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Structure of the Potential Vorticity of an Explosive Cyclone over the Eastern Asian Region in Late November 2013

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Journal of Ocean University of China 2022年第2期21卷 253-263页

作者： pang Huaji fu Gang LU Chungu Qingdao Engineering Technology Research Center for Meteorological Disaster Prevention Qingdao Meteorological BureauQingdao 266003China Department of Marine Meteorology Laboratories of Physical OceanographyOcean-Atmosphere Interaction and ClimateOcean University of ChinaQingdao 266100China National Science Foundation ArlingtonVA 22230USA

An explosive extratropical cyclone(EC)over the Eastern Asian region that caused two shipwrecks is analyzed using ERA-Interim reanalysis data from the European Center for Medium-Range Weather *** of the evolution of the EC reveal that the positive potential vorticity(PV)at the upper-tropospheric level displays a hook-shaped structure during the mature period of the *** PV distribution forms a vertically coherent PV structure called a PV *** vertical distribution of the PV can induce and strengthen cyclonic circulation from the lower-to upper-levels of troposphere,which is an important deepening mechanism of explosive *** PV tower occurs approximately ten hours prior to the development of surface occlusion in the *** evolution of surface fronts closely follows the development of the horizontal upper-tropospheric *** tandem development is largely attributed to the ability of the positive upper-tropospheric PV and the PV tower to induce cyclonic circulation *** kinematic wrap-up process of cyclonic circulation also accelerates the formation of warm occlusion.A conceptual model of the distributions of positive PV and potential temperature combining the perspectives of dynamic tropopause folding,PV tower,and atmospheric stability,including westward tilting and baroclinicity,is *** model can illustrate the explosive deepening mechanism of *** regions of convective instability and rainfall determined by this model are consistent with those identified from the actual observation.

关键词： extratropical cyclone rapidly deepening mechanism potential vorticity front evolution coupling of upper-and low-troposphere

Analysis of Stealthy False Data Injection Attacks Against Networked Control Systems:Three Case Studies

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Journal of Systems Science & Complexity 2023年第4期36卷 1407-1422页

作者： pang Zhonghua fu Yuan GUO Haibin SUN Jian Key Laboratory of Fieldbus Technology and Automation of Beijing North China University of TechnologyBeijing 100144China National Key Laboratory of Autonomous Intelligent Unmanned Systems School of AutomationBeijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Chongqing Innovation Center Chongqing 401120China

This paper mainly investigates the security problem of a networked control system based on a Kalman filter.A false data injection attack scheme is proposed to only tamper the measurement output,and its stealthiness and effects on system performance are analyzed under three cases of system knowledge held by an attacker and a ***,it is derived that the proposed attack scheme is stealthy for a residual-based detector when the attacker and the defender hold the same accurate system ***,it is proven that the proposed attack scheme is still stealthy even if the defender actively modifies the Kalman filter gain so as to make it different from that of the ***,the stealthiness condition of the proposed attack scheme based on an inaccurate model is ***,for each case,the instability conditions of the closed-loop system under attack are ***,simulation results are provided to test the proposed attack scheme.

关键词： False data injection attack networked control systems(NCSs) stability stealthiness

A Load Balancing Model Based on Cloud Partitioning for the Public Cloud

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Tsinghua Science and Technology 2013年第1期18卷 34-39页

作者： Gaochao Xu Junjie pang Xiaodong fu College of Computer Science and Technology Jilin University College of Software Jilin University

Load balancing in the cloud computing environment has an important impact on the performance. Good load balancing makes cloud computing more efficient and improves user satisfaction. This article introduces a better load balance model for the public cloud based on the cloud partitioning concept with a switch mechanism to choose different strategies for different situations. The algorithm applies the game theory to the load balancing strategy to improve the efficiency in the public cloud environment.

关键词： load balancing model public cloud cloud partition game theory

Structure Analyses of the Explosive Extratropical Cyclone:A Case Study over the Northwestern Pacific in March 2007

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Journal of Ocean University of China 2017年第6期16卷 933-944页

作者： WANG Shuai fu Gang pang Huaji College of Oceanic and Atmospheric Sciences Ocean University of China Qingdao 266100 P. R. China Department of Physics Imperial College London London SW7 2AZ UK Qingdao Meteorological Bureau Qingdao 266003 P. R. China

