Browsing by Issue Date, starting with "2009"

Now showing 1 - 20 of 53780

Low-Concentration 1,2-trans beta-Selective Glycosylation Strategy and Its Applications in Oligosaccharide Synthesis
(2009)
Chao, Chin-Sheng
;
Li, Chen-Wei
;
Chen, Min-Chun
;
Chang, Shih-Sheng
;
Mong, Kwok-Kong Tony
This study develops an operationally easy, efficient, and general 1,2-trans beta-selective glycosylation reaction that proceeds in the absence of a C2 acyl function. This process employs chemically stable thioglycosyl donors and low substrate concentrations to achieve excellent beta-selectivities in glycosylation reactions. This method is widely applicable to a range of glycosylsubstrates irrespective of their structures and hydroxyl-protecting functions. This low-concentration 1,2-trans beta-selective glycosylation in carbohydrate chemistry removes the restriction of using highly reactive thioglycosides to construct 1,2-trans beta-glycosidic bonds. This is beneficial to the design of new strategies for oligosaccharide synthesis, as illustrated in the preparation of the biologically relevant beta-(1 -> 6)-glucan trisaccharide, beta-linked Gb(3) and isoGb(3) derivatives.
Cross-national and cross-industrial comparison of two strategy approaches for global industrial evolution
(2009-01-01)
Yang, Chia-Han
;
Shyu, Joseph Z.
;
科技管理研究所
;
Institute of Management of Technology
This research focuses on analyzing the two prime science and technology (S&T) strategy approaches for industrial evolution based on the concept of S&T gap, namely, the optimist and pragmatist approaches. Particularly. the cases of global IC, pharmaceutical, and computer industries, are used to make cross-national and cross-industrial comparison of these two approaches. The optimist approach is developed based on the product life cycle theory which envisions technology transcending everyday limitations. With this perspective, market demand is the most critical factor in selecting the S&T strategy approaches. The pragmatist approach is formed based on the new trade theory which recognizes the power of science and technology but seeks to fit it into structures that already exist, and government must manage resources pouring into science and technology. Case studies of global IC, pharmaceutical, and computer industries during the 2nd half of the 20th century are used as research targets to reflect policy impacts on the technological evolution. The results of this study reveal that, strategy approaches have to be adapted and turned to the specific stage, technology level, and market segment that have been selected for intervention. This result of comparison also offers the criteria of strategy selection for developing different industry based on distinct national base. (C) 2008 Elsevier Inc. All rights reserved.
智慧型生物訊號誘導藥物釋放系統前瞻研究:以癲癇症為模式---應用於訊號誘導藥物釋放系統之智慧型生醫複合材料結構製程與性質研究(總計畫及子計畫二)(III)
(2009)
陳三元
;
CHEN San-Yuan
;
國立交通大學材料科學與工程學系(所)
Electronic Structure and Magnetic Anisotropies in Orthorhombic Multiferroic YMnO3 Thin Films
(2009-01-01)
Hsieh, C. C.
;
Lin, T. H.
;
Shih, H. C.
;
Lin, J-Y
;
Hsu, C-H
Thermodynamically YMnO3 (YMO) can only exist with hexagonal structure at ambient conditions. In this study, we demonstrate that the stain between film and substrate can play an important role in forming orthorhombic YMO (o-YMO). o-YMO films with nearly perfect crystallographic orientation alignment were obtained on LaAlO3(110) substrates. These films allow us to unambiguously disclose the intrinsic magnetic property and electronic structure anisotropies along different crystallographic orientations. The antiferromagnetic (AFM) phase transition was around 42 K. Moreover, we observed a signature of spin reordering at lower temperatures when the applied field was parallel to the a- or c-axis. On the other hand, only the AFM transition was observed when the field is parallel to the b-axis. By comparing the X-ray absorption spectroscopy (XAS) results to standard manganese oxides, YMnO3 exhibits the dominant Mn+3 characteristics as that obtained from the standard Mn2O3 powder. The polarization dependent XAS also revealed anisotropic bonding behavior along each crystalline axis.
