Browsing by Issue Date, starting with "2018-05"

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Cathodoluminescence study of defects in thermal treatment of zinc titanate thin films deposited by a cosputtering process
(2018-05-01)
Chiang, Tun-Yuan
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Tsai, Chien-Huang
;
Huang, Ming-Chao
;
Wen, Hua-Chiang
;
Chou, Wu-Ching
The effects of thermal treatment of polycrystalline ZnO-TiO2 systems on their luminescence emission and phase properties were investigated using ex situ cathodoluminescence and back-scattering electron microscopy. The main features of the spectrum are a blue band at 2.75 eV for the phase of TiO and a complex visible band at 2.18 eV for the phase of ZnO, whose peak intensity depends on the annealing temperature. The spectrum intensity is dominated by the ZnO phase when annealing temperature was 720 degrees C, which is attributed to abnormal grain growth. Competition is observed between the broad band peaked at 2.18 eV and visible band peaked at 2.75 eV as the annealing temperature changed (820 degrees C-920 degrees C). The cathodoluminescence density is gradually governed by the TiO2 phase, and the emission in polychromatic and monochromatic imaging is stronger equally at 920 degrees C. The nucleation of the TiO2 and ZnO grains is present in the backscattering electron images as well.
Motion Sickness Simulation Based on Sensorimotor Control
(2018-05-01)
Hu, Chen-Hui
;
Lin, Wen-Chieh
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資訊工程學系
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Department of Computer Science
Sensorimotor control is an essential mechanism for human motions, from involuntary reflex actions to intentional motor skill learning, such as walking, jumping, and swimming. Humans perform various motions according to different task goals and physiological sensory perception; however, most existing computational approaches for motion simulation and generation rarely consider the effects of human perception. The assumption of perfect perception (i.e., no sensory errors) of existing approaches restricts the generated motion types and makes dynamical reactions less realistic. We propose a general framework for sensorimotor control, integrating a balance controller and a vestibular model, to generate perception-aware motions. By exploiting simulated perception, more natural responses that are closer to human reactions can be generated. For example, motion sickness caused by the impairments in the function of the vestibular system induces postural instability and body sway. Our approach generates physically correct motions and reasonable reactions to external stimuli since the spatial orientation estimation by the vestibular system is essential to preserve balance. We evaluate our framework by demonstrating standing balance on a rotational platform with different angular speeds and duration. The generated motions show that either faster angular speeds or longer rotational duration cause more severe motion sickness. Our results demonstrate that sensorimotor control, integrating human perception and physically-based control, offers considerable potential for providing more human-like behaviors, especially for perceptual illusions of human beings, including visual, proprioceptive, and tactile sensations.
Interactive Sand Art Drawing Using RGB-D Sensor
(2018-05-01)
Wong, Sai-Keung
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Chen, Kai-Min
;
Chen, Ting-Yu
;
資訊工程學系
;
Department of Computer Science
We present an interactive system using one RGB-D sensor, which allows a user to use bare hands to perform sand drawing. Our system supports the common sand drawing functions, such as sand erosion, sand spilling, and sand leaking. To use hands to manipulate the virtual sand, we design four key hand gestures. The idea is that the gesture of one hand controls the drawing actions. The motion and gesture of the other hand control the drawing positions. There are three major steps. First, our system adopts a vision-based bare-hand detection method which computes the hand position and recognizes the hand gestures. Second, the drawing positions and the drawing actions are sent to a sand drawing subsystem. Finally, the subsystem performs the sand drawing actions. Experimental results show that our system enables users to draw a rich variety of sand pictures.
