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组件式GIS的土地估价信息系统 被引量:1
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作者 钟晓遇 张永标 《科技咨询导报》 2007年第9期10-10,共1页
从土地定级估价原则、方法及系统总体设计等方面阐述了城镇土地定级估价信息系统设计的一般过程。
关键词 土地定级估价 组件式GIS 信息素统
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Vulnerability of mountain glaciers in China to climate change 被引量:5
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作者 YANG Jian-Ping DING Yong-Jian +1 位作者 LIU Shi-Yin TAN Chun-Ping 《Advances in Climate Change Research》 SCIE CSCD 2015年第3期171-180,共10页
Mountain glaciers in China are an important water source for both China and adjoining countries, and therefore their adaptation to glacier change is crucial in relation to maintaining populations. This study aims to i... Mountain glaciers in China are an important water source for both China and adjoining countries, and therefore their adaptation to glacier change is crucial in relation to maintaining populations. This study aims to improve our understanding of glacial vulnerability to climate change to establish adaptation strategies. A glacial numerical model is developed using spatial principle component analysis (SPCA) supported by remote sensing (RS) and geographical information system (GIS) technologies. The model contains nine factors--slope, aspect, hillshade, elevation a.s.l., air temperature, precipitation, glacial area change percentage, glacial type and glacial area, describing topography, climate, and glacier characteristics. The vulnerability of glaciers to climate change is evaluated during the period of 1961-2007 on a regional scale, and in the 2030s and 2050s based on projections of air temperature and precipitation changes under the IPCC RCP6.0 scenario and of glacier change in the 21st century. Glacial vulnerability is graded into five levels: potential, light, medial, heavy, and very heavy, using natural breaks classification (NBC). The spatial distribution of glacial vulnerability and its temporal changes in the 21st century for the RCP6.0 scenario are analyzed, and the factors influencing vulnerability are discussed. Results show that mountain glaciers in China are very vulnerable to climate change, and 41.2% of glacial areas fall into the levels of heavy and very heavy vulnerability in the period 1961-2007. This is mainly explained by topographical exposure and the high sensitivity of glaciers to climate change. Trends of glacial vulnerability are projected to decline in the 2030s and 2050s, but a declining trend is still high in some regions. In addition to topographical factors, variation in precipitation in the 2030s and 2050s is found to be crucial. 展开更多
关键词 Mountain glaciers Climate change VULNERABILITY PROJECTION
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An adaptive ant colony system algorithm for continuous-space optimization problems 被引量:20
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作者 李艳君 吴铁军 《Journal of Zhejiang University Science》 CSCD 2003年第1期40-46,共7页
Ant colony algorithms comprise a novel category of evolutionary computation methods for optimization problems, especially for sequencing-type combinatorial optimization problems. An adaptive ant colony algorithm is pr... Ant colony algorithms comprise a novel category of evolutionary computation methods for optimization problems, especially for sequencing-type combinatorial optimization problems. An adaptive ant colony algorithm is proposed in this paper to tackle continuous-space optimization problems, using a new objective-function-based heuristic pheromone assignment approach for pheromone update to filtrate solution candidates.Global optimal solutions can be reached more rapidly by self-adjusting the path searching behaviors of the ants according to objective values. The performance of the proposed algorithm is compared with a basic ant colony algorithm and a Square Quadratic Programming approach in solving two benchmark problems with multiple extremes. The results indicated that the efficiency and reliability of the proposed algorithm were greatly improved. 展开更多
关键词 Ant colony algorithm Continuous space optimization Pheromone update strategy
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Population Distribution and Influencing Factors Based on ESDA 被引量:3
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作者 Lv Chen Fan Jie Sun Wei 《Chinese Journal of Population,Resources and Environment》 2012年第3期47-53,共7页
