Browsing by Issue Date, starting with "2014-02-24"

Now showing 1 - 20 of 27589

Improvement of emission uniformity by using micro-cone patterned PDMS film
(2014-02-24)
Liu, Che-Yu
;
Chen, Kuo-Ju
;
Lin, Da-Wei
;
Lee, Chia-Yu
;
Lin, Chien-Chung
Micro-patterned PDMS film was fabricated and combined with LED chip on board (COB) package to improve the emission uniformity of LED chip. The micro scale patterned sapphire substrate (PSS) was used as a mold to fabricate micro-cone patterned PDMS (MC-PDMS) film. A strong scattering effect from this MC-PDMS film can be verified by the high haze ratio and the Bi-directional Transmission effect. The angle dependent color temperature measurement system was used to measure the Delta CCT of COB with and without MC-PDMS. The measurement results indicate that the Delta CCT was reduced from 1025K to 428K. This improvement can effectively eliminate the yellow ring effect of LED chip. This technology can be thus considered as a cost-effective way for the next generation of light source packages. (C) 2014 Optical Society of America
Supercontinuum generation in highly nonlinear fibers using amplified noise-like optical pulses
(2014-02-24)
Lin, Shih-Shian
;
Hwang, Sheng-Kwang
;
Liu, Jia-Ming
;
光電系統研究所
;
Institute of Photonic System
Supercontinuum generation in a highly nonlinear fiber pumped by noise-like pulses from an erbium-doped fiber ring laser is investigated. To generate ultrabroad spectra, a fiber amplifier is used to boost the power launched into the highly nonlinear fiber. After amplification, not only the average power of the noise-like pulses is enhanced but the spectrum of the pulses is also broadened due to nonlinear effects in the fiber amplifier. This leads to a reduction of the peak duration in their autocorrelation trace, suggesting a similar extent of pulse compression; by contrast, the pedestal duration increases only slightly, suggesting that the noise-like characteristic is maintained. By controlling the pump power of the fiber amplifier, the compression ratio of the noise-like pulse duration can be adjusted. Due to the pulse compression, supercontinuum generation with a broader spectrum is therefore feasible at a given average power level of the noise-like pulses launched into the highly nonlinear fiber. As a result, supercontinuum generation with an optical spectrum spanning from 1208 to 2111 nm is achieved using a 1-m nonlinear fiber pumped by amplified noise-like pulses of 15.5 MHz repetition rate at an average power of 202 mW. (C) 2014 Optical Society of America
High spectral efficient W-band optical/wireless system employing Single-Sideband Single-Carrier Modulation
(2014-02-24)
Ho, Chun-Hung
;
Lin, Chun-Ting
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Cheng, Yu-Hsuan
;
Huang, Hou-Tzu
;
Wei, Chia-Chien
With broader available bandwidth, W-band wireless transmission has attracted a lot of interests for future Giga-bit communication. In this article, we experimentally demonstrate W-band radio-over-fiber (RoF) system employing single-sideband single-carrier (SSB-SC) modulation with lower peak-to-average-power ratio (PAPR) than orthogonal frequency division multiplex (OFDM). To overcome the inter-symbol interference (ISI) of the penalty from uneven frequency response and SSB-SC modulation, frequency domain equalizer (FDE) and decision feedback equalizer (DFE) are implemented. We discuss the maximum available bandwidth of different modulation formats between SSB-SC and OFDM signals at the BER below forward error correction (FEC) threshold (3.8 x 10(-3)). Up to 50-Gbps 32-QAM SSB-SC signals with spectral efficiency of 5 bit/s/Hz can be achieved. (C) 2014 Optical Society of America
High-quality planar light emitting diode formed by induced two-dimensional electron and hole gases
(2014-02-24)
Van-Truong Dai
;
Lin, Sheng-Di
;
Lin, Shih-Wei
;
Lee, Yi-Shan
;
Zhang, Yin-Jie
A high-quality planar two-dimensional p-i-n light emitting diode in an entirely undoped GaAs/AlGaAs quantum well has been fabricated by using conventional lithography process. With twin gate design, two-dimensional electron and hold gases can be placed closely on demand. The electroluminescence of the device exhibit high stability and clear transition peaks so it is promising for applications on electrically-driven single photon sources. (C) 2014 Optical Society of America
