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2023 IEEE Pulsed Power Conference, PPC 2023

作者： Van Oorschot, Jeroen J. Huiskamp, Tom Eindhoven University of Technology Electrical Energy Systems Group Department of Electrical Engineering Eindhoven5600 MB Netherlands

ISBN: (纸本)9798350332339

Recently we developed the concept and multiple implementations of the Solid-State Impedance-Matched Marx generator (IMG). The generator combines the high-repetition rate and controllability of a solid-state (SiC MOSFET switched) Marx with the fast rise-time possibilities of the impedance-matched topology as proposed by Sandia in 2017. Proper impedance matching should maintain the rise time of the individual Marx stages at the output, regardless of the physical size of the generator. Simulations support this, and practical implementations give good results, but so far, our generators where physically smaller than the propagation time of the pulse front through the generator. When the generators become larger in comparison to pulse rise-time, improperly matched systems will show deteriorated pulse shapes, which we did not show yet. This contribution shows the effect of impedance-matching on both the generator and the load: how the physical size influences the pulse rise-time. More specifically, we take three stages of the IMG, and we connect them either with 15 mm in between, or couple them with a 600-mm coaxial transmission line, with matched and intentionally mismatched versions. This allows us to measure voltages in between the stages and increases the propagation time, which allows us to evaluate reflections on each stage. These results show that proper impedance matching makes the rise-time independent of the physical size of the generator and will lead the way for future IMGs designs. © 2023 IEEE.

关键词： Silicon carbide

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In-Orbit Performance of LoRa for Internet of Things Communication on MicroOrbiter-1 Satellite 13

In-Orbit Performance of LoRa for Internet of Things Communic...

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13th IEEE International Conference on Communication, Networks and Satellite, COMNETSAT 2024

作者： Khamsah, Nova Maras Nurul Moumni, Fahd Nobayashi, Daiki Ikenaga, Takeshi Cho, Mengu Kyushu Institute of Technology Department of Engineering Fukuoka Japan MicroOrbiter Inc Tokyo Japan Kyushu Institute of Technology Department of Electrical and Electronic Engineering Fukuoka Japan Kyushu Institute of Technology Department of Space Systems Engineering Fukuoka Japan

ISBN: (纸本)9798350368086

The integration of Internet of Things (IoT) technology with satellite communications has reformed global connectivity, especially in remote regions that lack terrestrial infrastructure. Recent advancements in optimizing LoRa parameters for satellite-based IoT communications have boosted research in this field. Building on this foundation, the MicroOrbiter-1 satellite developed by MicroOrbiter Inc. in collaboration with the Kyushu Institute of Technology (Kyutech) enhances LoRa-based IoT capabilities in a 1U CubeSat platform. This paper presents the in-orbit performance evaluation of the MicroOrbiter-1 satellite's LoRa-based communication system on the 920 MHz frequency band with three Ground Sensor Terminals (GST) located in Kyutech (Japan), Rancabungur (Indonesia) and Vermont (USA). Key performance metrics such as Received Signal Strength Indicator (RSSI), Spreading Factor, and transmission errors, were analyzed across these locations. The results demonstrated the range of -112 dBm to -127 dBm signal strength for successful communication at low spreading factors. Temporal analysis was conducted using the System Tool Kit to categorize the data received from each terminal. While facing the challenges of power limitation and the lack of an attitude control determination system, the findings in the in-orbit performance analysis of the MicroOrbiter-1 satellite provide valuable insights for optimizing LoRa communication for future satellite missions, especially for CubeSats. © 2024 IEEE.