The synoptic situation and mesoscale structure of an explosive extratropical cyclone over the Northwestern Pacific in March 2007 are investigated through weather station observations and data reanalysis. The cyclone is located beneath the poleward side of the exit of a 200 hPa jet, which is a strong divergent region aloft. At mid-level, the cyclone lies on the downstream side of a well-developed trough, where a strong ascending motion frequently occurs. Cross-section analyses with weather station data show that the cyclone has a warm and moist core. A ‘nose' of the cold front, which is characterized by a low-level protruding structure in the equivalent potential temperature field, forms when the cyclone moves offshore. This ‘nose' structure is hypothesized to have been caused by the heating effect of the Kuroshio Current. Two low-level jet streams are also identified on the western and eastern sides of the cold front. The western jet conveys cold and dry air at 800–900 hPa. The wind in the northern part is northeasterly, and the wind in the southern part is northwesterly. By contrast, the eastern jet carries warm and moist air into the cyclone system, ascending northward from 900 hPa to 600–700 hPa. The southern part is dominated by the southerly wind, and the wind in the northern part is southwesterly. The eastern and western jets significantly increase the air temperature and moisture contrast in the vicinity of the cold front. This increase could play an important role in improving the rapid cyclogenesis process.

关键词： explosive extratropical cyclone meteorological bomb rapid cyclogenesis mesoscale structure northwestern Pacific

The Existence of a Class of Balanced Multi-output Rotation Symmetric Boolean functions

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Chinese Journal of Electronics 2018年第5期27卷 995-1001页

作者： DU Jiao fu Shaojing QU Longjiang LI Chao pang Shanqi College of Mathematics and Information Science Henan Normal University Henan Engineering Laboratory for Big Data Statistical Analysis and Optimal Control Henan Normal University College of Computer Science National University of Defense Technology College of Liberal Arts and Science National University of Defense Technology

A new characterization of balanced rotation symmetric（n, m）-functions is presented. Based on the characterization, the nonexistence of balanced rotation symmetric（p;, m）-functions is determined, where p is an odd prime and m ≥ 2. And there exist balanced rotation symmetric（2;, m）-functions for 2 ≤ m ≤ 2;-r. With the help of these results, we also prove that there exist rotation symmetric resilient（2;, m）-functions for 2 ≤ m ≤ 2;-r-1.

关键词： Cryptography Rotation symmetric Orbit matrix Correlation immune Resilient functions

A combined virtual impactor and field-effect transistor microsystem for particulate matter separation and detection

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Nanotechnology and Precision Engineering 2021年第1期4卷 17-25页

作者： Yanna Li Muqing fu Wei pang Ye Chang Xuexin Duan State Key Laboratory of Precision Measuring Technology and Instruments Tianjin UniversityTianjin 300072China School of Precision Instrument and Opto-Electronics Engineering Tianjin UniversityTianjin 300072China

Ambient suspended particulate matter(PM)(primarily with particle diameter 2.5m or less,i.e.,PM2.5)can adversely affect ecosystems and human ***,optical particle sensors based on light scattering dominate the portable PM sensing ***,the light scattering method has poor adaptability to different-sized PM and adverse environmental ***,we design and develop a portable PM sensing microsystem that consists of a micromachined virtual impactor(VI)for particle separation,a thermophoretic deposition chip for particle collection,and an extended-gate field-effect transistor(FET)for particle *** system can realize on-site separation,collection,and analysis of aerosol particles without being influenced by environmental *** this study,the design of the VI is thoroughly analyzed by numerical simulation,and mixtures of different-sized silicon dioxide(SiO2)particles are used in an experimental verification of the performance of the VI and *** the low cost and compact design of the whole system,the proposed PM analysis microsystem has potential for PM detection under a wide range of conditions,such as heavily polluted industrial environments and for point-of-need outdoor and indoor air quality monitoring.

关键词： Particulate matter Microsystem Virtual impactor 50%cutoff diameter Field-effect transistor

Flow hydrogen absorption of LaFe_(10.9)Co_(0.8)Si_(1.3) compound under constant low hydrogen gas pressure

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Rare Metals 2018年第3期37卷 243-248页

作者： Bin fu Jun He Jie Han Jie Hu Li-Wei pang Tianjin Key Laboratory for Photoelectric Materials & Devices School of Materials Science and EngineeringTianjin University of Technology Division of functional Material Research Central Iron and Steel Research Institute College of Science Tianjin University of Technology School of Materials Science and Engineering Shijiazhuang Tiedao University

