Browsing by Issue Date, starting with "2018-06-01"

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Enhancing the magnetic moment of ferrimagnetic NiCo2O4 via ion irradiation driven oxygen vacancies
(2018-06-01)
Pandey, Parul
;
Bitla, Yugandhar
;
Zschornak, Matthias
;
Wang, Mao
;
Xu, Chi
Ion irradiation has emerged as a powerful tool for the efficient control of uniaxial lattice expansion to fine tune and modulate the otherwise inaccessible complex correlated phases in oxide thin-films. We report the fine tuning of the magnetic moment, ferromagnetic-paramagnetic and metal-insulator transition temperatures in the NiCo2O4 inverse-spinel oxide by creating oxygen deficiencies, employing high energy He-ion irradiation. Tailoring of oxygen vacancies and consequently a uniaxial lattice expansion in the out-of-plane direction drives the system toward the increase of the magnetic moment by two-times in magnitude. The magnetic moment increases with the He-ion irradiation fluence up to 2.5 x 10(16)/cm(2) . Our results are corroborated well by spin-polarized electronic structure calculations with density functional theory and X-ray absorption spectroscopic data, which show peak-height change and energy shift of Co-L-2,L-3 and Ni-L-2,L-3 edges driven by the oxygen vacancies. These results demonstrate a new pathway of tailoring oxygen vacancies via He-ion irradiation, useful for designing new functionalities in other complex oxide thin-films. (C) 2018 Author(s).
Reducing Forming Voltage by Applying Bipolar Incremental Step Pulse Programming in a 1T1R Structure Resistance Random Access Memory
(2018-06-01)
Zheng, Hao-Xuan
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Chang, Ting-Chang
;
Xue, Kan-Hao
;
Su, Yu-Ting
;
Wu, Cheng-Hsien
This letter introduces a method of using bipolarity bias voltages in the forming process to effectively reduce the forming voltage of a one-transistor and one-resistance random access memory device. A bipolar incremental-step-pulse programming process is applied, and a complete operation pulse for the forming process is described. This method reduces forming voltage without any cost to the device performance, and the device maintains good reliability. The likely physical mechanism of this bipolar operation is also presented based on the measured electrical characteristics.
Helicobacter pylori-derived heat shock protein 60 increases the induction of regulatory T-cells associated with persistent infection
(2018-06-01)
Hsu, Wei-Tung
;
Ho, Shu-Yi
;
Jian, Ting-Yan
;
Huang, Han-Ning
;
Lin, Yu-Ling
Local Treg responses are involved in Helicobacter pylori-related inflammation and clinical outcomes after infection, and H. pylori-derived HSP60 (HpHSP60) is an important virulence factor associated with gastric carcinogenesis. This study to investigate the role of HpHSP60 in immunosuppression, particularly with regard to whether it could induce the production of Treg cells. For this purpose, human peripheral blood mononuclear cells (PBMCs) were treated with or without HpHSP60 in the presence of an anti-CD3 mAb to determine the effect of HpHSP60 on cell proliferation. In this report, HpHSP60 decreased the expression of CDK4 to significantly arrest the proliferation of mitogen-stimulated T-cells, which correlated with the induction of Treg cells. Moreover, monocytic cells were essential for the induction of HpHSP60-induced Treg cells via the secretion of IL-10 and TGF-beta after treatment with HpHSP60. Blockage of HpHSP60 with specific monoclonal antibodies significantly reduced the colonization of H. pylori and the expression of Treg cells in vivo. Overall, our results suggest that HpHSP60 could act on macrophages to trigger the expression of IL-10 and TGF-beta, thereby leading to an increase in Treg cells and inhibition of T-cell proliferation.
Storm event-based frequency analysis method
(2018-06-01)
Jun, Changhyun
;
Qin, Xiaosheng
;
Tung, Yeou-Koung
;
De Michele, Carlo
;
防災與水環境研究中心
In this study, a storm event-based frequency analysis method was proposed to mitigate the limitations of conventional rainfall depth-duration-frequency (DDF) analysis. The proposed method takes the number, rainfall depth, and duration of rainstorm events into consideration and is advantageous in estimation of more realistic rainfall quantiles for a given return period. For the purpose of hydraulics design, the rainfall depth thresholds are incorporated to retrieve the rainstorm events for estimating design rainfalls. The proposed method was tested against the observed rainfall data from 1961 to 2010 at Seoul, Korea and the computed rainfall quantiles were compared with those estimated using the conventional frequency analysis method. The study results indicated that the conventional method was likely to overestimate the rainfall quantiles for short rainfall durations. It represented that the conventional method could reflect rainfall characteristics of actual rainstorm events if longer durations (like 24 hours) were considered for estimation of design rainfalls.
