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Defense of Massive False Data Injection Attack via Sparse Attack Points considering Uncertain Topological Changes

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Journal of Modern Power Systems and Clean Energy 2022年第6期10卷 1588-1598页

作者： Xiaoge Huang Zhijun Qin Ming Xie Hui Liu Liang Meng School of Electrical Engineering Guangxi UniversityNanningChina Guangxi Power Grid co.Ltd. China Southern Grid(CSG)GuilinChina

False data injection attack(FDIA)is a typical cyber-attack aiming at falsifying measurement data for state estimation(SE),which may incur catastrophic consequences on cyber-physical system *** this paper,we develop a deep learning based methodology for detection,localization,and data recovery of FDIA on power systems in a coherent and holistic ***,the multi-modal probability distributions of both measurements and state variables in SE due to ever-changing operating points and structural/topological changes pose great challenges in detecting and localizing *** address this challenge,we first propose an enhanced attack model to launch massive FDIA on limited access ***,we train an auto-encoder(AE)with a Bayesian change verification(BCV)classifier using N-1 contingencies to detect FDIA with unseen N-k operational ***,to avoid model collapse caused by multi-modal measurement distribution,an AE-based generative adversarial network(GAN)is derived to generate a diverse candidate set of normal measurement vectors with various operational ***,we develop a pattern match algorithm to localize and recover the falsified measurements and state variables by comparing the falsified measurement vectors with the normal measurement vectors in the candidate *** studies with IEEE benchmark systems and a modified 415-bus China Southern Grid system are provided to validate the proposed *** shows that the proposed methodology achieves an average 95%accuracy for detection,over 80%accuracy for localization of FDIA,and recovers the measurement and state variables close to their true values.

关键词： False data injection attack auto-encoder generative adversarial network state estimation cyber security

Short Stroke control with Gaussian Curve and PSO Algorithm in Plate Rolling Process

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Journal of Harbin Institute of Technology(New Series) 2013年第4期20卷 93-98页

作者： Jing-Guo Ding Li-Li Qu Xian-Lei Hu Xiang-Hua Liu State Key Laboratory of Rolling and Automation Northeastern University Shenyang Blower Ventilation co. Ltd.

The precision width control is vital for product quality and production economy in plate width control process, so short stroke control method was used in plate rolling by opening or closing edger gap so as to avoid head end necking. Head end necking on different broadening ratio was analyzed, and sections of different elongations at edger roiling was calculated; based on the law of volume constancy, the adjustment functions were described by parabolic functions. control curves were developed with three Gaussian curves by means of additional combining; SSC control curve was changed with different weights of those curves, w1 effect one-third of SSC length, w2 effect two-third of SSC length, w3 effect all three parts of SSC length. In order to adjust the amount of weights for precise quantification, PSO algorithm was used to build sufficiency function so as to obtain best rectangular degree by global optimization. Practical applications showed that the method proposed is available to improve the product rolling yields by 1.0% -2. 0% and worthy to apply to plate rolling.

关键词： plate mill short stroke control ganssian curve PSO rolling yields

Near-Iinear elastic deformation behavior of a novel Zr-Ti-Nb-Sn alloy with multi-phase microstructures ofβ,α"andα'phases

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Rare Metals 2023年第5期42卷 1670-1677页

作者： Wen Ma Hao Huang Wang Ding Shun Guo Hai-Xia Liu Xiao-Nong Cheng School of Materials Science and Engineering Jiangsu UniversityZhenjiang212013China China Grinm Group co. Ltd.Bejing100088China

In this work,a multi-phase Zr-30Ti-7Nb-4Sn alloy with large near-linear elastic deformability was prepared by the solution treatment plus pre-straining(S TP)treatment,and the underlying mechanism accountable for the near-linear elastic deformation was systematically *** was found that the Zr-30Ti-7Nb-4Sn alloy was composed ofβ,α″andα′phases,and numerous dislocations were formed in the alloy specimen after STP *** the retarding effect of high-density dislocations,the stress-induced martensitic(SIM)transformation fromβtoα″phases took place homogeneously and continuously during loading,in conjunction with the occurrence of elastic deformation ofβ,α″andα′*** the entire tensile procedure,no observable phase transformation occurred betweenα′martensite andβ***,the near-linear elastic deformation capability in STP Zr-30Ti-7Nb-4Sn alloy is mainly ascribed to the coupling actions of consecutiveβ→α″SIM transformation and intrinsic elastic deformation ofβ,α″andα′*** experimental results provide a basis for designing and developing novel multi-phase Zr-based alloys that possess large near-linear deformability.

