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Membership determination of open cluster NGC 188 based on the DBSCAN clustering algorithm

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Research in Astronomy and Astrophysics 2014年第2期14卷 159-164页

作者： xin-hua Gao School of Information Science and Engineering Changzhou University

High-precision proper motions and radial velocities of 1046 stars are used to determine member stars using three-dimensional （3D） kinematics for open clus- ter NGC 188 based on the density-based spatial clustering of applications with noise （DBSCAN） clustering algorithm. By implementing this algorithm, 472 member stars in the cluster are obtained with 3D kinematics. The color-magnitude diagram （CMD） of the 472 member stars using 3D kinematics shows a well-defined main sequence and a red giant branch, which indicate that the DBSCAN clustering algorithm is very effective for membership determination. The DBSCAN clustering algorithm can ef- fectively select probable member stars in 3D kinematic space without any assumption about the distribution of the cluster or field stars. Analysis results show that the CMD of member stars is significantly clearer than the one based on 2D kinematics, which al- lows us to better constrain the cluster members and estimate their physical parameters. Using the 472 member stars, the average absolute proper motion and radial velocity are determined to be （PMα, PMδ） = （-2.58 ± 0.22, ＋0.17 ± 0.18） mas yr-1 and Vr = -42.35 ± 0.05 km s-1, respectively. Our values are in good agreement with values derived by other authors.

关键词： Galaxy: open clusters and associations: individual (NGC 188) -- stars:kinematics -- Hertzsprung-Russell diagram -- techniques: radial velocities

An application of the KNND method for detecting nearby open clusters based on Gaia-DR1

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Research in Astronomy and Astrophysics 2017年第6期17卷 89-94页

作者： xin-hua Gao School of Information Science and Engineering Changzhou University Changzhou 213164 China

This paper presents a preliminary test of the k-th nearest neighbor distance （KNND） method for detecting nearby open clusters based on Gaia-DR1. We select 38 386 nearby stars （〈 100 pc） from the Gaia-DR1 catalog, and then use the KNND method to detect overdense regions in three-dimensional space. We find two overdense regions （the Hyades and Coma Berenices （Coma Ber） open clusters）, and obtain 57 reliable cluster members. Based on these cluster members, the distances to the Hyades and Coma Ber clusters are determined to be 46.0±0.2 and 83.5±0.3 pc, respectively. Our results demonstrate that the KNND method can be used to detect open clusters based on a large volume of astrometry data.

关键词： open clusters and associations individual (Hyades, Coma Ber) - astrometry- parallaxes- stars distances

Structure stability, electronic property and voltage profile of LiFe_(1-n)NnP_(1-m)M_(m)O_(4) olivine cathode material

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Rare Metals 2021年第12期40卷 3512-3519页

作者： Zhi-Hong Cui Xue-Feng Lu Jian-hua luo xin Guo Hong-Tao Xue Fu-Ling Tang State Key Laboratory of Advanced Processing and Recycling of Non-ferrous Metal Department of Materials Science and EngineeringLanzhou University of TechnologyLanzhou 730050China

First-principles computational studies under density functional theory(DFT) framework were used to investigate the structural stability, conductivity and voltage profile of LiFe_(1-n)NnP_(1-m)M_(m)O_(4)(N, M = Si or S) electrode materials. It is found that the Li FeP_(7/8)Si_(1/8)O_(4) system has the most stable structure. After doping, the band gap values of the systems decrease gradually, and LiFe_(7/8)S_(1/8)PO_(4) system has a minimum band gap of 1.553 e V, attributed to the hybridization of the Fe-d and S-p orbital electrons. The Li Fe P7/8 S1/8 O4 system demonstrates the characteristic of n-type semiconductor, and other doping systems have the feature of p-type semiconductor. Charge density difference maps show that the covalent property of Si-O bond is enhanced in the Li FeP_(7/8)Si_(1/8)O_(4) system. The average distance of Li and O atoms in the S doping systems increases from 0.21026 to 0.21486 and 0.21129 nm, respectively,indicating that doping broadens significantly the channel of Li ion de-intercalation in LiFe_(7/8)S_(1/8)PO_(4) and LiFeP_(7/8)S_(1/8)O_(4). Additionally, the results of lithium intercalation potential imply that the voltages of the doping systems fallinto the range of 2.23-2.86 V.

