Showing papers in "Sensors and Materials in 2021"
Journal Article•
TL;DR: Tang et al. as discussed by the authors investigated the damping effects due to different geometries and compared to theory, and showed that if edge and finite-size effects are included in the model, reasonably accurate predictions of the quality factors can be obtained even for small geometry and comb drives, and derived an empirical formula that predicts the quality factor for a range of plate sizes and comb designs.
Abstract: Author(s): Tang, William; Zhang, Xia | Abstract: A systematic experimental study of viscous air damping in laterally moving planar microstructures is reported. Previous studies indicated that Couette and Stokes flow models underestimate microstructural damping. To investigate this discrepancy, a series of lateral resonant microstructures with different damping plates and combs was fabricated by polysilicon surface micromachining. The resonant frequencies and quality factors of the structures were measured electrically. By analyzing these data, the damping effects due to different geometries were elucidated and compared to theory. The results indicated that if edge and finite-size effects are included in the model, reasonably accurate predictions of the quality factors can be obtained even for small geometries and comb drives. An empirical formula that predicts the quality factor for a range of plate sizes and comb designs was derived. The damping effects as functions of structural thickness and structure-to-substrate separation are also reported.
120 citations
17 citations
TL;DR: Nd:SrY2O4 single crystals were successfully synthesized by the floating zone method, and their photoluminescence (PL) and scintillation properties were investigated as mentioned in this paper.
Abstract: Nd:SrY2O4 single crystals were successfully synthesized by the floating zone method, and their photoluminescence (PL) and scintillation properties were investigated. The X-ray diffraction patterns of synthesized Nd:SrY2O4 demonstrate no impurity phase. Under X-ray irradiation, the samples show scintillation with sharp emission lines at around 900, 1064, and 1300 nm due to the 4f–4f transitions of Nd3+. The PL and scintillation decay time constants were approximately 170–180 and 200–270 μs, respectively. The scintillation intensity was proportional to the X-ray dose exposure in the dynamic range from 0.06 to 60 Gy/h.
15 citations
14 citations
13 citations
TL;DR: In this study, educational social learning theory and a statistical multiple-criteria decisionmaking (MCDM) methodology are creatively cross-employed to comprehensively cross-evaluate online courses and sensor technologies.
Abstract: In this study, educational social learning theory and a statistical multiple-criteria decisionmaking (MCDM) methodology are creatively cross-employed to comprehensively cross-evaluate online courses and sensor technologies. This was accomplished by means of an in-depth survey of large-scale current online-course users and professional experts with the highest research reliability, validity, accuracy, and representativeness. The three most valuable and contributive conclusions of this study are as follows: (1) The repurposing technology function (RTF) of online-course technology can combine software sensor (SS), motion sensor (MS), and environment sensor (ES) technologies to not only detect moving objects but also achieve cognition in the environment (e.g., by using a face sensor) to extract emotions of course participants in response to words and phrases during lectures to increase online-course learning performance. (2) The course professionalization technology function (CPTF) of online-course technology can merge SS, MS, and ES technologies to control online-course hardware sensor devices and equipment to control the depth and span of online-course content to strengthen online-course learning performance. (3) The course evaluation technology function (CETF) of online-course technology can consolidate SS, MS, and ES technologies to not only empirically evaluate online-course implementation but also indirectly appraise online-course learning performance. © 2021 M Y U Scientific Publishing Division. All rights reserved.
12 citations
12 citations
TL;DR: In this paper, the authors present a survey of the state-of-the-art architecture and urban planning departments at Chung Hua University in Taiwan, including the departments of Landscape Architecture and Architecture and Urban Planning.
