期刊文献+
共找到1,579篇文章
< 1 2 79 >
每页显示 20 50 100
Reconstruction of Ore-controlling Structures Resulting from Magmatic Intrusion into the Tongling Ore Cluster Area during the Yanshanian Epoch 被引量:13
1
作者 DENG Jun WANG Qingfei +5 位作者 YANG Liqiang GAO Bangfei HUANG Dinghua LIU Yah XU Hao JIANG Shaoqing 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2007年第2期287-296,共10页
The Tongling ore cluster area experienced intensive compression and associated shearing during the Indosinian-Yanshanian Epoch, which formed a trunk ore-controlling fold and fault system in the caprock. The magmatic i... The Tongling ore cluster area experienced intensive compression and associated shearing during the Indosinian-Yanshanian Epoch, which formed a trunk ore-controlling fold and fault system in the caprock. The magmatic intrusion in the Yanshanian Epoch induced a multi-stage unmixing of poly-phase fluids, resulting in mineralization characterized by multi-layer, wide-range, and multiform styles. The magmatic intrusion in the Tongling area not only supplied the essential ore-forming materials, but also reconstructed the ore-controlling structures according to a trend surface simulation of the following five strata boundaries: Silurian-Devonian, Devonian-Carboniferous, Carboniferous- Permian, Middle Permian-Upper Permian and Permian -Triassic. The result of this simulation shows that there exists a significant difference between the strata in the upper part and those in the lower. The lower trend surfaces are antiform whereas the upper trend surfaces are synform. In addition, superposing of the trend surfaces of adjacent bed boundaries (such as, Silurian-Devonian boundary superposed upon Devonian-Carboniferous boundary) shows that the lower trend surface always pierces the one above. Moreover, the position and orientation of the pierced parts of the different superposed trend surfaces are similar and show E-W-trending zonal distribution in accordance with the distribution of the regional E-W-trending magmatic-metallogenic belt. Based on comprehensive analysis of the mechanical properties of the strata, structural deformation mechanisms, and field phenomena, it seems that the special characteristics of the stratal trend surface resulted from jacking due to magmatic intrusion into the caprock previously controlled by an E-W-trending basement fault. Therefore, it is deduced that the major ore-controlling structures, which formed during regional horizontal compression, were reconstructed by the vertical jacking function of ore-forming magmas during the Yanshanian Epoch. During the ore-forming process, the local vertical jacking of magmas, coupled with the regional horizontal compression, optimized an extensive environment in the fluid- conduit network and accelerated the unmixing of poly-phase fluids following magmatic emplacement. Jacking also strengthened the vertical and lateral fluid-guiding structures, supplying more suitable physical conditions for multi-layer emplacement and wide-ranging transport of poly-phase fluids. 展开更多
关键词 magma trend surface multi-layer mineralization UNMIXING Tongling ore cluster area YANSHANIAN
