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The Development Results of the Current SSPS Project and the Progress Status of the Follow-on OHISAMA Project for the Realization of the Operational SSPS

The Development Results of the Current SSPS Project and the ...

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2024 IAF Space Power Symposium at the 75th International Astronautical Congress, IAC 2024

作者： Ijichi, Koichi Yanagawa, Hiroki Yanagi, Kouki Kitabatake, Hidetoslii Iiiada, Hitoini Kasliimura, Osamu Tanaka, Koji Ishikawa, Ryo Honjo, Kazuhiko Iskiimira, Kosei Ogawa, Akihiko Yamaguchi, Koji Japan Space Systems 3-5-8 Shibakoen Minato-ku Tokyo105-0011 Japan Institute of Space and Astronautical Science Japan Aerospace Exploration Agency 3-1-1 Yoshinodai Chuo-ku Kanagawa Sagamihara252-5210 Japan Department of Computer and Network Engineering The University of Electro-Communications 1-5-1 Chofugaoka C-hofu Tokyo1S2-S5S5 Japan Dept. of Modern Mechanical Engineering School of Creative Science and Engineering Waseda University 30401 Okubo Shinjuku-ku Tokyo169-S555 Japan Technologies Development Department IHI Aerospace Co. Ltd. 900 Fujiki Tomioka-shi Gunma-ken370-2398 Japan 1-7-8 Nishi-Kanagawa Kanagawa-ku Kanagawa-ken Yokohama-City221-0822 Japan

ISBN: (纸本)9798331312213

In the year of 2006, the METI of Japan established the SSPS '"USEF model"as the target SSPS configuration to be realized and also established the road map to achieve by the year 2050 based on the conclusion of the discussion based on the concept development, the related FS and also the basic technology development started from the end of 1980th by the committee members consisted of the space related universities and the organizations. Since then, the step-by-step technical development activities started and steadily proceeded according the roadmap for the realization of the ultimate carbon-free and Net-Zero power generation means. The horizontal power beaming and transmission technology development was the first step, and then proceed to the vertical transmission as the next steps. And then more, stepped into the development of the Power Generation and Transmission Panel (PGTP) which is the basic element of the USEF model, improvement of the efficiency of the DC to RP conversion efficiency and also to extend the distance of the WPT to the range of several kilo-meters. This phase stepped into the final year with full success. In parallel with current development phase but according to the road, the demonstration by 180kg class small satellite project called OHISAMA (On-orbit experiment of High-precision beam control using small SAtellite for MicrowAve power transmission) project was started to demonstrate and develop the precise power beaming technology from the LEO to the ground in the JFY of 2025. Our step-by-step approach towards the realization of USEF model according to the roadmap will be introduced with the results of the development activities, and also the progress of the OHISAMA project will be introduced and discussed. © 2024 by the International Astronautical Federation (IAF). All rights reserved.

关键词： Microwave power transmission

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Improving the Transmission Rate by A Two-Phase Hybrid Duplex Scheme for Gaussian Relay Channel

Improving the Transmission Rate by A Two-Phase Hybrid Duplex...

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IEEE International Conference on Communications (ICC)

作者： Jianxin Duan Zhengchuan Chen Zhong Tian Min Wang Li Zhen Dapeng O. Wu Tony Q. S. Quek School of Microelectronics and Communication Engineering. Chongquing University Chongqing China Shaanxi Key Laboratory of Information Communication Network and Security Xi'an University of Posts and Telecommunications Xi'an China School of Optoelectronics Engineering Chongqing University of Posts and Telecommunications Chongqing China Department of Computer Science City University of Hong Kong Hong Kong Information Systems Technology and Design Pillar Singapore University of Technology and Design Singapore

