Browsing by Issue Date, starting with "2019-10-14"

Now showing 1 - 20 of 6665

Triplet vs pi sigma* state mediated N-H dissociation of aniline
(2019-10-14)
Jhang, Wan Ru
;
Lai, Hsin Ying
;
Lin, Yen-Cheng
;
Lee, Chin
;
Lee, Shih-Huang
UV-excited aromatic molecules with N-H/O-H moieties often possess an important nonradiative relaxation pathway, from an optically bright pi pi* state to a dark dissociative pi sigma* state. We apply a new time-selected photofragment translational spectroscopy method to disclose a previously unknown triplet-mediated N-H dissociation of aniline prevented by the multiphoton dissociative ionization in conventional methods. We further determined the branching fractions of aniline dissociated in the pi sigma*, triplet, and ground states at 248 nm. Additionally, we selectively captured the population changes in the singlet and triplet states with ionization from different laser wavelengths, 355 or 266 nm, in time-resolved photoion yields. The combination of experimental data enables us to uniquely determine the relative ionization cross sections of the singlet and triplet states at an ionization laser wavelength of 266 nm and allows us to extensively measure the rate constants of intersystem crossing and the branching fractions at various excitation wavelengths. Published under license by AIP Publishing.
Using logistic regression classification for mitigating high noise-ratio advisement light-panel in rolling-shutter based visible light communications
(2019-10-14)
Chuang, Yu-Cheng
;
Chow, Chi-Wai
;
Liu, Yang
;
Yeh, Chien-Hung
;
Liao, Xin-Lan
We propose and experimentally demonstrated a light-panel and image sensor based visible light communication (VLC) system using machine learning (ML) algorithm. The ML algorithm is compared with the traditional demodulation scheme and the experimental results show that even at very high noise-ratio (NR) light-panel display content, the proposed ML algorithm shows significant bit error rate (BER) improvement. (C) 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement
Detailed mechanism and kinetics of the reaction of Criegee intermediate CH2OO with HCOOH investigated via infrared identification of conformers of hydroperoxymethyl formate and formic acid anhydride
(2019-10-14)
Chung, Chen-An
;
Su, Jou Wei
;
Lee, Yuan-Pern
;
交大名義發表
;
應用化學系
The reaction of Criegee intermediate CH2OO with HCOOH is important in atmospheric chemistry, but its mechanism and kinetics are little investigated. We recorded time-resolved infrared absorption spectra of transient species produced upon irradiation at 308 nm of a flowing mixture of CH2I2/O-2/N-2/HCOOH at 298 K. Bands of CH2OO were observed initially upon irradiation; their decrease was accompanied with the appearance of several bands near 887, 925, 1052, 1115, 1170, 1342, 1391, and 1760 cm(-1), assigned to the absorption of hydroperoxymethyl formate [HC(O)OCH2OOH, HPMF], that decreased in intensity at a later period with the appearance of absorption bands of the anti-conformer of formic acid anhydride [anti-(HCO)(2)O, FAN] near 998, 1101, 1767, and 1821 cm(-1). The main contributions of the infrared absorption of HPMF are from an open-form conformer, but small contributions from the intramolecular hydrogen-bonded conformer that absorbs near 1070, 1170, and 1732 cm(-1) were identified. Observed infrared spectra of both conformers of HPMF and anti-FAN agree satisfactorily with the anharmonic vibrational wavenumbers and IR intensities predicted with the B3LYP/aug-cc-pVTZ method. We derived a rate coefficient for CH2OO + HCOOH to be k = (1.4 +/- 0.3) x 10(-10) cm(3) molecule(-1) s(-1) from formation of HPMF. We found also that anti-FAN was produced mainly from the open-form conformer with rate coefficient k = (1460 +/- 30) s(-1); the intramolecular hydrogen-bonded conformer of HPMF is stable.
A coupled grid based particle and implicit boundary integral method for two-phase flows with insoluble surfactant
(2019-10-15)
Hsu, Shih-Hsuan
;
Chu, Jay
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Lai, Ming-Chih
;
Tsai, Richard
;
應用數學系
We develop a coupled grid based particle and implicit boundary integral method for simulation of three-dimensional interfacial flows with the presence of insoluble surfactant. The grid based particle method (GBPM, Leung and Zhao [20]) tracks the interface by the projection of the neighboring Eulerian grid points and does not require stitching of parameterizations nor body fitted moving meshes. Using this GBPM to represent the interface, the surfactant equation defined on the interface is discretized naturally following a new volumetric constant-along-surface-normal extension approach (Chu and Tsai [4]). We first examine the proposed scheme to solve the convection-diffusion equation for the problems with available analytical solutions. The numerical results demonstrate secondorder accuracy of the scheme. We then perform a series of simulations for interfacial flows with insoluble surfactant. The numerical results agree well with the theory, and are comparable with other numerical works in literature. (C) 2019 Elsevier Inc. All rights reserved.
