advantages over amorphous thin-film-transistor liquid crystal display (TFT LCD). The mapping operation matches one TFT and one color-filter (CF) glass plate together to form one LCD plate. Each plate contains a certain number of cells that are independent devices. The matched LCD cell is good only when the TFT and CF cell match is good. When only a TFT or CF cell is good, there is a yield loss. The sorter is a robot used in LCD manufacturing systems to achieve higher yield in matching TFT and CF plates. This sorter contains several ports that can transfer CF glasses from CF cassettes to match TFT glasses. This is an important determinant for post-mapping yield. This study first proposes a linear programming formulation to optimize the plates-matching problem for the various ports. Next, we propose an algorithm to reduce the number of ways for choosing different matched objects when the number of matched cassettes is large. This algorithm avoids computer overload and provides an excellent solution. The empirical results illustrate the efficiency and effectiveness of the proposed approaches.
Comment on "discrete-time optimal fuzzy controller design: Global concept approach" - Reply
(2005-04-01)
Wu, SJ
;
Lin, CT
;
電控工程研究所
;
Institute of Electrical and Control Engineering
Characteristics of the inter-poly Al2O3 dielectrics on NH3-nitrided bottom poly-si for next-generation flash memories
(2005-04-01)
Chen, YY
;
Chien, CH
;
Lou, JC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The effects of surface NH3 nitridation of the bottom poly-Si film, and post-deposition annealing (PDA) temperature, on the electrical properties and reliability characteristics of aluminum oxide (Al2O3) inter-poly capacitors, were evaluated in this study. The polarity-dependent dielectric properties of Al2O3 inter-poly dielectrics (IPDs) were strongly affected by both surface nitridation and the annealing temperature. For positive gate bias, IPDs with NH3 surface nitridation significantly suppressed the formation of an additional layer with a lower dielectric constant, during the post-annealing process, and obtained a smoother interface, compared to those without nitridation treatment. Furthermore, the presence of a thin Si-N layer made the PDA more effective in eliminating the traps existing in the as-deposited films, and improved dielectric characteristics, under negative polarity. As a result, the smoother interface and smaller electron trapping rate contributed to the drastically reduced leakage current, enhanced breakdown field, and charge to breakdown (Q(bd)) of the Al2O3 inter-poly capacitors with surface NH3 nitridation. Moreover, the electrical properties of Al2O3 IPD were heavily dependent upon the PDA temperature. The sample exhibited optimal quality in terms of leakage current, electron trapping rate and Qbd when annealed at 900 degrees C. X-ray photoelectron spectroscopy and Auger electron spectroscopy analyses have shown that this occurrence arises from various compositions, under different annealing conditions and excess oxygen, which can act as an electron trapping center, playing an important role in determining IPD electrical properties.
Characterization of InGaN/GaN multiple quantum well nanorods fabricated by plasma etching with self-assembled nickel metal nanomasks
(2005-04-01)
Hsueh, TH
;
Huang, HW
;
Kao, CC
;
Chang, YH
;
Ou-Yang, MC
High-density (3.0 x 1010 cm (-2)) InGaN/GaN Multiple quantum well (MQW) nanorods were fabricated from an as-grown bulk light-emitting diode structure by inductively coupled plasma dry etching with self-assembled nickel metal nanomasks. The self-assembled nickel metal nanomasks were formed by rapid thermal annealing of a nickel metal film at 850 degrees C for 1 min. The influence of the thicknesses of the Ni metal film on the dimensions and density of the nanorods was also investigated. The structural and optical properties of the InGaN/GaN MQW nanorods were established using field emission scanning electron microscopy, transmission electron microscopy and photoluminescence measurements. The diameters and heights of nanorods were estimated to be 60 to 100nm and more than 0.28 mu m, respectively. The peak emission wavelength of the nanorods showed a blue shift of 5.1 nm from that of the as-grown bulk. An enhancement by a factor of 5 in photoluminescence intensity of the nanorods compared with that of the as-grown bulk was observed. The blue shift is attributed to strain relaxation in the wells after dry etching, the quantum confinement effect, or a combination of the two, which results in the enhancement of emission intensity.
