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1.
地理信息科学中尺度问题的30年研究现状   总被引:1,自引:0,他引:1       下载免费PDF全文
尺度在地学中无处不在,地理信息科学也不例外。自Abler 1987年将尺度列为地理信息的几个重要科学问题之一,30年来,各国学者为尺度问题做了大量的研究工作。试图对这30年的研究作一简单的回顾,明析已解决的部分问题和尚需进一步努力的方向。讨论的重点是Goodchild等提出的5大关键问题,即尺度不变量、改变尺度的能力、尺度效应的度量、尺度作为过程模型中的参数及多尺度方法的实施。通过讨论发现,尺度效应得到了很好的研究,但主要是针对数据尺度,多种尺度(如数据尺度和分析尺度)的联合效应研究仍然严重贫乏;现在有很多转换模型可供使用,但是有些方法的理论基础不够完美;"尺度作为过程模型中的参数"这一问题最任重道远;尺度变换引起的信息量变化缺乏系统研究。这些问题需要引起高度的重视。  相似文献   

2.
In a previous article (Hoffman & Conway, 1989), we reviewed some of the available psychological research that pertains to remote sensing. We focused on two major problem areas: Research on the knowledge of expert interpreters of remotely‐sensed imagery, and research on the use of color in graphic displays. Here, we pursue one of the broad implications of the research ‐ that the field of remote sensing can benefit by incorporating research methods and ideas from experimental psychology. From the experimental psychology viewpoint, “remote sensing”; is actually a misnomer when used to denote a field or area of scientific inquiry. Remote perceiving, as a total process, depends not only on the technology of remote sensing, but also depends critically on the ability of humans to interpret remote sensing displays. This perspective is contrasted with traditional approaches to remote sensing. The discussion involves some ideas about the theoretical and methodological foundations of remote sensing as a unified science.  相似文献   

3.
Geoweb Services for Sharing Modelling Results in Biodiversity Networks   总被引:1,自引:0,他引:1  
Biodiversity researchers in different institutions deal with predictive models for species distribution. These models are useful for biodiversity conservation policies. Species distribution modelling tools need large datasets from different sources and use many algorithms. To improve biodiversity science, scientists need to share models, data and results, and should be able to reproduce experiments from others. This article presents a geoweb service architecture that supports sharing of modelling results and enables researchers to perform new modelling experiments. We show the feasibility of the proposed architecture by developing a set of prototype services, called Web Biodiversity Collaborative Modelling Services – WBCMS. They provide a set of geospatial web services that support the sharing of species distribution models. The article includes an example of a model instance that explains the WBCMS prototype. We believe that WBCMS shows how to set up a cooperative research network on biodiversity research.  相似文献   

4.
提高计算机遥感影像的分类精度,是遥感应用中研究的主要问题之一。作者以规则的形式表示遥感影像解译知识,使用TM影像数据和DEM、坡度、土地利用图等地理辅助数据,从遥感影像处理/地理数据/专家知识一体化的角度出发,使用基于知识的方法进行了研究,改善了分类精度。实例研究证明了方法的正确性。  相似文献   

5.
ABSTRACT

User-Generated Content (UGC) provides a potential data source which can help us to better describe and understand how places are conceptualized, and in turn better represent the places in Geographic Information Science (GIScience). In this article, we aim at aggregating the shared meanings associated with places and linking these to a conceptual model of place. Our focus is on the metadata of Flickr images, in the form of locations and tags. We use topic modeling to identify regions associated with shared meanings. We choose a grid approach and generate topics associated with one or more cells using Latent Dirichlet Allocation. We analyze the sensitivity of our results to both grid resolution and the chosen number of topics using a range of measures including corpus distance and the coherence value. Using a resolution of 500 m and with 40 topics, we are able to generate meaningful topics which characterize places in London based on 954 unique tags associated with around 300,000 images and more than 7000 individuals.  相似文献   

6.
The integrated management of heterogeneous spatial data, such as continuous fields and discrete data, is an important issue for the Geographic Information (GI) community. Indeed, GI users are forced to navigate among and operate with several tools in order to solve their spatial problems, due to the lack of systems capable of integrating different components, each meant to provide a specific solution. The aim of this article is to propose an OpenGeospatial‐compliant solution which supports expert users in handling problems involving heterogeneous data by means of a seamless approach. A class hierarchy modeling spatial discrete objects, continuous data, relationships, and operations, is described, whereby data are organized in agreement with the binary representation. A running example is illustrated to support readers' understanding of the proposed solution. Finally, some guidelines about an implementation modality are given, to demonstrate the applicability of the proposal to an existing DBMS.  相似文献   