Energy Harvesting For Wearable Devices: A Review
(2019-10-15)
Chong, Yung-Wey
;
Ismail, Widad
;
Ko, Kwangman
;
Lee, Chen-Yi
;
電子工程學系及電子研究所
In recent years, wearable devices have attracted attention because of their ability to enhance the quality of life. This disruptive technology has helped healthcare professionals with intervening early in chronic diseases, especially amongst independently living patients, and has facilitated real-time monitoring of patients' vital signs remotely. One of the major bottlenecks that hamper the adoption of wearable device is the continuous power supply. Most wearable devices solely depend on battery supply. When the energy stored in the battery is depleted, the operation of wearable devices is affected. To overcome this limitation, efficient energy harvesters for wearable devices are crucial. The paper primarily aims to present a comprehensive classification of different energy sources that can be capitalized to power wearable devices. In addition, this research paper deals with the key challenges that must be considered in the development of autonomous wearable devices for telemedicine applications with a proposed system design for wearable device that uses energy harvesting technology.
Degradation mechanisms of bias stress on nitride-based near-ultraviolet light-emitting diodes in salt water vapor ambient
(2019-10-15)
Chen, Lih-Ren
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Huang, Shen-Che
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Chiu, Jo-Lun
;
Lu, Chien-Cheng
;
Su, Wei-Ming
Degradation mechanisms of nitride-based near-ultraviolet (near-UV) light-emitting diodes (LEDs) were systematically analyzed by applying forward- and reverse-bias stresses to them in a salt water vapor ambient. The surface temperature of the forward-bias stress sample was higher than that of the reverse-bias stress sample. The high temperature of the forward-bias stress sample accelerated the chemical reaction of the device structure with salt water vapors and led to faster degradation. Composition analyses of the sample surface and cross-section were conducted to investigate the failure mechanism. The analyses results indicated that the erosion of the indium-tin-oxide layer enhanced the diffusion of the conducting metal into the LED crystal. The proposed method can effectively characterize the quality of near-UV LEDs in a short duration.
Tape-Stripping Electrochemical Detection of Melanoma
(2019-10-15)
Darvishi, Sorour
;
Pick, Horst
;
Lin, Tzu-En
;
Zhu, Yingdi
;
Li, Xiaoyun
A noninvasive electrochemical melanoma detection approach based on using adhesive tapes for collecting and fixing cells from a suspicious skin area and transferring the cells into a scanning electrochemical microscope (SECM) is presented. The adhesive layer collects the cells reproducibly and keeps them well adhered on the tape during experiments in an electrolyte solution. A melanoma biomarker, here the intracellular enzyme tyrosinase (TYR), was imaged on the tape-collected cells without further cell lysing using antibodies that were labeled with horseradish peroxidase (HRP). The HRP labels catalyzed the oxidation of a dissolved redox-active species, which was detected at a soft microelectrode, gently brushed in contact mode over the tape. The melanoma biomarker was first detected on tape-stripped samples with murine melanoma cells of different concentrations. Thereafter, increasing levels of TYR were recorded in cells that were collected from the skin of melanoma mouse models representing three different stages of tumor growth. Additionally, SECM results of tape-stripped different human melanoma cell lines were confirmed by previous studies based on traditionally fixed and permeabilized cells.
A scalable and accurate distributed traffic generator with Fourier transformed distribution over multiple commodity platforms
(2019-10-15)
Chang, Ching-Hao
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Lin, Ying-Dar
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Lai, Yu-Kuen
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Lai, Yuan-Cheng
;
資訊工程學系
The rapid growth of high-speed computer networks poses a challenge in the design of testing and verification equipment. The hardware-based packet generators that are often used in the verification process are accurate but costly. Software-based packet generators, on the other hand, are relatively low-cost but have a limited performance with low accuracy. This paper proposes a Fourier-based profile decomposition and formulation methodology for a distributed packet generating system, featuring good horizontal scalability and high accuracy. Different from traditional software-based packet generators, this proposed system extracts the traffic components from a specific traffic distribution applying Fourier transformation to generate traffic components. These traffic components are distributed to one or more worker nodes for packet generation, and thus achieving higher aggregated traffic rate in any given distribution. The system design is based on the Data Plane Development Kits (DPDK) framework to maximize the traffic generation performance. The accuracy and performance of the proposed system scale according to the number of worker nodes used. Currently, with multiple CPU cores and five workers, the proposed system can generate aggregated traffic of more than 40 Gbps in a Poisson distribution.
