Browsing by Issue Date, starting with "2010-08-15"

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Tonic and phasic EEG and behavioral changes induced by arousing feedback
(2010-08-15)
Lin, Chin-Teng
;
Huang, Kuan-Chih
;
Chao, Chih-Feng
;
Chen, Jian-Ann
;
Chiu, Tzai-Wen
This study investigates brain dynamics and behavioral changes in response to arousing auditory signals presented to individuals experiencing momentary cognitive lapses during a sustained-attention task. Electroencephalographic (EEG) and behavioral data were simultaneously collected during virtual-reality (VR) based driving experiments, in which subjects were instructed to maintain their cruising position and compensate for randomly induced lane deviations using the steering wheel. 30-channel EEG data were analyzed by independent component analysis and the short-time Fourier transform. Across subjects and sessions, intermittent performance during drowsiness was accompanied by characteristic spectral augmentation or suppression in the alpha- and theta-band spectra of a bilateral occipital component, corresponding to brief periods of normal (wakeful) and hypnagogic (sleeping) awareness and behavior. Arousing auditory feedback was delivered to the subjects in half of the non-responded lane-deviation events, which immediately agitated subject's responses to the events. The improved behavioral performance was accompanied by concurrent spectral suppression in the theta- and alpha-bands of the bilateral occipital component. The effects of auditory feedback on spectral changes lasted 30 s or longer. The results of this study demonstrate the amount of cognitive state information that can be extracted from noninvasively recorded EEG data and the feasibility of online assessment and rectification of brain networks exhibiting characteristic dynamic patterns in response to momentary cognitive challenges. (C) 2010 Elsevier Inc. All rights reserved.
Ultra-High Data-Rate 60 GHz Radio-Over-Fiber Systems Employing Optical Frequency Multiplication and OFDM Formats
(2010-08-15)
Lin, Chun-Ting
;
Chen, Jyehong
;
Shih, Po-Tsung
;
Jiang, Wen-Jr
;
Chi, Sien
The increasing demand for wireless video-based interactive and multimedia data services explains why 60-GHz millimeter-wave wireless system is a promising candidate to provide multi-gigabit-per-second wireless services. While attempting to generate and transmit 60 GHz signals in a wireless system cost effectively and increase the spectral efficiency to facilitate multi-gigabit-per-second services, this work reviews three radio-over-fiber (RoF) systems based on optical frequency multiplication (up to 6 times) to reduce the bandwidth requirement of optical transmitters. Additionally, orthogonal frequency division multiplexing (OFDM) signals with multi-level modulation formats (16 QAM) are utilized to achieve an ultrahigh data rate of 28 Gbps within the 7-GHz license-free band and compensate for an uneven frequency response of 60-GHz RoF systems. Negligible power penalty following 25-km standard single mode fiber (SSMF) transmission is observed, capable of significantly extending the service range to various applications within a building or campus.