香港客家村落的轉變與延續：以荃灣老圍為例
(國立交通大學客家文化學院, 2018-05)
江玉翠
;
Yuk-chui Kong
荃灣最初乃客家人聚居之地，1898年荃灣人口約三千，大部份是客家人，以漁農業為生。如今荃灣已成一個市鎮，變遷巨大，不再是客家人聚居以漁農業為生的地方。荃灣有不少的客家村落，如海壩村、三棟屋等，但很多客家村落已拆掉或人去樓空，雖然今日老圍仍有原居民居住，也有很多方面發生轉變。從其轉變的過程及原因，窺探客家村落、客家人在荃灣以至香港的變遷，這正就是其研究之價值。老圍村在1649年開村，距今超過350年，是荃灣區最早期有人居住的圍村之一，唯老圍則仍然存在，仍然具有生命力。
臺灣客家研究的典範移轉
(國立交通大學客家文化學院, 2018-05)
蕭新煌
;
Hsin-huang Michael Hsiao
1988年的客家族群運動使客家研究成熟和壯大，並引起後續客家政策、行政、法律的提升，以及傳播、學術機構化的落實。因此，臺灣客家研究的形成和成長，可視為客家運動的直接效應之一，或「後客家運動的現象」。過去15年來，臺灣的客家研究的發展除了逐漸制度化和成熟化外，另一個更具深層意義的發展趨勢，即為典範移轉。本文精選並評析九篇有關臺灣客家研究（學）的相關期刊論文及研究報告做為臺灣客家研究典範移轉各階段的代表。這九篇文章的視野，有助於我們了解臺灣的客家研究範疇改變的脈絡，也可以窺見臺灣客家研究所經歷的四個已浮現的典範移轉，亦即，從「客家在臺灣」到在地化的「臺灣的客家」，從地方主義視角到具社會科學本質的族群研究的族群互動視角，從墾殖史到本土族群政治與政策，以及從與原鄉的比較研究典範轉移到和全球比較的新典範。
Multiple target tracking in occlusion area with interacting object models in urban environments
(2018-05-01)
Chen, Jiun-Fu
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Wang, Chieh-Chih
;
Chou, Cheng-Fu
;
資訊工程學系
;
Department of Computer Science
Multiple target tracking in crowded urban environments is a daunting task. High crowdedness complicates motion modeling, and occlusion makes tracking difficult as well. Based on the variable-structure multiple -model (VSMM) estimation framework, this paper extends an interacting object tracking (IOT) scheme with occlusion detection and a virtual measurement model for occluded areas. IOT is composed of a scene interaction model and a neighboring object interaction model. The scene interaction model considers the long-term interactions of a moving object and surroundings, and the neighboring object interaction model considers three short-term interactions. With these interacting object models, the motion feature of a moving object can be represented with the weight of each model. A virtual measurement model is proposed to exploit the motion feature with the IOT scheme under occlusion. The proposed approach was validated using a stationary 2D LIDAR. To verify in occlusion, a 3D LIDAR based benchmark system was developed to extract occluded moving segments. The ample experimental results show that the proposed IOT scheme tracks over 57% of occluded moving objects in an urban intersection. (C) 2018 Elsevier B.V. All rights reserved.
Structural and Functional Test Methods for Micro-Electrode-Dot-Array Digital Microfluidic Biochips
(2018-05-01)
Li, Zipeng
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Lai, Kelvin Yi-Tse
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Yu, Po-Hsien
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Chakrabarty, Krishnendu
;
Ho, Tsung-Yi
A digital microfluidic biochip (DMFB) is an attractive platform for immunoassays, point-of-care clinical diagnostics, DNA sequencing, and other laboratory procedures in biochemistry. More recently, DMFBs based on a micro-electrode-dot-array (MEDA) architecture have been proposed, and droplet manipulations on MEDA biochips have also been experimentally demonstrated. In order to ensure robust fluidic operations and high confidence in the outcome of biochemical experiments, MEDA biochips must be adequately tested before they can be used for bioassay execution. This paper presents the first approach for testing of MEDA biochips that include both CMOS circuits and microfluidic components. We first present structural test techniques to evaluate the pass/fail status of each microcell (droplet actuation, droplet maintenance, and droplet sensing) and identify faulty microcells. In order to ensure correct operation of functional units, e.g., mixers and diluters, we also present functional test techniques to address fundamental MEDA operations, such as droplet dispensing, transportation, mixing, and splitting. We evaluate the proposed test methods using simulations as well as experiments for fabricated MEDA biochips.