Ultrafast dynamics in oxygen-deficient Y(0.7)Ca(0.3)Ba(2)Cu(3)O(7-delta) superconductors
(2009)
Luo, C. W.
;
Huang, T. C.
;
Wu, K. H.
;
Juang, J. Y.
;
Lin, J-Y
The transient reflectivity change (Delta R/R) in oxygen-deficient Y(0.7)Ca(0.3)Ba(2)Cu(3)O(7-delta) (YCaBCO) thin films have been systematically measured at various temperatures by femtosecond spectroscopy. The magnitude change of Delta R/R from normal state to superconducting state were clearly observed in YCaBCO with various oxygen deficient, e.g. from overdoped region over optimaldoped region to underdoped region. Additionally, the carrier-phonon coupling strength was also characterized by the relaxation time of Delta R/R at various temperatures and hole concentration.
Multicast Network with MMI-based Optical Switches on Active Splitter/Active Combiner Structure
(2009)
Lee, Chi-Ping
;
Deng, Jiun-Shiou
;
Lu, Ming-Feng
;
Chang, Chien-Ping
;
Huang, Yang-Tung
Multicast communications have become more and more important recently, especially in their applications in multimedia communication, quality of service (QoS), video conferencing, and distance education. In a point-to-point (PTP) optical communication system, how to provide multicast services is an essential issue. There are some advantages of active splitter/active combiner (AS/AC) networks, such as strictly nonblocking, simpler routing algorithm, lower system-insertion-loss, zero differential loss, and better signal-to-noise characteristics. The active multimode interference (MM!) coupler can provide splitting/combining operations with low loss and good balancing. It has been demonstrated that the AS/AC network constructed by active MMI switching devices can implement the multicast and PTP communications simultaneously. In this study, we offer two multicast algorithms, parallel multicast, and tunable multicast, on AS/AC network. The parallel multicast algorithm is suitable when there are multi requests arriving at the same tame. The tunable multicast algorithm is suitable for balancing the output signals\' power.
Friction Compensation of a Mini Voice Coil Motor by Sliding Mode Control
(2009)
Tsai, Ching-Lung
;
Lee, Ti-Chung
;
Lin, Shir-Kuan
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper presents a sliding mode controller to compensate the friction of mini voice-coil motor (VCM), embedded with guide pins, for position control in compact camera module (CCM) application. In the VCM, actuator full stroke is only 0.35mm or less, nonlinear friction force falls into mismatched condition and um-level resolution is required. With proposed controller, arbitrarily small steady state error can be approached by pole placement tithe sliding mode state equation. The performance is firstly simulated with a physical VCM model. The experimental result is then presented to demonstrate the proposed controller is able to avoid stick-slip oscillation that usually yields when using classic controller, such as PI controller.