ISBN: (数字)9781728190549

ISBN: (纸本)9781728190556

Combining half-duplex (HD) and full-duplex (FD) is promising in improving the information transmission rate of relay channels. This work proposes a novel two-phase hybrid duplex scheme for Gaussian relay channel where the relay operates in FD mode for a fraction of time and only transmits information for the rest of time. The achievable rate of the proposed hybrid duplex scheme is characterized in detail. Based on the obtained result, a joint time division and power allocation problem is formulated to maximize the achievable rate. In particular, the formulated problem is solved through a two-step optimization method. Firstly, the optimal relay power allocation is obtained for given time division factors. Then, the achievable rate maximization problem is addressed by finding the optimal time division factors. The closed-form expression for the maximal achievable rate is derived for some specific cases. Numerical results show that the proposed two-phase hybrid duplex scheme significantly improves the achievable rate of Gaussian relay channel compared with existing benchmark schemes.

关键词： Closed-form solutions Half-duplex system Optimization methods Information processing Full-duplex system Benchmark testing Resource management

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Stochastic-Robust Planning of networked Hydrogen-Electrical Microgrids: A Study on Induced Refueling Demand

arXiv

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arXiv 2024年

作者： Sun, Xunhang Cao, Xiaoyu Zeng, Bo Zhai, Qiaozhu Başar, Tamer Guan, Xiaohong School of Automation Science and Engineering The Ministry of Education Key Laboratory for Intelligent Networks and Network Security Xi’an Jiaotong University Shaanxi Xi’an710049 China Coordinated Science Laboratory University of Illinois Urbana-Champaign UrbanaIL61801 United States Smart Integrated Energy Department Sichuan Digital Economy Industry Development Research Institute Sichuan Chengdu610037 China Department of Industrial Engineering The Department of Electrical and Computer Engineering University of Pittsburgh PittsburghPA15106 United States Center for Intelligent and Networked Systems Department of Automation Tsinghua University Beijing100084 China

Hydrogen-electrical microgrids are increasingly assuming an important role on the pathway toward decarbonization of energy and transportation systems. This paper studies networked hydrogen-electrical microgrids planning (NHEMP), considering a critical but often-overlooked issue, i.e., the demand-inducing effect (DIE) associated with infrastructure development decisions. Specifically, higher refueling capacities will attract more refueling demand of hydrogen-powered vehicles (HVs). To capture such interactions between investment decisions and induced refueling demand, we introduce a decision-dependent uncertainty (DDU) set and build a trilevel stochastic-robust formulation. The upper-level determines optimal investment strategies for hydrogen-electrical microgrids, the lower-level optimizes the risk-aware operation schedules across a series of stochastic scenarios, and, for each scenario, the middle-level identifies the "worst" situation of refueling demand within an individual DDU set to ensure economic feasibility. Then, an adaptive and exact decomposition algorithm, based on Parametric Column-and-Constraint Generation (PC&CG), is customized and developed to address the computational challenge and to quantitatively analyze the impact of DIE. Case studies on an IEEE exemplary system validate the effectiveness of the proposed NHEMP model and the PC&CG algorithm. It is worth highlighting that DIE can make an important contribution to the economic benefits of NHEMP, yet its significance will gradually decrease when the main bottleneck transits to other system restrictions. Copyright © 2024, The Authors. All rights reserved.

关键词： Stochastic systems

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BOUNDARY ATTENTION MAPPING (BAM): FINE-GRAINED SALIENCY MAPS FOR SEGMENTATION OF BURN INJURIES

arXiv

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arXiv 2023年

作者： Abdolahnejad, Mahla Morzycki, Alex Lee, Justin Ethier, Olivier Chan, Hannah Mo, Anthea Liu, Peter X. Wong, Joshua N. Hong, Colin Joshi, Rakesh Skinopathy Research Skinopathy Inc. North YorkON Canada University of Alberta Hospital EdmontonAB Canada Department of Systems and Computer Engineering Carleton University OttawaON Canada Scarborough Health Network Centenary Hospital ScarboroughON Canada University of Montreal MontrealQC Canada MontrealQC Canada