樂在桌球50年
(國立陽明大學, 2018-06)
陳恆理
SVM-Based Dynamic Voltage Prediction for Online Thermally Constrained Task Scheduling in 3-D Multicore Processors
(2018-06-01)
Liao, Chien-Hui
;
Wen, Charles H. -P.
;
電機工程學系
;
電信工程研究所
;
Department of Electrical and Computer Engineering
Hotspots occur frequently in 3-Dmulticore processors (3D-MCPs) and they may adversely impact the reliability of the system and its lifetime. We present support-vector-machine (SVM)-based dynamic voltage assignment (SVMDVA) strategy to select voltages among low-power and high-performance operating modes for reducing hotspots and optimizing performance in 3D-MCPs. The proposed SVMDVA can be employed in online, thermally constrained task schedulers. First, we revealed two different thermal regions of 3D-MCPs and extract different key features of these regions. Based on these key features, SVM models are constructed to predict the thermal behavior and the best operation mode of 3D-MCPs during runtime. SVMDVA using SVM models with monitoring workload and temperature behavior can effectively limit the temperature increase in 3D-MCPs. This is extremely important for accurately predicting the thermal behavior and providing the optimum operating condition of 3D-MCPs to achieve the best system performance. Experimental results show that SVMDVA is an effective technique for reducing hotspot occurrences (57.19%) and increasing throughput (25.41%) for 3D-MCPs.
Size-strain separation in diffraction line profile analysis
(2018-06-01)
Scardi, P.
;
Ermrich, M.
;
Fitch, A.
;
Huang, E-Wen
;
Jardin, R.
Separation of size and strain effects on diffraction line profiles has been studied in a round robin involving laboratory instruments and synchrotron radiation beamlines operating with different radiation, optics, detectors and experimental configurations. The studied sample, an extensively ball milled iron alloy powder, provides an ideal test case, as domain size broadening and strain broadening are of comparable size. The high energy available at some synchrotron radiation beamlines provides the best conditions for an accurate analysis of the line profiles, as the size-strain separation clearly benefits from a large number of Bragg peaks in the pattern; high counts, reliable intensity values in low-absorption conditions, smooth background and data collection at different temperatures also support the possibility to include diffuse scattering in the analysis, for the most reliable assessment of the line broadening effect. However, results of the round robin show that good quality information on domain size distribution and microstrain can also be obtained using standard laboratory equipment, even when patterns include relatively few Bragg peaks, provided that the data are of good quality in terms of high counts and low and smooth background.
Formation and characterization of preferred oriented perovskite thin films on single-crystalline substrates
(2018-06-01)
Chen, Lung-Chien
;
Chen, Cheng-Chiang
;
Chang, Sheng Hsiung
;
Lee, Kuan-Lin
;
Tseng, Zong-Liang
Three single-crystalline (Al2O3, GaN/Al2O3 and InAs) substrates are used to assist the formation of crystallographically preferred oriented CH3NH3PbI3 (MAPbI(3)) thin films. The estimation of the lattice mismatch at the MAPbI(3)/substrate interface and water-droplet contact angle experiments indicate that the formation of a preferred oriented MAPbI(3) thin film is induced by the single-crystalline substrate and is insensitive to the surface wettibility of the substrate. Moreover, the experimental results suggest that the lattice mismatch at the MAPbI(3)/single-crystalline semiconductor interface can strongly influence the photovoltaic performance of tandem solar cells.