具生物反饋機制之智慧型長時睡眠監測系統---子計畫一：應用於智慧型長時睡眠監測系統之感測器與類比前端積體電路設計(I)
(2009)
林俐如
;
Lin Li-Ju
;
國立交通大學電子工程學系及電子研究所
市面上生理訊號量測系統不但昂貴而且體積龐大，對於睡眠障礙患者或嬰兒等需要使用長時睡眠監控系統的人來說，過多的纜線與過大的機器也造成使用上的不便，妨礙睡眠。解析睡眠當中進行的多重生理監測，包含腦電圖、心電圖、肌電圖與眼電圖，其前端訊號均為類比的電訊號，大小差距僅有五十倍，頻寬分佈也僅相差不到五倍，皆為非侵入體表量測方式，若將這些生理訊號用同一組放大電路讀出，並搭配數位與類比的SOC整合晶片，將可大幅縮小監測系統的體積。本計畫並採用新型乾式電極作為前端感測器，並將放大器電路與電極整合變成主動式電極，整個系統的放大器將與電極一起分散在不同的量測點，經由導線將訊號傳輸至處理器端，透過類比多功器與類比數位轉換器將不同的生理訊號轉換為數位訊號，進行後續資料探勘與儲存動作。此設計不但能大幅提高訊號雜訊比，並且能自由調配不同生理訊號的通道數，成為通用生理訊號放大器。本計畫並研發新型之光聲感測器作為血氧濃度偵測器，藉由發射紅外線脈衝，能使血紅素吸收光波膨脹並收縮，放出超音波，而藉此超音波訊息能判斷血氧濃度，瞭解睡眠狀況與血氧濃度的關係。而本計畫中的類比數位轉換器，與其他子計畫的數位電路透過SOC整合後，能達到微型化可攜式智慧型長時睡眠監控系統，能協助臨床上更精確的睡眠障礙診斷，並能有效預防嬰兒猝死的不幸事件。
高效率高分子太陽電池---分子設計合成、奈米結構控制及元件工程
(2009)
許千樹
;
HSU CHAIN-SHU
;
國立交通大學應用化學系（所）
建構同時自營異營脫硝系統
(2009)
林志高
;
LIN JIH-GAW
;
國立交通大學環境工程研究所
正特徵域上丟番圖逼近的賦距結果
(2009)
符麥克
;
FUCHS MICHAEL
;
國立交通大學應用數學系(所)
摘要：近來的研究文獻，H. Nakada and R. Natsui 在正規Laurent 級數域上考慮─ 沒有互質條件下的丟番圖逼近(Diophantine approximation)，得到其解的個數滿足強大數法則。利用早先W. M. Schmidt 所提出的方法，他們的結果是非常可能有相當程度地增進。在這個計畫中，我們將在非齊次丟番圖逼近、有限丟番圖逼近及同時丟番圖逼近，研究類似的問題，並發展出較增進的結果。
Efficiency Optimization Control for Single-Phase Brushless DC Fan Motors
(2009)
Chen, Wei-Chao
;
Tzou, Ying-Yu
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper proposes a modeling method for characterization of single-phase brushless dc (BLOC) fan motors in applications to information appliances. The nonlinear back-EMF induced by the rotor flux with stator winding is modeled by a look-up table. By parameter identification and computer simulation, this modeling method assists designers in waveform analysis and control loop design. Simulation results have been verified with the measured experimental results. Moreover, in order to improve the efficiency of the BLDC fan motor over the entire speed control range, this paper develops an efficiency optimization control method based on a closed-loop current control scheme by using the Hall sensor feedback. The proposed control scheme has been realized and compared with the conventional open-loop PWM control scheme. Experimental results show a 40% reduction of peak current and 18% reduction of RIMS current have been achieved at rotation speed of 3000 RPM.
