期刊文献+
共找到376篇文章
< 1 2 19 >
每页显示 20 50 100
Seismic hazard level reduction for existing buildings considering remaining building lifespans 被引量:1
1
作者 Ji-Hun Park 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2019年第3期649-661,共13页
Seismic hazard levels lower than those for design of new buildings have been permitted for seismic evaluation and retrofi t of existing buildings due to the relatively short remaining lifespans. The seismic hazard red... Seismic hazard levels lower than those for design of new buildings have been permitted for seismic evaluation and retrofi t of existing buildings due to the relatively short remaining lifespans. The seismic hazard reduction enables costeff ective seismic evaluation and retrofi t of existing buildings with limited structural capacity. The current study proposes seismic hazard reduction factors for Korea, one of low to moderate seismicity regions. The seismic hazard reduction factors are based on equal probabilities of non-exceedance within diff erent remaining building lifespans. A validation procedure is proposed to investigate equality of seismic risk in terms of ductility-based limit states using seismic fragility assessment of nonlinear SDOF systems, of which retrofi t demands are determined by the displacement coeffi cient method of ASCE 41-13 for diff erent target remaining building lifespans and corresponding reduced design earthquakes. Validation result shows that the use of seismic hazard reduction factors can be permitted in conjunction with appropriate lower bounds of the remaining building lifespans. 展开更多
关键词 SEISMIC hazard level existing BUILDING REMAINING BUILDING LIFESPAN probability of LIMIT state
在线阅读 下载PDF
Multi-scale monitoring for hazard level classification of brown planthopper damage in rice using hyperspectral technique
2
作者 Juan Liao Wanyan Tao +8 位作者 Yexiong Liang Xinying He Hui Wang Haoqiu Zeng Zaiman Wang Xiwen Luo Jun Sun Pei Wang Ying Zang 《International Journal of Agricultural and Biological Engineering》 2024年第6期202-211,共10页
The primary aim of this study was to classify the hazard level of brown planthopper(BPH)damage in rice.Three datasets,including spectral reflectance corresponding to the sensitive wavelengths from rice canopy spectral... The primary aim of this study was to classify the hazard level of brown planthopper(BPH)damage in rice.Three datasets,including spectral reflectance corresponding to the sensitive wavelengths from rice canopy spectral wavelengths,rice stem spectral wavelengths,and fusion information of rice canopy and stem spectral wavelengths were used for BPH hazard level classification by using different algorithms.Datasets and algorithms were optimized by the BPH hazard level classification effects(which was evaluated by indices of accuracy,precision,recall,F_(1),and k-value).The optimized algorithm combination was used to build a hazard level classification model for spectral reflectance corresponding to the sensitive wavelength from the rice canopy spectral images.Results showed that:(1)The spectral reflectance corresponding to the sensitive wavelengths of fusion information dataset performed best in BPH hazard level classification,with the highest accuracy(99.08%),precision(99.31%),recall(98.83%),F_(1)(0.99),and k-value(0.99).