关键词： Energy storage materials First principles Battery cathode LiFePO_(4) Doping Electronic properties

Assessment of recoverable oil and gas resources by in-situ conversion of shale——Case study of extracting the Chang 7_(3) shale in the Ordos Basin

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Petroleum Science 2022年第2期19卷 441-458页

作者： Lian-hua Hou Xia luo Sen-Hu Lin Yong-xin Li Li-Jun Zhang Wei-Jiao Ma Research Institute of Petroleum Exploration&Development PetroChinaBeijing100083China National Energy Tight Oil&Gas R&D Center Beijing100083China School of Geosciences China University of PetroleumQingdaoShandong266580China

The purpose of this study is to investigate the entire evolution process of shales with various total organic contents(TOC)in order to build models for quantitative evaluation of oil and gas yields and establish methods for assessing recoverable oil and gas resources from in-situ conversion of organic matters in *** simulation experiments under in-situ conversion conditions were conducted on Chang 7_(3) shales from the Ordos Basin in a semi-open system with large *** results showed that TOC and R_(o) were the key factors affecting the in-situ transformation potential of *** remaining oil and gas yields increased linearly with TOC but inconsistently with R_(o).R_(o) ranged 0.75%—1.25%and 1.05%—2.3%,respectively,corresponding to the main oil generation stage and gas generation stage of shale in-situ *** a model to evaluate the remaining oil/gas yield with TOC and R_(o) was *** TOC of shale suitable for in-situ conversion should be greater than 6%,whereas its R_(o) should be less than 1.0%.Shales with 0.75%(R_(o))could obtain the best economic *** results provided a theoretical basis and evaluation methodology for predicting the hydrocarbon resources from in-situ conversion of shale and for the identification of the optimum“sweet spots”.The assessment of the Chang 7_(3) shale in the Ordos Basin indicated that the recoverable oil and gas resources from in-situ conversion of organic matters in shale are substantial,with oil and gas resources reaching approximately 450×10^(8) t and 30×10^(12)m^(3),respectively,from an area of 4.27×10^(4) km^(2).

关键词： Shale oil In-situ conversion processing Thermal simulation experiment Hydrocarbon generation mechanism Hydrocarbon resource Ordos basin

Data Driven Vibration Control:A Review

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IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 1898-1917页

作者： Weiyi Yang Shuai Li xin luo Chongqing Institute of Green and Intelligent Technology Chinese Academy of SciencesChongqing 400714 Chongqing School University of Chinese Academy of SciencesChongqing 400714China Faculty of Information Technology and Electrical Engineering University of OuluOulu 90570 VTT-Technology Research Center of Finland Oulu 90570Finlan College of Computer and Information Science Southwest UniversityChongqing 400715China

With the ongoing advancements in sensor networks and data acquisition technologies across various systems like manufacturing,aviation,and healthcare,the data driven vibration control(DDVC)has attracted broad interests from both the industrial and academic *** shaping(IS),as a simple and effective feedforward method,is greatly demanded in DDVC *** convolves the desired input command with impulse sequence without requiring parametric dynamics and the closed-loop system structure,thereby suppressing the residual vibration *** on a thorough investigation into the state-of-the-art DDVC methods,this survey has made the following efforts:1)Introducing the IS theory and typical input shapers;2)Categorizing recent progress of DDVC methods;3)Summarizing commonly adopted metrics for DDVC;and 4)Discussing the engineering applications and future trends of *** doing so,this study provides a systematic and comprehensive overview of existing DDVC methods from designing to optimizing perspectives,aiming at promoting future research regarding this emerging and vital issue.

关键词： Data driven vibration control(DDVC) data science designing method feedforward control industrial robot input shaping optimizing method residual vibration

An Overview of Calibration Technology of Industrial Robots

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IEEE/CAA Journal of Automatica Sinica 2021年第1期8卷 23-36页

作者： Zhibin Li Shuai Li xin luo the School of Computer Science and Technology Dongguan University of TechnologyDongguanGuangdong 523808 the School of Computer Science and Technology Chongqing University of Posts and TelecommunicationsChongqing 400065China the Department of Electronics and Electrical Engineering Swansea UniversitySwansea SA18EN the Hengrui(Chongqing)Artificial Intelligence Research Center Department of Big Data Analyses TechniquesCloudwalkChongqing 401331China the Department of Electronics and Electrical Engineering Swansea UniversitySwansea SA18ENUK

With the continuous improvement of automation,industrial robots have become an indispensable part of automated production *** widely used in a number of industrial production activities,such as spraying,welding,handling,etc.,and have a great role in these ***,the robotic technology is developing towards high precision,high *** calibration technology has a great significance to improve the accuracy of ***,it has much work to be done in the identification of robot *** parameter identification work of existing serial and parallel robots is *** the one hand,it summarizes the methods for parameter calibration and discusses their advantages and *** the other hand,the application of parameter identification is *** overview has a great reference value for robot manufacturers to choose proper identification method,points further research areas for ***,this paper analyzes the existing problems in robot calibration,which may be worth researching in the future.

