Vector Geographic Information Research Articles

A traffic state prediction method based on spatial–temporal data mining of floating car data by using autoformer architecture

AbstractFloating car data (FCD), characterized by wide spatiotemporal coverage, low collection cost, and immunity to adverse weather conditions, are one of the key approaches for intelligent transportation systems to obtain real‐time urban road network traffic information. The research aims to utilize GPS data from taxis in Shanghai and vector geographic information data of the road network, with urban expressways as the research focus. Based on the different driving characteristics of expressways and the vehicles on the ramps below, a clustering analysis is employed to determine all floating vehicles traveling on the target road. Furthermore, an adaptive buffer zone consistent with the road orientation is established based on road vector geographic data. This allows for the extraction of FCD within segmented areas, and the average vehicle speed for that road segment is obtained through weighted calculations. This method fully exploits the natural characteristics of taxis in urban areas with a wide spatiotemporal distribution. The data effectiveness and coverage reach 90.2% and 85.7%, respectively, significantly surpassing the traditional grid‐based extraction method for FCD. Additionally, to capture the long‐term spatiotemporal dependencies of road network traffic states, a spatial–temporal autoformer (STAF) network based on spatial–temporal sequence autocorrelation is employed for traffic state prediction. The results indicate that the STAF method demonstrates good performance in medium‐ and long‐term prediction. We believe that the proposed FCD mining method in this paper provides a new approach for efficiently extracting large‐scale road network traffic states and conducting medium‐ to long‐term predictions.

Representing Vector Geographic Information As a Tensor for Deep Learning Based Map Generalisation

Abstract. Recently, many researchers tried to generate (generalised) maps using deep learning, and most of the proposed methods deal with deep neural network architecture choices. Deep learning learns to reproduce examples, so we think that improving the training examples, and especially the representation of the initial geographic information, is the key issue for this problem. Our article extracts some representation issues from a literature review and proposes different ways to represent vector geographic information as a tensor.We propose two kinds of contributions: 1) the representation of information by layers; 2) the representation of additional information. Then, we demonstrate the interest of some of our propositions with experiments that show a visual improvement for the generation of generalised topographic maps in urban areas.

Blockchain technology for vector geographic provenance information organization and verification

Blockchain technology for vector geographic provenance information organization and verification

Local Path Planning of Driverless Car Navigation Based on Jump Point Search Method Under Urban Environment

The Jump Point Search (JPS) algorithm is adopted for local path planning of the driverless car under urban environment, and it is a fast search method applied in path planning. Firstly, a vector Geographic Information System (GIS) map, including Global Positioning System (GPS) position, direction, and lane information, is built for global path planning. Secondly, the GIS map database is utilized in global path planning for the driverless car. Then, the JPS algorithm is adopted to avoid the front obstacle, and to find an optimal local path for the driverless car in the urban environment. Finally, 125 different simulation experiments in the urban environment demonstrate that JPS can search out the optimal and safety path successfully, and meanwhile, it has a lower time complexity compared with the Vector Field Histogram (VFH), the Rapidly Exploring Random Tree (RRT), A*, and the Probabilistic Roadmaps (PRM) algorithms. Furthermore, JPS is validated usefully in the structured urban environment.

An agent-integrated irregular automata model of urban land-use dynamics

Urban growth models are useful tools to understand the patterns and processes of urbanization. In recent years, the bottom-up approach of geo-computation, such as cellular automata and agent-based modeling, is commonly used to simulate urban land-use dynamics. This study has developed an integrated model of urban growth called agent-integrated irregular automata (AIIA) by using vector geographic information system environment (i.e. both the data model and operations). The model was tested for the city of San Marcos, Texas to simulate two scenarios of urban growth. Specifically, the study aimed to answer whether incorporating commercial, industrial and institutional agents in the model and using social theories (e.g. utility functions) improves the conventional urban growth modeling. By validating against empirical land-use data, the results suggest that a holistic framework such as AIIA performs better than the existing irregular-automata-based urban growth modeling.

