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IEEE International Conference on Consumer Electronics-Taiwan (ICCE-TW)

作者： Po-Chun Ting Yu-Cheng Liu Ph.D. Program of Mechanical and Aeronautical Engineering Feng Chia University Taichung City Taiwan Master Program of Electro-Acoustics Feng Chia University Taichung City Taiwan

ISBN: (数字)9798350386844

ISBN: (纸本)9798350386851

The aim of this study is to propose innovative three-dimensional channel-based and scene-based measurement techniques for spatial sound fields, based on two-dimensional measurement and analysis, which can be used for measurement and analysis of important acoustic parameters in concert halls with more than 1,000 seats. The results were compared with actual reverberation time 60 (RT 60 ) and early decay time (EdT) measurements obtained on site in 2006, with differences between the methods proposed in this study and on-site measurements ranging from 0.2 s~0.4 s. Scene-based results were closest, with an average error of only 0.027 s. The error decreased as the frequency increased, reaching a minimum of 0.004 s. In addition, scene-based measurement not only simplifies the complex and tedious measurement processes of the past, but also produces more diverse spatial parameters for a comprehensive understanding of the acoustic characteristics of a space, which designers can quickly grasp and which can be used as references for optimization and improvement.

关键词： Measurement uncertainty Energy measurement Measurement techniques Attenuation measurement Acoustic measurements Extraterrestrial measurements Time measurement

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Influence Analysis of the Acoustic Radiation Characteristics of Circular Hole in Headphone Using Specific Flow Resistance

Influence Analysis of the Acoustic Radiation Characteristics...

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IEEE International Conference on Consumer Electronics-Taiwan (ICCE-TW)

作者： Tzu-Hsuan Lei Shu-Chien Wu Kuang-Che Lo Shu-Chi Liu Yu-Cheng Liu Ph.D. Program of Mechanical and Aeronautical Engineering Feng Chia University Taichung City Taiwan Master Program of Electro-Acoustics Feng Chia University Taichung City Taiwan

ISBN: (数字)9798350386844

ISBN: (纸本)9798350386851

The geometric dimensions of vent holes in headphone products are key to the impedance characteristics of sound wave propagation and, in turn, affect the low-frequency acoustic performance. However, qualitative and quantitative research on this topic is still insufficient. Therefore, we studied headphone rear chamber vent hole, with a diameter and depth of 1.0 mm and 2 mm, respectively. The acoustic specific airflow resistance of the vent hole was measured using a self-made system that consists of a differential pressure meter and a flow controller. Then, the results were input into the model for correction, to complete the verification between finite element simulation and measurements. The results showed that simulations corrected with the specific airflow resistance measurements of vent hole in the headphone chamber not only enhance the accuracy of low-frequency simulations, but also effectively reduce the error, with maximum discrepancy between simulation and measurement decreasing from 1.3% to 0.063%.

关键词： Resistance Headphones Ventilators Atmospheric modeling Vents Acoustic measurements Acoustics

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Study on the Predictions of Acoustic Characteristics of Microspeakers Based on the Specific Airflow Resistance of Ventilation Materials: Mesh Type

SSRN

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SSRN 2024年

作者： Lei, Tzu-Hsuan Liu, Yu-Cheng Ph.D. Program of Mechanical and Aeronautical Engineering Feng Chia University Taichung40724 Taiwan Master Program of Electro-Acoustics Feng Chia University Taichung40724 Taiwan

In this study is presented a method for predicting the acoustic characteristics of microspeakers with mesh-type ventilation materials that combines specific airflow resistance with equivalent circuit model. The specific airflow resistances of eight types of ventilation materials were quantified using a self-made measurement system. These materials were then used to simulate the acoustic properties of 40 φ and 20 φ microspeakers, respectively. The results were compared with simulation results obtained using dr. Maa's porous plate acoustic impedance and actual measurements. After applying a stable correction factor, the self-made measurement system accurately determined specific airflow resistance values with high reproducibility and stability. A regression curve based on scanning electron microscope obtained porosity and measured specific airflow resistance effectively predicted the specific airflow resistance of materials with known porosity. Applying these values to acoustic simulations, the proposed method significantly improved accuracy, outperforming dr. Maa's method by a factor of six, and closely matched actual measurements. This innovative approach is versatile and applicable to various conditions and types of ventilation materials, as well as enhances predictions of their impact on electro-acoustic product performance. © 2024, The Authors. All rights reserved.

