检索结果-南通市图书馆

Large-scale spatial data visualization method based on augmented reality

虚拟现实与智能硬件（中英文） 2024年第2期6卷 132-147页

作者： Xiaoning QIAO Wenming XIE Xiaodong PENG Guangyun LI Dalin LI Yingyi GUO Jingyi REN Key Laboratory of Electronics and Information Technology for Space Systems National Space Science CenterChinese Academy of SciencesBeijing 100190China University of Chinese academy of sciences Beijing 100049China ordnance science and Research academy of china Beijing 100089China

Background A task assigned to space exploration satellites involves detecting the physical environment within a certain space.However,space detection data are complex and abstract.These data are not conducive for researchers'visual perceptions of the evolution and interaction of events in the space environment.Methods A time-series dynamic data sampling method for large-scale space was proposed for sample detection data in space and time,and the corresponding relationships between data location features and other attribute features were established.A tone-mapping method based on statistical histogram equalization was proposed and applied to the final attribute feature data.The visualization process is optimized for rendering by merging materials,reducing the number of patches,and performing other operations.Results The results of sampling,feature extraction,and uniform visualization of the detection data of complex types,long duration spans,and uneven spatial distributions were obtained.The real-time visualization of large-scale spatial structures using augmented reality devices,particularly low-performance devices,was also investigated.Conclusions The proposed visualization system can reconstruct the three-dimensional structure of a large-scale space,express the structure and changes in the spatial environment using augmented reality,and assist in intuitively discovering spatial environmental events and evolutionary rules.

关键词： Large-scale spatial data analysis Visual analysis technology Augmented reality 3D reconstruction Space environment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Micro defects formation and dynamic response analysis of steel plate of quasi-cracking area subjected to explosive load

引用

Defence Technology（防务技术） 2024年第1期31卷 580-593页

作者： Zheng-qing Zhou Ze-chen Du Xiao Wang Hui-ling Jiang Qiang Zhou Yu-long Zhang Yu-zhe Liu Pei-ze Zhang Research Institute of Macro-Safety science University of Science and TechnologyBeijing100083China School of Civil and Resource Engineering University of Science and Technology BeijingBeijing100083China School of Mechanical Engineering Nantong UniversityNantong226019China china North Industry Advanced Technology Generalization Institute Beijing100089China china academy of ordnance science China

As the protective component,steel plate had attracted extensive attention because of frequently threats of explosive loads.In this paper,the evolution of microstructure and the mechanism of damage in the quasi-cracking area of steel plate subjected to explosive load were discussed and the relationships between micro defects and dynamic mechanical response were revealed.After the explosion experiment,five observation points were selected equidistant from the quasi-cracking area of the section of the steel plate along the thickness direction,and the characteristics of micro defects at the observation points were analyzed by optical microscope(OM),scanning electron microscope(SEM) and electron backscattered diffraction(EBSD).The observation result shows that many slip bands(SBs) appeared,and the grain orientation changed obviously in the steel plate,the two were the main damage types of micro defects.In addition,cracks,peeling pits,grooves and other lager micro defects were appeared in the lower area of the plate.The stress parameters of the observation points were obtained through an effective numerical model.The mechanism of damage generation and crack propagation in the quasicracking area were clarified by comparing the specific impulse of each observation point with the corresponding micro defects.The result shows that the generation and expansion of micro defects are related to the stress area(i.***.the upper compression area,the neutral plane area,and the lower tension area).The micro defects gather and expand at the grain boundary,and will become macroscopic damage under the continuous action of tensile stress.Besides,the micro defects at the midpoint of the section of the steel plate in the direction away from the explosion center(i.***.the horizontal direction) were also studied.It was found that the specific impulse at these positions were much smaller than that in the thickness direction,the micro defects were only SBs and a few micro cracks,and the those decreased with the increase of the distance from the e

关键词： Explosive load Quasi-cracking area Micro defects Steel plate Dynamic response Numerical simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Riverine sulfate sources and behaviors in arid environment,Northwest china:Constraints from sulfur and oxygen isotopes