100-GHz DD-OFDM-RoF system over 150-km fiber transmission employing pilot-aided phase noise suppression and bit-loading algorithm
(2014-02-24)
Huang, Hou-Tzu
;
Liang, Wan-Ling
;
Lin, Chun-Ting
;
Wei, Chia-Chien
;
Chi, Sien
This study extended the transmission distance of a 100-GHz DD-OFDM-RoF system through the reduction of chromatic dispersion-induced phase noise. The implementation of a pilot-aided phase noise suppression (PPNS) scheme enabled the transmission of distance-insensitive 16.97-Gbps QPSK OFDM over 0 similar to 150-km fiber and 2-m air transmission via a DFB laser with linewidth of 1 similar to 10-MHz. We applied a bit-loading algorithm in conjunction with PPNS to maximize spectral efficiency, resulting in a 93% improvement in the data rate from 11.53 to 22.27 Gbps at a fiber transmission of 150 km. (C) 2014 Optical Society of America
Higher-order modulations of fs laser pulses for GHz frequency domain photon migration system
(2014-02-24)
Lin, Huang-Yi
;
Cheng, Nanyu
;
Tseng, Sheng-Hao
;
Chan, Ming-Che
;
影像與生醫光電研究所
Except the fundamental modulation frequency, by higher-order-harmonic modulations of mode-locked laser pulses and a simple frequency demodulation circuit, a novel approach to GHz frequency-domain-photon-migration (FDPM) system was reported. With this novel approach, a wide-band modulation frequency comb is available without any external modulation devices and the only electronics to extract the optical attenuation and phase properties at a selected modulation frequency in FDPM systems are good mixers and lock-in devices. This approach greatly expands the frequency range that could be achieved by conventional FDPM systems and suggests that our system could extract much more information from biological tissues than the conventional FDPM systems. Moreover, this demonstration will be beneficial for discerning the minute change of tissue properties. (C) 2014 Optical Society of America
Low power static random access memory
(2014-02-25)
Chuang Ching-Te
;
Yang Hao-I
;
Hsia Mao-Chih
;
Hwang Wei
;
Chen Chia-Cheng
A SRAM that keeps the memory cell array under a low voltage in the Standby mode and Write mode, and raises the memory cell array supply voltage to a high voltage in the Read mode. A SRAM comprising: at least one memory cell circuit, comprising a latch circuit with at least two inverters, and comprising two power receiving terminals for receiving power; and a power supplying circuit, for providing the power to the memory cell circuit, such that the voltages at the power receiving terminals of the latch circuit is below a predetermined voltage level when data is written to the latch circuit. In one embodiment, the memory cell circuit includes a plurality of data accessing terminals and the data accessing terminals are respectively controlled by at least two pass-transistor switch devices.
Highly Conductive PEDOT:PSS Treated with Formic Acid for ITO-Free Polymer Solar Cells
(2014-02-26)
Mengistie, Desalegn A.
;
Ibrahem, Mohammed A.
;
Wang, Pen-Cheng
;
Chu, Chih-Wei
;
光電工程學系
We proposed a facile film treatment with formic acid to enhance the conductivity of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) by 4 orders of magnitude. The effect of formic acid concentration on conductivity was investigated; conductivity increased fast with increasing concentration up to 10 M and then increased slightly, the highest conductivity being 2050 S cm(-1) using 26 M concentration. Formic acid treated PEDOT:PSS films also exhibited very high transmittances. The mechanism of conductivity enhancement was explored through SEM, AFM, and XPS. Formic acid with its high dielectric constant screens the charge between PEDOT and PSS bringing about phase separation between them. Increased carrier concentration, removal of PSS from the film, morphology, and conformation change with elongated and better connected PEDOT chains are the main mechanisms of conductivity enhancement. ITO-free polymer solar cells were also fabricated using PEDOT:PSS electrodes treated with different concentrations of formic acid and showed equal performance to that of ITO electrodes. The concentrated acid treatment did not impair the desirable film properties as well as stability and performance of the solar cells.
