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Neonatal ketamine exposure-induced hippocampal neuroapoptosis in the developing brain impairs adult spatial learning ability 预览
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作者 Dan Lyu Ning Tang +2 位作者 Andrew W. Womack Yong-Jin He Qing Lin 《中国神经再生研究:英文版》 SCIE CAS CSCD 2020年第5期880-886,共7页
Ketamine exposure can lead to selective neuroapoptosis in the developing brain.p66ShcA,the cellular adapter protein expressed selectively in immature neurons,is a known pro-apoptotic molecule that triggers neuroapopto... Ketamine exposure can lead to selective neuroapoptosis in the developing brain.p66ShcA,the cellular adapter protein expressed selectively in immature neurons,is a known pro-apoptotic molecule that triggers neuroapoptosis when activated.Sprague-Dawley rats at postnatal day 7 were subcutaneously injected in the neck with ketamine 20 mg/kg,six times at 2-hour intervals.At 0,1,3,and 6 hours after final injection,western blot assay was used to detect the expression of cleaved caspase-3,p66ShcA,and phosphorylated p66ShcA.We found that the expression of activated p66ShcA and caspase-3 increased after ketamine exposure and peaked at 3 hours.The same procedure was performed on a different group of rats.At the age of 4 weeks,spatial learning and memory abilities were tested with the Morris water maze.Latency to find the hidden platform for these rats was longer than it was for control rats,although the residence time in the target quadrant was similar.These findings indicate that ketamine exposure resulted in p66ShcA being activated in the course of an apoptotic cascade during the neonatal period.This may have contributed to the deficit in spatial learning and memory that persisted into adulthood.The experimental protocol was approved by the Institutional Animal Care and Use Committee at the University of Texas at Arlington,USA (approval No.A13.008) on January 22,2013. 展开更多
关键词 caspase-3 DEVELOPMENTAL neuroapoptosis hippocampus KETAMINE MORRIS water MAZE N-METHYL-D-ASPARTATE acid receptors p66ShcA SPATIAL learning
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Spatiotemporal characteristics of the expansion of an urban agglomeration and its effect on the eco-environment: Case study on the northern slope of the Tianshan Mountains
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作者 Chuanglin FANG Qian GAO +1 位作者 Xiaolei ZHANG Weiguo CHENG 《中国科学:地球科学英文版》 SCIE EI CAS CSCD 2019年第9期1461-1472,共12页
Urban agglomerations, which are highly integrated urban groups, form during the advanced stages of industrialization and urban development. The urban agglomeration on the northern slope of the Tianshan Mountains is on... Urban agglomerations, which are highly integrated urban groups, form during the advanced stages of industrialization and urban development. The urban agglomeration on the northern slope of the Tianshan Mountains is one of the 19 urban agglomerations promoted by China’s 13th Five-Year Plan and a key area of urbanization in Xinjiang. Based on remote sensing data, we analyzed the expansion of construction land in the urban agglomeration on the northern slope of the Tianshan Mountains and its effect on ecological value in 1980–2015. The results show that the expansion of construction land significantly affected ecological value in the study area over the past 35 years. Among land use types, grassland was the dominant contributor to changes in ecological value;its contribution rate reached 66.27% with an interannual variation of only 5%. The contribution rate of urban and rural residential land along with industrial and mining lands was very low(0.82%), while the interannual variation was large(86%). The area of construction land in the urban agglomeration expanded from 1,067 to 2,586 km~2, and the conversions of different land use types had different effects on ecological value. Among land use types, the conversions of lowcoverage grassland and dry land made the largest contributions to changes in ecological value. During the study period, a total of 1,685 km~2 of ecological land, 69.91% of which belonged to cultivated land and grassland, was converted into construction land.A total area of 1,082 km~2 of dry land and low-coverage grassland was converted into construction land, accounting for 64.21% of the total ecological land that was converted into construction land. In 2000–2015, the area of urban construction land increased significantly along with the proportion of unused land, including gobi(172 km~2), bare land(65 km~2), and salt-affected land(65 km~2), being converted into construction land. In contrast, the area of construction land that was converted into ecological land was less than 166 km~2. The ar 展开更多
关键词 Urban agglomeration Tianshan Mountains SPATIAL EXPANSION Temporal and SPATIAL evolution Ecological environmental EFFECT
