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Reliability of DC-link capacitor in pulsed power supply for accelerator magnet

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Nuclear science and Techniques 2024年第9期35卷 28-40页

作者： Jie Wang Da-Qing Gao Wan-Zeng Shen Hong-Bin Yan Li-Jun Mao Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China School of Nuclear science and technology Lanzhou UniversityLanzhou 730000China School of Nuclear science and technology University of Chinese Academy of SciencesBeijing 100049China

Capacitors are widely used in pulsed magnet power supplies to reduce ripple voltage,store energy,and decrease power *** this study,DC-link capacitors in pulsed power supplies were *** deriving an analytical method for the capacitor current on the H-bridge topology side,the root-mean-square value of the capacitor current was calculated,which helps in selecting the DC-link *** proposed method solves this problem quickly and with high *** current reconstruction of the DC-link capacitor is proposed to avoid structural damage in the capacitor’s current measurement,and the capacitor’s hotspot temperature and temperature rise are calculated using the FFT *** test results showed that the error between the calculated and measured temperature increases was within 1.5℃.Finally,the lifetime of DC-link capacitors was predicted based on Monte Carlo *** proposed method can evaluate the reliability of DC-link capacitors in a non-isolated switching pulsed power supply for accelerators and is also applicable to film capacitors.

关键词： Aluminum electrolytic capacitor DC-link current DC–DC power converter Hotspot temperature

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The Exchange Attack and the Mixture Differential Attack Revisited: From the Perspective of Automatic Evaluation

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Chinese Journal of Electronics 2024年第1期33卷 19-29页

作者： Kexin QIAO Zhiyu ZHANG Zhongfeng NIU Liehuang ZHU School of Cyberspace science and technology Beijing Institute of Technology State Key Laboratory of Cryptology Institute of Information Engineering Chinese Academy of Sciences School of Cryptography University of Chinese Academy of Sciences

Recent results show that the differential properties within quadruples boom as a new inspiration in cryptanalysis of Advanced Encryption Standard(AES)-like constructions. These methods include the exchange attack proposed in Asiacrypt’19, the mixture differential attack proposed in To SC’18, etc., where the essential properties are obtained by manually scrutinizing the structures of the AES-like constructions. This paper presents a novel framework and an automatic tool based on mixed integer linear programming to search for mixture differential distinguishers for general constructions. This framework considers what equality patterns among quadruples can make a distinguisher and traces how the patterns propagate through cipher components with accurate probability *** this tool, a 5-round AES distinguishing attack with lower complexity and more 6-round distinguishing attacks in the chosen plaintext scenarios are deduced. We prove that no exchange-type or mixture differential distinguisher exists for 7 and above rounds AES if the details of the Sbox and Mix Columns matrix are not taken into account.

关键词： Ciphers Estimation Encryption Mixed integer linear programming Complexity theory Standards

From 0D to 3D:Hierarchical structured high-performance free-standing silicon anodes based on binder-induced topological network architecture

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Journal of Energy Chemistry 2024年第6期93卷 16-23,I0002页

作者： Yihong Tong Ruicheng Cao Guanghui Xu Yifeng Xia Hongyuan Xu Hong Jin Hui Xu Xi’an Jiaotong University Suzhou academy Suzhou 215123JiangsuChina Nano science and technology Institute University of Science and Technology of ChinaSuzhou 215123JiangsuChina

Free-standing silicon anodes with high proportion of active materials have aroused great attention;however,the mechanical stability and electrochemical performance are severely ***,to resolve the appeal issues,a free-standing anode with a"corrugated paper"shape on micro-scale and a topological crosslinking network on the submicron and nano-scale is ***,an integrated three-dimensional electrode structure is constructed based on robust carbon nanotubes network with firmly anchored SiNPs via forming interlocking *** which,the hierarchical interlocking structure is achieved by directional induction of the binder,which ensures well integration during cycling so that significantly enhances mechanical stability as well as electronic and ionic conductivity of *** from it,this anode exhibits outsta nding performance under harsh service conditions including high Si loading,ultrahigh areal capacity(33.2 mA h cm^(-2)),and high/low temperatures(-15-60℃),which significantly extends its practical ***,the optimization mechanism of this electrode is explored to verify the crack-healing and structure-integration maintaining along cycling via a unique self-stabilization ***,from both the fundamental and engineering views,this strategy offers a promising path to produce high-performance free-standing electrodes for flexible device applications especially facing volume effect challenges.