Burn injuries can result from mechanisms such as thermal, chemical, and electrical insults. A prompt and accurate assessment of burns is essential for deciding definitive clinical treatments. Currently, the primary approach for burn assessments, via visual and tactile observations, is approximately 60%-80% accurate. The gold standard is biopsy and a close second would be non-invasive methods like Laser Doppler Imaging (LDI) assessments, which have up to 97% accuracy in predicting burn severity and the required healing time. In this paper, we introduce a machine learning pipeline for assessing burn severities and segmenting the regions of skin that are affected by burn. Segmenting 2D colour images of burns allows for the injured versus non-injured skin to be delineated, clearly marking the extent and boundaries of the localized burn/region-of-interest, even during remote monitoring of a burn patient. We trained a convolutional neural network (CNN) to classify four severities of burns: SPF (superficial), SPT (superficial partial thickness), DPT (deep partial thickness), and FT (full thickness). We built a saliency mapping method, Boundary Attention Mapping (BAM), that utilises this trained CNN for the purpose of accurately localizing and segmenting the burn regions from skin burn images. We demonstrated the effectiveness of our proposed pipeline through extensive experiments and evaluations using two datasets;1) A larger skin burn image dataset consisting of 1684 skin burn images of four burn severities, 2) An LDI dataset that consists of a total of 184 skin burn images with their associated LDI scans. The CNN trained using the first dataset achieved an average F1-Score of 78% and micro/macro- average ROC of 85% in classifying the four burn severities. Moreover, a comparison between the BAM results and LDI results for measuring injury boundary showed that the segmentations generated by our method achieved 91.60% accuracy, 78.17% sensitivity, and 93.37% specificity. ©

关键词： Mapping

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Device Activity Detection in mMTC with Low-Resolution ADC: A New Protocol

arXiv

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arXiv 2023年

作者： Wang, Zhaorui Liu, Ya-Feng Wang, Ziyue Liu, Liang Pan, Haoyuan Cui, Shuguang The Future Network of Intelligence Institute The School of Science and Engineering The Chinese University of Hong Kong Shenzhen518172 China The State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China The Department of Electronic and Information Engineering The Hong Kong Polytechnic University Hong Kong College of Computer Science and Software Engineering Shenzhen University Shenzhen China

This paper investigates the effect of low-resolution analog-to-digital converters (ADCs) on device activity detection in massive machine-type communications (mMTC). The low-resolution ADCs induce two challenges on the device activity detection compared with the traditional setup with the assumption of infinite ADC resolution. First, the codebook design for signal quantization by the low-resolution ADC is particularly important since a good design of the codebook can lead to small quantization error on the received signal, which in turn has significant influence on the activity detector performance. To this end, prior information about the received signal power is needed, which depends on the number of active devices K. This is sharply different from the activity detection problem in traditional setups, in which the knowledge of K is not required by the BS as a prerequisite. Second, the covariance-based approach achieves good activity detection performance in traditional setups while it is not clear if it can still achieve good performance in this paper. To solve the above challenges, we propose a communication protocol that consists of an estimator for K and a detector for active device identities: 1) For the estimator, the technical difficulty is that the design of the ADC quantizer and the estimation of K are closely intertwined and doing one needs the information/execution from the other. We propose a progressive estimator which iteratively performs the estimation of K and the design of the ADC quantizer;2) For the activity detector, we propose a custom-designed stochastic gradient descent algorithm to estimate the active device identities. Numerical results demonstrate the effectiveness of the communication protocol. © 2023, CC BY.

