期刊文献+
共找到196篇文章
< 1 2 10 >
每页显示 20 50 100
A Decision Support System for Spatial Analysis of Agricultural Production in Madagascar
1
作者 Aimé Richard Hajalalaina Solofoson Georges Andriniaina 《Journal of Data Analysis and Information Processing》 2021年第1期1-22,共22页
In this article, our research aims to set up a geo-decisional system, more precisely we are particularly interested in the spatial analysis system of agricultural production in Madagascar. For this, we used the spatia... In this article, our research aims to set up a geo-decisional system, more precisely we are particularly interested in the spatial analysis system of agricultural production in Madagascar. For this, we used the spatial data warehouse technique based on the SOLAP spatial analysis tool. After having defined the concepts underlying these systems, we propose to address the research issues related to them from four points of view: needs study of the Malagasy Ministry of Agriculture, modeling of a multidimensional conceptual model according to the MultiDim model and the implementation of the system studied using GeoKettle, PostGIS, GeoServer, SPAGO BI and Géomondrian technologies. This new system helps improve the decision-making process for agricultural production in Madagascar. 展开更多
关键词 Geo-decisional System Agricultural Production decision-MAKING spatial analysis Data Warehouse MultiDim Model Business Intelligence Madagascar
在线阅读 下载PDF
Spatial Analysis Tool for Urban Environmental Quality Assessment:Leveraging Geoinformatics and GIS
2
作者 Igor Musikhin 《Revue Internationale de Géomatique》 2025年第1期939-957,共19页
Urban environmental quality research is crucial,as cities become competitive centers concentrating human talent,industrial activity,and financial resources,contributing significantly to national economies.Municipal an... Urban environmental quality research is crucial,as cities become competitive centers concentrating human talent,industrial activity,and financial resources,contributing significantly to national economies.Municipal and government priorities include retaining residents,preventing skilled worker outflow,and meeting the evolving needs of urban populations.The study presents the development and application of a scenario-based spatial analysis tool for assessing urban environmental quality at a detailed spatial scale within the city of Novosibirsk.Using advanced geoinformatics,GIS techniques,and an expert knowledge base,the tool integrates diverse thematic data layers with user-defined scenarios to compute and visualize the Scenario-based Urban Environment Quality Index across 87,905 standardized unit areas.The methodology incorporates comprehensive criteria aligned with existing urban planning frameworks and includes demographic targeting to address the city’s heterogeneous population.Validation against expert evaluations demonstrates high accuracy and consistency,while dynamicmodeling capabilities facilitate monitoring the effects of planned urban development initiatives.This approach bridges a critical gap in urban planning by providing granular,data-driven insights that reflect residents’real needs and spatial inequalities.The tool greatly benefits municipal authorities by enabling evidence-based prioritization of interventions,fostering inclusive and sustainable urban growth,and enhancing transparency and participatory governance.Its implementation as a no-code/low-code QGIS plugin ensures wide accessibility and practical application in strategic urban development,marking a significant advancement in urban environment quality assessment science and practice. 展开更多
