Browsing by Issue Date, starting with "2005-08-01"

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Discovering common structural motifs of ribosomal RNA secondary structures in prokaryotes
(2005-08-01)
Huang, HD
;
Horng, JT
;
Wu, LC
;
Fang, SF
;
生物資訊及系統生物研究所
Certain structural motifs, like tetra-loops, in ribosomal RNA are known to functionally implicate in virtually every aspect of protein synthesis. Ribosomal RNA molecules were also widely used as a tool in molecular evolutionary studies because of their ubiquity, size and low evolutionary rate. In this study, we adapt a data mining approach to discover common structural motifs, and then we use a machine learning approach to identify discriminating CSMs from groups of organisms. Finally, we construct phylogeneitc trees to investigate the evolution of ribosomal RNA by serving the CSMs discovered as targets, which are used to estimate the evolutionary relatedness between organisms. The aim of this study is to discover common structural motifs (CSMs), i.e., those single-strain regions shared in ribosomal RNA secondary structures by several organisms, which are related to specific domains or functions. We discover a set of common structural motifs from several data sets of Archaea and Bacteria. Significant CSMs are then induced by a decision tree. Furthermore, phylogenetic trees are constructed based on CSMs and primary sequences of SSU 16 S ribosomal RNA.
磁光式之近場光學光儲存元件
(2005-08-01)
徐文祥
;
謝漢萍
;
孫翊庭
本發明係提供一種磁光式之近場光學光儲存元件，係先利用犧牲層製作空氣軸承結構；再定義一初始小孔，並以電鍍法縮小該孔至奈米等級，再以兩次之厚膜光阻層配合兩次電鍍製程，製作高深寬比之金屬線圈結構與金屬內連線；可有效利用面積與降低電阻，最後利用微影製程中對不同區域的不同曝光量控制，定義單層光阻形成具有特定尺寸且不同厚度之結構，接著配合回流(reflow)即可利用一連續製程製作出結合超半球固態浸沒式透鏡(solid immersion lens)、奈米微孔、金屬線圈、空氣軸承之磁光(MO)讀取頭，而不需精密昂貴的設備，並可批次大量生產，免去組裝的步驟，並且不用高精密度之儀器即可製作，達到高資料儲存與複寫。
超半球固態浸沒式透鏡之製法
(2005-08-01)
徐文祥
;
孫翊庭
本發明係提供一種超半球固態浸沒式透鏡之製法，係於一基材上塗佈正光阻層後，以第一、二片光罩進行第一、二次曝光，可經由第一次足量曝光在正光阻層上產生之圖案來進行對準，使得第二片光罩上之曝光圖案可經由對準轉移到正光阻層上的特定區域，接著進行回流(reflow)，即可形成超半球固態浸沒式透鏡(SSIL)；可使整個製程容易而不需昂貴或是複雜的設備即可完成，且方便利用後續的半導體製程額外製作其他光學元件；與已製作之超半球固態浸沒式透鏡(SSIL)作整合，所以不需組裝即可製作具有功能性的元件，進而達到易於製作，且應用面廣泛易與其他光學元件作整合，利於批次大量生產。
Optical properties of a novel yellow fluorescent dopant for use in organic LEDs
(2005-08-01)
Choy, WCH
;
Wu, YS
;
Chen, CH
;
Cheah, KW
;
電子與資訊研究中心
In this paper, the optical properties of a novel organic, 2,8-di(t-butyl)-5,11-di[4(t-butyl)phenyl]-6,12-diphenylnaphthacene (tetra(t-butyl)rubrene) have been investigated. Our results show that there are two peaks in the photoluminescence (PL) spectra of tetra(t-butyl) rubrene (TBRb) which are also confirmed in the electroluminescence (EL) spectra. Photo-quenching of the PL intensity is observed when the irradiation time increases. It is shown that oxidation is the dominant reason for photo-quenching. The absolute refractive index and absorption coefficient have also been determined and the results correlate well with the PL results. The results show that TBRb can be a good dopant to achieve the Forster energy transfer and to assist light emission. The optical properties of TBRb are similar to those of rubrene; however, the PL of TBRb is much stronger than that of rubrene. Finally, although crystalline organics have been commonly reported by heating the sample, we report crystallization of TBRb at low temperature < 230 K when the TBRb film is in an amorphous form before cooling.
