Browsing by Issue Date, starting with "2014-04-07"

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Anisotropic strain, magnetic properties, and lattice dynamics in self-assembled multiferroic CoFe2O4-PbTiO3 nanostructures
(2014-04-07)
Tsai, C. Y.
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Chen, H. R.
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Chang, F. C.
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Kuo, H. H.
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Cheng, H. M.
We investigate the anisotropic stress dependent magnetic and phonon behaviors in self-assembled CoFe2O4-PbTiO3 (CFO-PTO) nanostructures deposited on SrRuO3 buffered SrTiO3 substrates of various thickness. The increased vertical compressed stress with increasing thickness enhances the vertical magnetic anisotropy of CFO while gradually reducing the vertical polarization of PTO. By applying the magnetic-field dependent Raman scattering, the CFO-A(1g) and T-2g(1) phonon frequencies shift oppositely because of the magnetostriction. Moreover, the PTO-A(1) mode intensities anomalously enhance and the A(1) and E mode frequencies, respectively, increase and decrease, which prove the existence of the stress-mediated magnetoelectric (ME) effect. This study shows that the ME transmission process is dominated by interfacial stress, which is critical for enhancing the ME efficiency. (C) 2014 AIP Publishing LLC.
Liquid crystal terahertz phase shifters with functional indium-tin-oxide nanostructures for biasing and alignment
(2014-04-07)
Yang, Chan-Shan
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Tang, Tsung-Ta
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Pan, Ru-Pin
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Yu, Peichen
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Pan, Ci-Ling
Indium Tin Oxide (ITO) nanowhiskers (NWhs) obliquely evaporated by electron-beam glancing-angle deposition can serve simultaneously as transparent electrodes and alignment layer for liquid crystal (LC) devices in the terahertz (THz) frequency range. To demonstrate, we constructed a THz LC phase shifter with ITO NWhs. Phase shift exceeding pi/2 at 1.0 THz was achieved in a similar to 517 mu m-thick cell. The phase shifter exhibits high transmittance (similar to 78%). The driving voltage required for quarter-wave operation is as low as 5.66 V (rms), compatible with complementary metal-oxide-semiconductor (CMOS) and thin-film transistor (TFT) technologies. (C) 2014 AIP Publishing LLC.
Surfactant Uptake Dynamics in Mammalian Cells Elucidated with Quantitative Coherent Anti-Stokes Raman Scattering Microspectroscopy
(2014-04-07)
Okuno, Masanari
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Kano, Hideaki
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Fujii, Kenkichi
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Bito, Kotatsu
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Naito, Satoru
The mechanism of surfactant-induced cell lysis has been studied with quantitative coherent anti-Stokes Raman scattering (CARS) microspectroscopy. The dynamics of surfactant molecules as well as intracellular biomolecules in living Chinese Hamster Lung (CHL) cells has been examined for a low surfactant concentration (0.01 w%). By using an isotope labeled surfactant having CD bonds, surfactant uptake dynamics in living cells has been traced in detail. The simultaneous CARS imaging of the cell itself and the internalized surfactant has shown that the surfactant molecules is first accumulated inside a CHL cell followed by a sudden leak of cytosolic components such as proteins to the outside of the cell. This finding indicates that surfactant uptake occurs prior to the cell lysis, contrary to what has been believed: surface adsorption of surfactant molecules has been thought to occur first with subsequent disruption of cell membranes. Quantitative CARS microspectroscopy enables us to determine the molecular concentration of the surfactant molecules accumulated in a cell. We have also investigated the effect of a drug, nocodazole, on the surfactant uptake dynamics. As a result of the inhibition of tubulin polymerization by nocodazole, the surfactant uptake rate is significantly lowered. This fact suggests that intracellular membrane trafficking contributes to the surfactant uptake mechanism.
Dimming-discrete-multi-tone (DMT) for simultaneous color control and high speed visible light communication
(2014-04-07)
Sung, Jiun-Yu
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Chow, Chi-Wai
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Yeh, Chien-Hung
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光電工程學系
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Department of Photonics
Visible light communication (VLC) using LEDs has attracted significant attention recently for the future secure, license-free and electromagnetic-interference (EMI)-free optical wireless communication. Dimming technique in LED lamp is advantageous for energy efficiency. Color control can be performed in the red-green-blue (RGB) LEDs by using dimming technique. It is highly desirable to employ dimming technique to provide simultaneous color and dimming control and high speed VLC. Here, we proposed and demonstrated a LED dimming control using dimming-discrete-multi-tone (DMT) modulation. High speed DMT-based VLC with simultaneous color and dimming control is demonstrated for the first time to the best of our knowledge. Demonstration and analyses for several modulation conditions and transmission distances are performed, for instance, demonstrating the data rate of 103.5 Mb/s (using RGB LED) with fast Fourier transform (FFT) size of 512. (C) 2014 Optical Society of America
交大e-News第160期
(2014-04-07)
Secretariat
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國立交通大學秘書室
High-repetition-rate quasi-CW side-pumped mJ eye-safe laser with a monolithic KTP crystal for intracavity optical parametric oscillator
(2014-04-07)
Cho, C. Y.