关键词 Expert knowledge base geographic information system GEOINFORMATICS QGIS plugin scenario-based spatial analysis scenario pattern spatial database urban environmental quality urban planning decision support
在线阅读 下载PDF
Revolutionizing Groundwater Suitability with AI-Driven Spatial Decision Support—A Remote Sensing and GIS Approach for Visakhapatnam District, Andhra Pradesh, India
3
作者 Mallula Srinivasa Rao Gara Raja Rao +1 位作者 Gurram Murali Krishna Kinthada Nooka Ratnam 《Journal of Geographic Information System》 2025年第1期23-44,共22页
This study presents an AI-driven Spatial Decision Support System (SDSS) aimed at transforming groundwater suitability assessments for domestic and irrigation uses in Visakhapatnam District, Andhra Pradesh, India. By e... This study presents an AI-driven Spatial Decision Support System (SDSS) aimed at transforming groundwater suitability assessments for domestic and irrigation uses in Visakhapatnam District, Andhra Pradesh, India. By employing advanced remote sensing, GIS, and machine learning techniques, groundwater quality data from 50 monitoring wells, sourced from the Central Ground Water Board (CGWB), was meticulously analysed. Key parameters, including pH, electrical conductivity, total dissolved solids, and major ion concentrations, were evaluated against World Health Organization (WHO) standards to determine domestic suitability. For irrigation, advanced metrics such as Sodium Adsorption Ratio (SAR), Kelly’s Ratio, Residual Sodium Carbonate (RSC), and percentage sodium (% Na) were utilized to assess water quality. The integration of GIS for spatial mapping and AI models for predictive analytics allows for a comprehensive visualization of groundwater quality distribution across the district. Additionally, the irrigation water quality was evaluated using the USA Salinity Laboratory diagram, providing essential insights for effective agricultural water management. This innovative SDSS framework promises to significantly enhance groundwater resource management, fostering sustainable practices for both domestic use and agriculture in the region. 展开更多
关键词 Groundwater Suitability Geospatial analysis Geospatial Modeling of Water Quality spatial decision support System Remote Sensing Machine Learning Visakhapatnam District
在线阅读 下载PDF
An ontology-based multicriteria spatial decision support system:a case study of house selection 被引量:1
4
作者 Jacek MALCZEWSKI Mohammadreza JELOKHANI-NIARAKI 《Geo-Spatial Information Science》 SCIE EI 2012年第3期177-185,共9页
