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高强度片区类地面连接效能量化指标研究
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作者 彭飞 付本臣 曾诗彦 《建筑技艺(中英文)》 2024年第6期72-80,共9页
高强度片区立体开发及连接缺乏管控指标,对过往建筑设计与城市设计领域关于类地面、立体城市、多层地表等内容进行梳理总结,进而提出“高强度片区类地面”的概念,并提出能够表征类地面连接效能的三个指标,即面积系数、楼层连通率和类地... 高强度片区立体开发及连接缺乏管控指标,对过往建筑设计与城市设计领域关于类地面、立体城市、多层地表等内容进行梳理总结,进而提出“高强度片区类地面”的概念,并提出能够表征类地面连接效能的三个指标,即面积系数、楼层连通率和类地连接工效比,为总设计师在城市设计阶段的立体连接导控提供更全面、精准、高效的量化评估方法。 展开更多
关键词 城市设计 高强度片区 类地面 连接效能
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建立类地面建筑环境——改善高层建筑可居性的一种途径 被引量:3
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作者 龚兆先 《中外建筑》 1996年第6期39-41,共3页
高层建筑自一百多年前诞生发展至今。已遍布世界各国城市,从芝加哥到纽约直至广大发展中国家的都市,其发展趋势锐不可挡。高层建筑的发展不仅数量上直线上升,高度上也节节拔高。美国纽约的西尔斯大厦曾因其442米的高度傲视全球数十年,... 高层建筑自一百多年前诞生发展至今。已遍布世界各国城市,从芝加哥到纽约直至广大发展中国家的都市,其发展趋势锐不可挡。高层建筑的发展不仅数量上直线上升,高度上也节节拔高。美国纽约的西尔斯大厦曾因其442米的高度傲视全球数十年,而今却只能退居其次;纽约、芝加哥不断展示近千米高层建筑的设计蓝图,日本东京也不失时机推出在下世纪建设高一千米"空中都市"的雄伟计划……高层建筑几乎成了现代都市人的图腾! 但是,高层建筑除了创造了现代都市的图腾之外,还给我们带来了什么呢? 展开更多
关键词 建筑设计 高层建筑 类地面 建筑环境 可居性
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保护饮用水水源地必须严格管控《第一类污染物》 被引量:1
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作者 傅国伟 《海峡科技与产业》 2016年第11期125-128,共4页
饮用水水源地是国务院规定实行最严格水资源管理制度的保护区,但一再出现不同于常规污染物的"第一类污染物"——重金属的污染问题。目前许多管理者只顾区内水质是否满足地面水环境质量Ⅱ类水质标准,而不顾区内或上游地企业车... 饮用水水源地是国务院规定实行最严格水资源管理制度的保护区,但一再出现不同于常规污染物的"第一类污染物"——重金属的污染问题。目前许多管理者只顾区内水质是否满足地面水环境质量Ⅱ类水质标准,而不顾区内或上游地企业车间排放的第一类污染物总量是否达到GB8978-96管控标准;也不顾饮用水水源地现实的"环境背景值"。这些涉及法规标准上存在的偏差和错误,致使第一类污染物非法直排或偷排者常有,城乡污水处理厂(处理生活污水)处理后的排水和底泥中也常有。强化管理者严格执法监控第一类污染物的责任是十分必要的。 展开更多
关键词 饮用水水源地 第一污染物 常规污染物 地面水环境质量Ⅱ水质标准 环境背景值 严格监控
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Effects of Vegetation Type on Surface Elevation Change in Liaohe River Delta Wetlands Facing Accelerated Sea Level Rise 被引量:5
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作者 WANG Guodong WANG Ming +3 位作者 JIANG Ming LYU Xianguo HE Xingyuan WU Haitao 《Chinese Geographical Science》 SCIE CSCD 2017年第5期810-817,共8页
Rising sea levels threaten the sustainability of coastal wetlands around the globe. The ability of coastal marshes to maintain their position in the intertidal zone depends on the accumulation of both organic and inor... Rising sea levels threaten the sustainability of coastal wetlands around the globe. The ability of coastal marshes to maintain their position in the intertidal zone depends on the accumulation of both organic and inorganic materials, and vegetation is important in these processes. To study the effects of vegetation type on surface elevation change, we measured surface accretion and elevation change from 2011 to 2016 using rod surface elevation table and feldspar marker horizon method (RSET-MH) in two Phragmites and two Suaeda marshes in the Liaohe River Delta. The Phragmites marshes exhibited higher rates of surface accretion and elevation change than the Suaeda marshes. The two Phragmites marsh sites had average surface elevation change rates at 8.78 mm/yr and 9.26 mm/yr and surface accretion rates at 17.56 mm/yr and 17.88 mm/yr, respectively. At the same time, the two Suaeda marsh sites had average surface elevation change rates at 5.77 mmJyr and 5.91 mm/yr and surface accretion rates at 13.42 mm/yr and 14.38 mm/yr, respectively. The elevation change rates in both the Phragmites marshes and the Suaeda marshes in the Liaohe River Delta could keep pace and even continue to gain elevation relative to averaged sea level rise in