关键词： Topological network Self-stabilization Flexibility Free-standing Silicon anode

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Universal and efficient hybrid modeling and direct slicing method for additive manufacturing processes

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Advances in Manufacturing 2024年第2期12卷 300-316页

作者： Sen-Lin Wang Li-Chao Zhang Chao Cai Ming-Kai Tang Si Chen Jiang Huang Yu-Sheng Shi State Key Laboratory of Materials Processing and Die and Mould technology Huazhong University of Science and TechnologyWuhan430074People’s Republic of China School of machinery and Automation Wuhan University of Science and TechnologyWuhan430081People’s Republic of China

Model design and slicing contour generation in additive manufacturing(AM)data processing face challenges in terms of efficiency and scalability when stereolithography files generated by complex functionally graded structures have millions of *** paper proposes a hybrid modeling and direct slicing method for AM to efficiently construct and handle complex three-dimensional(3D)*** 3D solids,including conformal multigradient structures,were uniformly described using a small amount of data via signed distance *** hybrid representations were quickly discretized into numerous disordered directed lines using an improved marching squares *** establishing a directional HashMap to construct the topological relationship between lines,a connecting algorithm with linear time complexity is proposed to generate slicing contours for *** method replaces the mesh reconstruction and Boolean operation stages and can efficiently construct complex conformal gradient models of arbitrary topologies through hybrid ***,the time and memory consumption of direct slicing are much lower than those of previous methods when handling hybrid models with hundreds of millions of faces after mesh reconstruction.

关键词： Additive manufacturing(AM) Hybrid modeling Direct slicing Signed distance field

OpBench: an operator-level GPU benchmark for deep learning

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science China(Information sciences) 2024年第9期67卷 76-87页

作者： Qingwen GU Bo FAN Zhengning LIU Kaicheng CAO Songhai ZHANG Shimin HU Department of Computer science and technology Tsinghua University National Innovation Institute of Defense technology Academy of Military Science Beijing Fitten technology Co. Ltd.

Operators(such as Conv and ReLU) play an important role in deep neural networks. Every neural network is composed of a series of differentiable operators. However, existing AI benchmarks mainly focus on accessing model training and inference performance of deep learning systems on specific models. To help GPU hardware find computing bottlenecks and intuitively evaluate GPU performance on specific deep learning tasks, this paper focuses on evaluating GPU performance at the operator level. We statistically analyze the information of operators on 12 representative deep learning models from six prominent AI tasks and provide an operator dataset to show the different importance of various types of operators in different networks. An operator-level benchmark, OpBench, is proposed on the basis of this dataset, allowing users to choose from a given range of models and set the input sizes according to their demands. This benchmark offers a detailed operator-level performance report for AI and hardware developers. We also evaluate four GPU models on OpBench and find that their performances differ on various types of operators and are not fully consistent with the performance metric FLOPS(floating point operations per second).

关键词： deep learning operator benchmark model benchmark GPU performance analysis deep neural networks

An efficient schedulability analysis based on worst-case interference time for real-time systems

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science China(Information sciences) 2024年第9期67卷 88-104页

作者： Hongbiao LIU Mengfei YANG Lei QIAO Xi CHEN Jian GONG School of Computer science and technology Xidian University China academy of Space technology Beijing Institute of Control Engineering

Real-time systems are widely implemented in the Internet of Things(IoT) and safety-critical systems, both of which have generated enormous social value. Aiming at the classic schedulability analysis problem in real-time systems, we proposed an exact Boolean analysis based on interference(EBAI) for schedulability analysis in real-time systems. EBAI is based on worst-case interference time(WCIT), which considers both the release jitter and blocking time of the task. We improved the efficiency of the three existing tests and provided a comprehensive summary of related research results in the field. Abundant experiments were conducted to compare EBAI with other related results. Our evaluation showed that in certain cases, the runtime gain achieved using our analysis method may exceed 73% compared to the stateof-the-art schedulability test. Furthermore, the benefits obtained from our tests grew with the number of tasks, reaching a level suitable for practical application. EBAI is oriented to the five-tuple real-time task model with stronger expression ability and possesses a low runtime overhead. These characteristics make it applicable in various real-time systems such as spacecraft, autonomous vehicles, industrial robots, and traffic command systems.

关键词： five-tuple real-time task model real-time system spacecraft Internet of Things exact schedulability analysis worst-case interference time

A New Random Sampling Method and Its Application in Improving Progressive BKZ Algorithm

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Journal of Systems science & Complexity 2024年第5期37卷 2262-2292页

作者： SUN Minghao WANG Shixiong CHEN Hao QU Longjiang College of sciences National University of Defense Technology academy of Military sciences College of Information science and technology/Cyber Security Jinan University

Random sampling algorithm was proposed firstly by Schnorr in 2003 to find short lattice vectors, as an alternative to enumeration. The follow-up developments in random sampling were mainly proposed by Fukase and Kashiwabara in 2015 and Aono and Nguyen in 2017. Although they extended the sampling space compared to Schnorr's work through the natural number representation, they did not show how to sample specifically in practice and what vectors should be sampled, in order to find short enough lattice vectors. In this paper, the authors firstly introduce a practical random sampling algorithm under some reasonable assumptions which can find short enough lattice vectors ***, as an application of this new random sampling algorithm, the authors show that it can improve the performance of progressive BKZ algorithm in practice. Finally, the authors solve the Darmstadt's Lattice Challenge and get a series of new records in the dimension from 500 to 825, using the improved progressive BKZ algorithm.