Energy-Efficient Sensor Censoring for Compressive Distributed Sparse Signal Recovery
(2018-05-01)
Wu, Jwo-Yuh
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Yang, Ming-Hsun
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Wang, Tsang-Yi
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電信工程研究所
;
Institute of Communications Engineering
To strike a balance between energy efficiency and data quality control, this paper proposes a sensor censoring scheme for distributed sparse signal recovery via compressive-sensing-based wireless sensor networks. In the proposed approach, each sensor node employs a sparse sensing vector with known support for data compression, meanwhile enabling making local inference about the unknown support of the sparse signal vector of interest. This naturally leads to a ternary censoring protocol, whereby each sensor: 1) directly transmits the real-valued compressed data, if the sensing vector support is detected to be overlapped with the signal support; 2) sends a one-bit hard decision if empty support overlap is inferred; and 3) keeps silent if the measurement is judged to be uninformative. Our design then aims at minimizing the error probability that empty support overlap is decided but otherwise is true, subject to the constraints on a tolerable false-alarm probability that non-empty support overlap is decided but otherwise is true, and a target censoring rate. We derive a closed-form formula of the optimal censoring rule; a low complexity implementation using bi-section search is also developed. In addition, the average communication cost is analyzed. To aid global signal reconstruction under the proposed censoring framework, we propose a modified l(1)-minimization based algorithm, which exploits certain sparse nature of the hard decision vector received at the fusion center. Analytic performance guarantees, characterized in terms of the restricted isometry property, are also derived. Computer simulations are used to illustrate the performance of the proposed scheme.
Two smooth support vector machines for epsilon-insensitive regression
(2018-05-01)
Gu, Weizhe
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Chen, Wei-Po
;
Ko, Chun-Hsu
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Lee, Yuh-Jye
;
Chen, Jein-Shan
In this paper, we propose two new smooth support vector machines for -insensitive regression. According to these two smooth support vector machines, we construct two systems of smooth equations based on two novel families of smoothing functions, from which we seek the solution to -support vector regression (-SVR). More specifically, using the proposed smoothing functions, we employ the smoothing Newton method to solve the systems of smooth equations. The algorithm is shown to be globally and quadratically convergent without any additional conditions. Numerical comparisons among different values of parameter are also reported.
Synthesis, luminescence and application of BaKYSi2O7:Eu2+ : A new blue-emitting phosphor for near-UV white-light LED
(2018-05-01)
Ray, Sudeshna
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Tadge, Prachi
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Dutta, Somrita
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Chen, T. M.
;
Nair, Govind B.
A series of new silicate phosphors, Ba1-xEuxKYSi2O7 (BKY: Eu2+) (x = 0.005, 0.01, 0.02, 0.05, 0.07) have been synthesized from a water-soluble propylene glycol modified silane (PGMS) based silicon precursor by a solution approach. This phosphor can be efficiently excited by near-UV light and generates a broadband bright blue emission with internal Quantum Efficiency 34%. The detailed crystal structure of monoclinic BKY:Eu2+ was determined from the XRD profile using Rietveld refinement. Band gap was determined from Diffuse Reflectance Spectra using Kubelka Munk function. Steady state and time resolved Photoluminescence measurement as well as the thermal quenching properties of the phosphor have been investigated in detail. A highly efficient broadband blue emission centered lambda(max) similar to 460 nm with a full-width at half-maximum of 72 nm shows very low thermal quenching; 83.2% at 150 degrees C with respect to that measured at room temperature. Moreover, a white LED device has been fabricated by coating the as-synthesized phosphor with a standard red emitting CaAlSiN3:Eu2+ phosphor and a standard green emitting Ba2SiO4:Eu2+ phosphor. The LED device exhibited an excellent color-rendering index CRI of 84.0564 at a correlated color temperature of 3752.4 K with CIE color coordinates of (0.363, 0.293) under a 350 mA forward-bias current. The interesting excitation profile and robust thermal performance reflect the potential application of this phosphor for near UV- LED driven solid state lighting.