7.
Abstract

Today's Geography graduates are employed by a diverse set of employers, and the jobs these individuals fill are as varied as the field of Geography itself. Geographers who join corporate workplace teams may need to find common grounds for communication with their business school‐trained colleagues. This cross‐disciplinary study examines the curricula of introductory courses in Geographic Information Systems (GIS) and one of its business counterparts, Accounting Information Systems (AIS), through an analysis of GIS and AIS textbooks. The findings suggest that there are areas in which shared background exists. Introductory information about systems, and an understanding of database architectures are the most likely areas of commonality; depending on which GIS text was used during the geographer's training, the geographer may also share background in such areas as systems analysis, database management systems, and data modeling.  相似文献   

8.
9.
We review recent psychological research that pertains to remote sensing, with a focus on two major problem areas: The problem of eliciting and characterizing the knowledge of expert interpreters of remotely‐sensed data, and the problem of how to best utilize color in remote sensing displays. This research has immediate relevance to many remote sensing activities, but it also has broader implications. One general implication is that experimental psychology offers concepts and research methods that can be of benefit to the field of remote sensing. It is possible to discover the principles involved in the design of “good”; remote sensing displays, and the design of methods for teaching novices how to interpret remote sensing displays. A second broad implication of the psychological research is that remote sensing, as traditionally conceived, is actually just one part of a larger process of “remote perceiving.”; This idea is pursued in a second article (Hoffman, 1990), in which an attempt is made to characterize remote sensing as a unified science.  相似文献   

10.
Service area research is one of the pivotal topics in Urban Geography. This article first put forward a model of urban population estimation. And on the basis we measured the size and distribution of population in downtown Shanghai, China. The population model was confirmed well by the traditional survey model. Then we extracted a 1-month actual-time data set contains geo-location by collecting in Sina Weibo data, and generated Voronoi diagram by these data which denoted the service patches. We assigned population to each patch. Second part, we proposed a shortest distance algorithm, a minimum time algorithm and an improved p-median algorithm, took advantages of these three methods to divide the service area of metro stations based on patches. Subsequently, we computed the service population in each service area. Last, we took metro line 1 and 2 as examples to research the relationship among 3 location-allocation methods in detail. The results showed that: The spatial distribution of population of the core city in Shanghai emerged a descending trend from center to periphery clearly. All indicators (including area, population, distance and time) in central city within inner ring road have changed little compared with the region between inner and outer ring road. Yet the improved p-median algorithm has a certain effect of optimization. It presented a scientific and rational travel scheme for citizens cost smallest price to select better starting metro station. The study results should contribute to theoretical and technical support for location-allocation of public service facilities.  相似文献   

11.
Civil engineering projects start with intensive site investigations to evaluate the appropriateness of the geographic location to the intended construction. This process is lengthy and crucial to the success or failure of the project. Personnel with multiple skills are required at the evaluation stage, including experts in soil mechanics, geology, surveying, management, structures and meteorology. However, many less fortunate parts of the world lack such expertise and cannot afford it. The main objective of the research described in this paper is to develop an expert system that will use images from different sources to assess sites for civil engineering works. Five engineering applications have been selected for this research. Certainty factors for uncertain or incomplete information are presented. A frame-based expert system is developed and tested in this research. Three different tests have indicated that the system is accurate and promising for site investigations.  相似文献   

12.
作为驱动地表与大气之间能量交换的关键物理量,地表温度在众多领域中都发挥着重要作用,包括气候变化、环境监测、蒸散发估算以及地热异常勘探等.Landsat热红外数据因其时间连续性和高空间分辨率等特点被广泛应用于地表温度反演中.本文详细地介绍了Landsat热红外传感器及其可用的数据与产品的现状,梳理了2001年-2020年...  相似文献   

13.
Several works have been proposed in the last few years for raw trajectory data analysis, and some attempts have been made to define trajectories from a more semantic point of view. Semantic trajectory data analysis has received significant attention recently, but the formal definition of semantic trajectory, the set of aspects that should be considered to semantically enrich trajectories and a conceptual data model integrating these aspects from a broad sense is still missing. This article presents a semantic trajectory conceptual data model named CONSTAnT, which defines the most important aspects of semantic trajectories. We believe that this model will be the foundation for the design of semantic trajectory databases, where several aspects that make a trajectory “semantic” are taken into account. The proposed model includes the concepts of semantic subtrajectory, semantic points, geographical places, events, goals, environment and behavior, to create a general concept of semantic trajectory. The proposed model is the result of several years of work by the authors in an effort to add more semantics to raw trajectory data for real applications. Two application examples and different queries show the flexibility of the model for different domains.  相似文献   

14.
The academic discipline of cartography is a twentieth-century phenomenon. From its incipient roots in landscape representation in geology and the mapping of socio-economic data in geography, it grew into its own sub-discipline with graduate programs, research paradigms, and a scientific literature of its own. It came close to establishing a national center for cartography In the late 1960s. After rather sporadic activity before World War II, the period from 1946 to 1986 saw the building of major graduate programs at the universities of Wisconsin, Kansas, and Washington. Other programs were created, often with the doctoral students from those three. At the end of the twentieth century, cartography underwent significant changes in relation to the emerging discipline of geographic information science. The future for academic cartography is less certain, as graduate programs adjust the balances among the many components of mapping science, including cartography, geovisualization, GI science, GIS systems, spatial analysis/statistics, and remote sensing.  相似文献   

