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Precision measurement and compensation of kinematic errors for industrial robots using artifact and machine learning

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Advances in Manufacturing 2022年第3期10卷 397-410页

作者： ling-Bao Kong Yi yu Shanghai Engineering Research Center of Ultra-precision Optical Manufacturing Department of Optical Science and EngineeringFudan UniversityShanghai 200438People's Republic of China

Industrial robots are widely used in various areas owing to their greater degrees of freedom(DOFs)and larger operation space compared with traditional frame movement systems involving sliding and rotational ***,the geometrical transfer of joint kinematic errors and the relatively weak rigidity of industrial robots compared with frame movement systems decrease their absolute kinematic accuracy,thereby limiting their further application in ultraprecision *** imposes a stringent requirement for improving the absolute kinematic accuracy of industrial robots in terms of the position and orientation of the robot arm *** measurement and compensation methods for industrial robots either require expensive measuring systems,producing positioning or orientation errors,or offer low measurement ***,a kinematic calibration method for an industrial robot using an artifact with a hybrid spherical and ellipsoid surface is proposed.A system with submicrometric precision for measuring the position and orientation of the robot arm end is developed using laser displacement ***,a novel kinematic error compensating method involving both a residual learning algorithm and a neural network is proposed to compensate for nonlinear errors.A six-layer recurrent neural network(RNN)is designed to compensate for the kinematic nonlinear errors of a six-DOF industrial *** results validate the feasibility of the proposed method for measuring the kinematic errors of industrial robots,and the compensation method based on the RNN improves the accuracy via parameter *** studies show that the measuring system and compensation method can reduce motion errors by more than 30%.The present study provides a feasible and economic approach for measuring and improving the motion accuracy of an industrial robot at the submicrometric measurement level.

关键词： Industrial robot Kinematic error Calibration Machine learning Recurrent neural network(RNN)

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The GeV emission of PSR B1259–63 during its last three periastron passages observed by Fermi-LAT

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Research in Astronomy and Astrophysics 2018年第12期18卷 89-94页

作者： Zhi Chang Shu Zhang yu-Peng Chen Long Ji ling-da Kong Cong-Zhan Liu Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Institut fur Astronomie und Astrophysik Kepler Center for Astro and Particle PhysicsEberhard Karls UniversitatSand 172076 TubingenGermany University of Chinese Academy of Sciences Beijing 100049China

PSR B1259–63 is a γ-ray emitting high mass X-ray binary system, in which the compact object is a millisecond *** system has an orbital period of 1236.7 d and shows peculiar γ-ray flares when the neutron star moves out of the stellar disk of the companion *** γ-ray flare events were firstly discovered by using Fermi-LAT around the 2010 periastron passage, which was repeated for the 2014 and 2017 periastron *** analyze the Fermi-LAT data for all the three periastron passages and found that in each flare the energy spectrum can be represented well by a simple power *** γ-ray light curves show that in 2010 and 2014 after each periastron there are two main flares,but in 2017 there are four flares including one precursor about 10 d after the periastron *** first main flares in 2010 and 2014 are located at around 35 d after the periastron passage, and the main flare in 2014 is delayed by roughly 1.7 d with respect to that in *** the 2017 flare, the source shows a precursor about 10 d after the periastron passage, but the following two flares become weaker and lag behind those in 2010 by roughly 5 *** strongest flares in 2017 occurred 58 d and 70 d after the periastron *** results challenge the previous models.

关键词： binaries:general pulsars:general gamma rays:general

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FACTORS INFLUENCING THERMAL STRUCTURE IN A TRIBUTARY BAY OF THREE GORGES RESERVOIR

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Journal of Hydrodynamics 2011年第4期23卷 407-415页

作者： yu Zhen-zhen WANG ling-ling College of Water Conservancy and Hydropower Engineering Hohai University Nanjing 210098 China

To better understand the factors influencing the thermal structure of tributaries in the Three Gorges Reservoir （TGR）, a well validated three-dimensional hydrodynamic and water temperature model was proposed to simulate the water temperature distribution in the Xiangxi Bay, a representative tributary of TGR. The numerical results show that water temperature stratification seasonally occurred in the Xiangxi Bay, with stable vertical temperature profiles. It is found from the numerical experiments that three key factors are responsible for the formation of water temperature structure：（1） very often, the locations of thermocline are mainly determined by wind speeds, and the higher the wind speed is, the deeper the thermocline is located beneath the water surface, which could be expressed by a fitted exponential function, （2） the thermal structure is affected by static stability of water column, and the thermocline becomes closer to the water surface and its thickness increases with the increase of temperature, （3） due to the effect of the thermal density inflow, the water temperature of the hypolimnion tends to be uniform, however, even under the condition of larger inflow discharge, the influence of the inflow on the epilitnnion and the thermocline is not significant.