Abstract: 1School of Urban and Environmental Science, Huaiyin Normal University, No. 111, ChangJang West Road, Huai’an City, Jiangsu Province 223300, China 2Department of Civil Engineering, Chung Hua University, No. 707, WuFu Road, Section 2, Hsinchu 30012, Taiwan 3College of Engineering, Chung Hua University, No. 707, WuFu Road, Section 2, Hsinchu 30012, Taiwan 4Department of Landscape Architecture, Chung Hua University, No. 707, WuFu Road, Section 2, Hsinchu 30012, Taiwan 5Department of Architecture and Urban Planning, Chung Hua University, No. 707, WuFu Road, Section 2, Hsinchu 30012, Taiwan 6Computer Engineering Department, Adamson University, 900 San Marcelino Ermita, Manila, Philippines
11 citations
TL;DR: In this article, the authors have studied the scintillation properties of non-doped and Prdoped BaO-B2O3-SiO2 glasses and glass-ceramics and confirmed that the X-ray diffraction peaks can be ascribed to the BaSiO3 crystalline phase in the glassceramic samples.
Abstract: We have studied the scintillation properties of non-doped and Pr-doped BaO–B2O3–SiO2 glasses and glass-ceramics. The glass transition temperature (Tg), the temperature of crystallization onset (Tx), and the crystallization peak (Tp) were determined by differential thermal analysis. The glass-ceramics were obtained by heating at three different temperatures (Tg + 50 °C, Tx, and Tp). We confirmed that the X-ray diffraction peaks can be ascribed to the BaSiO3 crystalline phase in the glass-ceramic samples. In the X-ray-induced scintillation spectra, we observed the intrinsic luminescence of the host glass and luminescence due to the 4f–4f transition of Pr3+ ions. In addition, the 1% Pr-doped BaO–B2O3–SiO2 glass-ceramic with heating at Tg + 50 °C clearly showed luminescence in the wavelength range from 250 to 350 nm under X-ray excitation. Its photoluminescence (PL) decay time was estimated to be 26.28 ns and its luminescence is considered to be due to the 5f–4f transition of Pr3+ ions.
8 citations
7 citations
TL;DR: A system for localized obstacle avoidance with a haptic-based interface for VIBs implemented using a robotic operating system (ROS) to improve the obstacle detection of existing assistive devices.
Abstract: Focus on the development of assistive devices for visually impaired and blind people (VIBs) to provide assistance in their safety and mobility has increased, but making such devices portable is still a challenge. We propose a system for localized obstacle avoidance with a haptic-based interface for VIBs implemented using a robotic operating system (ROS) to improve the obstacle detection of existing assistive devices. With a depth camera sensor, an obstacle localization algorithm was developed utilizing the ROS framework to identify key regions to detect head-level, left/right torso-level, and left/right ground-level obstacles. The proposed wearable device provides a discernible array of haptic feedback to convey the perceived locations of obstacles. The system was tested by blindfolded volunteers to determine the accuracy in determining object locations in various environments. Experimental results showed the consistency of the system across different setups. The obstacle detection algorithm was optimized and evaluated to discriminate noises and concurrently detect smaller obstacles, thus making detection more robust. Subsequently, the Eulerian video magnification method was used to determine the level of vibration isolation for a prototype.
TL;DR: The history of SPM, surface force and singlemolecule force measurements, which unveiled molecular processes at biointerfaces, and representative works in nano-bioscience are introduced.
Abstract: Scanning probe microscopy (SPM) is a powerful method for visualizing the structure of materials at the nanoscale. In particular, atomic force microscopy (AFM) has become one of the most used analytical tools in various fields such as physics, chemistry, and biology. Here, we introduce representative works in nano-bioscience. First, we look back on the history of SPM and introduce the application of AFM in this field. Next, we review surface force and singlemolecule force measurements, which unveiled molecular processes at biointerfaces. Surface force measurements revealed the mechanism underlying the macroscopically observed protein and cell resistance of artificial monolayers and biomolecules. Meanwhile, single-molecule force spectroscopy has enabled researchers to explore the complex interaction of biomolecules from a microscopic viewpoint. These findings will contribute not only to the fundamental understanding of biomolecular processes but also to the design of new nano-biodevices.
TL;DR: In this article, three different fuels, methane, methanol, and hydrogen, were tested to investigate their effects on the operation of a rotary engine by measuring the output power, torque, and exhaust air temperature.
