Browsing by Issue Date, starting with "2016-10-12"

Now showing 1 - 20 of 16353

Fabrication of Multilayer Borophene on Insulator Structure
(2016-10-12)
Tsai, Hsu-Sheng
;
Hsiao, Ching-Hung
;
Lin, Yu-Pin
;
Chen, Chia-Wei
;
Ouyang, Hao
Cross-Linkable Hole-Transport Materials Improve the Device Performance of Perovskite Light-Emitting Diodes
(2016-10-12)
Huang, Chiung-Fu
;
Keshtov, Mukhamed L.
;
Chen, Fang-Chung
;
光電工程學系
;
Department of Photonics
Hybrid organic/inorganic perovskites are promising candidate materials for use in photovoltaic applications. More recently, they have also become highly attractive as active materials for other optoelectronic devices, including lasers, light-emitting diodes, and photodetectors. Nevertheless, difficulties in forming continuous and uniform films and the existence of a charge-injection barrier between the perovskite layer and the electrodes have hindered the development of high-performance perovskite light-emitting diodes (PeLEDs). In this study, a cross-linked hole-transport layer (HTL) is introduced to improve the hole-injection efficiency of PeLEDs. Furthermore, this layer simultaneously facilitates the formation of smooth perovskite layers, presumably because of the different surface energies. More interestingly, the HTL also exhibits strong solvent effects on the device performance. When the processing solvent for fabricating the HTLs is changed from chlorobenzene to N,N-dimethylformamide (DMF), the perovskite layer becomes more uniform and continuous, leading to better surface coverage and higher device efficiency, presumably because DMF has strong affinity toward the perovskite precursors. The approach presented herein could become a general method for decreasing the hole-injection barrier of PeLEDs and, eventually, lead to higher device performance.
Design and Analysis of an Antenna Control Mechanism for Time Division Duplexing Distributed Antenna Systems Over High-Speed Rail Communications
(2016-10-12)
Wang, Hung-Hsiang
;
Hou, Hsin-An
;
Chen, Jyh-Cheng
;
資訊工程學系
;
電信工程研究所
Distributed antenna system (DAS) has been introduced to overcome high mobility issues and to extend signals into coverage-hole areas in high-speed rail communications system. In this paper, we discuss echo channel effect and define the corresponding criteria in a time division duplexing (TDD) DAS railway communications system. Furthermore, timing drift problem while applying moving antenna selection technique to solve the echo channel effect is illustrated. Compensation algorithms then are proposed. Simulation results show that the proposed techniques can not only solve the interference problem in TDD-DAS but also provide better scalability in system deployment.
Evaluating team performance and the mediating role of customer knowledge development: An absorptiv1 e capacity framework
(2016-10-12)
Lin, Chieh-Peng
;
Yang, Zi-Ting
;
Huang, Her-Ting
;
經營管理研究所
;
Institute of Business and Management
Drawing upon an absorptive capacity framework, this study explains team performance from a mediating perspective of customer knowledge development (CKD), which represents a learning process based on customer interaction. The model is tested using the data of innovation or R&D teams from large high-tech firms in Taiwan. The test results show that competence development (i.e., activities that enhance the diversified skills of team members) and pro-customer empathy (i.e., a transference of customers\' problems and emotions) positively relate to team performance via the full mediation of CKD. The positive relationship between shared cognitive map and CKD is negatively moderated by collectivism. (C) 2016 Elsevier B.V. All rights reserved.
An optical image stabilisation using a droplet manipulation on a liquid crystal and polymer composite film
(2016-10-12)
Wang, Yu-Jen
;
Tsou, Yu-Shih
;
Chen, Ming-Syuan
;
Lin, Yi-Hsin
;
光電工程學系
We demonstrate an image system with an optical image stabilisation using a droplet manipulation on a liquid crystal (LC) and polymer composite film (LCPCF) to reduce motion blur while preserve image quality. Such an image system adopts a liquid lens on an LCPCF and the mechanism is on a basis of droplet movement on LCPCF whose position changes because electrically tunable orientations of LC molecules on the surface of LCPCF. The change of position of the liquid lens compensates the deviation of light as the image system is under a handshake vibration. As a result, the image system under handshake vibrations could keep a clear image. The operating principles are introduced, and the experiments are performed and discussed. The concept in this paper can also be extended to design other optical components for modulating direction of light. [GRAPHICS] .