the Bohai Sea reported by the 2016 State Oceanic Administration, Peo- ple's Republic of China projection (2.4-5.5 mm/yr) in current situations. Our data suggest that vegetation is important in the accretionary processes and vegetation type could regulate the wetland surface elevation. However, the vulnerability of coastal wetlands in the Liaohe River Delta need further assessment considering the accelerated sea level rise, the high rate of subsidence, and the declining sediment delivery, especially for the Suaeda marshes. 展开更多
关键词 sea level rise wetland elevation surface accretion Phragmites marsh Suaeda marsh Liaohe River Delta
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Steering Vibrational Population Transfer via Double-∑-Type Laser Scheme
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作者 李立航 韩永昌 丛书林 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2015年第1期43-48,I0001,共7页
The vibrational state-selected population transfer from a highly vibrationally excited level to the ground level is of great importance in the preparation of ultra-cold molecules. By using the time-dependent quantum-w... The vibrational state-selected population transfer from a highly vibrationally excited level to the ground level is of great importance in the preparation of ultra-cold molecules. By using the time-dependent quantum-wave-packet method, the population transfer dynamics is investigated theoretically for the HF molecule. A double-E-type laser scheme is proposed to transfer the population from the |v=16〉 level to the ground vibrational level |v=0〉 on the ground electronic state. The scheme consists of two steps: The first step is to transfer the population from |v=16〉 to |v=7〉 via an intermediate level |v=11〉, and the second one is to transfer the population from |v=7〉 to |v=0〉 via |v=3〉. In each step, three vibrational levels form a E-type population transfer path under the action of two temporally overlapped laser pulses. The maximal population-transfer efficiency is obtained by optimizing the laser inten- sities, frequencies, and relative delays. Cases for the pulses in intuitive and counterintuitive sequences are both calculated and compared. It is found that for both cases the population can be efficiently (over 90%) transferred from the |v=-16〉 level to the |v=0〉 level. 展开更多
关键词 Population transfer Wave packet dynamics Vibrational state
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Quantitative Assessment of Impacts of Regional Climate and Human Activities on Saline-alkali Land Changes:A Case Study of Qian'an County,Jilin Province 被引量:3
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作者 LIAN Yi WANG Jie +5 位作者 TU Gang REN Hongling SHEN Baizhu ZHI Keguang LI Shangfeng GAO Zongting 《Chinese Geographical Science》 SCIE CSCD 2010年第1期91-97,共7页
Interdecadal and interannuat variations of saline-alkali land area in Qian'an County, Jilin Province, China were comprehensively analyzed in this paper by means of satellite remote sensing interpretation, field flux ... Interdecadal and interannuat variations of saline-alkali land area in Qian'an County, Jilin Province, China were comprehensively analyzed in this paper by means of satellite remote sensing interpretation, field flux observations and regional climate diagnosis. The results show that on the interannual scale, the impact of climate factors accounts for 71.6% of the total variation of the saline-alkali land