关键词： Orbits

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Evaluation of Ni–B alloy electroplated with different anionic groups

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Journal of Materials Research and Technology 2023年 27卷 8360-8371页

作者： Cheng, An-Yu Pu, Nen-Wen Liu, Yih-Ming Hsieh, Min-Syuan Ger, Ming-Der Department of Chemistry & Materials Engineering Chung Cheng Institute of Technology National Defense University Taiwan Taoyuan Taiwan Department of Electrical Engineering Yuan Ze University Zhongli Taiwan Taoyuan320 Taiwan System Engineering and Technology Program National Chiao Tung University Hsinchu Taiwan

In order to study the effects of the main nickel salt on the electroplated nanocrystalline Ni–B alloy coating, the deposition rates, surface morphology, crystallinity, grain sizes, hardness, and corrosion resistance of the Ni–B films electrodeposited with plating baths containing separately nickel sulfate (NS) and nickel sulfamate (NSA) under various temperatures and current densities were compared. Under all conditions, the NSA bath system offered higher deposition rates and lower B contents than the NS counterpart because of the formation of Ni-ammonium complex, which can be adsorbed faster than nickel ions. These two groups of coatings had similar surface morphology and crystallinity under all plating conditions except for those plated with the NS bath system at 60 °C, wherein significant changes in surface texture and preferred crystal orientation as well as an abrupt increase in grain size occurred. The coating hardness was optimized by reducing the grain size and increasing the boron content because of the combined effects of grain refinement strengthening and solid solution strengthening. The differences between the two main salt systems can be explained by the presence of ammonium ions in the NSA bath, which not only increased the deposition rate but also maintained the preferred orientation in Ni (111) at high temperature. Our results indicate that, under high current density and high temperature operation conditions, the NSA main salt plating system is a more favorable option for obtaining higher quality Ni–B alloy coatings. © 2023 The Authors

关键词： Sulfur compounds

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A Novel Hybrid CNN-XGBoost Model for Photovoltaic System Power Forecasting 6

A Novel Hybrid CNN-XGBoost Model for Photovoltaic System Pow...

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6th International Youth Conference on Radio Electronics, electrical and Power engineering, REEPE 2024

作者： Bashir, Safia Babikir Farag, Mena Maurice Hamid, Abdul Kadir Adam, Ali Ahmed Abo-Khalil, Ahmed Galal Bansal, Ramesh Sustainable Energy and Power Systems Research Center Research Institute of Sciences and Engineering University of Sharjah Smart Grid and Power Systems Research Group Department of Electrical Engineering Sharjah United Arab Emirates

ISBN: (纸本)9798350382891

Photovoltaic (PV) systems have been at the forefront of renewable energy resources, being a primary alternate source of energy within the electricity supply. However, PV systems are vulnerable to abrupt changes in weather conditions, which affects the stability of DC output generation. Therefore, forecasting the DC power with respect to variable weather conditions is a necessity. This paper proposes a hybrid forecasting model composing of convolution neural network (CNN) and XGBoost models, to enhance the forecasting accuracy during dynamic weather conditions. The model is validated based on a 2.88 kW grid-connected PV system located in Sharjah, UAE. The proposed model has shown superior performance with respect to contemporary models, depicting an RMSE of 44.18 and a R2 of 0.9962, which provides accurate forecasting of DC power under dynamic weather conditions. The infusion of CNN model has significantly enhanced the forecasting accuracy, as compared to the standalone XGBoost. © 2024 IEEE.

关键词： Solar energy

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GENERALIZED BAYES SURE FOR MULTIVARIATE NORMAL DISTRIBUTION UNDER BALANCED-QUADRATIC LOSS

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Journal of Mathematical Sciences (United States) 2024年第2期280卷 262-274页

作者： Karamikabir, Hamid Afshari, Mahmoud Karamikabir, Nasrin Kiaei, Seyed Faridoddin Department of Statistics Faculty of Intelligent Systems Engineering and Data Science Persian Gulf University Bushehr Iran Department of Mathematics Hamedan Branch Islamic Azad University Hamedan Iran School of Electrical and Computer Engineering College of Engineering University of Tehran Tehran Iran

One of the most important subjects in statistics is the theory of estimation. In this paper, we consider the generalized Bayes shrinkage estimator of the mean vector for multivariate normal distribution with the unknown covariance matrix under balanced quadratic loss. Also, we find the minimax and admissible estimator of the mean vector based on the generalized Bayes estimator. We obtain Stein’s unbiased risk estimator (SURE) threshold with a generalized Bayes shrinkage estimator and we find the wavelet shrinkage generalized Bayes SURE. Finally, we present a simulation study to test the validity of the generalized Bayes SURE and the concrete compressive strength dataset is given to test the efficiency of this estimator in denoising. © 2024, The Author(s), under exclusive licence to Springer Nature Switzerland AG.

