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2024 IEEE Energy Conversion Congress and Exposition, ECCE 2024

作者： Voyer, Nicolas Nakabayashi, Akinu Kondo, Ryota Mitsubishi Electric Research and Development Centre Europe Rennes France Mitsubishi Electric Corporation Advanced R&d Center Amagasaki Japan

ISBN: (纸本)9798350376067

This paper introduces a method that reaches the closed-form expression of waveforms in linear electronic circuits, enabling fast and accurate simulations. The method is automated for circuits described with Modified Nodal Analysis (MNA) formalism, that is easy to reach with collection of Kirchhoff laws. The method produces same closed-form expressions of waveforms as in State-Space Analysis (SSA), expressed as sums of weighted exponential functions of time, driven by characteristic frequencies of the circuit. However, the proposed method does not use SSA formalism and can therefore be applied to any circuit. The precise formulation of waveforms enables its computation in a single step with ultimate accuracy and constant CPU effort. Significant acceleration ratio was verified on DC/DC circuit by comparison with commercial simulation tool. The proposed method can effectively reduce the calculation effort at the design and verification stages of applications which need loss analysis over long mission profiles, like mobility applications. © 2024 IEEE.

关键词： Exponential functions

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A Novel Evaluation Method of the Effect of Space Charge in Insulating Materials to IGBTs Blocking Voltage 5

A Novel Evaluation Method of the Effect of Space Charge in I...

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5th IEEE International Conference on Dielectrics, ICD 2024

作者： Muto, Hirotaka Yamatake, Atsushi Shiota, Hiroki Kishimoto, Koki Kitamura, Shuichi Mitsubishi Electric Corporation Advanced Tehcnology Research and Development Center Amagasaki Japan Mitsubishi Electric Corporation Power Device Factory Fukuoka Japan

ISBN: (纸本)9798350308976

We propose a novel evaluation method for the effect of space charge in passivation materials to blocking voltage of high voltage power devices like IGBT and diode devices. In the method, an electrode called Guard Probe (GP) is placed above the edge termination area of high voltage power chip. Dependence of the collector current on collector-emitter voltage (Ice-Vce curve) is measured repeatedly with increasing the voltage applied to the GP electrode step-by-step. The GP electrode simulates the space charges which are the major cause of long-term instability of high voltage devices. The GP voltage when an indication of avalanche breakdown, that is a sudden increase of Ice, appeared in Ice-Vce curve just below the rated voltage, is defined as 'the GP voltage at avalanche breakdown'. A good correlation between the GP voltage at avalanche breakdown and long-term instability of Ice was observed for several IGBT and diode devices with different edge termination structures and passivation materials. Therefore, the GP voltage at avalanche breakdown can be used as an index of ruggedness of high voltage power devices against external electric field perturbation by space charges in passivation and encapsulation materials. © 2024 IEEE.

关键词： Ice

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An improved simulation of temperature field in Laser–low current MAG of thin galvanized steel sheets

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International Journal of advanced Manufacturing Technology 2025年第7期138卷 3441-3455页

作者： Xu, Shixiang Sun, Zhenbang Han, Yongquan Sun, Haotian Xing, Yucheng Zhang, Shiquan School of Materials Science and Engineering Inner Mongolia University of Technology Hohhot010051 China Engineering Research Center of Development and Processing Protection of Advanced Light Metals Ministry of Education Hohhot010051 China Inner Mongolia Metal Material Research Institute Baotou014034 China

This study aimed to achieve efficient and precise connection of thin steel sheets for vehicles by analyzing the thermal process of Laser-MAG hybrid high-speed welding lap of thin galvanized steel sheets. A high-speed camera combined with an NI AD data acquisition system were used, and the transition behavior and electrical signals of low-current MAG and Laser-MAG hybrid welding were examined. The thin sheet MAG welding droplet transition method mainly comprised short-circuit transfer. During the short-circuit phase, the voltage decreased and the current increased sharply, forming a short-circuit liquid column. When current increased to a certain level, the liquid bridge burst, the droplets carried heat and kinetic energy to the weld pool, the arc voltage returned to a no-load state, and the arc was re-ignited. In the arcing phase, the current first decreased steeply and then slowly, while the voltage decreased slowly and smoothly. According to the different heat source characteristics of the arc combustion and short-circuit stages during short-circuit transition, a new MAG heat source for low-current short-circuit transition was developed. This study employed a double-ellipse heat source with different powers for the arc combustion stage as well as a uniform body heat source that considered the thermal and kinetic energies of the melt droplets for the short-circuit stage. The thermal input of low current MAG welding was described by double-ellipse and uniform body heat source periodic loading. Moreover, the laser exerted an attraction and compression influence over the arc during the hybrid welding, which promoted the droplet transfer. Therefore, based on the novel MAG heat source, a hybrid Laser-MAG heat source in the short-circuit transition mode was developed. The laser beam heat source was described using a three-dimensional column heat source, the arc attraction and compression by the laser were considered indirectly through distribution parameter tuning for th