Modeling geometry-dependent floating-body effect using body-source built-in potential lowering for SOI circuit simulation
(2005-04-01)
Su, P
;
Lee, W
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper presents a compact silicon-on-insulator (SOI) model to capture the geometry-dependent floating-body effect using the body-source built-in potential lowering approach. This physically accurate model circumvents the modeling challenge imposed by the trend of the coexistence of partial-depletion (PD) and full-depletion (FD) devices in a single SOI chip by considering short-channel, reverse short-channel and reverse narrow-width floating-body effects. The implication on circuit simulation, under the unified Berkeley short-channel IGFET model-silicon-on-insulator (BSIMSOI) framework, has also been addressed. This geometry-dependent body-source built-in potential lowering model will further enhance the device design of scaled SOI complementary metal-oxide-semiconductor (CMOS) below 100 nm.
A new method for fuzzy information retrieval based on fuzzy hierarchical clustering and fuzzy inference techniques
(2005-04-01)
Horng, YJ
;
Chen, SM
;
Chang, YC
;
Lee, CH
;
資訊工程學系
In this paper, we extend the work of Kraft et al to present a new method for fuzzy information retrieval based on fuzzy hierarchical clustering and fuzzy inference techniques. First, we present a fuzzy agglomerative hierarchical clustering algorithm for clustering documents and to get the document cluster centers of document clusters. Then, we present a method to construct fuzzy logic rules based on the document clusters and their document cluster centers. Finally, we apply the constructed fuzzy logic rules to modify the user's query for query expansion and to guide the information retrieval system to retrieve documents relevant to the user's request. The fuzzy logic rules can represent three kinds of fuzzy relationships (i.e., fuzzy positive association relationship, fuzzy specialization relationship and fuzzy generalization relationship) between index terms. The proposed fuzzy information retrieval method is more flexible and more intelligent than the existing methods due to the fact that it can expand users' queries for fuzzy information retrieval in a more effective manner.
Surface excitation parameter for semiconducting III-V compounds
(2005-04-01)
Kwei, CM
;
Tu, YH
;
Tung, CJ
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In the rapid development of mesoscopic science, the study of surface excitations in solids and overlayer systems plays a crucial role. The surface excitation parameter which describes the total probability of surface plasmon excitations by an electron traveling in vacuum before impinging on or after escaping from a semiconducting III-V compound has been calculated for 200-2000 eV electrons crossing the compound surface. These calculations were performed using the dielectric response theory with sum-rule -constrained extended Drude dielectric functions established by the fits of these functions to optical data. Surface excitation parameters calculated for InSb, InAs, Gap, GaSb or GaAs III-V compounds were found to follow to a simple formula, i.e. P-s = aE(-b), where Ps is the surface excitation parameter and E is the electron energy. These surface excitation parameters were then applied to determine the elastic reflection coefficient for electrons elastically backscattered from III-V compounds using the Monte Carlo simulations. Good agreement was found for the electron elastic reflection coefficient between calculated results and experimental data. (c) 2004 Elsevier B.V. All rights reserved.
Low temperature synthesized Sn doped indium oxide nanowires
(2005-04-01)
Li, SY
;
Lee, CY
;
Lin, P
;
Tseng, TY
;
材料科學與工程學系
Selective, well controlled and directionally grown Sri doped In2O3 nanowires (In2O3: Sn nanowires, SIO NWs) were synthesized at a low fabrication temperature (&SIM; 770&DEG; C) through a vapour-liquid-solid (VLS) process under a precise carrier gas flow. The majority of the SIO NWs are grown along [222], with [400] and [440] as minority forming directions, which implies a nearly epitaxial crystal structure. There are fewer physical defects, such as line or planar defects and contaminations, in the SIO NWs than in pure In2O3 nanowires seen through high resolution transmission electron microscopy (HR-TEM) observations. The spectrum of photoluminescence (PL) emission indicates a stable strong blue light peak located at &SIM; 440 nm with an excited wavelength of 275 nm at room temperature. The Sri dopant in the SIO NWs can enhance the conductivity of the nanowires leading to the lowering of the turn-on electric-field to 0.66 V μ m(-1) under a current density of up to 1.0 mA cm(-2) based on their field emission characteristics. Furthermore, the field emission enhancement coefficient, β, is also increased to 1.48 x 10(5), which is very close to the carbon nanotube, (CNT) level. SIO NWs fabricated by a VLS process offer a potential application in flat panel displays as demonstrated in this study.