改革开放以来中国交通地理格局演变与规律
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作者 金凤君 陈卓 《地理学报:英文版》 SCIE CSCD 2019年第10期1731-1757,共27页
This paper reviews the process of transportation construction in China and investigates the developmental and spatial characteristics of transportation patterns. The principles of transportation evolution including st... This paper reviews the process of transportation construction in China and investigates the developmental and spatial characteristics of transportation patterns. The principles of transportation evolution including stages, structures and orders are systematically analyzed. The investigation shows that China’s transportation construction mode has upgraded from investment-driven scale expansion to quality improvement driven by efficiency and promotion. The rapid growth and development of transportation networks has significantly influenced economic and social activities in time and space. The resulting spatial convergence and dominance have improved distribution, promoting development of the socioeconomic structure. Regional development that has traditionally been based on corridors has changed into a networked mode centered on cities and metropolitan areas. The transportation pattern follows evolutionary principles. China has been moving from a hierarchical structure to a cascade structure. Simultaneously, the socioeconomic pattern has changed from an axis to a hub-and-spoke structure with a preliminary ordered network. As transportation networks grow, China’s functional spatial structure and ordered network will gradually become stabilized and balanced. 展开更多
关键词 TRANSPORTATION GEOGRAPHY pattern SPATIAL effect SPATIAL order EVOLUTIONARY PRINCIPLE China
基于复杂适应系统理论的旅游地空间演化模式研究(英文)
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作者 杨仲元 殷敏 +1 位作者 徐建刚 林蔚 《地理学报:英文版》 SCIE CSCD 2019年第8期1411-1434,共24页
According to the complex adaptive systems theory, tourist destinations may be regarded as complex adaptive systems formed by multiple adaptive agent interactions and composed of an agent system, tourist attraction sub... According to the complex adaptive systems theory, tourist destinations may be regarded as complex adaptive systems formed by multiple adaptive agent interactions and composed of an agent system, tourist attraction subsystem, tourist service facility subsystem, and external environment system. This paper explores the spatial evolutionary progress of the Southern Anhui tourist area. The period 1979 to 1990 comprised the formation stage of spatial agglomerates, during which tourist attractions centering on Huangshan Scenic Area and Jiuhuashan Scenic Area were gradually exploited and formed scale agglomeration;tourism spatial structure began to show the characteristics of agglomeration development, and Gini indexes of the number of tourists and tourism revenue increased significantly from 0.26 to 0.29, and from 0.33 to 0.35, respectively. From 1991 to 2008, the system experienced a growth stage in which Huangshan Scenic Area and Jiuhuashan Scenic Area were further developed with improved tourist service facilities. Rapid development of Xidi-Hongcun Scenic Area and establishment of Fantawild Tourist Area promoted the formation of more spatial agglomerates with larger scales;Gini indexes of the number of tourists and tourism revenue presented fluctuating changes, reaching low points of 0.15 and 0.25 in 2000 and 0.12 and 0.22 in 2007, respectively. From 2009 to the present day, the system has remained in a blowout-development stage, during which non-linear interactions among agents are strengthened;various emerging development factors generate cultural tourism, vacation tourism, rural tourism and other new tourism products jointly with traditional development factors. New tourism products form a large number of new spatial agglomerates that are interconnected, accelerating the spatial flow of tourists and tourism revenue and reducing the differences in tourism development levels within the region;Gini indexes of the number of tourists and tourism revenue declined steadily from 0.17 and 0.23 in 2009 to 0.12 and 0.15 in 2 展开更多
关键词 complex adaptive system theory SPATIAL structure of TOURIST DESTINATION SPATIAL AGGLOMERATES GINI index Southern Anhui TOURIST area
Spatial correlation of pit and mound topography with canopy gaps in a virgin mixed beech forest,northern Iran 预览
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作者 Hashem Habashi 《林业研究:英文版》 CAS CSCD 2019年第1期295-303,共9页