引用

Journal of Environmental sciences 2024年第3期137卷 716-731页

作者： Yifu Xu Wenjing Liu Bing Xu Zhifang Xu Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation academy for Earth science Chinese Academy of SciencesBeijing 100029China University of Chinese academy of sciences Beijing 100049China

The fate of riverine sulfate ion (SO_(4)^(2-)) and its environmental effects in arid environment are difficult to evaluate due to its complicated sources and strongly coupled behaviors with water cycle which is significantly modified by humans.To understand the sulfur cycle in aquatic systems in arid environment,the chemical and sulfur and oxygen isotopic compositions (δ^(34)S_(SO4)and δ^(18)O_(SO4)) of major rivers around the Badain Jaran Desert,northwestern china,were investigated.These rivers had averaged SO_(4)^(2-)content at 1336μmol/L,over 10times higher than the global average.The δ^(34)S_(SO4)and δ^(18)O_(SO4)values ranged from-5.3‰to+11.8‰and+1.6‰to+12.8‰,respectively.The end-member analysis and the inverse model showed that riverine sulfate was mainly derived from evaporites dissolution (0-87%),sulfide oxidation (13%-100%) and precipitation (0-33%),indicating heterogeneity in sulfur sources and behaviors along the river drainage with the lithology variations and climate gradients.Multiple isotopic tools combining with hydro-chemistry compositions could be applied to reveal sulfur cycle in arid environment.Based on the calculation,sulfide oxidation plays the primary role in the headwater and upstream in the Qilian-Mountains area,where sulfide is widely exposed.While the proportion of evaporites dissolution contributing to riverine sulfate is much higher in downstream in a drier environment.Besides,less precipitation and higher temperature can lead to more intensive evaporation,affecting the process of sulfide oxidation and enhancing the rates of evaporites dissolution and sulfate precipitation in the basin.

关键词： Sulfur and oxygen isotopes Source apportionment Inverse model Arid environment Inland rivers Northwestern china

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Preparation of Modified UiO-66 Catalyst and Its Catalytic Performance for NH_(3)-SCR Denitration

引用

Journal of Wuhan University of Technology(Materials science) 2024年第2期39卷 261-267页

作者：吴彦霞梁海龙 CHEN Yufeng HU Liming WANG Chunpeng Ceramics science Institute China Building Materials AcademyBeijing 100002China

Zirconium-based metal-organic framework UiO-66 was successfully prepared by solvothermal method,and UiO-66 was modified by adding regulators such as formic acid,acetic acid,and hydrochloric acid.The NH_(3)-SCR reactivity of the samples was evaluated by the denitration activity evaluation system,and the UiO-66 and the regulator-modified UiO-66 were characterized by XRD,SEM,BET,FTIR,TG,NH_(3)-TPD,etc.,the effects of regulator types on the structure and properties of UiO-66 were investigated.The experimental results show that,after adding the modifier,the morphology of UiO-66 changes from irregular quadrilateral with serious agglomeration to particles with regular crystal shape and good dispersibility,and the crystal morphology of the catalyst is improved.In addition,after adding the modifier,UiO-66 has a larger specific surface area and stronger surface acidity,which optimizes the catalytic performance of UiO-66.The catalytic performance test results of NH_(3)-SCR show that the low-temperature activity of UiO-66 is poor,and it only shows a certain catalytic activity at higher temperatures.The catalytic activity of UiO-66 was significantly improved after adding the regulator.Among them,the UiO-66-HCl modified with hydrochloric acid had the best catalytic activity,and the denitration rate reached 70%when the denitration temperature was 380℃.

