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Wavelet Neural Network Based on NARMA-L2 Model for Prediction of Thermal Characteristics in a Feed System

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Chinese Journal of Mechanical Engineering 2011年第1期24卷 33-41页

作者： JIN chao WU Bo hu Youmin State Key Laboratory for Digital Manufacturing Equipment and Technology Huazhong University of Science and Teehnology Wuhan 430074 China School of Mechanical Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China

Research of thermal characteristics has been a key issue in the development of high-speed feed system. Most of the work carried out thus far is based on the principle of directly mapping the thermal error against the temperature of critical machine elements irrespective of the operating conditions. But recent researches show that different sets of operating parameters generated significantly different error values even though the temperature of the machine elements generated was similar. As such, it is important to develop a generic thermal error model which is capable of evaluating the positioning error induced by different operating parameters. This paper ultimately aims at the development of a comprehensive prediction model that can predict the thermal characteristics under different operating conditions （feeding speed, load and preload of ballscrew） in a feed system. A novel wavelet neural network based on feedback linearization autoregressive moving averaging （NARMA-L2） model is introduced to predict the temperature rise of sensitive points and thermal positioning errors considering the different operating conditions as the model inputs. Particle swarm optimization（PSO） algorithm is brought in as the training method. According to ISO230-2 Positioning Accuracy Measurement and ISO230-3 Thermal Effect Evaluation standards, experiments under different operating conditions were carried out on a self-made quasi high-speed feed system experimental bench huST-FS-001 by using Pt100 as temperature sensor, and the positioning errors were measured by Heidenhain linear grating scale. The experiment results show that the recommended method can be used to predict temperature rise of sensitive points and thermal positioning errors with good accuracy. The work described in this paper lays a solid foundation of thermal error prediction and compensation in a feed system based on varying operating conditions and machine tool characteristics.

关键词： wavelet neural network NARMA-L2 model particle swarm optimization thermal positioning error feed system

Generous or Selfish? Weighing Transaction Forwarding Against Malicious Attacks in Payment Channel Networks

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Journal of Computer Science & Technology 2022年第4期37卷 888-905页

作者： Yi qin qin hu Dong-Xiao Yu Xiu-Zhen Cheng School of Computer Science and Technology Shandong UniversityQingdao 266237China Department of Computer and Information Science Indiana University-Purdue University IndianapolisIndianapolis 46202U.S.A.

Scalability has long been a major challenge of cryptocurrency systems,which is mainly caused by the delay in reaching consensus when processing transactions *** an effective mitigation approach,the payment channel networks(PCNs)enable private channels among blockchain nodes to process transactions off-chain,relieving long-time waiting for the online transaction *** state-of-the-art studies of PCN focus on improving the efficiency and availability via optimizing routing,scheduling,and initial deposits,as well as preventing the system from security and privacy ***,the behavioral decision dynamics of blockchain nodes under potential malicious attacks is largely *** fill this gap,we employ the game theory to study the characteristics of channel interactions from both the micro and macro perspectives under the situation of channel depletion *** study is progressive,as we conduct the game-theoretic analysis of node behavioral characteristics from individuals to the whole population of *** analysis is complementary,since we utilize not only the classic game theory with the complete rationality assumption,but also the evolutionary game theory considering the limited rationality of players to portray the evolution of *** results of numerous simulation experiments verify the effectiveness of our analysis.

关键词： blockchain payment channel network game theory

Semi-empirical Likelihood Confidence Intervals for the Differences of Quantiles with Missing Data

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Acta Mathematica Sinica,English Series 2009年第5期25卷 845-854页

作者： Yong Song qin Jun chao ZHANG School of Mathematical Sciences Guangxi Normal University Guilin 541004 P. R. China Department of Mathematics Harbin University Harbin 150086 P. R. China

Detecting population （group） differences is useful in many applications, such as medical research. In this paper, we explore the probabilistic theory for identifying the quantile differences .between two populations. Suppose that there are two populations x and y with missing data on both of them, where x is nonparametric and y is parametric. We are interested in constructing confidence intervals on the quantile differences of x and y. Random hot deck imputation is used to fill in missing data. Semi-empirical likelihood confidence intervals on the differences are constructed.

关键词： empirical likelihood confidence interval quantile missing data hot deck imputation

Dithieno[a,e]pentalene Based Conjugated Polymers： Synthesis and Characterization

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Chinese Journal of Chemistry 2013年第11期31卷 1404-1408页

作者： chao hu qing Zhang School of Chemistry and Chemical Engineering Shanghai Jiao Tong University Shanghai 200240 China

The concept of introducing n-conjugated but anti-aromatic repeating units into conjugated polymers has been explored. The thermal stability, optical and electrochemical properties of dithieno[a,e]pentalenes （DTP） based polymers have been studied. The effect of introducing electron withdrawing repeating units into DTP based poly- mer on the physical properties of polymer has also been investigated. The new polymers showed broad absorption in visible and near-infrared region.

