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  • 2008 Volume 10 Issue 3
    Published: 25 June 2008
      

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  • ARTICLES
    2008, 10(3): 283-283.
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  • ARTICLES
    LIAO Ke, QI Qingwen, CHI Tianhe
    2008, 10(3): 284-290.
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    This paper includes three parts: 1.The Electronic Version of National Physical Atlas of China(ENPAC),edited from The National Physical Atlas of the People's Republic of China,is the second created information product which systematically integrates and vividly displays the spatial information on China's natural resources and environment,and there are some innovations in its developing process.2.Setting up of its system structure and resolving key technologies,including the selection of developing platform,the building of 3D and dynamic data model,virtual map visualization,and integration of multi-source & multi-type data.3.Main characteristics of ENPAC,i.e.,the unique interface structure,the special interactive tools,various types of dynamic maps,special browsing function,vivid virtual 3D relief fly-through,multiple representation,as well as function of analysis and query.
  • ARTICLES
    XU Hanqiu
    2008, 10(3): 294-301.
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    The date and seasonal variations usually result in different atmospheric and illumination effects on the satellite remote sensing images and thus can cause errors in remote sensing applications.Accordingly,pre-processing of multitemporal images using absolute or relative radiometric correction procedures between multitemporal remote sensing images has become critical for reducing radiometric differences.Among various methods,the optimum one is based solely on the digital image and requiring no in-situ field measurements during the satellite overflight.This is achieved through image normalization technique.Taking three pairs of multi-temporal Landsat Thematic Mapper/Enhanced Thematic Mapper plus images as examples,this paper quantitatively compared and evaluated two image normalization models using the criteria of relative noise,root mean square error(RMSE) and slope value derived from the pseudo-invariant feature method.One of the evaluated models is the commonly-used Illumination Correction Model(ICM) proposed by Markham(1986) and Irish(2001).The other model is the Illumination and Atmospheric Correction Model(IACM/IACMt) recently developed by the Remote Sensing and GIS Laboratory of the Utah State University(2004).The results of the comparison and evaluation reveal that,in general,when the seasons and sun azimuth angles of multitemporal images are different or the images have obvious atmospheric effects,the relative noise and the RESE values of the image can be considerably reduced after image normalization,the slopes of scatter plots of the normalized images are more close to 1 when compared with those of unnormalized images,and the seam line between multitemporal images mosaicked using normalized images is almost invisible.However,there is no significant difference between the normalized and unnormalized images when the seasons and sun azimuth angles are similar and the atmospheric condition is also alike.As far as the normalization models are concerned,the IACMt can achieve the best result when the image was seriously atmospherically stained.Nevertheless,the application of the IACMt may sometimes bring noise to the image when the image is free of cloud and atmospheric effect is not serious.This is probably due to the overestimation of the τ value used in the model.
  • ARTICLES
    QIN Kun, XU Min
    2008, 10(3): 302-307.
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    FCM(Fuzzy C-Means) algorithm has good clustering efficiency,therefore it is widely used in the field of image segmentation.But it has the problem of clustering center initialization.Good initial clustering centers will constrain the value function to the overall situation optimal solution rapidly.However,inappropriate initial clustering centers,not only need more iterative times,but also may possibly caused the algorithm finally restrained to the partial optimal solution.Aim to solve the problem of clustering center initialization,the paper proposes a new approach of FCM based on cloud model which is a conversion model with uncertainty between a quality concept expressed by natural language and its quantity number expression.This method in this paper combines cloud model with FCM clustering algorithm,and is applicable in the field of remote sensing image segmentation.It uses the method of cloud transformation to determine the value and number of clustering centers automatically according to the characteristics of the samples,and with less iteration times to reach the optimal solution of the overall situation.The method improves the efficiency of traditional FCM image segmentation of remote sensing image,with excellent stability and intelligence.The paper also chose three remote sensing images of TM to carry out image segmentation experiments using the methods of cloud model based FCM,and compared it with the traditional FCM method.Experimental results prove that by using our method we can reduce the iterative times and enhance the efficiency of Fuzzy C-Mean clustering algorithm.