关键词： UiO-66 catalyst catalytic denitration NH_(3)-SCR modified

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Understanding Human and Machine Interaction from Decision Perspective: An Empirical Study Based on the Game of Go

引用

Journal of Systems science & Complexity 2024年第2期37卷 647-667页

作者： ZHAO Ping LI Xuerong WANG Shouyang academy of Mathematics and Systems science Chinese Academy of SciencesBeijing 100190China School of Mathematical sciences University of Chinese Academy of SciencesBeijing 100190China

The authors aim to interpret human and AI interactions from the decision perspective.The authors decompose the interaction analysis into the following main components in the context of interactions:Individual behavior patterns,interaction relationships,and comprehensive analysis.The authors interpret intertemporal decisions from a physical perspective and employ cross-discipline concepts and methodologies to extract the behavior characteristics of players in the empirical case study.About the individual behavior patterns,the authors find that human players prefer short-term periods to AI in decision-making.The interaction relationship analysis reveals a dynamic relationship between possible short-term co-movement and nearly counter-movement in the long run.The authors apply principal component analysis to descriptive indicators and discover a regular decision hierarchy.The main behavior pattern of players in the game of Go is switching between careful and daring behaviors.The differences in the decision hierarchies imply a discrepancy of patience between humans and AI.

关键词： Coherence analysis decision hierarchy machine behaviour multitaper spectral analysis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Enhancing cut selection through reinforcement learning

引用

science china Mathematics 2024年第6期67卷 1377-1394页

作者： Shengchao Wang Liang Chen Lingfeng Niu Yu-Hong Dai academy of Mathematics and Systems science Chinese Academy of SciencesBeijing100190China Research Center on Fictitious Economy and Data science Chinese Academy of SciencesBeijing100190China

With the rapid development of artificial intelligence in recent years,applying various learning techniques to solve mixed-integer linear programming(MILP)problems has emerged as a burgeoning research domain.Apart from constructing end-to-end models directly,integrating learning approaches with some modules in the traditional methods for solving MILPs is also a promising direction.The cutting plane method is one of the fundamental algorithms used in modern MILP solvers,and the selection of appropriate cuts from the candidate cuts subset is crucial for enhancing efficiency.Due to the reliance on expert knowledge and problem-specific heuristics,classical cut selection methods are not always transferable and often limit the scalability and generalizability of the cutting plane method.To provide a more efficient and generalizable strategy,we propose a reinforcement learning(RL)framework to enhance cut selection in the solving process of MILPs.Firstly,we design feature vectors to incorporate the inherent properties of MILP and computational information from the solver and represent MILP instances as bipartite graphs.Secondly,we choose the weighted metrics to approximate the proximity of feasible solutions to the convex hull and utilize the learning method to determine the weights assigned to each metric.Thirdly,a graph convolutional neural network is adopted with a self-attention mechanism to predict the value of weighting factors.Finally,we transform the cut selection process into a Markov decision process and utilize RL method to train the model.Extensive experiments are conducted based on a leading open-source MILP solver SCIP.Results on both general and specific datasets validate the effectiveness and efficiency of our proposed approach.

关键词： reinforcement learning mixed-integer linear programming cutting plane method cut selection

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Study on the optimal incident proton energy of ^(7)Li(p,n)^(7)Be neutron source for boron neutron capture therapy

引用

Nuclear science and Techniques 2024年第3期35卷 170-180页

作者： Yi-Nan Zhu Zuo-Kang Lin Hai-Yan Yu Ye Dai Zhi-Min Dai Xiao-Han Yu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese academy of science Beijing 100049China

Boron neutron capture therapy(BNCT)is recognized as a precise binary targeted radiotherapy technique that effectively eliminates tumors through the^(10)B(n,α)^(7)Li nuclear reaction.Among various neutron sources,accelerator-based sources have emerged as particularly promising for BNCT applications.The^(7)Li(p,n)^(7)Be reaction is highly regarded as a potential neutron source for BNCT,owing to its low threshold energy for the reaction,significant neutron yield,appropriate average neutron energy,and additional benefits.This study utilized Monte Carlo simulations to model the physical interactions within a lithium target subjected to proton bombardment,including neutron moderation by an MgF_(2)moderator and subsequent BNCT dose analysis using a Snyder head phantom.The study focused on calculating the yields of epithermal neutrons for various incident proton energies,finding an optimal energy at 2.7 MeV.Furthermore,the Snyder head phantom was employed in dose simulations to validate the effectiveness of this specific incident energy when utilizing a^(7)Li(p,n)^(7)Be neutron source for BNCT purposes.