在线阅读 下载PDF
Division of hydroclimatic area over China seas—Ⅱ.Cluster analysis and fuzzy ISODATA. 被引量:2
2
作者 Chen Shangji and Yao Shiyu 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1994年第2期213-224,共12页
In this paper, the tree cluster analysis and ISODATA of fuzzy cluster are made on the basis of the results(Chen et al, 1993) obtained by using the principal component analysis based on the hydroclimatic values over th... In this paper, the tree cluster analysis and ISODATA of fuzzy cluster are made on the basis of the results(Chen et al, 1993) obtained by using the principal component analysis based on the hydroclimatic values over the years of the China seas,where the climatic field may be divided into three climatic zones, 9 hydroclimatic regions and 1 climatic subregion Comparison of the distribution characteristics of hydrologic seasons with those of marine fauna and flora indicates that each climatic region possesses its inherent seasonal characteristics and biota distribution, and corresponds with each other. This fact proves that the division of the above-mentioned 10 climatic regions is reliable. 展开更多
关键词 China seas division of hydroclimatic area cluster ISODATA fuzzy cluster
在线阅读 下载PDF
Fault Detection Based on Hierarchical Cluster Analysis in Wide Area Backup Protection System 被引量:2
3
作者 Yagang ZHANG Jinfang ZHANG +1 位作者 Jing MA Zengping WANG 《Energy and Power Engineering》 2009年第1期21-27,共7页
In wide area backup protection of electric power systems, the prerequisite of protection device's accurate, fast and reliable performance is its corresponding fault type and fault location can be discriminated qui... In wide area backup protection of electric power systems, the prerequisite of protection device's accurate, fast and reliable performance is its corresponding fault type and fault location can be discriminated quickly and defined exactly. In our study, global information will be introduced into the backup protection system. By analyzing and computing real-time PMU measurements, basing on cluster analysis theory, we are using mainly hierarchical cluster analysis to search after the statistical laws of electrical quantities' marked changes. Then we carry out fast and exact detection of fault components and fault sections, and finally accomplish fault isolation. The facts show that the fault detection of fault component (fault section) can be performed successfully by hierarchical cluster analysis and calculation. The results of hierarchical cluster analysis are accurate and reliable, and the dendrograms of hierarchical cluster analysis are in intuition. 展开更多
关键词 WIDE area BACKUP protection PHASOR MEASUREMENT unit PMU WIDE area MEASUREMENT system WAMS fault detection cluster analysis
暂未订购
基于local-area的Internet路由级拓扑抽象算法 被引量:4
4
作者 李乔 张兆心 《高技术通讯》 CAS CSCD 北大核心 2011年第9期922-927,共6页
通过分析Internet的本地聚集特性,给出了local-area和connect—area的定义,并基于此,为提高并行网络模拟性能,提出一种新型拓扑抽象算法——基于local—area的拓扑抽象(TABLA)算法。TABLA算法在给定的聚合粒度下,迭代搜索网络内... 通过分析Internet的本地聚集特性,给出了local-area和connect—area的定义,并基于此,为提高并行网络模拟性能,提出一种新型拓扑抽象算法——基于local—area的拓扑抽象(TABLA)算法。TABLA算法在给定的聚合粒度下,迭代搜索网络内的local-area,对拓扑进行抽象。模拟结果表明在Internet路由级拓扑上采用该算法,拓扑规模大约压缩为原先的45%,初始化内存节省约60%,模拟运行时间约缩短80%,大幅度提高了并行网络模拟性能。 展开更多
