Browsing by Issue Date, starting with "2015-03-30"

Now showing 1 - 20 of 22187

Hybrid OpenMP/AVX acceleration of a Split HLL Finite Volume Method for the Shallow Water and Euler Equations
(2015-03-30)
Liu, Ji-Yueh
;
Smith, Matthew R.
;
Kuo, Fang-An
;
Wu, Jong-Shin
;
機械工程學系
Presented is the application of the Split Harten, Lax and van Leer (SHLL) technique applied to parallel computation using a hybrid OpenMP/AVX parallelization paradigm for the Shallow Water Equations and Euler Equations. The key behind the ease of parallelization of the SHLL method for both governing equations is the mathematical/vector splitting in each coordinate direction - this splitting results in a high degree of locality, producing a scheme which is embarrassingly parallel and well suited for the vectorization capacities offered by vector-computing architectures. Here we demonstrate this capacity using the SIMD capacities of modern CPUs, namely the Advanced Vector eXtensions (AVX) capability of recent CPUs. The main feature of AVX is the capacity to perform SIMD operations on 8 floating point variables in parallel - an increase from 4 floating point variables as possible using the previous SIMD Streaming Extensions (SSE). Furthermore, since modern CPU\'s employ a large number of cores, we further extend the performance by using AVX on each available CPU core using shared memory (OpenMP) parallelization. We present a direction-split higher order extension to both the SHLL method and apply it to AVX through the use of intrinsic functions in the flux computation and state computation modules. High performance is obtained by ensuring that all flux computations are performed using only AVX intrinsic functions - no computations are performed in serial. Through this approach, a single workstation with 2x Xeon CPU\'s (16 physical cores) allows a performance increase of over 117 times that of a single core alone in the flux evaluation kernel. (C) 2014 Elsevier Ltd. All rights reserved.
Manipulation of exciton and photon lasing in a membrane-type ZnO microcavity
(2015-03-30)
Lai, Ying-Yu
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Chen, Jee-Wei
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Chang, Tsu-Chi
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Chou, Yu-Hsun
;
Lu, Tien-Chang
We report on the fabrication and characterization of a membrane-type ZnO microcavity (MC). The ZnO membrane was cut from a single crystalline ZnO substrate by using focused ion beam milling, and was then placed onto a SiO2 substrate by using glass microtweezers. Through changing the pumping regime, manipulation of P-band exciton lasing and whispering-gallery mode (WGM) photon lasing could be easily achieved. P-band exciton lasing was observed only when the pumping laser was focused at the center of the ZnO MC with a small pumping size because of the innate ring-shaped WGM distribution. Furthermore, the lasing threshold of the ZnO MC could be reduced to an order lower by using a larger pumping spot because of the more favorable spatial overlap between the optical gain and WGM. (C) 2015 AIP Publishing LLC.
Method for automatic detection and tracking of multiple targets with multiple cameras and system therefor
(2015-03-31)
Huang Ching-Chun
;
Wang Sheng-Jyh
A method for automatically detecting and tracking multiple targets in a multi-camera surveillance zone and system thereof. In each camera view of the system only a simple object detection algorithm is needed. The detection results from multiple cameras are fused into a posterior distribution, named TDP, based on the Bayesian rule. This TDP distribution represents a likelihood of presence of some moving targets on the ground plane. To properly handle the tracking of multiple moving targets with time, a sample-based framework which combines Markov Chain Monte Carlo (MCMC), Sequential Monte Carlo (SMC), and Mean-Shift Clustering, is provided. The detection and tracking accuracy is evaluated by both synthesized videos and real videos. The experimental results show that this method and system can accurately track a varying number of targets.
Driving circuit for dual organic light emitting diodes, and dual-pixel circuit incorporating the same
(2015-03-31)
Lee Kuei-Yu
;
Chao Paul C. P.
A dual-pixel circuit includes first and second OLEDs, and a driving circuit that includes first and second driving transistors, a capacitor, and a switching module operable between first and second modes based on a data voltage, first and second scan voltages, and first and second bias signals. When the switching module is operated in the first mode, the first OLED is forward-biased to emit light, and the second OLED is reverse-biased. When the switching module is operated in the second mode, the first OLED is reverse-biased, and the second OLED is forward-biased to emit light.
Semiconductor optical device having an air media layer and the method for forming the air media layer thereof
(2015-03-31)
Lu Tien-Chang
;
Huang Huei-Min
;
Kuo Hao-Chung
;
Wang Shing-Chung
A method for fabricating air media layer within the semiconductor optical device is provided. The step of method includes a substrate is provided, a GaN thin film is formed on the substrate, a sacrificial layer is formed on the GaN thin film, and a nitride-containing semiconductor layer is formed on the sacrificial layer. The semiconductor optical device is immersed with an acidic solution to remove the portion of sacrificial layer to form an air media layer around the residual sacrificial layer.
