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Weight Data Fusion Based on Mutual Support Applied in Large Diameter Measurement

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Chinese Journal of Mechanical Engineering 2009年第4期22卷 562-566页

作者： WANG biao YU Xiaofen xu Congyu School of Instrument Science and Opto-electronic Eng＆eering Hefei University of Technology Hefei 230009 China

The on-line diameter measurement of larger axis workpieces is hard to achieve high precision detection, because of the bad environment of locale, the problem to amend the measuring error by non-uniform temperature field, and the difficulty to collimate and locate by usual method. By improving the measurement accuracy of larger axis accessories, it is useful to raise axis and hole＇s industry produce level. Because of the influence of complex environment in locale and some influential factors which are hard excluded from the large diameter measurement with multi-rolling-wheels method, the measurement results may not support or even contradict each other. To the situation, this paper puts forward a mutual support deviation distinguish data fusion method, including mutual support deviation detection and weight data fusion. The mutual support deviation detection part can effectively remove or weaken the unexpected impact on the measurement results and the weight data fusion part can get more accurate estimate result to the detected data. So the method can further improve the reliability of measurement results and increase the accuracy of the measurement system. By using the weight data fusion based on the mutual support （DFMS） to the simulation and experiment data, both simulation results and experiment results show that the method can effectively distinguish the data influenced by unexpected impact and improve the stability and reliability of measurement results. The new provided mutual support deviation distinguish method can be used to single sensor measurement and multi-sensor measurement, and can be used as a reference in the data distinguish of other area. The DFMS is helpful to realize the diameter measurement expanded uncertainty in 5 ×10^-6D or even higher when the measured axis workpiece＇s diameter is 1-5 m （ 1 m ≤ D ≤5 m ）.

关键词： multi-sensor mutual support weight factor data fusion rolling-wheel

Vernier effect facilitates integrated lithium niobate single-mode lasers

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Science China(Physics,Mechanics & Astronomy) 2022年第3期65卷 133-134页

作者： Xin-biao xu Chang-Ling Zou Key Laboratory of Quantum Information University of Science and Technology of ChinaChinese Academy of SciencesHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China

A research group from Nankai University in China has demonstrated an integrated whispering gallery mode(WGM)microcavity laser on erbium-doped thin-film lithium niobate with a pump threshold of about 200 μW and a side-mode suppression ratio exceeding 26 d B [1]. The Vernier effect is applied to realize the single-mode lasing in a photonic molecule. The work provides a feasible scheme for on-chip single-mode laser for integrated lithium niobate on insulator(LNOI) photonic circuits, and more active devices in LNOI will be developed inspired by this work.

关键词： pump mode lithium

Skeleton-Based Human Action Recognition via Screw Matrices

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Chinese Journal of Electronics 2017年第4期26卷 790-796页

作者： DING Wenwen LIU Kai xu biao CHENG Fei School of Computer Science and Technology Xidian University School of Mathematical Sciences Huaibei Normal University

With the recent advent of low-cost acquisition depth cameras, extracting 3D body skeleton has become relatively easier, which significantly lighten many difficulties in 2D videos including occlusions, shadows and background extraction, etc. Directly perceived features,for example points, lines and planes, can be easily extracted from 3D videos such that we can employ rigid motions to represent skeletal motions in a geometric *** apply screw matrices, acquired by using rotations and translations in 3D space, to model single and multi-body rigid motion. Since screw matrices are members of the special Euclidean group SE(3), an action can be represented as a point on a Lie group, which is a differentiable manifold. Using Lie-algebraic properties of screw algebra, isomorphic to se(3), the classical algorithms of machine learning in vector space can be expanded to manifold space. We evaluate our approached on three public3 D action datasets: MSR Action3 D dataset, UCF Kinect dataset and Florence3D-Action Dataset. The experimental results show that our approaches either match or exceed state-of-the-art skeleton-based human action recognition approaches.