The paper proposes an ontology-based multicriteria spatial decision support system(MC-SDSS)for the house selection problem.The house selection ontology serves as a foundation for spatial multicriteria decision analysi... The paper proposes an ontology-based multicriteria spatial decision support system(MC-SDSS)for the house selection problem.The house selection ontology serves as a foundation for spatial multicriteria decision analysis(MCDA)in the house selection domain.It is built using the Web Ontology Language(OWL).The ontology represents the spatial MCDA knowledge associated with house selection using semantic machine-interpretable concepts and relationships in such a way that they can be used by machines not just for display purposes,but also for processing,automation,integration,and reuse across applications.It contains concepts(or classes)including quantitative and qualitative criteria(objectives and attributes),decision alternatives(houses for sale),criterion weights,and location attributes of the decision alternatives.The concepts are organized into a hierarchical classification structure using the Analytic Hierarchy Process.To evaluate the decision alternatives,a set of rules is implemented within the OWL knowledge base with the Semantic Web Rule Language.The rules are expressed as combinations of the OWL concepts and their properties.The paper illustrates an implementation of the proposed ontology-based MC-SDSS architecture using a case study of house selection in the City of Tehran,Iran. 展开更多
关键词 GIS multicriteria analysis spatial decision support system ONTOLOGY house selection
原文传递
Combined spatial frequency spectroscopy analysis with visible resonance Raman for optical biopsy of human brain metastases of lung cancers 被引量:1
5
作者 Yan Zhou Cheng-Hui Liu +8 位作者 Yang Pu Binlin Wu Thien An Nguyen Gangge Cheng Lixin Zhou Ke Zhu Jun Chen Qingbo Li Robert R.Alfano 《Journal of Innovative Optical Health Sciences》 SCIE EI CAS 2019年第2期93-104,共12页
The purpose of this study is to examine optical spatial frequency spectroscopy analysis(SFSA)combined with visible resonance Raman(VRR)spectroscopic method,for thefirst time,to discriminate human brain metastases of l... The purpose of this study is to examine optical spatial frequency spectroscopy analysis(SFSA)combined with visible resonance Raman(VRR)spectroscopic method,for thefirst time,to discriminate human brain metastases of lung cancers adenocarcinoma(ADC)and squamous cell carcinoma(SCC)from normal tissues.A total of 31 label-free micrographic images of three type of brain tissues were obtained using a confocal micro-Raman spectroscopic system.VRR spectra of the corresponding samples were synchronously collected using excitation wavelength of 532 nm from the same sites of the tissues.Using SFSA method,the difference in the randomness of spatial frequency structures in the micrograph images was analyzed using Gaussian functionfitting.The standard deviations,calculated from the spatial frequencies of the micrograph images were then analyzed using support vector machine(SVM)classifier.The key VRR biomolecularfingerprints of carotenoids,tryptophan,amide II,lipids and proteins(methylene/methyl groups)were also analyzed using SVM classifier.All three types of brain tissues were identified with high accuracy in the two approaches with high correlation.The results show that SFSA–VRR can potentially be a dual-modal method to provide new criteria for identifying the three types of human brain tissues,which are on-site,real-time and label-free and may improve the accuracy of brain biopsy. 展开更多