In a reserved forest parcel in a virgin eastern Hyrcanian mixed beech forest,80 ha was surveyed to determine the pit and mound topography,canopy gaps and dead trees.The aim was to investigate the spatial patterns and ... In a reserved forest parcel in a virgin eastern Hyrcanian mixed beech forest,80 ha was surveyed to determine the pit and mound topography,canopy gaps and dead trees.The aim was to investigate the spatial patterns and correlation of pit and mound features with canopy gaps.Seventy-five canopy gaps and 61 pit and mound features were identified.The univariate first order nearest neighbor(RCE)and bivariate second order test(Ripley’s K)statistic were applied.RCE statistics highlighted a general aggregation pattern for canopy gaps and pits and mounds,while pits and mounds alone were more clumped.Distances between canopy gaps were 130 m average,whereas distances between pit and mound features and dead trees were 60 and 78 m,respectively.Spatial positive correlation of canopy gaps with pits and mounds were observed with all distances.The result of spatial correlations between canopy gaps with pits and mounds confirmed that windthrows cause micro successions in fallen tree ecosystem-scale correlated with gap phase dynamics in the forest community-scale. 展开更多
关键词 PIT and mound Canopy gap MIXED BEECH SPATIAL pattern SPATIAL correlation
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Analysis of Metro Station Ridership Considering Spatial Heterogeneity 预览
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作者 GAN Zuoxian FENG Tao +2 位作者 YANG Min Harry TIMMERMANS LUO Jinyu 《中国地理科学:英文版》 SCIE CSCD 2019年第6期1065-1077,共13页
This study aims to explore the role of spatial heterogeneity in ridership analysis and examine the relationship between built environment, station attributes and urban rapid transit ridership at the station level.Alth... This study aims to explore the role of spatial heterogeneity in ridership analysis and examine the relationship between built environment, station attributes and urban rapid transit ridership at the station level.Although spatial heterogeneity has been widely acknowledged in spatial data analysis, it has been rarely considered in travel behavior studies.Four models(three global models-ordinary least squares(OLS), spatial lag model(SLM), spatial error model(SEM) and one local model-geographically weighted regression(GWR) model) are estimated separately to explore the relationship between various independent variables and station ridership, and identify the influence of spatial heterogeneity.Using the data of built environment and station characteristics, the results of diagnostic identify evidence the existence of spatial heterogeneity in station ridership for the metro network in Nanjing, China.Results of comparing the various goodness-of-fit indicators show that, the GWR model yields the best fit of the data, performance followed by the SEM, SLM and OLS model.The results also demonstrate that population, number of lines, number of feeder buses, number of exits, road density and proportion residential area have a significant impact on station ridership.Moreover, the study pays special attention to the spatial variation in the coefficients of the independent variables and their statistical significance.It underlines the importance of taking spatial heterogeneity into account in the station ridership analysis and the decision-making in urban planning. 展开更多
关键词 spatial heterogeneity rapid transit ridership built environment station level spatial models
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MNR Initiates Spatial Planning Works
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作者 Qian Fang(编译) 《城市规划:英文版》 CSCD 2019年第3期3-4,共2页
In order to implement the Several Opinions of the CPC Central Committee and the State Council on Establishing a Spatial Planning System and Monitoring Related Implementation,the Ministry of Natural Resources(MNR)relea... In order to implement the Several Opinions of the CPC Central Committee and the State Council on Establishing a Spatial Planning System and Monitoring Related Implementation,the Ministry of Natural Resources(MNR)released the Notice on Comprehensively Carrying out the Work of Spatial Planning on May 28,2019,which allocates various works concerning spatial planning,and initiates overall works related to formulation and review and approval of the spatial plan,as well as its implementation management.There are seven items of work clarified in the Notice which are as follows. 展开更多
关键词 RED MNR Initiates SPATIAL PLANNING WORKS SPATIAL
Spatial evolution of green development at provincial level in China 预览
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作者 Yong Wang Haiying Li +2 位作者 Jiangwen Guo Zijun Zhao Hai Yu 《中国人口资源与环境:英文版》 2019年第1期39-48,共10页
