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Unconstrained Optimization Reformulations of Equilibrium Problems

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Acta Mathematica Sinica,English Series 2009年第3期25卷 343-354页

作者： Li Ping ZHANG ji ye HAN w Department of Mathematical Sciences Tsinghua University Beijing 100084 P. R. China Institute of Applied Mathematics Academy of Mathematics & Systems Science Chinese Academy of Sciences Beijing 100190 P. R. China

We generalize the D-gap function developed in the literature for variational inequalities to a general equilibrium problem （EP）. Through the D-gap function, the equilibrium problem is cast as an unconstrained minimization problem. We give conditions under which any stationary point of the D-gap function is a solution of EP and conditions under which it provides a global error bound for EP. Finally, these results are applied to box-constrained EP and then weaker conditions are established to obtain the desired results for box-constrained EP.

关键词： equilibrium problems D-gap function error bound unconstrained optimization

Secular Changes of Stature in Rural Children and Adolescents in China, 1985-2010

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Biomedical and Environmental Sciences 2014年第8期27卷 573-581页

作者： CHEN Tian jiao ji Cheng ye Institute of Child and Adolescent Health School of Public Health Peking University Health Science Center

Objective To analyze and assess secular change in stature in rural children and adolescents in China from 1985 to 2010. Methods Data were obtained from the 6 rounds of the Chinese National Survey on Student＇s Constitution and Health. The subjects enrolled in the study were children and adolescents aged 7-18 years in rural areas of provincial capitals. Results An overall positive secular trend in stature occurred in rural areas of provincial capitals in China from 1985 to 2010. The overall average increase rates were 3.1 and 2.4 cm/decade for boys and girls, respectively. The total body height increases for grown up boys and girls were 3.6 and 2.3 cm and the increase rates were 1.4 and 0.9 cm/decade, respectively. There were differences in body height increase among eastern, central and western regions. The average body height of the children or adolescents in eastern region was highest, followed by central region and western region. The overall increase rates in central region were highest among the three regions. The difference between eastern/central region and western region was obvious. 〈br〉 Conclusion Positive secular trend in stature of children or adolescents has occurred in rural area of China, and rural boys and girls showed a great potential for continuous growth. More attention should be paid to the differences in children＇s body height between western region and eastern/central region.

关键词： Secular change Stature Rural population Regional difference Child and adolescent

Numerical Study on Characteristics of Supercavitating Flow Around the Variable-Lateral-Force Cavitator

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China Ocean Engineering 2017年第1期31卷 123-129页

作者： hu Xiao GAO ye SHI Xiao-tao College of Hydraulic and Environmental Engineering China Three Gorges University Yichang 443008 China Engineering Research Center of Eco-environment in Three Gorges Reservoir Region Ministry of Education China Three Gorges University Yichang 443008 China Department of Aerospace and Building Engineering Harbin Engineering University Harbin 150001 China

A control scheme named the variable-lateral-force cavitator, which is focused on the control of lift force, drag force and lateral forces for underwater supercavity vehicles was proposed, and the supercavitating flow around the cavitator was investigated numerically using the mixture multiphase flow model. It is verified that the forces of pitching, yawing, drag and lift, as well as the supercavity size of the underwater vehicle can be effectively regulated through the movements of the control element of the variable-lateral-force cavitator in the radial and circumferential directions. In addition, if the control element on either side protrudes to a height of 5% of the diameter of the front cavitator, an amount of forces of pitching and yawing equivalent to 30% of the drag force will be produced, and the supercavity section appears concave inwards simultaneously. It is also found that both the drag force and lift force of the variable-lateral-force cavitator decline as the angle of attack increases.

关键词： supercavitating flow cavitator drag force lateral forces numerical investigation

Collision risk-capacity tradeoff analysis of an en-route corridor model

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Chinese Journal of Aeronautics 2014年第1期27卷 125-135页

作者： ye Bojia hu Minghua John Friedrich Shortle College of Civil Aviation Nanjing University of Aeronautics and Astronautics National Key Laboratory of Air Traffic Flow Management Nanjing University of Aeronautics and Astronautics Center for Air Transportation Systems Research George Mason University

Flow corridors are a new class of trajectory-based airspace which derives from the next generation air transportation system concept of operations. Reducing the airspace complexity and increasing the capacity are the main purposes of the en-route corridor. This paper analyzes the collision risk-capacity tradeoff using a combined discrete-continuous simulation method. A basic two-dimensional en-route flow corridor with performance rules is designed as the operational envi- ronment. A second-order system is established by combining the point mass model and the propor- tional derivative controller together to simulate the self-separation operations of the aircrafts in the corridor and the operation performance parameters from the User Manual for the Base of Aircraft Data are used in this research in order to improve the reliability. Simulation results indicate that the aircrafts can self-separate from each other efficiently by adjusting their velocities, and rationally set- ting the values of some variables can improve the rate and stability of the corridor with low risks of loss of separation.