area, and that of human activities accounts for 28.4%. Therefore the impact of climate factors is obviously greater than that of human activities. On the interdecadal scale, the impact of climate factors on the increase of the saline-alkali land area accounts for 43.2%, and that of human activities accounts for 56.8%. The impact of human activities on the variation of saline-alkali land area is very clear on the interdecadal scale, and the negative impact of human activities on the environment should not be negligible. Besides, changes in the area of heavy saline-alkali land have some indication for development of saline-alkali land in Qian'an County. 展开更多
关键词 saline-alkali land regional climate change human activities
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室内纺织品装饰配套设计中的设计风格 被引量:1
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作者 张际仲 《大舞台》 2011年第1期69-70,共2页
纺织品的三大支柱是衣用纺织品、家用纺织品和产业用纺织品,在家用纺织品中很大部分是用于室内装饰的,这部分的纺织品就称作室内装饰织物,简称装饰织物。本文就室内纺织品装饰配套设计进行了探讨。
关键词 挂帷遮饰 家具覆饰 地面铺饰 墙面贴饰
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Climate Change and Environmental Impact Caused by Anthropogenic 被引量:1
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作者 Omar Khodjet Kesba Mustapha Kamel Mihoubi Abdelhamid Hebbouche 《Journal of Environmental Science and Engineering(B)》 2012年第5期668-672,共5页
For the last two decades the world has undergone a population explosion which has been accompanied by a speeding up of urbanization and land use for industrial and agricultural products. These involve a vast increase ... For the last two decades the world has undergone a population explosion which has been accompanied by a speeding up of urbanization and land use for industrial and agricultural products. These involve a vast increase in the discharge of pollutants into very different receiving water bodies, and have had adverse effects on the various components of the environment. For a long time, human has concerned a little of the natural environment. It is obvious that this variation in surface temperature of the earth increases the level of sea due to snowmelt. So climate change is manifested by many phenomena: floods, droughts, fires, tornadoes, cyclones, earthquakes, volcanic eruptions, diseases etc.. The statement today is dramatic. Entire regions were devastated and many rivers and lakes have become polluted around the world. Pollution has it nature which is hard to be absorbed. Where did the different pollutants come from? What are the risks to the aquatic environment? To prevent and combat the general decline of these ecosystems, it is important to distinguish and determine the effects of different sources of pollution and any changes that may suffer the physical environment. The climate depends primarily on changes in earth orbit parameters, which affect the solar radiation received by the earth surface. Therefore, human participates strongly to these changes, for example, pollution is the main reason to argue the greenhouse effect, an increase of anthropogenic carbon dioxide (CO2) into the atmosphere, which promotes global warming to the planet. These modifications are already applied in order to ensure durable development in water resources by controlling discharges into streams to preserve water resources for future generations and to ensure reconciliation between man-climate and environment. 展开更多
关键词 Human CLIMATE environment anthropogenic pollution SOIL water.