关键词： Balanced-quadratic loss Generalized bayes estimator Shrinkage estimaton Shrinkage wavelet SURE threshold

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Employing Feature engineering for River Stage Forecasting to Improve Hybrid Model Performance 32

Employing Feature Engineering for River Stage Forecasting to...

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32nd International Conference on Software, Telecommunications and Computer Networks, SoftCOM 2024

作者： Mihel, Anna Maria Pecnik, Spela Vrbancic, Grega Lerga, Jonatan Krvavica, Nino University of Rijeka Faculty of Engineering Department of Computer Engineering Rijeka Croatia University of Maribor Intelligent Systems Laboratory Faculty of Electrical Engineering and Computer Science Maribor Slovenia University of Rijeka Faculty of Civil Engineering Department of Hydrotechnics and Geotechnics Rijeka Croatia

ISBN: (纸本)9789532901382

Establishing early warning systems and efficient management of water resources in tidal reaches is crucial for achieving adequate flood protection. In tidal reaches, the river stage interacts non-linearly with tides (downstream) and discharge (upstream), making the modeling of river processes extremely complex. Data-driven methods have proven helpful for predicting the river stage parameter. This contrasts with existing numerical approaches, which suffer from several limitations. The aim of this study was to predict the river stage of the upstream part of the tidal river, where the influence of salinity is present during the summer months. Using the CNN-LSTM model trained on historical records of the discharge (station of the variable to be predicted), the river stage of three downstream stations, and the point of interest, the prediction was carried out up to 24 hours in advance. By incorporating feature engineering, we achieved an improvement in model results for the longest horizon, confirmed by standard performance metrics, and considered it efficient and effective for risk mitigation. Introducing feature engineering into the data preprocessing resulted in a predictive performance improvement of 0.98% for the Nash-Sutcliffe Efficiency (NSE) metric, 7.0% for the root mean squared error (RMSE) metric, and 7.25% for the mean absolute error (MAE) metric over the second and third-best scenarios using a spectrogram and time-series data. © 2024 University of Split, FESB.

关键词： Mean square error

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Analysis of Rain Visibility Attenuation on Free Space Optics (FSO) for South African Weather Conditions 4

Analysis of Rain Visibility Attenuation on Free Space Optics...

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4th IEEE International Conference on electrical, Computer, and Energy Technologies, ICECET 2024

作者： Mahlobogwane, Zanele Mukubwa, Emmanuel Pillay, Nelendran Tshwane University of Technology Department of Computer Systems Engineering Pretoria South Africa Moi University KipKenya Department of Electrical and Communications Engineering Cheptiret Kenya Durban University of Technology Department of Electronics and Computer Engineering Durban South Africa

ISBN: (纸本)9798350395914

The Free Space Optics (FSO) is a high-speed connectivity system that has the same advantages of speed and bandwidth as that of optic fiber. In comparison to optic fiber, FSO is the preferred choice when it comes to cost and deployment period. However, one of the main challenges with FSO is the changing weather conditions that affect the signal since the transmitted signal is radiated through the atmosphere. This investigation focuses on examining the variables that influence the reduction of visibility at different wavelengths: 750nm, 780nm, 850nm, and 1550nm. The locations of interest concerning visibility and rain data are Pretoria, Upington, Bloemfontein, and Cape Town in the Republic of South Africa. Results indicate that fog attenuates the signal more when compared to rain. Furthermore, signals transmitted at 1550nm will attenuate the signal less when compared to the other wavelengths of interest. © 2024 IEEE.