关键词： Air traffic control Corridor Risk-capacity tradeoff Self-separation Simulation

Whole-genome sequencing opens a new era for molecular breeding of grass carp(Ctenopharyngodon idellus)

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Science China(Life Sciences) 2015年第6期58卷 619-620页

作者： hu Wei CHEN ji State Key Laboratory of Freshwater Ecology and Biotechnology Institute of Hydrobiology Chinese Academy of Sciences

Recently, the genome sequencing of the grass carp （Cte- nopharyngodon idellus） has been jointly completed by re- searchers from Institute of Hydrobiology （Chinese Academy of Sciences）, National Center for Gene Research, and Sun Yat-Sen University. Adopting a whole-genome shotgun sequencing strategy and modified de novo Phusionmeta assembly pipeline, researchers obtained a 0.9 GB draft genome of a female adult grass carp and a 1.07 GB genome of a wild male.

关键词：全基因组测序草鱼分子育种中国科学院中山大学生物研究所鸟枪法测序基因组草图

The green-emitting fluorescence of nano Y_2O_3:Er^(3+) under different excitations

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Science China(Physics,Mechanics & Astronomy) 2012年第7期55卷 1152-1157页

作者： ji RuoNan ye YanXi hu XiaoYun FAN Jun LIU EnZhou ZHANG Qian ZHAO ChaoShuai ye SiWen Physics Department of Northwest University Xi'an 710069China School of Chemical Engineering Northwest University Xi'an 710069China Fuzhou Software Technology Vocational College Fuzhou 350003China

The green-emitting fluorescent powders of nano Y2O3：Er^3＋ were fabricated by the coprecipitation method. The X-ray diffrac- tion pattern shows that as-prepared Y2O3：Er^3＋ is the cubic phase crystal with a grain size of about 30 nm. The UV-Vis spec- trum indicates Y^O3：Er^3＋ exhibits five ultraviolet visible absorption peaks at 365, 377, 489, 521 and 652 nm respectively. Meanwhile, the fluorescence spectra of Y2O3：Er^3＋ display four emission peaks at 522, 537, 550 and 562 nm at the excitation of 365,377 and 521 nm, respectively. The green-emitting fluorescent mechanism of Y2O3：Er^3＋ is proposed as well. Additionally, the temperature dependence of fluorescence properties and metal Ag fluorescence enhancement effect are investigated. Results show that increasing the annealing temperature and metal Ag doping both can enhance the fluorescence intensity. The maxi- mum enhancement is 87.5% after Ag is doped.

关键词： nano Y2O3:Er^3+ coprecipitation method luminous properties localized surface plasmon resonance fluorescence enhancement

Molecular characterization and functional analysis of daf-8 in the pinewood nematode,Bursaphelenchus xylophilus

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Journal of Forestry Research 2022年第2期33卷 689-698页

作者： jinghan Wang huan Hong Rong Xie jingjing ji Kai Guo Liqun Bai jia Tang Hongshi Yu jianren ye jiafu hu Nanjing Forestry University Nanjing 210037China Zhejiang Agricultural and Forestry University Hangzhou 311300China Yuhuan Natural Resources and Planning Bureau Taizhou 317600China School of BioSciences The University of MelbourneParkvilleVIC 3010Australia