关键词： High speed cameras

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Multi-Level Voltage Switching Circuit Design 15

Multi-Level Voltage Switching Circuit Design

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15th International Conference on advanced Scientific Computing, ICASC 2024

作者： Kovacs, Gergo Nelega, Raluca Oprea, Alexandru Surducan, Vasile Surducan, Emanoil Puschita, Emanuel Tech. Univ. of Cluj-Napoca and Ctr. for Advanced Research and Technologies for Alternative Energy @ National Institute for Research and Development of Isotopic and Molecular Technologies Communications Department @ Cluj-Napoca Romania National Institute for Research and Development of Isotopic and Molecular Technologies Center for Advanced Research and Technologies for Alternative Energy @ Cluj-Napoca Romania Technologies for Alternative Energy @ National Institute for Research and Development of Isotopic and Molecular Technologies Cluj-Napoca Romania

ISBN: (纸本)9798350356526

This paper presents the detailed design process of a custom circuit board, comprised of six switching units. Each unit integrates an optocoupler, a PNP transistor, and a resistive voltage divider to achieve the primary objective of switching a six-channel 25 V supplied circuit using control signals. The optocoupler ensures electrical isolation between the low voltage and high voltage areas, enhancing safety and reducing interference. The PNP transistor acts as a switch, controlled by the low voltage signal, while the resistive voltage divider assures the proper polarization of the transistor. The circuit is designed to support multiple single-ended voltage signaling protocols, with voltage levels ranging from 1.8 V to 5 V, making it suitable for various applications that require precise, isolated control of higher voltage loads using low-voltage signals. © 2024 IEEE.

关键词： Integrated circuit manufacture

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Power Cycle Reliability of Cu Sintered Die-Bonding Using of Pressure Contact Structure

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Journal of Japan Institute of Electronics Packaging 2022年第3期25卷 218-224页

作者： Negishi, Motohiro Sugama, Chie Ishikawa, Dai Natori, Michiko Kawana, Yuki Nakako, Hideo Reseach & Innovation Promotion Headquarters Advanced Technology Research & Development Center 7-7 Shinkawasaki Saiwai-ku Kanagawa Kawasaki-shi212-0032 Japan Reseach & Innovation Promotion Headquarters Advanced Technology Research & Development Center 48 Wadai Ibaraki Tsukuba-shi300-4247 Japan

We are conducting the advanced development of a sintering Cu paste (with/without pressure type) for use in power devices. For this report, we carried out a power cycle test and its Weibull analysis using sintering Cu as a bonding material and compared the results to the power cycle lives of Sintering Ag and high-lead solder. The characteristic life for sintering Cu without pressure was about 14 times higher than that of high lead solder when the power cycle condition was T j max = 175°C and ΔT j = 100°C, and about 40 times higher for sintering Cu with pressure. Therefore, the sintering Cu has a superior bonding reliability compared with sintering Ag and high lead solder. Copyright© The Japan Institute of Electronics Packaging.

关键词： Sintering

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A Three-Dimensional SPH Simulation of Lander Footpad Impact on a Lunar Regolith Bed

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Computer Modeling in Engineering & Sciences 2025年第2期142卷 2045-2066页

作者： Wanqing Yuan Huiying Xie Can Huang Xiaoliang Wang Qingquan Liu Department of Mechanics School of Aerospace EngineeringBeijing Institute of TechnologyBeijing100081China Institute of Computational Aerodynamics China Aerodynamics Research and Development CenterMianyang621000China Institute of Large Structures for Advanced Industrial Equipment Beijing Institute of TechnologyZhuhai519088China