Interference of hepatitis B virus dual infection in platelet count recovery in chronic hepatitis C patients with curative antiviral therapy
(2018-05-01)
Huang, Chung-Feng
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Yeh, Ming-Lun
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Huang, Ching-I
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Lin, Zu-Yau
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Chen, Shinn-Cherng
Background and AimHepatitis C virus infection is associated with thrombocytopenia. Thrombocytopenia recovers after viral eradication. The current study explored the rate and factors associated with platelet (PLT) recovery, which may represent the degree of liver fibrosis regression. MethodsA total of 466 patients who achieved a sustained virological response were enrolled to compare the PLT change after a mean follow-up period of 85.5months (range 12-163months). ResultsPlatelet counts increased significantly after achieving sustained virological response (from 16655x10(3) to 201 +/- 61x10(3)u/L, P<0.001). The median PLT count increment was 5.03x10(3)u/L per year. Logistic regression analysis revealed that factors associated with slow PLT count recovery were high pretreatment PLT counts (odds ratio [OR]/ 95% confidence intervals [CI]: 0.992/0.989-0.996, P<0.001) and hepatitis B virus (HBV) co-infection (OR/CI: 0.416/0.220-0.785, P=0.007). High PLT counts were the only factor associated with slow PLT recovery in patients with mild liver disease (F0-2) (OR/CI: 0.992/0.987-0.996, P<0.001). On the other hand, HBV co-infection was the only factor associated with slow PLT recovery in patients with advanced fibrosis (OR/CI: 0.207/0.054-0.789, P=0.02). Linear regression analysis of factors correlated to the delta PLT count change per year in patients with F0-2 included pretreatment white blood cell (: -0.001; CI: -0.002-0.000; P=0.01) and pretreatment PLT counts (: -0.037; CI: -0.061 to -0.013; P=0.003). HBsAg seropositivity was the only factor correlated to the delta PLT count change per year (: -10.193; CI: -16.752-3.635; P=0.003) among patients with F3-4. ConclusionsPlatelet counts recovered after hepatitis C virus eradication. HBV dual infection disrupted PLT count recovery, especially in CHC patients with advanced liver disease.
Femtosecond laser melting of silver nanoparticles: comparison of model simulations and experimental results
(2018-05-01)
Cheng, Chung-Wei
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Chang, Chin-Lun
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Chen, Jinn-Kuen
;
Wang, Ben
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機械工程學系
Ultrafast laser-induced melting of silver nanoparticles (NPs) using a femtosecond laser pulse is investigated both theoretically and experimentally. The sintered Ag structure fabricated from printed Ag NP ink using femtosecond laser (1064 nm, 300 fs) irradiation is experimentally studied. A two-temperature model with dynamic optical properties and particle size effects on the melting temperature of Ag NPs is considered. The rapid phase change model is incorporated to simulate the Ag NPs' ultrafast laser-induced melting process, and a multi-shot melting threshold fluence predicted from the simulated single-shot melting threshold is developed.
The Effect of Oxygen Vacancy Concentration on Indium Gallium Oxide Solar Blind Photodetector
(2018-05-01)
Chen, Kuan-Yu
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Hsu, Ching-Chien
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Yu, Hsin-Chieh
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Peng, Yu-Ming
;
Yang, Chih-Chiang
In this paper, amorphous indium-gallium-oxide solar-blind metal-semiconductor-metal photodetectors were fabricated by using co-sputtering method. Three samples with different oxygen concentrations, namely, sample A without oxygen, sample B with 2% oxygen concentration, and sample C with 4% oxygen concentration, were investigated. The applied bias was 5 V during device characterization. The ultraviolet (UV)-to-visible rejection ratios were 39, 9.9 x 10(3), and 1.1 x 10(5) for samples A, B, and C, respectively. The dynamic responses of the decay times were 5.79/52.12 s, 1.96/30.49 s, and 0.02/0.75 s for samples A, B, and C, respectively. In summary, the 4% oxygen concentration sample exhibited excellent UV-to-visible rejection ratio and superior decay time.