(2)The optimum algorithm combination was Savitzky-Golay(S-G)smoothing,principal component analysis(PCA)for sensitive wavelength selection,and broad-learning system(BLS)for modeling.(3)The spectral reflectance corresponding to the sensitive wavelengths dataset of rice canopy spectral images achieved accuracy(80.63%),precision(80.28%),recall(77.03%),F_(1)(0.79),and k-value(0.74)in classifying BPH hazard level by using the optimum algorithm combination. 展开更多
关键词 brown planthopper(BPH) hazard level classification hyperspectral technique rice canopy rice stem fusion information
原文传递
The Main Biological Hazards in Animal Biosafety Level 2 Facilities and Strategies for Control 被引量:4
3
作者 LI Xiao Yan XUE Kang Ning +1 位作者 JIANG Jin Sheng LU Xuan Cheng 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2016年第4期300-304,共5页
Concern about the biological hazards involved in microbiological research, especially research involving laboratory animals, has increased in recent years. Working in an animal biosafety level 2 facility (ABSL-2), c... Concern about the biological hazards involved in microbiological research, especially research involving laboratory animals, has increased in recent years. Working in an animal biosafety level 2 facility (ABSL-2), commonly used for research on infectious diseases, poses various biological hazards. Here, the regulations and standards related to laboratory biosafety in China are introduced, the potential biological hazards present in ABSL-2 facilities are analyzed, and a series of strategies to control the hazards are presented. 展开更多
关键词 The Main Biological hazards in Animal Biosafety level 2 Facilities and Strategies for Control
暂未订购
安阳市内黄县外来入侵植物的调查研究 被引量:3
4
作者 朱秀红 周琳坡 +4 位作者 刘宇凡 张龙冲 孙合祥 孙翱杰 茹广欣 《河南农业大学学报》 北大核心 2025年第1期68-78,共11页
【目的】明确安阳市内黄县外来植物的入侵现状,以期为外来植物入侵防控、生物多样性保护与生态安全管理提供依据。【方法】通过对内黄县17个乡镇168个位点开展实地调查,获取该地区外来入侵植物本底,并分析各入侵植物的生长状况;筛选出... 【目的】明确安阳市内黄县外来植物的入侵现状,以期为外来植物入侵防控、生物多样性保护与生态安全管理提供依据。【方法】通过对内黄县17个乡镇168个位点开展实地调查,获取该地区外来入侵植物本底,并分析各入侵植物的生长状况;筛选出外来入侵植物风险评估指标,形成风险评估体系,并对所有指标进行赋值,评估每一种外来植物的入侵风险。【结果】共计发现外来入侵植物44种,隶属于16科,菊科有15个物种,所占比例为34%;从地理起源上分,有5种类型,其中来自美洲的最多,有30种,所占比例为66.7%;生活型一共有7种,1 a生草本物种最多,为32种,所占比例为71.1%;Ⅰ级危害等级的外来入侵植物有3种,分别为小蓬草(小白酒草)(Erigeron canadensis L.)、牵牛(Ipomoea nil(L.)Roth)和黑麦草(Lolium perenne L.);Ⅱ级危害等级有6种,Ⅲ级危害有9种;Ⅳ级危害有8种;Ⅴ级危害有18种。【结论】须加强对外来入侵植物的管控。内黄县的外来植物侵害情况研究报告和入侵危害评价数据,对于当地以及其他地区制定管理策略、有效控制外来植物入侵具有一定借鉴价值。 展开更多
关键词 外来入侵植物 风险评估 危害等级 内黄县
在线阅读 下载PDF
Case Study on Identification of Flood Hazard in the Lower Catchment Area of the Attanagalu Oya River Basin 被引量:1