关键词： Absolute pose accuracy identification method industrial robots parameter identification robot calibration technology robot parameters

Cryptocurrency Transaction Network Embedding From Static and Dynamic Perspectives: An Overview

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IEEE/CAA Journal of Automatica Sinica 2023年第5期10卷 1105-1121页

作者： Yue Zhou xin luo MengChu Zhou the School of Computer Science and Technology Chongqing University of Posts and TelecommunicationsChongqing 400065 the Chongqing Key Laboratory of Big Data and Intelligent Computing Chongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714 the Chongqing School University of Chinese Academy of SciencesChongqing 400714China the College of Computer and Information Science Southwest UniversityChongqing 400715China the School of Information and Electronic Engineering Zhejiang Gongshang UniversityHangzhou 310018China the Helen and John C.Hartmann Department of Electrical and Computer Engineering New Jersey Institute of TechnologyNewark NJ 07102 USA

Cryptocurrency, as a typical application scene of blockchain, has attracted broad interests from both industrial and academic communities. With its rapid development, the cryptocurrency transaction network embedding(CTNE) has become a hot topic. It embeds transaction nodes into low-dimensional feature space while effectively maintaining a network structure,thereby discovering desired patterns demonstrating involved users' normal and abnormal behaviors. Based on a wide investigation into the state-of-the-art CTNE, this survey has made the following efforts: 1) categorizing recent progress of CTNE methods, 2) summarizing the publicly available cryptocurrency transaction network datasets, 3) evaluating several widely-adopted methods to show their performance in several typical evaluation protocols, and 4) discussing the future trends of CTNE. By doing so, it strives to provide a systematic and comprehensive overview of existing CTNE methods from static to dynamic perspectives,thereby promoting further research into this emerging and important field.

关键词： Big data analysis cryptocurrency transaction network embedding(CTNE) dynamic network network embedding network representation static network

Impact of thermal stratification on airborne transmission risk of SARS-CoV-2 in various indoor environments

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Building Simulation 2023年第7期16卷 1159-1172页

作者： Fan Liu Zhiwen luo hua Qian School of Environment and Architecture University of Shanghai for Science and TechnologyShanghaiChina Welsh School of Architecture Cardiff UniversityCardiffUK School of Energy and Environment Southeast UniversityNanjingChina

There exist various vertical temperature gradients in different-type buildings.A holistic understanding of the impact of different temperature-stratified indoor environments on infection risk is *** this work,the airborne transmission risk of SARS-CoV-2 in different thermally stratified indoor environments is assessed using our previously developed airborne infection risk *** show that the vertical temperature gradients in office building,hospital,classroom,*** within the range of−0.34 to 3.26℃/*** large space such as coach station,airport terminal,and sport hall,the average temperature gradient ranges within 0.13–2.38℃/m in occupied zone(0–3 m);in ice rink with special requirements of indoor environment,the temperature gradient is higher than those in the above indoor *** existence of temperature gradients causes multi-peaks of the transmission risk of SARS-CoV-2 with distancing,and our results show that in office,hospital ward and classroom,the second peak of the transmission risk is higher than 10^(−3)in most contact scenarios,while most being lower than 10^(−6)in large spaces like coach station and *** work is expected to provide some guidance on specific intervention policies in relation to the types of indoor environments.

关键词： SARS-CoV-2 temperature gradient different-type buildings transmission risk

Shares Differences of Greenhouse Gas Emissions Calculated with GTP and GWP for Major Countries

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Advances in Climate Change Research 2013年第2期4卷 127-132页

作者： WANG Chang-Ke luo xin-Zheng ZHANG hua Laboratory for Climate Studies National Climate Center China Meteorological Administration Yantai University

The global warming potential (GWP) and global temperature potential (GTP) are two common metrics to calculate the CO2 equivalent of greenhouse gases (GHGs). If the country's GHG emissions are calculated with GTP instead of GWP, the shares of the EU, USA, Japan, Canada and South Africa rise in the period 1990-2005, and those of Brazil, Australia, China, India, Mexico and Russia decrease. From 2015 to 2030, the projected shares of the EU, USA, Japan and China will increase, but those of Russia, Canada, Australia, India, Mexico and Brazil will decrease. The reduced shares of Brazil and Australia and increased share of the EU might be one of the important reasons that Brazil and Australia suggested to adopt GTP instead of GWP as early as possible, but the EU opposed it.

关键词： greenhouse gas global warming potential global temperature potential