Browsing by Issue Date, starting with "2012-02-13"

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Selecting detection wavelength of resonant cavity-enhanced photodetectors by guided-mode resonance reflectors
(2012-02-13)
Lai, Kuo-Wei
;
Lee, Yi-Shan
;
Fu, Ying-Jhe
;
Lin, Sheng-Di
;
電子工程學系及電子研究所
We propose and demonstrate a novel device structure of resonant cavity-enhanced photodetector (RCE-PD). The new RCE-PD structure consists of a bottom distributed Bragg reflector (DBR), a cavity with InGaAs multiple quantum wells (MQWs) for light absorption and a top mirror of sub-wavelength grating. By changing the fill factor of the 2-D grating, the effective cavity length of RCE-PDs can be varied so the resonant wavelength can be selected post growth. Accordingly, we can fabricate an array of PDs on a single chip, on which every PD aims for a specific wavelength. (C) 2012 Optical Society of America
Temperature-dependent decay dynamics in highly mismatched ZnSe1-xTex alloy
(2012-02-13)
Lin, Yan-Cheng
;
Jiang, Wei-Shi
;
Chou, Wu-Ching
;
Chen, Wei-Kuo
;
Chang, Wen-Hao
This study investigates the temperature-dependent decay dynamics in highly mismatched ZnSe0.950Te0.050 alloy using photoluminescence (PL) and time-resolved PL spectroscopy. The PL peak energy exhibits a V-shaped dependence on temperature (10-300 K), indicating strong carrier localization. Kohlrausch's stretched exponential law, in which the deduced stretching exponent beta is highly consistent with the V-shaped PL peak shift, closely corresponds to the complex decay curves over a wide temperature range. Additionally, the PL lifetime tau initially increases and then monotonically declines as the temperature increases. These findings agree excellently with the low electron-hole binding energy upon thermal ionization of weakly bound electrons. (C) 2012 American Institute of Physics. [doi:10.1063/1.3687187]
Low threshold current and widely tunable external cavity lasers with chirped multilayer InAs/InGaAs/GaAs quantum-dot structure
(2012-02-13)
Lin, Gray
;
Su, Pei-Yin
;
Cheng, Hsu-Chieh
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Low threshold and widely tunable InAs/GaAs quantum-dot lasers are implemented with grating-coupled external-cavity arrangement. Throughout the tuning range of 130 nm, from 1160 to 1290 nm, the threshold current density is not more than 0.9 kA/cm(2) and no noticeable threshold jump is observed. For a shorter-cavity device, the injection current is kept at a record low value of 90 mA but the tuning range is further extended to 150 nm, from 1143 to 1293 nm. The effect of cavity length on the tuning characteristics is discussed and the strategy for design and optimization of multilayer quantum-dot structure is also proposed. (C) 2012 Optical Society of America
Design of distributed amplify-and-forward relay networks for multi-input multi-output transmission
(2012-02-14)
Wu, C-J
;
Lin, D. W.
;
Sang, T-H
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Relays can potentially enhance the transmission performance of multi-input multi-output (MIMO) systems. A parallel single-antenna relay network has additional advantages in flexibility, diversity and cost, but also poses significant design problems because the absence of inter-antenna connections over different relays makes the underlying mathematical problems much more difficult to solve. In this study, the authors consider the design of parallel amplify-and-forward relay networks. More specifically, the authors consider the design of relay gains to maximise the system capacity. As no closed-form analytic solution can be found, the authors first develop an iterative algorithm to find a locally optimal solution. Since algorithmic optimisation provides little insight into the analytical properties of the solution, they also attempt analytical solutions for several asymptotic noise conditions. It turns out that the solutions involve some methods to select the optimal subsets of relays for signal forwarding. The authors analyse the resulting capacity outage diversity orders and confirm the analysis with simulation results.
Method for identification of traffic lane boundary
(2012-02-14)
Jou Yow-Jen
;
Cho Hsun-Jung
;
Chen Yu-Kuang
;
Huang Heng
;
Hsu Chia-Chun
The invention provides a method for identification of traffic lane boundary. Firstly the microwave signal is received, and the noise reduction is treated for the microwave signal. Then the frequency domain information is employed to calculate the legal set of closed interval, in order to form the frequency span information. Finally, the probability density function model is employed to calculate the frequency span information in order to identify the traffic lane boundary.
PHPIT and fabrication thereof
(2012-02-14)
Wei Kung-Hwa
;
Chang Yao-Te
The present invention provides PHPIT and fabrication thereof. PHPIT has a side-chain-tethered with hexylphenanthrenyl-imidazole polythiophene. The visible light absorption of the PHPIT/PCBM blend is enhanced by the presence of the electron-withdrawing hexylphenanthrenyl-imidazole. The PHPIT/PCBM blend experienced more-balanced electron and hole mobilities and solvability.