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Some Analyses on Effects of Site Classification on Ground Motion Characteristics in the Chi-Chi,Taiwan Earthquake
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作者 Dong Di Yang Jian Liu Rui 《Earthquake Research in China》 2006年第4期435-448,共14页
According to the epicenter distance and the site classification, the 404 groups of earthquake recordings of the main shock of the Chi-Chi, Taiwan China earthquake in 1999 are catalogued. Based on these data, we analyz... According to the epicenter distance and the site classification, the 404 groups of earthquake recordings of the main shock of the Chi-Chi, Taiwan China earthquake in 1999 are catalogued. Based on these data, we analyze the statistical features of duration, PGA, envelopes and the response spectra ratio of the horizontal and vertical components of the acceleration recordings. The results of these analyses show that the effect of site classification on the acceleration of various components is obvious; furthermore, fault direction also has certain effects on the characteristics of the horizontal components of ground motion. The detailed research results are as follows: ( 1 ) the duration of the horizontal components of acceleration records increases with the softening of the site; (2) the direction of fault slip has some effects on PGA's attenuation features; (3) the average envelopes of acceleration records at different distances and site dames are basically single peak functions of time and the envelopes of horizontal and vertical components of ground motion are obviously different; (4) with the same epicenter distance, EW/NS response spectrum ratios tend to approximate 1.0 as the site becomes softer and the period shorter. V/H response spectrum ratios in short periods (〈 0. 1s) increase with the softening of site, however, V/H ratios within the long-period range ( 〉 characteristic period) decrease with the softening of the site, and the decrease of V/EW ratio speeds up relatively. 展开更多
关键词 SITE DURATION ENVELOPE Response spectrum ratio
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Monitoring of Ionizing Radiation and Rain Intensity during May to October 2015 in S^o Jos~ dos Campos, Brazil
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作者 Inacio Malmonge Martin Thiago Adriano dos Santos +2 位作者 Franklin Andrade da Silva Marcelo Pego Gomes Bogos Nubar Sismanoglu 《Journal of Environmental Science and Engineering(B)》 2016年第3期115-117,共3页
Radiation affects the environment and local human activity in any location of the earth's surface. Due to this fact, the aim of this study was to monitor the ionizing radiation and rain intensity using portable devic... Radiation affects the environment and local human activity in any location of the earth's surface. Due to this fact, the aim of this study was to monitor the ionizing radiation and rain intensity using portable devices. During May 23 to October 2, 2015, it was made measures the intensity of gamma radiation from 30 keV to 10.0 MeV at a height of 25 meters in Sao Jos6 dos Campos city, SP, Brazil. It was used a crystal of sodium iodide scintillator 3 - 3 inches coupled to a photomultiplier and associated electronic. The measurements were made continually with minute's interval throughout the period and it was monitored rain intensity every minute at the same height of the tower. In this job, it was possible to correlate rain-radiation and it was observed which gamma radiation has a directly proportional relationship with rain and visible frequency of 1 day. 展开更多
关键词 Gamma radiation rain intensity radon gas gamma scintillator.
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神奇的“纳米武器”
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作者 周健 《国防技术基础》 2001年第2期41-42,共2页
<正> 纳米是一种度量单位,1纳米为百万分之一毫米,即十亿分之一米。纳米结构通常是指尺寸在100纳米以下的微小结构,在这种水平上对物质和材料进行研究处理的技术称为纳米技术。纳米技术以空前的分辨率为人类提示了一个可见的原子... <正> 纳米是一种度量单位,1纳米为百万分之一毫米,即十亿分之一米。纳米结构通常是指尺寸在100纳米以下的微小结构,在这种水平上对物质和材料进行研究处理的技术称为纳米技术。纳米技术以空前的分辨率为人类提示了一个可见的原子、分子世界,它的最终目标是直接以原子和分子来构造具有特定功能的产品。人们普遍认为。 展开更多
关键词 纳米技术 纳米武器 飞行器 水中兵器 "地面爬行"武器
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Land Use and Land Cover Change on Slope in Qiandongnan Prefecture of Southwest China 被引量:4
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作者 LU Liang GUO Luo ZHAO Song-ting 《Journal of Mountain Science》 SCIE CSCD 2014年第3期762-773,共12页
This study uses DEM (Digital Elevation Model) data and remote sensing maps of the study area in 1993, 1999, and 2009 to analyze the slope gradient change of land use patterns in Qiandongnan Prefecture, Guizhou provi... This study uses DEM (Digital Elevation Model) data and remote sensing maps of the study area in 1993, 1999, and 2009 to analyze the slope gradient change of land use patterns in Qiandongnan Prefecture, Guizhou province, China. The land use data were classified into five types, forest, farmland, grassland, water and built-up, the slope gradients were divided into four grades. Indices for analyzing land use features were defined by their proportions, transformation matrixes, land use degree and changes The results showed that all land use types can be found at every gradient. Generally, with the slope degree increased, the area of forest being augmented as well, while