ZigBee無線樹狀感測網路之初始化及通訊問題研究
(2009)
曾煜棋
;
TSENG YU-CHEE
;
國立交通大學資訊工程學系(所)
無線感測網路相關的研究議題得到許多研究單位及學者的關注，近年來ZigBee 通訊協定被視為最適用於感測網路的通訊協定，本計畫將研究以ZigBee 樹狀網路為基礎之無線感測網路相關通訊協定，本計畫目標主要包含三個面向：(1) ZigBee 無線感測網路生成之研究，(2) ZigBee 樹狀網路資料傳遞排程，(3) ZigBee 基礎之長鏈狀網路研究。在第一個研究主題中，我們研究ZigBee 感測網路的生成問題，在ZigBee 規範中，一個節點加入到一個網路的條件為：該節點能找到一個父節點能夠給予該節點一ZigBee 網路位址，父節點們可利用ZigBee 所定義之分散式位址分配法來指定位址給子節點們，這一個位址指定方法相當簡單但是卻限制了一個節點最多可容忍之子節點個數以及整體網路的深度，我們觀察到如果使用ZigBee 所定義之網路生成方式，會使得網路位址的使用率偏低，進而造成節點無法連上網路，因此在本計畫中，我們提出適用於ZigBe 之網路生成方法，我們的目標是為能夠使得網路上的節點能夠自動組態並且形成一個可通訊之網路。在第二個研究主題中，我們研究ZigBee 樹狀網路封包排程，在許多無線感測網路的應用中，網路上的節點被要求回報資料給一個資料收集伺服器，早先所提出之資料回報流排程方式皆著重於要節省網路節點電量消耗與降低回報延遲，但是該些方法皆不能適用於ZigBee 網路。在考量ZigBee 的特性下，本計畫將探討該如何排程節點的信標訊框，並將提出信標排程演算法，目標為針對資料流之特性來排定網路節點之運作時間，以達到省電之目的。除了考量回報性的資料流外，我們亦會討論廣播性的資料流之封包排程。在第三個研究主題中，我們探討一特殊網路—長鏈狀網路，在這一網路中節點們被部署為數個長條狀拓樸，這些長條狀拓樸們連接成一個網路，並且覆蓋整個想要涵蓋之範圍，這一網路看似為一個特例型態網路，但是我們觀察到該網路型態是相當常見於許多無線感測網路之應用中。本計畫探討該如何將ZigBee 協定用於此一特殊但卻常見之樹狀拓樸中。我們預計將從網路層協定來切入討論，我們發現原有ZigBee 定義之位址指定方式與路由方式並不適用於此長鏈狀網路，因此我們的目標為提出簡單又有效之適用於長鏈狀網路之位址指派方法以及路由通訊協定。上述三個研究方向除了理論方面的探討外，本計畫實做出所設計之演算法，並且探討理論與實務經驗上之差別，我們期許本計畫能夠理論與實務兼顧，並且為ZigBee 樹狀網路尖端研究。
國立交通大學傳播與科技學系陶振超教師升等送審著作論文集
(國立交通大學, 2009)
陶振超
比較廣告不同類別對衝突性利益與競爭效能關聯的干擾角色
(2009-01-01)
施錦村
;
Chin-Tsun Shih
;
Institute of Business and Management
;
經營管理研究所
本研究從競爭市場構面驗證比較廣告衝突性利益與競爭效能的關聯，及比較廣告不同類別對競爭效能的干擾效果，有别於過去大部分文獻均從個別品牌探討比較廣告強度對廣告效果的影響，同時也填補了該領域的研究缺口。本研究樣本資料來自台灣公平會1992年至2007年的實際案例，該等資料經由內容分析法、SEM及區別分析等統計分析工具驗證，實證結果可分成二部分：其一，衝突性利益與競爭效能的關聯除廣告負面效果與競爭效能間之反向關係，未獲實證支持外，其餘2項假設（正面效果與競爭效能間之正向關係；正（反）面效果間反向關係）均獲得實證支持；其二，間接比較廣告之競競爭效能優於直接比較廣告。以上實證結果，除與現有理論文獻大致相符外，在實務運用上，對廣告主完成有競爭效能的比較廣告及台灣競爭法主管機關在實務運作上，均具有參考價值。
生物系統內分子交互作用及生化路徑之大規模分析---(總計畫與子計畫一)以生化網路演化關係研究分子交互作用與生化路徑(II)
(2009)
楊進木
;
YANG JINN-MOON
;
國立交通大學生物科技學系(所)
In-situ TEM Study of Electromigration in Cu lines
(2009)
Liao, C. N.
;
Chen, K. C.
;
Wu, W. W.
;
Chen, L. J.
;
Tu, K. N.