LWD-TCP complex activates the morning gene CCA1 in Arabidopsis
(2016-10-13)
Wu, Jing-Fen
;
Tsai, Huang-Lung
;
Joanito, Ignasius
;
Wu, Yi-Chen
;
Chang, Chin-Wen
A double-negative feedback loop formed by the morning genes CIRCADIAN CLOCK ASSOCIATED1 (CCA1)/LATE ELONGATED HYPOCOTYL (LHY) and the evening gene TIMING OF CAB EXPRESSION1 (TOC1) contributes to regulation of the circadian clock in Arabidopsis. A 24-h circadian cycle starts with the peak expression of CCA1 at dawn. Although CCA1 is targeted by multiple transcriptional repressors, including PSEUDO-RESPONSE REGULATOR9 (PRR9), PRR7, PRR5 and CCA1 HIKING EXPEDITION (CHE), activators of CCA1 remain elusive. Here we use mathematical modelling to infer a co-activator role for LIGHT-REGULATED WD1 (LWD1) in CCA1 expression. We show that the TEOSINTE BRANCHED 1-CYCLOIDEA-PCF20 (TCP20) and TCP22 proteins act as LWD-interacting transcriptional activators. The concomitant binding of LWD1 and TCP20/TCP22 to the TCP-binding site in the CCA1 promoter activates CCA1. Our study reveals activators of the morning gene CCA1 and provides an action mechanism that ensures elevated expression of CCA1 at dawn to sustain a robust clock.
FourFold Asthma Study (FAST): a study protocol for a randomised controlled trial evaluating the clinical cost-effectiveness of temporarily quadrupling the dose of inhaled steroid to prevent asthma exacerbations
(2016-10-13)
Skeggs, Andrew
;
McKeever, Tricia
;
Duley, Lelia
;
Mitchell, Eleanor
;
Bradshaw, Lucy
Background: Asthma is one of the commonest chronic diseases in the UK. Acute exacerbations of asthma are unpredictable, disruptive and frightening. They cause considerable morbidity and account for a large component of the health service costs of asthma. The widespread use of an asthma self-management plan, designed to encourage disease monitoring and timely intervention, can reduce exacerbations and is, therefore, recommended for all patients with asthma. Unfortunately, the majority of patients are not provided with such a plan. There are a variety of reasons for this but uncertainty about what to include in the plan when asthma control is deteriorating, but before the need for orally administered corticosteroids, is a contributing factor. The aim of this trial is to determine whether an asthma self-management plan, which includes a temporary quadrupling of the dose of inhaled corticosteroid when asthma control starts to deteriorate, reduces asthma exacerbations requiring orally administered corticosteroids or unscheduled health care consultation for asthma. Methods: A multicentre, pragmatic, randomised trial in adults aged over 16 years with a clinical diagnosis of asthma, treated with a licensed dose of inhaled corticosteroid and at least one exacerbation in the previous 12 months requiring treatment with systemic corticosteroids. Participants will be randomised to either a self-management plan, which includes a temporary (maximum of 14 days) fourfold increase in inhaled corticosteroid or the same plan without an increase in inhaled corticosteroid. Participants will be followed up at 6 and 12 months and will attend the clinic for an additional visit if their asthma control deteriorates. The primary outcome is time to first asthma exacerbation, defined as the need for systemic corticosteroids and/or unscheduled health care consultation for asthma. The estimated sample size is 1800 participants. Discussion: The FAST trial is an independent study that has been prioritised and commissioned by the National Institute for Health Research (NIHR) in the United Kingdom. It will provide high-quality evidence to inform clinical decision-making on the role of an asthma self-management plan, which includes a temporary fourfold increase of inhaled corticosteroid, when asthma control starts to deteriorate. The first participant was randomised on 17th May 2013 and recruitment will close on 31 January 2016 with the last patient last visit taking place in January 2017.
Probing the intrinsic optical Bloch-mode emission from a 3D photonic crystal
(2016-10-14)
Hsieh, Mei-Li
;
Bur, James A.