Abstract: Three different fuels, methane, methanol, and hydrogen, were tested to investigate their effects on the operation of a rotary engine by measuring the output power, torque, and exhaust air temperature. The results showed that the output power with methanol was lower than those with methane and hydrogen at the same engine speed. Methanol enabled the engine to have the widest operation range from 5000 to 18000 revolutions per minute (RPM). The engine using hydrogen and methane operated stably in the ranges of 6000 to 10000 RPM and 7000 to 14000 RPM, respectively. Methanol had greater efficiency than hydrogen and methane, and hydrogen had higher output power and torque than methane and methanol. To use methanol for a rotary engine, a higher-pressure pump is required, and a mixture of liquid and gas fuels enables better operation than the use of methane or hydrogen.
TL;DR: In this paper, the scintillation properties of organic-inorganic layered perovskite-type compounds were analyzed using pulsed beams having different linear energy transfers (LETs), initially the decay was slower and then became faster at higher LETs.
Abstract: The scintillation properties of organic–inorganic layered perovskite-type compounds were analyzed using pulsed beams having different linear energy transfers (LETs). Initially the decay was slower and then became faster at higher LETs. A possible cause of the slower decay at higher LETs is the competition between the radiative process and trapping at nonradiative sites, resulting in some excitons not being trapped at nonradiative sites at which other excitons have already been trapped at higher LETs. The faster decay at higher LETs is attributed to the interaction of excited states, such as biexciton formation or a nonradiative Auger process. In addition, the LET dependence was most pronounced for (C6H5C2H4NH3)2PbBr4, whose radiative rate and luminescence quantum efficiency were the highest among the investigated compounds. This result is because the radiative process in this compound, as a major decay process, is more significantly influenced by excited state interactions at higher LETs.
TL;DR: In this paper, the authors demonstrate the rapid synthesis of Ce3+-doped Lu3Al5O12 (Ce3+:LuAG) thick film phosphor grown by laser-assisted chemical vapor deposition.
Abstract: We demonstrate the rapid synthesis of Ce3+-doped Lu3Al5O12 (Ce3+:LuAG) thick film phosphor grown by laser-assisted chemical vapor deposition. The radioluminescence properties of the film are compared with those of Ce3+:LuAG single crystals. The (100) Ce3+-LuAG thick film was epitaxially grown on a (100) Y3Al5O12 substrate at a deposition rate of 16 nm s−1. Under UV and X-ray irradiation, the film emitted a yellow-green light originating from 5d–4f transitions of Ce3+ ions. Under α-ray excitation from an 241Am source, the scintillation decay curve of the Ce3+:LuAG thick film was fitted to two time constants, 32 and 666 ns, associated with the Ce3+ centers and antisite defects in garnet structures, respectively.
TL;DR: In this paper, a quartz crystal microbalance (QCM) was used to fabricate an acetone sensor, and graphene quantum dots (GQDs) were used as a gas-sensing material to modify the QCM.
Abstract: Acetone is a slightly toxic volatile organic gas, which exists in the breath and is closely related to diseases such as diabetes. In this paper, a quartz crystal microbalance (QCM) was used to fabricate an acetone sensor, and graphene quantum dots (GQDs) were used as a gas-sensing material to modify the QCM. GQDs were prepared by citrate pyrolysis and characterized by high-resolution transmission electron microscopy (TEM). The gas sensitivity of the sensor to low concentrations of acetone was investigated. It exhibited good linearity at acetone concentrations of less than 240 ppm with a sensitivity of 16.78 Hz/ppm and a minimum detection limit of 2.5 ppm, and the fitted line had a coefficient of determination R2 of 0.95658. In a mixture of acetone, butanol, and isopropanol, the sensor exhibited good selectivity for acetone. For different acetone concentrations, the response speed of the same sensor was basically the same, and the response and recovery times were 32 and 48 s, respectively. We showed that the prepared gas sensor has good sensitivity, repeatability, and selectivity for low concentrations of acetone.
TL;DR: An improved cubature Kalman filter SLAM (ICKF-SLAM) algorithm based on the cubatures of CKF and ICKF is proposed, which reduces the computational complexity and improves the accuracy of the algorithm.