A novel PHINES flash memory cell with low power program/erase, small pitch, two-bits-per-cell for data storage applications
(2005-04-01)
Yeh, CC
;
Wang, TH
;
Tsai, WJ
;
Lu, TC
;
Chen, MS
A novel programming by hot-hole injection nitride electron storage (PHINES) Flash memory technology is-developed. The memory bit size of 0.046 mu m(2) is fabricated based on 0.13-mu m technology. PHINES cell uses a nitride trapping storage cell structure. Fowler-Nordheim (FN) injection is performed to raise V-t in erase while programming is done by lowering a local V-t through hand-to-hand tunneling-induced hot hole (BTBT HH) injection. Two-bits-per-cell feasibility, low-power and high-speed program/erase, good endurance and data retentivity make it a promising candidate for Flash EEPROM technology in gigabit era applications.
Hemocompatibility and anaphylatoxin formation of protein-immobilizing polyacrylonitrile hemodialysis membrane
(2005-04-01)
Liu, TY
;
Lin, WC
;
Huang, LY
;
Chen, SY
;
Yang, MC
Plasma proteins were covalently immobilized onto polyacrylonitrile (PAN) membrane to evaluate the hemocompatibility and anaphylatoxin formation. This is used as a model to study the effect of protein-adsorption on the blood-contacting response of hemodializing membranes. The proteins used were either platelet-adhesion-promoting collagen (COL) or platelet-adhesion-inhibiting human serum albumin (HSA). The microstructure and characterization of the protein-immobilizing PAN membranes were evaluated by Coomassie dye assay, atomic force microscopy, X-ray photoelectron spectroscopy and water contact angle measurement. PAN-HSA membrane improved not only hemocompatibility including less platelet adhesion, longer blood coagulation times, and higher thrombin inactivity level, but also induced lower complement activation. On the other hand, PAN COL membrane exhibited blood incompatibility, although induced less increase of C3, C4 antigens of serum. Overall results of this study demonstrated that the immobilization of HSA onto the surface of PAN membrane would be beneficial to improve the hemocompatibility and to reduce the anaphylatoxin formation during hemodialysis. (C) 2004 Elsevier Ltd. All rights reserved.
Mobility enhancement in local strain channel nMOSFETs by stacked a-Si/poly-Si gate and capping nitride
(2005-04-01)
Lu, TY
;
Chao, TS
;
交大名義發表
;
National Chiao Tung University
A local strained channel nMOSFET has been fabricated by a stress control technique utilizing a stacked a-Si/poly-Si gate and a SiN capping layer. It is found that the transconductance (G(M)) of nMOSFETs increases as the thickness of a-Si is increased. We also found that the G(M) of devices with the SiN capping layer exhibits a 17% increase compared to that of its counterparts. The stacked gate a-Si/poly-Si with the capping layer can improve the G(M) further to 29% more than the single-poly-Si gate structure without SiN capping layer.
Improvement in instable analysis of heat inflation induced line-width after replacing pellicle with diamond film on reticle (photo-masks)
(2005-04-01)
Kuo, YK
;
Chao, CG
;
材料科學與工程學系
;
Department of Materials Science and Engineering
A new reticle is designed that takes advantage of the high value of thermal conductivity of diamond to add a layer of diamond film to the bottom of traditional pellicle-reticle; that is, the new reticle replaces the pellicle with a diamond material. This method may help maintain the future manufacturing process of photo-lithography below 35 nm and can improve the problem of slightly out of shape reticle caused by the long-term effects of light and thermal energy. (c) 2004 Elsevier B.V. All rights reserved.