The hydrogen absorption of the LaFe（10.9）-Co（0.8）Si（1.3） compound under constant 1.01 × 10-5 Pa H2 gas in a flow hydrogen atmosphere was studied. The effects of hydrogen absorption on structure, Curie temperature, phase transition and magnetic property were investigated by X-ray diffraction（XRD）, differential scanning calorimeter（DSC） and superconducting quantum interference device,respectively. The hydrides of LaFe（10.9）Co（0.8）Si（1.3） crystallize into NaZn（13）-type structural phase after hydrogen absorption at temperature from 548 to 623 K. Lower hydrogen absorption temperature is of no advantage for pure 1：13 phase formation in a flow H2 atmosphere. The Curie temperature（TC） of LaFe（10.9）Co（0.8）Si（1.3） compound increases by70 K or more after hydrogen absorption. For LaFe（10.9）-Co（0.8）Si（1.3）H（1.8） compound, the maximum magnetic entropy change and the relative cooling power under a magnetic field change of 0-2 T are 6.1 J·kg^-1·K^-1 and 170 J·kg^-1,respectively. Large refrigerant capacity, low hysteresis loss and wide temperature span of magnetic entropy change peak make it a competitive practical candidate for magnetic refrigerant.

关键词： La(FexSi1-x)13 compounds Magnetic refrigerant Hydrogen absorption Magnetic entropy change

Growth and Distribution of Amphioctopus fangsiao(d'Orbigny, 1839–1841) in Haizhou Bay, Yellow Sea

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Journal of Ocean University of China 2020年第5期19卷 1125-1132页

作者： pang Yumeng TIAN Yongjun fu Caihong REN Yiping WAN Rong Fisheries College Ocean University of ChinaQingdao 266003China Frontiers Science Center for Deep Ocean Multispheres and Earth System(FDOMES) Ocean University of ChinaQingdao 266100China Laboratory for Marine Fisheries Science and Food Production Processes Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China Fisheries and Oceans Canada Pacific Biological StationNanaimoBritish Columbia V9T 6N7Canada College of Marine Sciences Shanghai Ocean UniversityShanghai 201306China

Octopus fisheries have prospered in many areas of the world ocean over the last six decades. Despite degradation and overexploitation of Chinese coastal ecosystems, octopus has become a stable Chinese domestic fishery species. Among the octopus species in the Bohai and Yellow, East and South China Seas, Amphioctopus fangsiao(d'Orbigny [in Férussac & d'Orbigny], 1839–1841) plays an increasingly important role both economically and ecologically. However, no systematic research has been conducted on its biology and population dynamics in the China Seas. In this study, we characterized the growth and distribution of A. fangsiao in Haizhou Bay, Yellow Sea based on four years of trawl survey data. As the results, A. fangsiao is characterized by allometric growth and an overall sex ratio of 0.97 with a slight male bias. Small octopus can be observed through a whole year, suggesting that A. fangsiao may have an extended or continuous spawning season. A. fangsiao may migrate short distances along with seasonal changes and coastal currents, considering they overwinter in the offshore water and spawn in the inshore water. In addition to fishing pressure, annual variations in the population structure and biomass appeared to be influenced by ambient water temperature. These results provide basic biological information for a better understanding of the population dynamics and the ecological importance of A. fangsiao.

关键词： Amphioctopus fangsiao cephalopod Haizhou Bay growth spatial distribution

Probability Distribution Characteristics of Strong Nonlinear Waves Under Typhoon Conditions in the Northern South China Sea

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Journal of Ocean University of China 2024年第3期23卷 583-593页

作者： GONG Yijie XIE Botao fu Dianfu WANG Zhifeng pang Liang College of Engineering Ocean University of ChinaQingdao 266100China CNOOC Research Institute Ltd. Beijing 100028China

The generation and propagation mechanism of strong nonlinear waves in the South China Sea is an essential research area. In this study, the third-generation wave model WAVEWATCH Ⅲ is employed to simulate wave fields under extreme sea states. The model, integrating the ST6 source term, is validated against observed data, demonstrating its credibility. The spatial distribution of the occurrence probability of strong nonlinear waves during typhoons is shown, and the waves in the straits and the northeastern part of the South China Sea show strong nonlinear characteristics. The high-order spectral model HOS-ocean is employed to simulate the random wave surface series beneath five different platform areas. The waves during the typhoon exhibit strong nonlinear characteristics, and freak waves exist. The space-varying probability model is established to describe the short-term probability distribution of nonlinear wave series. The exceedance probability distributions of the wave surface beneath different platform areas are compared and analyzed. The results show that with an increase in the platform area, the probability of a strong nonlinear wave beneath the platform increases.

关键词： strong nonlinear wave typhoon wave series probability distribution model exceedance probability