Browsing by Issue Date, starting with "2018-11-01"

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Multiple Reflection Analysis of TDR Signal for Complex Dielectric Spectroscopy
(2018-11-01)
Lin, Chih-Ping
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Ngui, Yin Jeh
;
Lin, Chun-Hung
;
交大名義發表
;
National Chiao Tung University
Most dielectric spectroscopy techniques require careful system calibration, tedious measurement, specially designed probes, precise input source, and some even involved complicated inversion models. This paper proposed a rapid, robust, and model-free multiple reflection analysis (MRA) of time-domain reflectometry (TDR) signals to measure the complex dielectric permittivity (CDP) spectrum. The key to MRA approach is to decompose the first top reflection and the subsequent multiple reflections from TDR signal and to compare their spectral ratio (MRA ratio). This ratio was theoretically derived from the transmission line theory and found to be independent of source function and impedance mismatches in the leading sections. Based on this theoretical formulation, the CDP spectrum can be uniquely inverted from the measured MRA ratio through optimization and an iterated initial guess method. Numerical evaluations and experimental verifications had proven that MRA is a reliable algorithm for measuring CDP spectrum covering 10 MHz-I CHz. Factors influencing the reliable frequency region were discussed and recommendations on enhancing CDP measurement was proposed for highly dispersive materials. The MRA approach enables dielectric spectroscopy to be conveniently conducted in both laboratory and field, without complicated system setup and calibration.
Depth-dependent atomic valence determination by synchrotron techniques
(2018-11-01)
Trappen, Robbyn
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Zhou, Jinling
;
Vu Thanh Tra
;
Huang, Chih-Yeh
;
Dong, Shuai
The properties of many materials can be strongly affected by the atomic valence of the contained individual elements, which may vary at surfaces and other interfaces. These variations can have a critical impact on material performance in applications. A non-destructive method for the determination of layer-by-layer atomic valence as a function of material thickness is presented for La0.7Sr0.3MnO3 (LSMO) thin films. The method utilizes a combination of bulk- and surface-sensitive X-ray absorption spectroscopy (XAS) detection modes; here, the modes are fluorescence yield and surface-sensitive total electron yield. The weighted-average Mn atomic valence as measured from the two modes are simultaneously fitted using a model for the layer-by-layer variation of valence based on theoretical model Hamiltonian calculations. Using this model, the Mn valence profile in LSMO thin film is extracted and the valence within each layer is determined to within an uncertainty of a few percent. The approach presented here could be used to study the layer-dependent valence in other systems or extended to different properties of materials such as magnetism.
Ni/NiO/HfO2 Core/Multishell Nanowire ReRAM Devices with Excellent Resistive Switching Properties
(2018-11-01)
Huang, Ting-Kai
;
Chen, Jui-Yuan
;
Ting, Yi-Hsin
;
Wu, Wen-Wei
;
交大名義發表
Resistive random-access memory (ReRAM) is one of the most promising types of nonvolatile memory because it has several important advantages, for example, a simple metal-insulator-metal structure, fast operating speed, high endurance, high retention, and low energy consumption. However, the reliability of ReRAM nanodevices is not persistent, and the complete switching mechanism is not fully understood. In this study, a unique 1D Ni/NiO/HfO2 core/multishell ReRAM nanodevice is designed and fabricated. The different properties, including the electrical characteristics, surface morphology, and elemental distribution, are systematically investigated. The Ni/NiO/HfO2 heterostructure nanowire ReRAM device exhibits excellent electrical characteristics and resistive switching properties. It is remarkable that the endurance could be maintained up to 200 cycles, which is extremely good for a 1D ReRAM device. Additionally, a focused-ion beam technique is used to prepare samples for subsequent transmission electron microscopic (TEM) observation. From the TEM analysis, the position of the conducting filaments is verified and the elemental composition of the conducting filaments is confirmed. The migration of hafnium ions forms the conducting filaments between the HfO2 layer and Ni core, resulting in the switching characteristic. The study enriches the understanding of the mechanism and provides a design to enhance the resistive switching properties of ReRAM nanodevices.