关键词： Stochastic systems

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Lightning-Fast Dual-Layer Lossless Coding for Radiance Format High Dynamic Range Images

arXiv

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arXiv 2023年

作者： Suzuki, Taizo Yukikata, Sara Yang, Kai Yoshida, Taichi The Institute of Engineering Information and Systems University of Tsukuba Ibaraki305-8573 Japan Sky Co. Ltd. Tokyo108-0075 Japan Da-Jiang Innovations Science and Technology Japan Co. Ltd. Tokyo108-0075 Japan The Department of Computer and Network Engineering Graduate School of Informatics and Engineering The University of Electro-Communications Tokyo182-8585 Japan

This paper proposes a fast dual-layer lossless coding for high dynamic range images (HDRIs) in the Radiance format. The coding, which consists of a base layer and a lossless enhancement layer, provides a standard dynamic range image (SDRI) without requiring an additional algorithm at the decoder and can losslessly decode the HDRI by adding the residual signals (residuals) between the HDRI and SDRI to the SDRI, if desired. To suppress the dynamic range of the residuals in the enhancement layer, the coding directly uses the mantissa and exponent information from the Radiance format. To further reduce the residual energy, each mantissa is modeled (estimated) as a linear function, i.e., a simple linear regression, of the encoded-decoded SDRI in each region with the same exponent. This is called simple linear regressive mantissa estimator. Experimental results show that, compared with existing methods, our coding reduces the average bitrate by approximately 1.57-6.68 % and significantly reduces the average encoder implementation time by approximately 87.13-98.96 %. Copyright © 2023, The Authors. All rights reserved.

关键词： Image enhancement

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Discovering collective narratives shifts in online discussions

arXiv

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arXiv 2023年

作者： Zhao, Wanying Guo, Fiona Lerman, Kristina Ahn, Yong-Yeol Center for Complex Networks and Systems Research Luddy School of Informatics Computing and Engineering Indiana University United States Department of Computer Science University of Southern California United States Information Sciences Institute University of Southern California United States Network Science Institute Indiana University BloomingtonIN United States

Narrative is a foundation of human cognition and decision making. Because narratives play a crucial role in societal discourses and spread of misinformation and because of the pervasive use of social media, the narrative dynamics on social media can have profound societal impact. Yet, systematic and computational understanding of online narratives faces critical challenge of the scale and dynamics;how can we reliably and automatically extract narratives from massive amount of texts? How do narratives emerge, spread, and die? Here, we propose a systematic narrative discovery framework that fill this gap by combining change point detection, semantic role labeling (SRL), and automatic aggregation of narrative fragments into narrative networks. We evaluate our model with synthetic and empirical data-two Twitter corpora about COVID-19 and 2017 French Election. Results demonstrate that our approach can recover major narrative shifts that correspond to the major events. © 2023, CC BY-NC-ND.

关键词： Decision making

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A Timing-Based Framework for Designing Resilient Cyber-Physical systems under Safety Constraint

arXiv

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arXiv 2022年

作者： Al Maruf, Abdullah Niu, Luyao Clark, Andrew Mertoguno, J. Sukarno Poovendran, Radha Network Security Lab. Department of Electrical and Computer Engineering University of Washington P.O. Box 1212 SeattleWA98195-2500 United States Network Security Lab. Department of Electrical and Computer Engineering University of Washington SeattleWA98195-2500 United States Electrical and Systems Engineering Department McKelvey School of Engineering Washington University St. LouisMO63130 United States School of Cybersecurity and Privacy Georgia Institute of Technology AtlantaGA30332 United States

Cyber-physical systems (CPS) are required to satisfy safety constraints in various application domains such as robotics, industrial manufacturing systems, and power systems. Faults and cyber attacks have been shown to cause safety violations, which can damage the system and endanger human lives. Resilient architectures have been proposed to ensure safety of CPS under such faults and attacks via methodologies including redundancy and restarting from safe operating conditions. The existing resilient architectures for CPS utilize different mechanisms to guarantee safety, and currently there is no approach to compare them. Moreover, the analysis and design undertaken for CPS employing one architecture is not readily extendable to another. In this paper, we propose a timing-based framework for CPS employing various resilient architectures and develop a common methodology for safety analysis and computation of control policies and design parameters. Using the insight that the cyber subsystem operates in one out of a finite number of statuses, we first develop a hybrid system model that captures CPS adopting any of these architectures. Based on the hybrid system, we formulate the problem of joint computation of control policies and associated timing parameters for CPS to satisfy a given safety constraint and derive sufficient conditions for the solution. Utilizing the derived conditions, we provide an algorithm to compute control policies and timing parameters relevant to the employed architecture. We also note that our solution can be applied to a wide class of CPS with polynomial dynamics and also allows incorporation of new architectures. We verify our proposed framework by performing a case study on adaptive cruise control of vehicles. © 2022, CC BY.

