Browsing by Issue Date, starting with "2005-06-23"

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[DOUBLE-TRIGGERED SILICON CONTROLLING RECTIFIER AND ELECTROSTATIC DISCHARGE PROTECTION CIRCUIT THEREOF]
(2005-06-23)
Ker, Ming-Dou
;
Hsu, Kuo-Chun
A double-triggered silicon controller rectifier (SCR) comprises a plurality of N+ diffusion areas, a plurality of P+ diffusion areas, a first N-well region, a second N-well region and a third N-well region formed in a P-substrate. The N+ diffusion areas and the P+ diffusion areas are isolated by shallow trench isolation (STI) structures. Two of the N+ diffusion areas are N-type trigger terminals. Two of the P+ diffusion areas are the P-type trigger terminal.
Comment on "Formation of repetitively nanosecond spatial solitons in a saturable absorber Q-switched laser" - Reply
(2005-06-24)
Chen, YF
;
Huang, KF
;
電子物理學系
;
Department of Electrophysics
EXTRACTION OF CORONARY ARTERIAL TREE USING CINE X-RAY ANGIOGRAMS
(2005-06-25)
Lin, Chih-Yang
;
Ching, Yu-Tai
;
資訊工程學系
;
Department of Computer Science
An efficient and robust method for identification of coronary arteries and evaluation of the severity of the stenosis on the routine X-ray angiograms is proposed. It is a challenging process to accurately identify coronary artery due to poor signal-to-noise ratio, vessel overlap, and superimposition with various anatomical structures such as ribs, spine, or heart chambers. The proposed method consists of two major stages: (a) signal-based image segmentation and (b) vessel feature extraction. The 3D Fourier and 3D Wavelet transforms are first employed to reduce the background and noisy structures in the images. Afterwards, a set of matched filters was applied to enhance the coronary arteries in the images. At the end, clustering analysis, histogram technique, and size filtering were utilized to obtain a binary image that consists of the final segmented coronary arterial tree. To extract vessel features in terms of vessel centerline and diameter, a gradient vector-flow based snake algorithm is applied to determine the medial axis of a vessel followed by the calculations of vessel boundaries and width associated with the detected medial axis.
吃茶圖卷
(2005-06-28)
管管
Using a solution crystal growth method to grow arrays of aligned, individually distinct, single-crystalline TiO2 nanoneedles within nanocavities
(2005-06-28)
Weng, CC
;
Chen, CP
;
Ting, CH
;
Wei, KH
;
材料科學與工程學系
Preparation and properties of polyacrylate/clay photocured nanocomposite materials
(2005-06-28)
Wang, YY
;
Hsieh, TE
;
材料科學與工程學系
;
Department of Materials Science and Engineering
A functionalized surfactant, GME-N-C-10 containing a C=C double bond, was synthesized to modify clays such as montmorillonite (MMT) and mica for the preparation of organic-inorganic composite resins via radical photoinduced polymerization. As revealed by X-ray diffraction (XRD) analysis of the organophilic samples, the synthesized surfactant was successfully intercalated into the layers of clay by its full molecular length and such an intercalation generated a paraffin-like structure in the modified clays. By forming the C-C bonds between surfactants and oligomers/monomers during subsequent radical photoinduced polymerization, the hybrid comprising organophilic clay/oligomers/monomers became an intercalated nanocomposite resin. The thickness of the dispersed lamellae was less than 100 nm, as revealed by transmission electron microscopy (TEM). For the composite sample containing 5.0 wt.% of organophilic clay, the decomposition temperatures raised at least 15 degrees C; the transmittance detected by UV-visible spectrometer showed a less than 15% loss in the visible light region but a satisfactory transparency was still retained, and the degree of moisture absorption decreased from 3.4% to about 1% due to dispersive organophilic clay in the polymer matrix.
