Browsing by Issue Date, starting with "2008-01-03"

Now showing 1 - 20 of 56361

Method of detecting for activating a temporal noise shaping process in coding audio signals
(2008-01-03)
Liu, Chi-min
;
Lee, Wen-chieh
;
Chang, Tzu-wen
A method of detecting for activating a temporal noise shaping process in coding audio signals comprises the steps of receiving continuous audio signals; computing a perceptual entropy value of each audio signal; comparing the perceptual entropy value with a threshold according to a discriminative condition; and activating temporal noise shaping process when a corresponding result is set true.
Apparatus, system and method for stream-based data filtering
(2008-01-03)
Lin, Po-Ching
;
Lin, Ying-Dar
;
Chen, Szu-Hao
;
Lai, Yuan-Cheng
An apparatus, a system and a method for stream-based data filtering are disclosed. The apparatus is for filtering data transmitted from a sending end. The data is transmitted one by one by using a plurality of data segments. The data filtering apparatus includes a receiving module, a processing module and a transmission module. The receiving module is for receiving the data segments transmitted from the sending end. The processing module implements virus scanning for the data segments one by one. The transmission module then transmits the data segments which have passed through the virus scanning to a receiving end.
Perceptual coding of audio signals by spectrum uncertainty
(2008-01-03)
Liu, Chi-min
;
Lee, Wen-chieh
;
Tin, Chiou
A method for digital encoding of an audio stream in which the psychoacoustic modeling bases its computations upon an MDCT for the intensity and a spectral flatness measurement that replaces the phase data for the unpredictability measurement. This dramatically reduces computational overhead while also providing an improvement in objectively measured quality of the encoder output. This also allows for determination of tonal attacks to compute masking effects.
GaN-based two-dimensional surface-emitting photonic crystal lasers with AlN/GaN distributed Bragg reflector
(2008-01-07)
Lu, Tien-Chang
;
Chen, Shih-Wei
;
Lin, Li-Fan
;
Kao, Tsung-Ting
;
Kao, Chih-Chiang
GaN-based two-dimensional (2D) surface-emitting photonic crystal (PC) lasers with AlN/GaN distributed Bragg reflectors are fabricated and demonstrated. The lasing threshold energy density is about 3.5 mJ/cm(2) per pulse under optical pumping at room temperature. Only one dominant emission wavelength of 424.3 nm with a narrow linewidth of 1.1 A above the threshold is observed. The laser emission covers whole circularly 2D PC patterns (50 mu m in diameter) with a small divergence angle. The lasing wavelength emitted from 2D PC lasers with different lattice constants occurs at the calculated band-edges provided by the PC patterns. The characteristics of large area, small divergence angle, and single mode emission from the GaN-based 2D surface-emitting PC lasers should be promising in high power blue-violet emitter applications.
Tungsten oxide/tungsten nanocrystals for nonvolatile memory devices
(2008-01-07)
Chen, C. H.
;
Chang, T. C.
;
Liao, I. H.
;
Xi, P. B.
;
Hsieh, Joe
In this work, the fabrication of WO(3)/W nanocrystals for nonvolatile memory devices has been achieved via rapid thermal oxidation of tungsten silicide. Amorphous Si and WSi(x) (x=2.7) layers were deposited onto the tunneling oxide and sequentially oxidized to form well-shaped WO(3)/W nanocrystals. The mean size of WO(3)/W nanocrystals is similar to 8.4 nm, while density is similar to 1.57x10(11) cm(-2). Moreover, the nonvolatile memory device for WO(3)/W nanocrystals exhibits similar to 0.53 V threshold voltage shift under 1 V/(-5 V) operation. The sample without capping a-Si layer was also fabricated for comparison. By material analyses, reasonable formation mechanisms are proposed in this letter. (C) 2008 American Institute of Physics.
Cost-effective wavelength-tunable fiber laser using self-seeding Fabry-Perot laser diode
(2008-01-07)
Yeh, Chien Hung
;
Shih, Fu Yuan
;
Wang, Chia Hsuan
;
Chow, Chi Wai
;
Chi, Sien
We propose and experimentally demonstrate a continuous wave (CW) tunable-wavelength fiber laser using self-seeding Fabry-Perot laser diode (FP-LD) without optical amplifier inside gain cavity. By employing a tunable bandpass filter (TBF) and a fiber reflected mirror (FRM) within a gain cavity, the fiber laser can lase a single-longitudinal wavelength due to the self-seeding operation. The proposed tunable wavelength laser has a good performance of the output power (> -15 dBm) and optical side-mode suppression ratio (> 40 dB) in the wavelength tuning range of 1533.75 to 1560.95 nm. In addition, the output stabilities of the fiber laser are also investigated. (c) 2007 Optical Society of America.