关键词 spatial frequency spectroscopy analysis(SFSA) visible resonance Raman(VRR) human brain metastatic lung cancer photomicrograph image support vector machine(SVM)
原文传递
Multi-criteria land evaluation for suitability analysis of wheat:a case study of a watershed in eastern plateau region,India 被引量:5
6
作者 Aditi SARKAR Amit GHOSH Pabitra BANIK 《Geo-Spatial Information Science》 SCIE EI 2014年第2期119-128,共10页
Improper land use results in land degradation as well as decline in agricultural productivity.To obtain optimum benefit from the land,proper utilization of its resources is necessary.Land suitability analysis is the e... Improper land use results in land degradation as well as decline in agricultural productivity.To obtain optimum benefit from the land,proper utilization of its resources is necessary.Land suitability analysis is the evaluation and grouping of specific areas of land in terms of their suitability for a defined use,which is a precondition for sustainable land use planning.This study investigated the applicability of Geographical Information System(GIS)techniques in combination with multi-criteria land evaluation for analysing land suitability.The study used the weighted overlay technique for multi-criteria evaluation with GIS for the assessment of suitability of wheat cultivation in Beko watershed(Purulia,India).The watershed area is moderately suitable for wheat crop production,with constraints like imperfect drainage and poor soil depth. 展开更多
关键词 spatial analysis GIS remote sensing multi-criteria decision analysis spatial decision support system
原文传递
Finite element model updating for large span spatial steel structure considering uncertainties 被引量:4
7
作者 滕军 朱焰煌 +2 位作者 周峰 李惠 欧进萍 《Journal of Central South University》 SCIE EI CAS 2010年第4期857-862,共6页
In order to establish the baseline finite element model for structural health monitoring,a new method of model updating was proposed after analyzing the uncertainties of measured data and the error of finite element m... In order to establish the baseline finite element model for structural health monitoring,a new method of model updating was proposed after analyzing the uncertainties of measured data and the error of finite element model.In the new method,the finite element model was replaced by the multi-output support vector regression machine(MSVR).The interval variables of the measured frequency were sampled by Latin hypercube sampling method.The samples of frequency were regarded as the inputs of the trained MSVR.The outputs of MSVR were the target values of design parameters.The steel structure of National Aquatic Center for Beijing Olympic Games was introduced as a case for finite element model updating.The results show that the proposed method can avoid solving the problem of complicated calculation.Both the estimated values and associated uncertainties of the structure parameters can be obtained by the method.The static and dynamic characteristics of the updated finite element model are in good agreement with the measured data. 展开更多
关键词 model updating UNCERTAINTY interval analysis multi-output support vector regression large span spatial steel structure
在线阅读 下载PDF