;
Du, Qingguo
;
John, Sajeev
;
Lin, Shawn-Yu
We report experimental observation of intrinsic Bloch-mode emission from a 3D tungsten photonic crystal at low thermal excitation. After the successful removal of conventional metallic emission (normal emission), it is possible to make an accurate comparison of the Bloch-mode and the normal emission. For all biases, we found that the emission intensity of the Bloch-mode is higher than that of the normal emission. The Bloch-mode emission also exhibits a slower dependence on (h(omega)/k(b)T) than that of the normal emission. The observed higher emission intensity and a different T-dependence is attributed to Bloch-mode assisted emission where emitters have been located into a medium having local density of states different than the isotropic case. Furthermore, our finite-difference time-domain (FDTD) simulation shows the presence of localized spots at metal-air boundaries and corners, having intense electric field. The enhanced plasmonic field and local non-equilibrium could induce a strong thermally stimulated emission and may be the cause of our unusual observation.
Family of graphene-assisted resonant surface optical excitations for terahertz devices
(2016-10-14)
Lin, I-Tan
;
Liu, Jia-Ming
;
Tsai, Hsin-Cheng
;
Wu, Kaung-Hsiung
;
Syu, Jheng-Yuan
The majority of the proposed graphene-based THz devices consist of a metamaterial that can optically interact with graphene. This coupled graphene-metamaterial system gives rise to a family of resonant modes such as the surface plasmon polariton (SPP) modes of graphene, the geometrically induced SPPs, also known as the spoof SPP modes, and the Fabry-Perot (FP) modes. In the literature, these modes are usually considered separately as if each could only exist in one structure. By contrast, in this paper, we show that even in a simple metamaterial structure such as a one-dimensional (1D) metallic slit grating, these modes all exist and can potentially interact with each other. A graphene SPP-based THz device is also fabricated and measured. Despite the high scattering rate, the effective SPP resonances can still be observed and show a consistent trend between the effective frequency and the grating period, as predicted by the theory. We also find that the excitation of the graphene SPP mode is most efficient in the terahertz spectral region due to the Drude conductivity of graphene in this spectral region.
Metallic nanowires and mesoscopic networks on a free surface of superfluid helium and charge-shuttling across the liquid-gas interface
(2016-10-14)
Moroshkin, P.
;
Batulin, R.
;
Leiderer, P.
;
Kono, K.
;
物理研究所
We investigate the motion of electrically charged metallic nano- and microparticles produced by laser ablation in He gas and injected into superfluid helium. In the presence of a vertical static electric field, the particles either perform a repetitive shuttle-like motion transporting the charge across the liquid-gas interface or become trapped under the free surface of liquid He and coalesce into long filaments and complex two-dimensional mesoscopic networks. A classical electrohydrodynamic model is used to describe the motion of charged microparticles in superfluid He. The resulting filaments and networks are analyzed using electron microscopy. It is demonstrated that each filament is in fact composed of a large number of nanowires with a characteristic diameter of order of 10 nm and extremely large aspect ratios.
Induction of unidirectional pi-electron rotations in low-symmetry aromatic ring molecules using two linearly polarized stationary lasers
(2016-10-14)
Mineo, Hirobumi
;
Yamaki, Masahiro
;
Kim, Gap-Sue
;
Teranishi, Yoshiaki
;
Lin, Sheng Hsien
A new laser-control scenario of unidirectional p-electron rotations in a low-symmetry aromatic ring molecule having no degenerate excited states is proposed. This scenario is based on dynamic Stark shifts of two relevant excited states using two linearly polarized stationary lasers. Each laser is set to selectively interact with one of the two electronic states, the lower and higher excited states are shifted up and down with the same rate, respectively, and the two excited states become degenerate at their midpoint. One of the four control parameters of the two lasers, i.e. two frequencies and two intensities, determines the values of all the other parameters. The direction of p-electron rotations, clockwise or counter-clockwise rotation, depends on the sign of the relative phase of the two lasers at the initial time. An analytical expression for the time-dependent expectation value of the rotational angular momentum operator is derived using the rotating wave approximation (RWA). The control scenario depends on the initial condition of the electronic states. The control scenario with the ground state as the initial condition was applied to toluene molecules. The derived time-dependent angular momentum consists of a train of unidirectional angular momentum pulses. The validity of the RWA was checked by numerically solving the time-dependent Schrodinger equation. The simulation results suggest an experimental realization of the induction of unidirectional p-electron rotations in low-symmetry aromatic ring molecules without using any intricate quantum-optimal control procedure. This may open up an effective generation method of ring currents and current-induced magnetic fields in biomolecules such as amino acids having aromatic ring molecules for searching their interactions.