交大e-News第017期
(2008-01-07)
Secretariat
;
國立交通大學秘書室
Microprobe array structure and method for manufacturing the same
(2008-01-10)
Chiou, Jin-Chern
;
Chang, Chih-Wei
;
Hung, Chen-Chun
A microprobe array structure with self-stabilization capability and a method for manufacturing the same are proposed. The microprobe array structure is used to sense various biopotential signals, and is characterized in that the etching parameters are controlled during etching to manufacture a microprobe structure with a reduced bottom cross section so that the microprobe can be firmly stabilized in the skin tissue. Moreover, a conducting layer is formed on the microprobe to sense signals. A design of electric isolation between microprobes is also proposed. The microprobe array can therefore be used for the measurement of various biopotential signals, and can also be used as a stimulus.
多媒體簡訊樣板套用系統及播放系統、多媒體簡訊樣板套用方法及播放方法
(2008-01-11)
陳登吉
;
洪啟彰
;
楊博鈞
本發明係揭露一種多媒體簡訊樣板套用系統及播放系統、多媒體簡訊樣板套用方法及播放方法，該多媒體簡訊樣板套用系統包含多媒體物件、多媒體資料庫、樣板資料庫及套用單元。多媒體物件包含物件內容屬性及物件動作屬性，且物件動作屬性包含一互動功能；多媒體資料庫由多媒體資料所構成；樣板資料庫由簡訊樣板所構成，任一簡訊樣板包含多媒體物件之組合配置；套用單元根據使用者選擇，在樣板資料庫中找出對應之簡訊樣板，再根據使用者選擇，在多媒體資料庫中找出對應之多媒體資料，將其載入簡訊樣板所包含之多媒體物件之物件內容屬性，以建構一多媒體簡訊。
Submicron-scale manipulation of phase separation in organic solar cells
(2008-01-14)
Chen, Fang-Chung
;
Lin, Yi-Kai
;
Ko, Chu-Jung
;
光電工程學系
;
顯示科技研究所
This paper describes a method for controlling the submicron-scale phase separation of poly(3-hexylthiophene) and (6,6)-phenyl-C(61)-butyric acid methyl ester in organic solar cells. Using microcontact printing of self-assembled monolayers on the device buffer layer to divide the surface into two regimes having different surface energies, an interdigitated structure aligned vertical to the substrate surface is achieved after spontaneous surface-directed phase separation. The power conversion efficiency increases upon decreasing the grating spacing, reaching 2.47%. The hole mobility increased as a consequence of improved polymer chain ordering, resulting in higher device efficiency, while smaller pattern sizes were used. (c) 2008 American Institute of Physics.
Modeling of nitrogen profile effects on direct tunneling probability in ultrathin nitrided oxides
(2008-01-14)
Liu, Po-Tsun
;
Huang, Chen-Shuo
;
Lee, D. Y.
;
Lim, P. S.
;
Lin, S. W.
The dependence of the gate tunneling current (J(g)) on nitrogen profile (N profile) within an ultrathin silicon oxynitride film is reported. It was found that gate tunneling current is dependent on N profile, even with equal oxide thickness and nitrogen dosage. Gate tunneling current increased with steeper N profile, and it had higher sensitivity for p-type metal-oxide-semiconductor field-effect transistor (MOSFET) than n-type MOSFET. A direct tunneling model based on Wentzel-Kramers-Brillouin approximation has been proposed. The model described the influence of N profiles on gate tunneling current through local change of dielectric constant, band bending, and effective mass. Also, it reasonably explained the different J(g) sensitivity in n-/p-MOSFETs, a phenomenon that has not been addressed in earlier publications. (c) 2008 American Institute of Physics.
Microstructure and recording mechanism of Bi-Fe-(N) layer for high-density write-once optical disk
(2008-01-14)
Mai, Hung-Chuan
;
Hsieh, Tsung-Eong
;
Jeng, Shiang-Yao
;
Chen, Chong-Ming
;
Wang, Jen-Long
Bi-Fe-(N) thin film as the recording layer of high density digital versatile disk recordable optical disk was developed. For the disk sample with optimized layer structure, maximum partial response signal to noise ratio of 21.1 and minimum simulated bit error rate of 5x10(-7) were achieved at the write power=5.7 mW. Transmission electron microscopy characterization illustrated that the separation of Bi and Fe elements to form the coarse granular structure in the mark regime during laser irradiation comprised of the recording mechanism. (c) 2008 American Institute of Physics.