  • ARTICLES
    WANG Min, JIANG Sheng, YANG Xiaomei
    2008, 10(3): 308-313.
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    Texture is one kind of important feature for information extraction or target recognition from high spatial remotely sensed imagery.In this paper,a Gabor filtering based method to recognize residential areas from remotely sensed imagery is proposed based on that it often takes on obviously directional textures of the rural residential areas on the panchromatic imagery of the Beijing-1 micro-satellite system.Part of the Gabor filtering method includes the following steps: 1)to extract multi-scale,multi-oriented texture features with the Gabor filter group,2) to rectify and smooth the features with feature filtering;and 3)to segment the image with k-means clustering.With these steps,the initial residential areas can be extracted but with many deficiencies which include the existence of interspaces,holes and useless patches within many residential areas mainly because they are only obtained with image clustering.To resolve these problems,a morphological scale space based method is used to dissolve these residential patches with iteratively enlarged closing operators.Firstly,a pair of closing,opening operators are used to remove all the noises.A scale space is then constructed by using closing operator with structuring elements of increasing size.By doing so,the connected components(the set of pixels with neighborhood relationships) in the image will merge into each other gradually and become a single cluster in the end.This is essentially a binary image segmentation process,and can also be treated as a hierarchical clustering. The final number of clusters is the one which survives(relatively,not absolutely) the longest scale range,and the clustering which first realizes this number of clusters is the most suitable segmentation.Several experiments are carried out to validate the method,which includes the comparison to the classical texture analyzing method of co-occurrence matrix.
  • ARTICLES
    REN Hongyan, ZHUANG Dafang, PAN Jianjun, QIU Dongsheng
    2008, 10(3): 314-319.
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    Increased heavy metal concentrations in cropland soil cause stress on many crops and decline crops′ quality.The objective of this article is to try a new method to monitoring heavy metal pollution in cropland like remote sensing,which can be applied to estimate Pb pollution on paddy plant. Experiment that paddy plants were cultivated in the potted soils manually contaminated by Pb was settled down to investigate the stress caused by Pb absorbed by paddy plants.In the developmental stages of seeding,early tillering,full tillering,jointing and booting,hyperspectral reflectance measurements on paddy plant canopy were done by a hyperspectral radiometer.Meanwhile,we got Pb concentrations in parts of paddy plant,and canopy leaves′ chlorophyll content.Quantitive relationship between Pb concentration in parts of paddy plant,canopy leaves′ chlorophyll content and canopy reflectance was studied.Results showed that chlorophyll content of canopy leaves and composition of chlorophyll,chlorophyll a and b vary obviously under Pb stress.The difference of canopy reflectance at the sensitive bands of 520nm~560nm and 630nm~690nm is most significant,and it differs from the three Pb treatments on rice from each other.Therefore,these spectral regions are validated as sensitive bands to Pb pollution on paddy plants.According to the first(620nm~670nm) and forth channel(545nm~564nm) of MODIS and sensitive band(760nm) in the near infrared region,552nm,672nm and 760nm were selected to construct composite normalized difference pollution index(CNDPI).CNDPI discriminates all the three Pb contamination levels of paddy plants.At the early tillering stage,the canopy hyperspectral reflectance and CNDPI distinguish Pb pollution condition commendably.Therefore,monitoring Pb pollution on paddy plants with remote sensing data of raw canopy reflectance and CNDPI at the early tillering stage is a potential solution and new reference for heavy metal pollution condition monitoring technology.
  • ARTICLES
    QIAO Yuliang, WU Mingquan, WANG Dong
    2008, 10(3): 320-325.
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    Using TM and ETM image,we did a dynamic monitoring about coal resources of Xiangning County.In the remote sensing image,we rely on its texture,color,contrast and shape to distinguish Geo-object.Due to its low visual effect,we should do some data preparation.Refering to multi-statistical analysis,the best band combination is 4,5,3.Because of other Geo-objects interference,it's far from prefect,so we should do some enhancement.Through PCA transformation,useful message is increased and influences of mountain shadow are eliminated efficiently.Then,we did the supervised classification treatment and compiled a distribution map of coal resources of Xiangning.Next,we used GIS's overlap and statistical function and got the number of mines.Above all,this paper discusses the differences between mining and closed.The image reflects different intensityies.The closed mines have a high bright color.This experiment proves the availability to use remote sensing to monitor coal resources.This method is economical,efficient and can be applied in environmental protection and mining.