Landing spacecraft experience significant impact forces during landing,resulting in large deformation and failure in the soil surface,which severely affects landing safety and *** paper establishes a smoothed particle hydrodynamics(SPH)model based on the theory of soil elastoplastic constitutive relations to describe the process of a lander’s footpad impacting lunar regolith *** model can provide engineering indices such as impact load and penetration depth,and illustrate the large deformation and crater characteristics of the regolith.A detailed analysis of the response of the footpad and lunar regolith during landing reveals that the process can be broadly divided into two stages of rapid penetration and oscillatory ***,there are significant similarities in the landing process under different landing velocities and footpad *** research investigates the large deformation and crater characteristics of the lunar regolith *** results demonstrate two failure modes in the *** the impact of a footpad with a smaller mass,the final failure surface of the regolith exhibits a bowl-shaped profile with a uniformly open *** contrast,under the impact of a footpad with a larger mass,the final failure surface of the regolith presents an urn-shaped profile with a large abdomen and a small ***,the impact craters in both scenarios show a bowl-like *** cases of high-velocity impacts,the impact crater exhibits obvious blocky spalling on its *** SPH model developed in this study can be applied to predict the large deformation and failure response of lunar soil under the impact of rigid structures as well as the impact load and penetration *** effectively predicts the dynamic response of the landing process,which is expected to provide a reference for engineering design.

关键词： SPH footpad load lunar regolith impact crater

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Hollow tubular-structured molybdenum diselenide/carbon hybrid decorated by titanium dioxide nanoparticles for superior lithium-ion storage

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稀有金属（英文版） 2025年第2期44卷 879-888页

作者： Ren-Quan Hu Yi-Fan Qin Jing-Xuan Li Peng Zhang Ning Zhao Teng Wang Ya-Qi Xu Qing-Yang Mu Yong Yang Research and Development Institute of Northwestern Polytechnical University in Shenzhen Shenzhen 518057China State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi'an 710072China National Key Laboratory of Special Vehicle Design and Manufacturing Integration Technology Baotou 014000China

One-dimensional nanomaterials with hollow structures could provide large space for ion storage and charge ***,TiO2/MoSe2-Carbon nan-otube composite(NT)materials were designed and fabri-cated by the template method and the chelation coordination *** stability and conductivity were improved by the presence of titanium and hollow tubular-architecture carbon in the whole *** a result,the as-prepared TiO2/MoSe2-Carbon hybrid achieved a high-rate performance of 760.0 mAh·g-1 at a current density of 0.1 A·g-1,while still obtaining stability after 300 charge/discharge *** enhancement of the lithium storage capacity mainly contributed to the acceleration of the electron conductivity and the storage ***,the hollow structure reduced the volume strain and stress caused by the rapid insertion and removal of lithium ions,which ensured the favorable stability of lithium *** experiment shows that the kinetic of the TiO2/MoSe2-carbon hybrid during the lithium storage process is domi-nated by the pseudocapacitance *** work provides a new idea and scheme for the design and preparation of hierarchical nanotube composite electrode materials.

关键词： Hollow structure Hierarchical structure Carbon nanotubes MoSe2 nanosheets Lithium-ion batteries

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Radio Frequency-Based Drone Detection and Classification using Deep Learning Algorithms 31

Radio Frequency-Based Drone Detection and Classification usi...

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31st International Conference on Software, Telecommunications and Computer Networks, SoftCOM 2023

作者： Nelega, Raluca Turcu, Romulus Valeriu Flaviu Belean, Bogdan Puschita, Emanuel Tech. Univ. of Cluj-Napoca and Center for Advanced Research and Technologies for Alternative Energy National Institute for Research and Development of Isotopic and Molecular Technologies Communications Department Cluj-Napoca Romania Babes-Bolyai University and Center for Advanced Research and Technologies for Alternative Energy National Institute for Research and Development of Isotopic and Molecular Technologies Biomolecular Physics Cluj-Napoca Romania National Institute for Research and Development of Isotopic and Molecular Technologies Center for Advanced Research and Technologies for Alternative Energy Cluj-Napoca Romania