关键词 并行网络模拟 拓扑抽象 聚合粒度 本地域(local-area)
在线阅读 下载PDF
阿尔山地区8种食用菌营养品质的综合评价
5
作者 李向鹏 王晓琴 +2 位作者 孟勐 吴皓 曹阳 《中国瓜菜》 北大核心 2026年第1期126-133,共8页
本研究以阿尔山地区的8种食用菌为材料,对其粗蛋白、总糖和粗脂肪等9种有机营养成分及粗灰分和6种无机矿质元素的含量进行测定,采用主成分分析和聚类分析对8种食用菌的营养品质进行综合评价。结果表明,在8种食用菌中,15种营养物质含量... 本研究以阿尔山地区的8种食用菌为材料,对其粗蛋白、总糖和粗脂肪等9种有机营养成分及粗灰分和6种无机矿质元素的含量进行测定,采用主成分分析和聚类分析对8种食用菌的营养品质进行综合评价。结果表明,在8种食用菌中,15种营养物质含量的变异系数范围为9.45%~114.37%,其中氯和淀粉含量的变异系数分别为114.37%和100.64%,说明这8种食用菌的营养物质含量差异较大。主成分分析中,前两个主成分的累计贡献率为90.955%,可代表8种食用菌的大部分营养品质数据。8种食用菌的综合得分范围为-2.407~1.741,其中花脸蘑的综合得分最高,营养品质最佳,小黄蘑、小白蘑菇和赤松茸的综合得分在0.083~1.244之间,营养品质较好,滑子蘑的综合得分最低,营养品质较差。聚类分析结果表明,8种食用菌可聚成4类,第Ⅰ类包含2种、第Ⅱ类包含4种、第Ⅲ类包含1种、第Ⅳ类包含1种,其中小黄蘑和花脸蘑二者聚为一类,主要表现为粗蛋白、粗脂肪、总脂肪酸和镁含量较高,可作为优质食用菌。综上,主成分分析与聚类分析的结果相似,花脸蘑的综合品质最好。研究结果可为阿尔山地区食用菌产业的发展提供科学的参考价值。 展开更多
关键词 食用菌 营养品质 主成分分析 聚类分析 阿尔山地区
在线阅读 下载PDF
使用Pluswell Cluster实现双机热备 被引量:1
6
作者 彭英 季飞 《科技广场》 2009年第3期58-59,共2页
本文论述了双机热备实验在SAN网络基础课程中的重要性,阐述了利用Pluswell Cluster模拟双机热备实验的优势,并给出了实际的实验环境和步骤。
关键词 存储区域网 双机热备实验
在线阅读 下载PDF
The study of size-grade of prehistoric settlements in the Circum-Songshan area based on SOFM network 被引量:5
7
作者 LU Peng TIAN Yan YANG Ruixia 《Journal of Geographical Sciences》 SCIE CSCD 2013年第3期538-548,共11页
Choosing site area, cultural layer thickness, significant relics and significant re- mains as the variables, we applied cluster analysis to the ancient settlements of four cultural periods, respectively, which were Pe... Choosing site area, cultural layer thickness, significant relics and significant re- mains as the variables, we applied cluster analysis to the ancient settlements of four cultural periods, respectively, which were Peiligang, Yangshao, Longshan and Xiashang, in 9000-3000 a BP, around Songshan Mountain. Through application of the SOFM (self-organizing feature map) networks, every type of ancient settlements was classified into different size-grades. By this means, the Peiligang settlements were divided into two grades, Yangshao and Longshan settlements were divided into three grades, respectively, and Xi- ashang settlements were divided into four grades. The results suggested that the size-grade diversity of ancient settlements was not significant during the Peiligang period in this area. Around the middle-late Yangshao period (5000 a BP), the size-grade diversity of ancient settlements began to appear, a process that continued during the Longshan period and finally matured in the Xiashang period. Moreover, the results reflected the regional differences in cultural characteristics in a particular period, which were mainly represented in that there were three Peitigang cultural systems distributed in different areas. Such differences also existed in the spatial distributive characteristics between the Xia and Shang cultures. Based on the size-grade study of ancient settlements in the Circum-Songshan area, it was found that the SOFM networks method was very suitable for size-grade classification of ancient settle- ments, since, using this method, adjacent cells would compete and learn from each other, a benefit that reduced the effect on classification by the inaccuracy of site acreages. 展开更多