  • ARTICLES
    CHEN Zhiqiang, CHEN Jianfei
    2008, 10(3): 326-331.
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    With Fuzhou and Taipei serving as study regions,comparative analysis serving as study method,ASTER and TM serving as data sources,the study extracted green land information and calculated landscape indexes of urban cores in Fuzhou and Taipei.The results showed that:both areas of urban cores,green lands and their area percentages increased while there was an increase in land use of town and a decrease of green land area percentage in Fuzhou;and the change tends are almost the same in patch shape,connectivity and aggregation in the two regions while there was simpler patch shape,higher connectivity and aggregation in Fuzhou in 2004 than those in Taipei in 2003.
  • ARTICLES
    ZHOU Xiaocheng, WANG Xiaoqin, WU Bo, LI Huiguo
    2008, 10(3): 332-337.
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    The application of remote sensing technology to the monitoring of urban sprawl has become an important field of study.This paper presents a general method using remote sensing technology to monitor urban sprawl by taking Zhangzhou city in Fujian Province of China as a case.First,for ASTER remote sensing image,the built-up land can be extracted effectively and exactly by combining knowledge from unsupervised classification,multi-temporal vegetation index and terrain distribution of urban built-upland.The precision is over 90%.Secondly,for TM remote sensing image,this paper presents a scheme to improve the method for extracting the built-up land which was raised by Xu Hanqiu.The scheme combines temporal and spatial knowledge of the built-up land with Xu's method.The result shows that the precision of the built-up land,with a precision exceeding 90%,satisfies the demand for analyzing changes in urban sprawl.
  • ARTICLES
    SUN Deyong, LI Yunmei, LE Chengfeng, WU Lan
    2008, 10(3): 338-343.
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    With urban development,the quality of eco-environment in city is being paid more and more attention.This paper takes Nanjing city as an example.On the basis of analyzing TM image in 2000 and CBERS-2 image in 2004,the land cover information in different years can be extracted by man-machine interaction.The result of analysis of the variations of land covers and eco-environment show that in 2000,the main parts of land use are residential area,paddy field and dry land while in 2004,the main parts are residential area,dry land and woodland.The paddy field reduces greatly and the inhabitant area increases obviously.The main parts of change in land use types are paddy field and dry land.In terms of changing rates of land covers,paddy field and transportation land change most quickly,and their dynamic degrees are-8.61 and 5.17.The different category changes are complex,and 20 pairs of transformation relations exist in eight major classes(except naked rock).The values of EV in these two years have been computed,being 0.3871 and 0.3799.The results show that eco-environmental quality in Nanjing is descending slightly.Moreover,biological abundance index increases by 10.43,indicating that the biological diversity changes a lot positively during four years.Vegetation cover index decreases by a big margin,indicating that the vegetation cover reduces obviously.
  • ARTICLES
    TANG Liyu, CHEN Chongcheng, CHI Ziwen
    2008, 10(3): 344-349.
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    Collaborative Forest Fire Fighting Decision-Making experts may come from different organizations or different fields,having different knowledge structure and preferences,which gravely hinders the effective communication in the decision-making group.In this paper,ontology was introduced in Collaborative Forest Fire Fighting Decision-Making to solve semanteme compatibility during collaborative decision-making procedure.The prevalent construction methods of domain ontology were analyzed.According to the accomplished methods and in light of engineering method and life cycle approach in software development,the construction method of forest fire ontology was presented,which includes three phases of specification,conceptualization and formalization.Taking forest fire fighting decision-making application as an orientation,according to the analysis of decision-making content and the discussion among domain experts,based on the classification system and combined structure of conception,modeling primitives including concepts,relations,functions,rules,etc were abstracted from relative fields such as forestry,meteorology,fire fighting,and geography,and shareable,comprehensible,reusable,and conception models were built.Forest fire fighting domain ontology was built with ontology modeling tools. Parsing and visualization tool of ontology was designed and developed,Semantic Network Graphic and tree diagram visualization approaches were applied to the tool,with which users can display the relationship of conceptions(such as the inheritance relationship,the relationship of classes and instance and the relationship of classes and property et al.) by realistic visualization fashion and query connotation of them.The result of research serves as a basis for the communication between different disciplines or domains for effective cooperation.That would provide a reference for study on forestry and fire fighting informatization,would provide an important way in semantic level for forest fire management and the emergency demand decision-making.