关键词： Zr-based alloy Multi-phase Near-linear deformation behavior Martensitic transformation

Influence of recrystallization on tungsten divertor monoblock under high heat flux

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Tungsten 2022年第3期4卷 194-202页

作者： Yu-Zhong Jin Xiang Liu You-Yun Lian Jiu-Peng Song Southwestern Institute of Physics Chengdu610225China Xiamen Tungsten co.Ltd Xiamen361021China

Extremely high heat flux reaching 20 MW·m^(−2) can be foreseen for the future fusion *** high heat flux would induce recrystallization of tungsten(W)material,leading to significant strength loss of tungsten material and increment of ductility at high temperature,in particular when the temperature is much higher than its ductile-to-brittle transition temperature(DBTT).In this paper,an International Thermonuclear Experimental Reactor(ITER)-like tungsten divertor monoblock is modeled,and benchmark has been done first to get consistent results with ***,the monoblock structure has been optimized in order to get a lowest possible temperature and stress during heating and cooling phase separately compared to the baseline *** analysis of two kinds of states:stress-relieved tungsten and recrystallized tungsten using finite element method has been performed,aiming at finding out the recrystallization impact on the mechanical behavior of tungsten in divertor monoblock under cyclic high heat *** due to progressive deformation and time-independent fatigue lifetime of these two states of tungsten have been assessed and compared according to criteria The Structural Design Criteria for ITER In-vessel ***,the impact of different material recrystallization temperature on mechanical behavior has been explored under stationary heat *** result shows that after recrystallization,thermal stress of tungsten material can be released by the larger plastic deformation compared to the stress-relieved ***,it is easier for recrystallized tungsten to get damaged due to progressive deformation as well as fatigue under 20 MW·m^(−2) cyclic heat flux than stress-relieved tungsten because of its relatively lower yield strength and larger plastic strain,which would cause low-cycle strain ***,tungsten with lower recrystallization temperature distorts more seriously,and therefore,it can be predicted the cracks would

关键词： Tungsten Finite element method Divertor High heat flux Thermal stress

Adaptive beamforming and phase bias compensation for GNSS receiver

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Journal of Systems Engineering and Electronics 2015年第1期26卷 10-18页

作者： Hongwei Zhao Baowang Lian Juan Feng School of Electronics and Information Northwestern Polytechnical University Shaanxi Fiber Home communication Group co. Ltd

Adaptive antenna arrays have been used to mitigate the interference on global navigation satellite system（GNSS） receivers. The performance of interference mitigation depends on the beamforming algorithms adopted by the antenna array. However,the adaptive beamforming will change the array pattern in realtime, which has the potential to introduce phase center biases into the antenna array. For precise applications, these phase biases must be mitigated or compensated because they will bring errors in code phase and carrier phase measurements. A novel adaptive beamforming algorithm is proposed firstly, then the phase bias induced by the proposed algorithm is estimated, and finally a compensation strategy is addressed. Simulations demonstrate that the proposed beamforming algorithm suppresses effectively the strong interference and improves significantly the capturing performance of GNSS signals. Simultaneously, the bias compensation method avoids the loss of the carrier phase lock and reduces the phase measurement errors for GNSS receivers.

关键词： global navigation satellite system(GNSS) space-time adaptive processing(STAP) adaptive beamforming bias compensation

Magnetic Properties of Thermally Aged Fe-Cu Alloys with Pre-deformation

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Journal of Iron and Steel Research International 2016年第9期23卷 981-987页

作者： Yi LI Yuan-fei LI Ben XU Qiu-lin LI Guo-gang SHU Wei LIU School of Material Science and Engineering Tsinghua University Graduate School at Shenzhen Tsinghua University China Nuclear Power Engineering co. Ltd.

Magnetic properties of thermally aged Fe-Cu alloys with pre deformation have been evaluated to improve the understanding of using magnetic technology for the nondestructive evaluation （NDE） of irradiation embrittlement in reactor pressure vessel （RPV） steels. Fe-Cu alloys with and without pre-deformation were thermally aged at 500 ℃ and the changes in microstructure, mechanical properties and magnetic properties were determined. It is found that the strain-induced dislocations recover and the Cu-rich particles precipitate during the aging process, and the magnet- ic properties variation depends on the combined influence of these two factors. From the point of view of NDE, a fully tempered or annealed microstructure is favorable before RPV is put into service. These results improve the un- derstanding of magnetic property evolution in actual RPV steels and help to develop NDE theory for irradiation embrittlement.