Cs0.33WO3 compound nanomaterial-incorporated thin film enhances output of thermoelectric conversion in ambient temperature environment
(2018-06-01)
Cheng, Chih-Yi
;
Chen, Guan-Lin
;
Hu, Po-Sheng
;
光電系統研究所
;
照明與能源光電研究所
Cs0.33WO3 nanomaterial absorbs a range of near-infrared (NIR) wavelength spanning 900-2400 nm, of which the main contributor of heat energy may be utilized for electrical generation. In this research, the capability of Cs0.33WO3 nanomaterial in enhancing the output of a thermoelectric (TE) device by trapping the absorbed heat at the hot-side surface of the device is investigated. The material is synthesized through a combination of the processes of co-precipitation and wet nano-grinding, and the characterization of its structural and optical properties was carried out using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and visible-near-infrared absorption spectroscopy. Likewise, the photothermal property of Cs0.33WO3 nanomaterial, in the form of solution or solid film, is assessed to gain better insight into its effects on the electrical output of the TE device, utilizing a laser with wavelength of 808 nm, a solar simulator, and sunlight in ambient environment. Moreover, the photoelectric property of the Cs0.33WO3 nanomaterial-incorporated TE device was evaluated in four different types of weather condition, sunny, sunny with partly cloudy, cloudy, and rainy; and our results indicate that Cs0.33WO3 nanomaterial is capable of enhancing the output of thermoelectric conversion in an ambient environment. In a complete sunny day, when compared with a bare thermoelectric device, the coating of Cs0.33WO3 nanomaterial with concentration of 0.66 wt% demonstrated a rise of 13.1% in the maximal attainable temperature and a corresponding increase of 291% in maximal output voltage.
Orbital resonances of Taiwan's FORMOSAT-2 remote sensing satellite
(2018-06-01)
Lin, Shin-Fa
;
Hwang, Cheinway
;
土木工程學系
;
Department of Civil Engineering
Unlike a typical remote sensing satellite that has a global coverage and non-integral orbital revolutions per day, Taiwan's FORMOSAT-2 (FS-2) satellite has a non-global coverage due to the mission requirements of one-day repeat cycle and daily visit around Taiwan. These orbital characteristics result in an integer number of revolutions a day and orbital resonances caused by certain components of the Earth's gravity field. Orbital flight data indicated amplified variations in the amplitudes of FS-2's Keplerian elements. We use twelve years of orbital observations and maneuver data to analyze the cause of the resonances and explain the differences between the simulated (at the pre-launch stage) and real orbits of FS-2. The differences are quantified using orbital perturbation theories that describe secular and long-period orbital evolutions caused by resonances. The resonance induced orbital rising rate of FS-2 reaches +1.425 m/day, due to the combined (modeled) effect of resonances and atmospheric drags (the relative modeling errors < 10%). The concave shapes in the time-evolution of the longitude of descending node (LonDN) coincide with the positive rates of daily semi-major axis (SMA) change, also caused by resonances. The non-zonal geopotential coefficients causing the resonance effects contributed up to 45% of FS-2's inclination decline. Our retrospective analysis of FS-2's resonant orbit can provide lessons for a remote sensing mission similar to FS-2, especially in the early mission design and planning phase.
Three-dimensional/two-dimensional convertible display based on computer-generated holograms and an amplitude-modulated spatial light modulator
(2018-06-01)
Matoba, Osamu
;
Lin, Wen-Kai
;
Hsiao, Fu-Li
;
Huang, Chi-Yen
;
Lin, Bor-Shyh
A three-dimensional/two-dimensional (3-D/2-D) convertible display was proposed. The display system offers 2-D images via the traditional display technology and offers 3-D images via the computer-generated hologram (CGH) technology. In this system, 2-D and 3-D images are generated from the same amplitude-modulated spatial light modulator (SLM). In the 2-D display mode, the panel displays an amplitude-modulated image and the 2-D image is projected on a polarization-dependent diffuser (PD) screen. In the 3-D display mode, the SLM panel displays CGHs to generate 3-D images. The zero-order diffraction of the amplitude-type CGH will be blocked by a spatial filter (SF), which is designed by a polarizer. Furthermore, a liquid crystal element was employed to modulate the polarization state of the reconstructed light to let the 3-D image quality not to be reduced by the PD. Finally, the proposed system can offer 2-D and 3-D images both clearly. The system suppresses the zero-order diffraction noise of the amplitude-type CGH system successfully. (C) 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)
SOME REMARKS ON BOUNDARY OPERATORS OF BESSEL EXTENSIONS
(2018-06-01)
Goodman, Jesse
;
Spector, Daniel
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應用數學系
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Department of Applied Mathematics
In this paper we study some boundary operators of a class of Bessel-type Littlewood-Paley extensions whose prototype is Delta(x)u(x,y) +(1-2s)(y) (partial derivative u)(partial derivative y)(x,y) + (2)(partial derivative y) (partial derivative 2u)(x,y) = 0 for x is an element of R-d,y > 0, u(x,0) = f(x) for x is an element of R-d. In particular, we show that with a logarithmic scaling one can capture the failure of analyticity of these extensions in the limiting cases s = k is an element of N.