关键词： Darmstadt’s lattice challenge lattice lattice reduction algorithm post-quantum cryptography random sampling

Heavy ion energy influence on multiple-cell upsets in small sensitive volumes:from standard to high energies

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Nuclear science and Techniques 2024年第5期35卷 109-121页

作者： Yang Jiao Li-Hua Mo Jin-Hu Yang Yu-Zhu Liu Ya-Nan Yin Liang Wang Qi-Yu Chen Xiao-Yu Yan Shi-Wei Zhao Bo Li You-Mei Sun Pei-Xiong Zhao Jie Liu Institute of Modern Physics Chinese Academy of ScienceLanzhou 730000China University of Chinese academy of science Beijing 100049China Spallation Neutron Source science Center Dongguan 523803China China Electronics technology Group Corporation No.58 Research Institute Wuxi 214000China Beijing Microelectronics technology Institute Beijing 100084China Institute of Microelectronics Chinese Academy of SciencesBeijing 100029China Key Laboratory of science and technology on Silicon Devices Chinese Academy of SciencesBeijing 100029China

The 28 nm process has a high cost-performance ratio and has gradually become the standard for the field of radiation-hardened ***,owing to the minimum physical gate length of only 35 nm,the physical area of a standard 6T SRAM unit is approximately 0.16μm^(2),resulting in a significant enhancement of multi-cell charge-sharing ***-cell upsets(MCUs)have become the primary physical mechanism behind single-event upsets(SEUs)in advanced nanometer node *** range of ionization track effects increases with higher ion energies,and spacecraft in orbit primarily experience SEUs caused by high-energy ***,ground accelerator experiments have mainly obtained low-energy ion irradiation ***,the impact of ion energy on the SEU cross section,charge collection mechanisms,and MCU patterns and quantities in advanced nanometer devices remains *** this study,based on the experimental platform of the Heavy Ion Research Facility in Lanzhou,low-and high-energy heavy-ion beams were used to study the SEUs of 28 nm SRAM *** influence of ion energy on the charge collection processes of small-sensitive-volume devices,MCU patterns,and upset cross sections was obtained,and the applicable range of the inverse cosine law was *** findings of this study are an important guide for the accurate evaluation of SEUs in advanced nanometer devices and for the development of radiation-hardening techniques.

关键词： 28 nm static random access memory(SRAM) Energy effects Heavy ion Multiple-cell upset(MCU) Charge collection Inverse cosine law

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Online Nonstop Task Management for Storm-Based Distributed Stream Processing Engines

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Journal of Computer science & technology 2024年第1期39卷 116-138页

作者：张洲金培权谢希科王晓亮刘睿诚万寿红 School of Computer science and technology University of Science and Technology of ChinaHefei 230026China Key Laboratory of Electromagnetic Space Information Chinese Academy of SciencesHefei 230026China

Most distributed stream processing engines(DSPEs)do not support online task management and cannot adapt to time-varying data ***,some studies have proposed online task deployment algorithms to solve this ***,these approaches do not guarantee the Quality of Service(QoS)when the task deployment changes at runtime,because the task migrations caused by the change of task deployments will impose an exorbitant *** study one of the most popular DSPEs,Apache Storm,and find out that when a task needs to be migrated,Storm has to stop the resource(implemented as a process of Worker in Storm)where the task is *** will lead to the stop and restart of all tasks in the resource,resulting in the poor performance of task *** to solve this problem,in this pa-per,we propose N-Storm(Nonstop Storm),which is a task-resource decoupling DSPE.N-Storm allows tasks allocated to resources to be changed at runtime,which is implemented by a thread-level scheme for task ***,we add a local shared key/value store on each node to make resources aware of the changes in the allocation ***,each resource can manage its tasks at *** on N-Storm,we further propose Online Task Deployment(OTD).Differ-ing from traditional task deployment algorithms that deploy all tasks at once without considering the cost of task migra-tions caused by a task re-deployment,OTD can gradually adjust the current task deployment to an optimized one based on the communication cost and the runtime states of *** demonstrate that OTD can adapt to different kinds of applications including computation-and communication-intensive *** experimental results on a real DSPE cluster show that N-Storm can avoid the system stop and save up to 87%of the performance degradation time,compared with Apache Storm and other state-of-the-art *** addition,OTD can increase the average CPU usage by 51%for computation-intensive application

关键词： distributed stream processing engine(DSPE) Apache Storm online task migration online task deployment