Highly efficient electrophosphorescent devices with saturated red emission from a neutral osmium complex
(2005-06-28)
Niu, YH
;
Tung, YL
;
Chi, Y
;
Shu, CF
;
Kim, JH
Highly efficient electrophosphorescent polymer light-emitting diodes (LEDs) with saturated red emission (Commission Internationale de L'Eclairage chromaticity coordinates exactly at x = 0.67, y = 0.33) are achieved by blending a novel neutral Osmium complex into a single-component bipolar polymer host that possesses balanced hole- and electron-transporting ability. By using a tetraphenylenebiphenyldiamine (TPD)-based cross-linkable hole-transport layer as well as a layer of 1,3,5-tris(N-phenylbenzimidazol-2-yl)benzene (TPBI) as an electron-tran sport layer, a device structure with both effective hole/electron injection and efficient carriers/excitons blocking or confinement at both electrode sides is constituted. In this way, external quantum efficiency 12.8% is reached the first time with an organometallic complex with heavy metal core other than iridium.
Band gap variation of size-controlled ZnO quantum dots synthesized by sol-gel method
(2005-06-30)
Lin, KF
;
Cheng, HM
;
Hsu, HC
;
Lin, LJ
;
Hsieh, WF
ZnO quantum dots were synthesized successfully via a simple sol-gel method. The average size of quantum dots can be tailored using well-controlled concentration of zinc precursor. Size-dependent blue shifts of photoluminescence and absorption spectra revealed the quantum confinement effect. The band gap enlargement is in agreement with the theoretical calculation based on the effective mass model. Furthermore, as the particle size decreases, we observed an increase in the size-dependent Stokes shift of the photoluminescence peak relative to the absorption onset. (c) 2005 Elsevier B.V. All rights reserved.
Sol-gel-derived Zn((1-x))Mg(x)O thin films used as active channel layer of thin-film transistors
(2005-07-01)
Lee, JH
;
Lin, P
;
Lee, CC
;
Ho, JC
;
Wang, YW
Sol-gel derived n-type Zn((1-x))Mg(x)O (x = 0-0.45) thin films and thin-film transistors (TFTs) with active channel layers made of the films were investigated. The films were prepared at 500 degrees C. The effects of Mg doping on the crystallinity, optical transparency, grain size, and charge-carrier concentration (n) of the films were examined. The Fermi level of the films, as derived from the temperature dependence of n, was similar to 0.12eV below the conduction band. The donor concentration and donor level (E(d)) were derived by a curve fitting method based on the electrical neutrality condition. Ed was found to be similar to 0.3 eV below the conduction band. The composition dependence of the TFT output characteristics was interpreted and correlated to the width of the depletion region adjacent to the grain boundaries. When the grains were almost depleted at x = 0.2, the TFT showed an enhancement mode and an on/off ratio of 10(6).
A convenient solver for solving optimal control problems
(2005-07-01)
Huang, CH
;
Tseng, CH
;
機械工程學系
;
Department of Mechanical Engineering
This paper focuses on the development of a solver for solving optimal control problems. A developed numerical optimal control module integrated with the Sequential Quadratic Programming method is introduced. An optimal control problem solver based on the proposed method is implemented to solve optimal control problems efficiently in engineering applications. In addition, a systematic procedure for solving optimal control problems by using the optimal control problem solver is also proposed. A time-optimal benchmark problem presented in the literature is used to illustrate for the capability and facility of solving optimal control problems. The numerical results demonstrate the proposed method and the procedure suggested in this paper are helpful to engineers in solving optimal control problems in a systematic and efficient manner.