Based on the Green Development Indicator System issued by the Chinese government, this study conducted an in-depth evaluation of provincial green development in China, from 2013 to 2016. The findings of the study show... Based on the Green Development Indicator System issued by the Chinese government, this study conducted an in-depth evaluation of provincial green development in China, from 2013 to 2016. The findings of the study showed that:(1) significant regional differences existed across provinces in China regarding green development.(2) In terms of changing trends, the overall level of green development exhibited an upward trend during the years covered by our study, with a faster rising rate of development in eastern and central regions of China than in western ones.(3) In terms of spatial correlation, the spatial autocorrelation of China’s green development was evident. However, the spatial agglomeration of provincial green development gradually waned during the period in 2013–2016.(4) When it comes to drivers of spatial autocorrelation, the comparatively upward trend in the environmental field served as the main factor that drove green development from agglomeration to balance.(5) In terms of convergence, the tendency showed that less developed regions were about to catch up with leading regions in China in green development, especially as regards the dimensions of ecological protection and resource utilization. 展开更多
关键词 Green DEVELOPMENT SPATIAL CORRELATION SPATIAL CONVERGENCE
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Spatial Function Regionalization Based on an Ecological-economic Analysis in Wuxi City, China 预览
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作者 SUN Wei CHEN Wen JIN Zhifeng 《中国地理科学:英文版》 SCIE CSCD 2019年第2期352-362,共11页
As a result of rapid urbanization in China, urban sprawl has increased rapidly, and land-use regulation and smart urban growth are equally important. Spatial function regionalization can provide the scientific groundw... As a result of rapid urbanization in China, urban sprawl has increased rapidly, and land-use regulation and smart urban growth are equally important. Spatial function regionalization can provide the scientific groundwork for the regulation of land use and protection. This paper probes the system of evaluation indices and applies the methods of spatial analysis and classification clustering to the calculation of the ecologically significant value and economically significant value in each evaluation unit. After use of a classification matrix integrated by the two significant values, city space can be divided into four functional types, namely, feasible development area, moderate development area, moderate conservation area and prohibited exploiting area, and these are the basis for spatial development and control. 展开更多
关键词 SPATIAL FUNCTION REGIONALIZATION SPATIAL analysis ecologically SIGNIFICANT VALUE economically SIGNIFICANT VALUE urbanized region
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空间溢出视角下经济集聚对水污染物排放的影响——基于中国339个地级及以上城市数据的实证分析
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作者 周侃 刘汉初 王强 《地理学报:英文版》 SCIE CSCD 2019年第12期2015-2030,共16页
Whether economic agglomeration can promote improvement in environmental quality is of great importance not only to China’s pollution prevention and control plans but also to its future sustainable development.Based o... Whether economic agglomeration can promote improvement in environmental quality is of great importance not only to China’s pollution prevention and control plans but also to its future sustainable development.Based on the COD(Chemical Oxygen Demand)and NH3-N(Ammonia Nitrogen)emissions Database of 339 Cities at the city level in China,this study explores the impact of economic agglomeration on water pollutant emissions,including the differences in magnitude of the impact in relation to city size using an econometric model.The study also examines the spillover effect of economic agglomeration,by conducting univariate and bivariate spatial autocorrelation analysis.The results show that economic agglomeration can effectively reduce water pollutant emissions,and a 1%increase in economic agglomeration could lead to a decrease in COD emissions by 0.117%and NH3-N emissions by 0.102%.Compared with large and megacities,economic agglomeration has a more prominent effect on the emission reduction of water pollution in small-and medium-sized cities.From the perspective of spatial spillover,the interaction between economic agglomeration and water pollutant emissions shows four basic patterns:high agglomeration–high emissions,high agglomeration-low emissions,low agglomeration–high emissions,and low agglomeration–low emissions.The results suggest that the high agglomeration–high emissions regions are mainly distributed in the Beijing-Tianjin-Hebei region,Shandong Peninsula,and the Harbin-Changchun urban agglomeration;thus,local governments should consider the spatial spillover effect of economic agglomeration in formulating appropriate water pollutant mitigation policies. 展开更多
