Browsing by Issue Date, starting with "2016-05-02"

Now showing 1 - 20 of 17346

Development of semiclassical molecular dynamics simulation method
(2016-05-02)
Nakamura, Hiroki
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Nanbu, Shinkoh
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Teranishi, Yoshiaki
;
Ohta, Ayumi
;
應用化學系分子科學碩博班
Various quantum mechanical effects such as nonadiabatic transitions, quantum mechanical tunneling and coherence play crucial roles in a variety of chemical and biological systems. In this paper, we propose a method to incorporate tunneling effects into the molecular dynamics (MD) method, which is purely based on classical mechanics. Caustics, which define the boundary between classically allowed and forbidden regions, are detected along classical trajectories and the optimal tunneling path with minimum action is determined by starting from each appropriate caustic. The real phase associated with tunneling can also be estimated. Numerical demonstration with use of a simple collinear chemical reaction O + HCl -> OH + Cl is presented in order to help the reader to well comprehend the method proposed here. Generalization to the on-the-fly ab initio version is rather straightforward. By treating the nonadiabatic transitions at conical intersections by the Zhu-Nakamura theory, new semiclassical MD methods can be developed.
RGB visible light communication using mobile-phone camera and multi-input multi-output
(2016-05-02)
Liang, Kevin
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Chow, Chi-Wai
;
Liu, Yang
;
光電工程學系
;
光電工程研究所
Red, green, blue (RGB) light-emitting-diodes (LEDs) are used to increase the visible light communication (VLC) transmission capacity via wavelength-division-multiplexing (WDM), and the color image sensor in mobile phone is used to separate different color signals via a color filter array. However, due to the wide optical bandwidths of the color filters, there is a high spectral overlap among different channels, and a high interchannel interference (ICI) happens. Here, we propose and demonstrate an RGB VLC transmission using CMOS image sensor with multi-input multioutput (MIMO) technique to mitigate the ICI and retrieve the three independent color channels in the rolling shutter pattern. Data pattern extinction-ratio (ER) enhancement and thresholding are deployed. (C) 2016 Optical Society of America
Impacts of Co doping on ZnO transparent switching memory device characteristics
(2016-05-02)
Simanjuntak, Firman Mangasa
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Prasad, Om Kumar
;
Panda, Debashis
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Lin, Chun-An
;
Tsai, Tsung-Ling
The resistive switching characteristics of indium tin oxide (ITO)/Zn1-xCoxO/ITO transparent resistive memory devices were investigated. An appropriate amount of cobalt dopant in ZnO resistive layer demonstrated sufficient memory window and switching stability. In contrast, pure ZnO devices demonstrated a poor memory window, and using an excessive dopant concentration led to switching instability. To achieve suitable memory performance, relying only on controlling defect concentrations is insufficient; the grain growth orientation of the resistive layer must also be considered. Stable endurance with an ON/OFF ratio of more than one order of magnitude during 5000 cycles confirmed that the Co-doped ZnO device is a suitable candidate for resistive random access memory application. Additionally, fully transparent devices with a high transmittance of up to 90% at wavelength of 550 nm have been fabricated. Published by AIP Publishing.
