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Cross-layer transmission and energy scheduling under full-duplex energy harvesting wireless OFDM joint transmission

Science China(Information Sciences) 2016年第10期59卷 136-151页

作者： Hongjia LI Zejue WANG Dan HU Song CI Zhen XU State Key Lab of Information Security Institute of Information EngineeringChinese Academy of Sciences Cisco System Incorporated Department of Computer and Electronics Engineering University of Nebraska-Lincoln

This paper studies the design of the optimal and online cross-layer transmission and energy schedulings for a full-duplex energy harvesting wireless orthogonal frequency division multiplexing(OFDM) joint transmissions. Supported by today’s power management integrated circuit, the full-duplex energy harvesting system becomes a reality, which can overcome the transmission time loss problem caused by the half-duplex constraint of the energy storage unit(ESU) in the serial Harvest-Store-Use system. However, its corresponding modeling is still unexplored. Therefore, the full-duplex energy harvesting system is first modeled and proved to be equivalent to a composition of energy behavior models of Harvest-Store-Use in fine-time granularity. Then, the convex optimization problem of cross-layer transmission and energy scheduling is formulated with the objective to maximize the sum of transmission throughput during successively multiple time units, which takes into account the temporal variance of energy harvesting rates and channel states, and the limited capacity of *** optimal power allocation with three dimensions of time, channel and antenna is solved by utilizing the dual decomposition method with the pre-known temporal variance, and the corresponding result of the system throughput provides the theoretical upper bound. Finally, to reduce the throughput degradation caused by channel state prediction errors, a non-convex online scheduling problem is formulated as the classical energy efficiency format. It is transformed into a convex optimization problem by exploiting the properties of fractional programming, and then, an efficiently iterative solution is designed. Numerical results show that the average throughput of the online algorithm is 24% greater than that of existing time-energy adaptive water-filling algorithm. The degradation of the average throughput is less than 19% with probability 90%, even as the channel prediction error reaches 20%. These results pro

关键词： energy harvesting wireless communication power allocation joint transmission optimization green communication

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Automatic vector-based road structure mapping using multi-beam lidar

arXiv

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arXiv 2018年

作者： He, Xudong Zhao, Junqiao Sun, Lu Huang, Yewei Zhang, Xinglian Li, Jun Ye, Chen Key Laboratory of Embedded System and Service Computing Tongji University Ministry of Education Shanghai Department of Computer Science and Technology School of Electronics and Information Engineering Tongji University Shanghai School of Surveying and Geo-Informatics Tongji University Shanghai China School of Automotive Studies Tongji University Shanghai China

In this paper, we studied a SLAM method for vector-based road structure mapping using multi-beam LiDAR. We propose to use the polyline as the primary mapping element instead of grid cell or point cloud, because the vector-based representation is precise and lightweight, and it can directly generate vector-based High-Definition (HD) driving map as demanded by autonomous driving systems. We explored: 1) the extraction and vectorization of road structures based on local probabilistic fusion. 2) the efficient vector-based matching between frames of road structures. 3) the loop closure and optimization based on the pose-graph. In this study, we took a specific road structure, the road boundary, as an example. We applied the proposed matching method in three different scenes and achieved the average absolute matching error of 0.07 m. We further applied the mapping system to the urban road with the length of 860 meters and achieved an average global accuracy of 0.466 m without the help of high precision GPS. Copyright © 2018, The Authors. All rights reserved.

关键词： Mapping

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Self-Awareness for Autonomous systems

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PROCEEDINGS OF THE IEEE 2020年第7期108卷 971-975页

作者： Dutt, Nikil Regazzoni, Carlo S. Rinner, Bernhard Yao, Xin Nikil Dutt (Fellow IEEE) received the Ph.D. degree from the University of Illinois at Urbana–Champaign Champaign IL USA in 1989.""He is currently a Distinguished Professor of computer science (CS) cognitive sciences and electrical engineering and computer sciences (EECS) with the University of California at Irvine Irvine CA USA. He is a coauthor of seven books. His research interests include embedded systems electronic design automation (EDA) computer architecture distributed systems healthcare Internet of Things (IoT) and brain-inspired architectures and computing.""Dr. Dutt is a Fellow of ACM. He was a recipient of the IFIP Silver Core Award. He has received numerous best paper awards. He serves as the Steering Committee Chair of the IEEE/ACM Embedded Systems Week (ESWEEK). He is also on the steering organizing and program committees of several premier EDA and embedded system design conferences and workshops. He has served on the Editorial Boards for the IEEE Transactions on Very Large Scale Integration (VLSI) Systems and the ACM Transactions on Embedded Computing Systems and also previously served as the Editor-in-Chief (EiC) for the ACM Transactions on Design Automation of Electronic Systems. He served on the Advisory Boards of the IEEE Embedded Systems Letters the ACM Special Interest Group on Embedded Systems the ACM Special Interest Group on Design Automationt and the ACM Transactions on Embedded Computing Systems. Carlo S. Regazzoni (Senior Member IEEE) received the M.S. and Ph.D. degrees in electronic and telecommunications engineering from the University of Genoa Genoa Italy in 1987 and 1992 respectively.""He is currently a Full Professor of cognitive telecommunications systems with the Department of Electrical Electronics and Telecommunication Engineering and Naval Architecture (DITEN) University of Genoa and a Co-Ordinator of the Joint Doctorate on Interactive and Cognitive Environments (JDICE) international Ph.D. course started initially as EU Erasmus Mundus Project and