关键词 economic agglomeration water pollutant emissions emission reduction effect city size bivariate spatial autocorrelation spatial spillover effect
Spatial Interactions of China's Steel Output: An Empirical Analysis Based on Chinese Interprovincial Panel Data 预览
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作者 WAN Dai LI Ningting 《景观研究:英文版》 2019年第2期20-27,共8页
In view of the extensive growth of China’s steel production in recent years, this paper analyzed the industrial development background and economic geography theory, and discussed the possible spatial interaction mec... In view of the extensive growth of China’s steel production in recent years, this paper analyzed the industrial development background and economic geography theory, and discussed the possible spatial interaction mechanism. Based on panel data of China’s inter-provincial steel output from 2001 to 2015, using spatial econometric model, this paper also explored whether China’s provincial steel production shows material orientation, market orientation and traffic orientation, and isolated spatial interactions of interprovincial steel output. The results showed that the inter-provincial steel production in China did show both material orientation, market orientation and traffic orientation and that there was a significant negative spatial interaction, indicating that there might be strong competition and a crowing-out effect between neighboring provinces, and that the smaller the spatial scope, the more significant the spatial interactions of steel production. 展开更多
关键词 INTER-PROVINCIAL STEEL OUTPUT Panel data SPATIAL interactions SPATIAL ECONOMETRICS
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QSM-IDM -A novel quadrature spatial modulation based on interleaving division multiplexing for multiple antenna system 预览
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作者 Sherif K. El Dyasti Esam A.A. Hagras Hadia El-Hennawy 《数字通信与网络:英文版》 2019年第3期183-188,共6页
Quadrature Spatial Modulation (QSM) is a high spectral efficiency Multiple-Input Multiple Output (MIMO) technique used to improve the spectral efficiency of wireless communication systems. The main concept of QSM is t... Quadrature Spatial Modulation (QSM) is a high spectral efficiency Multiple-Input Multiple Output (MIMO) technique used to improve the spectral efficiency of wireless communication systems. The main concept of QSM is to extend the spatial constellation of the conventional Spatial Modulation (SM) in both the in-phase and quadrature components of the data symbol. In this paper, because QSM-based on Interleaxdng Division Multiplexing (IDM) has not been introduced in the literature as a multiple antenna system, we introduced a novel scheme, called QSM system based on Interleaving Division Multiplexing (QSM-IDM). The antenna sets are also applied to a spreader, before being used to assign an antenna number for information transmission. Analysis and simulations for a flat fading channel show that the proposed QSM-IDM method significantly outperforms the original QSM system with the same data rate, while maintaining a relatively acceptable complexity. The obtained simulation results show that the conducted analysis yields significant improvements for the accuracy of the proposed scheme, with satisfactory complexity. 展开更多
关键词 Interleaver DIVISION MULTIPLEXING (IDM) MULTIPLE Input MULTIPLE Output (MIMO) Spatial MODULATION (SM) QUADRATURE Spatial MODULATION (QSM)
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Spatial Distribution of Traditional Chinese Villages and Factors Affecting Their Distribution 预览
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作者 WENG Lisheng 《景观研究:英文版》 2019年第1期29-37,45共10页
Traditional Chinese villages are precious historical and cultural heritage and special tourist attractions.This study took 646 traditional villages that announced by the government in 2012 as an example to analyze the... Traditional Chinese villages are precious historical and cultural heritage and special tourist attractions.This study took 646 traditional villages that announced by the government in 2012 as an example to analyze the spatial structure of the traditional villages in China by means of GIS spatial analysis tools and quantitative analysis methods,namely the nearest distance index,geographic concentration index,Gini coefficient and Lorenz curve.The results showed that:①in terms of the spatial distribution density,the average density of traditional villages in 29 provinces(cities,districts)was 0.70/10,000 km2,showing a large provincial gap;②as for the type of spatial distribution,there was a cluster distribution;and③on the balance of spatial distribution,there were many differences between the east and west,and the distribution was extremely uneven.Based on the above,this study explored the reasons for the uneven spatial distribution,including the natural environment,population migration,the level of traffic accessibility,the degree of government attention,and the level of economic development. 展开更多