关键词： RPV steel nondestructive evaluation magnetic property Cu-rich precipitate dislocation

Design and Performance Study of Clutch Disc Assembly of Wide-Angle, Large-Hysteresis, Multistage Damper

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Chinese Journal of Mechanical Engineering 2021年第3期34卷 345-357页

作者： Maoqing Xie Leigang Wang Yao Huang School of Materials Science and Engineering Jiangsu UniversityZhenjiang 21200China Zhejiang Tieliu Clutch co. Ltd.Yongkang 321300China

The clutch is an important component of the vehicle driveline *** of its major functions is to attenuate or eliminate the torsional vibration and noise of the driveline system caused by the *** on experiments of vibration damping under different vehicle conditions,the structure and functional principle of a clutch-driven disc assembly for a wide-angle,large-hysteresis,multistage damper is investigated in this study using an innovative combined ***,a systematic integration of key technologies,including wide-angle low-stiffness damping technology,large-hysteresis clutch technology,a novel split pre-damping structure technology,damping structure technology for component cushioning,and multistage damping structure technology,is *** results show that the total torsional angle of the wide-angle large-hysteresis,multistage damper is more than twice that of the traditional clutch *** multistage damping design allows a better consideration of various damping requirements under different vehicle conditions,which can effectively address problems of severe idle vibrations and torsional resonance that occur under idled and accelerated ***,the use of a large-hysteresis structure and wear-resistant materials not only improves the vibration damping performance,but also prolongs the product service life,consequently resulting in multi-faceted optimization and innovative products.

关键词： Clutch Noise Vibration Wide angle Low stiffness Large-hysteresis Multistage damper

The discovery of Jurassic plants in Shenzhen of Guangdong, southern China and related significance

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Chinese Science Bulletin 2014年第28期59卷 3630-3637页

作者： Yongdong Wang Xiangwu Wu Xiaoju Yang Wei Duan Liqin Li Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Shenzhen Mesozoic Culture communication co. LTD

Investigations of major marine and non-marine geologic and biotic events across the Triassic-Jurassic transition rely predominantly on detailed stratigraphic frameworks and biodiversity analyses. The alternating sequences of marine and terrestrial Triassic-Jurassic formations in Guangdong Province represent one of the most remarkable coal-bearing series in southern China. The Lower Jurassic Jinji Formation is widely distributed in Guangdong, with continuously outcropped sections and rich marine and non-marine fossil fauna. However, as little research has been conducted on fossil plant remains in the Jinji Formation, it is difficult to understand the systematics,diversity, and floral aspects of the Jurassic. Here we report on the recent collection of rich fossil plants from the Jinji Formation in the Dapeng area of Shenzhen, southern Guangdong Province. Our studies demonstrate taxonomical affiliations, preservation status, and diversity features of these plant fossils, which are marked by the close association of densely preserved, pinnae and rachis connected leaves, and the bennettitalean reproductive organs of Williamsoniella, which may represent an Early Jurassic plant community dominated by Otozamites of the *** work not only represents the first discovery of fossil plants in the Shenzhen area, but is also the first documentation of Jurassic plants in Guangdong and the Pearl River Delta regions. Research related to these plant fossils will be helpful in the correlation of the Early Mesozoic coal-bearing strata in Guangdong, and will provide a deeper understanding of variations in plant diversity of the Triassic and Jurassic transition in southern China. Additionally, it will provide terrestrial plant evidence for explorations in Jurassic palaeoecology, palaeoclimatology,and palaeogeography of southern China.

关键词：植物化石深圳地区中国南部广东省侏罗纪多样性分析动物群化石地层格架

Stock-Selection Strategies Optimization of Fund Management companies by Analytic Hierarchy Process

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Journal of Donghua University(English Edition) 2014年第4期31卷 538-544页

作者：王成兵李智 Glorious Sun School of Business and Management Donghua University Shanghai Shangyang Investment Management co . Ltd.

Securities investment fund is one of the most important institutional investors in the securities market. The quality of the management of the securities investment fund by the fund management company not only directly affects its survival and development,but also plays a decisive role in the stable operation of securities market and even the macroeconomy. As China is in rapid development of funds,scientific and effective investment strategies will be the only road for the long-term development of wellestablished fund management companies. We attempt to combine the value investment strategies with quantitative investment strategies to build a system of optimized investment strategies with the use of analytic hierarchy process so as to improve business performance of fund management companies and to foster the concept of value investment. Moreover,it possesses certain significance in enriching investment strategies for securities investment fund and promoting the healthy growth of the Chinese securities investment fund.

关键词： analytic hierarchy process securities investment fund stock-selection strategies optimization