关键词： Cyber Physical System

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Joint Design of Radar Receive Filter and Unimodular ISAC Waveform with Sidelobe Level Control

arXiv

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arXiv 2025年

作者： Zhang, Kecheng Liu, Ya-Feng Wang, Zhongbin Yuan, Weijie Keskin, Musa Furkan Wymeersch, Henk Xia, Shuqiang School of System Design and Intelligent Manufacturing The Shenzhen Key Laboratory of Robotics and Computer Vision Southern University of Science and Technology Shenzhen518055 China State Key Laboratory of Scientific and Engineering Computing Institute of Computational Mathematics and Scientific/Engineering Computing Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing100190 China Department of Electrical Engineering Chalmers University of Technology Gothenburg41296 Sweden ZTE Corporation The State Key Laboratory of Mobile Network and Mobile Multimedia Technology Shenzhen518055 China

Integrated sensing and communication (ISAC) has been considered a key feature of next-generation wireless networks. This paper investigates the joint design of the radar receive filter and dual-functional transmit waveform for the multiple-input multiple-output (MIMO) ISAC system. While optimizing the mean square error (MSE) of the radar receive spatial response and maximizing the achievable rate at the communication receiver, besides the constraints of full-power radar receiving filter and unimodular transmit sequence, we control the maximum range sidelobe level, which is often overlooked in existing ISAC waveform design literature, for better radar imaging performance. To solve the formulated optimization problem with convex and nonconvex constraints, we propose an inexact augmented Lagrangian method (ALM) algorithm. For each subproblem in the proposed inexact ALM algorithm, we custom-design a block successive upper-bound minimization (BSUM) scheme with closed-form solutions for all blocks of variable to enhance the computational efficiency. Convergence analysis shows that the proposed algorithm is guaranteed to provide a stationary and feasible solution. Extensive simulations are performed to investigate the impact of different system parameters on communication and radar imaging performance. Comparison with the existing works shows the superiority of the proposed algorithm. © 2025, CC BY-NC-SA.

关键词： Mean square error

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Universal spatial inflation of human mobility

arXiv

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arXiv 2024年

作者： Zhong, Lu Dong, Lei Wang, Qi Song, Chaoming Gao, Jianxi Department of Computer Science Rensselaer Polytechnic Institute TroyNY United States Network Science and Technology Center Rensselaer Polytechnic Institute TroyNY United States Institute of Remote Sensing and Geographical Information Systems School of Earth and Space Sciences Peking University Beijing China Department of Civil and Environmental Engineering Northeastern University BostonMA United States Department of Physics University of Miami Coral GablesFL United States

Human mobility patterns reflect our interactions with the environment. While extensive research has focused on specific spatial scales—such as intracity or intercity— universal mobility characteristics across various scales remain largely unexplored. Here, by partitioning trajectories into modules through network community detection, we find that the geospatial extent of modules increases sublinearly with distance from home, indicating a universal inflation law that holds across three orders of magnitude and is independent of demographic factors. Our further investigation highlights a potential connection between this inflation law and hierarchical urban structure. These findings deepen our understanding of human mobility dynamics, with implications for urban planning, tourism management, and epidemic intervention. Copyright © 2024, The Authors. All rights reserved.

关键词： Inflation

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