  • ARTICLES
    YANG Liuyong, CHEN Lihui, LOU Huixin
    2008, 10(3): 350-356.
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    The research of imports of foreign direct investment(FDI)on the host country's economic growth is an issue in the study of international investment and economic growth.Along with the increase of FDI in our country,the evidence from China plays an important role to deepen the study in the field.In the paper,based on the data from different provinces and different areas(Eastern,Middle and Western Areas) from 1992 to 2004 in China,we use a modified De Mello's model to improve the robust city of the results.Like other similar studies,our research proves that FDI have a positive effect on China's economic growth.But at the same time,our research distinguished from others in that it shows FDI's different impact on Eastern,Middle and Western Areas.Compared with Middle Area,FDI's impact on Western Area is statistically lower,which means Western Area should reform its investment environment to improve the FDI's efficiency.Regression results also show that compared with Middle Area,FDI impact on Eastern Area isn't significantly higher.While such result is a little bit perplexing,it may reveal FDI's "crowd out" effect in the Eastern Area.
  • ARTICLES
    JIANG Hailiang
    2008, 10(3): 357-362.
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    Difference between plantation area and farming area of the design form and field form in the second countrywide farming survey is mainly caused by the difference of survey targets,survey time,sites selection,statistical calibers and technological measures.Differences also arose from the fact that investigators poorly comprehend the relationship among ownership,right of use and right of operation and can't distinguish farmer contract ration field,large foodstuff family and farming produce department contract plantation and land exchanges between farmers.The paper also listed many factors which may lead to the plantation area difference in the countrywide farming survey,such as land whole expropriation,land part expropriation,land void expropriation,land expropriation in advance,mass plantation occupied for city use,land consolidation,land protection and balance of occupation.
  • ARTICLES
    XU Jun
    2008, 10(3): 363-369.
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    People usually use qualitative terms to express spatial relations,while current geographic information systems(GIS) all use quantitative description to store spatial information.The abilities of current GIS to represent spatial information about geographic space are limited,and it is inconvenient for GIS users without professional training.The next generation of GIS could be intelligent GIS built on Na1¨ ve Geography.It will act and respond as a person would,and therefore can be used without major training by new user communities to solve day-to-day tasks.In order to bridge the gap between natural-language terms and the computational model of spatial relations,a complete understanding of the relationship between the ambiguous natural-language representations and the geometric spatial relations of geographic objects is requisite.A human-subjects test was conducted to find out how natural-language descriptions of spatial relations of linear objects are determined by the geometric configurations of the objects.A series of maps,with each map showing two linear geographic objects,were displayed to the human subjects,and a sentence describing the spatial relations of the two objects was provided to the subjects.Comparing the sentence to the map,the participants determined whether this sentence described the relation correctly,and chose their agreement from given options ranged from "strongly agree" to "strongly disagree".The answers chosen by the human subjects were converted to agreement degrees which represent the plausibility that certain spatial relations can be described by the spatial predicates,so the results could be analyzed quantitatively.The results indicated that both topology and metric properties influent people on choosing spatial predicates to describe spatial relations,but they have different effects on various spatial predicates.Some spatial predicates are mainly affected by topological relations,while metric measures do not have significant effects.Other spatial predicates are primarily affected by topology metric details,while topology only has secondary effects on them.The categories of geographic entities were also found to have effects on the natural-language description in some cases.
  • ARTICLES
    WEI Wenxia, WANG Yanzhen, CHEN Xiuwan, JIANG Miao, LI Liping
    2008, 10(3): 370-376.