垂直入射型折射率測量裝置
(2005-04-01)
蘇德欽
;
許正治
;
陳坤煌
本發明係揭露一種垂直入射型折射率測量裝置，其係將由左旋偏光及右旋偏光間有頻差的旋光外差光源所發出來的光線，經一偏光保持光纖將光入射於一測試模組。一檢偏板抽出經高反射面鏡及待測物垂直反射而回光束中相同的偏極光成份，並使之干涉；其干涉信號由光偵測器測得。再利用一相位計分析光偵測器所得的訊號可得到經由待測物所引進的相位差，此相位差與待測物的折射率有關；最後再根據瓊斯計算法(Jones calculus)與斯涅耳方程式所推演出的公式以及由外差干涉術所測出的相位差變化，便可計算出待測物的折射率。由於本發明無須使用造成全反射的稜鏡，所以對於待測物的量測範圍將不會受探頭折射率的限制，故量測範圍較為廣泛並以垂直入射待測物，所以裝置及操作上都更為簡單。
吾爹身上有兩顆子彈，一顆made in日本，一顆made in解放軍
(2005-04-01)
管管
自我管理團隊目標互賴性、團隊成員互動過程對團隊信任影響之研究
(2005-04-01)
廖國鋒
;
費吳琛
;
丁文養
;
Gou-Fong Liaw
;
Wu-Chen Fei
近年來管理者已意識到目前組織內工作兼具複雜性與分工協調性的特色，實無法靠個人的力量獨立完成；唯有依員工組成團隊，集合團隊中每個人的能力與特色，發揮團隊力量協力完成。今天由各種具技能的隊員組成的工作團隊，已取代傳統的運作模式，走向扁平化發展，而在組織扁平化下如何激發團隊最大潛力成為最重要課題。本研究引入Deutsch於1949，1973，1980，1990年所提出之合作、競爭理論，定義了三種解釋團隊目標互賴性的方式，藉以探討團隊目標如何透過團隊運作過程，進而影響團隊信任。經取樣生產製造、客戶服務等單位團隊成員進行實證研究，其結果顯示出：當團隊成員相信目標為合作時，會營造良好的溝通、爭論情境，有效管理衝突，進而產生團隊成員間互相的信任。相對的，競爭的目標會阻擾溝通、爭論，進而影響成員間的信任，妨礙團隊績效之達成。所以，建構合作性的目標能幫助團隊成員獲得彼此間的信任，並使團隊工作更有效率。
Distribution and susceptibility to amphotericin B and fluconazole of Candida spp. isolated from Taiwan
(2005-04-01)
Yang, YL
;
Ho, YA
;
Cheng, HH
;
Lo, HJ
;
生物科技學系
Susceptibilities to amphotericin B and fluconazole of 628 clinical yeast strains collected from 22 hospitals in Taiwan were determined. A total of 53 isolates (8.4%) were resistant to fluconazole. Each hospital had different resistance rate to fluconazole ranging from 0 % to 24 %. None of the 186 isolates from eight of the 22 hospitals was resistant to fluconazole. In contrast, isolates from nine of the remaining 14 hospitals had greater than 10 % resistance rate to fluconazole. Consistently, 88.9 % (8/9) fluconazole-resistant C. albicans isolates were from hospitals having a high resistance rate to fluconazole. The prevalence of various Candida spp. in each hospital was different. A positive association was found between the prevalence of C. tropicalis and the resistance rate to fluconazole for individual hospitals. Although only three isolates (0.5 %) were resistant to amphotericin B, a co-resistance to both amphotericin B and fluconazole was observed, which highlights the emerging problem of drug resistance.
A new conceptual framework integrating environment into corporate performance evaluation
(2005-04-01)
Sheu, HJ
;
Lo, SF
;
交大名義發表
;
National Chiao Tung University
Businesses aim to make profit, but very often they fail to take environmental protection into consideration in the drive to please stakeholders. In this article, a new conceptual framework for evaluating corporate integrated development through the perspective of efficiency (looking at the company's work value created in terms of input-output) is introduced. Under the proposed framework, businesses, investors and society can conveniently understand and evaluate corporate holistic performance including its operational competence, financial health and environmental friendliness. Therefore, decisions of different levels and groups could be made with programmed consideration on this purely analytical ground. Copyright (c) 2005 John Wiley & Sons, Ltd and ERP Environment.