Recursive EM and SAGE-inspired algorithms with application to DOA estimation
(2005-08-01)
Chung, PJ
;
Bohme, JF
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
This paper is concerned with recursive estimation using augmented data. We study two recursive procedures closely linked with the well-known expectation and maximization (EM) and space alternating generalized EM (SAGE) algorithms. Unlike iterative methods, the recursive EM and SAGE-inspired algorithms give a quick update on estimates given new data. Under mild conditions, estimates generated by these procedures are strongly consistent and asymptotically normally distributed. These mathematical properties are valid for a broad class of problems. When applied to direction of arrival (DOA) estimation, the recursive EM and SAGE-inspired algorithms lead to a very simple and fast implementation of the maximum-likelihood (ML) method. The most complicated computation in each recursion is inversion of the augmented information matrix. Through data augmentation, this matrix is diagonal and easy to invert. More importantly, there is no search in such recursive procedures. Consequently, the computational time is much less than that associated with existing numerical methods for finding ML estimates. This feature greatly increases the potential of the ML approach in real-time processing. Numerical experiments show that both algorithms provide good results with low computational cost.
Enhancing the frequency response of cross-polarization wavelength conversion
(2005-08-01)
Wei, CC
;
Huang, MF
;
Chen, J
;
光電工程學系
;
Department of Photonics
This work presents a novel wavelength conversion scheme, differential cross-polarization modulation (DXPoM), using an extra birefringence delay to enhance the performance of the conventional cross-polarization modulation. Simulation and experimental results confirm that the predicted performance is enhanced. Using the proposed scheme improves rise time by over 300 %, reduces timing jitter by 50 %, and increases extinction ratio by 9 %.
製作自行聚合奈米粒之方法
(2005-08-01)
陳衛國
;
李明知
;
周武清
;
陳文雄
;
柯文政
一種用以成長奈米粒的方法，係可在任何晶格匹配度材料之緩衝層上，不需透過圖案遮罩(mask)之製作，即可自行聚合方式(self-assembled)成長包含III-V族、II- VI族或IV-IV族材料之二元、三元以上化合物之奈米粒為特徵。該方法係在基板上先成長任一種材料之緩衝層，然後於適當溫度範圍內完成週期性流量調制磊晶成長，包含：在通入第二反應物前，先通入清除氣體並調制第一反應物至較低第一莫耳流量範圍，致使通入之第二反應物得以在緩衝層上形成金屬或該高金屬含量化合物島狀物，再通入清除氣體以清除殘餘未形成金屬或高金屬含量化合物島狀物之第二反應物，再調制第一反應物至較高第二莫耳流量範圍使該金屬或該高金屬含量化合物島狀物可以形成奈米粒。最後在完成週期性流量調制磊晶成長後，於較高之成長溫度下進行再結晶化步驟，以形成結構性佳之高品質奈米粒。
Overlay metrological system for overlaid linear gratings by an interferoscatterometer
(2005-08-01)
Shyu, DM
;
Lu, MH
;
光電工程學系
;
Department of Photonics
Interferoscatterometry is an optical measurement technology based on the analysis of light scattered and interfered from a periodic structure. In this work, first we build up a model for this system by the rigorous coupled wave analysis. With the model we calculate the diffractive efficiency of overlaid linear gratings with a mirror located in the incident region. Then, from the analyses of the overlaid linear gratings we obtain the best structure which has the highest sensitivity in the interferoscatterometry. Finally, we measure a sample and get experimental signatures. In order to get the overlay between the upper and lower grating, we compare the experimental signatures with theoretical signatures which are built in a library. The application of the interference technique on the scatterometry shows a higher sensitivity and a longer measurement range. (c) 2005 American Institute of Physics.