Extracting photon periodic orbits from spontaneous emission spectra in laterally confined vertically emitted cavities
(2010-08-15)
Chen, Yung-Fu
;
Yu, Yan-Ting
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Huang, Yu-Jen
;
Chiang, Po-Yi
;
Su, Kuan-Wei
We report our observation of the signature of photon periodic orbits in the spontaneous emission spectra of large-aperture vertical-cavity surface-emitting lasers (VCSELs). The high-resolution measurement clearly demonstrates that over a thousand cavity modes with a narrow linewidth can be perfectly exhibited in the spontaneous emission spectrum just below the lasing threshold. The Fourier-transformed spectrum is analyzed to confirm that the spontaneous emission spectra of large-aperture VCSELs can be exploited to analogously investigate the energy spectra of the 2D quantum billiards. (C) 2010 Optical Society of America
Label-free detection of DNA using novel organic-based electrolyte-insulator-semiconductor
(2010-08-15)
Lin, Tsung-Wu
;
Kekuda, Dhananjay
;
Chu, Chih-Wei
;
光電工程學系
;
Department of Photonics
In this study, we have constructed the first organic field effect sensor based on an electrolyte-insulator-semiconductor structure (OEIS) and applied this novel device to pH and DNA sensing. Variations in the insulator-electrolyte surface potential, which originate from either the change of the ionization states of the insulator surface groups or the binding of charged molecules to the insulator surface, modify the flat band voltage (V(FB)) of the OEIS sensor. The pH sensing experiments of OEIS sensor showed that the output signal linearly depended on pH solution in the range from pH 2 to pH 12, and an average sensitivity of 44.1 mV/pH was obtained. In the biosensing experiments, the absorption of positively charged poly-L-lysine on the insulator surface resulted in the reduction of the V(FB) value, whereas the subsequent binding of negatively charged single-stranded DNA probe (ssDNA) via electrostatic interaction increased the VFB value. Furthermore, the ssDNA-immobilized OEIS device was successfully used for the detection of DNA hybridization. The detection limit of complementary DNA was as low as 1 mu M, and the output signal of OEIS biosensor linearly increased with the logarithm of complementary DNA concentration in the range from 5 x 10(-5) to 10(-7) M. The easy and inexpensive fabrication of the OEIS device allows to be served as a potentially disposable and sensitive biosensor. (C) 2010 Elsevier B.V. All rights reserved.
Imaging brain hemodynamic changes during rat forepaw electrical stimulation using functional photoacoustic microscopy
(2010-08-15)
Liao, Lun-De
;
Li, Meng-Lin
;
Lai, Hsin-Yi
;
Shih, Yen-Yu I.
;
Lo, Yu-Chun
The present study reported the development of a novel functional photoacoustic microscopy (fPAM) system for investigating hemodynamic changes in rat cortical vessels associated with electrical forepaw stimulation. Imaging of blood optical absorption by fPAM at multiple appropriately-selected and distinct wavelengths can be used to probe changes in total hemoglobin concentration (HbT, i.e., cerebral blood volume [CBV]) and hemoglobin oxygen saturation (SO(2)). Changes in CBV were measured by images acquired at a wavelength of 570 nm (lambda(570)), an isosbestic point of the molar extinction spectra of oxy- and deoxy-hemoglobin, whereas SO(2) changes were sensed by pixel-wise normalization of images acquired at lambda(560) or lambda(600) to those at lambda(570). We demonstrated the capacity of the fPAM system to image and quantify significant contralateral changes in both SO(2) and CBV driven by electrical forepaw stimulation. The fPAM system complements existing imaging techniques, with the potential to serve as a favorable tool for explicitly studying brain hemodynamics in animal models. (C) 2010 Elsevier Inc. All rights reserved.
Simple 14-Gb/s Short-Range Radio-Over-Fiber System Employing a Single-Electrode MZM for 60-GHz Wireless Applications
(2010-08-15)
Jiang, Wen-Jr
;
Lin, Chun-Ting
;
Ng'oma, Anthony
;
Shih, Po-Tsung
;
Chen, Jason Jyehong
This paper demonstrates the feasibility of a simple multigigabit-per-second (Gbps) radio-over-fiber (RoF) system employing multilevel orthogonal frequency-division-multiplexing (OFDM) signal modulation at 60 GHz and a single-electrode Mach-Zehnder modulator (MZM). In this paper, the impact of fiber chromatic dispersion and OFDM beat noise on the performance of the RoF system are investigated by theoretical analysis, VPI WDM-TransmissionMaker simulation and experimental demonstration. A 13.875-Gb/s QPSK OFDM signal occupying the full 7-GHz license-free band at 60 GHz with frequency multiplication for the RoF link is demonstrated. After 3 km of standard single-mode fiber transmission with no dispersion compensation, the power penalty is less than 3 dB.
Inactivation of E. coli and B. subtilis by a parallel-plate dielectric barrier discharge jet
(2010-08-15)
Chiang, M. H.
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Wu, J. Y.
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Li, Y. H.
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Wu, J. S.
;
Chen, S. H.