关键词 SOFM Circum-Songshan area prehistoric settlement cluster analysis size-grade
原文传递
Dry/wet climate zoning and delimitation of arid areas of Northwest China based on a data-driven fashion 被引量:9
8
作者 QingLing GENG PuTe WU +2 位作者 QingFeng ZHANG XiNing ZHAO YuBao WANG 《Journal of Arid Land》 SCIE CSCD 2014年第3期287-299,共13页
The division of arid areas is important in water and land resources management, planning and for a long-term agricultural, economic and social planning. Northwest China (NW) dominates the main arid areas in China. T... The division of arid areas is important in water and land resources management, planning and for a long-term agricultural, economic and social planning. Northwest China (NW) dominates the main arid areas in China. There is thus a need to adopt adequate concepts relative to the scope of arid areas of NW China and identify its climate types and characteristics. In this study, we analyzed climatic data over the last 30 years (1981-2010) from 191 stations in three provinces and three autonomous regions of NW China. The factor-cluster analysis technique (FC), an objective and automated method was employed to classify the dry/wet climate zones. The traditional methods with predefined thresholds were adopted for providing a comparison with FC. The results showed that the wet/dry climate zones by FC were mainly distributed along mountains, rivers and desert borders. Climate-division boundaries relied heavily on the major terrain features surrounding the grouped stations. It also showed that the climate was dry in the plain sandy areas but relatively wet in the high mountain areas. FC method can reflect the climate characteristics more fully in NW China with varied and complicated topography, and outperform the tradi- tional climate classifications. Arid areas of NW China were defined as four climate types, including five resultant classes in FC classifications. The Qinling and Da Hinggan Mountains were two important boundaries, besides main administrative boundaries. The results also indicated that there are some differences between two traditional clas- sifications. The precipitation moved and fluctuated to an extent, which confirmed that climate change played an important role in the dry/wet climate zoning, and the boundaries of dry/wet climate zones might change and migrate with time. This paper is expected to provide a more in-depth understanding on the climate characteristics in arid areas of NW China, and then contribute to formulate reasonable water and land management planning and agri- cultural production programs. 展开更多
关键词 arid areas CLASSIFICATIONS climate zoning factor-cluster analysis
在线阅读 下载PDF
Regionalization of River Basins Using Cluster Ensemble 被引量:1
9
作者 Sangeeta Ahuja 《Journal of Water Resource and Protection》 2012年第7期560-566,共7页