Based on the exploratory spatial data analysis (ESDA) technique and geographic information system (GIS) platform, with statistic data of counties in 2005, this paper confirms that there is a large population densi... Based on the exploratory spatial data analysis (ESDA) technique and geographic information system (GIS) platform, with statistic data of counties in 2005, this paper confirms that there is a large population density gap between counties in 2005 because the Gini coefficient is 0.55. Population distribution does not change a lot during the past decades, and the southeast China is still much more densely populated than the northwest China. The global spa- tial autoeorrelation of population distribution is obvious because Moran's I scores 0.42 and local spatial autocorrelation is partly significant. Climate and elevation are still the main natural influ- encing factors. Meanwhile industrial structure and transportation significantly influence population distribution. Different combinations of natural factors have different effects on population distribution. For a long term, climate and terrain factor stability affect population distribution. But its influence will be weakened by progress of technology. Economic development is the main factor that changes population distribution for a short term. 展开更多
关键词 population distribution geographic information system (GIS) spatial autocorrelation influencing factors
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Spatial patterns of interprovincial mountain geographical names in China and implications for regional governance 被引量:1
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作者 ZHANG Sheng-rui WANG Ying-jie +4 位作者 JU Hong-run ZHANG Tong-yan LI Dai-chao FANG Lei WANG Ying-ying 《Journal of Mountain Science》 SCIE CSCD 2018年第11期2517-2530,共14页
Suffering from fragile environment, poor accessibility and infrastructure, as well as social,political and economic marginality, the interprovincial mountain geographical entities are difficult areas for the regional ... Suffering from fragile environment, poor accessibility and infrastructure, as well as social,political and economic marginality, the interprovincial mountain geographical entities are difficult areas for the regional governance in China.By analyzing the spatial patterns and the influencing factors of the interprovincial mountain geographical names(IMGNs), the goal of this research is to clarify the geographical features of IMGNs and offer alternatives for the management of interprovincial mountain regions in China. The spatial visualization,the analysis of spatial agglomeration and the influencing factors of IMGNs were all implemented under a geographical information system. Results showed that there were 6869 IMGNs in China according to the database of "China's Second National Survey of Geographical Names(2014-2018)",including 4209 mountain geographical names, 1684 mountain peak geographical names and 976 the other mountain geographical names. Hunan Province had the largest number of names while Shanghai had the smallest number of names. In addition, the spatial variance of the mountain peak names and the mountain names were larger than that of the other mountain geographical names, and the IMGNs showed a significant clustering phenomenon in the southern part of China. The relative elevation and the population had an impact on the distribution of the IMGNs. The largest number of the names occurred where the relative elevation was between 1000-2000 m and where the population was between 40-50 million. Density of unnamed interprovincial mountain geographical entities declined from west to east in China. The analysis of generic names of different types of IMGNs implied that the naming of IMGNs is inconsistent. Based on these analyses, it is suggested that the government should take the IMGNs as management units, strengthen the naming of unnamed interprovincial mountain geographical entities, standardize the generic names of IMGNs and identify areas of poverty based on the survey of IMGNs. 展开更多
关键词 Interprovincial mountain geographical names Spatial association Spatial variance GIS Regional governance China
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Crohn's disease genotypes of patients in remission vs relapses after infliximab discontinuation 被引量:1
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作者 Cathy Lu Alistair Waugh +12 位作者 Robert J Bailey Raeleen Cherry Levinus A Dieleman Leah Gramlich Kata Matic Mario Millan Karen I Kroeker Daniel Sadowski Christopher W Teshima Dennis Todoruk Clarence Wong Karen Wong Richard N Fedorak 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第36期5058-5064,共7页