Improvement of luminescence from Si nanocrystals with thermal annealing in CO2
(2008-01-15)
Yang, M. D.
;
Chu, A. H. M.
;
Shen, J. L.
;
Huang, Y. H.
;
Yang, T. N.
Photoluminescence (PL) of Si nanocrystals with annealing in CO2 was studied using the continuous and time-resolved PL measurements. The PL intensity enhances as annealing temperature increases, which is attributed to passivation of the nonradiative recombination centers. As the annealing temperature is 950 degrees C the PL intensity has a maximum value, which increases about a factor of 3 than that of the untreated sample. Based on the emission energy dependence of the PL decay time, the depth of carrier localization is found to increase after the annealing in CO2. We suggest that the oxygen atoms desorbed from CO2 diffuse to react with Si nanocrystals and introduce localized states at the Si/SiO2 interface. (C) 2007 Elsevier B.V. All rights reserved.
管管作品兩首
(2008-01-15)
管管
Indoor sound field feature matching for robot's location and orientation detection
(2008-01-15)
Hu, Jwu-Sheng
;
Liu, Wei-Han
;
Cheng, Chieh-Cheng
;
電控工程研究所
;
Institute of Electrical and Control Engineering
In this work, an indoor sound field feature matching method is proposed and is applied to detect a mobile robot's location and orientation. The sound field feature, captured from a sound source to a pair of microphones, contains the dynamic of the propagation path. Because of the complexity of indoor environment, the features from different path can be distinguished using appropriate models. Gaussian mixture models are utilized in this paper to characterize the phase difference and magnitude ratio distributions between the microphone pair in consecutive data frames. The application provides an alternative thinking compared with traditional methods such as direction of arrival (DOA) using propagation delay. They usually suffer from reverberation, non-line-of-sight and microphone mismatch problems. The experimental results show the method not only has a high recognition rate for robot's location and orientation, but also is robust against environmental noise. (c) 2007 Elsevier B.V. All rights reserved.
Active 433 MHz-W UHF RF-powered chip integrated with a nanocomposite m-MWCNT/polypyrrole sensor for wireless monitoring of volatile anesthetic agent sevoflurane
(2008-01-15)
Chavali, Murthy
;
Lin, Tzu-Hsuan
;
Wu, Ren-Jang
;
Luk, Hsiang-Ning
;
Hung, Shih-Lin
Tiny remote sensors capable of monitoring gases and vapors are having greatest demand due to their potential applications in diverse research fields. In the present work, design and fabrication of an active wireless UHF (433 MHz) RF-powered sensing system for monitoring volatile organic compounds is presented. The developed sensor chip consists of a thin film of gas-responsive composite material, based on modified multiwalled carbon nanotubes (m-MWCNTs) and polypyrrole (Ppy), coated over two comb-like interdigitated gold electrodes. Wireless modules have been integrated with the chemical sensor chip (composite m-MWCNTs/Ppy) and RF components to detect volatile anesthetic agent, fluoromethyl 2,2,2,-trifluoro-1-(trifluoromethyl) ethyl ether (sevoflurane) is demonstrated. (c) 2007 Elsevier B.V. All rights reserved.
管管作品兩首
(2008-01-15)
管管
Novel reactive compatibilization strategy on immiscible polypropylene and polystyrene blend
(2008-01-15)
Hung, Chen-Jui
;
Chuang, Hung-Yang
;
Chang, Feng-Chih
;
應用化學系
;
Department of Applied Chemistry
Polypropylene (PP) and polystyrene (PS) are immiscible and incompatible. Since both PP and PS components possess no reactive functional group, reactive compatibilization of a PP/PS blend is impossible unless certain reactive functional groups are imparted to either PP or PS. In this study we provide a simple approach to reactively compatibilize the nonreactive PP/PS blend system by physically functionalizing PP and PS with the addition of maleic anhydride grafted PP (PP-g-MA) and styrene maleic anhydride random copolymer (SMA), respectively. An epoxy monomer, serving as a coupler and possessing four epoxy groups able to react with the maleic anhydride of PP-g-MA and SMA, was then added during melt blending. Observations of the finer PS domain sizes and improved mechanical properties support the plausibility of reactive compatibilization of this nonreactive PP/PS blend by combining physically functionalized PP and PS with tetra-glycidyl ether of diphenyl dian-Lino methane (TGDDM) in a one-step extrusion process. (C) 2007 Wiley Periodicals, Inc.
管管作品兩首
(2008-01-15)
管管
管管作品兩首
(2008-01-15)
管管