15.
数字工程就是利用数字技术整合、挖掘和综合利用地理空间信息和其他专题信息的系统工程,是一门空间信息科学、计算机科学、通信科学、管理科学与经济人文科学的广泛交叉学科.数字城市是数字工程的典型应用.在概念辨析的基础上,分析了数字城市的认识误区;结合数字工程的基本原理,分析了数字城市的总体工程结构,提出了建设策略.  相似文献   

16.
Spatiotemporal clustering is one of the most advanced research topics in geospatial data mining. It has been challenging to discover cluster features with different spatiotemporal densities in geographic information data set. This paper presents an effective density-based spatiotemporal clustering algorithm (DBSTC). First, we propose a method to measure the degree of similarity of a core point to the geometric center of its spatiotemporal reachable neighborhood, which can effectively solve the isolated noise point misclassification problem that exists in the shared nearest neighbor methods. Second, we propose an ordered reachable time window distribution algorithm to calculate the reachable time window for each spatiotemporal point in the data set to solve the problem of different clusters with different temporal densities. The effectiveness and advantages of the DBSTC algorithm are demonstrated in several simulated data sets. In addition, practical applications to seismic data sets demonstrate the capability of the DBSTC algorithm to uncover clusters of foreshocks and aftershocks and help to improve the understanding of the underlying mechanisms of dynamic spatiotemporal processes in digital earth.  相似文献   

17.
Geographic Information System (GIS) software is constrained, to a greater or lesser extent, by a static world view that is not well-suited to the representation of time (Goodchild 2000). Space Time Intelligence System (STIS) software holds the promise of relaxing some of the technological constraints of spatial only GIS, making possible visualization approaches and analysis methods that are appropriate for temporally dynamic geospatial data. This special issue of the Journal of Geographical Systems describes some recent advances in STIS technology and methods, with an emphasis on applications in public health and spatial epidemiology.The STIS expert workshops were funded in part by grants R01CA092669 and R01CA096002 from the National Cancer Institute, and by grants R43-ES010220 and R44-ES010220 from the National Institute of Environmental Health Sciences. Gillian AvRuskin provided cheerful editorial assistance. We thank the participants at the workshops for providing invaluable expertise and critical insights.  相似文献   

18.
The goal of this research is to design, use and evaluate a set of web lectures, specifically tailored to the needs of students in higher education who follow geographic information system -related courses. Since education in geographic information system includes theoretical concepts and practical experience, both of these teaching strategies will be implemented in the web lectures. The user-centered design approach is used in the design process to increase the acceptance of the web lectures and the motivation to use them: perceived usefulness and ease of use. The results show that the students appreciate the initial set of web lectures, but that they need to be motivated more to use them (especially when theoretical topics are covered). Students still value the “traditional” face-to-face lectures and see the web lectures as an ideal complement.  相似文献   

19.
With the widespread availability of a large volume of urban data, stakeholders from different domains require advanced tools to manage, visualize and understand cities and their evolution. During the last few years, researchers have proposed numerous research works and applications to illustrate the cities of the past and possible scenarios of the future under different conditions. However, many of these approaches are one-time solutions and not based on standards, making them obsolete and unusable for reproducible research. In this article, we present UD-SV: an Urban data-Services and Visualization open-source framework for multidisciplinary research to handle complex processing, analysis, and visualization of urban data. However, our goal is not to present a one-time monolithic software solution for urban data management and analysis, but we demonstrate the design and development of an open and interoperable software framework driven by use cases from diverse users to solve applied research challenges. The main contribution of UD-SV is that it uses open standards and open data with documented and reproducible processes with a particular emphasis on the reuse of existing open-source software components. We also show an enhanced use of standards to enable a shift toward components that are interchangeable or composable with other existing components in the GIS community.  相似文献   

20.
简单面目标与带孔洞面目标间拓扑关系的层次表达方法   总被引:1,自引:1,他引:0  
带孔洞的面目标是现实中较为常见的一类复杂目标,它们之间的拓扑关系要比简单面目标复杂得多.本文基于空间划分和目标分解的思想,利用点集(拓扑学)理论中的邻域概念详细分析和描述带孔洞面目标的点集拓扑分量,这种描述方法实质上是简单面目标点集拓扑分量描述的一种自然延展.进而,对简单面目标间拓扑关系的描述和区分方法进行了扩展,层次地分析和区分简单面目标与带孔洞面目标间的拓扑关系.相比于Egenhofer等人提出的代数描述和间接表达方法,本文提出的方法是一种直接描述和层次表达的方法,并且与简单面目标间拓扑关系的表达方法是相统一的.  相似文献   

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