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Chen, Y. C.
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Huang, Y. P.
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Huang, Y. J.
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Su, K. W.
We demonstrate a high-repetition-rate millijoule passively Q-switched eye-safe Nd:YVO4 laser pumped by a quasi-CW diode stack. A theoretical analysis has been explored for the design criteria of generating TEMn,0 mode in the diode-stack directly side-pumping configuration. We successfully generate TEMn,0 modes at 1064 nm by adjusting the gain medium with respected to the laser axis. We further observe the spatial cleaning ability for generating an nearly TEM0,0 mode output at 1573 nm with a monolithic OPO cavity. At the repetition rate up to 200 Hz, the output pulse energy reaches 1.21 mJ with the threshold pump energy of 17.9 mJ. (C) 2014 Optical Society of America
Single-ended SRAM with cross-point data-aware write operation
(2014-04-08)
Jou Shyh-Jye
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Lin Jhih-Yu
;
Chuang Ching-Te
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Tu Ming-Hsien
;
Chiu Yi-Wei
A single-ended SRAM including at least one memory cell and a third switch is provided. The memory cell includes a data-latching unit, a first switch, a second switch and a data-transferring unit. The data-latching unit is configured for latching the received input data and provides a storage data and the inverse data of the storage data. The first switch transfers a reference data to the data-latching unit according to a first word-line signal. The second switch transfers the reference data to the data-latching unit according to a second word-line signal. The data-transferring unit decides whether or not to transfer the reference data to the bit-line according to the storage data and a control signal. The third switch receives the reference data and the control signal and transfers the reference data to the first switch, the second switch and the data-transferring unit according to the control signal.
Parameter extraction method for semiconductor device
(2014-04-08)
Guo Jyh-Chyurn
;
Yeh Kuo-Liang
A parameter extraction method for semiconductor devices includes: providing a first multi-finger device and a second multi-finger device, wherein the gate-finger numbers between the first and second multi-finger devices are different; performing an open de-embedding, then the high-frequency test apparatus measuring a first intrinsic gate capacitance of the first multi-finger device and a second intrinsic gate capacitance of the second multi-finger device; calculating a slope according to the first and second intrinsic gate capacitances, and the first and second gate-finger numbers; performing a 3D capacitance simulation for computing the poly finger-end fringing capacitances; utilizing a long channel device for measuring the gate capacitance and extracting the intrinsic gate capacitance, then calculating an inversion channel capacitance per unit area; and computing a delta channel width of the semiconductor device, according to the slope, the poly finger-end fringing capacitance, and the inversion channel capacitance per unit area.
Control circuit for switching loss reduction and smooth mode transition of a high efficiency buck-boost power converter
(2014-04-08)
Chen Ke-Horng
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Wu Wei-Quan
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Ho Hsin-Hsin
A buck-boost power converter switches the switches thereof with a novel sequence and extends the switching periods of the switches to reduce the switching loss and conduction loss when the input voltage thereof approaches the output voltage thereof. The influence of the load current of the power converter on the duty thereof is taken into account to switch the power converter between modes at correct time points, so as to prevent the output voltage from being affected by the mode switching.
Method for removing germanium suboxide
(2014-04-08)
Liu Po-Tsun
;
Huang Chen-Shuo
A method for removing germanium suboxide between a germanium (Ge) substrate and a dielectric layer made of metal oxide includes causing a supercritical fluid composition that includes a supercritical carbon dioxide fluid and an oxidant to diffuse into the germanium suboxide such that metal residues in the dielectric layer, the germanium suboxide and the oxidant are subjected to a redox reaction so as to reduce the germanium suboxide into germanium.