Anthryl-1,2,4-oxadiazole-Substituted Calix[4]arenes as Highly Selective Fluorescent Chemodosimeters for Fe3+
(2015-04-01)
Chen, Ying-Jung
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Yang, Shun-Chieh
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Tsai, Chia-Chen
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Chang, Kai-Chi
;
Chuang, Wen-Han
Fluorescent chemosensors 1 and 2, with 1,2,4-oxadiazoles as the binding ligands and anthracene as the fluorophore, were synthesized through sequential 1,3-dipolar cycloaddition reactions of 25,27-dioxyacetonitrilecalix[4]arenes 8 and 11. The fluorescence of 1 was severely quenched by both Fe3+ and Cu2+, whereas that of 2 was selectively quenched only by Fe3+. Control compound 4 was also selectively quenched by Fe3+, which implied the importance of anthryl-1,2,4-oxadiazole core; furthermore, it was shown to give various oxidation products such as oxanthrone 13, anthraquinone 14, and imidazolyl oxanthrone 15. In addition to product separation and identification, the fluorescent quenching mechanism of these 9-anthryl-1,2,4-oxadiazolyl derivatives by Fe3+ is also discussed. Furthermore, it should be noted that the oxadiazole-substituted anthracene 4 and calix[4]arene 2 are Fe3+-selective fluorescent chemodosimeters without the interference by Cu2+.
【活動快訊】2015陽明大學牙醫校友會迎新暨聯合徵才
(國立陽明大學牙醫校友會, 2015-04)
楊大為
TiO2-Based Indium Phosphide Metal-Oxide-Semiconductor Capacitor with High Capacitance Density
(2015-04-01)
Cheng, Chun-Hu
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Hsu, Hsiao-Hsuan
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Chou, Kun-I
;
電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
We report a low-temperature InP p-MOS with a high capacitance density of 2.7 mu F/cm(2), low leakage current of 0.77 A/cm(2) at 1 V and tight current distribution. The high-density and low-leakage InP MOS was achieved by using high-kappa TiLaO dielectric and ultra-thin SiO2 buffer layer with a thickness of less than 0.5 nm. The obtained EOT can be aggressively scaled down to <1 nm through the use of stacked TiLaO/SiO2 dielectric, which has the potential for the future application of high mobility III-V CMOS devices.
A bound on the Laplacian spread which is tight for strongly regular graphs
(2015-04-01)
Lin, Fan-Hsuan
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Weng, Chih-wen
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應用數學系
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Department of Applied Mathematics
The Laplacian spread of a graph is the difference between the largest eigenvalue and the second-smallest eigenvalue of the Laplacian matrix of the graph. For Laplacian matrices of graphs, we find their upper bounds of largest eigenvalues, lower bounds of second-smallest eigenvalues and upper bounds of Laplacian spreads. The strongly regular graphs attain all the above bounds. Some other extremal graphs are also provided. (C) 2015 Elsevier Inc. All rights reserved.
左翼浮沉歷史與運動組織的始與終
(深河出版有限公司, 2015-04-01)
夏林清
社會運動與學術研究《左工二流誌》的衝擊
(深河出版有限公司, 2015-04-01)
謝國雄
Simultaneous estimation of the locations and effects of multiple disease loci in case-control studies
(2015-04-01)
Chien, Li-Chu
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Chiu, Yen-Feng
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Liang, Kung-Yee
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Chuang, Lee-Ming
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統計學研究所
The genetic basis of complex diseases often involves multiple causative loci. Under such a disease etiology, assuming one disease locus in linkage disequilibrium mapping is likely to induce bias and lead to efficiency loss in disease locus estimation. An approach is needed for simultaneously localizing multiple functional loci within the same region. However, due to the increasing number of parameters accompanying disease loci, these estimates can be computationally infeasible. To circumvent this problem, we propose to estimate the main and two-adjacent-locus joint effects and a nuisance parameter at the disease loci separately through a linear approximation. Estimates of the genetic effects are entered into a generalized estimating equation to estimate disease loci, and the procedure is conducted iteratively until convergence. The proposed method provides estimates and confidence intervals (CIs) for the disease loci, the genetic main effects, and the joint effects of two adjacent disease loci, with the CIs for the disease loci providing useful regions for further fine-mapping. We apply the proposed approach to a data example of case-control studies. Results of the simulations and data example suggest that the developed method performs well in terms of bias, variance, and coverage probability under scenarios with up to three disease loci.
Trapped charge-induced pyroelectric-like transient response in single high-resistivity Sb2Se3 nanowires
(2015-04-01)
Ko, T. Y.
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Sun, K. W.