BIOSENSOR ELECTRODE DEVICE AND METHOD FOR FABRICATING THE SAME
(2014-02-27)
LIN CHIN-TENG
;
LIAO LUN-DE
A biosensor electrode device and a method for fabricating the same are disclosed. The biosensor electrode device comprises a conductive substrate; at least one conductive spring, at least one probe, and an encapsulation member. Two ends of the conductive spring respectively connect with the conductive substrate and the probe. The probe moves close to or far away from the substrate through the elastic deformation of the conductive spring. The encapsulation member wraps the conductive substrate, the conductive springs and the probes but reveals a portion of each probe. The revealed probes contact skin of a testee for biomedical measurement. The device and method of the present invention can reduce the cost in mass-production. The biosensor electrode device will be a mainstream instrument in biomedical measurement.
STIMULI GENERATING METHODS, DEVICES AND CONTROL SYSTEMS TO INDUCE VISUAL EVOKED POTENTIALS USING IMPERCEPTIBLE FLICKERING MULTI-COLOR LIGHTS
(2014-02-27)
Zao John Kar-Kin
;
Huang Yi-Pai
;
Jung Tzyy-Ping
;
Lin Fang-Cheng
Visual or photic stimuli generating methods, devices and control systems for inducing steady-state visual evoked potential (SSVEP) from human viewers without causing discomfort to the viewers or distorting the embedding images are disclosed. The control system includes a stimuli-generating device and an electroencephalography (EEG) sensing device. The stimuli-generating device includes a first and a second light source. The first light source generates a flickering light with a first wavelength while a second light source generates another flickering light with one or more wavelength(s) differ from that of the first one. Together, the light sources generate visual/photic stimuli flickering above their critical flicker fusion threshold while maintaining the colorfulness and hue of the embedding images. At least one electrode of the EEG sensing device is connected to each viewer, configured to receive and analyze his/her EEG signals in order to detect and determine his/her responses to the stimuli.
Experimental and simulation analysis of concave-down resistance curve during electromigration in solder joints
(2014-02-28)
Lin, C. K.
;
Chang, Yuan Wei
;
Chen, Chih
;
材料科學與工程學系
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Department of Materials Science and Engineering
Resistance curves play a crucial role in detecting damage of solder joints during electromigration. In general, resistance increases slowly in the beginning, and then rises abruptly in the very late stage; i.e., the resistance curve behaves concave-up. However, several recent studies have reported concave-down resistance curves in solder joints with no satisfactory explanation for the discrepancy. In this study, electromigration failure mode in Sn2.5Ag solder joints was experimentally investigated. The bump resistance curve exhibited concave-down behavior due to formation of intermetallic compounds (IMCs). In contrast, the curve was concave-up when void formation dominated the failure mechanism. Finite element simulation was carried out to simulate resistance curves due to formation of IMCs and voids, respectively. The simulation results indicate that the main reason causing the concave-down curve is rapid formation of resistive Cu6Sn5 IMCs in the current-crowding region, which are 9 times larger than Cu IMCs. Therefore, when Cu reacted with Sn to form Cu6Sn5 IMCs, resistance increased abruptly, resulting in the concave-down resistance curve. (C) 2014 AIP Publishing LLC.
神經纖維分佈之分析方法及標準化誘發復合動作電位之量測方法
(2014-03-01)
蔡德明
一種神經纖維分佈之分析方法，係先令至少二電極作為訊號輸入端以將刺激訊號輸入神經組織，並透過電流調變技術調整作為訊號輸入端之至少二電極所輸入之刺激訊號之分配比率，以分別對神經組織中之複數個刺激範圍內之複數條神經纖維進行電刺激；再令至少一電極作為訊號接收端，以分別接收該複數個刺激範圍內之複數條神經纖維所響應出之複數個誘發複合動作電位；隨後對接收之複數個誘發複合動作電位進行整合比較，以分析出複數條神經纖維於神經組織中之分佈。另根據標準化誘發複合動作電位之量測方法及其應用來估計病患對於電刺激的最舒適電值(most comfortable level)和閾電值(threshold level)。
農作為方法：「以農為本」的抵抗政治
(國立陽明交通大學出版社, 2014-03-01)
蔡晏霖
VIBRATION ANALYSES OF CRACKED PLATES BY THE RITZ METHOD WITH MOVING LEAST-SQUARES INTERPOLATION FUNCTIONS
(2014-03-01)
Huang, C. S.
;
Chan, C. W.