Autonomous systems are able to make decisions and potentially take actions without direct human intervention, which requires some knowledge about the system and its environment as well as goal-oriented reasoning. In computer systems, one can derive such behavior from the concept of a rational agent with autonomy (“control over its own actions”), reactivity (“react to events from the environment”), proactivity (“act on its own initiative”), and sociality (“interact with other agents”) as fundamental properties \n[1]\n. Autonomous systems will undoubtedly pervade into our everyday lives, and we will find them in a variety of domains and applications including robotics, transportation, health care, communications, and entertainment to name a few. \nThe articles in this month’s special issue cover concepts and fundamentals, architectures and techniques, and applications and case studies in the exciting area of self-awareness in autonomous systems.

关键词： Special issues and sections Autonomous systems Self-aware Robot sensing systems Computational modeling

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An optimized energy management strategy for fuel cell hybrid vehicles

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IOP Conference Series: Materials Science and engineering 2019年第4期612卷

作者： Wenxin Xiao Lei Wang Dongyin Liu Wenwen Zhang Chinese-German College Tongji University Shanghai China Department of Electrical and Computer Engineering Technische Universität München Munich Germany Research Center of Control Science and Intelligent System University of Electronic Science and Technology of China Chengdu China College of Electronics and Information Engineering Tongji University Shanghai China

Fuel cell hybrid vehicles are environmentally friendly and have good development prospects. Their energy management is very important, but there are currently few studies on this topic. In this paper, an optimized energy management strategy specifically applied to fuel cell hybrid vehicles is proposed. Fuel cell hybrid vehicles have some different characteristics from ordinary hybrid vehicles, which need to be considered in energy management. For the fuel cell to remain activated during driving, its output power must remain above a minimum power. In addition, it takes some time for the fuel cell to start up. These characteristics are considered in the vehicle model. The energy management strategy proposed in this paper maximizes energy use efficiency by controlling the SOC value of the battery. The SOC value of the battery is in the proper range during driving. At high speeds, fuel is consumed as a source of energy and the battery is charged to keep its SOC at a high level. When approaching the destination or when the vehicle is traveling at a low speed, the battery is discharged to reduce fuel consumption. Applying this strategy to the ECE-15 and EUDCL environments, the simulation results show that this optimized energy management strategy improves the energy efficiency of the fuel cell and enables the battery to operate at the appropriate power.

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Water extraction of SAR image based on region merging algorithm

Water extraction of SAR image based on region merging algori...

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2017 International Applied Computational Electromagnetics Society Symposium in China, ACES-China 2017

作者： Zheng, Xinhong Chen, Jiaqi Zhang, Shilin Chen, Jiansheng School of Earth Sciences and Engineering Hohai University Nanjing210098 China College of Computer and Information Hohai University Nanjing210098 China Department of Space Microwave Remote Sensing System Institute of Electronics Chinese Academy of Sciences Beijing100190 China

ISBN: (纸本)9780996007856

SAR (Synthetic aperture radar) has the advantages that it can be observed all day long and all weather. Space borne SAR is able to observe the target area periodically, therefore the extraction of lakes using SAR image is more and more widely used. The detection and update of lake plays an important role in water resources managing, water environment monitoring and watershed management. The traditional image segmentation method can hardly extract the lake quickly and accurately due to the impact of the wind, the differences of backscattering characteristic and the influence of noise on SAR images. Taking Hulun Lake as an example, this paper presents a combination of coarse and fine based region merging algorithm for SAR image to extract lakes automatically. The results show that the improved algorithm increases the accuracy of lake surface extraction and reduces the time complexity of region merging. © 2017 Applied Computational Electromagnetics Society.

