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Sensitivity Analysis of the Effect of Speed and Inclination Angle on Water-Entry Slamming Pressure of the Bow

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China Ocean Engineering 2020年第3期34卷 432-440页

作者： ZHANG Jian YOU Yun YAO Zhi huo fa-li Jiangsu University of Science and Technology Zhenjiang 212003China Shanghai Merchant Ship Design&Research Institute Shanghai 201203China

In this paper,a method about the water-entry slamming of a two-dimensional(2D)bow structure has been proposed based on the experimental and simulation *** to this method,the sensitivity analysis has been carried out about the effect of speed and inclination angle on the slamming pressure of the ***,a 2D ship bow experimental model was performed to obtain the slamming pressure distribution at different measuring points under different ***,numerical simulation for the water-entry slamming of this experimental model was conducted to obtain the pressure distribution on the experimental model under different working ***,the experimental results were compared with the numerical simulation results to evaluate the effect of speed and inclination angle on the slamming pressure of the *** results show that the slamming pressure is more sensitive to speed variation within the low-speed *** effect of inclination angle on the slamming pressure is more obvious in the small angle *** the inclination angle is larger than 45°,the effect is limited.

关键词： model test numerical simulation water-entry slamming rigid body

Impact Analysis of Air Gap Motion with Respect to Parameters of Mooring System for Floating Platform

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China Ocean Engineering 2017年第2期31卷 141-150页

作者： SHEN Zhong-xiang huo fa-li NIE Yan liU Yin-dong Transportation Equipments and Ocean Engineering College Dalian Maritime University Dalian 116026 China School of Naval Architecture and Offshore Engineering Jiangsu University of Science and Technology Zhenjiang 212003 China Grenland Group (China) Ltd. Shanghai 201206 China

In this paper, the impact analysis of air gap concerning the parameters of mooring system for the semi-submersible platform is conducted. It is challenging to simulate the wave, current and wind loads of a platform based on a model test simultaneously. Furthermore, the dynamic equivalence between the truncated and full-depth mooring system is still a tuff work. However, the wind and current loads can be tested accurately in wind tunnel model. Furthermore, the wave can be simulated accurately in wave tank test. The full-scale mooring system and the all environment loads can be simulated accurately by using the numerical model based on the model tests simultaneously. In this paper, the air gap response of a floating platform is calculated based on the results of tunnel test and wave tank. Meanwhile, full-scale mooring system, the wind, wave and current load can be considered simultaneously. In addition, a numerical model of the platform is tuned and validated by ANSYS AQWA according to the model test results. With the support of the tuned numerical model, seventeen simulation cases about the presented platform are considered to study the wave, wind, and current loads simultaneously. Then, the impact analysis studies of air gap motion regarding the length, elasticity, and type of the mooring line are performed in the time domain under the beam wave, head wave, and oblique wave conditions.

关键词： mooring system air gap floating platform

Strength Analysis on Brace Structure for Semi-Submersible in Consideration of Wave Slamming

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China Ocean Engineering 2018年第5期32卷 536-545页

作者： huo fa-li YAO Zhi ZHANG Jian WANG Jun-wei DONG Bin School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Grenland Group(China)Ltd. Shanghai 201206China

Slamming on bracings of column stabilized units shall be considered as a possible limiting criterion under transit condition based on the requirements in DNV-OS-C103. However, the wave slamming loads under survival condition were ignored for the strength analysis of the brace structures in many semi-submersible projects. In this paper, a method of strength analysis of brace structure is proposed based on the reconstruction and extrapolation of numerical model. The full-scale mooring system, the wind, wave and current loads can be considered simultaneously. Firstly,the model tests of the semi-submersible platform in wind tunnel and wave tanker have been carried out. Secondly,the numerical models of the platform are reconstructed and extrapolated based on the results of model tests. Then, a nonlinear numerical analysis has been conducted to study the wave slamming load on brace in semi-submersible platform through the reconstructed and extrapolated numerical model. For the randomness of wave load, ten subcases under each condition have been carried out. The value of the 90% Gumble distribution values of the ten subcases are used. Finally, the strength on brace structure has been analyzed considering the wave slamming. The wave slamming loads have been compared between the survival condition and transit condition with the method. The results indicate that wave slamming under survival condition is more critical than that under transit ***, the wave slamming is significant to the structural strength of the brace. It should be overall considered in the strength analysis of the brace structure.