Inactivation of Escherichia coli and Bacillus subtilis using the jet region of a parallel-plate air dielectric barrier discharge (DBD) driven by a distorted sinusoidal voltage power supply under atmospheric-pressure condition is reported. Various types of working gases, including pure N(2), pure O(2), and compressed air, were tested. Discharges were characterized electrically by measuring the discharge current, applied voltage and absorbed power, and optically by measuring the optical emission spectra in the UV-visible range and absorption spectra in the IR range. Results of survival rate show that both E. coil and B. subtilis cells (up to 10(7) CFU/mL) can be effectively inactivated using less than 18 passes (1.8 s of residence time in total) of exposure to the post-discharge jet region of compressed air and oxygen discharges at different treating distances in the range of 4-20 mm. Among these, the compressed-air discharge performs the best in inactivating both two types of the bacterial cells, because of the abundant ozone generation and probably through the assistance of nitrous oxide generated in the discharge. In summary, the post-discharge jet region of an oxygen-contained parallel-plate DBD driven by a distorted sinusoidal voltage power driven is very effective in inactivating both E. coli and B. subtilis cells under the present test conditions. Crown Copyright (c) 2010 Published by Elsevier B.V. All rights reserved.
Theory and Technology for Standard WiMAX Over Fiber in High Speed Train Systems
(2010-08-15)
Yeh, Chien-Hung
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Chow, Chi-Wai
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Liu, Yen-Liang
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Wen, Sz-Kai
;
Chen, Shi-Yang
In this investigation, we propose and investigate the standard WiMAX access in high speed railway (HSR) using radio over fiber (RoF) link. We also discuss the theory of mobile WiMAX at a target speed of 300 km/hr in simulation. We also analyze the effect of the Doppler frequency shift over HSR. The effective transmission fiber length in the WiMAX-RoF system was limited due to the time-division-duplex (TDD) protocol in the practical WiMAX. Thus, we also demonstrate the transmission limitation and performance of the standard WiMAX access in RoF link. The performances of throughput and packet loss at different fiber lengths are also investigated and discussed. Furthermore, a WiMAX-RoF field trial is also demonstrated based on a simple two RAUs RoF architecture. It was tested and measured in the SongShan tunnel of the Taiwan high speed railway (THSR).
具有非極性三族－氮化物層的多層結構及其製法
(2010-08-16)
李威儀
;
陳振芳
;
江振豪
一種具有非極性三族-氮化物層的多層結構及其製法,包括在基板上形成複數成核層;以及於該成核層上形成非極性三族-氮化物層,其中,各該複數成核層係獨立選自下式(I)之氮化物:AxB1-xN (I) 式中,A和B係選自B、Al、Ga、IN或Tl之不相同的元素,且0≦x≦1。該複數成核層可有效減緩應力、減少晶格位差、阻擋差排延伸並降低差排密度,故可形成表面平坦且結晶品質佳之三族-氮化物層。
三維微結構之組裝方法
(2010-08-16)
邱一
;
黃煒智
;
吳昌修
本發明揭示一種只需一推即可完成組裝的三維微結構之組裝方法，包括提供具有下凹的一容置空間的基底層，在基底層上設置具有一組裝推墊及至少一旋轉軸的豎立元件，在豎立元件上設置固定裝置，此固定裝置包括至少一鉸鏈固定元件，橫置於旋轉軸上。最後，推動組裝推墊使旋轉軸旋轉，至組裝推墊完全沒入容置空間，豎立元件即完成豎立，本發明並提出一種似V懸臂之鉸鏈固定元件使旋轉軸旋轉時上下左右均不會晃動。本發明與電子封裝製程相容，因此組裝便於自動化，特別若有多個微結構陣列設置，亦可以自動化設備同時推動多個組裝推墊以完成組裝。