A robust high-Q micromachined RF inductor for RFIC applications
(2005-07-01)
Lin, JW
;
Chen, CC
;
Cheng, YT
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this paper, a robust micromachined spiral inductor with a cross-shaped sandwich membrane support is proposed and fabricated with fully CMOS compatible post-processes for radio frequency integrated circuit (RFIC) applications. Via the incorporation of a sandwich dielectric membrane (0.7 mu M SiO2/0.7 mu M Si3N4/0.7 mu m TEOS) to enhance the structure rigidity, the inductor can have better signal stability. In comparison, the new design of a similar to 5-nH micromachined inductor can have 45% less inductance variation than the one without the dielectric support while both devices are operated with 10 m/s(2) acceleration. Meanwhile, using a cross shape instead of blanket membrane can also effectively eliminate the inductance variation induced by the working temperature change (20 degrees C to 75 degrees C). The measurement results show the robust inductor can have similar electrical performance to the as-fabricated freely suspended inductor, which has five times Q (quality factor) improvement than the inductor without the substrate removal. It is our belief that the new micromachined inductors can have not only high-Q performance but also better signal stability suitable for wide-range RFIC applications.
Machine learning with automatic feature selection for multi-class protein fold classification
(2005-07-01)
Huang, CD
;
Liang, SF
;
Lin, CT
;
Wu, RC
;
電控工程研究所
In machine learning, both the properly used networks and the selected features are important factors which should be considered carefully. These two factors will influence the result, whether for better or worse. In bioinformatics, the amount of features may be very large to make machine learning possible. In this study we introduce the idea of feature selection in the problem of bioinformatics. We use neural networks to complete our task where each input node is associated with a gate. At the beginning of the training, all gates are almost closed, and, at this time, no features are allowed to enter the network. During the training phase, gates are either opened or closed, depending oil the requirements. After the selection training phase has completed, gates corresponding to the helpful features are completely opened while gates Corresponding to the useless features are closed more tightly. Some gates may be partially open, depending oil the importance of the corresponding features. So, the network can not only select features in an online manner during learning, but it also does some feature extraction. We combine feature selection with our novel hierarchical machine learning architecture and apply it to multi-class protein fold classification. At the first level the network classifies the data into four major folds: all alpha, all beta, alpha + beta and alpha/beta. In the next level, we have another set of networks which further classifies the data into twenty-seven folds. This approach helps achieve the following. The gating network is found to reduce the number of features drastically. It is interesting to observe that, for the first level using just 50 features selected by the gating network, we can get a test accuracy comparable to that using 125 features in neural classifiers. The process also helps us get a better insight into the folding process. For example, tracking the evolution of different gates, we call find which characteristics (features) of the data are more important for the folding process. Eventually, it reduces the computation time. The use of the hierarchical architecture helps LIS get a better performance also.
Histidine residue at position 234 of oxidosqualene-lanosterol cyclase from Saccharomyces cerevisiae simultaneously influences cyclization, rearrangement, and deprotonation reactions
(2005-07-01)
Wu, TK
;
Liu, YT
;
Chang, CH
;
應用化學系分子科學碩博班
;
Institute of Molecular science
Histidine Residue at Position 234 of Oxidosqualene-Lanosterol Cyclase from Saccharomyces cerevisiae Simultaneously Influences Cyclization, Rearrangement, and Deprotonation Reactions
雙觸發矽控整流元件與使用其之靜電保護電路
(2005-07-01)
柯明道
;
徐國鈞
一種雙觸發矽控整流元件與使用其之靜電保護電路。此種雙觸發矽控整流元件係在一個P型基底中配置了數個N＋擴散區域、數個P＋擴散區域、第一N型井區域、第二N型井區域和第三N型井區域。每一個N＋擴散區域和P＋擴散區域中間，都以淺溝渠結構加以隔離。在P＋擴散區域內的其中二個，係雙觸發矽控整流元件的P型觸發區。而在N＋擴散區域內的其中二個，係雙觸發矽控整流元件的N型觸發區。
Electron-phonon-impurity interference effect in disordered Au56Pd44 and IrO2 thick films
(2005-07-01)
Yeh, SS
;
Lin, JJ
;
Jing, XN
;
Zhang, DL
;
電子物理學系
We have fabricated a series of Au56Pd44 thick films with a wide range of residual resistivity rho(0) varying from 40 to 280 mu Omega cm. The resistivities of these films were measured between 15 and 300 K. We found that at temperatures below about 0.1 theta(D) (theta(D) is the Debye temperature), the interference mechanism between the elastic electron scattering and electron-phonon scattering (the electron-phonon-impurity interference effect) contributes significantly to the measured resistivities. Our results support the current theoretical idea that this interference-mechanism-induced resistivity varies with rho(0)T(2), where T is the temperature. Similar observation has also been made in disordered, conducting transition-metal oxide IrO2 thick films.