关键词 TRADITIONAL VILLAGES SPATIAL DISTRIBUTION SPATIAL analysis Influencing factors China
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Spatial analysis and evaluation of a coal deposit by coupling AHP&GIS techniques 预览
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作者 Nikolaos Paraskevis Christos Roumpos +1 位作者 Nikolaos Stathopoulos Aikaterini Adam 《矿业科学技术学报:英文版》 CSCD 2019年第6期943-953,共11页
Nowadays,the evaluation of coal deposits becomes crucial,due to many uncontrollable factors,which affect the energy sector.A comparative evaluation of coal deposits is essential for their hierarchical classification r... Nowadays,the evaluation of coal deposits becomes crucial,due to many uncontrollable factors,which affect the energy sector.A comparative evaluation of coal deposits is essential for their hierarchical classification regarding their sustainable exploitation,when compared to other coal deposits or competitive fuels,which may be used as alternative solutions for electricity generation.In this paper,a method for spatial analysis and evaluation of a lignite deposit is proposed,by creating four spatial key indicators via GIS analysis,which are then aggregated by applying a weighted linear combination.The analytical hierarchy process is applied to estimate the relative weights of the indicators,in order to perform a weighted cartographic overlay.Through the synthesis of the indicators,an overall,total spatial quality indicator is calculated.The weighted analysis was shown to be more effective compared to the unweighted one,because it can provide more reliable results regarding the exploitation of the examined lignite deposit.The implementation of GIS-based analytical hierarchy process in spatial analysis and evaluation of lignite deposits,in terms of sustainable exploitation,demonstrates that this method can be extensively applied for evaluating the economic potential of mineral deposits. 展开更多
关键词 Lignite/coal deposit Spatial analysis Evaluation Cartographic overlay Analytical hierarchy process Geographic information systems Weighted linear combination(WLC) Weighted spatial quality indicator(WSQI)
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Micro-Scanning Error Correction Technique for an Optical Micro-Scanning Thermal Microscope Imaging System 预览
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作者 Meijing Gao Ying Han +3 位作者 Qiushi Geng Yong Zhao Bozhi Zhang Liuzhu Wang 《北京理工大学学报:英文版》 EI CAS 2019年第3期510-518,共9页
An error correction technique for the micro-scanning instrument of the optical micro-scanning thermal microscope imaging system is proposed. The technique is based on micro-scanning technology combined with the propos... An error correction technique for the micro-scanning instrument of the optical micro-scanning thermal microscope imaging system is proposed. The technique is based on micro-scanning technology combined with the proposed second-order oversampling reconstruction algorithm and local gradient image reconstruction algorithm. In this paper, we describe the local gradient image reconstruction model, the error correction technique, down-sampling model and the error correction principle. In this paper, we use a Lena original image and four low-resolution images obtained from the standard half-pixel displacement to simulate and verify the effectiveness of the proposed technique. In order to verify the effectiveness of the proposed technique, two groups of low-resolution thermal microscope images are collected by the actual thermal microscope imaging system for experimental study. Simulations and experiments show that the proposed technique can reduce the optical micro-scanning errors, improve the imaging effect of the system and improve the system's spatial resolution. It can be applied to other electro-optical imaging systems to improve their resolution. 展开更多
关键词 thermal microscope imaging system OPTICAL micro-scanning local gradient image RECONSTRUCTION second-order OVERSAMPLING RECONSTRUCTION spatial resolution
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Diversifying Top-κRoutes with Spatial Constraints
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作者 Hong-Fei Xu Yu Gu +2 位作者 Jian-Zhong Qi Jia-Yuan He Ge Yu 《计算机科学技术学报:英文版》 SCIE EI CSCD 2019年第4期818-838,共21页