关键词： water temperature stratification numerical simulation density current influencing factors wind force static stability of water inflow discharge Three Gorges Reservoir (TGR)

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Effects of the Dicranopteris linearis root system and initial moisture content on the soil disintegration characteristics of gully erosion

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Journal of Mountain Science 2022年第12期19卷 3548-3567页

作者： HE ling DENG yu-Song TANG Qiu-yue LIAO da-lan WANG Chao DUAN Xiao-qian Guangxi Key Laboratory of Forest Ecology and Conservation College of ForestryGuangxi UniversityNanning 530004China College of Geographical Sciences and Planning Nanning Normal UniversityNanning 530100China

Benggang erosion is caused by a special type of gully erosion in southern China that seriously endangers the local ecology and *** this study,typical Benggang collapsing-wall soils were used as the study area to investigate the effects of different initial moisture contents and dicranopteris linearis root weight densities,as well as their interactions on disintegration in orthogonal test *** results showed that the rate of soil disintegration decreased as a linear function of the initial moisture *** soil disintegration rate tended to rise and then fall as the root weight density increased,reflecting an optimum root weight density of 0.75-1.00 g/100 *** incorporation of dicranopteris linearis roots was most effective for soil consolidation in the shallow layers of *** addition,the disintegration rate of the collapsing-wall soils increases as the soil layer *** dicranopteris linearis root system and initial moisture content had an interactive effect that was more pronounced in deeper ***,the combined effect of these processes was always dominated by the initial moisture *** initial soil moisture content(0.20-0.24 g/g)and the addition of a high root density in dicranopteris linearis(0.75-1.00 g/100 cm3)were the optimal combinations that reduced the disintegration *** conclusion,maintaining a suitable natural moisture content in collapsing-wall soils and taking measures that use plants to consolidate soil can effectively prevent and control the occurrence of Benggang *** results of this study provided further insight into the factors that influence soil disintegration and offered a scientific basis for soil erosion management in the southern China.

关键词： Collapsing wall Initial moisture content Interactive effect Root weight density Soil disintegration

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Improved artificial bee colony algorithm with mutual learning

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Journal of Systems Engineering and Electronics 2012年第2期23卷 265-275页

作者： yu Liu Xiaoxi ling yu Liang Guanghao Liu School of Software Dalian University of Technology Dalian 116024 P. R. China Civil Aviation Flight University of China Guanghan 618307 E R. China

The recently invented artificial bee colony （ABC） al- gorithm is an optimization algorithm based on swarm intelligence that has been used to solve many kinds of numerical function optimization problems. It performs well in most cases, however, there still exists an insufficiency in the ABC algorithm that ignores the fitness of related pairs of individuals in the mechanism of find- ing a neighboring food source. This paper presents an improved ABC algorithm with mutual learning （MutualABC） that adjusts the produced candidate food source with the higher fitness between two individuals selected by a mutual learning factor. The perfor- mance of the improved MutualABC algorithm is tested on a set of benchmark functions and compared with the basic ABC algo- rithm and some classical versions of improved ABC algorithms. The experimental results show that the MutualABC algorithm with appropriate parameters outperforms other ABC algorithms in most experiments.

关键词： artificial bee colony (ABC) algorithm numerical func- tion optimization swarm intelligence mutual learning.