Room-temperature-operated organic-based acetone gas sensor for breath analysis
(2018-05-01)
Chuang, Ming-Yen
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Lin, Yu-Ting
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Tung, Ting-Wei
;
Chang, Liang-Yu
;
Zan, Hsiao-Wen
The major merits of organic-based sensors include their low cost, room-temperature operation, and small size. However, their sensitivity and selectivity are concerning, especially in the application of breath analysis. In this work, organic-based sensors were developed based on cylindrical nano-pore structures, which enhanced the sensitivity down to ppb levels. The sensing performance was demonstrated both in pure nitrogen and ambient air. The sensor constructed with poly[(9,9-dioctylfluoreny1-2,7-diy1)-co-(4,41(N-(4-sec-butylphenyl)diphenylamine)] (TFB) exhibited a 5% sensing response to 300 ppb of acetone in ambient air. In addition, the sensor's response to other major breath components, including nitric oxide, ethanol, carbon dioxide, and ammonia, was also established. The results showed that the TFB sensor also exhibited a good response to ammonia. Therefore, a humidification tube was designed as an ammonia filter to improve selectivity. The concept of integrating a highly sensitive sensor with a customized sensing system shows promise for medical applications. (C) 2018 Elsevier B.V. All rights reserved.
Highly Sensitive and Optically Transparent Resistive Pressure Sensors Based on a Graphene/Polyaniline-Embedded PVB Film
(2018-05-01)
Liu, Shi-Yu
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Lian, Lu
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Pan, Jin
;
Lu, Jian-Gang
;
Shieh, Han-Ping D.
The development of a facile, low-temperature, and low-cost method to fabricate highly sensitive and optically transparent resistive pressure sensors remains a challenge. In this paper, a graphene/polyaniline-embedded polyvinyl butyral (GPANI-PVB) composite film is employed as the active layer in a resistive pressure sensor; this film is ultrathin, highly sensitive, optically transparent, anisotropically conductive, highly durable, highly flexible, and bending insensitive. A flexible touch panel based on the GPANI-PVB composite film is fabricated using a facile process, which supports multitouch and multilevel pressure detection. The GPANI-PVB composite film offers great potential for applications in flexible and transparent interactive electronic devices.
Mitral valve repair versus replacement in patients with ischemic mitral regurgitation
(2018-05-01)
Lee, Meng-Lin
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Chen, Thay-Hsiung
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Huang, Hsien-Da
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Hou, Shaw-Min
;
生物資訊及系統生物研究所
Background: The optimal management of ischemic mitral regurgitation (IMR) is controversial. The aim of this study was to examine our eight years' experience of surgical treatment in patients with IMR, and to compare outcomes of mitral valve repair versus replacement with concomitant coronary artery bypass grafting (CABG). Methods: A retrospective, observational, cohort study was undertaken to collect data on consecutive patients with IMR and coronary artery disease who received CABG and mitral valve surgery in our hospital between January 2008 and December 2015. Basic patient characteristics, operative data, and postoperative clinical outcomes were examined. Results: The series included 22 consecutive patients (21 male; 1 female). The mean age was 62.1 +/- 11.4 years old. The mean preoperative left ventricular ejection fraction (LVEF) was 33.4%+/- 15.4%. The mean cardiopulmonary bypass (CPB) time was 165.4 +/- 38.4 minutes, and the mean aortic cross clamp time was 113.8 +/- 33.6 minutes. Eighteen patients underwent CABG plus mitral valve repair, and four patients underwent CABG plus mitral valve replacement (MVR). There were three early in-hospital mortalities: two in the mitral valve repair group, and one in the replacement group. The follow-up was complete in all patients, with a mean follow-up duration of 3.1 +/- 2.3 years. The mean last LVEF was 35.3%+/- 17.7%. There were 2 late mortalities. Both were from the repair group. The overall late survival rate was 81.6%, with 83.0% in the repair group and 75.0% in the replacement group. In patients with echocardiography follow-up of more than or equal to 1 year duration, the residual or recurrent mitral regurgitation rates were 0.0% in the replacement group and 57.1% in the repair group. One patient in the repair group later underwent MVR due to severe regurgitation postoperatively. Conclusions: Our preliminary findings showed that the surgical outcome of mitral valve repair might be comparable to that of MVR in terms of early mortality and long-term survival. However, mitral valve repair was associated with a higher residual or recurrent mitral regurgitation rate. According to the latest literature, the role of MVR can justifiably be indicated for severe IMR. As for moderate IMR, CABG alone without mitral valve intervention may provide similar clinical outcomes.