In the wake of global water scarcity, forecasting of water quantity and quality, regionalization of river basins has attracted serious attention of the hydrology researchers. It has become an important area of researc... In the wake of global water scarcity, forecasting of water quantity and quality, regionalization of river basins has attracted serious attention of the hydrology researchers. It has become an important area of research to enhance the quality of prediction of yield in river basins. In this paper, we analyzed the data of Godavari basin, and regionalize it using a cluster ensemble method. Cluster Ensemble methods are commonly used to enhance the quality of clustering by combining multiple clustering schemes to produce a more robust scheme delivering similar homogeneous basins. The goal is to identify, analyse and describe hydrologically similar catchments using cluster analysis. Clustering has been done using RCDA cluster ensemble algorithm, which is based on discriminant analysis. The algorithm takes H base clustering schemes each with K clusters, obtained by any clustering method, as input and constructs discriminant function for each one of them. Subsequently, all the data tuples are predicted using H discriminant functions for cluster membership. Tuples with consistent predictions are assigned to the clusters, while tuples with inconsistent predictions are analyzed further and either assigned to clusters or declared as noise. Clustering results of RCDA algorithm have been compared with Best of k-means and Clue cluster ensemble of R software using traditional clustering quality measures. Further, domain knowledge based comparison has also been performed. All the results are encouraging and indicate better regionalization of the Godavari basin data. 展开更多
关键词 K-MEANS cluster ENSEMBLE HYDROLOGY RUNOFF CULTIVATION area Precipitation Field Capacity
暂未订购
Clustering Analysis of the Climate in Tobacco Planting Zone of Yunnan
10
作者 JIN Ya-bo QU Ran +1 位作者 LI Tian-fu WEI Jian-yu 《Meteorological and Environmental Research》 CAS 2012年第12期77-84,共8页
[Objective] The research aimed to study clustering of the six climatic factors in Yunnan tobacco planting zone. [Method] 6 meteorological elements in 89 tobacco-growing counties and 12 sub-prefectures were conducted c... [Objective] The research aimed to study clustering of the six climatic factors in Yunnan tobacco planting zone. [Method] 6 meteorological elements in 89 tobacco-growing counties and 12 sub-prefectures were conducted clustering analysis. According to indicator and climate characteristics of the each type, climate in tobacco planting area of Yunnan Province was divided. [Result] Climate in tobacco planting area of Yunnan Province could be divided into eight types: Jiangchuan (24 counties, belonged to northern and central subtropical climate belts), Songming (27 counties, belonged to northern subtropical and central, south, north temperate climate belts), Tengchong (3 counties, belonged to northern subtropical climate belt), Mile (12 counties, belonged to central and southern subtropical climate belts), Qiubei (11 counties, belonged to southern subtropical climate belt), Yanjin (4 counties, belonged to central subtropical humid climate belt), Yuanjiang (4 counties, belonged to southern subtropical and northern tropical climate belts), Zhenxiong (3 counties, belonged