5
作者 Kithulgasmulle Lekamlage Nadeeka Chathurani Hatanpola Acharilage Sampath Arunashantha +2 位作者 Bamunu Arachchilage Sumanajith Kumara Pattinaya Marakkala Udara Idunil Thilakarathna Gargi Arachchilage Anudi Nishika Kaushalya 《Journal of Geoscience and Environment Protection》 2022年第7期305-318,共14页
The present work aims to identify flood hazards and risks, particularly to the Attanagalu Oya river basin in Gampaha district, the western province in Sri Lanka. Attanagalu Oya river catchment area periodically faced ... The present work aims to identify flood hazards and risks, particularly to the Attanagalu Oya river basin in Gampaha district, the western province in Sri Lanka. Attanagalu Oya river catchment area periodically faced flood hazards. The flood is categorized by complex like 2008, 2010, 2016, 2017, and it chose 2016 as the primary flood event. Study areas have been selected depending on data availability. Attanagalu Oya river basin is mainly focused as a study area. However, here selected only four Grama Niladhari Divisions are as a sample area. Those are;Kirindivita, Ambanvita, Thammita West, Gonagaha1. Furthermore, many flood hazards can be identified when considering the flood events history. But here selected only two years were 2010 and 2016. These two years were selected with high flood events. For the study, that flood series used 1 feet elevation contours used to identify flood levels and used LiDAR image to identify risk areas in the study site. Due to the blockage of the main waterways that discharge water into the Negombo Lagoon, limited water transportation, low lying land reclamation for development, mainly affect paddy lands and roads, and flood as a major problem identified temporarily and spatially. Eventually, the study could identify flood-prone areas and map the risk zones within the study area. 展开更多
关键词 Flood hazards GIS and RS Attanagalu Oya Risk levels
在线阅读 下载PDF
Methodological study of coastal geological hazard assessment based on GIS 被引量:1
6
作者 LIU Jun CHENG Jian-mei JIANG Fang-yuan 《Journal of Groundwater Science and Engineering》 2015年第1期77-85,共9页
The current researches on risk assessment of geological disasters mainly focus on unexpected disasters such as collapses, landslides and mud-rock flows etc. As the convergence zone of land and sea, coastal zone is the... The current researches on risk assessment of geological disasters mainly focus on unexpected disasters such as collapses, landslides and mud-rock flows etc. As the convergence zone of land and sea, coastal zone is the most active and complex area of interactions of lithosphere, hydrosphere, atmosphere, biosphere and anthroposphere. The ecological environment of coastal zone is very fragile, so further systematical research on coastal geological hazard assessment and prevention is in urgent need. The author begins with the definition and research contents and selects three