Radio-over-fiber DSB-to-SSB conversion using semiconductor lasers at stable locking dynamics
(2016-05-02)
Hsieh, Kun-Lin
;
Hung, Yu-Han
;
Hwang, Sheng-Kwang
;
Lin, Chien-Chung
;
光電系統研究所
In radio-over-fiber systems, optical single-sideband (SSB) modulation signals are preferred to optical double-sideband (DSB) modulation signals for fiber distribution in order to mitigate the microwave power fading effect. However, typically adopted modulation schemes generate DSB signals, making DSB-to-SSB conversion necessary before or after fiber distribution. This study investigates a semiconductor laser at stable locking dynamics for such conversion. The conversion relies solely on the nonlinear dynamical interaction between an input DSB signal and the laser. Only a typical semiconductor laser is therefore required as the key conversion unit, and no pump or probe signal is necessary. The conversion can be achieved for a broad tunable range of microwave frequency up to at least 60 GHz. In addition, the conversion can be carried out even when the microwave frequency, the power of the input DSB signal, or the frequency of the input DSB signal fluctuates over a wide range, leading to high adaptability and stability of the conversion system. After conversion, while the microwave phase quality, such as linewidth and phase noise, is mainly preserved, a bit-error ratio down to 10(-9) is achieved for a data rate up to at least 8 Gb/s with a detection sensitivity improvement of more than 1.5 dB. (C) 2016 Optical Society of America
Neural Mechanisms of Inhibitory Response in a Battlefield Scenario: A Simultaneous fMRI-EEG Study
(2016-05-02)
Ko, Li-Wei
;
Shih, Yi-Cheng
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Chikara, Rupesh Kumar
;
Chuang, Ya-Ting
;
Chang, Erik C.
The stop-signal paradigm has been widely adopted as a way to parametrically quantify the response inhibition process. To evaluate inhibitory function in realistic environmental settings, the current study compared stop-signal responses in two different scenarios: one uses simple visual symbols as go and stop signals, and the other translates the typical design into a battlefield scenario (BFS) where a sniper-scope view was the background, a terrorist image was the go signal, a hostage image was the stop signal, and the task instructions were to shoot at terrorists only when hostages were not present but to refrain from shooting if hostages appeared. The BFS created a threatening environment and allowed the evaluation of how participants' inhibitory control manifest in this realistic stop-signal task. In order to investigate the participants' brain activities with both high spatial and temporal resolution, simultaneous functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) recordings were acquired. The results demonstrated that both scenarios induced increased activity in the right inferior frontal gyrus (rIFG) and presupplementary motor area (preSMA), which have been linked to response inhibition. Notably, in right temporoparietal junction (rTPJ) we found both higher blood-oxygen-level dependent (BOLD) activation and synchronization of theta-alpha activities (4-12 Hz) in the BFS than in the traditional scenario after the stop signal. The higher activation of rTPJ in the BFS may be related to morality judgments or attentional reorienting. These results provided new insights into the complex brain networks involved in inhibitory control within naturalistic environments.
NF-kappa B-driven suppression of FOXO3a contributes to EGFR mutation-independent gefitinib resistance
(2016-05-03)
Chiu, Ching-Feng
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Chang, Yi-Wen
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Kuo, Kuang-Tai
;
Shen, Yu-Shiuan
;
Liu, Chien-Ying
Therapy with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (EGFR-TKIs, such as gefitinib or erlotinib) significantly prolongs survival time for patients with tumors harboring an activated mutation on EGFR; however, up to 40% of lung cancer patients exhibit acquired resistance to EGFR-TKIs with an unknown mechanism. FOXO3a, a transcription factor of the forkhead family, triggers apoptosis, but the mechanistic details involved in EGFR-TKI resistance and cancer stemness remain largely unclear. Here, we observed that a high level of FOXO3a was correlated with EGFR mutation-independent EGFR-TKI sensitivity, the suppression of cancer stemness, and better progression-free survival in lung cancer patients. The suppression of FOXO3a obviously increased gefitinib resistance and enhanced the stem-like properties of lung cancer cells; consistent overexpression of FOXO3a in gefitinib-resistant lung cancer cells reduced these effects. Moreover, we identified that miR-155 targeted the 3\'UTR of FOXO3a and was transcriptionally regulated by NF-kappa B, leading to repressed FOXO3a expression and increased gefitinib resistance, as well as enhanced cancer stemness of lung cancer in vitro and in vivo. Our findings indicate that FOXO3a is a significant factor in EGFR mutation-independent gefitinib resistance and the stemness of lung cancer, and suggest that targeting the NF-kappa B/miR-155/FOXO3a pathway has potential therapeutic value in lung cancer with the acquisition of resistance to EGFR-TKIs.