劉康國客家話從家扎根
(2014-04-09)
王泓文
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Department of Communication and Technology
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傳播與科技學系
漫步於九讚頭的鄉間小道，一排排低矮的客家建築中，一座頗具現代感的鄉公所矗立在眼前。走進鄉公所，公務員們忙碌於各自的事務無暇抬頭，似乎沒有發現任何人，只有一個人微笑地揮手示意，他就是劉康國。
彭瑞雲　一顆野薑花粽讓你想到內灣
(2014-04-09)
尤意茹
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Department of Communication and Technology
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傳播與科技學系
內灣是位於新竹縣橫山鄉靠山區的小聚落，曾經因礦業而繁榮興盛，但也跟大多數的礦區一樣，因為礦產資源殆盡而沒落，年輕人紛紛出外到大都市打拚。內灣媳婦彭瑞雲從學校退休後，原本跟著丈夫經營內灣唯一的一間藥局，夫妻倆發現許多老人常裝病只是為了讓離鄉的年輕人回家，感到十分不捨，於是下定決心要改造內灣，為小鎮找回充沛的生命力，藉著政府推動一鄉一特色的機會，彭瑞雲也擔任內灣社區發展協會的第一屆理事長，最後發掘了「野薑花粽」這個深具客家與地方特色的美食。
董秀珍　認識客家，認同客家，喜歡客家
(2014-04-09)
鄭豪
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Department of Communication and Technology
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傳播與科技學系
「同學，你先慢慢參觀，等一下我忙完馬上就來。」不管是一個人獨自參觀，或者是一群遊客，董秀珍總是熱情地接待跟導覽劉興欽老師的漫畫作品。原是宜蘭三星人的董秀珍，因為工作的緣故一直都是待在台北，後來因為想到新竹這邊只剩下公婆，於是她毅然決然的搬回了新竹橫山鄉這個客家文化濃厚的地方，成為當地客家文化的一份子。她接下在地文化推廣的工作，於是就有了劉興欽漫畫館的誕生。
Improved Efficiency of a Large-Area Cu(In,Ga)Se-2 Solar Cell by a Nontoxic Hydrogen-Assisted Solid Se Vapor Selenization Process
(2014-04-09)
Wu, Tsung-Ta
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Hu, Fan
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Huang, Jyun-Hong
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Chang, Chia-ho
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Lai, Chih-chung
A nontoxic hydrogen-assisted solid Se vapor selenization process (HASVS) technique to achieve a large-area (40 X 30 cm(2)) Cu(In,Ga)Se-2 (CIGS) solar panel with enhanced efficiencies from 7.1 to 10.8% (12.0% for active area) was demonstrated. The remarkable improvement of efficiency and fill factor comes from improved open circuit voltage (V-oc) and reduced dark current due to (1) decreased interface recombination raised from the formation of a widened buried homojunction with n-type Cd-cu participation and (2) enhanced separation of electron and hole carriers resulting from the accumulation of Na atoms on the surface of the CIGS film. The effects of microstructural, compositional, and electrical characteristics with hydrogen-assisted Se vapor selenization, including interdiffusion of atoms and formation of buried homojunction, were examined in detail. This methodology can be also applied to CIS (CuInSe2) thin film solar cells with enhanced efficiencies from 5.3% to 8.5% (9.4% for active area) and provides a facile approach to improve quality of CIGS and stimulate the nontoxic progress in the large scale CIGS PV industry.
Synthesis and Characterization of One-Dimensional Ag-Doped ZnO/Ga-Doped ZnO Coaxial Nanostructure Diodes
(2014-04-09)
Chiu, Hsien-Ming
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Chang, Yu-Tsui
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Wu, Wen-Wei
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Wu, Jenn-Ming
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材料科學與工程學系
In the pursuit of high injection current diode nanodevices, entire one-dimensional (1D) ZnO coaxial nanostructures with p-n homojunctions is one of the ideal structures. In this study, we synthesized entire 1D ZnO-based coaxial homojunction diodes with p-type Ag-doped ZnO (SZO) nanostructure shells covering n-type Ga-doped ZnO (GZO) nanopagoda (NPG) cores by a metal organic chemical vapor deposition (MOCVD) technique. The entire ID SZO-GZO and SZO-ZnO coaxial nanostructures exhibit better diode characteristics, such as lower threshold voltage, better rectification ratios, and better ideality factor n, than that reported for either 2D or 2D-1D p-n heterojunction and/or homojunction diodes. The binding energies of Ga and Ag were evaluated by low-temperature and temperature-dependent photoluminescence. In comparison, the SZO-GZO coaxial p-n nanostructures display better diode performance than the SZO-ZnO ones.