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應用化學系
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電子工程學系及電子研究所
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Department of Applied Chemistry
Dynamic scanning photocurrent microscopy was applied to Sb2Se3 crystalline single nanowires (NWs) to analyze their transient photocurrent responses. These NWs exhibited switching behavior with rapid rise and decay times upon illumination by laser pulses. The estimated spectral responsivity and external quantum efficiency for a freshly-prepared NW at a bias voltage of 0.3 V and excitation wavelength of 488 nm were similar to 16.9 mA/W and similar to 42.9%, respectively. A pyroelectric-like current transient was observed with reduced spectral responsivity when nonpolar Sb2Se3 single-crystalline NWs were excited by laser pulses. Because Sb2Se3 NWs were non-pyroelectric or ferroelectric, the pyroelectric-like current could possibly be attributed to temperature dependent nonlinear space-charge distributions. Defects produced by the external electrical bias generated and re-distributed space charges in the NWs. As a result, the temperature dependent inhomogeneous electric field led to nonlinear expansions or contractions of the lattice (electrostriction) that can produce pyroelectric current. We obtained a lower bound of equivalent pyroelectric coefficient a >= 60.09 mu C/m(2) K from these materials by fitting the electrical transients. (C) 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
A Tetraperylene Diimides Based 3D Nonfullerene Acceptor for Efficient Organic Photovoltaics
(2015-04)
Liu, Shi-Yong
;
Wu, Chen-Hao
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Li, Chang-Zhi
;
Liu, Sheng-Qiang
;
Wei, Kung-Hwa
A Tetraperylene Diimides Based 3D Nonfullerene Acceptor for Efficient Organic Photovoltaics
(2015-04-01)
Liu, Shi-Yong
;
Wu, Chen-Hao
;
Li, Chang-Zhi
;
Liu, Sheng-Qiang
;
Wei, Kung-Hwa
虱目魚與太陽花－為何、以及如何「寄希望於台灣人民」
(深河出版有限公司, 2015-04-01)
李娜
尋索存於「異議之聲」的記憶
(深河出版有限公司, 2015-04-01)
陳瑩恩
A Systolic Array Based GTD Processor With a Parallel Algorithm
(2015-04-01)
Yang, Chia-Hsiang
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Chou, Chun-Wei
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Hsu, Chia-Shen
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Chen, Chiao-En
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電子工程學系及電子研究所
Generalized triangular decomposition (GTD) has been found to be useful in the field of signal processing, but the feasibility of the related hardware has not yet been established. This paper presents (for the first time) a GTD processor architecture with a parallel algorithm. The proposed parallel GTD algorithm achieves an increase in speed of up to 1.66 times, compared to the speed of its conventional sequential counterpart for an 8x8 matrix. For hardware implementation, the proposed reconfigurable architecture is capable of computing singular value decomposition (SVD), geometric mean decomposition (GMD), and GTD for matrix sizes from 1x1 to 8x8. The proposed GTD processor is composed of 16 processing cores in a heterogeneous systolic array. Computations are distributed over area-efficient coordinate rotation digital computers (CORDICs) to achieve a high throughput. To establish the validity of the concept, a GTD processor was designed and implemented. The latency constraint of 16 mu s specified in the 802.11ac standard is adopted for the hardware realization. The proposed design achieves a maximum throughput of 83.3k matrices/s for an 8x8 matrix at 112.4 MHz. The estimated power and core area are 172.7 mW and 1.96 mm(2), respectively, based on standard 90 nm CMOS technology.
Glycosylation Chemistry of 3-Deoxy-D-manno-Oct-2-ulosonic Acid (Kdo) Donors
(2015-04-01)
Pradhan, Tapan Kumar
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Mong, Kwok Kong Tony
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交大名義發表
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National Chiao Tung University
3-Deoxy-D-manno-Oct-2-ulosonic acid (Kdo)-containing oligosaccharides are a conserved carbohydrate component in lipopolysaccharides ( LPSs) of the outer membrane of Gram-negative bacteria, and they are also present in capsular polysaccharides ( CPSs) of bacteria and plant cells. The association of the bacterial LPS with the pathophysiology of bacterial infection have long been recognized. Structure-pathophysiology studies of bacterial infection need to use pure and homogeneous LPS fragments. Such a requirement can be fulfilled by the synthesis of Kdo glycosides and related Kdo-oligosaccharide conjugates. This article provides an overview of the glycosylation chemistries of the synthesis of Kdo alpha-/beta-glycosides, oligosaccharides with Kdo units such as LPS core oligosaccharides, and lipid A derivatives.
Electrically induced red, green, and blue scattering in chiral-nematic thin films
(2015-04-01)
Hsiao, Yu-Cheng
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Lee, Wei
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影像與生醫光電研究所
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Institute of Imaging and Biomedical Photonics
Cholesteric liquid-crystalline materials are abundant in nature such as condensed phases of DNA, plant cell walls, and chiral biopolymers. These self-organized helical structures produce unique optical properties, giving rise to the selective Bragg reflection of colorful light. In this Letter, we focus on the focal conic state of cholesteric liquid crystals and report on stable, tunable, and reversible color switching among red, green, and blue in polymer-stabilized cholesteric films. The experimental results indicate that, with appropriate voltage pulses, the electrically induced color switching of all six routes can be realized in a single cell reflecting green light. The scattered transmissive color persists at zero voltage due to the polymer stabilization. (C) 2015 Optical Society of America