Modular design and implementation of field-programmable-gate-array-based Gaussian noise generator
(2016-05-03)
Li, Yuan-Ping
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Lee, Ta-Sung
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Hwang, Jeng-Kuang
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電機工程學系
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Department of Electrical and Computer Engineering
The modular design of a Gaussian noise generator (GNG) based on field-programmable gate array (FPGA) technology was studied. A new range reduction architecture was included in a series of elementary function evaluation modules and was integrated into the GNG system. The approximation and quantisation errors for the square root module with a first polynomial approximation were high; therefore, we used the central limit theorem (CLT) to improve the noise quality. This resulted in an output rate of one sample per clock cycle. We subsequently applied Newton\'s method for the square root module, thus eliminating the need for the use of the CLT because applying the CLT resulted in an output rate of two samples per clock cycle (>200 million samples per second). Two statistical tests confirmed that our GNG is of high quality. Furthermore, the range reduction, which is used to solve a limited interval of the function approximation algorithms of the System Generator platform using Xilinx FPGAs, appeared to have a higher numerical accuracy, was operated at >350MHz, and can be suitably applied for any function evaluation.
A Decision Support System Based on a Genetic Algorithm for the Utilization of Leftovers
(2016-05-03)
Fu, Hsin-Pin
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Ku, Cheng-Yuan
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Chang, Tsung-Sheng
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資訊管理與財務金融系註：原資管所+財金所
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Department of Information Management and Finance
There are usually some leftovers (usable pieces of raw material) and scraps (unusable pieces of raw material).generated after the completion of a manufacturing process. These leftovers consist of many different types, materials, styles and sizes so the use of such materials is difficult to manage, resulting in a significant material management problem for manufacturers. This study examines ways to use these leftovers and proposes the application of a genetic algorithm to handle the problem of matching usable leftovers to incoming orders. In order to verify the feasibility of the solution, a decision support system was implemented, based on a genetic algorithm. With lots of experimental results, we conclude this method is thus of considerable value to the managers of manufacturing factories.
Determination of Percent Crystallinity of Side-Chain Crystallized Alkylated-Dextran Derivatives with Raman Spectroscopy and Multivariate Curve Resolution
(2016-05-03)
Samuel, Ashok Zachariah
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Zhou, Mengbo
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Ando, Masahiro
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Mueller, Robert
;
Liebert, Tim
We demonstrate a methodology to estimate the percent crystallinity of polymers directly with Raman spectroscopy and multivariate curve resolution (MCR) by alternating least-squares (ALS). In this methodology, the Raman spectrum of semicrystalline polymer is separated into two constituent components (crystalline and molten) and their corresponding concentrations. The percent crystallinity can be estimated as the change in area intensity of the molten spectral-component when polymer cools from a temperature above melting point to room temperature. The number of carbons in the crystalline lattice has also been estimated from the position of longitudinal acoustic (LA) Raman bands with the correlation established by Mizushima and Simanouti [Mizushima, S.; Simanouti, T. J. Am. Chem. Soc. 1949, 71, 1320]. The new method allows direct Raman estimation of absolute percent crystallinity of polymers. Until now, Raman spectroscopic estimation of percent crystallinity was possible only in conjunction with other techniques or by using internal standards.