关键词： Synthetic aperture radar

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A 0.015-mm$^{\text{2}}$ Inductorless 32-GHz Clock Generator With Wide Frequency-Tuning Range in 28-nm CMOS Technology

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IEEE Transactions on Circuits and systems II: Express Briefs 2017年第6期64卷 655-659页

作者： Gyu-Seob Jeong Wooseok Kim Jaejin Park Taeik Kim Hojin Park Deog-Kyoon Jeong Department of Electrical and Computer Engineering Seoul National University Seoul Korea System Latent Semantic Indexing (LSI) Business Unit Samsung Electronics Suwon Korea

This brief illustrates the design of an inductorless high-speed clock generator. Compared to inductance-capacitance (LC) oscillators, ring oscillators are used in order to achieve a wide frequency-tuning range with a small chip area. By employing a cascaded phase-locked loop (PLL) architecture, the phase noise of the oscillator can be effectively suppressed. The first PLL is implemented with high-voltage devices under 1.8-V supply to provide a clean reference for the second PLL. The second PLL consists of only low-voltage devices, with a supply voltage of 0.9 V for high-speed operation. Following the second PLL, a clock doubler multiplies the PLL output clock by a factor of 2, which avoids power-consuming high-frequency clock dividers. In order to minimize any mismatch effects, special layout techniques are employed for the second voltage-controlled oscillator and the clock doubler. The prototype chip was fabricated in 28-nm complementary metal oxide semiconductor (CMOS) technology, and it occupies an active area of only 0.015 mm 2 . The proposed PLL achieves a maximum output frequency of 32 GHz and consumes a total power of 30 mW, exhibiting a power efficiency of 0.9 mW/GHz.

关键词： Clocks Phase locked loops Tuning Voltage-controlled oscillators Ring oscillators Phase noise

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Design and Control of Single-Phase Grid-Connected Photovoltaic Microinverter with Reactive Power Support Capability

Design and Control of Single-Phase Grid-Connected Photovolta...

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International Power electronics Conference

作者： Geon-Hong Min Kyung-Hwan Lee Jung-Ik Ha Myong Hwan Kim Department of Electrical and Computer Engineering Seoul National University Seoul Republic of Korea Solar System Development Team Solar R&D Lab LG Electronics Gumi Republic of Korea

This paper proposes a single-phase photovoltaic (PV) microinverter capable of supplying reactive power to the grid. In the past, researchers mainly focused on obtaining high efficiency, low cost, and high boost ratio. However, as the solar power generation has increased in recent years, the grid regulations have been changed so that PV inverters provide reactive power for the grid stability. Therefore, the proposed PV microinverter is constructed by the bidirectional boost/buck dc-dc converter for reactive power support and achieving high step-up ratio by using coupled inductors. In addition to the design guideline, this paper presents the control strategy of the proposed microinverter. Unlike traditional two-stage microinverters, the dc-link voltage is shaped like the rectified grid voltage. The experimental results verify that the 320-W laboratory prototype can supply reactive power and reaches 96.5% California Energy Commission (CEC) efficiency at unity power factor operation.

关键词： Microinverter Photovoltaic (PV) Reactive power Single-stage inverter

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Intrinsic 1T̕ phase induced in atomically thin 2H-MoTe2 by a single terahertz pulse

arXiv

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arXiv 2019年

作者： Shi, Jiaojian Bie, Ya-Qing Zong, Alfred Fang, Shiang Chen, Wei Han, Jinchi Cao, Zhaolong Zhang, Yong Taniguchi, Takashi Watanabe, Kenji Bulović, Vladimir Kaxiras, Efthimios Baldini, Edoardo Jarillo-Herrero, Pablo Nelson, Keith A. Department of Chemistry Massachusetts Institute of Technology CambridgeMA02139 United States Department of Physics Massachusetts Institute of Technology CambridgeMA02139 United States State Key Lab of Optoelectronic Materials and Technologies Guangdong Province Key Laboratory of Display Material and Technology School of Electronics and Information Technology Sun Yat-sen University Guangzhou510275 China Department of Chemistry University of California BerkeleyCA94720 United States Department of Physics Harvard University CambridgeMA02138 United States Department of Physics and Astronomy Center for Materials Theory Rutgers University PiscatawayNJ08854 United States Department of Electrical Engineering and Computer Science Massachusetts Institute of Technology CambridgeMA02139 United States Center for Materials Science & Engineering Massachusetts Institute of Technology CambridgeMA02139 United States International Center for Materials Nanoarchitectonics National Institute for Materials Science 1-1 Namiki Tsukuba305-0044 Japan Research Center for Functional Materials National Institute for Materials Science 1-1 Namiki Tsukuba305-0044 Japan Department of Physics Center for Complex Quantum System The University of Texas at Austin AustinTX78712 United States

