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PARAMETRIC IDENTIFICATION AND SENSITIVITY ANALYSIS FOR AUTONOMOUS UNDERWATER VEHICLES IN DIVING PLANE

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Journal of Hydrodynamics 2012年第5期24卷 744-751页

作者： XU Feng ZOU Zao-jian YIN jian-chuan cao jian School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240China School of Naval Architecture Ocean and Civil Engineering and State Key Laboratory of Ocean EngineeringShanghai Jiao Tong University Shanghai 200240 China College of Shipbuilding Engineering Harbin Engineering University Harbin 150001 China

The inherent strongly nonlinear and coupling performance of the Autonomous Underwater Vehicles （AUV）, maneuvering motion in the diving plane determines its difficulty in parametric identification. The motion parameters in diving plane are obtained by executing the Zigzag-like motion based on a mathematical model of maneuvering motion. A separate identification method is put forward for parametric identification by investigating the motion equations. Support vector machine is proposed to estimate the hydrodynamic derivatives by analyzing the data of surge, heave and pitch motions. Compared with the standard coefficients, the identified parameters show the validation of the proposed identification method. Sensitivity analysis based on numerical simulation demonstrates that poor sensitive derivative gives bad estimation results. Finally the motion simulation is implemented based on the dominant sensitive derivatives to verify the reconstructed model.

关键词： parametric identification Autonomous Underwater Vehicles (AUVs) support vector machine sensitivity analysis

Analysis of hot leg natural circulation under station blackout severe accident

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Nuclear Science and Techniques 2007年第2期18卷 123-128页

作者： DENG jian cao Xuewu School of Nuclear Science and Engineering Shanghai Jiaotong University Shanghai 200240 China

Under severe accidents, natural circulation flows are important to influence the accident progression and result in a pressurized water reactor (PWR). In a station blackout accident with no recovery of steam generator (SG) auxiliary feedwater (TMLB' severe accident scenario), the hot leg countercurrent natural circulation flow is analyzed by using a severe-accident code, to better understand its potential impacts on the creep-rupture timing among the surge line, the hot leg, and SG tubes. The results show that the natural circulation may delay the failure time of the hot leg. The recirculation ratio and the hot mixing factor are also calculated and discussed.

关键词：压水堆全场断电严重事故热管段自然循环

Distinct response of Northern Hemisphere land monsoon precipitation to transient and stablized warming scenarios

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Advances in Climate Change Research 2020年第3期11卷 161-171页

作者： cao jian ZHAO Hai-Kun Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science and TechnologyNanjing210044China Earth System Modeling Center Nanjing University of Information Science and TechnologyNanjing210044China

To better understand the climate response under stabilized,overshoot,and transient global warming,four types of ensemble experiments on 1.5℃/2℃ global warming scenarios(i.e.,stabilized 1.5℃,1.5℃ overshoot,stabilized 2℃,and transient 2℃)are elaborately designed using the Nanjing University Information Science and Technology Earth System Model(NESM).Compared with the modern climate(1985–2014),the projected surface air temperature(SAT)change is characterized by a robust‘Northern Hemisphere(NH)-warmer than-Southern Hemisphere(SH)’and‘land-warmer than-ocean’*** projected precipitation change exhibits‘NH-wetter than-SH’pattern in the *** the response of SAT and precipitation climatology show similar pattern between stabilized and overshoot scenarios,some significant differences are still *** projected change in the Northern Hemisphere land monsoon precipitation(NHLMP)is 30% larger in the transient 2℃ experiment compared with that in the stabilized 2℃ *** more vigorous NHLMP in the transient global warming scenario is mainly due to the enhanced land-sea thermal contrast and interhemispheric temperature *** enlarged land-sea thermal contrast increases the surface pressure gradient between the NH continents and its adjacent oceans,thus enhancing the NH monsoon circulation and moisture *** enhanced interhemispheric temperature difference shifts the Hadley circulation and intertropical convergence zone northward,leading to the enhanced moisture convergence and the shifts of tropical rain band over the NH monsoon *** result highlights that climate responses may depend on different warming trajectories and,which could facilitate the strategic planning of governments.

关键词： 1.5℃/2℃global warming Monsoon precipitation NESM model Transient global warming Stabilized global warming

PARAMETRIC IDENTIFICATION OF PARALLEL MANIPULATOR WITH REDUNDANCY DRIVEN BY PNEUMATIC MUSCLES

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Chinese Journal of Mechanical Engineering 2008年第1期21卷 66-71页

作者： ZHU Xiaocong TAO Guoliang cao jian State Key Laboratory of Fluid Power Transmission and Control Zhejiang University Hangzhou 310027 China

A new parameter estimation algorithm is proposed for parametric identification of a parallel manipulator driven by pneumatic muscles with redundancy. Due to the special physical properties of the parallel manipulator studied, the regression model for parametric identification is characterized by multieollinearity, which will result in unreliable and inaccurate parameter estimations with large eovarianee if the conventional parameter estimation algorithm based on single error minimizing criterion is used. To improve the quality of parameter estimation and achieve high precise posture trajectory tracking control of the parallel manipulator, a new parameter estimation algorithm based on composite error minimizing criterion is developed in need of theoretical contractive forces of pneumatic muscles. The experimental results indicate that the proposed algorithm integrated with adaptive robust control could provide reliable parametric identification and greatly enhance the control accuracy in the trajectory tracking control of the parallel manipulator, and that the variation of known theoretical contractive forces of pneumatic muscles has slight influence on the control performance.