Element Effects on High-Entropy Alloy Vacancy and Heterogeneous Lattice Distortion Subjected to Quasi-equilibrium Heating
(2019-10-15)
Huang, E-Wen
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Chou, Hung-Sheng
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Tu, K. N.
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Hung, Wei-Song
;
Tu-Ngoc Lam
We applied Simmons-Balluffi methods, positron measurements, and neutron diffraction to estimate the vacancy of CoCrFeNi and CoCrFeMnNi high-entropy alloys (HEAs) using Cu as a benchmark. The corresponding formation enthalpies and associated entropies of the HEAs and Cu were calculated. The vacancy-dependent effective free volumes in both CoCrFeNi and CoCrFeMnNi alloys are greater than those in Cu, implying the easier formation of vacancies by lattice structure relaxation of HEAs at elevated temperatures. Spatially resolved synchrotron X-ray measurements revealed different characteristics of CoCrFeNi and CoCrFeMnNi HEAs subjected to quasi-equilibrium conditions at high temperatures. Element-dependent behavior revealed by X-ray fluorescence (XRF) mapping indicates the effect of Mn on the Cantor Alloy.
Characteristics of atomic layer deposition-grown zinc oxide thin film with and without aluminum
(2019-10-15)
Tseng, Ming-Chun
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Wuu, Dong-Sing
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Chen, Chi-Lu
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Lee, Hsin-Ying
;
Chien, Cheng-Yu
Zinc oxide (ZnO) and Al-doped ZnO (AZO) thin films were deposited on glass substrates using atomic layer deposition. The Al composition of the AZO thin films was varied by controlling the Zn:Al cycle ratios. The ZnO and AZO thin films were characterized using atomic force microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and optical measurements. The electrical properties of the ZnO and AZO thin films were influenced by the Zn:Al cycle ratios. The resistivity of the AZO thin film decreased significantly, whereas the carrier concentration increased with the Al composition. As the Zn:Al cycle ratio increased, the AZO thin film achieved an average transmittance of > 85%.
陽明攜手富邦開發「高齡健康風險評估模組」，完善健康促進策略
(國立陽明大學, 2019-10-16)
陽明電子報編輯小組
台灣預計在2025年將邁入超高齡社會，為因應高齡社會帶來的衝擊與潛在風險，陽明與富邦人壽歷時三年，透過大數據蒐集與AI智慧演算...
【冒點兒險系列】我喜歡你，然後呢～關係的邀請與建立
(國立陽明大學, 2019-10-16)
陽明電子報編輯小組
【職涯諮詢服務】
(國立陽明大學, 2019-10-16)
陽明電子報編輯小組
靈光的對話——影像創作工作坊與成果展
(國立陽明大學, 2019-10-16)
陽明電子報編輯小組
九月剛開學，藝文中心的「影像工作坊」立即登場。這次工作坊從9月16日至18日，為期三天，並與策展人古羅文君以及西班牙影像藝術家Mauricio Freyere合作。由Mauricio Freyere指導陽明的學生，於工作坊中學習創意建構，並觀摩藝術家經典創作影片，從中討論及解讀影片語彙與簡潔美學。最後，由學生們完成小組影像作品，並在之後的成果展中呈現。
【10/25與校長有約】
(國立陽明大學, 2019-10-16)
陽明電子報編輯小組
【人機智能與哲學共創工作坊】什麼是資料data？解碼跨域AI創新的動能何在
(國立陽明大學, 2019-10-16)
陽明電子報編輯小組
歡慶20週年，陽明育成中心卓然有成
(國立陽明大學, 2019-10-16)
陽明電子報編輯小組
陽明創新育成中心成立於1999年，是台灣最早以醫學與生物科技為主的專業育成中心，20年來培育的企業備受肯定，是國內獲得「亞洲育...
《小偷家族》（Shoplifters）
(國立陽明大學, 2019-10-16)
黃柏威
;
陽明電子報編輯小組
【2019攜手共創新商機】～榮陽聯合研發成果發表媒合會
(國立陽明大學, 2019-10-16)
陽明電子報編輯小組
2019未來科技突破獎，陽明三位老師獲殊榮
(國立陽明大學, 2019-10-16)
陽明電子報編輯小組
科技部日前公布「2019未來科技突破獎」得獎名單，陽明三位老師以前瞻的創新研發，在超過500位參賽者中脫穎而出，包括：腦科所楊智...