typical coastal geological disasters, namely, the seawater intrusion, coastline change and sea-level rise as the objects of study. The systematic analysis and study on assessment system and methods are conducted, hazard assessment factors are selected, and a completely set of coastal disaster assessment system is established based on the technique of GIS. We took Bao’an District of Shenzhen City as an example and carried out a case study. 展开更多
关键词 Costal zone Geological hazard GIS Seawater intrusion Coastline change Sea-level rise
在线阅读 下载PDF
FORECAST OF IMPACTS OF SEA-LEVEL RISE ON THELOW COLONIZED ISLANDS AND THEIR SURROUNDING WATERS IN THE CHANGJIANG RIVER MOUTH
7
作者 YANG Shi-lun ZHAO Qing-ying +1 位作者 XIE Wen-hui WANG Xing-fang(State Key Laboratory of Estuarine & Coastal Research, East China Normal University, Shanghai 200062, P R. China) 《Chinese Geographical Science》 SCIE CSCD 2000年第2期113-118,共6页
As a worldwide authoritative, IPCC forecasted in 1990 that the world- s sea level would most probably rise by 0. 66 m by the end of the 21 st century. Combined with the local depression caused by the sink of the earth... As a worldwide authoritative, IPCC forecasted in 1990 that the world- s sea level would most probably rise by 0. 66 m by the end of the 21 st century. Combined with the local depression caused by the sink of the earth’s crust and the human activity, the relative sea level in the Chanaiiang River mouth will rise by about 1. 0 m during the same peried. Based on this figure, the article forecasted the impacts of sea-level rise on the safety coefficient of coastal structures and civil facilities, loss of wetlands, flood hazard as well as water intrusion. The results show that: 1 ) 40% as large as the present engil1eering mass should be added to the coastal structures in order to maintain the safety coefficient; 2 ) a dynamic loss of 60 km2 of wetlands, as much as 15% of the present total area, would be caused; 3) to hinder the increase inflood hazard dy11amic capacity to drain water must increase by at least 34 times as large as the present; 4) to maintain the present navigation conditions, about 100 million yuan (RMB) is needed to reconstruct over 30(X) bridges and 30 sluices;and 5 ) the disastrous salt water intrusion caused by the sea-level rise could be encountered by the increase in water discharge from the Three Gorge Reservoir in the dry season. 展开更多
关键词 SEA-level rise flood hazard loss of wetland salt water INTRUSION CHANGJIANG River MOUTH
在线阅读 下载PDF
基于指标信息融合的冲击地压危险等级预测
8
作者 乔美英 史有强 《煤矿安全》 北大核心 2025年第2期118-125,共8页
随着煤矿开采深度的增加,冲击地压频发,精准预测冲击地压危险等级对于煤矿安全开采至关重要,然而影响冲击地压的指标众多,且数据特性不同,针对单一算法无法满足不同指标要求的问题,提出了基于数据挖掘的指标信息融合模型预测方法。该模... 随着煤矿开采深度的增加,冲击地压频发,精准预测冲击地压危险等级对于煤矿安全开采至关重要,然而影响冲击地压的指标众多,且数据特性不同,针对单一算法无法满足不同指标要求的问题,提出了基于数据挖掘的指标信息融合模型预测方法。该模型由条件K近邻、加成随机森林和权重表决算法组成,首先将埋深指标输入条件K近邻算法,然后将其他指标输入加成随机森林算法,分别使用2种算法进行冲击地压危险等级预测,最后将2种算法的预测结果放入权重表决算法中进行表决,加权结果最大的危险等级即为最终危险等级。使用2010—2013年在千秋煤矿10个工作面采集的350条样本数据,进行数据挖掘与模型构建;使用2015—2016年在千秋煤矿4个工作面采集的20条样本数据进行实验验证。结果表明:基于数据挖掘的指标信息融合模型预测方法相比较于传统预测方法具有更高的预测准确性。 展开更多