Trip recommendation has become increasingly popular with the rapid growth of check-in data in location-based social networks.Most existing studies focused only on the popularity of trips.In this paper,we consider furt... Trip recommendation has become increasingly popular with the rapid growth of check-in data in location-based social networks.Most existing studies focused only on the popularity of trips.In this paper,we consider further the usability of trip recommendation results through spatial diversification.We thereby formulate a new type of queries named spatial diversified top-κroutes(SDκR)query.This type of queries finds k trip routes with the highest popularity,each of which starts at a given starting point,consumes travel time within a given time budget,and passes through points of interest(POIs)of given categories.Any two trip routes returned are diversified to a certain degree defined by the spatial distance between the two routes.We show that the SDkR problem is NP-hard.We propose two precise algorithms to solve the problem.The first algorithm starts with identifying all candidate routes that satisfy the query constraints,and then searches for theκ-route combination with the highest popularity.The second algorithm identifies the candidate routes and builds up the optimalκ-route combination progressively at the same time.Further,we propose an approximate algorithm to obtain even higher query efficiency with precision bounds.We demonstrate the effectiveness and efficiency of the proposed algorithms on real datasets.Our experimental results show that our algorithms find popular routes with diversified POI locations.Our approximate algorithm saves up to 90%of query time compared with the baseline algorithms. 展开更多
关键词 TRIP RECOMMENDATION spatial DIVERSITY ROUTE SEARCH CHECK-IN data
Assessment of causes and future deforestation in the mountainous tropical forest of Timor Island, Indonesia
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作者 PUJIONO Eko SADONO Ronggo +1 位作者 HARTONO IMRON Muhammad Ali 《山地科学学报:英文版》 SCIE CSCD 2019年第10期2215-2231,共17页
The Mutis-Timau Forest Complex,one of the remaining mountainous tropical forest areas in Timor Island,eastern Indonesia that covers an area of 31,984 ha,tends to decrease gradually.Efforts to secure mountain forest fu... The Mutis-Timau Forest Complex,one of the remaining mountainous tropical forest areas in Timor Island,eastern Indonesia that covers an area of 31,984 ha,tends to decrease gradually.Efforts to secure mountain forest functions and counteract the negative impact of declining forest areas are often constrained by data uncertainty on factors contributing to deforestation.For this reason,this study attempts to develop models of deforestation and predict future deforestation in the Mutis-Timau Forest Complex.We constructed models of deforestation that describe the relationship between deforestation and factors contributing to deforestation using spatial statistical models.In this model,we used the deforestation data for the 1987-2017 period obtained from a previous study as dependent variables and the potential causes of deforestation generated from Geographic Information System spatial analysis as independent variables.Using the probability of deforestation derived from the model,we predicted future deforestation under two different scenarios,namely,business-as-usual(as the reference scenario)and reducing emission fromdeforestation and forest degradation.Our findings showed that a positive relationship exists between probability of deforestation,distance to the settlement,and population density variables,whereas a negative relationship exists between likelihood of deforestation,elevation,slope,distance to the road,distance to the savanna,and forest management unit variables.During the 2017-2030 period,under the business-as-usual scenario,the Mutis-Timau Forest Complex will lose 1327.65 ha in forest area with an annual deforestation rate of 0.54%.Meanwhile,under the reducing emission from deforestation and forest degradation scenario,the overall forest loss was estimated to be 1237.11 ha with an annual deforestation rate of 0.50%.The predicted area of avoided deforestation in 2017-2030 under the reducing emission from deforestation and forest degradation scenario was 90.54 ha.Such data and information are important for 展开更多
关键词 Mountainous tropical FOREST DEFORESTATION Spatial statistical model GEOGRAPHIC information system Reducing emission from DEFORESTATION and FOREST degradation
Hierarchical Area Partitioning Method of Urban Road Networks Matching 预览
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作者 Bohua HUANG Wei ZHONG +1 位作者 Renjian ZHAI Qing ZHOU 《测绘学报(英文版)》 2019年第3期55-67,共13页