國立陽明大學牙醫校友總會第十七屆理監事組織表
(國立陽明大學牙醫校友會, 2018-11)
Structural and electrical properties analysis of InAlGaN/GaN heterostructures grown at elevated temperatures by MOCVD
(2018-11-01)
Lumbantoruan, Franky
;
Zheng, Xia-Xi
;
Huang, Jian-Hao
;
Huang, Ren-Yao
;
Mangasa, Firman
We report the effects of the growth temperature on the structural and electrical properties of the InAlGaN/GaN heterostructures grown on c-plane sapphire substrates. X-ray Photoelectron Spectroscopy and Atomic Force Microscopy measurements results indicate that the InAlGaN layer properties is strongly dependent on the growth temperature. It is observed that the Gallium incorporation increases with the increase of the growth temperature. Meanwhile, the surface roughness decreases from 0.49 nm to 0.34 nm with the increase of growth temperature. The variation of structural properties, composition and surface morphology influences the transport properties of the InAlGaN/GaN heterostructures. High 2DEG electron density, low sheet resistance and good C-V response with a steep slope for InAlGaN/GaN HEMT were achieved at an optimized growth temperature window between 900 degrees C and 950 degrees C.
陽明大學牙醫校友會南區分會會長的話
(國立陽明大學牙醫校友會, 2018-11)
侯冠宇
Two-tier dynamic load balancing in SDN-enabled Wi-Fi networks
(2018-11-01)
Lin, Ying-Dar
;
Wang, Chih Chiang
;
Lu, Yi-Jen
;
Lai, Yuan-Cheng
;
Yang, Hsi-Chang
This work proposes a Software Defined Networking (SDN) solution to address Wi-Fi congestion due to an unevenly distributed load among access points (APs). The conventional methods generally let client stations learn of APs' load status and select APs distributively. However, such a client-driven approach lacks a global view to make precise load balancing decisions and may result in repeated changes in client-AP association. Although several studies proposed more efficient network-controlled methods to carry out Wi-Fi load balancing, some of them are distributed methods incurring excessive message exchange among customized APs, while the rest centralized methods are found to burden the central controller with unnecessary AP association decisions. In contrast, our solution adopts standardized OpenFlow protocol and SDN controller technology to Wi-Fi networks, organizing the SDN controller and the APs into a two-tier architecture so that the controller can evaluate the degree of load balancing among the APs and decide up to which load level the APs can accept association requests without consulting the controller. From our experiment results, our solution improves Wi-Fi's load balancing degree by 34-41%, and yields an improvement of 28-36% in Wi-Fi's re-association time over generic centralized load balancing methods with positive control.
試論閩西客家博物館的原鄉意象與客家內涵
(國立交通大學客家文化學院, 2018-11)
黃信洋
;
Shin-yang Huang
本文共分成五個部分：第一部分討論客家文化博物館聯盟在中國的出現與效應；第二部分討論中國的博物館以及贛、閩、粵邊區的客家博物館，主要探討的是中國一地具有廣義意涵的客家博物館；第三部分討論中國的客家博物館的展示主軸與客家意涵；第四部分討論閩西的客家博物館及其客家意象的詮釋方式；第五部分是結語，討論原鄉、故鄉與家鄉的意涵與展示層面的社會效應，說明客家博物館就好比現代客家族群的帕德嫩神廟，並闡述發展具有學術理性意涵的客家博物館之必要性。
北美客家移民史的重構和整理: 田野考察紀要
(國立交通大學客家文化學院, 2018-11)
李毓中
;
關恆安
;
Yu Chung Lee
;
David Heng An Kuan
本文為筆者受客家委員會客家研究發展中心委託撰寫之《北美洲客家研究計畫》的田野紀錄，此計畫以建置海外客家研究之基礎資料為研究主軸。如標題所示，重點針對於來自世界各地的客家族群移民北美洲的歷史，以及客家族群在美國各大城市所聚集會館、同鄉會之研究。不過基於研究規模的考量，現以最主要的華埠城市，如美國舊金山、洛杉磯、紐約與西雅圖市，以及加拿大維多利亞市作為研究對象，田野紀要將提供未來從事相關研究專家學者參考。2016 年間，研究團隊兩度前往美國、加拿大，以現存客家團體、墓園與檔案館作為研究對象，過程中所蒐集文獻資料將協助研究者能更精確尋找客家移民與檔案，藉此重構消失的北美洲客家移民史。