关键词： Porosity

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Ethylene Glycol-Manipulated Syntheses of Calcium Carbonate Particles and dNA Capsules toward Efficient ATP-Responsive Cargo Release

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ACS Applied Bio Materials 2023年第8期6卷 3351-3360页

作者： Lin, Yu-Hsuan Singuru, Murali Mohana Rao Marpaung, david Septian Sumanto Liao, Wei-Ching Chuang, Min-Chieh Department of Chemistry Tunghai University Taichung407224 Taiwan International Ph.D. Program in Biomedical and Materials Science Tunghai University Taichung407224 Taiwan Department of Biosystems Engineering Institut Teknologi Sumatera Lampung Selatan35365 Indonesia Institute of Biochemistry and Molecular Biology National Yang Ming Chiao Tung University Taipei112304 Taiwan

Cargo molecule-encapsulated dNA capsules synthesized with a solid sacrificial template have elicited significant interest in the last decade and have been used for active materials in applications ranging from biosensors to drug delivery. However, the correlation between template properties and the subsequent assembly and triggered release behavior of the resultant carriers remain uninvestigated. In this study, ethylene glycol (EG) was added during the CaCO3 precipitation synthesis to yield particles of various sizes and surface properties, and the adenosine triphosphate (ATP)-responsive release characteristics of the fabricated dNA capsules affected by these particle properties were investigated. The geometry, crystallization, and surface morphology of the CaCO3 particles co-precipitated at various EG concentrations were characterized. We discuss the integrity of cross-linking hybridization, fluorescent molecule internalization, degree of leakage, and release efficiency of the resulting dNA capsules and their relevance brought by particle properties. To achieve efficient encapsulation and cargo release, the surface roughness of the CaCO3 particles was explored and was deemed a key determinant of the compactness of the dNA shell after template removal. This effect was particularly strong in CaCO3 particles in connection with high EG concentrations. The dNA capsules fabricated using 83% EG exhibited low leakage, high loading, and moderate release efficiencies as well as a greater apparent association constant with ATP due to their small particle size and the high-integrity dNA shells. © 2023 American Chemical Society.

关键词： Ethylene glycol

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Students Learning Performance and Engagement in a Visual programming Environment

Students Learning Performance and Engagement in a Visual Pro...

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Proceedings of the 6th International Conference on Innovative Technologies and Learning, ICITL 2023

作者： Wen, Fu-Hsiang Wu, Tienhua Hsu, Wei-Chih Ph.D. Program in Engineering Science and Technology College of Engineering National Kaohsiung University of Science and Technology Kaohsiung Taiwan Department of Management Air Force Institute of Technology Kaohsiung Taiwan Department of Computer and Communication Engineering National Kaohsiung University of Science and Technology Kaohsiung Taiwan

ISBN: (纸本)9783031401121

This study employed a quasi-experimental method to explore differences in students’ learning performance and engagement between visual and textual language programming environments. Specifically, this study examined how strongly engagement dimensions affect participants’ learning achievement in a Scratch experimental setting. One hundred and thirty-two undergraduate students participated. The results revealed that participants with Scratch intervention outperformed those with text-based language instructions in terms of performance and behavioral, emotional, cognitive, and agentic engagement. The findings indicated that engagement significantly predicted student academic success in a visual learning environment. This study concluded that visual programming tools such as Scratch help novices engaged and effectively learn core aspects of programming concepts. Additionally, student engagement deepens an understanding of predictions of programmers’ behaviors and achievements and mechanisms behind the effectiveness of visualization intervention. © 2023, The Author(s), under exclusive license to Springer Nature Switzerland AG.

关键词： Students

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Enhancement and Optimization of the Propulsion System Modules of Unmanned Aerial Vehicles

Enhancement and Optimization of the Propulsion System Module...