关键词 数据挖掘 条件K近邻 加成随机森林 冲击地压 危险等级预警
在线阅读 下载PDF
辐射防护基本标准中应急照射情况及其防护
9
作者 张建岗 李国强 +4 位作者 杨亚鹏 冯宗洋 贾林胜 王宁 梁博宁 《辐射防护》 北大核心 2025年第S1期76-81,共6页
介绍了国际辐射防护与辐射源安全基本标准中应急照射情况的总体要求、应急管理体系、公众照射、应急人员照射、从应急照射情况向现存照射情况的转变等方面的要求,介绍了国际核与辐射应急准备和响应安全标准的变化,提出了修订我国辐射防... 介绍了国际辐射防护与辐射源安全基本标准中应急照射情况的总体要求、应急管理体系、公众照射、应急人员照射、从应急照射情况向现存照射情况的转变等方面的要求,介绍了国际核与辐射应急准备和响应安全标准的变化,提出了修订我国辐射防护基本标准的建议。 展开更多
关键词 辐射防护 基本标准 应急照射情况 核与辐射应急 参考水平 危害评价 防护策划 通用准则
在线阅读 下载PDF
The Land Subsidence and Relative Sea Level Rise in Chinese Delta Areas
10
作者 YeYincan LiuDujuan 《工程科学(英文版)》 2004年第3期36-41,共6页
Based on some experts’ research effort, the problems of land subsidence and relative sea level rise in three Chinese delta areas (Huanghe, Changjiang and Zhujiang Delta) are analyzed and discussed in this paper. The ... Based on some experts’ research effort, the problems of land subsidence and relative sea level rise in three Chinese delta areas (Huanghe, Changjiang and Zhujiang Delta) are analyzed and discussed in this paper. The authors’ opinion is that the land subsidence is mainly induced by human activity and has made the greater contributions to the relative sea level rise and become one of the geological hazards in these areas. In Tianjin and Shanghai areas where had ever existed serious land subsidence problem, due to the positive and effective control methods, the ratio of man-induced land subsidence to relative sea level rise decreased from 80%-90% in 1960s-1970s to less than 60% at present. But it is estimated that in the next tens of years this ratio will still be considerable. So human being must keep its eyes on this phenomenon and take more positive countermeasures to control the land subsidence. 展开更多
关键词 中国三角洲地区 相关海平面上升 地质危害 地面塌陷 全球环境变化 长江三角洲 珠江三角洲
在线阅读 下载PDF
地铁隧道致灾风险源及失稳破坏模式分析
11
作者 刘凯 刘绪壮 胡聪伟 《北方交通》 2025年第4期80-82,共3页
地铁隧道常发生涌水涌泥事故,涌水涌泥具有难预测、破坏性强的特点,既造成经济损失,也构成严重安全隐患。通过总结地铁隧道在施工和运营期间发生的涌水涌沙事故案例,对地铁隧道突涌水事故的致灾风险源、失稳破坏形式以及事故危害等级进... 地铁隧道常发生涌水涌泥事故,涌水涌泥具有难预测、破坏性强的特点,既造成经济损失,也构成严重安全隐患。通过总结地铁隧道在施工和运营期间发生的涌水涌沙事故案例,对地铁隧道突涌水事故的致灾风险源、失稳破坏形式以及事故危害等级进行划分和分析,为隧道涌水涌沙诱发机理研究和防治措施的设计提供参考依据。 展开更多
关键词 案例统计 致灾风险源 失稳破坏形式 危害等级
在线阅读 下载PDF
Exploring the Nexus between Climate Hazards and Conflict in Lamu County: Implications for Community Adaptation Action Plans
12
作者 Misiani Zachary Simeon Mwadiga +5 位作者 Mohamed Abubakar Hindada Boneya Onyango Linet Amos Okello Mohamed Rashid Dirie Monica Orero 《Journal of Environmental Protection》 2023年第12期984-1005,共22页