;
土木工程學系
;
Department of Civil Engineering
The solutions for the vibrations of cracked thin plates are obtained by the Ritz method with admissible functions. Based on the classical plate theory, the basis functions comprising polynomials and crack functions are adopted to generate the admissible functions by the moving least-squares approach for a set of nodes randomly distributed in the domain. The crack functions account for the singular behaviors of stress resultants at crack tip(s), which are discontinuous in displacement and slope across the crack. The present solutions are validated through convergence tests of frequencies and by comparison with the published results for simply-supported cracked rectangular plates. The solutions are further employed to determine the natural frequencies of cantilevered skewed rhombic and isosceles triangular plates and completely free circular plates, each with a crack of varying length, location and orientation. The numerical results are tabulated and some corresponding mode shapes are also presented, by means of nodal patterns. Most of the results shown here are new to the literature.
現代性與台灣當代舞蹈映像：由迷戀「中國」到迷戀「福爾摩莎」
(國立陽明交通大學出版社, 2014-03-01)
盧玉珍
本文係針對前「新聞局」出版的《中國舞蹈》(1968)及《舞宴》(1995)兩部宣傳紀錄片，作音像比較與歷史分析，目的旨在釐清舞蹈如何再現官方政績，並試圖解讀兩部影片背後所扣連的台灣當代社會意識、現代性與族群身分政治的變遷等。紀錄片號稱是紀實電影，本身即為一種社會文本，記錄觀點更是檢驗拍攝當下的政治、社會指標。那麼在台灣特殊的時空下，舞蹈如何被動員來催化民族－國家的宣傳？從舞蹈紀錄片中，現代性在台灣的兩階段顯影，其所呈現的時代面貌、社會變遷與族群關係為何？當舞蹈成為官方宣傳主題時，即便是以正向方式來呈現「社會現實」，然而影片在模仿(mimesis)與敘事(diegesis)的框架之間，其兀自逸出的訊息是什麼？藉由「現代中國舞」(Modern Chinese Dance)與「原住民樂舞」的呈現方式，以及Agnes Heller的現代性邏輯分析，本研究發現，鏡頭在移轉之間所揭示的是，「黃昏的民族」意象與外省族群由權力位置移往邊緣的「同時共代」(Fabian, 1983)性，而促使台灣社會的族群關係躍然於銀幕之上者，其實是主體斷裂與扣連的能量，由迷戀符號「中國」轉向迷戀符號「福爾摩莎」的現代性追求。
Thermal stability and folding kinetics analysis of disordered protein, securin
(2014-03-01)
Chu, Hsueh-Liang
;
Chen, Tzu-Hsuan
;
Wu, Chang-You
;
Yang, Yao-Chen
;
Tseng, Shin-Hua
Lacking a stable tertiary structure, intrinsically disordered proteins (IDPs) possess particular functions in cell regulation, signaling, and controlling pathways. The study of their unique structural features, thermal stabilities, and folding kinetics is intriguing. In this study, an identified IDP, securin, was used as a model protein. By using a quasi-static five-step (on-path) folding process, the function of securin was restored and analyzed by isothermal titration calorimetry. Fluorescence spectroscopy and particle size analysis indicated that securin possessed a compact hydrophobic core and particle size. The glass transition of securin was characterized using differential scanning microcalorimetry. Furthermore, the folding/unfolding rates (k(obs)) of securin were undetectable, implying that the folding/unfolding rate is very fast and that the conformation of securin is sensitive to solvent environmental change. Therefore, securin may fold properly under specific physiological conditions. In summary, the thermal glass transition behavior and undetectable k(obs) of folding/unfolding reactions may be two of the indices of IDP.
Low-Power Multiport SRAM With Cross-Point Write Word-Lines, Shared Write Bit-Lines, and Shared Write Row-Access Transistors
(2014-03-01)
Wang, Dao-Ping
;
Lin, Hon-Jarn
;
Chuang, Ching-Te
;
Hwang, Wei
;
電子工程學系及電子研究所
This brief proposes one-write-one-read (1W1R) and two-write-two-read (2W2R) multiport (MP) SRAMs for register file applications in nanoscale CMOS technology. The cell features a cross-point Write word-line structure to mitigate Write Half-Select disturb and improve the static noise margin (SNM). The Write bit-lines (WBLs) and Write row-access transistors are shared with adjacent bit-cells to reduce the cell transistor count and area. The scheme halves the number of WBL, thus reducing WBL leakage and power consumption. In addition, column-based virtual VSS control is employed for the Read stack to reduce the Read power consumption. Post-sim results show that the proposed scheme reduces both Write/Read current consumption by over 30% compared with the previous MP structure. The proposed scheme is demonstrated and validated by an 8-Kb 2W2R SRAM test chip fabricated in TSMC 40-nm CMOS technology.