关键词： Rain

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Equalizer Zero-Determinant Strategy in Discounted Repeated Stackelberg Asymmetric Game

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Journal of systems Science & Complexity 2024年第1期37卷 184-203页

作者： CHENG Zhaoyang CHEN Guanpu HONG Yiguang Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100049China School of Electrical Engineering and Computer Science KTH Royal Institute of Technology10044 StockholmSweden. Department of Control Science and Engineering Tongji UniversityShanghai 201804China Shanghai Research Institute for Intelligent Autonomous Systems Tongji UniversityShanghai 210201China

This paper focuses on the performance of equalizer zero-determinant(ZD)strategies in discounted repeated Stackelberg asymmetric *** the leader-follower adversarial scenario,the strong Stackelberg equilibrium(SSE)deriving from the opponents’best response(BR),is technically the optimal strategy for the ***,computing an SSE strategy may be difficult since it needs to solve a mixed-integer program and has exponential complexity in the number of *** this end,the authors propose an equalizer ZD strategy,which can unilaterally restrict the opponent’s expected *** authors first study the existence of an equalizer ZD strategy with one-to-one situations,and analyze an upper bound of its performance with the baseline SSE *** the authors turn to multi-player models,where there exists one player adopting an equalizer ZD *** authors give bounds of the weighted sum of opponents’s utilities,and compare it with the SSE ***,the authors give simulations on unmanned aerial vehicles(UAVs)and the moving target defense(MTD)to verify the effectiveness of the proposed approach.

关键词： Discounted repeated Stackelberg asymmetric game equalizer zero-determinant strategy strong Stackelberg equilibrium strategy

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D-Band $\times$ 8 Frequency Multiplier Using Complementary Differential Frequency Doubler

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IEEE Microwave and Wireless Components Letters 2022年 1-4页

作者： Park, Jae-Hyun Yang, Dong-Yeol Choi, Kyu-Jin Kim, Byung-Sung Department of Electrical and Computer Engineering Sungkyunkwan University Suwon South Korea Department of Semiconductor Systems Engineering Sungkyunkwan University Suwon South Korea

A D-band $\times$ 8 frequency multiplier is presented in this letter. The $\times$ 8 frequency multiplier consists of two stages of the newly proposed common load complementary push-push doublers (CL-CPPDs) and one stage of NMOS push-push doubler. The proposed CL-CPPD uses a single load to generate a balanced output with high harmonic rejection (HR) and can be easily cascaded using transformers for a high multiplication ratio with low dc power consumption. The chip is fabricated by using a 40-nm CMOS technology, and it achieves a maximum output power of $-$ 2.48 dBm with an input power of $0$ dBm in the frequency range of 131.2–144.8 GHz. All HRs are over 34 dBc in the frequency range of 131.2–144.8 GHz. The total dc power dissipation is 41.4 mW when supplied from a single voltage of 0.9 V and occupies 0.37 ${\mathrm{mm}}^{2}$ of the chip area. IEEE

关键词： Millimeter waves

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SubmergeStyleGAN: Synthetic Underwater Data Generation with Style Transfer for Domain Adaptation

SubmergeStyleGAN: Synthetic Underwater Data Generation with ...

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2023 International Conference on Digital Image Computing: Techniques and Applications, DICTA 2023

作者： Fathy, Mohamed E. Mohamed, Samer A. Awad, Mohammed I. Munim, Hossam E. Abd El Ain Shams University Mechatronics Engineering Department Faculty of Engineering Egypt Ain Shams University Computer and Systems Engineering Department Faculty of Engineering Egypt University of Bath Department of Electronic and Electrical Engineering Faculty of Engineering and Design United Kingdom

ISBN: (纸本)9798350382204

Underwater computer vision applications are challenged by limited access to annotated underwater datasets. Additionally, convolutional neural networks (CNNs) trained on in-air datasets do not perform well underwater due to the high domain variance caused by the degradation impact of the water column. This paper proposes an air-to-water dataset generator to create visually plausible underwater scenes out of existing in-air datasets. SubmergeStyleGAN, a generative adversarial network (GAN) designed to model attenuation, backscattering, and absorption, utilizes depth maps to apply range-dependent attenuation style transfer. In this work, the generated attenuated images and their corresponding original pairs are used to train an underwater image enhancement CNN. Real underwater datasets were used to validate the proposed approach by assessing various image quality metrics, including UCIQE, UIQM and CCF, as well as disparity estimation accuracy before and after enhancement. SubmergeStyleGAN exhibits a faster and more robust training procedure compared to existing methods in the literature. © 2023 IEEE.

关键词： Image enhancement

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