This paper investigated the complex relationship between climate change and security in Lamu County, with focus on community perceptions, vulnerabilities, and adaptation strategies. The study utilized a participatory ... This paper investigated the complex relationship between climate change and security in Lamu County, with focus on community perceptions, vulnerabilities, and adaptation strategies. The study utilized a participatory approach involving Focus Group Discussions (FGDs) and Key Informant Interviews (KIIs) to gather insights from diverse community members. Results revealed a growing recognition of climate change as a significant factor amplifying security risks, including resource-based conflicts, food and water insecurity, pest and disease outbreaks, and rising sea levels. The analysis of historical climate data indicated shifts in rainfall patterns and rising temperatures, exacerbating these hazards. Furthermore, it underscores the need to mainstream climate change actions across various sectors for sustainable development and human security. Lamu County in Kenya faces a myriad of security challenges stemming from climate change, with the community perceiving droughts, pests, diseases, and conflicts as prominent hazards. These climatic impacts have led to crop failures, livestock losses, water scarcity, property damage, displacement, and instability. Local adaptation strategies have shown varying degrees of effectiveness, highlighting the need for community-specific and sustainable solutions. The study identified local adaptation strategies and emphasized the importance of early warning systems, informed decision-making, and mainstreaming climate change actions across sectors to enhance human security and sustainable development. However, it also acknowledges limitations in community participation and suggests future research avenues to ensure the inclusion of marginalized voices in such studies. 展开更多
关键词 Kenya Climate Changes and Adaptation Pollution Climate hazards CONFLICT Security Temperature Rainfall Sea level Lamu County
在线阅读 下载PDF
Environmental problems in coastal zone of Chin──sea-level rise and groundwater table decline
13
作者 YU Jing-jie FU Guo-bin REN Hong-zun(Institute of Geography, Chinese Academy of Sciences, Beijing 100101, China) 《Journal of Geographical Sciences》 SCIE CSCD 1999年第3期307-312,共6页
This paper concerns two important environmental problems in China's coastal zone, i.e.,Sea Level Rise (SLR) and Groundwater Table Decline, as the response to climatic chanes/globalwarming due to greenhouse effect.... This paper concerns two important environmental problems in China's coastal zone, i.e.,Sea Level Rise (SLR) and Groundwater Table Decline, as the response to climatic chanes/globalwarming due to greenhouse effect. on the basis of possible twacts of these two problems on theregional natural, environmental and social systems, some response strategies were advised. 展开更多
关键词 sca-level rise coastal zone environmental problem land subsidence hazard
在线阅读 下载PDF
Level of education and mortality after radical prostatectomy 被引量:1
14
作者 Michael Froehner Rainer Koch +5 位作者 Stefan Propping Dorothea Liebeheim Matthias Hfibler Gustavo B Baretton Oliver W Hakenberg Manfred P Wirth 《Asian Journal of Andrology》 SCIE CAS CSCD 2017年第2期173-177,共5页