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2024 Asia Conference on Electronic Technology, ACET 2024

作者： Shiau, Y.R. Fang, J. Huang, Y.C. Department of Industrial Engineering and Systems Management Feng Chia University No. 100 Wenhwa Rd. Seatwen Taichung Taiwan Department of Aerospace and Systems Engineering Feng Chia University No. 100 Wenhwa Rd. Seatwen Taichung Taiwan Ph.D. Program of Mechanical and Aeronautical Engineering Feng Chia University No. 100 Wenhwa Rd. Seatwen Taichung Taiwan

ISBN: (纸本)9781510681361

Unmanned aerial vehicles (UAVs) are widely used in various industries. The present study focused on the optimization of the configuration of the vertical electric ducted fans (EdFs) of UAVs to enhance the vertical takeoff and landing (VTOL) performance of UAVs, improve the configuration of their propulsion system, address the potential risk of exposed propellers, and reduce the space required between the fluid channel and the outlet in horizontal EdFs. A UAV aircraft module with a vertical EdF configuration was designed, following which structural analysis and flow field analysis were conducted using Ansys. The results of these analyses indicate that the overall flow of the designed module is smooth and stable without vortex generation and that the inlet and outlet air velocity performance of this module is excellent. The lift parameters of the rotor groups of the designed module are identical to each other;thus, the flight stability of the UAV in the air can be maintained, and the requirements for optimized design can be met. This study makes two contributions to the literature. First, the structural module of a vertical EdF propulsion system was proposed with an encapsulated impeller set hidden inside the vehicle structure to reduce the risk of propeller exposure. Second, the configuration of vertical EdF compared to the horizontal configuration shortens the airflow channel, which helps to stabilize the wind speed at the outlet, thereby increasing lifting capacity and propulsion efficiency. © 2024 SPIE.

关键词： Propellers

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Intelligent Adjustment of Temperature Control Parameters Based on deep Reinforcement Learning for Stretch Blow Molding Machine 25

Intelligent Adjustment of Temperature Control Parameters Bas...

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25th International Conference on Mechatronics Technology, ICMT 2022

作者： Hsieh, Ping-Cheng Su, Guan-Lin Lin, Yi-Te Lin, Wei-Bo National Changhua University of Education Department of Mechatronics Engineering Changhua Taiwan Feng Chia University Department of Mechanical and Computer-Aided Engineering Taichung Taiwan Feng Chia University Ph.D. Program of Mechanical and Aeronautical Engineering Taichung Taiwan

ISBN: (数字)9781665461955

ISBN: (纸本)9781665461955

Stretch blow molding is the main technology used in the production of PET bottles. The stretch blow molding machine is usually composed of preform infeed system, transfer system, heating system, molding system, bottle discharge system, etc. Among them, the temperature control of the heating system is one of the key factors affecting the quality of PET bottle, especially in the face of the environmental temperature changes greatly between morning and evening in some seasons. The on-site operators of the stretch blow molding machine often need to adjust the infrared heating lamps in the heating system several times. The adjustment process is highly dependent on experience of the personnel. It has become a production challenge for the bottle manufacturers. Therefore, this paper takes the heating system of the stretch blow molding machine as the object and uses the deep reinforcement learning method to develop an intelligent adjustment technique of temperature control parameters. The proposed method can improve the problems such as the interference of environmental temperature changes and the aging variation of infrared heating lamps. The experimental results show that the proposed method can adjust the temperature control parameters automatically in the heating process to eliminate the effect of the environmental temperature change and to control the surface temperature of the preforms stably within ±3 °C of the target temperature (the requirement is within±5 °C). © 2022 IEEE.

关键词： deep learning

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Enhancement of piezophototronic hydrogen evolution reaction through the polarization of ferroelectric Bi4Ti3O12 microplates

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International Journal of Hydrogen Energy 2024年 50卷 15-25页

作者： Chang, Shun Cheng Chen, Po-Han Chen, Yu-Ching Wu, Jyh Ming Department of Materials Science and Engineering National Tsing Hua University 101 Section 2 Kuang Fu Road Hsinchu300 Taiwan High Entropy Materials Center National Tsing Hua University Section 2 Kuang Fu Road 101 Hsinchu300 Taiwan Ph.D. Program in Prospective Functional Materials Industry National Tsing Hua University 101 Section 2 Kuang Fu Road Hsinchu300 Taiwan