The density of electric current passing through interconnecting wires in integrated circuits (IC) is increasing with continuous miniaturization of IC. Under a high operating temperature and large electric current density, some voids and hillocks may form in the interconnecting wires due to electromigration (EM), leading to device failures eventually. In this study atomic-scale EM in unpassivated copper lines has been investigated in ultrahigh vacuum by in situ transmission electron microscopy (TEM). The EM-induced atomic surface diffusion was found to be crystal-orientation dependent and occurred preferentially on the {111} planes along < 110 > directions. The high-resolution TEM images and the electron diffraction patterns of a (111)-oriented Cu grain in the Cu line revealed an EM-induced step structure at surface. Moreover, the triple point where a twin boundary meets a grain boundary was found to slow down atomic EM at grain boundaries because of the incubation time of nucleation of a new step at the triple point. The long incubation time slows down the overall rate of atomic transport. The results suggest that the EM reliability of Cu interconnects may be enhanced by forming a high density of nanometer scaled twins in the coarse-grain Cu wires.
A Charge-Reservoir with Buck-Store and Boost-Restore (BSBR) Technique for High Efficient Conversion and Low Cost Solution of RGB LED Display Panels
(2009)
Hsieh, Chun-Yu
;
Yang, Chih-Yu
;
Huang, Ming-Hsin
;
Li, Don-Hwan
;
Chen, Chi-Lin
A boost converter with buck-store and boost-restore (BSBR) technique fabricated by 0.25 mu m CMOS BCD process can provide different supply voltages to drive series RGB LEDs in sequence for reducing the power consumption on the constant current generator. The proposed technique not only stores and restores extra charge during the transient time of the reference tracking response to improve the efficiency but also enhances the reference tracking response to greatly reduce load transition time. Experimental results show that the period of reference-tracking response can be improved. When the load current is 100mA, the periods of reference down-tracking and up-tracking are smaller than lops and 20 mu s, respectively. Furthermore, this technique also can provide a regulated voltage to drive the sub-block implemented in the LCD system. The maximum efficiency of charge recycling is up to 94% and the maximum efficiency of this boost converter is 92.5%. Experimental results demonstrate fast and efficient reference tracking performance is achieved by the proposed BSBR technique.
Pricing display ads and contextual ads: Competition, acquisition, and investment
(2009-01-01)
Li, Yung-Ming
;
Jhang-Li, Jhih-Hua
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
Most websites are simultaneously supported by display advertising and contextual advertising. In this paper, we develop an economic model to examine the profitability of these two ad types in both a monopolistic market and duopolistic market, identifying the influence of impression benefit and click benefit. We find that in the duopolistic market a rival channel's professional ability to enhance a visitor's impression is beneficial to the channel offering contextual advertising. We also find that the strength of a search engine is limited in the duopolistic market; therefore, acquisition becomes a prime strategy to reveal the value of contextual advertising. (c) 2008 Elsevier B.V. All rights reserved.
Privacy Protection and Authentication for Medical Images with Record-Based Watermarking
(2009)
Huang, Hsiang-Cheh
;
Fang, Wai-Chi
;
Chen, Shin-Chang
;
交大名義發表
;
National Chiao Tung University
In this paper, we propose a practical scheme for privacy protection and authentication of medical images with the aid of EXIF metadata and associated records of the patients. By using watermarking, the goals mentioned above can be reached. Application for robust watermarking is one of the major branches in digital rights management (DRM) systems. With robust watermarking, it generally alters selected coefficients in the transform domain to accomplish the embedding process. We consider not only the image contents itself, but we also employ the EXIF metadata, which contains the patients\' records and serves as the role of watermark, to be integrated into our scheme. By doing so, the false negative probability for obtaining the record can be reduced. Moreover, taking the information that the medical doctor recorded in the EXIF metadata into account, conventional watermarking techniques can be applied to medical images, and watermarked images with good quality can be produced. Even when the marked image has been intentionally modified, the original EXIF with selected information can mostly be recovered from the decoding process. Simulation results present the effectiveness of such an implementation.