A Framework for Intelligent Decision Support System for Traffic Congestion Management System 被引量:2
8
作者 Mohamad K. Hasan 《Engineering(科研)》 2010年第4期270-289,共20页
Traffic congestion problem is one of the major problems that face many transportation decision makers for urban areas. The problem has many impacts on social, economical and development aspects of urban areas. Hence t... Traffic congestion problem is one of the major problems that face many transportation decision makers for urban areas. The problem has many impacts on social, economical and development aspects of urban areas. Hence the solution to this problem is not straight forward. It requires a lot of effort, expertise, time and cost that sometime are not available. Most of the existing transportation planning software, specially the most advanced ones, requires personnel with lots practical transportation planning experience and with high level of education and training. In this paper we propose a comprehensive framework for an Intelligent Decision Support System (IDSS) for Traffic Congestion Management System that utilizes a state of the art transportation network equilibrium modeling and providing an easy to use GIS-based interaction environment. The developed IDSS reduces the dependability on the expertise and level of education of the transportation planners, transportation engineers, or any transportation decision makers. 展开更多
关键词 Traffic CONGESTION MANAGEMENT SYSTEM TRANSPORTATION SYSTEM MANAGEMENT INTELLIGENT decision support SYSTEM Urban TRANSPORTATION Systems analysis MULTICLASS Simultaneous TRANSPORTATION Equilibrium Models INTELLIGENT Scenario Creation Assistance Agent
在线阅读 下载PDF
言语想象脑电解码及神经可解释性研究
9
作者 税睿 赵瑞 张军鹏 《神经解剖学杂志》 北大核心 2026年第1期24-32,共9页
目的:为提升非侵入式脑机接口中言语想象任务的解码精度,本研究构建了一套基于多任务语言范式的脑电信号(EEG)识别框架。方法:采用公开发布的高密度言语想象EEG数据集。针对信号维度高与噪声干扰强的问题,分别在时域利用主成分分析(PCA... 目的:为提升非侵入式脑机接口中言语想象任务的解码精度,本研究构建了一套基于多任务语言范式的脑电信号(EEG)识别框架。方法:采用公开发布的高密度言语想象EEG数据集。针对信号维度高与噪声干扰强的问题,分别在时域利用主成分分析(PCA)进行特征降维,在频域采用共空间模式(CSP)提取判别性特征,并结合支持向量机(SVM)、随机森林(RF)与多层感知机(MLP)开展分类建模。结果:PCA-SVM组合在时域平均准确率达99%,CSP结合机器学习分类器在频域识别性能亦达到99%。结论:基于SHAP的可解释性分析揭示前额极及Broca区在语言加工中的主导作用。结果表明,该方法在复杂任务结构下具备较高的解码鲁棒性和良好的神经可解释性,为后续语言型脑机接口(BCI)系统和脑电语义建模相关研究提供方法学参考。 展开更多
关键词 脑电信号 脑机接口 支持向量机 主成分分析 共空间模式 言语解码
原文传递
基于OCSVM的行业负荷特征异常辨识方法
10
作者 陈光宇 杨光 +3 位作者 施蔚锦 蔡鑫灿 陈婉清 刘昊 《电力工程技术》 北大核心 2026年第2期70-79,共10页
为解决近年来用户行业变化特性加剧导致的难以准确辨识用户档案信息变动的问题,文中提出一种基于数据驱动的负荷特征异常辨识方法。首先,提出一种两阶段行业典型负荷形态构建方法,利用基于层次密度的含噪声应用空间聚类(hierarchical de... 为解决近年来用户行业变化特性加剧导致的难以准确辨识用户档案信息变动的问题,文中提出一种基于数据驱动的负荷特征异常辨识方法。首先,提出一种两阶段行业典型负荷形态构建方法,利用基于层次密度的含噪声应用空间聚类(hierarchical density-based spatial clustering of applications with noise,HDBSCAN)提取用户在不同场景下的典型日负荷曲线,并利用改进的K-means算法对提取出的典型日负荷曲线进行聚类分析,构建行业的典型负荷形态;其次,提出一种多维场景负荷特征异常智能研判方法,通过构造用户的负荷特征,使用熵权法评估行业典型场景的相对重要性,并采用单分类支持向量机(one-class support vector machine,OCSVM)算法量化每个场景下的用户负荷特征的异常程度,通过加权计算得到用户的综合嫌疑得分并排序,从而实现对负荷特征异常用户的准确辨识。最后,采用某地区实际用户数据进行算例验证。仿真结果表明,所提方法在行业典型负荷场景构建及负荷特征异常辨识方面表现出良好的可行性与实用价值。 展开更多
关键词 数据驱动 负荷特征异常 基于层次密度的含噪声应用空间聚类(HDBSCAN)-改进K-means算法 多维场景分析 单分类支持向量机(OCSVM) 综合嫌疑得分
在线阅读 下载PDF
河南省县域城镇发展支撑力时空演变及提升机理分析
11
作者 史焱文 郭桐桐 程智韬 《资源开发与市场》 2026年第2期229-236,共8页