Estimating the risk of competing mortality is of importance in men with early prostate cancer to choose the most appropriate way of management and to avoid over- or under-treatment. In this study, we investigated the ... Estimating the risk of competing mortality is of importance in men with early prostate cancer to choose the most appropriate way of management and to avoid over- or under-treatment. In this study, we investigated the impact of the level of education in this context. The study sample consisted of 2630 patients with complete data on level of education (college, university degree, master craftsmen, comparable profession, or others), histopathological tumor stage (organ confined or extracapsular), lymph node status (negative or positive), and prostatectomy specimen Gleason score (〈7, 7, or 8-10) who underwent radical prostatectomy between 1992 and 2007. Overall, prostate cancer-specific, competing, and second cancer-related mortalities were study endpoints. Cox proportional hazard models for competing risks were used to study combined effects of the variables on these endpoints. A higher level of education was independently associated with decreased overall mortality after radical prostatectomy (hazard ratio [HR]: 0.75, 95% confidence interval [95% CI]: 0.62-0.91, P = 0.0037). The mortality difference was attributable to decreased second cancer mortality (HR: 0.59, 95% Ch 0.40-0.85, P = 0.0052) and noncancer mortality (HR: 0.73, 95% Ch 0.55-0.98, P = 0.0345) but not to differences in prostate cancer-specific mortality (HR: 1.16, 95% Ch 0.79-1.69, P = 0.4536 in the full model). In conclusion, the level of education might serve as an independent prognostic parameter supplementary to age, comorbidity, and smoking status to estimate the risk of competing mortality and to choose optimal treatment for men with early prostate cancer who are candidates for radical prostatectomy. 展开更多
关键词 COMORBIDITY competing risk analysis level of education life expectancy MORTALITY proportional hazards model prostate cancer radical prostatectomy SMOKING socioeconomic status
原文传递
海平面上升的灾害效应、风险评估及应对策略
15
作者 周健 于道德 +4 位作者 李琼 朱现晔 李莉 杨韫琪 吴志宏 《海洋科学》 北大核心 2025年第2期67-80,共14页
海平面上升是一种全球性、缓发性的海洋灾害,其广泛和深入的影响对人类社会发展带来严重挑战,受到学界普遍关注,但当前研究普遍存在灾害效应分析孤立割裂、风险评估体系差异明显、防范应对存在局限等问题。基于此,本文通过归纳梳理国内... 海平面上升是一种全球性、缓发性的海洋灾害,其广泛和深入的影响对人类社会发展带来严重挑战,受到学界普遍关注,但当前研究普遍存在灾害效应分析孤立割裂、风险评估体系差异明显、防范应对存在局限等问题。基于此,本文通过归纳梳理国内外海平面上升相关文献资料,系统总结了海平面上升所诱发的风暴潮增水、海岸侵蚀、海水/咸潮入侵、湿地退化等不同类型灾害效应及其机制的研究成果,并从灾害管理角度阐述了海平面上升风险评估、应对策略的研究现状与前沿动态,最后展望了未来研究趋向。未来研究应在健全完善调查监测体系的基础上,推进海平面上升影响综合研究及量化评价,总结凝练经典研究范式,推进灾害链式协同防治,强化动态风险预测评估,提升滨海地区适应气候变化扰动的韧性,推进海平面上升应对与管理能力现代化。 展开更多
关键词 海平面上升 灾害效应 风险评估 灾害管理 应对策略
在线阅读 下载PDF
未来土地利用变化情景下重庆市高温灾害的暴露度分析
16
作者 张静 牟凤云 楚昌全 《重庆师范大学学报(自然科学版)》 北大核心 2025年第1期83-96,共14页