AIM: To investigate genetic differences between Crohn's disease (CD) patients with a sustained remission vs relapsers after discontinuing infliximab while in cortico- steroid-free remission. METHODS: Forty-eight ... AIM: To investigate genetic differences between Crohn's disease (CD) patients with a sustained remission vs relapsers after discontinuing infliximab while in cortico- steroid-free remission. METHODS: Forty-eight CD patients received infliximab and were in full corticosteroid-free clinical remission but then discontinued infliximab for reasons other than a loss of response, were identified by review of an electronic database and charts. Infliximab-associated remis- sion was defined as corticosteroid-free plus normaliza- tion of clinical disease activity [CD activity index (CDAI) 〈 150] during follow-up visits based on physician global assessments. A CD relapse (loss of infliximab-induced remission) was clinically defined as a physician visit for symptoms of disease activity (CDAI 〉 220) and a thera- peutic intervention with CD medication(s), or a hospital- ization with complications related to active CD. Genetic analyses were performed on samples from 14 patients (n = 6 who had a sustained long term remission after stopping infliximab, n -- 8 who rapidly relapsed after stopping infliximab). Nucleotide-binding oligomerization domain 2 (NOD2)/caspase activation recruitment do- main 15 (CARD15) polymorphisms (R702W, G908R and L1007fs) and the inflammatory bowel disease 5 (IBDS) polymorphisms (IGR2060a1 and IGR3081a1) were ana- lyzed in each group. RESULTS: Five single nucleotide polymorphisms of IBD5 and NOD2/CARD15 genes were successfully analyzed for all 14 subjects. There was no signifcant increase in frequency of the NOD2/CARD15 polymor- phisms (R702W, G908R and L1007fs) and the IBD5 polymorphisms (IGR2060al and IGR3081a1) in either group of patients; those whose disease relapsed rap- idly or those who remained in sustained long term remission following the discontinuation of infliximab. Nearly a third of patients in full clinical remission who stopped infliximab for reasons other than loss of re- sponse remained in sustained clinical remission, while two-thirds relapsed rapidly. There was a marked dif- ference in the duration of clinical remission following discontinuance of infliximab between the two groups. The patients who lost remission did so after 1.0 years 4- 0.6 years, while those still in remission were at the time of this study, 8.1 years 4- 2.6 years post-discon- tinuation of infliximab, P 〈 0.001. The 8 patients who had lost remission after discontinuing infiiximab had a mean number of 5 infusions (range 3-7), with a mean treatment time of 7.2 mo (range 1.5 mo-15 mo). The mean duration of time from the last infusion of inflix- imab to the time of loss of remission was 382 d (range 20 d-701 d). The 6 patients who remained in remission after discontinuing infliximab had a mean number of 6 infusions (range 3-12), with a mean treatment dura- tion of 12 mo (range 3.6 mo-32 too) (P = 0.45 relative to those who lost remission). CONCLUSION: There are no IBD5 or NOD2/CARD15 mutations that predict which patients might have sus- tained remission and which will relapse rapidly after stopping infliximab. 展开更多
关键词 INFLIXIMAB Anti-tumor necrosis factor alpha Crohn's disease Inflammatory bowel disease GENOTYPE
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Elemental Analysis of Soil Phosphorus Neighborhoods Using SEM, Spectral Mapping and GIS
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作者 Kathleen M. Baker Asmare Atalay +1 位作者 Carol Bronick Brodie Whitehead 《Journal of Environmental Science and Engineering(A)》 2013年第8期494-505,共12页
The utility of GIS (geographic information system) methods and spatial statistical analysis on spectral maps of sediment samples were examined. Detailed elemental maps are often constructed using energy dispersive X... The utility of GIS (geographic information system) methods and spatial statistical analysis on spectral maps of sediment samples were examined. Detailed elemental maps are often constructed using energy dispersive X-ray techniques and SEM (scanning electron microscopy). The elemental neighborhood associations of a single element, P (phosphorus), were quantified at a magnification of 3,000 ×. For each of the 170,000 pixels on the images which displayed a strong P concentration, neighborhoods from 0.1μm^2 to 12 μm^2 were examined for associated elemental concentrations. PCA (principal component analysis) revealed two significant neighborhood types associated with P in samples of pH 4, and three neighborhood types at pH 8. These neighborhoods corresponded to Mg-P associations commonly found to be chemically prevalent in river sediments impacted by agricultural operations. Discriminant analysis showed that the greatest accuracy in predicting sample pH could be achieved by using a neighborhood size of 12 ~m2. Potassium at relatively large neighborhood sizes was the element most significant in predicting pH. While many of the chemical associations in close proximity to P could be predicted and explained through mineral solubility, spatial analysis provided some interesting insights into the structure of the samples. Results also indicted differences in the spatial scale associated with different processes. 展开更多
关键词 SEM (scanning electron microscopy) geographic information systems energy dispersive X-ray analysis principalcomponents analysis spatial analysis soil chemistry.