In view of the “Node-Arc” data model of road network in the aspect of structured expressing the deficiencies, the hierarchical area partitioning of road network based on the principle of stroke, which made road netw... In view of the “Node-Arc” data model of road network in the aspect of structured expressing the deficiencies, the hierarchical area partitioning of road network based on the principle of stroke, which made road network space structure characteristics of the expression with the hierarchical feature was designed. Based on road hierarchy and connected relationship with the area domain boundaries, the road in the area was hierarchically divided. A hierarchical model was established based on “whole-part-object” data model. Finally, the model of urban road network matching is proposed, which used consistency evaluation model selected matching objects from high-grade road to the low-level road. The experiment results indicated that the method was suitable to solve the road matching problem with typical urban features. 展开更多
关键词 ROAD NETWORK STROKE HIERARCHICAL SPATIAL structure characteristics MATCHING
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Does Rapid Urbanization Trigger Significant Increase of Cumulative Heavy Rains in China? 预览
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作者 Feng KONG 《亚洲农业研究:英文版》 2019年第6期25-32,共8页
Severe disasters caused by extreme precipitation events have attracted more and more attention. The relationship between climate change and extreme precipitation has become the hottest scientific frontier issue. The s... Severe disasters caused by extreme precipitation events have attracted more and more attention. The relationship between climate change and extreme precipitation has become the hottest scientific frontier issue. The study of daily torrential rain observations from 659 meteorological stations in China from 1951 to 2010 shows that rapid urbanization may have triggered a significant increase in heavy rains in China. It reached following conclusions: China’s interdecadal heavy rainfall amount,rainy days and rain intensity increased significantly,with an increase of 68. 71%,60. 15% and 11. 52%,respectively. The increase in the number of stations was 84. 22%,84. 22% and 54. 48%,respectively. It showed time change of " rapid-slow-rapid increase" and spatial change of gradual increase from southeastern coast to central China,southwest,north China,and northeastern regions. Rapid urbanization factors,including secondary industry output( GDP2),urban population ratio( UP),annual average haze days( HD),are likely to be the main causes of the increase in heavy rains in China. Their explanations of the variance of heavy rainfall amount( HRA),rainy day( RD) and rain intensity( RI) in China reached 61. 54%,58. 48% and 65. 54%,respectively,of which only the explanation of variance of heavy rainfall amount,rainy days and rain intensity was as high as 25. 93%,22. 98%and 26. 64%,respectively. However,explanation of variance of climatic factors including WPSH( West Pacific Subtropical High),ENSO( El Ni1 o-Southern Oscillation) AMO( Atlantic Interdecadal Oscillation),and AAO( Antarctic Oscillation) was only 24. 30%,26. 23%,and 21. 92%,respectively. Compared with the rapid urbanization forcing factor,the impact of these climatic factors was only one third of the former. The panel data of China’s county-level total population and annual average of visibility days were significantly correlated with China’s interdecadal heavy rainfall amount,rainy days and rain intensity. Their spatial correlation coefficient increased gradually from 展开更多
关键词 CUMULATIVE heavy RAIN Human activities URBANIZATION TRIGGERING factors Spatial and temporal pattern China
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Analysis of irregular repetition spatially-coupled slotted ALOHA
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作者 Hanxiao YU Zesong FEI +3 位作者 Congzhe CAO Ming XIAO Dai JIA Neng YE 《中国科学:信息科学(英文版)》 SCIE EI CSCD 2019年第8期18-30,共13页
Contention-based access is a promising technology for massive and sporadic transmissions. In this paper, we propose a novel contention-based multiple access scheme, named irregular repetition spatiallycoupled slotted ... Contention-based access is a promising technology for massive and sporadic transmissions. In this paper, we propose a novel contention-based multiple access scheme, named irregular repetition spatiallycoupled slotted ALOHA(IRSC-SA), motivated by the spatial coupling and irregular repetition techniques.There are different classes of users and slots in IRSC-SA, which result in unequal protection for different users. Considering that, we derive a novel density evolution(DE) method, which deals with unequal packet protection and introduces Bayesian reasoning to analyze the throughput threshold of the proposed IRSC-SA.Theoretical analysis and simulation results show that the proposed scheme achieves better asymptotic threshold and system packet throughput performance than the conventional spatially-coupled slotted ALOHA. 展开更多
关键词 SPATIAL coupling CODED slotted ALOHA contention-based access density evolution IRREGULAR REPETITION
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