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    Ecological sensitivity evaluation has practical significance and scien.tif 95% 93% ic values for territorial ecological environmental rehabilitation.Under the support of Remote Sensing and Geographic Information System,we use ETM images of 2004,map of soil distribation characteristics and other related geographic information,and select the soil types,vegetation covering degree and land use status quo as the major evaluation factors.We adopt analytic hierarchy process(AHP) to confirm every factor weight;then we built the evaluation model and evaluate cropping-pastoral interlacing region taking Duerbete County,which is a representative area,as an example.There are three types of ecological sensitivity districts in Duerbete County.It is concluded that the low-grade ecological sensitivity areas are the wetland and lake ecological system,including good status grassland.Its resistibility against natural calamityies is strong.The intermediate ecological sensitivity areas are cropland and grassland complex system.It has some ecological recreative ability.The high ecological sensitivity areas are sand,cropland,sand,grassland and the salina ecological system,whose self-adjustive ability is weak with poor relative stability.The study shows that Remote Sensing for data collection and Geographic Information System for spatial analysis are two important tools in the ecological sensitivity evaluation practice.The result is reasonable and credible and can support ecological rehabilitation.
  • ARTICLES
    MA Weifeng, WANG Xiaorui, ZENG Zhongping, XUE Chongsheng
    2008, 10(3): 377-381.
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    Along with the multi-scale digital elevation model (DEM) accomplished in China,the DEM-based spatial analysis plays an increasingly important role in GIS research,and the DEM-based spatial analysis needs high resolution data,which means the increasing demand for density computing.Computational grids can solve the high density computing demand for DEM analysis that involved enormous amounts of data.We demonstrated the feasibility of DEM analysis tools and completed the prototype of the system based on computational grids and designed system architecture based on Alchemi,which is a computational grids framework.The DEM analysis tools can be divided into DEM analysis server,computational grids nodes and spatial database server in architecture.The DEM analysis tools can be implemented in API,grids,spatial analysis and application layers.The Parallel algorithm of the tools is based on the principle of procedure decomposition,functional decomposition and data decomposition.A separate spatial database server is designed as a spatial data server to avoid huge decline in efficiency caused by the mass data transfer in distributed computing grid.The efficiency of computational grids is tested by slope factor calculation based on the prototype system of DEM analysis tools.Experiments show that the efficiency of DEM analysis for big dataset can be significantly enhanced by computational grids,but for small dataset,the efficiency is not significant.The results confirm the feasibility of the application of computational grids to DEM spatial analysis for enormous amounts of data.
  • ARTICLES
    YANG Hui, SHENG Yehua, WEN Yongning, HU Ying, WANG Jia, YANG Yi
    2008, 10(3): 382-389.
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    There are lots of geo-analysis model resources in the Web.However,the heterogeneity of these existing models has limited their sharing and reuse.Though the mature network technology can provide strong support to the sharing and reuse of the heterogeneous geo-analysis models,the study of geo-analysis models is relatively stagnant.On one hand,the standard of the metadata for models still hasn't formed.On the other hand,the semantic heterogeneity exists in spite of following an united standard.In order to meet the needs of the development of heterogeneous geo-analysis models,this paper proposes a method to standardize and formalize the existed heterogeneous geo-analysis models.Firstly,based on the status of the metadata for the geo-analysis models, this paper designs a standard framework of metadata for the geo-analysis models and makes use of XML Schema to describe this standard framework,which satisfies the standardization in the syntactic and structural level.The standard framework is comprised of section,compound element and data element.The data element is the basic unit to build the framework,and it can be described by several attributes.The compound element is made up of the data elements and the other compound elements.The section is the aggregation of related compound elements and data elements.Secondly,it presents a semantic mapping model on the basis of ontology because of the limitation of XML Schema in semantics.XML Schema is good at describing the structure of the XML document,while ontology places emphasis on the expression of semantic information.The domain ontology includes the concepts of the domain and the relations between the concepts,which are called the sharing ontology in this paper.For metadata for geo-analysis models,the local ontology will be built according to the sharing ontology.At the same time,the different words in the two metadata documents which in fact express the same concept will be identified through respective local ontology.This model applies ontology to express the formalization of metadata for geo-analysis models,which eliminates the semantic heterogeneity between metadata for models.Finally,the paper takes the application "Sharing Portal of Geo-analysis Model" as an instance to validate the method mentioned above.The application realizes the architecture of standardization and formalization of heterogeneous geo-analysis models and proves this architecture is helpful to share and reuse the heterogeneous geo-analysis models.