关键词： Skeleton joints Human activity recogni tion Screw algebra Lie group Lie algebra

Safe Efficient Policy Optimization Algorithm for Unsignalized Intersection Navigation

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IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 2011-2026页

作者： Xiaolong Chen biao xu Manjiang Hu Yougang Bian Yang Li Xin xu State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body the College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body the College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082 Wuxi Intelligent Control Research Institute(WICRI)of Hunan University Wuxi 214115China College of Intelligence Science and Technology Institute of Unmanned SystemsNational University of Defense TechnologyChangsha 410073China

Unsignalized intersections pose a challenge for autonomous vehicles that must decide how to navigate them safely and *** paper proposes a reinforcement learning(RL)method for autonomous vehicles to navigate unsignalized intersections safely and *** method uses a semantic scene representation to handle variable numbers of vehicles and a universal reward function to facilitate stable learning.A collision risk function is designed to penalize unsafe actions and guide the agent to avoid them.A scalable policy optimization algorithm is introduced to improve data efficiency and safety for vehicle learning at *** algorithm employs experience replay to overcome the on-policy limitation of proximal policy optimization and incorporates the collision risk constraint into the policy optimization *** proposed safe RL algorithm can balance the trade-off between vehicle traffic safety and policy learning *** intersection scenarios with different traffic situations are used to test the algorithm and demonstrate its high success rates and low collision rates under different traffic *** algorithm shows the potential of RL for enhancing the safety and reliability of autonomous driving systems at unsignalized intersections.

关键词： Autonomous driving decision-making reinforcement learning(RL) unsignalized intersection

Realizing nearly isotropic thermoelectric properties in 2D-layered SnS nanomaterials through highly symmetric metastable-phase powder precursors

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Nano Research 2022年第8期15卷 7713-7722页

作者： Fanshi Wu Junjie Yuan Wenxin Lai Liangwei Fu biao xu School of Chemistry and Chemical Engineering Nanjing University of Science&TechnologyNanjing 210094China State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical EngineeringCollaborative Innovation Center of Advanced MicrostructuresNanjing UniversityNanjing 210093China

Metastable materials offer a broad and novel platform for the development of next-generation science and *** engineering including synthesis of materials with unconventional phases and phase transition of metastable materials has been explored in layered materials but has not tackled their anisotropy issue *** high anisotropy in layered materials further adds the cost of orientation screening of ***,we report the effect of Ag doping on facilitating the formation of metastableπ-cubic phase SnS during the solvothermal synthesis *** this basis,we construct cubic-to-orthorhombic(CTO)samples and elucidate the intrinsic mechanisms of its nearly isotropic thermoelectric properties by characterizing the texturing information and analyzing the valence charge density calculated by density functional theory(DFT).This work demonstrates a convenient approach to synthesize layered materials with isotropic electrical and thermal transport behaviors through a precursor of metastable phase.

关键词： thermoelectric SnS metastable materials anisotropy density functional theory(DFT)

Pancreatic stellate cells promote proliferation and invasiveness of human pancreatic cancer cells via galectin-3

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World Journal of Gastroenterology 2008年第13期14卷 2023-2028页

作者： Hai-biao liang Ming xu Xing-Peng Wang Department of Gastroenterology Shanghai First People's Hospital Affiliated to Shanghai Jiaotong University 85 Wujin Road Shanghai 200080 China

AIM: To investigate the role of pancreatic stellate cells (PSCs) and galectin-3 (GAL-3) in the proliferation and infiltration of pancreatic cancer cell line SW1990. METHODS: Human pancreatic cancer cell line SW1990 and PSCs were cultured in vitro . Supernatant fluid of cultured PSCs and SW1990 cells was collected. Expression of GAL-3 in SW1990 cells and PSCs was detected by ELISA, RT-PCR and Western blotting. Proliferation of cultured PSCs and SW1990 cells was measured by 3-(4, 5-methylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Infiltration of SW1990 cells was detected by a cell infiltration kit. RESULTS: SW1990 cells expressed GAL-3 and this was up-regulated by the supernatant fluid of cultured PSCs. PSCs did not express GAL-3. SW1990 cells stimulated proliferation of PSCs via GAL-3. GAL-3 antibody inhibited SW1990 cell proliferation, while the supernatant fluid of PSCs stimulated proliferation of SW1990 cells through interaction with GAL-3 protein. The supernatant fluid of PSCs enhanced the invasiveness of SW1990 cells through interaction with GAL-3. CONCLUSION: GAL-3 and PSCs were involved in the proliferation and infiltration process of pancreatic cancer cells.