In this study, we analyzed the properties of Bi4Ti3O12 microplates in the context of hydrogen evolution reaction. Piezoresponse force microscopy revealed a typical butterfly curve, indicating that as-synthesized Bi4Ti3O12 exhibits ferroelectric properties. Under ultrasonication, the amount of hydrogen produced by polarized (2000 V) Bi4Ti3O12 increased from 728 to 1349 μmol g−1, which was 1.85 times higher than that generated by unpolarized Bi4Ti3O12. The increase in hydrogen evolution rate may be attributed to the gradual alignment of polarization within the ferroelectric domains of Bi4Ti3O12. Moreover, with synergistic piezophototronic activity, the amount of hydrogen produced by Bi4Ti3O12 was further increased to 1478 μmol g−1, which was 200% higher than that generated by unpolarized Bi4Ti3O12. Theoretical calculations revealed that Bi4Ti3O12 microplates exhibit a high piezoelectric potential along the x-axis, which is consistent with the spontaneous polarization of the microplates. By applying an external polarization field, ferroelectric polarization was activated to effectively separate free charges and extend carrier lifetime (from 0.6 to 0.84 ns). The application of an external electric field to ferroelectric Bi4Ti3O12 appears to be a favorable strategy for enhancing its piezophototronic activity. Our findings may facilitate future studies in the fields of environmental science and renewable energy. © 2023 Hydrogen Energy Publications LLC

关键词： Bismuth compounds

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High-Efficiency Microinverter With Interleaved Switching and Asymmetrical Unipolar Modulation

High-Efficiency Microinverter With Interleaved Switching and...

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International Future Energy Electronics Conference (IFEEC)

作者： Che-Yu Lu Ming-Yueh Hsieh Department of Electrical Engineering National United University Miaoli Taiwan Ph.D. Program in Materials and Chemical Engineering National United University Miaoli Taiwan

This paper introduces a high-efficiency two-stage power microinverter. In the dc-dc stage, a three-phase interleaved inverse buck-type converter is adopted to regulate the dc-bus voltage and improve the input ripples. A band-stop filter and a PR controller are employed to eliminate the double-line frequency ripple. Furthermore, a highly reliable inverter combines an H-bridge topology and two low-frequency switches. Interleaved switching and asymmetrical unipolar modulation are used to improve conversion efficiency. The high and low switching frequency legs synchronization minimizes distortion on the output voltage waveform. Finally, all control algorithms are implemented in a TI dSP TMS320F28069 chip. A 2 kW prototype utilizing GaN devices has been developed and verified. The average efficiency of the overall system achieves 98%.

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Separation of Heart and Lung Sounds by A deep Network-Based Model

Separation of Heart and Lung Sounds by A Deep Network-Based ...

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IEEE International Conference on Knowledge Innovation and Invention (ICKII)

作者： Tung-Sheng Tsai Chun-Chieh Hsu Ching-Lung Hsieh Yi-Jui Liu Ph.D. Program of Electrical and Communications Engineering Feng Chia University Feng Chia University Chung Shan Medical University Hospital

Breath and heart sounds are the two main biological sound signals. Heart sounds are produced by the beating of the heart caused by blood flows in the heart valves and blood vessels, while lung sounds are produced by the flow of air in and out of the airways during the breathing cycle. Both signals are recorded from the chest area. However, these two signals are mostly superimposed on each other, so it is of great research interest to separate these heart sound signals (HSS) and lung sound signals (LSS). A "Looking to Listen" model developed by Google, is a joint audiovisual model for isolating a single speech signal from a mix of sounds such as other speakers and background noise. In this study, we evaluated the feasibility of separating HSS and LSS by the audio part of the "Looking to Listen" model. We collected the pure HSS (phSS) and pure LSS (PLSS) data from the public website (kaggle dataset, CoronaHack Respiratory Sound dataset). Then, heart and lung sounds (MHLS) were combined HSS and LSS with different weighting power (3:7, 5:5, and 7:3). A total of 8076 MHLSs were generated with 72% of the data in the training set, 10% in the validation set, and 18% in the test set. The cross-correlation coefficient (CC) of pure sound and mixed sound and CC of separated and pure sounds were compared to evaluate the efficacy of extraction HSS or LSS from MHLS. The results showed the mean CC was 0.4, 0.7, and 0.9 for pure HSS and MHLS with 3:7, 5:5, and 7:3, respectively; and the mean CC was 0.79, 0.87, and 0.97 for pure HSS and predicted HSS with 3:7, 5:5, and 7:3, respectively. The mean CC was 0.9, 0.7, and 0.4 for pure LSS and MHLS with 3:7, 5:5, and 7:3, respectively. The mean CC was 0.95, 0.91, and 0.81 for pure LSS and predicted LSS with 3:7, 5:5, and 7:3, respectively. The feasibility of separating HSS and LSS by the audio part of the "Looking to Listen" model was validated.

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