to warm temperate and northern subtropical climate belts) were eight representatives. Among 1-8 eco-zones, domestic and foreign cities where climate reached level-one similarity were respectively 3, 1, 1, 0, 1, 1, 0 and 1, up to level-two similarity, respectively 12, 15, 3, 13, 13, 1, 5 and 3. Among 8 major ecological zones, similar distance of the city reaching level-one similarity was in the range of 0.28 to 0.45, and similar degree was the highest. Variety introduction among these places would be successful. Similar distance of the city reaching level-two similarity was between 0.51 and 1.00, and similar degree was higher. Mutual variety introduction had high successful rate in these places. [Conclusion] The research provided theoretical basis for selecting new suitable tobacco variety and optimizing tobacco variety layout in different zones. 展开更多
关键词 Tobacco growing area System clustering Climatic zoning YUNNAN China
在线阅读 下载PDF
农文旅融合目标下乡村旅游集聚区规划研究 被引量:1
11
作者 刘芳 吴松涛 周小新 《低温建筑技术》 2025年第2期139-144,共6页
文中旨在解决哈尔滨城郊村庄在人、地、产、景方面的乡村振兴困境,通过总体定位、分区实施、集约发展、优化布局、以农为基、以文铸魂、创新引领等方法,构建哈尔滨城郊乡村旅游集聚区发展的新模式,并以哈尔滨市平盛街道为例,展开了乡村... 文中旨在解决哈尔滨城郊村庄在人、地、产、景方面的乡村振兴困境,通过总体定位、分区实施、集约发展、优化布局、以农为基、以文铸魂、创新引领等方法,构建哈尔滨城郊乡村旅游集聚区发展的新模式,并以哈尔滨市平盛街道为例,展开了乡村旅游集聚区产业延伸与融合以及空间形态扩展与演化的规划研究。实践证明此模式对于优化乡村旅游集聚区的土地利用、产业发展、文化传承、景观营造等具有较强的理论指导意义。 展开更多
关键词 农文旅融合 乡村旅游集聚区 哈尔滨城郊乡村 空间形态扩展
在线阅读 下载PDF
A Neighborhood Analysis of Underage Tobacco Sales within the Serving Area of a Canadian Public Health Unit
12
作者 Saber Fallahpour Tanya Navaneelan +1 位作者 Kristy McBeth Prithwish De 《Open Journal of Statistics》 2017年第6期920-935,共16页
Despite the fact that the sale of tobacco to minors is illegal in Ontario, youth are still able to purchase tobacco. This study aims to determine the geographic variations of underage tobacco sales at the neighborhood... Despite the fact that the sale of tobacco to minors is illegal in Ontario, youth are still able to purchase tobacco. This study aims to determine the geographic variations of underage tobacco sales at the neighborhood level within the Windsor-Essex County Health Unit. Data were collected on all inspections of tobacco retail stores from 2007 to 2011 in the Windsor-Essex County Health Unit. Data were split into season 1 (September-February) and season 2 (March-August) to assess a possible seasonal effect. Relative risks were calculated for each dissemination area (DA) by modeling the risks in a hierarchical Bayesian fashion, incorporating appropriate random effects terms for both spatially correlated and uncorrelated random errors with adjustments for neighborhood income. The association between violation rate and proximity to a school was assessed through a buffer analysis. Elliptical analysis detected a significant cluster of high risk DAs in season 1 in Windsor (p-value = 0.022) but no significant cluster in season 2. Some DAs exhibited higher relative risks of tobacco sales to minors, however after adjusting the model for neighborhood income no excess risk was observed. The results of the buffer analysis showed that in season 1 there was a significantly higher probability (p-value = 0.045) of tobacco vendors located closer to schools to sell tobacco to minors. This analysis demonstrates the utility of a systematic approach to identifying neighborhoods with higher risks of tobacco sales to minors. The insights provided by this exploratory, ecologic study are valuable for program planning and directing tobacco enforcement efforts to high risk areas. 展开更多