【校友動態】利用針灸處理反射性噁心嘔吐
(國立陽明大學牙醫校友會, 2018-06)
黃逸峰
A 16-Channel CMOS Chopper-Stabilized Analog Front-End ECoG Acquisition Circuit for a Closed-Loop Epileptic Seizure Control System
(2018-06-01)
Wu, Chung-Yu
;
Cheng, Cheng-Hsiang
;
Chen, Zhi-Xin
;
電子工程學系及電子研究所
;
生醫電子轉譯研究中心
In this paper, a 16-channel analog front-end (AFE) electrocorticography signal acquisition circuit for a closed-loop seizure control system is presented. It is composed of 16 input protection circuits, 16 auto-reset chopper-stabilized capacitive-coupled instrumentation amplifiers (AR-CSCCIA) with bandpass filters, 16 programmable transconductance gain amplifiers, a multiplexer, a transimpedance amplifier, and a 128-kS/s 10-bit delta-modulated successive-approximation-register analog-todigital converter (SAR ADC). In closed-loop seizure control system applications, the stimulator shares the same electrode with the AFE amplifier for effective suppression of epileptic seizures. To prevent from overstress in MOS devices caused by high stimulation voltage, an input protection circuit with a high-voltage-tolerant switch is proposed for the AFE amplifier. Moreover, low input-referred noise is achieved by using the chopper modulation technique in the AR-CSCCIA. To reduce the undesired effects of chopper modulation, an improved offset reduction loop is proposed to reduce the output offset generated by input chopper mismatches. The digital ripple reduction loop is also used to reduce the chopper ripple. The fabricated AFE amplifier has 49.1-/59.4-/67.9-dB programmable gain and 2.02-mu Vrms input referred noise in a bandwidth of 0.59-117 Hz. The measured power consumption of the AFE amplifier is 3.26 mu W per channel, and the noise efficiency factor is 3.36. The in vivo animal test has been successfully performed to verify the functions. It is shown that the proposed AFE acquisition circuit is suitable for implantable closed-loop seizure control systems.
Clonal spread of carbapenem-resistant Acinetobacter baumannii across a community hospital and its affiliated long-term care facilities: A cross sectional study
(2018-06-01)
Chen, Chang-Hua
;
Kuo, Han-Yueh
;
Hsu, Po-Jui
;
Chang, Chien-Min
;
Chen, Jiann-Yuan
Background: The global spread of carbapenem-resistant Acinetobacter baumannii (CRAB) is now a public health problem. In Taiwan, the relationship of the CRAB circulation between long-term care facilities (LTCFs) and acute care hospitals remains unclear. Here, we use molecular epidemiologic methods to describe the transmission of CRAB isolates between a community hospital and its affiliated LTCFs. Methods: Subjects localized in eight LTCFs who were not admitted acute care hospitals in recent a year were enrolled in this study. CRAB isolates were collected during June 1, 2015 and December 31, 2015. DNA fingerprinting was performed by repetitive extragenic palindromic sequence-based polymerase chain reaction (Rep-PCR) and multilocus sequence typing (MLST). Multiplex-PCR amplification for the detection of bla(OXA) genes and beta-lactamase genes was performed. Results: Twenty one subjects were enrolled. The major hospital admission diagnoses among the 21 subjects were pneumonia (71.4%). Genotyping of CRAB isolates by Rep-PCR revealed that a major clone, designated as type III, comprised fifteen of 21 (71.4%) isolates taken from 5 LTCFs and one study hospital. The isolates with type III were subtyped by PubMLST into 4 ST types. The most prevalent bla(OXA) genes in these isolates were bla(OXA-23)-like (85.70%, 18/21). Twenty isolates carried bla(SHV). Conclusion: Clonal spread of bla(OXA-23)-carrying CRABs was found around LTCFs and the affiliated hospital. In Taiwan, it is important for the government to focus attention on the importance of identifying and tracing CRAB infections in LTCFs. Copyright (C) 2017, Taiwan Society of Microbiology. Published by Elsevier Taiwan LLC.