the area of the other land use types (farmland, grassland and build-up) declined. Moreover, a mass of farmland were shifted from other land use types from o° to 25°, while a quantity of forest were transformed from the other land use types on 〉 25° from 2993 to 2009. In terms of land use degree and changes, the area of farmland and buildup land use types decreased when slope degree increased. Finally, we calculated the five landscape pattern metrics: Patch Density (PD) value, Largest Patch Index (LPI), Shannon's Diversity Index (SHDI), Area-Weighted Mean Shape Index (AWMSI) and Contagion Index (CONTAG). The results of metricsanalysis showed that PD values, SHDI values and CONTA values had a similar variation trend, that is, they decreased when slope degree increased. There was no obvious variation trend on LPI value. 展开更多
关键词 Land use Land cover change Spatialgradient slope Landscape metrics Qiandongnanprefecture
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Narrative Environmental Ethics, Nature Writing, and Ecological Science as Tradition: Towards a Sponsoring Ground of Concern
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作者 John Charles Ryan 《Journal of Philosophy Study》 2012年第11期822-834,共13页
Over the last 30 years, environmental philosophers and ecological researchers have turned their attention to the possibilities of narratives: the stories people tell about their lives in conjunction with the human an... Over the last 30 years, environmental philosophers and ecological researchers have turned their attention to the possibilities of narratives: the stories people tell about their lives in conjunction with the human and non-human agents they live with. An interest in narrative environmental ethics reflects a re-evaluation of canonical ecophilosophical texts. Works such as Paul W. Taylor's Respect for Nature suggest an essentialist view of environmental ethics in which predetermined principles are imposed on places and situations. On the other hand, Aldo Leopold's A Sand County Almanac combines first-person prose with science-based explanations of the "biotic pyramid" towards the development of a land ethic. Examples, such as Leopold's, of narrative ethics are thought to offer relational, place-based, non-authoritative, and non-anthropocentric models. This article examines three critical components of environmental narratives: self, context, and tradition. In order for environmental narratives to advance ecological ethics, they must be accompanied by the tradition of natural science (geology, ecology, and evolution) to provide the "sponsoring ground" for ethical concern and action. The role of natural science as a tradition--and indeed one of many--in narrative ethics provides the basis for ecological selfhood in the context of place. These assertions will be supported by an analysis of the environmental narratives of Karen Warren and Jim Cheney. However, in the temporally expansive and ecologically conscious poetic narratives of John Kinsella we find an environmental ethics deeply rooted in the material realities of place. 展开更多
关键词 narratives ecopoetics environmental ethics ecological science
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Bird Monitoring to Conserve Salitre Wetland in Bogotá: Strengthening Local Efforts in Conservation
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作者 Abril-Pulido Elizabeth Pachón Carlos Barragán-Barrera Dalia 《Journal of Environmental Science and Engineering(B)》 2012年第10期1162-1166,共5页
Abstract: The Bogota Savannah was great Lake Humboldt 20,000 years ago. In the early 20th century, there were 50,000 ha of wetlands in Bogotá, but now this area has reduced to around 800 ha, due principally to h... Abstract: The Bogota Savannah was great Lake Humboldt 20,000 years ago. In the early 20th century, there were 50,000 ha of wetlands in Bogotá, but now this area has reduced to around 800 ha, due principally to human activities like industry, city-planning expansion, and agriculture. Actually, there are 13 wetlands and two lakes in Bogotá. SW (Salitre wetland) is an aquatic area that contains migratory and resident bird's species. Around this wetland, there are some urbanization and recreational areas that affect this natural habitat. Due to city-planning expansion, the city government wanted to build a great area to perform massive public events on the Salitre area. From June 2009 to June 2010, the researchers have made bird monitoring and recorded the SW as a very important habitat for birds; they demonstrated that this site offered them food and protection. Migratory species like Dendroica striata, Porzana carolina, Porphyrio martinica, Actitis macularia, Piranga rubra, Contopus cooperi and Contopus virens, inhabit this area. Most of the birds in SW use the area primarily for feeding and roosting, and the authors have recorded presence of eggs and chicks. In this way, the authors have demonstrated that this area is very important for migratory and resident birds. Currently, SW is in process to be officially designated as a wetland after many efforts. However, conservation and educational efforts should be taken into consideration for the protection and conservation of this wetland. 展开更多
关键词 SW (Salitre wetland) bird species conservation.