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Estimation of Treatment Effects in Nonlinear Models with Unobserved Confounding

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Acta Mathematicae Applicatae Sinica 2023年第2期39卷 320-336页

作者： yu-ling LI Jun WANG Research Center for Applied Mathematics and Interdisciplinary Sciences Beijing Normal UniversityZhuhai 519087China yunnan Key Laboratory of Statistical Modeling and data Analysis Yunnan UniversityKunming 650091China

Estimation of treatment effects is one of the crucial mainstays in economics and sociology *** problem will become more serious and complicated if the treatment variable is endogenous for the presence of unobserved *** estimation and conclusion are likely to be biased and misleading if the endogeny of treatment variable is *** this article,we propose the pseudo maximum likelihood method to estimate treatment effects in nonlinear *** proposed method allows the unobserved confounding and random error terms to exist in an arbitrary relationship(such as,add or multiply),and the unobserved confounding have different influence directions on treatment variables and outcome *** proposed estimator is consistent and asymptotically normally *** studies show that the proposed estimator performs better than the special regression estimator,and the proposed method is stable for various distribution of error ***,the proposed method is applied to the real data that studies the influence of individuals have health insurance on an individual’s decision to visit a doctor.

关键词： nonlinear models quasi likelihood estimator stable treatment effects unobserved confounding

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Effect of liver inflammation on accuracy of FibroScan device in assessing liver fibrosis stage in patients with chronic hepatitis B virus infection

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World Journal of Gastroenterology 2021年第7期27卷 641-653页

作者： ling-ling Huang Xue-Ping yu Ju-Lan Li Hui-Ming Lin Na-ling Kang Jia-Ji Jiang yue-Yong Zhu yu-Rui Liu da-Wu Zeng Department of Hepatology Hepatology Research InstituteThe First Affiliated HospitalFujian Medical UniversityFuzhou 350005Fujian ProvinceChina Department of Infectious Diseases The First Hospital of Quanzhou Affiliated to Fujian Medical UniversityQuanzhou 362000Fujian ProvinceChina Fujian Key Laboratory of Precision Medicine for Cancer Fujian Key Laboratory of Laboratory MedicineThe First Affiliated HospitalFujian Medical UniversityFuzhou 350005Fujian ProvinceChina

BACKGROUND Transient elastography(FibroScan)is a new and non-invasive test,which has been widely recommended by the guidelines of chronic hepatitis B virus(HBV)management for assessing hepatic fibrosis ***,some confounders may affect the diagnostic accuracy of the FibroScan device in fibrosis *** To evaluate the diagnostic value of the FibroScan device and the effect of hepatic inflammation on the accuracy of FibroScan in assessing the stage of liver fibrosis in patients with HBV *** The data of 416 patients with chronic HBV infection who accepted FibroScan,liver biopsy,clinical,and biological examination were collected from two hospitals *** operating characteristic(ROC)curves were used to analyze the diagnostic performance of FibroScan for assessing the stage of liver *** discordance in fibrosis staging by FibroScan and pathological scores was statistically *** regression and ROC analyses were used to analyze the accuracy of FibroScan in assessing the stage of fibrosis in patients with different degrees of liver inflammation.A non-invasive model was constructed to predict the risk of misdiagnosis of fibrosis stage using *** In the overall cohort,the optimal diagnostic values of liver stiffness measurement(LSM)using FibroScan for significant fibrosis(≥F2),severe fibrosis(≥F3),and cirrhosis(F4)were 7.3 kPa[area under the curve(AUC)=0.863],9.7 kPa(AUC=0.911),and 11.3 kPa(AUC=0.918),*** rate of misdiagnosis of fibrosis stage using FibroScan was 34.1%(142/416 patients).The group of patients who showed discordance between fibrosis staging using FibroScan and pathological scores had significantly higher alanine aminotransferase and aspartate aminotransferase levels,and a higher proportion of moderate to severe hepatic inflammation,compared with the group of patients who showed concordance in fibrosis staging between the two *** inflammation activity over 2(O

关键词： Liver stiffness measurement Fibrosis stage Liver inflammation Hepatitis B virus FibroScan Predictive model

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Attenuating effect of daidzein on polychlorinated biphenyls-induced oxidative toxicity in mouse testicular cells

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第7期9卷 567-571页

作者： da-lei ZHANG yu-ling MI Kai-ming WANG Wei-dong ZENG Cai-qiao ZHANG College of Animal Sciences Zhejiang University Hangzhou 310029 China Department of Physiology College of Medicine Nanehang University Nanehang 330006 China

The attenuating effect of daidzein (daI) on oxidative toxicity induced by Aroclor 1254 (A1254) was investigated in mouse testicular cells. Cells were exposed to A1254 alone or with daI. The oxidative damage was estimated by measuring malondialdehyde (Mda) formation, superoxide dismutase (SOD) activity and glutathione (GSH) content. Results show that A1254 induced a decrease of germ cell number, an elevation in thiobarbituric acid reactive substances (TBARS) but a decrease in SOD activity and GSH content. However, simultaneous supplementation with daI decreased TBARS level and increased SOD activity and GSH content. Consequently, dietary daI may restore the intracellular antioxidant system to attenuate the oxidative toxicity of A1254 in testicular cells.