Punching shear strength of reinforced concrete slabs strengthened with glass fiber-reinforced, polymer laminates
(2005-07-01)
Chen, CC
;
Li, CY
;
土木工程學系
;
Department of Civil Engineering
This study investigates the punching shear strength and failure behavior of reinforced concrete slabs strengthened with glass fiber-reinforced polymer (GFRP) laminates. The parameters of the 18 specimens.studied herein are concrete compressive strength, steel reinforcement ratio, and the number of GFRP laminate layers. The specimens were tested simply supported along the four sides of the slabs and loaded through the stub column. The behavior of the concrete slabs reinforced with GFRP laminates in addition to steel reinforcement is compared to that of slabs with steel reinforcement. Experimental test results indicate that applying GFRP laminates markedly increases the punching shear capacity of slab-column connections. Based on these results, a design procedure is presented to calculate the ultimate punching shear strength of slab-column connections strengthened by the GFRP laminates. Good correlations between predicted and experimental results have been achieved.
Performance and reliability of poly-Si TFTs on FSG buffer layer
(2005-07-01)
De Wang, S
;
Chang, TY
;
Chien, CH
;
Lo, WH
;
Sang, JY
A novel and process-compatible scheme for fabricating poly-Si thin-film transistors (TFTs) on an FSG buffer layer was proposed and demonstrated. Experimental results reveal that remarkably improved device performance and uniformity can be achieved with appropriate fluorine concentration. The poly-Si TFTs fabricated on FSG layers have a higher on-current, a lower leakage current, and a higher field-effect mobility compared with the conventional poly-Si TFTs. Furthermore, the incorporation of fluorine also increased the reliability of poly-Si TFTs against hot carrier stressing, which is attributed to the formation of Si-F bonds.
網路經濟時代下企業整合型資料庫建置暨應用效益－以NIIS中央資料庫建置為例
(2005-07-01)
邱瑞科
;
郭建吾
;
陳聖棋
;
Ruey-Kei Chiu
;
Chien-Wu Kuo
本研究提出一個建置企業整合型資料庫的設計架構，它藉由資料選擇性複製策略的方式，將分散於各地方的資料庫萃取並彙整至企業營運總部，建立一個可以更有效提供企業管理及決策所需資訊的整合型企業資料庫。本研究並以我國衛生署疾病管制局預防接種管理系統(National Immunization Information System, NIIS)之實驗性中央資料庫設計及建立為研究之實作案例，將分散於各縣市衛生局、衛生所之預防接種相關資料庫進行彙集並整合建立一個可有效支援建立全國預防接種管理及決策系統所需資料來源之中央資料庫。為實證中央資料庫建置可更有效支援NIIS決策支援之真實價值，本研究乃進一步嘗試應用本研究所建立的中央資料庫作為資料來源，建立可支援我國年度疫苗接種採購預測模式，提供疾病管制局作為年度各類型疫苗最適採購量之依據，用以取代原有以人工經驗計算之方式。在此一決策應用的研究中，第一階段推估分別應用灰色預測模式及倒傳遞類神經網路預測模式，根據歷年地方衛生所疫苗施打人數、疫苗施打完成率及新年度疫苗施打的目標人數，建構新年度疫苗施打人數預測模式，實驗結果顯示，倒傳遞應用類神經網路比灰色理論可以獲得較佳的預測值。第二階段應用第一階段所得之新年度疫苗施打人數預測量，進一步合併考量疫苗耗損率、保留庫存及上年度之疫苗庫存量等因素進行全國性新年度預防接種疫苗最適採購量之計算。實驗性中央資料庫系統建置完成後，由實證結果得知，應用中央資料庫為資料來源所建立之年度疫苗採購量預測模式相較於傳統人工計算模式能夠得到更精準的下年度疫苗採購量。它不僅可對疫苗採購之最佳化規劃提供最完整的資料來源，更可提供快速支援全國性預防接種管理性統計分析報表及資訊產生之功能。
Query processing in a mobile computing environment: Exploiting the features of asymmetry
(2005-07-01)
Peng, WC
;
Chen, MS
;
資訊工程學系
;
Department of Computer Science