Liquid crystal electro-optic modulator based on transparent conductive TiO2/Ag/TiO2 multilayers
(2018-06-01)
Su, Y. C.
;
Chiou, C. C.
;
Marinova, V.
;
Lin, S. H.
;
Dikov, Hr.
In this paper, TiO2/Ag/TiO2 multilayers, deposited by magnetron sputtering technique at room temperature are used as transparent conductive layers for Liquid Crystal (LC) devices fabrication. The measured electro-optical modulation characteristics and phase retardation of LC cell based on TiO2/Ag/TiO2 electrode show improved electro-optic performances in comparison with LC reference cell using commercial Indium Tin Oxide (ITO). Low sheet resistance and high transparency of TiO2/Ag/TiO2 multilayers open a great potential for next generation ITO-free liquid crystals electro-optical modulators.
Orientation Preferences of Interchain Stackings for Poly(3-hexylthiophene) Nanowires Prepared Using Template-Based Wetting Methods
(2018-06-01)
Jeng, Kai-Sheng
;
Chu, Chien-Wei
;
Liu, Chien-Liang
;
Jean, Woan-Mei
;
Chen, Hsin-Lung
Poly(3-hexylthiophene) (P3HT) nanowires have drawn great attention recently because of their unique properties that can be applied to optoelectronic devices such as conjugated polymer solar cells and organic field-effect transistors. There is still an urgent need, however, to study the fabrication and characterization of P3HT nanowires with controllable morphologies and molecular orientations. In this work, feasible routes are presented to fabricate P3HT nanowires using the solution wetting template method and the solvent-annealing-induced nanowetting in template (SAINT) method. The morphologies and chemical compositions of the P3HT nanowires prepared using these two methods are confirmed by scanning electron microscopy, transmission electron microscopy (TEM), and Raman spectroscopy. From the ultraviolet-visible spectroscopy and wide-angle X-ray scattering results, it is concluded that the degrees of the crystallinity and the orientation preferences of interchain stackings along the pore axis for the P3HT nanowires prepared by the SAINT method are higher than those prepared by the solution wetting template method.
Analytical and experimental studies on building mass damper system with semi-active control device
(2018-06-01)
Liu, Yu-Fang
;
Lin, Tzu-Kang
;
Chang, Kuo-Chun
;
土木工程學系
;
Department of Civil Engineering
A concept of improving an optimum building mass damper (OBMD) system through a semi-active control method for enhancing the efficiency of controlling structural responses is proposed. The proposed concept entails replacing the passive fluid viscous dampers used in an OBMD system with semi-active magnetorheological dampers, thus transforming the system into a novel semi-active OBMD (SOBMD) system for better seismic performance. A numerical model based on the Bouc-Wen model with the interpolation technique was established to represent the behavior of the semi-active magnetorheological dampers. The SOBMD system was then developed on the basis of linear-quadratic regulator method and a continuous-optimal control concept. The damping force in the SOBMD system can be manipulated according to the structural response; therefore, the SOBMD system affords the possibility of improving the displacement or acceleration response compared with the original OBMD system. Both of the numerical analysis and the experimental verification demonstrated the superior seismic mitigation ability of the SOBMD system. Several earthquake events with different characteristics were simulated in a series of numerical analysis to further verify the performance of the proposed SOBMD system. In short, the benefits of both the active and passive control system are successfully combined in the proposed SOBMD system.
舞動青春－陽明熱舞社20×21屆
(國立陽明大學, 2018-06)
陽明熱舞社
Enhanced linear reformulation for engineering optimization models with discrete and bounded continuous variables
(2018-06-01)
An, Qi
;
Fang, Shu-Cherng
;
Li, Han -Lin
;
Nie, Tiantian
;
資訊管理與財務金融系註：原資管所+財金所
In this paper, we significantly extend the applicability of state-of-the-art ELDP (equations for linearizing discrete product terms) method by providing a new linearization to handle more complicated non-linear terms involving both of discrete and bounded continuous variables. A general class of "representable programming problems" is formally proposed for a much wider range of engineering applications. Moreover, by exploiting the logarithmic feature embedded in the discrete structure, we present an enhanced linear reformulation model which requires half an order fewer equations than the original ELDP. Computational experiments on various engineering design problems support the superior computational efficiency of the proposed linearization reformulation in solving engineering optimization problems with discrete and bounded continuous variables. (C) 2017 Elsevier Inc. All rights reserved.