Universal conductance fluctuations in indium tin oxide nanowires
(2012-02-14)
Yang, Ping-Yu
;
Wang, L. Y.
;
Hsu, Yao-Wen
;
Lin, Juhn-Jong
;
電子物理學系
Magnetic-field-dependent universal conductance fluctuations (UCFs) are observed in weakly disordered indium tin oxide nanowires from 0.26 K up to similar to 25 K. The fluctuation magnitudes increase with decreasing temperature, reaching a fraction of e(2)/h at T less than or similar to 1 K. The shape of the UCF patterns is found to be very sensitive to thermal cycling of the sample to room temperature, which induces irreversible impurity reconfigurations. On the other hand, the UCF magnitudes are insensitive to thermal cycling. Our measured temperature dependence of the root-mean-square UCF magnitudes is compared with the existing theory [C. W. J. Beenakker and H. van Houten, Phys. Rev. B 37, 6544 (1988)]. A notable discrepancy is found, which seems to imply that the experimental UCFs are not cut off by the thermal diffusion length L-T, as would be expected by the theoretical prediction when L-T < L-phi, where L-phi is the electron dephasing length. The approximate electron dephasing length is inferred from the UCF magnitudes and compared with that extracted from the weak-localization magnetoresistance studies. A reasonable semiquantitative agreement is observed.
Collinear holographic storage method and apparatus
(2012-02-14)
Sun Ching-Cherng
;
Yu Yeh-Wei
In the specification and drawings, a collinear holographic storage method is described and shown with a controlling step to control the temperature of the collinear holographic storage media such that the writing temperature of the collinear holographic storage media is from between about 5° C. to about 50° C. higher than the reading temperature of the collinear holographic storage media.
Print dipole antenna and manufacturing method thereof
(2012-02-14)
Cheng Li-Yuan
;
Chen Fu-Chiarng
The present invention discloses a print dipole antenna and manufacturing method thereof. The print dipole antenna has a plurality of resonance frequencies, which comprises a substrate, a ring microstrip line and a ground plane. The ring microstrip line is disposed on one side of the substrate, and the interior of the ring microstrip line is symmetrically disposed with a plurality of parasitic metals. The ground plane is disposed on the other side of the substrate, and has a hollow portion corresponding to the central area of the ring microstrip line. The ring microstrip line has a plurality of end ports including input end ports and output end ports, which may further comprise an open circuit end. The plurality of parasitic metals may be of linear shape or bended in arbitrarily windings. A normal mode signal is fed from the end points of the plurality of parasitic metals.
Automatic ultrasonic and computer-vision navigation device and method using the same
(2012-02-14)
Wu Chih-Jen
;
Tsai Shung-Yung
;
Tsai Wen-Hsiang
The present invention discloses an automatic ultrasonic and computer-vision navigation device and a method using the same. In the method of the present invention, the user guides an automatic navigation device to learn and plan a navigation path; next, the automatic navigation device navigates independently and uses ultrasonic signals and computer vision to detect the environment; then, the automatic navigation device compares the detected environment data with the navigation path to amend the physical movement track. The present invention enables ordinary persons to interact with the automatic navigation device without operating the computer. As the present invention adopts computer vision and ultrasonic signals to realize the functions thereof, the manufacturers can save the hardware cost.
Aqueous zymography screening of matrix metalloproteinase activity and inhibition based on colorimetric gold nanoparticles
(2012-02-15)
Chuang, Yao-Chen
;
Huang, Wei-Ting
;
Chiang, Pin-Hsuan
;
Tang, Meng-Che
;
Lin, Chih-Sheng
An optical gold nanoparticles (AuNPs)-based method was fabricated for the rapid detection of matrix metalloproteinase (MMP) activity and screening potential MMP inhibitors without sophisticated instruments. The diagnosis platform was composed of AuNPs, particular MMP substrates and 6-mercapto-1-hexanol (MCH). The functionalized AuNPs were subjected to specific MMP digestion, and the MMP found the substrate on AuNPs, such that the AuNPs lost shelter and MCH increased the attraction force between AuNPs. Consequently, AuNPs aggregation and a color change from red to purple with increasing MMP concentration were observed. The surface plasmon resonance (SPR) of the formed AuNPs allowed for the quantitative detection of MMP activity. A sensitive linear correlation existed between the absorbance and the activity of the MMPs, which ranged from 10 ng/mL to 700 ng/mL in NTTC buffer and plasma samples. The proposed colorimetric method could be accomplished in a homogeneous solution with one-step operation in 30 min and has been successfully applied to the determination of particular MMP activity in plasma samples, in which the results are consistent with substrate zymography. This technology may become a simple platform for parallel screening a number of inhibitors and offer an alternative method to studying the efficiency of inhibitors for suppressing MMP activity. The absorbance ratio at 625 nm and 525 nm (A(625)/A(525)) confirmed the efficiency of the inhibitors as observed in substrate zymography. The IC50 of ONO-4817 and galardin for MMP-1, MMP-2 and MMP-7 determined by the proposed colorimetric method was similar to the results of substrate zymography. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.