关键词： Pneumatic muscle Parallel manipulator Redundancy Parameter estimation

Hydrogen and steam distribution following a small-break LOCA in large dry containment

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Nuclear Science and Techniques 2007年第3期18卷 181-185页

作者： DENG jian cao Xuewu School of Nuclear Science and Engineering Shanghai Jiaotong University Shanghai 200240 China

The hydrogen deflagration is one of the major risk contributors to threaten the integrity of the containment in a nuclear power plant, and hydrogen control in the case of severe accidents is required by nuclear regulations. Based on the large dry containment model developed with the integral severe-accident analysis tool, a small-break loss-of-coolant-accident (LOCA) without HPI, LPI, AFW and containment sprays, leading to the core degradation and large hydrogen generation, is calculated. Hydrogen and steam distribution in containment compartments is investi- gated. The analysis results show that significant hydrogen deflagration risk exits in the reactor coolant pump (RCP) compartment and the cavity during the early period, if no actions are taken to mitigate the effects of hydrogen accu- mulation.

关键词：氢蒸发严重事故氢分布小破口事故

Effects of source facies and maturity on individual carbon isotopic compositions of oil

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Geoscience Frontiers 2024年第5期15卷 210-221页

作者： Jingkun Zhang jian cao Baoli Xiang State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China MOE Key Laboratory of Surficial Geochemistry School of Earth Sciences and EngineeringNanjing UniversityNanjing 210023China Research Institute of Experiment and Testing PetroChina Xinjiang Oilfield CompanyKaramayXinjiang 834000China

Carbon isotopes have been used extensively in tracing the sources of ***,primary source facies and secondary alteration controls on oil isotopic compositions have not been well resolved,resulting in application uncertainties.A case study was undertaken for an alkaline lacustrine oil system in a lower Permian formation in the Junggar Basin,NW *** indicate that increasing maturity causes the carbon isotopic composition to become heavier for only short–middle-chain compounds,whereas source facies-related carbon assimilation controls the compositions of short-,middle-,and long-chain *** particular,light-carbon assimilation during organic-matter degradation makes the isotopic composition lighter,whereas heavy carbon from the water mass makes it ***,oils in this study area were divided into Type U and Type N oils based on individual compound carbon isotopic compositions,reflecting the difference in source facies in a highly saline and reducing stratified water *** results provide a better understanding of the controls on carbon isotopes in oil in sedimentary basins,reducing the uncertainty in oil–source correlation and addressing the origin of oil.

关键词： Carbon assimilation Water stratification Carbon isotopes Alkaline lacustrine Junggar Basin

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Finite NPDM-groups

Acta Mathematica Sinica,English Series 2021年第2期37卷 306-314页

作者： jian Ji cao Xiu Yun GUO School of Applied Mathematics Shanxi University of Finance and EconomicsTaiyuan 030006P.R.China Department of Mathematics Shanghai UniversityShanghai 200444P.R.China

In this paper the classification is given for finite groups in which the normalizer of every non-normal cyclic subgroup of order divided by the minimal prime of |G| is a maximal subgroup.

关键词： Normalizer cyclic subgroup maximal subgroup

Joining SiO_(2)based ceramics:recent progress and perspectives

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Journal of Materials Science & Technology 2022年第13期108卷 110-124页

作者： Haohan Wang Jinghuang Lin Junlei Qi jian cao State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

Nowadays,SiO_(2)based material is one of the widest used materials in optical,microelectromechanical system,aerospace and some other *** practical application,SiO_(2)based materials are required to be joined with themselves or other heterogeneous materials to assemble products with various *** the joining quality directly affects the mechanical performances and functional properties of assembled *** many researchers studied different joining technologies,explored the microstructure of joining interface and tested after-joining properties,a review that summarizes the recent cutting-edge researches and development tendency of joining technologies for SiO_(2)based ceramics is still ***,according to different applications and requirements,this review summarizes the widely used joining technologies and discusses corresponding joining mechanisms,current research progress and suitable *** to the wide applications in specific industry,laser welding,anodic bonding and wafer bonding are discussed in ***,brazing,the widest used method in SiO_(2)joining,has been elaborated deeply in its wetting mechanism,residual stress control,interfacial microstructure and mechanical performance *** the end,this review proposed the future development trends of SiO_(2)ceramics joining,aiming at offering a full-view of potential improvements in SiO_(2)ceramic joining technologies.

关键词： SiO_(2)joining current research progress brazing future development trend

Heat Transfer Characteristics of the Microfluidic Biomimetic Chameleon Skin with Active Thermal Camouflage

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Journal of Bionic Engineering 2023年第2期20卷 722-733页

作者： Lujia Li Huanhuan Li jian cao Songjing Li Department of Fluid Control and Automation Harbin Institute of TechnologyHarbin150001China

Natural organisms have different techniques to avoid enemies,such as chameleon skin with innate camouflage ability to change with the surrounding *** by this,a microfluidic biomimetic chameleon skin based on infrared(IR)information processing is proposed for active thermal camouflage in a dynamic infrared *** circulation in microcavities distributed under the skin is controlled by a thermal camouflage *** structure and working principle of the biomimetic skin are introduced,and the thermal camouflage system is established and tested to explore the heat transfer characteristics between the skin and the *** mechanism of collecting the background infrared information and regulating the skin temperature through the control signal generated by the infrared information processing system is ***,the dynamic thermal response of the skin is tested when transitioning between different temperature backgrounds,modeling the ambient temperature of the sand,woodland and lakes where chameleons *** performance of the skin is evaluated by measuring the camouflage responding time of the skin to an external heat *** results show that the chameleon biomimetic skin is naturally transitioned and matched by infrared information processing and *** limitation that the conventional thermal camouflage technology cannot adapt to the dynamic combat environment is overcome and the weaknesses of a small camouflage band range and a single form of camouflage are resolved in this study,thus effectively improving the target’s survivability in combat.

关键词： Biomimetic skin Thermal camouflage Microfluidics Infrared Chameleon