关键词 TOBACCO DISSEMINATION area Bayesian Disease Mapping cluster Buffer ANALYSIS
暂未订购
基于波簇区间的挥发性有机气体红外光谱光谱波长选择算法
13
作者 严玥 许世豪 +1 位作者 何海星月 周雪 《电子测量与仪器学报》 北大核心 2025年第3期34-43,共10页
以特征波长点簇类和吸收峰区间筛选串联选择模式,提出了一种基于波簇区间的波长选择算法用于挥发性有机气体红外光谱波长选择。首先进行簇类聚集,在保留足够特征吸收峰特性同时避免算法波长区间机械划分或随机不确定性,接着设计改进移... 以特征波长点簇类和吸收峰区间筛选串联选择模式,提出了一种基于波簇区间的波长选择算法用于挥发性有机气体红外光谱波长选择。首先进行簇类聚集,在保留足够特征吸收峰特性同时避免算法波长区间机械划分或随机不确定性,接着设计改进移动窗口方式对同一簇类中的波长点进行再次筛选,保留最能代表光谱特征的波长区间用于后期各种模型预测。用苯乙烯、对二甲苯和邻二甲苯近红外光谱数据在偏最小二乘法、偏最小二乘、岭回归、支持向量机4种模型上进行了验证分析,结果表明在不影响模型精度前提下,数据集可缩小至原来的43.71%~36.35%;以3种气体各2种浓度全排列组合混合气体为数据集,通过3种不同结构卷积神经网络(CNN)模型上光谱波形选择前后实验对比,在保证预测精度的同时验证了算法在降低机器学习模型复杂度上的有效性,波长选择前后在3种CNN预测模型上运行效率提升90%。 展开更多
关键词 红外光谱 波长选择算法 波簇区 神经网络 预测精度
原文传递
花岗岩地区群发性降雨滑坡孕灾条件敏感性研究——以桂东南北流市为例 被引量:1
14
作者 赵建军 赖琪毅 +6 位作者 马彦飞 何娜 刘朔维 陈海伊 常鸣 吴福 刘振宇 《中国地质灾害与防治学报》 2025年第2期63-71,共9页
近年来,极端强降雨在我国南方全强风化花岗岩地区诱发了多起群发性滑坡事件,造成了严重的损失。由于区域性的极端气候、厚层风化花岗岩与不规范切坡等因素,群发滑坡频频发生。但滑坡发育特征及孕灾条件尚不明确,给地质灾害监测和防治带... 近年来,极端强降雨在我国南方全强风化花岗岩地区诱发了多起群发性滑坡事件,造成了严重的损失。由于区域性的极端气候、厚层风化花岗岩与不规范切坡等因素,群发滑坡频频发生。但滑坡发育特征及孕灾条件尚不明确,给地质灾害监测和防治带来挑战。文章以广西北流市花岗岩地区为研究区,采用现场调查、遥感解译与XG-boost模型,探讨了降雨型群发滑坡的发育特征、时空分布规律、破坏模式和孕灾条件敏感性。结果表明,区内两起暴雨事件共引发滑坡1 670处,以中小规模为主,占总数量的72.57%。群发滑坡集中发育于高程<300 m、坡度>75°的切坡地形下,表现出分布范围广、规模小、数量多、即雨即滑、爆发性强的特点,主要形成剪切滑移型、滑塌型及流滑型(碎屑流)三类破坏模式。距居民点距离(概率贡献为22.22%)、坡度(15.25%)、高程(14.47%)及植被覆盖度(12.01%)是诱发花岗岩地区降雨型群发滑坡的主要孕灾条件。本研究可为花岗岩地区降雨型群发滑坡的研究提供依据,在防控减灾方面具有重要意义。 展开更多
关键词 花岗岩地区 极端降雨 群发性滑坡 破坏模式 孕灾条件
在线阅读 下载PDF
基于K-Means和IE模型的采空区地表安全性评价指标研究
15
作者 赵博 俞奎 《金属矿山》 北大核心 2025年第6期221-229,共9页
随着智能算法在灾害评价领域的深入应用,构建合理的评价指标体系对于实现复杂采空区地表安全性的高效评价至关重要。然而,传统指标选取方法存在主观性强、干扰因素多、效率低及数字化程度不足等诸多瓶颈。为此,构建了一种基于K-Means聚... 随着智能算法在灾害评价领域的深入应用,构建合理的评价指标体系对于实现复杂采空区地表安全性的高效评价至关重要。然而,传统指标选取方法存在主观性强、干扰因素多、效率低及数字化程度不足等诸多瓶颈。为此,构建了一种基于K-Means聚类算法和IE理论的高效精确评价指标模型。该模型首先从采空区地表灾害作用机理出发,广泛筛选潜在评价指标;进而利用K-Means算法对这些指标进行聚类筛选,以降低指标信息表达的冗余性和复杂度;通过IE理论计算提炼出对安全性影响显著的关键指标,构建出一套采空区复杂场地安全性评价的指标体系。为验证指标体系的合理性,结合PCA和熵权法进行检验评估;将模型应用于某采空区地区,并与常用方法的评价结果进行对比。结果表明:该模型成功将38个初选指标精简至8个关键指标,所构建的评价指标体系仅用21.1%的指标特征便能表征87.9%的原始指标信息,显著降低了计算工作量,提升了评价效率。该研究成果不仅为采空区地表稳定性评价提供了一种新颖方法,而且为相关领域的研究提供了理论支撑,具有较高的理论价值和实践意义。 展开更多
关键词 采空区 评价指标 聚类算法 信息熵
在线阅读 下载PDF
考虑峰丛洼地内涝滞洪的分布式岩溶水文模型
16
作者 陈立华 杨文哲 +1 位作者 陈航 黄文举 《水科学进展》 北大核心 2025年第4期646-656,共11页
峰丛洼地内涝滞洪是岩溶流域水循环的关键环节。针对岩溶流域水文模型刻画峰丛洼地滞洪过程的不足,提出基于水量平衡原理的洼地内涝滞洪模拟方法,构建考虑滞洪影响的分布式新安江岩溶(DK-XAJ-DF)水文模型,以刁江流域为研究区,开展流域... 峰丛洼地内涝滞洪是岩溶流域水循环的关键环节。针对岩溶流域水文模型刻画峰丛洼地滞洪过程的不足,提出基于水量平衡原理的洼地内涝滞洪模拟方法,构建考虑滞洪影响的分布式新安江岩溶(DK-XAJ-DF)水文模型,以刁江流域为研究区,开展流域内部龙头峰丛洼地内涝滞洪及河口、马陇水文站的逐小时径流模拟。结果表明:龙头洼地逐小时滞洪量模拟确定性系数达0.90,相对洪量误差为0.77%;验证期河口站与马陇站逐小时径流模拟确定性系数分别为0.85和0.89,相对径流总量误差分别为3.0%和-4.4%;相较原模型,改进后的模型将马陇站的洪峰流量与峰现时间的合格率分别从65%与70%提升至70%与80%。DK-XAJ-DF模型通过量化滞洪效应提升了岩溶区洪水模拟精度。 展开更多
关键词 洪水预报 内涝滞洪 分布式岩溶水文模型 岩溶区 峰丛洼地
在线阅读 下载PDF
Semi-Supervised Clustering Fingerprint Positioning Algorithm Based on Distance Constraints