Expert system based parallel multi-1D block matching algorithm with implementation for motion estimation
(2012-02-15)
Lin, Shin-Yeu
;
Su, Chong-Wei
;
Huang, Jung-Shou
;
電控工程研究所
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Institute of Electrical and Control Engineering
In this paper, we propose an expert-system based parallel multi-1-dimensional block matching algorithm (ESPM-1D-BMA) for motion estimation (ME). Instead of the conventional 2D block matching, we employ the parallel multi-1D blocks matching to improve the computing speed. To improve the ME accuracy, we design a knowledge base and inference engine to determine the true motion vector (MV) from the results of parallel multi-1D blocks matching. To speed up the computing speed further, we present a hardware architecture for implementing the ESPM-1D-BMA. We have demonstrated that the MV estimation accuracy achieved by the proposed ESPM-1D-BMA is much better than the comparing fast block matching algorithms and is close to the 2 dimensional full search block matching algorithm (2D-FSBMA). We also demonstrate that the computing speed of the proposed ESPM-1D-BMA is about two times as fast as the mixed-signal 2D-FSBMA (MS-2D-FSBMA). (C) 2011 Elsevier Ltd. All rights reserved.
Photonic crystal horizontally slotted nanobeam cavity for silicon-based nanolasers
(2012-02-15)
Lu, Tsan-Wen
;
Lin, Pin-Tso
;
Lee, Po-Tsung
;
光電工程學系
;
Department of Photonics
We theoretically propose and investigate a TM-polarized one-dimensional photonic crystal nanocavity with a horizontal SiO2 slot on a suspended silicon nanobeam via the three-dimensional finite-element method. The ultrahigh quality factor and ultrasmall effective mode volume of 1.5 x 10(7) and 0.176 half-wavelength cubic of the horizontally SiO2-slotted nanocavity show strong possibilities for realizing an erbium-doped SiO2 nanolaser. This horizontal SiO2 slot structure can be precisely formed via the sputtering process and further transformed into an air slot via selective wet etching for optical index and biomolecule sensing. (C) 2012 Optical Society of America
Spontaneous subpicosecond pulse formation with pulse repetition rate of 80 GHz in a diode-pumped Nd:SrGdGa3O7 disordered crystal laser
(2012-02-15)
Chen, Y. F.
;
Liang, H. C.
;
Tung, J. C.
;
Su, K. W.
;
Zhang, Y. Y.
We explore the operation of spontaneous mode locking in a diode-pumped Nd:SrGdGa3O7 disordered crystal laser. The first- and second-order autocorrelations are simultaneously performed to evaluate the temporal characteristics. An 80 GHz pulse train with a pulse duration as short as 616 fs is observed. The maximum output power is 415 mW at a pump power of 6.1 W. (C) 2012 Optical Society of America
Surface modification of poly(2-methoxy-5-(2 '-ethyl-hexyloxy)-1,4-phenylene vinylene) (MEH-PPV) by confined photo-catalytic oxidation
(2012-02-15)
Yen, Ying-Chieh
;
Cheng, Chih-Chia
;
Wang, Yeh-Sheng
;
Chu, Yu-Lin
;
Lu, Chu-Hua
In this study, the surface of pi-conjugated polymer, poly(2-methoxy-5(2'-ethyl-hexyloxy)-1,4-phenylene vinylene) (MEH-PPV), was successfully modified with the sulfate anion (SO4-) groups by the confined photo-catalytic oxidation (CPO). After the surface modification, the water contact angle of MEH-PPV is changed from 95.5 degrees to 82.1 degrees without influence on its optical properties (based on the UV and PL spectra), and the water droplet can be absorbed on the modified MEH-PPV surface without sliding even at substrate tilt angles of 90 degrees and 180 degrees. The CPO on the MEH-PPV surface is able to further expand the use of MEH-PPV for applications. In addition, the water transport test indicates that the modified MEH-PPV can be a candidate for transporting water droplet. (C) 2011 Elsevier Inc. All rights reserved.
Generalized synchronization of chaotic systems with different orders by fuzzy logic constant controller (vol 38, pg 2302, 2011)
(2012-02-15)
Li, Shih-Yu
;
Ge, Zheng-Ming
;
機械工程學系
;
Department of Mechanical Engineering
Enhanced performance and reliability of NILC-TFTs using FSG buffer layer
(2012-02-15)
Chen, Chien-Chih
;
Wu, YewChung Sermon
;
Chang, Chih-Pang
;
材料科學與工程學系
;
Department of Materials Science and Engineering
A new manufacturing method for Ni-metal-induced lateral crystallization thin film transistors (NILC-TFTs) using fluorine-silicate-glass (FSG) was proposed. In FSG-TFTs, fluorine ion was implanted into the buffer oxide layer to form FSG before NILC processes. It was found FSG-TFTs exhibit high field-effect mobility, low threshold voltage, low subthreshold slope, high ON/OFF current ratio, low trap state density, low interface trap state density, and good reliability compared with typical NILC-TFTs. (c) 2011 Elsevier B.V. All rights reserved.