數學需要電腦與新數學基礎
(國立交通大學丘成桐中心, 2016-10-15)
作者:渥伊沃茨基（Vladimir Voevodsky）
;
譯者:周樹靜　
用電腦輔證數學證明才能避免犯錯
數理簡訊科學真理與民生問題的兩難
(國立交通大學丘成桐中心, 2016-10-15)
編輯室
學界大老論辯中國巨型對撞機的未來
數理簡訊微軟想以10 年之功「解決」癌症
(國立交通大學丘成桐中心, 2016-10-15)
編輯室
科學與科技在 21 世紀得到飛躍性的發展，許多科技成就猶如奇蹟，例如電腦程式 AlphaGo 可以漂亮擊敗圍棋高手李世乭，Tesla 電動跑車的性能和續航力毫不遜於汽油跑車。這賦予大眾一種現代科技無所不能的印象，好像沒有什麼是科技辦不到的。
人工智慧專家系統之父
(國立交通大學丘成桐中心, 2016-10-15)
訪問者:克努斯（Donald Knuth）
;
尼爾森（Nils Nilsson）
;
舒泰克（Len Shustek）
;
譯者:林真
專訪涂林獎得主費根堡之生涯回顧
Growth factors-loaded calcium phosphate/polymer hybrid coating with sequential release behavior prepared via electrochemical deposition method
(2016-10-15)
Sar, Jenny I-Chun
;
Lin, Yen-Zhu
;
Lin, Chung-Kwei
;
Liu, Tse-Ying
;
Chen, San-Yuan
In this study, the dicalcium phosphate dehydrate (DCPD)/carboxymethyl hexanoyl chitosan (CHC) hybrid coating layer with sequential release of BMP-2 and TGF-beta 1 was deposited onto Ti6Al4V substrate by electrochemical co-precipitation method. Different concentrations of amphiphatic chitosan derivative (carboxymethyl hexanoyl chitosan, CHC), BMP-2 and TGF-beta 1-loaded PLA microspheres (PLA/TGF-beta 1 MSs) were co-precipitated with the precursor of DCPD. The resulting DCPD/CHC hybrid coating incorporated with BMP-2 and PLA/TGF-beta 1 MSs was designed for improving the osteoconductive and osteoinductive functionalities of Ti6Al4V. FTIR spectroscopy and X-ray diffraction were used to characterize these hybrid coatings. The drug release profile, MC3T3-E1 cell proliferation and alkaline phosphatase activity were used to investigate the functionality of these hybrid coatings. It was found that the incorporation of CHC could be used as a mean to manipulate the release behavior of growth factor from the DCPD/CHC hybrid coating. In addition, the BMP-2- and PLA/TGF-beta 1 MSs-incorporated DCPD/CHC hybrid coating exhibited a sequential release of BMP-2 and TGF-beta 1 during the first and second two weeks, respectively. Importantly, the DCPD/CHC hybrid coating immersed in simulated body fluid gradually transformed to hydroxyapatite phase. Hence, the BMP-2 and PLA/TGF-beta 1 MSs-incorporated DCPD/CHC hybrid coating exhibited the best cell viability and the highest ALP activity after 14 days. The biocompatible hybrid coating with sequential release functionality proposed in the present study can enhance the osseointegration process and possess promising potential for clinical applications in bone implants and tissue engineering. (C) 2016 Elsevier B.V. All rights reserved.
數理人文第十期中英文對照
(國立交通大學丘成桐中心, 2016-10-15)
編輯室
中英名詞對照
專題-人工智慧與AlphaGo 關於深度學習網絡的兩個問題
(國立交通大學丘成桐中心, 2016-10-15)
郭宗杰
;
趙學信　
為什麼需要深度網絡與非線性機制
我們還需要康德的先驗概念嗎？
(國立交通大學丘成桐中心, 2016-10-15)
張復
從心理學和神經科學重新檢視康德的時空概念
輸給AlphaGo之後
(國立交通大學丘成桐中心, 2016-10-15)
楊芬瑩
人機對奕的價值再探索