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Numerical analysis on the heat transfer of three types of nozzles for the hypersonic long-run wind tunnel 被引量:1
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作者 XING YunFei ZHONG FengQuan +1 位作者 LI DongXia ZHANG XinYu 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2015年第3期470-475,共6页
The hypersonic long-run scramjet test tunnel is one of the key ground facilities for the studies of ramjet/scramjet and hypersonic thermal management.Due to the significantly large heat loading,the nozzle of the tunne... The hypersonic long-run scramjet test tunnel is one of the key ground facilities for the studies of ramjet/scramjet and hypersonic thermal management.Due to the significantly large heat loading,the nozzle of the tunnel facility demands effective cooling protection.In this work,the two-dimensional,three-dimensional and axisymmetric Mach 6.5 nozzles at an inlet total temperature of 1840 K and a total pressure of 6.4 MPa were studied with main focuses on the properties of aerodynamic heating of nozzles.The present work aims to provide insights into the design of an effective cooling system for the nozzle and other components of the hypersonic long-run wind tunnel. 展开更多
关键词 hypersonic scramjet test tunnel NOZZLE aerodynamic heating convective heat transfer
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Normal scalar curvature and a pinching theorem in S^m×R and H^m×R 被引量:7
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作者 CHEN Qun 1,2 & CUI Qing 3,1,1 School of Mathematics and Statistics,Wuhan University,Wuhan 430079,China 2 International Center for Theoretical Physics,Trieste 34100,Italy 3 School of Mathematics,Southwest Jiaotong University,Chengdu 610031,China 《Science China Mathematics》 SCIE 2011年第9期1977-1984,共8页
We obtain an inequality in Sm×R and Hm×R which is similar to DDVV conjecture.As an application,we show that a minimal submanifold in H m×R with nonnegative scalar curvature must be a surface of the type... We obtain an inequality in Sm×R and Hm×R which is similar to DDVV conjecture.As an application,we show that a minimal submanifold in H m×R with nonnegative scalar curvature must be a surface of the type γ×R,where γ is a geodesic in H m.In addition,we get a pinching theorem in Sm×R. 展开更多
关键词 product spaces DDVV conjecture pinching theorem
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Modeling diurnal variation of ground thermal radiance images using energy balance model and endmember composing technique 被引量:2
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作者 ZHAO LiMin GU XingFa +4 位作者 YU Tao WAN Wei XIONG Pan XIE YanHua ZHANG Lun 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第11期3223-3231,共9页
Modeling and analyzing dynamic changes of land thermal radiance scenes play an important role in thermal remote sensing. In this paper, the diurnal variation of ground surface thermal scene is mainly discussed. Firstl... Modeling and analyzing dynamic changes of land thermal radiance scenes play an important role in thermal remote sensing. In this paper, the diurnal variation of ground surface thermal scene is mainly discussed. Firstly, based on the land surface energy balance equation, the diurnal variation of land surface temperatures (LSTs) over bare land covers were simulated by an analyt- ical thermal model with second harmonic terms, and the diurnal LST variation of vegetation canopy was simulated using the Cupid model. Secondly, normalized difference vegetation index (NDVI), normalized difference water index (NDWI), and ratio resident-area index (RRI) were used to evaluate the endmember abundance of four land cover types including vegetation, bare soil, impervious and water area, which were calculated from IKONOS visible and near infrared (VNIR) bands. Finally, the thermal radiance scenes at various times and view angles were modeled based on the linear-energy-mixing hypothesis. The re- suits showed that the simulated daily LST variations for vegetated and bare surfaces are correlated with the measured values with a maximum standard deviation of 2.7℃, that land thermal radiant textures with high-resolution are restored from the lin- ear-energy-mixing method, and that the information abundance of the scene are related to the distribution of land cover, the imaging time, and the view angle. 展开更多