Synthesis of fluorene-based hyperbranched polymers for solution-processable blue, green, red, and white light-emitting devices
(2012-02-15)
Shih, Hung-Min
;
Wu, Ren-Chi
;
Shih, Ping-I
;
Wang, Chien-Lung
;
Hsu, Chain-Shu
For the purpose of making hyperbranched polymer (Hb-Ps)-based red, green, blue, and white polymer light-emitting diodes (PLEDs), three Hb-Ps Hb-terfluorene (Hb-TF), Hb-4,7-bis(9,9'-dioctylfluoren-2-yl)-2,1,3-benzothiodiazole (Hb-BFBT), and Hb-4,7-bis[(9,9'-dioctylfluoren-2-yl)-thien-2-yl]-2,1,3-benzothiodiazole (Hb-BFTBT) were synthesized via [2+2+2] polycyclotrimerization of the corresponding diacetylene-functionalized monomers. All the synthesized polymers showed excellent thermal stability with degradation temperature higher than 355 degrees C and glass transition temperatures higher than 50 degrees C. Photoluminance (PL) and electroluminance (EL) spectra of the polymers indicate that Hb-TF, Hb-BFBT, and Hb-BFTBT are blue-green, green, and red emitting materials. Maximum brightness of the double-layer devices of Hb-TF, Hb-BFBT, and Hb-BFTBT with the device configuration of indium tin oxide/poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate)/light-emitting polymer/CsF/Al are 48, 42, and 29 cd/m(2); the maximum luminance efficiency of the devices are 0.01, 0.02, and 0.01 cd/A. By using hostguest doped system, saturated red electrophosphorescent devices with a maximum luminance efficiency of 1.61 cd/A were obtained when Hb-TF was used as a host material doped with Os(fptz)(2)(PPh(2)Me(2))(2) as a guest material. A maximum luminance efficiency of 3.39 cd/A of a red polymer light-emitting device was also reached when Hb-BFTBT was used as the guest in the PFO (Poly(9,9-dioctylfluorene)) host layer. In addition, a series of efficient white devices were, which show low turn-on voltage (3.5 V) with highest luminance efficiency of 4.98 cd/A, maximum brightness of 1185 cd/m(2), and the Commission Internationale de l'Eclairage (CIE) coordinates close to ideal white emission (0.33, 0.33), were prepared by using BFBT as auxiliary dopant. (c) 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: 696-710, 2012
Existence of traveling wave solutions for diffusive predator-prey type systems
(2012-02-15)
Hsu, Cheng-Hsiung
;
Yang, Chi-Ru
;
Yang, Ting-Hui
;
Yang, Tzi-Sheng
;
應用數學系
In this work we investigate the existence of traveling wave solutions for a class of diffusive predator-prey type systems whose each nonlinear term can be separated as a product of suitable smooth functions satisfying some monotonic conditions. The profile equations for the above system can be reduced as a four-dimensional ODE system, and the traveling wave solutions which connect two different equilibria or the small amplitude traveling wave train solutions are equivalent to the heteroclinic orbits or small amplitude periodic solutions of the reduced system. Applying the methods of Wazewski Theorem, LaSalle's Invariance Principle and Hopf bifurcation theory, we obtain the existence results. Our results can apply to various kinds of ecological models. (C) 2011 Elsevier Inc. All rights reserved.
Constructing a yield model for integrated circuits based on a novel fuzzy variable of clustered defect pattern
(2012-02-15)
Lin, Jun-Shuw
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工業工程與管理學系
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Department of Industrial Engineering and Management
As the wafer size increases, the clustering phenomenon of defects becomes significant. In addition to clustered defects, various clustering patterns also influence the wafer yield. In fact, the recognition of clustering pattern usually exists fuzziness. However, the wafer yield models in previous studies did not consider the fuzziness of clustering pattern belonging to which shape in recognition. Therefore, the objective of this study is to develop a new fuzzy variable of clustering pattern (FVCP) by using fuzzy logic control, and predict the wafer yield by using back-propagation neural network (BPNN) incorporating ant colony optimization (ACO). The proposed method utilizes defect counts, cluster index (CI), and FVCP as inputs for ACO-BPNN. A simulated study is utilized to demonstrate the effectiveness of the proposed model. (C) 2011 Elsevier Ltd. All rights reserved.