关键词： daidzein (daI) Polychlorinated biphenyl (PCB) Oxidative damage. Germ cell

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Pressure and velocity cross-spectrum of normal modes in low-frequency acoustic vector field of shallow water and its application

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Journal of Systems Engineering and Electronics 2015年第2期26卷 241-249页

作者： yun yu Qing ling Jiang Xu Naval Academy of Armament

The pressure and horizontal particle velocity combined descriptions in the very low frequency acoustic field of shallow wa- ter integrated with the concept of effective depth of Pekeris wave- guide is proposed, especially the active component of the pressure and horizontal particle velocity cross-spectrum, also called ho- rizontal complex cross acoustic intensity, when only two normal modes are trapped in the waveguide. Both the approximate theo- retic analysis and the numerical results show that the sign of the horizontal complex cross acoustic intensity active component is independent of the range when vertically deployed receiving dual sensors are placed in appropriate depths, the sum of which is equal to the waveguide effective depth, so it can be used to tell whether the sound source is near the surface or underwater; while the range rate is expected to be measured by utilizing the sign distribution characteristic of the reactive component. The further robustness analysis of the depth classification algorithm shows that the existence of shear waves in semi infinite basement and the change of acoustic velocity profiles have few effects on the application of this method, and the seabed attenuation will limit the detection range, but the algorithm still has a good robustness in the valid detection range.

关键词： low frequency acoustic vector field effective depth complex cross acoustic intensity active component target depth classificatio

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Molecular engineering of dendrimer nanovectors for siRNA delivery and gene silencing

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Frontiers of Chemical Science and Engineering 2017年第4期11卷 663-675页

作者： yu Cao Xiaoxuan Liu ling Peng . Aix-Marseille Université CNRS Centre Interdisciplinaire de Nanoscience de Marseille UMR 7325 Equipe Labellisée Ligue Contre le Caner 13288 Marseille France.. State Key Laboratory of Natural Medicines and Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases Center of Drug Discovery Center of Advanced Pharmaceuticals and Biomaterials China Pharmaceutical University Nanjing 210009 China

Small interfering RNA （siRNA） therapeutics hold great promise to treat a variety of diseases, as long as they can be delivered safely and effectively into cells. Dendrimers are appealing vectors for siRNA delivery by virtue of their well-defined molecular architecture and multivalent cooperativity. However, the clinical translation of RNA therapeutics mediated by dendrimer delivery is hampered by the lack of dendrimers that are of high quality to meet good manufacturing practice standard. In this context, we have developed small amphiphilic dendrimers that self-assemble into supramolecular structures, which mimic high-generation dendrimers synthesized with cova- lent construction, yet are easy to produce in large amount and superior quality. Indeed, the concept of supramolecular dendrimers has proved to be very promising, and has opened up a new avenue for dendrimer-mediated siRNA delivery. A series of self-assembling supramolecular dendrimers have consequently been established, some of them out-performing the currently available nonviral vectors in delivering siRNA to various cell types in vitro and in vivo, including human primary cells and stem cells. This short review presents a brief introduction to RNAi therapeutics, the obstacles to their delivery and the advantages of dendrimer delivery vectors as well as our bio-inspired struc^rally flexible dendrimers for siRNA delivery. We then highlight our efforts in creating self- assembling amphiphilic dendrimers to construct supramo- lecular dendrimer nanosystems for effective siRNA delivery as well as the related structural alterations to enhance delivery efficiency. The advent of self-assembling supramolecular dendrimer nanovectors holds great pro- mise and heralds a new era of dendrimer-mediated delivery of RNA therapeutics in biomedical applications.

关键词： gene therapy RNAi therapeutics dendrimer,nanovectors gene silencing

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