关键词： semi-submersible platform wave slamming brace structure structural strength

Robust Interval State Estimation for Distribution Systems Considering Pseudo-measurement Interval Prediction

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Journal of Modern Power Systems and Clean Energy 2024年第1期12卷 179-188页

作者： Xu Zhang Wei Yan Meiqing huo Hui li the School of Electrical Engineering Chongqing UniversityChongqing 400044China

Interval state estimation(ISE)can estimate state intervals of power systems according to confidence intervals of predicted pseudo-measurements,thereby analyzing the impact of uncertain pseudo-measurements on ***,predicted pseudo-measurements have prediction errors,and their confidence intervals do not necessarily contain the truth values,leading to estimation biases of the *** solve this problem,this paper proposes a pseudo-measurement interval prediction framework based on the Gaussian process regression(GPR)model,thereby improving the prediction accuracy of pseudo-measurement confidence ***,a weight assignment strategy for improving the robustness of weighted least squares(WLS)ISE is *** strategy quantifies the deviation between the pseudo-measurement intervals and their estimated intervals and assigns smaller weights to the pseudo-measurement intervals with larger deviations,thereby improving the estimation accuracy and robustness of the *** paper adopts the data from the supervisory control and data acquisition(SCADA)system of the New York Independent System Operator(NYISO).It verifies the advantages of the GPR method for pseudo-measurement interval prediction by comparing it with the quantile regression and neural network *** addition,this paper demonstrates the effectiveness of the proposed weight assignment strategy through the IEEE 14-bus ***,the differences in the estimation accuracy and the bad data identification between the robust interval state estimation and deterministic state estimation are discussed.

关键词： Interval state estimation interval analysis pseudo-measurement Gaussian process regression(GPR)

Indian monsoon drove the dispersal of the thoracica group of Scytodes spitting spiders

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Zoological Research 2024年第1期45卷 152-159页

作者： Yu-fa Luo Shu-Qiang li School of life and Environmental Sciences Shaoxing UniversityShaoxingZhejiang 312000China Key Laboratory of Zoological Systematics and Evolution Institute of ZoologyChinese Academy of SciencesBeijing 100101China Southeast Asia Biodiversity Research Institute Chinese Academy of SciencesYezinNay Pyi Taw 05282Myanmar

We examined the global biogeography of the Scytodes thoracica group of spitting spiders based on 23 years of sampling at the species level(61 species in the thoracica group and 84 species of Scytodes)using DNA data from six *** results indicated that the thoracica group initially dispersed from Southeast Asia to East Africa between 46.5 and 33.0 million years ago,and dispersal events intensified between Southeast/South Asia and East/South Africa from the early to late *** timing of these events indicates that Asian-African faunal exchange of the thoracica group was driven by the Indian monsoon,and the pattern of dispersal suggests that colonialization took root when the Indian monsoon shifted from a North-South direction to an East-West direction from the middle Eocene.

关键词： Geological event Climate change Ballooning organism faunal exchange Species distribution

Considering individual game behavior and time delay in the multi-channel rumor propagation model

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Communications in Theoretical Physics 2024年第7期76卷 9-29页

作者： Yafang Dong liang'an huo Xiaoxiao Xie Ming li Business School University of Shanghai for Science and TechnologyShanghai 200093China School of Intelligent Emergency Management University of Shanghai for Science and TechnologyShanghai 200093China

The rapid development of the Internet has accelerated the spread of rumors,posing challenges to social cohesion and *** address this,a multi-channel rumor propagation model incorporating individual game behavior and time delay is *** depicts individuals strategically choosing propagation channels in the rumor spread process,capturing real-world intricacies more ***,the model allowing spreaders to choose between text and video information base *** adoption hinges on benefits versus costs,with payoffs dictating strategy and the propagation process determining an individual's *** theoretical analysis of the model,the propagation threshold and equilibrium points are *** the stability of the model is further demonstrated based on Routh-Hurwitz judgment and Descartes'Rule of *** simulations are conducted to verify the correctness of the theoretical results and the sensitivity of the model to key *** outcomes reveal that increasing the propagation cost of spreaders can significantly curb the spread of *** contrast to the classical ISR model,rumors spread faster and more widely in the improved multi-channel rumor propagation model in this paper,which is a feature more aligned with real-world ***,the validity and predictive ability of the model are verified by using real rumor propagation data sets,indicating that the improved multi-channel rumor propagation model has good practical application and predictive value.