With the cutting edge technology advance in wireless and mobile computers, the query processing in a mobile environment involves join processing among different sites which include static servers and mobile computers. Because of the need for energy saving and also the presence of asymmetric features in a mobile computing environment, the conventional query processing for a distributed database cannot be directly applied to a mobile computing system. In this paper, we first explore three asymmetric features of a mobile environment. Then, in light of these features, we devise query processing methods for both join and query processing. Intuitively, employing semijoin operations in a mobile computing environment is able to further reduce both the amount of data transmission and energy consumption. A semijoin which is initiated by a mobile computer ( respectively, the server) and is beneficial to reduce the cost of a join operation is termed a mobile- initiated or MI ( respectively, server- initiated or SI) profitable semijoin. According to those asymmetric features of a mobile computing system, we examine three different join methods and devise some specific criteria to identify MI/ SI profitable semijoins. For query processing, which refers to the processing of multijoin queries, we develop three query processing schemes. In particular, we formulate the query processing in a mobile computing system as a two- phase query processing procedure that can determine a join sequence and interleave that join sequence with SI profitable semijoins to reduce both the amount of data transmission and energy consumption. Performance of these join and query methods is comparatively analyzed and sensitivity analysis on several parameters is conducted. Furthermore, we develop a systematic procedure to derive the characteristic functions of MI and SI profitable semijoins. It is noted that, given some system parameters, those characteristic functions are very important in determining which join method is the most appropriate one to employ in that configuration. It is shown by our simulation results that, by exploiting the three asymmetric features, these characteristic functions are very powerful in reducing both the amounts of energy consumption and data transmission incurred and can lead to the design of an efficient and effective query processing procedure for a mobile computing environment.
Synthesis and magnetic properties of highly arrayed nickel-phosphate nanotubes
(2005-07-01)
Lin, SC
;
Chen, SY
;
Cheng, SY
;
Lin, JC
;
交大名義發表
In this study, nanotube arrays of nickel-phosphate have been developed by electroless deposition into sub-micro to nanometer sized pores of the porous alumina templates by hypophosphite electrolytic solution composed of NiSO4, NaH2PO2, NaC2H3O2 and Na3C6H5O7 at 80-100 degrees C and PH = 3-6. The dimension of the formed nanotubes has 1 mu m in length, 200-300 nm in diameter and 80-150 nm in thickness of tube walls. Transmission electron microscopy examination of the nanotubes clearly show amorphous hallow structure with a average grain size of similar to 5 nm. The hysteresis loops of the nanotube arrays show a coercive field of about 200 Oe under treatment in 95%N-2/5%H-2 atmosphere at 500 degrees C as the magnetic field was applied along parallel and perpendicular to tube axis. The nanotube arrays also exhibit an anisotropic magnetic property with easier saturation along the perpendicular direction. However, both coercive field and saturation of remanent magnetization of the nanotube arrays become lower while continually increasing heat treatment temperature up to 900 degrees C. (c) 2005 Elsevier SAS. All rights reserved.