橫向絕緣閘雙極性電晶體結構
(2005-08-01)
張隆國
;
蔡銘裕
本發明係提供一種橫向絕緣閘雙極性電晶體結構，係使該電晶體之陽極端與陰極端皆為P^＋／N^＋平行對接節段，但卻為分離且對稱式之結構，若以電子／電洞路徑而言，則為電子／電洞路徑完全分離，如此可大幅提高元件之閂鎖電流，改善元件的安全操作區域。並可使該電晶體結合三維降低表面電場原理，使其陽極端／陰極端亦為P^＋／N^＋平行對接節段，而其漂移區則分別是N^–、P^–的平行帶狀區塊，形成一橫向絕緣閘雙極性電晶體與一逆偏PIN飛輪二極體並聯的結構，若以電子／電洞路徑而言則為電子／電洞路徑部份分離，使元件除了在截止狀態時具有高耐壓特性外，在導通狀態時亦具有閂鎖現象的抗受能力。
申請隨班附讀相關事項說明
(國立陽明大學, 2005-08-01)
陽明電子報編輯小組
＜教學服務組／提供＞本校94學年度第1學期申請隨班附讀相關事項如說明，欲申請之學員，應於94年7月20日至94年9月5日前向本校教學服務組辦理申請手續.....
多媒體製作研習課程
(國立陽明大學, 2005-08-01)
陽明電子報編輯小組
＜資訊與通訊中心／提供＞為配合網路教學平台推廣，資通中心規劃一系列相關多媒體製作課程，以提供老師製作多媒體教材之參考，歡迎有興趣者報名參加.....
Fitting Lanchester's square law to the Ardennes Campaign
(2005-08-01)
Hung, CY
;
Yang, GK
;
Deng, PS
;
Tang, T
;
Lan, SP
In this research, we try to improve Bracken's and Chen's work to significantly better fit our extended Lanchester model into the Ardennes Campaign live data. Essentially, we adopt the concepts of the tactical factor variable and the shift time variable to improve the original Lanchester's model. Moreover, we use the Lanchester square law model instead of Lanchester linear law model to reflect the fact that the Ardennes Campaign was not an indirect-fire but a direct-fire combat. According to our numerical experimental result, we improved Bracken's work by 39.26%, and Chen's work by 19.51%. The contribution of this research is that we propose a much better qualitative analysis model for the explanation of modern combat.
「心理健康及諮商輔導」研習
(國立陽明大學, 2005-08-01)
陽明電子報編輯小組
＜人事室／提供＞本校將於本（94）年8月25日上午9時至12時邀請通識中心黃素菲老師假活動中心第一會議室辦理「心理健康及諮商輔導」研習.....
第十四屆全國高中生醫學研習營活動報導
(國立陽明大學, 2005-08-01)
陽明電子報編輯小組
這一天，在醫學營血液學實驗課課堂上，一群來自全省各高中的青年學子，嘰嘰喳喳地嘗試從自己的指尖扎針並抽取一小管血，作成血液抹片，染色後再從顯微鏡中觀察自己的血球究竟是什麼模樣？
全民英檢宣導說明會
(國立陽明大學, 2005-08-01)
陽明電子報編輯小組
＜人事室／提供＞本校將於本（94）年8月4日上午9時30分至11時30分邀請財團法人語言訓練中心前測驗組科長丁亞舟假本校活動中心第一會議室辦理「全民英檢宣導說明會」，請轉所屬準時參加.....
A method to determine the higher order polar anchoring coefficients for the non-twisted liquid crystal cells
(2005-08-01)
Hsu, JS
;
Hsieh, MC
;
Yang, CL
;
Liang, BJ
;
Chen, SH
We propose a method to determine the higher order polar anchoring coefficients for the non-twisted liquid crystal cells. The surface anchoring energy density was determined by measuring the phase retardations as a function of applied voltage. We extended the Rapini-Papoular model and obtained the coefficients of the first and the second terms by analyzing the measured phase retardations with the simulated curves for the homogeneous and homeotropic cells. A discussion of the experimental results is given.
國家衛生研究院博士後研究學者獎助
(國立陽明大學, 2005-08-01)
陽明電子報編輯小組
＜研究發展處／提供＞國家衛生研究院為獎勵優秀博士後研究人才於國內研究單位進行全職博士後研究，特提供「國家衛生研究院博士後研究學者獎助」(NHRI Postdoctoral Fellowship Award).