  • ARTICLES
    FU Shifeng, ZHA Xuan
    2008, 10(3): 390-395.
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    Non-point source pollution is a major cause for water pollution.Sediment is a type of pollutants and the carrier of nutrient,so predicting soil erosion would provide exact information for making environmental planning and taking measures.The GIS software including Arc/Info,Mapinfo and the RS software PCI Geomatica made up the technology platform for the research,on which spatial database and non-spatial database were built,hydrological processes simulation and watershed subdividing were performed.Reasonable methods were adopted to obtain R,L,S,K,C and P factors values.Soil erosion was predicted and risk areas of soil erosion were identified in Dongzhen Watershed.According to the analysis on the affecting factors of SDR,founding on former equation,this paper added hydrological factor to SDR equation and built a SDR equation for Dongzhen reservoir watershed,which included underlying surface factor and hydrological factor.Finally,calculating results of soil erosion quantity were proved credibly by using SDR equation for Dongzhen Watershed and monitoring data of sediment.Results showed annual average soil erosion amount was 916.32 t/km2,falling in to the category of light-grade erosion.The gentle and light-grade erosion area amounted to 93.82%;other grades occupied only 6.18%,but contributed 45.21% of sediments to the watershed.
  • ARTICLES
    FANG Li, ZHONG Ershun, YAO Min
    2008, 10(3): 396-400.
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    It's a good mode and trend for customer service center of banking to use WebGIS based technologies to provide positional information services.Design methods of system architecture and functions of customer service system of banking based on WebGIS are proposed in this paper.A system instance is presented with functions of basic map operations,editing and maintenance bank information,complete query functions and statistical analysis.The system is powered by SuperMap IS.NET which is a technologically advanced WebGIS development platform to provide positional services.SuperMap IS.NET has characteristics of manipulating large data,integrating multi-source data and clustering servers.Besides this,it has strategy and technique of multi-process and multi-threading,and provides multi-level cache mode,which increases systematic customer concurrent access capacity,and shortens the average response time of the system.So the customer service system of banking based on SuperMap IS.NET can respond quickly to the client requests.In comparison with the old mode that service personnel provide location service to customers by memory and looking up paper maps,using this system can improve service efficiency and quality.In addition,the system can record all the query information such as where customers are located,which bank outlets are intended to.This information can be used for statistical analysis to find out whether the distribution of the bank outlets is sensible,or to aid in decision making for a new bank location.
  • ARTICLES
    WANG Cunmei, FENG Bin, CHEN Xinxia, LIAN Baoquan, YAO Xin, YANG Wenxing, GU Weiwei, DENG Xiaohui, ZHAO Lidong, WANG Ping
    2008, 10(3): 401-407.
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    Along with the widespread application of radioactive substance in the domains of industry,agriculture,medicine,resources,environment,military and so on,universal concern has been put on the problem of radioactive resource pollution.Therefore,the environmental protection departments need an effective tool for supervising and managing the radioactive resource of the area.Based on the technologies such as Remote Sensing(RS),Geographical Information System(GIS),Globe Positioning System(GPS),Database and Communication,this research developed an application system for radioactive resource supervising and management,including both an enterprise edition and a government edition.The central system is located in the information center of environmental protection bureau,and the subsystems are located in the radiation department of environmental protection bureau and other related departments,inform a graded and distributed computer network communication and management system.The system can achieve the functions such as radioactive sources location and video monitoring and alarming,radioactive resources′ information management,map management,spatial analysis,system tools.The system has already been used in Jiaozuo Environmental Protection Bureau,and the successful application there indicates that the system which integrated spatial information can meet the needs of radioactive sources management nowadays and supply a more effective and reliable technology solution for radioactive resources monitoring and management.At the same time,this project can enhance the processing ability of emergency,and play an important role for protecting civil health and social stability.