关键词 surface energy balance model surface temperature endmember index thermal radiance scene modeling high-spatialresolution
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Hierarchical method of task assignment for multiple cooperating UAV teams 被引量:17
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作者 Xiaoxuan Hu Huawei Ma +1 位作者 Qingsong Ye He Luo 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2015年第5期1000-1009,共10页
The problem of task assignment for multiple cooperating unmanned aerial vehicle(UAV) teams is considered. Multiple UAVs forming several small teams are needed to perform attack tasks on a set of predetermined ground t... The problem of task assignment for multiple cooperating unmanned aerial vehicle(UAV) teams is considered. Multiple UAVs forming several small teams are needed to perform attack tasks on a set of predetermined ground targets. A hierarchical task assignment method is presented to address the problem. It breaks the original problem down to three levels of sub-problems: target clustering, cluster allocation and target assignment. The first two sub-problems are centrally solved by using clustering algorithms and integer linear programming, respectively, and the third sub-problem is solved in a distributed and parallel manner, using a mixed integer linear programming model and an improved ant colony algorithm. The proposed hierarchical method can reduce the computational complexity of the task assignment problem considerably, especially when the number of tasks or the number of UAVs is large. Experimental results show that this method is feasible and more efficient than non-hierarchical methods. 展开更多
关键词 unmanned aerial vehicle (UAV) task assignment CLUSTERING integer linear programming ant colony optimization(ACO) algorithm
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Mapping Soil Texture of a Plain Area Using Fuzzy-c-Means Clustering Method Based on Land Surface Diurnal Temperature Difference 被引量:7
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作者 WANG De-Cai ZHANG Gan-Lin +3 位作者 PAN Xian-Zhang ZHAO Yu-Guo ZHAO Ming-Song WANG Gai-Fen 《Pedosphere》 SCIE CAS CSCD 2012年第3期394-403,共10页
The use of landscape covariates to variability of soil properties in similar estimate soil properties is not suitable topographic and vegetation conditions. for the areas of low relief due to the high A new method wa... The use of landscape covariates to variability of soil properties in similar estimate soil properties is not suitable topographic and vegetation conditions. for the areas of low relief due to the high A new method was implemented to map regional soil texture (in terms of sand, silt and clay contents) by hypothesizing that the change in the land surface diurnal temperature difference (DTD) is related to soil texture in case of a relatively homogeneous rainfall input. To examine this hypothesis, the DTDs from moderate resolution imagine spectroradiometer (MODIS) during a selected time period, i.e., after a heavy rainfall between autumn harvest and autumn sowing, were classified using fuzzy-c-means (FCM) clustering. Six classes were generated, and for each class, the sand (〉 0.05 mm), silt (0.002-0.05 mm) and clay (〈 0.002 mm) contents at the location of maximum membership value were considered as the typical values of that class. A weighted average model was then used to digitally map soil texture. The results showed that the predicted map quite accurately reflected the regional soil variation. A validation dataset produced estimates of error for the predicted maps of sand, silt and clay contents at root mean of squared error values of 8.4%, 7.8% and 2.3%, respectively, which is satisfactory in a practical context. This study thus provided a methodology that can help improve the accuracy and efficiency of soil texture mapping in plain areas using easily available data sources. 展开更多
关键词 digital soil mapping land surface temperature low relief area MODIS remote sensing
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