党的十八大以来,针对新型城镇化建设,国家制定出台了一系列改革举措,加快推进了以县城为重要载体的城镇化。利用河南省103个县域样本数据,通过熵权法、线性加权法、空间自相关分析法及地理加权回归模型,揭示了2015年、2020年、2023年县... 党的十八大以来,针对新型城镇化建设,国家制定出台了一系列改革举措,加快推进了以县城为重要载体的城镇化。利用河南省103个县域样本数据,通过熵权法、线性加权法、空间自相关分析法及地理加权回归模型,揭示了2015年、2020年、2023年县域城镇发展支撑力水平的时空演变特征。结果表明:(1)2015—2023年,河南省县域城镇发展支撑力水平显著提升,整体得分增幅达77.4%,其中,受“百城建设提质工程”政策影响,2015—2020年均增速为11.8%;2020年以后增速放缓至0.58%。县域城镇发展支撑力存在显著的空间分异特征,表现为“南高北低、东强西弱”的格局;(2)河南省县域城镇发展支撑力的空间集聚效应逐年增强,全局莫兰指数从2015年的0.094增至2023年的0.408;(3)城镇化水平、常住人口和教育支出对县域城镇发展支撑力的影响呈现显著时空变化,其中城镇化效应逐步由“核心-边缘”结构转向郑州都市圈的辐射带动模式,人口集聚与教育支出对城镇发展支撑力的提升作用不断增强。 展开更多
关键词 县域城镇发展支撑力 时空演变 空间自相关分析 地理加权回归模型 河南省
在线阅读 下载PDF
Gap analysis in decision support systems for real-estate in the era of the digital earth
12
作者 Hamidreza Rabiei-Dastjerdi Gavin McArdle +1 位作者 Stephen A.Matthews Peter Keenan 《International Journal of Digital Earth》 SCIE 2021年第1期121-138,共18页
Searching for a property is inherently a multicriteria spatial decision.The decision is primarily based on three high-level criteria composed of household needs,building facilities,and location characteristics.Locatio... Searching for a property is inherently a multicriteria spatial decision.The decision is primarily based on three high-level criteria composed of household needs,building facilities,and location characteristics.Location choice is driven by diverse characteristics;including but not limited to environmental factors,access,services,and the socioeconomic status of a neighbourhood.This article aims to identify the gap between theory and practice in presenting information on location choice by using a gap analysis methodology through the development of a sevenfactor classification tool and an assessment of international property websites.Despite the availability of digital earth data,the results suggest that real-estate websites are poor at providing sufficient location information to support efficient spatial decision making.Based on a case study in Dublin,Ireland,we find that although neighbourhood digital earth data may be readily available to support decision making,the gap persists.We hypothesise that the reason is two-fold.Firstly,there is a technical challenge to transform location data into usable information.Secondly,the market may not wish to provide location information which can be perceived as negative.We conclude this article with a discussion of critical issues necessary for designing a spatial decision support system for real-estate decision making. 展开更多
关键词 Gap analysis digital earth spatial decision support systems(SDSS) spatial data real-estate DUBLIN
原文传递
长距离隧洞施工过程中渗透孔压演化规律研究
13
作者 苏凯 龚仁煌 +2 位作者 魏元基 王盟 董斌 《中国农村水利水电》 北大核心 2025年第8期165-170,176,共7页
依托某长距离供水隧洞工程实际,建立三维有限元渗流数值分析模型,考虑隧洞开挖和支护过程中的动态特性,研究隧洞施工期的渗透孔压演化规律。隧洞开挖过程中孔压的时空演化曲线可以分为3个阶段:缓慢变化阶段、急剧变化阶段和逐渐稳定阶... 依托某长距离供水隧洞工程实际,建立三维有限元渗流数值分析模型,考虑隧洞开挖和支护过程中的动态特性,研究隧洞施工期的渗透孔压演化规律。隧洞开挖过程中孔压的时空演化曲线可以分为3个阶段:缓慢变化阶段、急剧变化阶段和逐渐稳定阶段。同时依托隧洞施工开挖期掌子面逐步推进及衬砌管片安装支护(含豆砾石回填与灌浆等)过程中孔压的时空演化特征,探讨了隧洞开挖过程中的渗流场扰动范围。结果表明:在隧洞尚未开挖到监测断面时,洞周孔压已经开始变化,且在监测断面附近约5πD(D为隧洞直径)范围内,洞周孔压开始发生剧烈变化,而管片拼装支护对洞周孔压的影响范围略小,约为3πD,且其影响具有一定的滞后性;基于瞬态渗流计算模式的平面模型,可以提供三维计算模型中某施工环节(开挖或支护)完成后对应稳定时刻的计算结果,但无法模拟孔压的时空演化过程。 展开更多
关键词 TBM隧洞 渗透孔压 数值分析 衬砌支护 时空效应
在线阅读 下载PDF
“平急两用”视角下北京“二绿”地区蓄滞洪与游憩潜力空间特征评价与权衡协同关系
14
作者 林辰松 王润芝 +2 位作者 陈泓宇 吴龙峰 邵明 《北京林业大学学报》 北大核心 2025年第11期127-136,共10页