17
作者 Ying Xia Zhongzhao Zhang +1 位作者 Lin Ma Yao Wang 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2015年第6期55-61,共7页
With the rapid development of WLAN( Wireless Local Area Network) technology,an important target of indoor positioning systems is to improve the positioning accuracy while reducing the online computation.In this paper,... With the rapid development of WLAN( Wireless Local Area Network) technology,an important target of indoor positioning systems is to improve the positioning accuracy while reducing the online computation.In this paper,it proposes a novel fingerprint positioning algorithm known as semi-supervised affinity propagation clustering based on distance function constraints. We show that by employing affinity propagation techniques,it is able to use a fractional labeled data to adjust similarity matrix of signal space to cluster reference points with high accuracy. The semi-supervised APC uses a combination of machine learning,clustering analysis and fingerprinting algorithm. By collecting data and testing our algorithm in a realistic indoor WLAN environment,the experimental results indicate that the proposed algorithm can improve positioning accuracy while reduce the online localization computation,as compared with the widely used K nearest neighbor and maximum likelihood estimation algorithms. 展开更多
关键词 wireless local area network(WLAN) SEMI-SUPERVISED similarity matrix clusterING affinity propagation
在线阅读 下载PDF
智能制造专业群与武汉都市圈区域产业协同发展的创新实践——以长江工程职业技术学院为例
18
作者 陈琳 熊巍 肖青 《长江工程职业技术学院学报》 2025年第3期47-50,62,共5页
以长江工程职业技术学院智能制造专业群为例,探讨了武汉都市圈产业发展格局下的高职院校智能制造专业群的改革与实践。通过分析武汉都市圈的产业发展现状,结合智能制造专业群实际情况提出了专业群建设路径:对接产业需求、构建高水平专业... 以长江工程职业技术学院智能制造专业群为例,探讨了武汉都市圈产业发展格局下的高职院校智能制造专业群的改革与实践。通过分析武汉都市圈的产业发展现状,结合智能制造专业群实际情况提出了专业群建设路径:对接产业需求、构建高水平专业群,创新培养模式、加强重点专业建设,立足岗位能力、构建模块化课程体系,师资与实训平台建设等措施,提升智能制造专业群的教学质量,更好地服务于武汉都市圈的制造产业。 展开更多
关键词 武汉都市圈 智能制造 专业群 产教融合
在线阅读 下载PDF
黔西南烤烟质量特征及其关键气象驱动因子分析
19
作者 严锦申 黄瑞寅 +6 位作者 杨天乐 张震 黄嘉杰 左安建 蓝军 梁旭源 蔡一霞 《作物研究》 2025年第5期455-465,共11页
为探明黔西南的烤烟质量特征及其关键气象驱动因子,以黔西南州6个主要植烟县为对象,采集36个样点的烟叶及其对应的气象数据,采用模糊数学、层次聚类分析和偏最小二乘回归(PLSR)模型,对不同区域的烟叶质量进行综合评价,并探讨关键气象因... 为探明黔西南的烤烟质量特征及其关键气象驱动因子,以黔西南州6个主要植烟县为对象,采集36个样点的烟叶及其对应的气象数据,采用模糊数学、层次聚类分析和偏最小二乘回归(PLSR)模型,对不同区域的烟叶质量进行综合评价,并探讨关键气象因子对烟叶感官品质的调控作用。结果表明:各样点烟叶质量存在显著差异,根据综合得分可将烟区划分为三类,其中Ⅰ类优质区主要分布于西北部和西南部。烤烟生长前期(还苗期、旺长期)过量降水会抑制烤后烟叶的浓度与劲头,而成熟期适度降水虽有助于提高烟叶的浓度与劲头,但会抑制香型表达。日照时间对烤后烟叶感官风格影响显著,前期日照充足有助于浓度形成,旺长期至成熟期强光则可能抑制香气表达。本研究明确了黔西南烟叶品质的空间格局,明确了感官品质的关键气象驱动因素,可为优化烤烟生态区划、发展优质产区提供理论依据。 展开更多
关键词 烤烟 质量特征 层次聚类 气象因子 黔西南烟区
在线阅读 下载PDF
基于节点聚类的低压台区分布式光伏接入位置研究
20
作者 邵磊 王智男 +2 位作者 刘宏利 李季 赵龙 《天津理工大学学报》 2025年第6期39-45,共7页
分布式接入已成为低压台区光伏发展的必然趋势,传统的接入位置选择方法需要提前预知台区拓扑结构,然而网架庞大的低压配电网不能满足此需求。在此背景下,提出一种基于节点聚类的低压台区分布式光伏接入位置选择方法。利用多峰高斯拟合... 分布式接入已成为低压台区光伏发展的必然趋势,传统的接入位置选择方法需要提前预知台区拓扑结构,然而网架庞大的低压配电网不能满足此需求。在此背景下,提出一种基于节点聚类的低压台区分布式光伏接入位置选择方法。利用多峰高斯拟合提取节点特征,并选用凝聚层次聚类对节点进行类别划分。依据聚类结果建立接入位置选择算法,定义适用于低压台区的节点电压灵敏度概念,对不同类别中心节点进行电压灵敏度计算,进而选择合适的接入位置。以电力系统分析计算软件(electric transient analysis program,ETAP)完成多方案仿真验证,结果表明,该方法能够在未得知台区拓扑情况下分析出最佳的分布式光伏接入位置,具有良好的工程应用前景。 展开更多
关键词 低压台区 分布式光伏 接入位置 节点聚类 电压灵敏度
在线阅读 下载PDF
上一页 1 2 79 下一页 到第
使用帮助 返回顶部