明确重庆市在SSP2-4.5、SSP5-8.5等2种升温情景和惯性发展优先、经济发展优先、可持续发展优先等3种发展情景下的高温暴露度,为当地城市规划和灾害风险管理提供决策支持。基于2020年的重庆市土地利用数据,运用PLUS模型预测了2030年重庆... 明确重庆市在SSP2-4.5、SSP5-8.5等2种升温情景和惯性发展优先、经济发展优先、可持续发展优先等3种发展情景下的高温暴露度,为当地城市规划和灾害风险管理提供决策支持。基于2020年的重庆市土地利用数据,运用PLUS模型预测了2030年重庆市土地利用状况,并结合重庆市未来人口和日最高气温数据构建了综合暴露度模型。结果表明:1)SSP2-4.5情景下2030年重庆市主城都市区及渝东北三峡库区城镇群的南部高温致灾危险性较高;而SSP5-8.5情景下高温致灾危险性程度不同的区域从西到东呈带状分布,所对应的高温致灾危险性指数先减小后增大,其中高温致灾危险性较高区域的分布与在SSP2-4.5情景下的分布相似;2)2种升温情景下2030年重庆市耕地与林地的暴露度高于灌木、草地、水域、裸地和建设用地的暴露度;3)2种升温情景下2030年重庆市人口暴露度的空间分布具有一致性;4)2030年重庆市综合暴露度较高的区域主要集中分布在人口密集、经济相对发达地区以及以林地为主的区域。上述结果可为重庆市在未来城市建设发展中对土地利用的合理规划和针对易发生高温灾害的地区制定长期有效的防护措施提供参考。 展开更多
关键词 土地利用变化 高温灾害 暴露度 情景模拟 重庆市
原文传递
基于Stacking集成学习的隧道突水危险预测模型 被引量:1
17
作者 卢佳乐 张念 +1 位作者 牛萌萌 万飞 《中国安全科学学报》 北大核心 2025年第4期137-144,共8页
为解决机器学习在隧道突水危险智能预测领域存在的模型较单一和预测精度不够理想等问题,提出一种基于Stacking集成学习方法的预测模型。首先,通过搜集95条隧道共计232组隧道突水灾害数据建立隧道突水灾害数据集,并进行数据预处理;然后,... 为解决机器学习在隧道突水危险智能预测领域存在的模型较单一和预测精度不够理想等问题,提出一种基于Stacking集成学习方法的预测模型。首先,通过搜集95条隧道共计232组隧道突水灾害数据建立隧道突水灾害数据集,并进行数据预处理;然后,选取3种基学习器和2种元学习器以不同组合方式训练出8组Stacking集成模型,并筛选出6组较优的集成模型;最后,使用网格搜索调参并结合5折交叉验证超参数调优模型,对比分析6组参数调优后的Stacking集成模型的预测结果,选择出最优Stacking集成模型。结果表明:采用Stacking集成学习方法改进最优单模型支持向量机(SVM)后得到SVM+朴素贝叶斯(NB)+线性回归(LR)集成模型,其精确率、召回率和F_(1)分数分别达到0.94、0.91和0.92,整体预测效果优于其他对比模型,可准确预测隧道突水危险等级。 展开更多
关键词 Stacking集成学习 隧道突水 预测模型 危险等级 机器学习
原文传递
大坡降短沟道泥石流发育特征与危险性评价
18
作者 刘云鹏 沈程文 +2 位作者 肖华波 常鸣 李林泽 《地下空间与工程学报》 北大核心 2025年第S1期502-513,共12页
川西南高中山地貌区受到构造侵蚀剥蚀影响,河流两岸地形切割强烈、山高坡陡、沟谷纵横,泥石流沟发育,类型多样。其中一类泥石流尽管流域面积不大,且沟道短,但由于其坡降大,泥石流发生后,其势能较大,其影响范围具有很大不确定性,给防治... 川西南高中山地貌区受到构造侵蚀剥蚀影响,河流两岸地形切割强烈、山高坡陡、沟谷纵横,泥石流沟发育,类型多样。其中一类泥石流尽管流域面积不大,且沟道短,但由于其坡降大,泥石流发生后,其势能较大,其影响范围具有很大不确定性,给防治工作带来很大难度,对人民群众生命财产和工程建设影响较大。以丹巴县革什扎镇柯尔金村呷业沟泥石流为例,通过对其主要发育特征进行调查分析,在现场和室内试验成果基础上,采用数值模拟技术并对其危险性进行评价,并根据泥石流的堆积深度及堆积深度与流速的乘积进行危险高低的界定,对类似泥石流特征分析危险性评价具有借鉴意义。 展开更多
关键词 大坡降短沟道泥石流 发育特征 危害程度 危险性评价
原文传递
基于风险三要素的评估方法在土壤污染隐患排查中的应用
19
作者 吴海俊 郭燕群 +2 位作者 张文镇 罗衡 符祥德 《山东化工》 2025年第6期253-257,260,共6页
土壤污染隐患排查是确保土壤环境质量、预防和减少土壤污染的重要措施。主要排查生产经营活动中涉及有毒有害物质的场所、设施设备。但现有方法存在主观性强,土壤污染隐患风险等级划分不清的问题。基于“污染源-迁移途径-污染迹象”风... 土壤污染隐患排查是确保土壤环境质量、预防和减少土壤污染的重要措施。主要排查生产经营活动中涉及有毒有害物质的场所、设施设备。但现有方法存在主观性强,土壤污染隐患风险等级划分不清的问题。基于“污染源-迁移途径-污染迹象”风险三要素,创新构建了土壤污染隐患风险评估方法。该方法通过量化评分,将土壤污染隐患等级划分为高、中、低三个风险等级,弥补了已有方法存在的缺陷。该方法首次在海南某石油化工企业进行了应用示范,对9个重点区域场所进行了土壤污染隐患等级划分,结果显示:0个高风险区域、3个中风险区域、6个低风险区域。提出的评估方法为土壤污染隐患排查提供了新的技术路径,有助于企业和监管部门更精准地识别和管理高风险区域,为制定针对性的土壤污染防控措施提供了科学依据。 展开更多
关键词 土壤污染 隐患排查 风险等级 评估方法
在线阅读 下载PDF
基于模糊粒子群的多回程物流配送线路规划方法
20
作者 芮飞 《陇东学院学报》 2025年第2期32-36,共5页
目前常规的配送线路规划方法主要以配送开销或单位配送路线长度作为优化目标,并结合配送空间环境方面的限制对约束条件进行设计,由于忽略了配送过程中障碍物对配送效果的阻碍程度,导致算法的规划效果不佳。对此,提出基于模糊粒子群的多... 目前常规的配送线路规划方法主要以配送开销或单位配送路线长度作为优化目标,并结合配送空间环境方面的限制对约束条件进行设计,由于忽略了配送过程中障碍物对配送效果的阻碍程度,导致算法的规划效果不佳。对此,提出基于模糊粒子群的多回程物流配送线路规划方法。首先,结合栅格法,根据障碍物信息对栅格编码,构建栅格编码与坐标之间的转换关系。其次,引入栅格危险度,对障碍物的阻碍程度表征。再次,以配送线路长度和配送危险度作为目标,构建出多目标函数,并结合配送设备的运行性能对约束条件设计。最后,利用粒子群算法,对构建出的物流配送线路规划函数迭代寻优,在约束条件下求解多目标函数,从而输出最优规划方案。在实验中,检验了该方法的规划效果。测试结果表明,采用该方法规划回程物流配送线路时,配送成本较低,具备较为理想的规划效果。 展开更多
关键词 粒子群算法 物流配送 路线规划 栅格危险度
在线阅读 下载PDF
上一页 1 2 19 下一页 到第
使用帮助 返回顶部