保護軟體內容之嵌入式保護裝置及其保護方法
(2010-08-16)
林進燈
;
吳孟哲
;
鍾仁峰
;
沈子貴
;
洪紹航
本發明係揭露一種保護軟體內容之嵌入式保護裝置及其保護方法，其係在一處理器執行嵌入式軟體，即韌體程式時執行授權檢查，此嵌入式保護裝置可接收韌體程式執行時所傳送之授權碼，藉以在內部連續產生一虛擬隨機亂數，之後再利用此亂數產生公、私鑰，對授權碼加密，並形成一加密資料，之後更可對此加密資料進行解密，並將結果傳回執行的處理器，以判斷是否可進行授權。若是，則執行此韌體程式，且重複上述的加密動作；若否，則無法執行此韌體程式。本發明係利用硬體執行加解密動作，進而使嵌入式韌體受到更好的安全保護機制。
Continuous wave operation of current injected GaN vertical cavity surface emitting lasers at room temperature
(2010-08-16)
Lu, Tien-Chang
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Chen, Shih-Wei
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Wu, Tzeng-Tsong
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Tu, Po-Min
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Chen, Chien-Kang
We report the demonstration of the continuous wave laser action on GaN-based vertical cavity surface emitting lasers at room temperature. The laser structure consists of a ten-pair Ta(2)O(5)/SiO(2) distributed Bragg reflector (DBR), a 7 lambda-thick optical cavity, ten-pairs InGaN/GaN multiquantum wells with an AlGaN electron blocking layer, and a 29-pair AlN/GaN DBR. The laser has a threshold current of about 9.7 mA corresponding to the current density of about 12.4 kA/cm(2) and a turn-on voltage about 4.3 V at 300 K. The lasing wavelength was 412 nm with a linewidth of about 0.5 nm. A spontaneous emission coupling efficiency factor of about 5x10(-3) and the degree of polarization of about 55% were measured, respectively. The laser beam has a narrow divergence angle of about 8 degrees. (C) 2010 American Institute of Physics. [doi:10.1063/1.3483133]
串流影音資料傳輸控制方法及其架構
(2010-08-16)
黃經堯
;
陳志展
;
李純孝
本發明提供一種串流影音資料傳輸控制方法及其架構,其利用傳輸端一回報傳輸速率改善接收端播放延遲的情況。回報傳輸速率係依據前週期傳輸暫存器之資料剩餘量以及實際傳輸速率而定。而實際傳輸速率則為需求傳輸速率與可用傳輸速率之較小者,其中需求傳輸速率係依據資料剩餘量及回報傳輸速率決定。因此,回報傳輸速率可隨著資料剩餘量的累積而調整,有效改善發生播放延遲的情況。
Suppression of Octahedral Tilts and Associated Changes in Electronic Properties at Epitaxial Oxide Heterostructure Interfaces
(2010-08-19)
Borisevich, A. Y.
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Chang, H. J.
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Huijben, M.
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Oxley, M. P.
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Okamoto, S.
Epitaxial oxide interfaces with broken translational symmetry have emerged as a central paradigm behind the novel behaviors of oxide superlattices. Here, we use scanning transmission electron microscopy to demonstrate a direct, quantitative unit-cell-by-unit-cell mapping of lattice parameters and oxygen octahedral rotations across the BiFeO(3)-La(0.7)Sr(0.3)MnO(3) interface to elucidate how the change of crystal symmetry is accommodated. Combined with low-loss electron energy loss spectroscopy imaging, we demonstrate a mesoscopic antiferrodistortive phase transition near the interface in BiFeO(3) and elucidate associated changes in electronic properties in a thin layer directly adjacent to the interface.