楊晴子打造客家版LV
(2014-04-09)
林慰
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Department of Communication and Technology
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傳播與科技學系
漫步在東勢本街這條老街上，古色古香的巷弄，街道兩側的建築物新舊參半，濃濃的老街風情，耳邊傳來的是獨特的東勢大埔客家話，而社團法人台中縣東勢愛鄉協進會會所就坐落在這條本街上。會所大門前掛了許多客家花布燈籠，隨風搖擺。開門迎人的是一位滿臉笑容、和藹可親的老媽媽，她穿著淡灰色的針織外套及深色長褲，顯得十分舒適，還有許多人熱情地向人緣好的她打招呼。她，就是楊晴子——東勢愛鄉協進會的執行長。
A mechanistic stress model of protein evolution accounts for site-specific evolutionary rates and their relationship with packing density and flexibility
(2014-04-09)
Huang, Tsun-Tsao
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del Valle Marcos, Maria Laura
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Hwang, Jenn-Kang
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Echave, Julian
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生物資訊及系統生物研究所
Background: Protein sites evolve at different rates due to functional and biophysical constraints. It is usually considered that the main structural determinant of a site's rate of evolution is its Relative Solvent Accessibility (RSA). However, a recent comparative study has shown that the main structural determinant is the site's Local Packing Density (LPD). LPD is related with dynamical flexibility, which has also been shown to correlate with sequence variability. Our purpose is to investigate the mechanism that connects a site's LPD with its rate of evolution. Results: We consider two models: an empirical Flexibility Model and a mechanistic Stress Model. The Flexibility Model postulates a linear increase of site-specific rate of evolution with dynamical flexibility. The Stress Model, introduced here, models mutations as random perturbations of the protein's potential energy landscape, for which we use simple Elastic Network Models (ENMs). To account for natural selection we assume a single active conformation and use basic statistical physics to derive a linear relationship between site-specific evolutionary rates and the local stress of the mutant's active conformation. We compare both models on a large and diverse dataset of enzymes. In a protein-by-protein study we found that the Stress Model outperforms the Flexibility Model for most proteins. Pooling all proteins together we show that the Stress Model is strongly supported by the total weight of evidence. Moreover, it accounts for the observed nonlinear dependence of sequence variability on flexibility. Finally, when mutational stress is controlled for, there is very little remaining correlation between sequence variability and dynamical flexibility. Conclusions: We developed a mechanistic Stress Model of evolution according to which the rate of evolution of a site is predicted to depend linearly on the local mutational stress of the active conformation. Such local stress is proportional to LPD, so that this model explains the relationship between LPD and evolutionary rate. Moreover, the model also accounts for the nonlinear dependence between evolutionary rate and dynamical flexibility.
劉桂心　端出美食九二一後重新站起來
(2014-04-09)
戴裕蒨
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Department of Communication and Technology
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傳播與科技學系
出生於東勢鎮大茅埔的劉桂心，人稱「桂花媽媽」。從小就住在這個典型的客家聚落，她總盼望著有一天可以離開這個鄉下地方，到繁華的台中市討生活。後來，她也真的在台中市區有了自己的家，圓了兒時的夢。然而，一九九九年的九二一大地震，大茅埔的災情慘重，讓劉桂心決心回到家鄉，為自己從小生長的地方付出一份心力。
林保光竹縣議員奔走不願珍貴文化在這一代消失
(2014-04-09)
林芷瑩
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Department of Communication and Technology
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傳播與科技學系
林保光是客家籍的新竹縣議員，也是目前唯一代表新竹縣竹北市六家的縣議員。在這個地方，林家世世代代已生活長達二百五十年多年了，祖先所蓋的客家傳統祖厝，一直保留至今，並成為竹北著名的客家古蹟─「新瓦屋」。林家與六家地區關係濃厚，而從小就生活在這個客家庄的林保光，精通客家中最艱深的饒平話，對家鄉有很深的情感，對自己的家鄉付出不遺餘力。
An EEG-based brain-computer interface for dual task driving detection
(2014-04-10)
Wang, Yu-Kai
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Chen, Shi-An
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Lin, Chin-Teng
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資訊工程學系
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腦科學研究中心
The development of brain-computer interfaces (BCI) for multiple applications has undergone extensive growth in recent years. Since distracted driving is a significant cause of traffic accidents, this study proposes one BCI system based on EEG for distracted driving. The removal of artifacts and the selection of useful brain sources are the essential and critical steps in the application of electroencephalography (EEG)-based BCI. In the first model, artifacts are removed, and useful brain sources are selected based on the independent component analysis (ICA). In the second model, all distracted and concentrated EEG epochs are recognized with a self-organizing map (SOM). This BCI system automatically identified independent components with artifacts for removal and detected distracted driving through the specific brain sources which are also selected automatically. The accuracy of the proposed system approached approximately 90% for the recognition of EEG epochs of distracted and concentrated driving according to the selected frontal and left motor components. (C) 2013 Published by Elsevier B.V.