ISBN: (纸本)9798350301076

The widespread availability of drones has determined the need for identification systems to prevent their use in illicit activities. This paper focuses on a radio-frequency (RF) detection and classification method based on the You Only Look Once (YOLO) object detection algorithm. Considering the signal spectrograms as input images, the YOLO algorithm is used for spectro-temporal localization and classification of RF signals emitted by 7 different drone types, each operating in video streaming mode. The classification algorithm involves extensive labeling and training procedures, performed using the RF signals registered from all aforementioned drone types, available within the DroneDetect dataset. Furthermore, the impact of the annotation strategy on the model performance is analyzed by comparing two different strategies, namely (1) annotation of the RF transmission bursts as multiple objects and (2) annotation of the RF transmission bursts in a sequence as a single object. The result analysis demonstrates that the information about the time distribution of video transmission bursts provided by the second annotation strategy (i.e., annotation of the RF transmission bursts in a sequence as a single object) improves the performance of the model in terms of precision, recall, and mean average precision considering an intersection over union (IoU) threshold of 50%, and a IoU threshold range of [0.5:0.95], respectively. © 2023 University of Split, FESB.

关键词： Classification (of information)

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Solid-conversion synthesis of three-dimensionally ordered mesoporous ZSM-5 catalysts for the methanol-to-propylene reaction

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Frontiers of Chemical Science and Engineering 2024年第8期18卷 111-122页

作者： Weilong Chun Chenbiao Yang Xu Wang Xin Yang Huiyong Chen School of Chemical Engineering Northwest UniversityXi’an 710069China International Science&Technology Cooperation Base for Clean Utilization of Hydrocarbon Resources Chemical Engineering Research Center of the Ministry of Education for Advanced Use Technology of Shanbei EnergyCollaborative Innovation Center for Development of Energy and Chemical Industry in Northern ShaanxiNorthwest UniversityXi’an 710069China

A facile synthesis of hierarchical ZSM-5 with the three-dimensionally ordered mesoporosity(3DOm ZSM-5)was achieved by solid conversion(SC)of SiO_(2)colloidal crystals to high-crystalline *** products of 3DZ5_S/C and 3DZ5_S,which were severally transformed from the carbon-padded SiO_(2)colloidal crystals and the initial SiO_(2)colloidal crystals,exhibited not only a similar ordered structure and acidity but also higher crystallinity and more balanced meso-/micropore combination in comparison with 3DZ5_C obtained by the conventional confined space crystallization *** three synthesized 3DZ5 catalysts showed improved methanol-to-propylene performance than the commercially microporous ZSM-5(CZ5),embodied in five times longer lifetime,higher propylene selectivity and S_(propylene)/S_(ethylene) ratio(P/E),and superior coke toleration with lower formation rate of coke(R_(coke)).Moreover,the 3DZ5_S catalyst in situ converted from SiO_(2)colloidal crystals presented the highest selectivities of propylene(42.51%)and light olefins(74.6%)among all three 3DZ5 *** high efficiency in synthesis and in situ utilization of SiO_(2)colloidal crystals demonstrate the proposed SC strategy to be more efficiently and eco-friendly for the high-yield production of not only 3DOm ZSM-5 but also other types of hierarchical zeolites.

关键词： hierarchical zeolite three-dimensionally ordered mesoporosity ZSM-5 solid conversion methanol-to-propylene

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Continuous and Non-Contact Extraction of Respiratory Signal and Rate from Thermal Video 10

Continuous and Non-Contact Extraction of Respiratory Signal ...

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10th International Conference on Signal Processing and Intelligent Systems, ICSPIS 2024

作者： Saidi, Maryam Rezaei, Mohammad Beigzadeh, Maryam Mohammadian, Amin Lari, Abdolaziz Azizi Shahrood University of Technology Electrical Engineering Faculty Bioelectric Department Shahrood Iran Biosignals processing Group Research Center for Development of Advanced Technologies Tehran Iran

ISBN: (纸本)9798331532543

Achieving a simple, non-contact, non-invasive, and non-disruptive method for measuring and monitoring vital signs, including respiratory signals, is crucial in this field of research. This paper aims to implement algorithms for extracting respiratory signals and breathing rates from thermal facial images. Unlike many previous studies, where the algorithm was validated under resting conditions, this paper designs a protocol to capture a diverse range of respiratory activity datasets in varying conditions. Data were collected from six healthy individuals, with thoracic and abdominal contact-based respiratory signals used as reference signals. Processing steps, including robust facial tracking in thermal images and precise selection of target areas around the nose is implemented to extract respiratory signal and rates from the thermal video. The effectiveness of the proposed computational method is assessed through both quantitative and qualitative metrics, considering a variety of breathing patterns beyond just resting conditions. © 2024 IEEE.

关键词： Thermography (imaging)

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