Structural basis for overhang excision and terminal unwinding of DNA duplexes by TREX1
(2018-05-01)
Huang, Kuan-Wei
;
Liu, Tung-Chang
;
Liang, Ruei-Yue
;
Chu, Lee-Ya
;
Cheng, Hiu-Lo
Three prime repair exonuciease 1 (TREX1) is an essential exonuclease in mammalian cells, and numerous in vivo and in vitro data evidenced its participation in immunity regulation and in genotoxicity remediation. In these very complicated cellular functions, the molecular mechanisms by which duplex DNA substrates are processed are mostly elusive because of the lack of structure information. Here, we report multiple crystal structures of TREX1 complexed with various substrates to provide the structure basis for overhang excision and terminal unwinding of DNA duplexes. The substrates were designed to mimic the intermediate structural DNAs involved in various repair pathways. The results showed that the Leu24Pro25-Ser26 cluster of TREX1 served to cap the nonscissile 5'-end of the DNA for precise removal of the short 3'-overhang in L- and Y-structural DNA or to wedge into the double-stranded region for further digestion along the duplex. Biochemical assays were also conducted to demonstrate that TREX1 can indeed degrade double-stranded DNA (dsDNA) to a full extent. Overall, this study provided unprecedented knowledge at the molecular level on the enzymatic substrate processing involved in prevention of immune activation and in responses to genotoxic stresses. For example, Arg128, whose mutation in TREX1 was linked to a disease state, were shown to exhibit consistent interaction patterns with the nonscissile strand in all of the structures we solved. Such structure basis is expected to play an indispensable role in elucidating the functional activities of TREX1 at the cellular level and in vivo.
Manifesting the connection between topological structures of quantum stationary coherent states and bundles of classical Lissajous orbits
(2018-05-01)
Chen, Y. F.
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Hsieh, Y. H.
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Tung, J. C.
;
Liang, H. C.
;
Huang, K. F.
Quantum stationary coherent states with spatial intensities localized on Lissajous orbits are theoretically explored by taking the inverse Fourier transform of the time-dependent coherent state. It is analytically verified that the stationary coherent state can be expressed as an integral of the Gaussian wave packet over the classical periodic orbit. With the derived integral, the phase singularities of the stationary coherent state can be precisely manifested from low-order to extremely high-order states. It is found that the phase singularities near the cross-point of the Lissajous orbits are generally arranged as rhombic vortex arrays. Finally, the stationary coherent states can be used as a basis to manifest the connection between topological structures of quantum eigenstates and bundles of classical Lissajous orbits. Copyright (C) EPLA, 2018
國小四年級客語沉浸教學對學童客語聽說能力的影響
(國立交通大學客家文化學院, 2018-05)
張瑞菊
;
Jui-chu Chang
行政院客家委員會的研究調查顯示客語瀕臨危機，必須由政府與民間推動客語保存，否則可能消失。自民國96年屏東縣客家事務處與學者規劃實施由幼兒至國小一年級的客語沉浸式教學（Hakka language immersion programs），兒童的客語聽說能力能明顯提升，且不影響其各領域課程的學習。為能延續國小學童對於客語的學習與應用，建成客語於國小復振的脈絡，研究者參考其客語沉浸式教學的原則與模式，延伸實施於國民小學四年級學生，獲致實驗班學生客語聽說能力明顯優於對照班的結果，從而應用Arbib（2011）的基模理論（Schema Theory），探討客語沉浸式教學能提升國小四年級學生客語聽說能力的因素，提出客語沉浸式教學延伸實施及強化語言學用、復振的結論及相關建議。
Investor sentiment and evaporating liquidity during the financial crisis
(2018-05-01)
Chiu, Junmao
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Chung, Huimin
;
Ho, Keng-Yu
;
Wu, Chih-Chiang
;
資訊管理與財務金融系註：原資管所+財金所
This study examines how investor sentiment affected equity liquidity and trading behavior during the financial crisis of 2007-2008. Using intraday data on equity index and financial ETFs, we show significant asymmetric response to investor sentiment on quoted spread, market depth, asymmetric depth, and net buying pressure. We also document that funding constraints can further increase the asymmetric impact of investor sentiment on liquidity and trading behavior. Our results can be explained by the psychological bias of negativity and help investors and risk management practitioners comprehensively understand why and how the evaporation of liquidity accelerates during the financial crisis.