【目的】在城镇雨洪风险加剧与国家倡导“平急两用”公共基础设施的背景下,探究蓄滞洪区的多功能复合利用与空间效率提升路径至关重要。为此,本研究旨在构建一套兼顾蓄滞洪与游憩潜力的空间评价方法,定量揭示其权衡协同关系,以期为“平... 【目的】在城镇雨洪风险加剧与国家倡导“平急两用”公共基础设施的背景下,探究蓄滞洪区的多功能复合利用与空间效率提升路径至关重要。为此,本研究旨在构建一套兼顾蓄滞洪与游憩潜力的空间评价方法,定量揭示其权衡协同关系,以期为“平急两用”理念下蓄滞洪区的空间规划与精准配置提供科学依据。【方法】以北京市第二道绿化隔离地区(“二绿”地区)为研究对象,耦合多准则决策分析(MCDA)与地理信息系统(GIS)方法,构建蓄滞洪与游憩双重潜力评价指标体系。并采用熵权法客观赋权,通过GIS空间加权叠加分析两类潜力的空间分布特征;进而运用双变量空间自相关分析法,定量辨识两类潜力在空间上的权衡协同格局。【结果】(1)蓄滞洪潜力整体呈“西北-西南-东南高,东北低”的分布格局,高潜力区主要分布于西部丘陵、西南部及东部低洼河网地带。(2)游憩潜力整体表现为“中心高,外围低,局部斑块突出”的分布格局,高潜力区集中于西部山地、东北部湿地及南部关键节点。(3)两类潜力在空间上以权衡关系为主导,协同区域有限。具体而言,蓄滞洪与游憩潜力双高协同区分布于西部山前地带与东部湿地,蓄滞洪潜力高-游憩潜力低权衡区集中于西南与东南部的低洼河网区,蓄滞洪潜力低-游憩潜力高权衡区主要位于临近中心的城镇化区域,蓄滞洪与游憩潜力双低区则零散分布于建设用地与主要交通廊道周边。【结论】本研究构建了适用于“平急两用”场景的蓄滞洪与游憩潜力综合评价指标体系,明晰了二者的权衡协同关系及其空间分异特征,并据此提出了针对不同功能组合区的差异化优化策略。研究成果将为“平急两用”型蓄滞洪区的空间识别、分区管控及协同优化提供理论框架与决策支持。 展开更多
关键词 “平急两用” 蓄滞洪区 空间特征评价 权衡协同 MCDA-GIS耦合 多准则决策分析 空间规划协同优化
在线阅读 下载PDF
河南省心理援助热线首次来电且有自杀意念者的特征分析
15
作者 刘坤亚 李小妞 +6 位作者 张清清 张磊 成绘平 王诗韵 侯运生 许颖 张瑞岭 《中国心理卫生杂志》 北大核心 2025年第5期398-404,共7页
目的:探讨河南省心理援助热线中,首次来电且有自杀意念者的时空分布特征及自杀意念的相关危险因素。方法:使用河南省心理援助热线电脑咨询操作系统,提取2020年1月-2023年10月期间拨打该热线的31401例来电者的资料。采用圆形分布和核密... 目的:探讨河南省心理援助热线中,首次来电且有自杀意念者的时空分布特征及自杀意念的相关危险因素。方法:使用河南省心理援助热线电脑咨询操作系统,提取2020年1月-2023年10月期间拨打该热线的31401例来电者的资料。采用圆形分布和核密度分析法探讨首次来电且有自杀意念者的时空分布;采用二元logistic回归分析探讨自杀意念的危险因素。结果:共纳入5494例首次来电,其中1697例(30.9%)报告近2周有自杀意念。时间分布上,自杀意念来电高峰时段为12:36~01:08,且星期分布显示周五来电量最多;空间分布上,有自杀意念来电者的主中心呈现以郑州市和新乡市为核心的联合集聚特征,次中心在省内呈现多中心离散分布特征。Logistic回归分析显示,年龄<20岁(OR=11.85)、无业(OR=1.78)、有精神心理问题(OR=5.03)、有家庭关系问题(OR=3.67)、经济困难(OR=7.08)是自杀意念的危险因素。结论:河南省心理援助热线自杀意念者来电时间分布有集中趋势,来电空间分布有不均衡性;在接听首次有自杀意念者的来电时,应重点关注年龄<20岁、无业、有精神心理问题、有家庭关系问题及经济困难的来电者。 展开更多
关键词 心理援助热线 自杀意念 圆形分布法 核密度分析法 时空分布 危险因素
在线阅读 下载PDF
某大跨度拱形空间钢结构体系选型分析与设计 被引量:1
16
作者 钱骏巍 梁汝鸣 +5 位作者 葛序尧 和西良 刘洋 张波 庞振 张洪达 《建筑结构》 北大核心 2025年第22期82-88,共7页
黄海之眼大跨度拱形观光桥项目主体结构为拱形空间钢结构。针对结构跨度大、筒轴平面外刚度较小等特点,基于结构竖向挠度、平面外位移等因素,对空间编织网格体系及空间径环支撑筒壳体系进行方案比选。同时对结构进行了屈曲分析、风荷载... 黄海之眼大跨度拱形观光桥项目主体结构为拱形空间钢结构。针对结构跨度大、筒轴平面外刚度较小等特点,基于结构竖向挠度、平面外位移等因素,对空间编织网格体系及空间径环支撑筒壳体系进行方案比选。同时对结构进行了屈曲分析、风荷载作用下的弹性分析、多遇地震弹性分析、罕遇地震弹塑性分析。结果表明:空间径环支撑筒壳体系的抗侧能力优于空间编织网格体系;在结构弹性工作阶段,结构动力特性及位移均满足规范要求;在考虑了结构初始缺陷及几何非线性、材料非线性的条件下,结构整体构件屈曲系数较大,结构具有良好的整体稳定性和足够的安全储备;结构在罕遇地震作用下抗震性能良好,所有杆件均处于弹性工作状态,满足抗震要求。 展开更多
关键词 大跨结构 拱形空间钢结构 空间编织网格体系 空间径环支撑筒壳体系 选型分析 屈曲分析 抗震性能
在线阅读 下载PDF
“精确”假象与可靠决策:土壤污染调查数据的描述性统计与地统计插值稳定性对比研究
17
作者 陈樯 杨璐 +4 位作者 盛峰 祝欣 张晓东 芦圆圆 龙涛 《生态与农村环境学报》 北大核心 2025年第11期1431-1440,共10页
工业场地土壤污染精准评估是风险管控与修复决策的基础。当前实践中,地统计插值方法因能提供直观污染分布图而得到高度重视,但其结果受采样策略的影响大,稳定性存疑。本研究基于同一工业场地的两次独立调查数据,针对砷污染,系统比较了... 工业场地土壤污染精准评估是风险管控与修复决策的基础。当前实践中,地统计插值方法因能提供直观污染分布图而得到高度重视,但其结果受采样策略的影响大,稳定性存疑。本研究基于同一工业场地的两次独立调查数据,针对砷污染,系统比较了数值统计分析与空间格局表征结果的稳定性差异。分析表明:关键统计量如均值95%置信上限、中位数和95%分位数表现出较高稳定性,尤其是均值95%置信上限相对偏差<5%,适用于风险决策;克里金插值结果稳定性较差,污染羽边界、热点位置和超标面积估算变异显著,尤其是在空间自相关性弱的情况下,插值结果更多地反映了采样点分布而非真实污染格局。本研究提出,过度依赖单一的地统计插值结果可能存在决策风险,建议构建以稳健统计量为核心、辅以空间趋势可视化及不确定性识别的综合评估框架。本研究为提升污染场地评估结果可靠性与决策科学性提供了重要依据,对场地调查技术的发展具有实践指导意义。 展开更多
关键词 土壤污染评估 统计分析 地统计插值 稳定性 决策框架
在线阅读 下载PDF
新质生产力赋能应急物资保障效能测度与空间集聚研究
18
作者 米俊 董丹琪 王迪 《灾害学》 北大核心 2025年第3期14-20,共7页
应急物资保障是国家应急管理体系建设的重要内容,新质生产力为应急管理体系和能力现代化建设提供强力支撑。该文运用数据包络分析的规模报酬可变模型和空间自相关模型,测度分析我国30个省级行政区的应急物资保障效能及其空间集聚特征。... 应急物资保障是国家应急管理体系建设的重要内容,新质生产力为应急管理体系和能力现代化建设提供强力支撑。该文运用数据包络分析的规模报酬可变模型和空间自相关模型,测度分析我国30个省级行政区的应急物资保障效能及其空间集聚特征。研究发现:(1)2011—2022年,我国应急物资保障效能整体提升,区域呈现“东部高,中西部低”的特征,但“中部崛起”战略和“一带一路”倡议使中西部地区应急物资保障效能明显提高。(2)应急物资保障效能的空间集聚特征为“东高中西低”,山东、江苏等东部地区位于高-高(HH)象限,新疆、内蒙古等中西部地区位于低-低(LL)象限。研究丰富了新质生产力发展促进高水平安全的相关内容。 展开更多