Efficiently sphere-decodable physical layer transmission schemes for wireless storage networks
(2016-05-05)
Lu, Hsiao-feng (Francis)
;
Barreal, Amaro
;
Karpuk, David
;
Hollanti, Camilla
;
資訊工程學系
Three transmission schemes over a new type of multiple-access channel (MAC) model with inter-source communication links are proposed and investigated in this paper. This new channel model is well motivated by, e.g., wireless distributed storage networks, where communication to repair a lost node takes place from helper nodes to a repairing node over a wireless channel. Since in many wireless networks nodes can come and go in an arbitrary manner, there must be an inherent capability of inter-node communication between every pair of nodes. Assuming that communication is possible between every pair of helper nodes, the newly proposed schemes are based on various smart time-sharing and relaying strategies. In other words, certain helper nodes will be regarded as relays, thereby converting the conventional uncooperative multiple-access channel to a multiple-access relay channel (MARC). The diversity-multiplexing gain tradeoff (DMT) of the system together with efficient sphere-decodability and low structural complexity in terms of the number of antennas required at each end is used as the main design objectives. While the optimal DMT for the new channel model is fully open, it is shown that the proposed schemes outperform the DMT of the simple time-sharing protocol and, in some cases, even the optimal uncooperative MAC DMT. While using a wireless distributed storage network as a motivating example throughout the paper, the MAC transmission techniques proposed here are completely general and as such applicable to any MAC communication with inter-source communication links.
Efficiently sphere-decodable physical layer transmission schemes for wireless storage networks
(2016-05-05)
Lu, Hsiao-feng (Francis)
;
Barreal, Amaro
;
Karpuk, David
;
Hollanti, Camilla
;
電機工程學系
Three transmission schemes over a new type of multiple-access channel (MAC) model with inter-source communication links are proposed and investigated in this paper. This new channel model is well motivated by, e.g., wireless distributed storage networks, where communication to repair a lost node takes place from helper nodes to a repairing node over a wireless channel. Since in many wireless networks nodes can come and go in an arbitrary manner, there must be an inherent capability of inter-node communication between every pair of nodes. Assuming that communication is possible between every pair of helper nodes, the newly proposed schemes are based on various smart time-sharing and relaying strategies. In other words, certain helper nodes will be regarded as relays, thereby converting the conventional uncooperative multiple-access channel to a multiple-access relay channel (MARC). The diversity-multiplexing gain tradeoff (DMT) of the system together with efficient sphere-decodability and low structural complexity in terms of the number of antennas required at each end is used as the main design objectives. While the optimal DMT for the new channel model is fully open, it is shown that the proposed schemes outperform the DMT of the simple time-sharing protocol and, in some cases, even the optimal uncooperative MAC DMT. While using a wireless distributed storage network as a motivating example throughout the paper, the MAC transmission techniques proposed here are completely general and as such applicable to any MAC communication with inter-source communication links.
Quantum criticality of the two-channel pseudogap Anderson model: universal scaling in linear and non-linear conductance
(2016-05-05)
Wu, Tsan-Pei
;
Wang, Xiao-Qun
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Guo, Guang-Yu
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Anders, Frithjof
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Chung, Chung-Hou
The quantum criticality of the two-lead two-channel pseudogap Anderson impurity model is studied. Based on the non-crossing approximation (NCA) and numerical renormalization group (NRG) approaches, we calculate both the linear and nonlinear conductance of the model at finite temperatures with a voltage bias and a power-law vanishing conduction electron density of states, rho(c)(omega) alpha | omega-mu(F)|(r) (0 < r < 1) near the Fermi energy mu(F). At a fixed leadimpurity hybridization, a quantum phase transition from the two-channel Kondo (2CK) to the local moment (LM) phase is observed with increasing r from r = 0 to r = r(c) < 1. Surprisingly, in the 2CK phase, different power-law scalings from the well-known root T or root V form is found. Moreover, novel power-law scalings in conductances at the 2CK-LM quantum critical point are identified. Clear distinctions are found on the critical exponents between linear and non-linear conductance at criticality. The implications of these two distinct quantum critical properties for the non-equilibrium quantum criticality in general are discussed.