关键词： Boron neutron capture therapy ^(7)Li(p,n)7Be neutron source Incident proton energy Monte Carlo simulation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Partial Linear Model Averaging Prediction for Longitudinal Data

引用

Journal of Systems science & Complexity 2024年第2期37卷 863-885页

作者： LI Na FEI Yu ZHANG Xinyu Faculty of science Kunming University of Science and TechnologyKunming 650500China School of Statistics and Mathematics Yunnan University of Finance and EconomicsKunming 650221China academy of Mathematics and Systems science Chinese Academy of SciencesBeijing 100190China

Prediction plays an important role in data analysis.Model averaging method generally provides better prediction than using any of its components.Even though model averaging has been extensively investigated under independent errors,few authors have considered model averaging for semiparametric models with correlated errors.In this paper,the authors offer an optimal model averaging method to improve the prediction in partially linear model for longitudinal data.The model averaging weights are obtained by minimizing criterion,which is an unbiased estimator of the expected in-sample squared error loss plus a constant.Asymptotic properties,including asymptotic optimality and consistency of averaging weights,are established under two scenarios:(i)All candidate models are misspecified;(ii)Correct models are available in the candidate set.Simulation studies and an empirical example show that the promise of the proposed procedure over other competitive methods.

关键词： Asymptotic optimality longitudinal data model averaging estimator partially linear model prediction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A causal multiomics study discriminates the early immune features of Ad5-vectored Ebola vaccine recipients

引用

The Innovation 2024年第3期5卷 77-87页

作者： Zhe Zhang Wenjing Yang Zhengshan Chen Haoang Chi Shipo Wu Wanru Zheng Ruochun Jin Busen Wang Yudong Wang Nan Huo Jinlong Zhang Xiaohong Song Liyang Xu Jun Zhang Lihua Hou Wei Chen Institute of Biotechnology Academy of Military Medical SciencesBeijing 100071China Department of Intelligent Data science College of Computer Science and TechnologyNational University of Defense TechnologyChangsha 410073China Intelligent Game and Decision Lab Academy of Military ScienceBeijing 100091China

The vaccine-induced innate immune response is essential for the generation of an antibody response.To date,how Ad5-vectored vaccines are influenced by preexisting anti-Ad5 antibodies during activation of the early immune response remains unclear.Here,we investigated the specific alterations in GP1,2-specific IgG-related elements of the early immune response at the genetic,molecular,and cellular levels on days 0,1,3,and 7 after Ad5-EBOV vaccination.In a causal multiomics analysis,distinct early immune responses associated with GP1,2-specific IgG were observed in Ad5-EBOV recipients with a low level of preexisting anti-Ad5 antibodies.This study revealed the correlates of the Ad5-EBOV-induced IgG response and provided mechanistic evidence for overcoming preexisting Ad5 immunity during the administration of Ad5-vectored vaccines.

关键词： vaccine immunity alterations

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Threshold Selection and Resource Allocation for Quantized Identification

引用

Journal of Systems science & Complexity 2024年第1期37卷 204-229页

作者： WANG Ying LI Xin ZHAO Yanlong ZHANG Ji-Feng Key Laboratory of Systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China School of Mathematical sciences University of Chinese Academy of SciencesBeijing 100049China

This paper is concerned with the optimal threshold selection and resource allocation problems of quantized identification, whose aims are improving identification efficiency under limited resources. Firstly, the first-order asymptotically optimal quantized identification theory is extended to the weak persistent excitation condition. Secondly, the characteristics of time and space complexities are established based on the Cramér-Rao lower bound of quantized systems. On these basis, the optimal selection methods of fixed thresholds and adaptive thresholds are established under aperiodic signals, which answer how to achieve the best efficiency of quantized identification under the same time and space complexity. In addition, based on the principle of maximizing the identification efficiency under a given resource, the optimal resource allocation methods of quantized identification are given for the cases of fixed thresholds and adaptive thresholds, respectively, which show how to balance time and space complexity to realize the best identification efficiency of quantized identification.

关键词： Quantized output resource allocation system identification threshold selection.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：