Methodological considerations in calculating heart rate variability based on wearable device heart rate samples
(2018-11-01)
Chen, Hung-Kai
;
Hu, Yu-Feng
;
Lin, Shien-Fong
;
交大名義發表
;
電機工程學系
Heart rate variability (HRV) analysis has recently been incorporated into wearable device application. The data source of HRV is the time series of heart beat intervals extracted from electrocardiogram or photoplethysmogram. These intervals are non-uniformly sampled signals and not suitable for spectral HRV analysis, which usually uses uniformly resampled heart beat intervals before calculating the spectral domain parameters. Such a practice is not applicable to heart rate data obtained from wearable devices that usually display and export the beat per minute (BPM) time series data at 1 Hz. The preferred resampling rate to calculate spectral domain parameters is 4 Hz. We compare the spectral HRV results with the 1 Hz and 4 Hz resampling rates in order to validate the use of 1 Hz resampled-RRI data to represent wearable devices BPM time series data for HRV analysis. Our results show that, using a specific combination of signal processing techniques, the lowest mean relative error in spectral domain parameters of normalized low-frequency power (LFnu), normalized high-frequency power (HFnu) and the ratio of normalized low-frequency power to normalized high-frequency power (LFnu/HFnu) between 1 Hz and 4 Hz are 3.7%, 15.3% and 16.4%, respectively. We conclude that using the heart rate data sampled at 1 Hz produces a reasonable estimation of sympathetic activity but a poor estimation of parasympathetic activity.
當代臺灣客家人客語流失的影響因素之探討
(國立交通大學客家文化學院, 2018-11)
王甫昌
;
彭佳玲
;
Fu-chang Wang
;
Jia-ling Peng
本文透過2004 年、2011 年、及2016 年三次全國客家人口與語言調查的資料，分析不同出生世代臺灣客家人客語能力的變化。本文指出三個客語傳承重大斷裂點發生的世代以及結構性因素的影響。第一次重要的世代斷裂，出現在1970 年代出生者，主要是因為電視媒體普遍化的影響。第二次的斷裂則是發生在1980 年代出生者，主因是越來越多的客家人離開客家人聚居地，進入族群混居地區。第三次的斷裂，則是發生在1990 年代以後出生者，新的影響因素，則是此一世代有相當高比例是父母親為客家人與非客家人的通婚。除了這些結構性因素的影響外，結論中也討論其他個人性或家庭內因素的影響。
Escherichia coli as a host for metabolic engineering
(2018-11-01)
Pontrelli, Sammy
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Chiu, Tsan-Yu
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Lan, Ethan I.
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Chen, Frederic Y. -H.
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Chang, Peiching
Over the past century, Escherichia coli has become one of the best studied organisms on earth. Features such as genetic tractability, favorable growth conditions, well characterized biochemistry and physiology, and availability of versatile genetic manipulation tools make E. coli an ideal platform host for development of industrially viable productions. In this review, we discuss the physiological attributes of E. coli that are most relevant for metabolic engineering, as well as emerging techniques that enable efficient phenotype construction. Further, we summarize the large number of native and non-native products that have been synthesized by E. coli, and address some of the future challenges in broadening substrate range and fighting phage infection.
Theoretical developments and clinical experiments of measuring blood flow volume (BFV) at arteriovenous fistula (AVF) using a photoplethysmography (PPG) sensor
(2018-11-01)
Chiang, Pei-Yu
;
Chao, Paul C. -P.