Abstract: Toward solving some of the problems of low precision, poor stability, and complex calculation in the simultaneous localization and mapping (SLAM) of mobile robots, an improved cubature Kalman filter SLAM (ICKF-SLAM) algorithm based on the cubature Kalman filter SLAM (CKF-SLAM) algorithm is proposed. Firstly, the error covariance matrix of the state vector is obtained through the motion model and observation model of the mobile robot. Then, the information matrix is obtained by the inverse operation, and the information state vector is updated in the prediction and update phases. The proposed method reduces the computational complexity and improves the accuracy of the algorithm. Simulation results show that compared with CKF-SLAM, the root mean square error of ICKF-SLAM is reduced by 11.8%.
TL;DR: A system of distributed energy that combines a dynamic game model (DGM) with the Central Weather Bureau’s weather data, and applies it to the power dispatch of a distributed grid, was found that the managed dispatch of all the power supplies and loads had optimal efficiencies, and the power company's reserve capacity was increased to achieve optimal power dispatch.
Abstract: We propose a system of distributed energy that combines a dynamic game model (DGM) with the Central Weather Bureau’s weather data, and apply it to the power dispatch of a distributed grid. A programmable logic controller (PLC) and human–machine interface (HMI) are used to build the distributed grid for dispatching renewable energy. Moreover, the weather overview for 3 days is downloaded by using MATLAB/Simulink and the Python programming language to link to the weather forecast data, and the power generation on the next day is estimated on the basis of the weather data to dispatch the distributed energy according to the time-of-use power price and management plan announced by the power company. In addition, the weather data may change owing to the changeability of the weather. Therefore, this system can, at any time, obtain the latest weather data, apply the DGM, and dispatch the stored distributed energy in accordance with the power company’s demand bidding measures, so that the power system can achieve the most economic power when there is high demand. It was found that the managed dispatch of all the power supplies and loads had optimal efficiencies, and the power company’s reserve capacity was increased to achieve optimal power dispatch.
TL;DR: In this paper, a fashion business and merchandising course at the University of Fujian in China is described. But the curriculum is different from the one presented in this paper.
Abstract: 1College of Computer Science and Technology, Huaqiao University, Fujian 361021, China 2Department of Fashion Business and Merchandising, Ling Tung University, Taichung 40852, Taiwan 3Department of Aeronautical Engineering, Chaoyang University of Technology, Taichung 413310, Taiwan 4School of Information Engineering, Jimei University, Fujian 361021, China 5School of Humanities and Social Sciences, Harbin Institute of Technology, Shenzhen 518055, China
TL;DR: This paper aims to provide a history of computer science and information engineering at the National Chin-Yi University of Technology in Taichung with a focus on the development of artificial intelligence.
Abstract: 1Department of Computer Science & Information Engineering, National Chin-Yi University of Technology, No.57, Sec.2, Zhongshan Rd., Taiping Dist., Taichung 411, Taiwan 2College of Intelligence, National Taichung University of Science and Technology, No.129, Sec.3, Sanmin Rd, North Dist., Taichung 404, Taiwan 3Department of International Business, National Taichung University of Science and Technology, No.129, Sec.3, Sanmin Rd, North Dist., Taichung 404, Taiwan
TL;DR: The results show that the proposed fuzzy control can greatly improve the fuel economy and reduce the emission of HEVs.
Abstract: We propose a novel fuzzy control strategy for hybrid electric vehicles (HEVs) based on the feature selection genetic algorithm of multivariate data, which greatly shortens the selection time of the optimal parameters of the traditional genetic algorithm. Firstly, we take the fuel consumption and emission of an HEV as the optimization index, and develop a novel fuzzy control method considering parameters of the fuzzy controller with high correlation with the objective function, in which the membership function parameter is optimized by the feature selection genetic algorithm. Finally, the performances of the fuzzy control strategy for an HEV and the novel fuzzy control strategy optimized by the feature selection genetic algorithm under the New European Driving Cycle (NEDC) and Urban Dynamometer Driving Schedule (UDDS) cycle conditions are analyzed and compared. The results show that the proposed fuzzy control can greatly improve the fuel economy and reduce the emission of HEVs.