Polymorphic transitions in layered transition metal dichalcogenides provide an excellent platform for discovering exotic phenomena associated with metastable states, ranging from topological phase transitions1 to enhanced superconductivity2. In particular, the transition from 2H to 1T0-MoTe2, which was thought to be induced by high-energy photon irradiation3–5 among many other means6–9, has been intensely studied for its technological relevance in nanoscale transistors3. Despite the remarkable electrical performance arising from this 2H-to-1T0 transition, it remains controversial whether a crystalline 1T0 phase is produced because optical signatures of this putative transition are found to be associated with the formation of elemental Te clusters instead10,11. Here, we demonstrate the creation of an intrinsic 1T0 lattice after irradiating a mono- or few-layer 2H-MoTe2 with a single field-enhanced terahertz pulse, whose low photon energy limits possible structural damage by optical pulses. To visualize the temporal evolution of this irreversible transition, we further develop a single-shot terahertz pump-second harmonic probe technique, and we find that the transition out of the 2H phase occurs within 10 ns after photoexcitation. Our results not only resolve the long-standing debate over the light-induced polymorphic transition in MoTe2, they also highlight the unique capability of strong-field terahertz pulses in manipulating the structure of quantum materials. Copyright © 2019, The Authors. All rights reserved.

关键词： Transition metals

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Origin of temperature and field dependence of magnetic skyrmion size in ultrathin nanodots

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Physical Review B 2018年第6期97卷 060402(R)-060402(R)页

作者： R. Tomasello K. Y. Guslienko M. Ricci A. Giordano J. Barker M. Carpentieri O. Chubykalo-Fesenko G. Finocchio Department of Engineering Polo Scientifico Didattico di Terni University of Perugia 50100 Terni Italy Departamento Física de Materiales Universidad del País Vasco UPV/EHU 20018 San Sebastián Spain IKERBASQUE the Basque Foundation for Science 48013 Bilbao Spain Department of Computer Science Modeling Electronics and System Science University of Calabria I-87036 Rende Italy Department of Mathematical and Computer Sciences Physical Sciences and Earth Sciences University of Messina 98166 Messina Italy Institute for Materials Research Tohoku University 980-8577 Sendai Japan Department of Electrical and Information Engineering Politecnico di Bari 70125 Bari Italy Instituto de Ciencia de Materiales de Madrid CSIC Cantoblanco 28049 Madrid Spain

Understanding the physical properties of magnetic skyrmions is important for fundamental research with the aim to develop new spintronic device paradigms where both logic and memory can be integrated at the same level. Here, we show a universal model based on the micromagnetic formalism that can be used to study skyrmion stability as a function of magnetic field and temperature. We consider ultrathin, circular ferromagnetic magnetic dots. Our results show that magnetic skyrmions with a small radius—compared to the dot radius—are always metastable, while large radius skyrmions form a stable ground state. The change of energy profile determines the weak (strong) size dependence of the metastable (stable) skyrmion as a function of temperature and/or field.

关键词： Ferromagnetism Skyrmions Spintronics Ferromagnets Magnetic multilayers Landau-Lifschitz-Gilbert equation Micromagnetic modeling Monte Carlo methods

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Low-noise 750-MHz spaced Yb:fiber frequency combs

arXiv

引用

arXiv 2018年

作者： MA, YUXUAN XU, BO ISHII, HIROTAKA MENG, FEI NAKAJIMA, YOSHIAKI MATSUSHIMA, ISAO SCHIBLI, THOMAS R. ZHANG, ZHIGANG MINOSHIMA, KAORU 1-5-1 Chofugaoka Chofu Tokyo182-8585 Japan State Key Laboratory of Advanced Optical Communication System and Networks School of Electronics Engineering and Computer Science Peking University Beijing100871 China Project 1-5-1 Chofugaoka Chofu Tokyo182-8585 Japan Department of Physics University of Colorado at Boulder 2000 Colorado Avenue BoulderCO80309-0390 United States

Growing interest of frequency combs is stimulating the development of high repetition rate combs. However, increasing the repetition rate to ∼GHz levels while maintaining tight phase locking to an optical reference w... 详细信息

关键词： Fibers

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