Patterns generation and transition matrices in multi-dimensional lattice models
(2005-08-01)
Ban, JC
;
Lin, SS
;
應用數學系
;
Department of Applied Mathematics
In this paper we develop a general approach for investigating pattern generation problems in multi-dimensional lattice models. Let S be a set of p symbols or colors, Z(N) a fixed finite rectangular sublattice of Z(d), d >= 1 and N a d-tuple of positive integers. Functions U : Z(d) --> S and U-N : Z(N) --> S are called a global pattern and a local pattern on ZN, respectively. We introduce an ordering matrix X-N for Sigma(N), the set of all local patterns on Z(N). For a larger finite lattice Z((N) over tilde) (N) over tilde >= N, we derive a recursion formula to obtain the ordering matrix X-(N) over tilde of Sigma((N) over tilde) from XN. For a given basic admissible local patterns set 13 C Ely, the transition matrix T-N(B) is defined. For each (N) over tilde >= N denoted by Sigma((N) over tilde)(B) the set of all local patterns which can be generated from B, the cardinal number of Sigma((N) over tilde)(B) is the sum of entries of the transition matrix T-(N) over tilde(B) which can be obtained from T-N(B) recursively. The spatial entropy h(B) can be obtained by computing the maximum eigenvalues of a sequence of transition matrices T-n(B). The results can be applied to study the set of global stationary solutions in various Lattice Dynamical Systems and Cellular Neural Networks.
Single-crystalline MgxZn1-xO (0 <= x <= 0.25) nanowires on glass substrates obtained by a hydrothermal method: growth, structure and electrical characteristics
(2005-08-01)
Lee, CY
;
Tseng, TY
;
Li, SY
;
Lin, P
;
材料科學與工程學系
Single-crystalline Mg-x-Zn1-xO(0 <= x <= 0.25) nanowires (MZONWs) were synthesized on glass substrates by a hydrothermal method using a mixture of an aqueous solution of zinc nitrate hexahydrate, magnesium nitrate hexahydrate and diethylenetriamine at temperatures that ranged from 75 to 105 degrees C. X-ray diffraction, scanning electron microscopy and transmission electron microscopy investigations were carried out to characterize the crystallinity, surface morphologies and orientations of these nanowires, respectively. These nanowires with direct band gaps ranging from 3.21 to 3.95 eV emitted ultraviolet photoluminescence from 406 to 397 nm at room temperature as the Mg content increased. Field emission measurements revealed that the turn-on electric field and threshold electric field (current density of 1 mA cm(-2)) of ZnO NWs are 1.6 and 2.1 V mu m(-1) with the value of 3340. Therefore, low temperature synthesized MZO NWs (0 <= x <= 0.25) with modulated band gaps may be applied in solar cells, light emission devices and other nanoheterojunction devices in the future.
Dissociation of energy-selected c-C2H4S+ in a region 10.6-11.8 eV: Threshold photoelectron-photoion coincidence experiments and quantum-chemical calculations
(2005-08-01)
Fang, YS
;
Lin, IF
;
Lee, YC
;
Chiang, SY
;
應用化學系
Dissociation of energy-selected c-C2H4S+ was investigated in a region of 10.6-11.8 eV with a threshold photoelectron-photoion coincidence technique and a synchrotron as a source of vacuum ultraviolet radiation. Branching ratios and average releases of kinetic energy in channels of formation of c-C2H4S+, CH3CS+, and HCS+ were obtained from well-resolved time-of-flight peaks in coincidence mass spectra. Measured average releases of kinetic energy for channel CH3CS++H of least energy are substantial and much greater than calculated with quasiequilibrium theory; in contrast, small releases of kinetic energy near the appearance onset for channel HCS++CH3 agree satisfactorily with statistical calculations. Calculations of molecular electronic structures and energetics of c-C2H4S+ and C2H3S+ isomers and various fragments and transition states were also performed with Gaussian 3 method to establish dissociation mechanisms. A predicted dissociation energy of 11.05 eV for c-C2H4S -> HCS++CH3 agrees with a linearly extrapolated threshold at 10.99 +/- 0.04 eV and a predicted dissociation mechanism that c-C2H4S+ isomerizes to CH3CHS+ before dissociating to HCS++CH3 supports the experimental results. The large releases of kinetic energy for channel CH3CS++H might result from a dissociation mechanism according to which c-C2H4S+ isomerizes to a local minimum CH3CSH+ and then dissociates through a transition state to form CH3CS++H. (C) 2005 American Institute of Physics.