;
Yang, Chih-Yu
;
Tarng, Der-Cherng
;
電子工程學系及電子研究所
A new theoretical developments of measuring blood flow volume at arteriovenous fistula (AVF) using a photoplethysmography (PPG) sensor is presented in this work. The mathematical equation is derived under the practical perspective, aiming at applying to small-size, portable, inexpensive and easy-to-use PPG sensor, in order to replace bulky, expensive Doppler machines which is the commonly used instruments for accessing AVF noninvasively nowadays. Furthermore, a new, portable and wireless PPG sensor with ambient light compensation and motion artifact detection, is designed for performing clinical validation of the proposed equation. After neural network calibration with the gold standard, dilution concentration sensor, the experiment result reveals that the PPG sensors implementing the proposed equation successfully achieve much higher correlation (R-2=0.8064) and much lower error (RMSE=171.68ml/min, MAPE=15.84%) compared to the commercial Doppler machine and other previous works.
A Hardware-Scalable DSP Architecture for Beam Selection in mm-Wave MU-MIMO Systems
(2018-11-01)
Yeh, Chun-Yu
;
Chu, Ting-Chung
;
Chen, Chiao-En
;
Yang, Chia-Hsiang
;
電子工程學系及電子研究所
Millimeter-wave (mm-Wave) communication, operating from 30- to 300-GHz bands with wider available spectrum, has now emerged as a promising solution for future wireless systems. To reduce the hardware complexity of mm-Wave transceivers, beam-selection techniques combined with beamspace multiple-input multiple-output (MIMO) communications have been proposed in the literature. In such a system, beam selection is performed to exploit the near-sparse nature in the mm-Wave channel and, hence, is crucial to the system performance. This paper presents the world's first digital signal processing (DSP) architecture design for beam selection operation in an mm-Wave multi-user MIMO system. A computationally efficient beam-selection algorithm is first presented. Based on the proposed algorithm, a hardware-scalable beam selection processor is implemented using coordinate rotation digital computers arithmetic. To establish the validity of the concept, the proposed processor is implemented in a 40-nm CMOS technology, integrating 360k logic gates in an area of 0.5625 mm(2), while dissipating 44 mW at 266 MHz in an MU-MIMO system with 16 beams and 8 users.
A new multi-mode multi-input-multi-output (MIMO) converter in an efficient low-voltage energy harvesting system for a gas sensor
(2018-11-01)
Yu, Ming-Hung
;
Chao, Paul C. -P.
;
電子工程學系及電子研究所
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電控工程研究所
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Department of Electronics Engineering and Institute of Electronics
This paper presents a new multi-mode multi-input-multi-output (MIMO) converter with a battery for operating an energy harvesting (EH) system for gas sensors. In this EH system, the MIMO converter has a single DC-DC structure with multiple inputs and outputs. The converter is designed and tuned to harvest ambient light energy from a photovoltaic module, and it then provides regulated power at biases of 3.3 and 5V to charge the battery and/or to drive a gas sensor. The battery serves as a load to be charged by the MIMO or as a power source when the ambient light energy is insufficient to drive the gas sensor. For regulating the DC-DC converter, maximum power point tracking is implemented for each power path from inputs and outputs. The proposed MIMO converter has the least number of switches among existing converters. Experimental results reveal that the MIMO converter exhibits a high efficiency of 89.73% for a large power throughput of 0.9W for a gas sensor.
Hyperfine analysis of the microwave spectrum of the vinylthio radical, CH2CHS
(2018-11-01)
Nakajima, Masakazu
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Tokumasu, Takanobu
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Sumiyoshi, Yoshihiro
;
Endo, Yasuki
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應用化學系
Measurement of pure rotational transitions for the vinylthio radical, CH2CHS, previously observed by Fourier-transform microwave spectroscopy (Nakajima et al., 2007), are extended to a number of fine and hyperfine component lines split by the unpaired electron spin and the three non-equivalent protons. All the measured transition frequencies have been analyzed by a Hamiltonian for doublet asymmetric top molecules with hyperfine interaction terms for three nuclear spins, yielding precise molecular constants of CH2CHS in the ground state. Discussions on the electronic structure of CH2CHS are given based on the determined molecular constants. (C) 2018 Elsevier Inc. All rights reserved.