Self-assembly of an A-B diblock copolymer blended with a C homopolymer and a C-D diblock copolymer through hydrogen bonding interaction
(2010-08-19)
Chen, Wan-Chun
;
Kuo, Shiao-Wei
;
Chang, Feng-Chih
;
應用化學系
;
Department of Applied Chemistry
In this study, we investigated the miscibility, phase behavior, and self-assembled nanostructures formed from the immiscible crystalline-amorphous diblock copolymer poly(epsilon-caprolactone-b-4-vinyl pyridine) (PCL-b-P4VP, A-B) when blended with the homopolymer poly(vinyl phenol) (PVPh, C) and the diblock copolymer poly(vinyl phenol-b-styrene) (PVPh-b-PS, C-D). Long-range-ordered microphase separation was difficult to achieve in the PCL-b-P4VP/PVPh (A-B/C) blend system because PVPh interacted with both the P4VP and PCL blocks simultaneously through hydrogen bonding interactions. In contrast, we observed sharp, multiple orders of diffraction in the SAXS profiles of the PCL-b-P4VP/PVPh-b-PS (A-B/C D) blend system, indicating that perfect microphase separation occurred because the incorporation of the PS block induced the PVPh block to hydrogen bond preferentially with the P4VP block. This simple A-B/C-D (PCL-b-P4VP/PVPh-b-PS) diblock copolymer mixture exhibited self-assembly behavior (a three-lamella phase) similar to that of a corresponding ABC triblock copolymer. (C) 2010 Elsevier Ltd. All rights reserved.
Effects of sputtering pressure and Al buffer layer thickness on properties of AZO films grown by rf magnetron sputtering
(2010-08-20)
Tseng, C. H.
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Wang, W. H.
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Chang, H. C.
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Chou, C. P.
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Hsu, C. Y.
Transparent and conductive Al-doped (2 wt.%) zinc oxide (AZO) films were deposited on inexpensive soda-lime glass substrates by using rf magnetron sputtering at room temperature. This study analyzed the effects of argon sputtering pressure, which varied in the range from 0.46 to 2.0 Pa, on the morphological, electrical and optical properties of AZO films. The only (0 0 2) diffraction peak of the film were observed at 20 similar to 34.45 degrees, exhibiting that the AZO films had hexagonal ZnO wurtzite structure, and a preferred orientation with the c-axis perpendicular to the substrate. By applying a very thin aluminum buffer layer with the thickness of 2 nm, findings show that the electrical resistivity was 9.46 x 10(-4) Omega-cm, and the average optical transmittance in the visible part of the spectra was approximately 81%. Furthermore, as for 10 nm thick buffer layer, the electrical resistivity was lower, but the transmittance was decreased. (C) 2010 Elsevier Ltd. All rights reserved.
資料搜尋方法及其數值資料編碼方法
(2010-08-21)
鄭哲聖
;
單智君
;
鍾崇斌
本發明係揭露一種資料搜尋方法及其數值資料編碼方法，此方法將已排序之複數個數值分成複數個群組，每一群組之第一個數值係代表為跳躍點，而其他數值係代表為內部點，接著，使用一第一編碼演譯程序對該些群組之跳躍點進行編碼，以產生複數個跳躍點編碼值，並使用一空間預估程序，預估此些內部點以一第二編碼演譯程序進行編碼時所需之位元保留空間，繼之，根據該第二編碼演譯程序對該些群組之該些內部點進行編碼，以產生複數個內部點編碼值。最後，根據群組之排列順序及位元保留空間，將跳躍點編碼值及內部點編碼值依序排列，以產生一輸出編碼資料。
消除正交分頻多工系統中因通道時變產生載波間干擾的方法
(2010-08-21)
吳文榕
;
許兆元
正交分頻多工(OFDM)系統於高速移動的環境下，通道在一OFDM符元(symbol)內具有時變特性，此時變特性會造成載波間正交性喪失而互相干擾，降低系統效能，因此本發明即在提供一種消除正交分頻多工系統中因通道時變產生載波間干擾的方法，其係利用線性時變通道之干擾矩陣本身的特殊結構，配合牛頓疊代(iteration)法化簡反矩陣運算，並使用快速傅立葉轉換降低運算量，不需使用額外電路即可達到消除載波間干擾之目的。
Solid-phase thermodynamic interpretation of ion desorption in matrix-assisted laser desorption/ionization
(2010-08-22)
Lai, Yin Hung
;
Wang, Chia Chen
;
Lin, Sheng Hsian
;
Wang, Yi Sheng
;
Lee, Yuan Tseh
交大e-News第077期
(2010-08-23)
Secretariat
;
國立交通大學秘書室