交大e-News第208期-以植物盆栽促進人類溝通頻率交大團隊奪高齡設計賽全球第三
(2016-05-05)
國立交通大學秘書室
;
Secretariat
Drag force of Anisotropic plasma at finite U(1) chemical potential
(2016-05-05)
Cheng, Long
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Ge, Xian-Hui
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Wu, Shang-Yu
;
電子物理學系
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Department of Electrophysics
We perform the calculation of the drag force acting on amassive quark moving through an anisotropic N = 4 SU(N) Super Yang-Mills plasma in the presence of a U(1) chemical potential. We present the numerical results for any value of the anisotropy and arbitrary direction of the quark velocity with respect to the direction of the anisotropy. We find the effect of the chemical potential or charge density will enhance the drag force for our charged solution.
Economic dispatch of chiller plant by improved ripple bee swarm optimization algorithm for saving energy
(2016-05-05)
Lo, Chi-Chun
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Tsai, Shang-Ho
;
Lin, Bor-Shyh
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影像與生醫光電研究所
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電控工程研究所
This paper presents an improved ripple bee swarm optimization (IRBSO) algorithm to solve the problem of the economic dispatch of chiller plants (EDCP). Using the characteristics of biological communities, different movement models are adopted to search within the feasible solution space. This paper uses nonlinear ripple weight factors and self-adaption repulsion factor to improve the BSO and proposes the influence of parameters on the IRBSO method to more effectively search the feasible space. For all bee swarms, the efficiency of searching movement in the solution space improves, and the capacity of information discovery and mining increases. This paper utilizes the test cases to verify the proposed IRBSO, including EDCP problems for a single day and a single week. Compared with other methods, the results of the proposed IRBSO exhibit higher accuracy and stability, making it suitable for the operation planning of multiple chiller systems. (C) 2016 Elsevier Ltd. All rights reserved.
Remarks on the weak formulation of the Navier-Stokes equations on the 2D hyperbolic space
(2016-05-06)
Chan, Chi Hin
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Czubak, Magdalena
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應用數學系
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Department of Applied Mathematics
The Leray-Hopf solutions to the Navier Stokes equation are known to be unique on R-2. In our previous work, we showed the breakdown of uniqueness in a hyperbolic setting. In this article, we show how to formulate the problem in order so the uniqueness can be restored. (C) 2015 Elsevier Masson SAS. All rights reserved.
Functional Connectivity During Phonemic and Semantic Verbal Fluency Test: A Multichannel Near Infrared Spectroscopy Study
(2016-05-06)
Huang, Chun-Jung
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Chou, Po-Han
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Wei, Hao-Lin
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Sun, Chia-Wei
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光電工程學系
Verbal fluency tests (VFTs) are widely used frontal lobe neuropsychological tests. They have been frequently used in various functional brain mapping studies. There are two versions of VFTs based on the type of cue: the letter fluency task (LFT) and the category fluency task (CFT). However, the fundamental aspects of brain connectivity across the frontotemporal regions during the VFTs have not been elucidated. In this study, we hypothesized that differences in cortical functional connectivity over the left and right frontotemporal regions may be observed by means of multi-channel functional near-infrared spectroscopy (fNIRS) during the performance of LFT and CFT. Our results from fNIRS (ETG-4000) showed different patterns of brain functional connectivity during the two types of VFTs, which was consistent with the different cognitive requirements of each task. We demonstrate increased brain functional connectivity over the frontal and temporal regions during the LFT than during the CFT; these results are in line with previous brain activity studies using fNIRS to demonstrate higher frontal and temporal region activation during LFT and CFT, with more pronounced frontal activation by the LFT.
傢俱魔法師　理念付諸設計
(2016-05-08)
修瑞韓
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Department of Communication and Technology
;
傳播與科技學系
傢俱與道具佈置設計師李承峰堅持自我信念，賦予老舊傢俱新的生命及意義。
先知瑪莉　雨季的聲音
(2016-05-08)
趙廣絜
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Department of Communication and Technology
;
傳播與科技學系
以鏡頭紀錄先知瑪莉《梅雨季》巡迴臺北場。
藝術呈現與突破　蜷川實花
(2016-05-08)
蕭泳
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Department of Communication and Technology
;
傳播與科技學系
簡介蜷川實花的台北首展。