Bursaphelenchus xylophilus,causal agent of pine wilt disease,causes extensive damage ***-gies are needed to inhibit population growth or block the spread of the invasive nematode to control pine wilt *** gene daf-8 plays crucial roles in larval develop-ment and dauer formation in Caenorhabditis elegans,but little is known about its orthologue in *** the present molecular characterization and functional analysis of daf-8 in ***(Bx-daf-8),RT-qPCR showed that the expression of Bx-daf-8 gradually increased during the embryonic stage,peaked in the second-stage juvenile(J2),then dramatically dropped in the J3,and remained at that low level for the rest of its ***-daf-8-transgenic *** was employed to mimic the spatiotemporal expression of Bx-daf-8,which was expressed close to the pharynx during early embryogenesis and weakly throughout the whole body during late *** was observed in head neurons and tail ganglions throughout all postembryonic *** embryos were severely abnormal,and hatching rate decreased sharply after Bx-daf-8 ***-16-1 and da-f16-2,downstream genes in the IIS pathway,also dropped sharply after Bx-daf-8 *** propose that TGFβmay crosstalk with the IIS pathway upstream of Bx-daf-16 and that daf-8 may act as a master regulator of daf-16 in ***,knockdown of Bx-daf-8 did not lead to constitutive developmental arrest at the dauer larval stage,indicating that dauer entry in *** might be controlled by several genes and is more complicated than in ***-daf-8 alone did not control the dauer entry in ***,but it was indispensable for embryogen-esis,providing a potential target for suppressing population growth of ***.

关键词： Daf-8 Expression pattern RNAi Embryogenesis Bursaphelenchus xylophilus

Waist Circumference Distribution of Chinese School-age Children and Adolescents

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Biomedical and Environmental Sciences 2010年第1期23卷 12-20页

作者： CHENG-ye ji RITA YT SUNG GUAN-SHENG MA JUN MA ZHONG-hu HE TIAN-jiAO CHEN Institute of ChiM and Adolescent Health Peking University Health Science Center Beijing 100191 China Department of Paediatrics The Chinese University of Hong Kong Hong Kong Special Administrative Region China National Institute for Nutrition and Food Safety Chinese Center for Disease Control and Prevention Beijing 100021 China

Background Waist circumference （WC）, a proxy measure of central body fat, is a better predictor than overall body fat for cardiovascular risk factors in both adults and children. WC cutoffs have been established in many countries, but the national WC reference has not been developed in China. Objective To study the distribution of WC in a representative group of Chinese children for establishing Chinese WC cutoff points. Methods Cross-sectional data obtained from 15 mainland provinces and Hong Kong were collected. There were 160 225 children and adolescents aged 7-18 years old in total. The subjects were divided into five regional groups namely costal city, other city, noah rural, south rural, and Hong Kong, for analyzing the distribution of WC. Results A large variation in WC distribution was found among the five groups for both sexes. Coastal city group had the highest P85 WC values consistently from the early school ages to 18-year-old compared with other groups. In contrast, south rural group had P85 values consistently lagged behind not only the city groups but also the north rural group. Hong Kong group had a high P85 WC at early ages, but because of the smaller increments of WC during adolescence, the P85 curve was gradually exceeded by the north rural groups. Catch-up trend was found in the two rural groups since the peak of puberty. These disparities were caused by not only socioeconomic and urban-rural factors but also north-south differences. Because of the regional variation of WC, a ＂gradient＂ prevalence of central obesity was prospected among these groups. Comparisons of WC distributions between the Chinese and the U.S.A or Netherlands demonstrated the necessary of setting up China＇s own WC cutoffs. Sex and age-specific percentiles were obtained and smoothed by using LMS method. Conclusion The data obtained from this study could be used to develop national WC cutoff points for Chinese children and adolescents.

关键词： Overweight and obesity Central obesity Waist circumference Chinese youth School-age children and adolescents

Resource optimization in wireless powered cooperative mobile edge computing systems

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Science China(Information Sciences) 2021年第8期64卷 56-65页

作者： Qibin ye Weidang LU Su hu Xiaohan XU National Key Laboratory on Communications University of Electronic Science and Technology of China College of Information Engineering Zhejiang University of Technology

Mobile edge computing(MEC) meets the high-bandwidth and ultra-low-latency requirements of mobile networks and improves communication reliability by reducing the networks’ load. In this study, we study a wireless powered MEC system, which includes an access point(AP) and two mobile devices. The endurance of mobile devices can be effectively enhanced using the wireless power transfer technology and user cooperation. However, during user cooperation, a closer user assists a farther user with forwarding tasks by sharing the same bandwidth, which causes interference. To overcome the interference issue, the closer user can instead assist other users in forwarding tasks by using a different bandwidth. We aim to minimize the power of the AP by joint power and bandwidth optimization while satisfying the delay and users’ computational tasks. Simulation results show that the proposed user collaboration method can overcome user interference,reduce energy consumption, and improve user performance compared with the baseline policies.

关键词： mobile edge computing user cooperation wireless power transfer energy consumption resource management