Sampling and conditioning artifacts of PM2.5 in filter-based samplers
(2014-03-01)
Liu, Chun-Nan
;
Lin, Sih-Fan
;
Awasthi, Amit
;
Tsai, Chuen-Jinn
;
Wu, Yueh-Chuen
Field studies were conducted at Taiwan National Chiao-Tung University (NCTU) campus to evaluate the evaporation loss of fine particles (PM2.5) collected by the multi-filter PM10-PM2.5 sampler (MFPPS), which was collocated with a dichotomous sampler (Dichot, Andersen, Model SA-241), a WINS PM2.5 sampler (Thermo, Model 2000-FRM), and a tapered element oscillating microbalance with the filter dynamic measurement system (TEOM-FDMS, Thermo, Model 1405-DF). Porous-metal denuder samplers (PDSs) were installed in sampling channels of the MFPPS to measure the concentration of evaporated ion species. Results showed that the evaporation loss in PM2.5 was severe during sampling, accounting for 5.8-36.0% of the corrected PM2.5 concentration and the percentage increased with decreasing loaded particle mass and increasing filtration velocity. During 24-h sampling, the evaporated NH4+, NO3- and Cl- concentrations accounted for 9.5 +/- 6.2, 5.4 +/- 3.7, and 2.0 +/- 1.3% in corrected PM(2.)5 concentration, respectively, or 46.4 +/- 19.2, 66.9 +/- 18.5, and 74.4 +/- 14.0% in the concentration of each species, respectively. Due to the evaporation loss, PM2.5 concentrations measured by the WINS, Dichot, and MFPPS were lower than those the TEOM-FDMS by 16.6 +/- 9.0, 15.2 +/- 10.6 and 12.5 +/- 8.8%, respectively. When the MFPPS PM(2.)5 concentrations were corrected for the evaporated loss determined by the PDS, good agreement with those by the TEOM-FDMS was achieved. (C) 2013 Elsevier Ltd. All rights reserved.
Iterative alpha-Glycosylation Strategy for 2-Deoxy- and 2,6-Dideoxysugars: Application to the One-Pot Synthesis of Deoxysugar-Containing Oligosaccharides
(2014-03-01)
Chen, Jiun-Han
;
Ruei, Jyh-Herng
;
Mong, Kwok-Kong Tony
;
應用化學系
;
Department of Applied Chemistry
This paper describes the development of an iterative and -selective glycosylation method for 2-deoxyglycosyl and 2,6-dideoxythioglycoside donors based on the DMF modulation concept. We used NMR spectroscopy to probe the 2-deoxyglycosyl imidinium intermediate and elucidated the conditions to decrease the formation of glycal and thus to increase the reaction yields. Further elaboration of the glycosylation method opened the gate for an iterative one-pot synthesis of 2-deoxy- and 2,6-dideoxyglycoside-containing oligosaccharides.
A molecular forensic method for identifying species composition of processed marine mammal meats
(2014-03-01)
Chang, Chia-Hao
;
Yao, Chiou-Ju
;
Yu, Hsin-Yi
;
Liao, Yun-Chih
;
Jang-Liaw, Nian-Hong
We used universal primers designed for the cytochrome oxidase I (CO I) sequence of the order Cetacea and the family Phocidae to prove that meat fritters sold in Taiwan contained meat from two seal, six cetacean, and one pig species. The sequence information for CO I obtained in this study was limited and population genetics data for the eight sampled marine mammalian species was insufficient to deduce where these marine mammals were hunted. Regardless of the geographic origins of the marine mammal flesh, sale and consumption of marine mammals in Taiwan violates the Wildlife Conservation Act. This study provides PCR primers that could enable government testing of suspect meats to curtail the illegal trade in marine mammal products. (C) 2014 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.