关键词： pentalene conjugated polymer low-bandgap polymer anti-aromatic

Homeostasis of Synapses:Expansion During Wakefulness,Contraction During Sleep

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Neuroscience Bulletin 2017年第3期33卷 359-360页

作者： chao He Zhian hu Department of Physiology Collaborative Innovation Centerfor Brain ScienceThird Military Medical UniversityChongqing 400038China

Sleep is a universal biological process occurring in almost every species of animal,and the loss of sleep has detrimental effects,especially impairments in cognition[1,2].Yet,the neuronal function of sleep is still on... 详细信息

关键词： synaptic neuronal homeostasis universal potentiation hypothesis cognition Homer shrinkage greatest

Plastic Deformation Mechanism in Double-Roller Clamping Spinning of Flanged Thin-Walled Cylinder

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Chinese Journal of Mechanical Engineering 2018年第3期31卷 76-84页

作者： Shu-qin Fan Sheng-Dun Zhao chao Chen School of Mechanical Engineering Xi’an Jiaotong University

Double?roller clamping spinning(DRCS) is a new process for forming a thin?walled cylinder with a complex surface flange. The process requires a small spinning force,and can visibly improve forming quality and production e ciency. However,the deformation mechanism of the process has not been completely understood. Therefore,both a finite element numerical simulation and experimental research on the DRCS process are carried out. The results show that both radial force and axial force dominate the forming process of DRCS. The deformation area elongates along the radial direction and bends along the axial direction under the action of the two forces. Both the outer edge and round corner of the flange show the tangential tensile stress and radial compressive stress. The middle region shows tensile tangential stress and radial stress,while the inner edge shows compressive tangential stress and radial stress. Tan?gential tensile strain causes a wall thickness reduction in the outer edge and middle regions of the flange. The large compressive thickness strain causes material accumulation and thus,an increase in the wall thickness of the round corner. Because of bending deformation,the round corner shows a large radial tensile strain in addition. The inner edge of the flange shows small radial compressive strain and tensile strain in thickness. Thus,the wall thickness on the inner edge of the flange continues to increase,although the increment is small. Furthermore,microstructure analysis and tensile test results show that the flanged thin?walled cylinder formed by DRCS has good mechanical properties. The results provide instructions for the application of the DRCS process.

关键词： Flange Double?roller clamping spinning Plastic deformation Cylinder

Mix design optimization of seawater sea sand coral aggregate concrete

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Science China(Technological Sciences) 2023年第2期66卷 378-389页

作者： SUN Li YANG ZeYu qin RenYuan WANG chao School of Civil Engineering Shenyang Jianzhu UniversityShenyang 110168China School of Environment and Civil Engineering Dongguan University of TechnologyDongguan 523808China

With the resource shortage in coastal areas,the construction of concrete structures using freshwater and river sand has brought great economic and environmental *** use of seawater,sea sand,and coral aggregates in concrete mixes has become an alternative solution for coastal and marine structures,especially for offshore structures and artificial *** this study,378 seawater,sea sand,and coral aggregate concrete(Coral-SWSSC)specimens were prepared,and their mechanical properties were investigated comprehensively through compressive tests to explore the optimized mix design at different *** showed that the mechanical properties of Coral-SWSSC were strongly correlated with the water-to-binder ratios,coastal particle gradings,and pretreatment method of coastal *** on the experimental results,mix proportion designs of CoralSWSSC were proposed for concrete from C20 to C50 grades,and the failure mechanism of Coral-SWSSC at different grades was discussed according to their respective failure *** findings of the current study provide knowledge on the optimized design of Coral-SWSSC,which can be used to promote the application of Coral-SWSSC in offshore,marine,and ocean engineering.

关键词： coral aggregate concrete sea sand seawater compressive strength failure mechanism mix proportion design

Reentry Trajectory Optimization for Hypersonic Vehicles Using Fuzzy Satisfactory Goal Programming Method

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International Journal of Automation and computing 2015年第2期12卷 171-181页

作者： chao-Fang hu Yue Xin School of Electrical Engineering and Automation Tianjin University

Constrained reentry trajectory optimization for hypersonic vehicles is a challenging job. In particular, this problem becomes more difficult when several objectives with preemptive priorities are expected for different purposes. In this paper, a fuzzy satisfactory goal programming method is proposed to solve the multi-objective reentry trajectory optimization problem. Firstly, direct collocation approach is used to discretize the reentry trajectory optimal-control problem with nonlinear constraints into nonlinear multiobjective programming problem with preemptive priorities, where attack angles and bank angles at nodes and collocation nodes are selected as control variables. Secondly, the preemptive priorities are transformed into the relaxed order of satisfactory degrees according to the principle that the objective with higher priority has higher satisfactory degree. Then the fuzzy satisfactory goal programming model is proposed. The balance between optimization and priorities is realized by regulating parameter λ, such that the satisfactory reentry trajectory can be acquired. The simulation demonstrates that the proposed method is effective for the multi-objective reentry trajectory optimization of hypersonic vehicles.

关键词： Reentry trajectory optimization direct collocation method multi-objective optimization fuzzy satisfactory method goal programmin

Current hepatitis B treatment guidelines and future research directions

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Frontiers of Medicine 2014年第2期8卷 145-157页

作者： Jonathan Skupsky Ke-qin hu Division of Gastroenterology and Hepatology University of California Irvine School of Medicine Orange CA 92868 USA

Hepatitis B virus （HBV） infection causes a tremendous clinical burden across the world with more than half a million people dying annually from HBV related disease. Significant advances have been made in HBV treatment in the past decade and several guidelines have been published by professional societies and expert panels. Although these recommendations have been valuable to help optimize HBV treatment, there is discordance in treatment criteria and many patients infected with HBV may fall outside of these recommendations. This paper systematically reviews the natural history of the disease and compares and contrasts the recommendations for initiation of treatment from the various societies. There is also discussion of special groups that require particular consideration and some of the open research questions and future research directions within the field.

关键词： chronic hepatitis B HBV treatment guidelines APASL guidelines EASL guidelines AASLD guidelines