关键词： Cell proliferation Galectin-3 Infiltration Desmoplastic reaction Pancreatic cancer cell Pancreatic stellate cell

Model fitting of the seasonal population dynamics of the soybean aphid, Aphis glycines Matsumura, in the field

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Journal of Integrative Agriculture 2023年第6期22卷 1797-1808页

作者： xu Lei ZHAO Tong-hua XING Xing xu Guo-qing xu biao ZHAO Ji-qiu Institute of Plant Protection Liaoning Academy of Agricultural SciencesShenyang 110161P.R.China Agricultural Technology Extension Center of Xiuyan Manchu Autonomous County Anshan 114300P.R.China

The soybean aphid, Aphis glycines Matsumura(Hemiptera: Aphididae), is one of the greatest threats to soybean production, and both trend analysis and periodic analysis of its population dynamics are important for integrated pest management(IPM). Based on systematically investigating soybean aphid populations in the field from 2018 to 2020, this study adopted the inverse logistic model for the first time, and combined it with the classical logistic model to describe the changes in seasonal population abundance from colonization to extinction in the field. Then, the increasing and decreasing phases of the population fluctuation were divided by calculating the inflection points of the models, which exhibited distinct seasonal trends of the soybean aphid populations in each year. In addition, multifactor logistic models were then established for the first time, in which the abundance of soybean aphids in the field changed with time and relevant environmental conditions. This model enabled the prediction of instantaneous aphid abundance at a given time based on relevant meteorological data. Taken as a whole, the successful approaches implemented in this study could be used to build a theoretical framework for practical IPM strategies for controlling soybean aphids.

关键词： soybean aphid population dynamics logistic model inverse logistic model multifactor logistic model

Equity Study in Health Workforce on Tuberculosis Control in China: a Nationwide Evaluation

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Biomedical and Environmental Sciences 2013年第8期26卷 702-707页

作者： SHI Ying xu biao WANG Wei Bing ZHAO Qi Fu Dan University School of Public Health National Health and Family Planning Commission of the People's Republic of China Bureau of Disease Control

We aimed to describe the distribution of tuberculosis （TB） health workers in China and provide evidences of potential inequity for policy development. We used Lorenz curves and Gini index to characterize the distribution of TB health workers by population size, geographical area and number of annual registered TB cases. An additional stratified analysis was done by three economic regions. The Gini index were 0.33 for population size, 0.62 for geographical area and 0.30 for number of registered tuberculosis cases that indicated an acceptable average, significant inequity and a relative average distribution nationwide respectively.

关键词： TB a Nationwide Evaluation Equity Study in Health Workforce on Tuberculosis Control in China

High thermoelectric properties with low thermal conductivity due to the porous structure induced by the dendritic branching in n-type PbS

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Nano Research 2022年第5期15卷 4739-4746页

作者： Zhenyu Zhu Janak Tiwari Tianli Feng Zhan Shi Yue Lou biao xu School of Chemistry and Chemical Engineering Nanjing University of Science and TechnologyNanjing 210094China Department of Mechanical Engineering The University of UtahSalt Lake CityUT 84112USA State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012China State Key Laboratory of Coordination Chemistry School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210000China

PbS-based thermoelectric materials have attracted extensive attention in recent years for the advantages of earth abundancy and low cost,which is considered to be a substitute for traditional PbTe ***,their high thermal conductivity restricts its ***,in order to improve their thermoelectric performance from reducing the thermal conductivity,a kind of dendritic PbS with controlled crystal grain and morphology are obtained by solution *** adjusting the amount of surfactant(CTAB),the specific formation process of dendrites is *** sintering,the dendritic PbS nanoparticles are easy to form porous structure due to the overlapping and staggered arrangement of dendritic *** comparison,we also prepare a kind of regular octahedral PbS and a dense packing arrangement is formed because of the integrity of the octahedral ***-based Boltzmann transport equation is used to prove the crucial role of porous structure in scattering ***,a maximum zT=1.0 at 773 K in n-type PbS is obtained,which still keep a high-speed growth and is expected to get higher zT value in a higher temperature *** work may shed light to other thermoelectric materials from the formation of porous structure to reduce the thermal conductivity.

关键词： thermoelectric materials lead sulfide solution synthesis porous structure