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Critical Success Factors for Executive Information Systems: A Case of Kenyan Organizations
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《Computer Technology and Application》 2012年第4期289-297,共9页
In recent years, a number of organisations have implemented Executive Information Systems (EIS) including Computer-Based Information Systems (CBIS) in order to improve the performance of their executives' jobs th... In recent years, a number of organisations have implemented Executive Information Systems (EIS) including Computer-Based Information Systems (CBIS) in order to improve the performance of their executives' jobs though the majority of executives are unwilling to use EIS applications because of their design defects. Present researches on Executive Information Systems (EIS) are limited and less focused on the factors associated with EIS successful usage. This research adopts an extension of the Technology Acceptance Model (TAM) to derive useful variables to address the problem of the low usage of EIS by executives due to social factors, habits and facilitation conditions variables in Triandis' Framework. It reports on the adoption and usage of EIS by the executives in Organizations. The results show that experience in EIS usage was high with most respondents having used EIS for between 0 to 4 years (72.41%), followed by the 5-9 years group with 25.86%. However, in terms of ability to use EIS, most executives were at the expert (knowledgeable), casual user with 37.93%, followed by novice frequent user group with 31.03%. From this research, the authors propose a model that incorporates the habits, social factors and facilitating conditions in an Executive Information Systems. 展开更多
关键词 EIS (executive information systems) technology acceptance model social factors HABITS facilitating conditions organisations.
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Factors Influencing the Success of Agricultural Information System (AIS): A Factor Analysis
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作者 M. Ahmadvand E. Karami 《Journal of Agricultural Science and Technology》 2011年第1期101-108,共8页
This study aims at investigating the AIS (Agricultural Information System) in Hamedan province, Iran, benefiting from the list of criteria for well functioning AISs that were identified in earlier researches. For th... This study aims at investigating the AIS (Agricultural Information System) in Hamedan province, Iran, benefiting from the list of criteria for well functioning AISs that were identified in earlier researches. For this purpose, a survey method with multi-stage stratified random sampling technique was used to select 31 agricultural researchers, and 62 extension workers in the province. The data were acquired by questionnaire and structured interviews. The instrument for data collection was subjected to pre-testing, validation and reliability tests. The results of the factor analysis revealed that the criteria could be categorized into four overarching groups based on their inter-correlation. The analysis of mentioned criteria in Hamedan province AIS showed less efficiency and effectiveness than studies conducted in other areas. But among these, two desirable criteria existed. It is recommended that the ecological knowledge system (EKS) should be integrated with AIS, and some ecological and sustainable development criteria should be added to the existing ones. 展开更多
关键词 Agricultural Information System (AIS) KNOWLEDGE EXTENSION researchers FARMERS lran
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Denitrification Rates and Their Controlling Factors in Streams of the Han River Basin with Different Land-Use Patterns 被引量:1
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作者 S.P.JUNG Y.J.KIM H.KANG 《Pedosphere》 SCIE CAS CSCD 2014年第4期516-528,共13页
Land-use patterns can affect various nutrient cycles in stream ecosystems, but little information is available about the effects of urban development on denitrification processes at the watershed scale. In the present... Land-use patterns can affect various nutrient cycles in stream ecosystems, but little information is available about the effects of urban development on denitrification processes at the watershed scale. In the presented study, we investigated the controlling factors of denitrification rates within the streams of the Han River Basin, Korea, with different land-use patterns, in order to enhance the effectiveness of water resource management strategies. Ten watersheds were classified into three land-use patterns (forest, agriculture and urban) using satellite images and geographic information system techniques, and in-situ denitrification rates were determined using an acetylene blocking method. Additionally, sediment samples were collected from each stream to analyze denitrifier communities and abundance using molecular approaches. In-situ denitrification rates were found to be in the order of agricultural streams (289.6 mg N20-N m-2 d-1) 〉 urban streams (157.0 mg N20-N m-2 d-1) 〉 forested streams (41.9 mg N20-N m-2 d-l). In contrast, the average quantity of denitrifying genes was the lowest in the urban streams. Genetic diversity of denitrifying genes was not affected by watershed land-use pattern, but exhibited stream-dependent pattern. More significance factors were involved in denitrification in the sites with higher denitrification rates. Multiple linear regression analysis revealed that clay, dissolved organic carbon and water contents were the main factors controlling denitrification rate in the agricultural streams, while dissolved organic carbon was the main controlling factor in the urban streams. In contrast, temperature appeared to be the main controlling factor in the forested streams. 展开更多
关键词 denitrifier communities denitrifying genes nutrient cycle stream ecosystem
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