关键词 新质生产力 应急物资保障效能 数据包络分析 空间集聚
在线阅读 下载PDF
深厚软土地区小尺寸工作井基坑支护结构设计优化分析
19
作者 王高科 陈建伟 周榕辉 《隧道建设(中英文)》 北大核心 2025年第S2期313-325,共13页
为探明深厚软土地区小尺寸工作井空间效应的影响,提升基坑支护结构设计及计算的合理性,以宁波市通途路盾构法综合管廊工程沿线31座小尺寸工作井深基坑为研究对象,首先,基于基坑几何尺寸、基坑支护结构参数等详细统计数据,系统分析此类... 为探明深厚软土地区小尺寸工作井空间效应的影响,提升基坑支护结构设计及计算的合理性,以宁波市通途路盾构法综合管廊工程沿线31座小尺寸工作井深基坑为研究对象,首先,基于基坑几何尺寸、基坑支护结构参数等详细统计数据,系统分析此类基坑的设计现状;然后,采用理论分析与三维有限元模拟相结合的方法,深入研究典型深厚软土地层下小尺寸工作井基坑施工全过程的变形特性;最后,通过建立包含不同基坑长边尺寸的一系列计算模型,定量揭示空间效应的分布规律及其影响范围,并提出小尺寸工作井基坑支护设计的优化策略。研究结果表明:1)盾构法综合管廊工作井属于典型的小尺寸深基坑工程,在深厚软土地区此类基坑空间效应明显,现有基坑支护结构设计存在优化潜力。2)当基坑长边<25 m时,支护参数优化范围可取为基坑长边、短边全长;当基坑长边≥25 m时,支护参数优化范围可缩减为长边两端各l/3(l为基坑长边)区域及短边全长。3)小尺寸工作井基坑支护结构变形控制的关键在于合理设计地下连续墙厚度,稳定性控制的关键在于足够的地下连续墙插入比。 展开更多
关键词 深厚软土地区 小尺寸深基坑 支护结构 空间效应 数值分析
在线阅读 下载PDF
Improvement of classification accuracy of functional near-infrared spectroscopy signals for hand motion and motor imagery using a common spatial pattern algorithm
20
作者 Omid Asadi Mahsan Hajihosseini +2 位作者 Sima Shirzadi Zahra Einalou Mehrdad Dadgostar 《Intelligent Medicine》 2025年第2期123-131,共9页
Objective Classifying motor imagery tasks via functional near-infrared spectroscopy(fNIRS)poses a significant challenge in brain-computer interface(BCI)research due to the high-dimensional nature of the signals.This s... Objective Classifying motor imagery tasks via functional near-infrared spectroscopy(fNIRS)poses a significant challenge in brain-computer interface(BCI)research due to the high-dimensional nature of the signals.This study aimed to address this challenge by employing the common spatial pattern(CSP)algorithm to reduce input dimensions for support vector machine(SVM)and linear discriminant analysis(LDA)classifiers.Methods Data were collected from 15 healthy right-handed volunteers performing tasks involving left-hand motion,left-hand motor imagery,right-hand motion,and right-hand motor imagery.Signals from 20-channel fNIRS were utilized,with input features including statistical descriptors such as mean,variance,slope,skewness,and kurtosis.The CSP algorithm was integrated into both SVM and LDA classifiers to reduce dimensionality.The main statistical methods included classification accuracy assessment and comparison.Results Mean and slope were found to be the most discriminative features.Without CSP,SVM and LDA classifiers achieved average accuracies of 59.81%±0.97%and 69%±11.42%,respectively.However,with CSP integration,accuracies significantly improved to 81.63%±0.99%and 84.19%±3.18%for SVM and LDA,respectively.This value represents an increase of 21.82%and 15.19%in accuracy for SVM and LDA classifiers,respectively.Dimensionality reduction from 100 to 25 dimensions was achieved for SVM,leading to reduced computational complexity and faster calculation times.Additionally,the CSP technique enhanced LDA classifier accuracy by 3.31%for both motion and motor imagery tasks.Conclusion Integration of the CSP algorithm may demonstrate promising potential for improving BCI systems'performance. 展开更多
关键词 Functional near-infrared spectroscopy Common spatial pattern Motor imagery support vector machine Linear discriminant analysis Sequential forward selection
原文传递
上一页 1 2 10 下一页 到第
使用帮助 返回顶部