Towards maximizing the sensing accuracy of an cuffless, optical blood pressure sensor using a high-order front-end filter
(2018-11-01)
Kao, Yung-Hua
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Chao, Paul C. -P.
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Wey, Chin-Long
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
A high-order filter as part of an analog front-end circuit for an optical, cuffless photoplethysmography (PPG) sensor is developed herein to maximize the sensing accuracy of measured blood pressures (BPs). The BP device consists physically of light emitting diodes and photo-diodes (PDs) to sense the dynamic change of intravascular blood volume based on the known principle of PPG and then calculate the BP based on reflective pule transient time in a PPG signal. The photoplethysmography (PPG) signal acquired by the PDs are expected to be processed by an excellent front-end circuitry to reduce its noise and DC offset but without much distortion to obtain accurate BP prediction. This front-end is accomplished herein by a transimpedance amplifier, a critical high-order band-pass filter and a programmable gain amplifier, which is followed by microprocessor and a wireless module. The band-pass filter is optimized with a passband from 0.2 to 7.2Hz, where the low-pass is in a 4th order while the high-pass is in 2nd order. The low-pass is designed for reducing noise including those due to ambient lighting, while the high-pass is for reducing DC drifting caused mainly by breathing and/or subject slow motion. 46 subjects were tested with the designed high-order filters in comparison with reference device. The advantages of employing high-order low-pass filter versus first-order is clearly seen in experimental data with an accuracy on predicting BP reaching +/- 3mmHg, as stopped to +/- 7mmHg using commonly used first-order filters.
Rapid removal of sulfamethoxazole from simulated water matrix by visible-light responsive iodine and potassium co-doped graphitic carbon nitride photocatalysts
(2018-11-01)
Paragas, Larah Kriselle B.
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de Luna, Mark Daniel G.
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Doong, Ruey-An
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環境工程研究所
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Institute of Environmental Engineering
An environment-friendly iodine and potassium co-doped g-C3N4 (IK-C3N4) photocatalyst was synthesized via the co-pyrolysis of urea and potassium iodate. Various characterization techniques were employed to evaluate the physical, thermal and chemical characteristics of the as-synthesized photo catalyst. Sulfamethoxazole (SMX) was used as a representative antibiotic pollutant. SMX removal by IK-C3N4 photocatalysts exceeded 99% (similar to 23 times higher than that of pure g-C3N4) within 45 min of visible light irradiation. The kinetics of SMX removal was analyzed with respect to solution pH, photocatalyst dosage and initial SMX concentration. Experimental data was found to fit the pseudo-first order kinetics and the Langmuir-Hinshelwood kinetics. The reuse of the photocatalyst up to 3 consecutive photo degradation cycles gave a minimal decline in SMX removal while the structure and the crystallinity of the nanomaterials remained unchanged. Overall, morphology engineering of conventional bulk graphitic carbon nitride can produce highly efficient photocatalysts for the decontamination of antibiotics in the aqueous environment. (C) 2018 Elsevier Ltd. All rights reserved.
老鄧給個說法─告知，千萬不要被告才知
(國立陽明大學牙醫校友會, 2018-11)
鄧政雄
Capacity Results on Multiple-Input Single-Output Wireless Optical Channels
(2018-11-01)
Moser, Stefan M.
;
Wang, Ligong
;
Wigger, Michele
;
電信工程研究所
;
Institute of Communications Engineering
This paper derives upper and lower bounds on the capacity of the multiple-input single-output free-space optical intensity channel with signal-independent additive Gaussian noise subject to both an average-intensity and a peak-intensity constraint. In the limit where the signal-to-noise ratio (SNR) tends to infinity, the asymptotic capacity is specified, while in the limit where the SNR tends to zero, the exact slope of the capacity is given.