关键词： multi-channel rumor propagation time delay game behavior

水深对半潜式平台水动力性能及波浪载荷的影响

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船舶工程 2014年第6期36卷 100-104页

作者：霍发力上海交通大学船舶海洋与建筑工程学院上海200030 戈朗(上海)海事技术咨询有限公司上海201206

根据有条件的建模方法(CMA)和一次逆可靠度方法(IFORM),运用Matlab编程计算确定百年一遇波高-周期的等概率曲线,设计了一组百年一遇波浪海况。根据Morison方程与绕射理论计算海洋平台波浪载荷的各自特点,采用Morison方程和绕射理论相结... 详细信息

根据有条件的建模方法(CMA)和一次逆可靠度方法(IFORM),运用Matlab编程计算确定百年一遇波高-周期的等概率曲线,设计了一组百年一遇波浪海况。根据Morison方程与绕射理论计算海洋平台波浪载荷的各自特点,采用Morison方程和绕射理论相结合的方法,运用DNV研发的SESAM程序,就水深对半潜式海洋平台水动力性能和波浪载荷的影响进行了分析。

关键词：半潜平台水动力性能气隙二阶漂移力

Effect of droplet characteristics on liquid-phase distribution in spray zone of internal mixing air-mist nozzle

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China Foundry 2024年第2期21卷 185-196页

作者： Wei-li Wu Chang-gui Cheng Yang li Shi-fa Wei De-li Chen The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China Technology Center Fushun Special Steel Co.Ltd.Fushun 113001LiaoningChina

In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab *** order to study the behavior of atomized droplets after reaching the slab surface and to optimize the spray cooling effect,the influence of droplet diameter and droplet velocity on the migration behavior of droplets in the secondary cooling zone was analyzed by FLUENT *** show that the droplets in the spray zone and on the slab surface are mainly concentrated in the center,thus,the liquid volume fraction in the center is higher than that of either *** the droplet diameter increases,the region of high liquid volume fraction on the slab surface becomes wider,and the liquid phase distribution in the slab width direction becomes *** increasing the droplet velocity at the nozzle exit has little effect on droplet diffusion in the spray zone,the distribution becomes more uneven due to more liquid reaches the slab surface per unit time.A prediction formula of the maximum water flow rate on the slab surface for specific droplet characteristics was proposed based on dimensionless analysis and validated by simulated data.A nozzle spacing of 210 mm was recommended under the working conditions in this study,which ensures effective coverage of the spray water over the slab surface and enhances the distribution uniformity of water flow rate in the transverse direction.

关键词： continuous casting secondary cooling zone internal mixing air-mist nozzle droplet characteristics liquid phase distribution water flow rate

Energy-efficient computation offloading assisted by RIS-based UAV

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The Journal of China Universities of Posts and Telecommunications 2024年第1期31卷 37-48页

作者： li linpei Zhao Chuan Su Yu huo Jiahao Huang Yao li Haojin School of Intelligence Science and Technology University of Science and Technology BeijingBeijing 100083China Institute of Artificial Intelligence University of Science and Technology BeijingBeijing 100083China Shunde Innovation School University of Science and Technology BeijingFoshan 528399China School of Computer and Communication Engineering University of Science and Technology BeijingBeijing 100083China Research Department of 5G and Drone China Mobile(Chengdu)Institute of Research and DevelopmentChengdu 610200China College of Communication Engineering Chengdu University of Information TechnologyChengdu 610225China Research and Development Center Sony(China)LimitedBeijing 100027China

The new applications surge with the rapid evolution of the mobile *** explosive growth of the data traffic aroused by the new applications has posed great computing pressure on the local *** is essential to innovate the computation offloading methods to alleviate the local computing burden and improve the offloading *** edge computing(MEC)assisted by reflecting intelligent surfaces(RIS)-based unmanned aerial vehicle(UAV)is a promising method to assist the users in executing the computation tasks in proximity at low *** this paper,we propose an energy-efficient MEC system assisted by RIS-based UAV,where the UAV with RIS mounted relays the computation tasks to the MEC *** energy efficiency maximization problem is formulated by jointly optimizing the UAV's trajectory,the transmission power of all users,and the phase shifts of the reflecting elements placed on the *** that the optimization problem is non-convex,we propose a deep deterministic policy gradient(DDPG)-based *** combining the DDPG algorithm with the energy efficiency maximization problem,the optimization problem can be ***,the numerical results are illustrated to show the performance of the system and the superiority compared with the benchmark schemes.

关键词： mobile edge computing unmanned aerial vehicle reflecting intelligent surface