Locally weighted linear combination in a vector geographic information system

Weighted linear combination is a multi-criteria decision analysis technique that can be used by decision-makers to select an optimal location from a collection of alternative locations. Its local form takes into account the range of attribute values within a user-defined neighbourhood in accordance with the range-sensitivity principle. This research explores locally weighted linear combination in a vector-based geographic information system. A custom application in ArcGIS 10 allows the user to select a neighbourhood definition from a standard set including contiguity, distance, and k-nearest neighbours, for which local weights are generated. A case study on vulnerability to heat-related illness in Toronto is used to illustrate the technique. The impact of local weighting on the heat vulnerability index is examined using visual analysis of the spatial patterns of heat vulnerability under the global and local approaches, as well as the sensitivity of the local approach to the selected neighbourhood definition. A trade-off analysis of the local weights is also presented. The combination of socio-demographic and environmental determinants in a locally weighted index results in patterns of heat vulnerability that could support targeted hot weather response at a micro-geographic level within urban neighbourhoods.

Meaningful image objects for object-oriented image analysis

Image objects obtained by segmentation usually provide a much more reliable representation of real world objects than individual pixels. However, in regions with high quality spatial information, image analysis should focus on objects of interest rather than artificial image objects. A simple method for applying this object-oriented approach consists of converting existing vector geographic information system (GIS) data into raster objects. A problem with this method is that it may produce image objects with saw-toothed edges which barely match measured objects boundaries. In order to address such a problem, a method for adjusting boundaries of image objects is proposed. The new method uses a vector square grid for pixel representation. Vector-based image objects exhibit boundaries which better reproduce the shape and appearance of GIS objects. The proposed approach was applied to extract geometric and biophysical properties of agricultural plots from remotely sensed imagery. Results suggest that vector-based image objects provide much more accurate values than raster-based image objects.

Implementation of Airborne Remote Sensing Route Design System

Route design is an important part of airborne remote sensing. On the basis of DEM, using raster and vector geographic information, designing aerial route quickly and accurately is the main target of this system. Considering the actual requests, this system formulates two modes of aerial route design methods: according to navigating area and two points to design. This paper mainly introduces functions of system and algorithms of aerial route design methods.

Calculation of average skidding distance on sloping terrain with GIS tools

To determine skidding productivity and costs for skidding operation, it is necessary to estimate real skidding route and to calculate average skidding distance. This study was intended to expose how the real average skidding distance was to be calculated and which operation process was to be followed up for harvesting units/blocks having irregular shapes as three dimensions. Compartments, harvesting stands, were divided into sub-compartment polygons called harvesting blocks with respect to transport borders determined according to road location, stream flow, and topographic structure of mountainous terrain. To calculate average skidding distance based on surface length between the most suitable existing road segments and centroids of the polygons, a selective process was followed. In this study, vector and raster Geographic Information System (GIS) tools were used. To compare with other approaches and evaluate of the calculus algorithm, various skidding distance determination strategy were improved and applied on the same test area. In this study, spatial analyses have been made for 17 compartments selected from Pamucak Forest Planning Unit of Isparta Forest Region, in Southern of Turkey. According to the results the mean difference between real average skidding distance (ASDR) and shortest average skidding distance (ASDS) was found amount 24 meters for the test area. It has been considered that the ASDR amount calculated in this study is too close to real skidding distance used for harvesting operations. Keywords: Average skidding distance, Transport boundary, GIS, ArcHydro tool

A Map Overlay Error Model Based on Boundary Geometry

An error model for quantifying the magnitudes and variability of errors generated in the areas of polygons during spatial overlay of vector geographic information system layers is presented. Numerical simulation of polygon boundary displacements was used to propagate coordinate errors to spatial overlays. The model departs from most previous error models in that it incorporates spatial dependence of coordinate errors at the scale of the boundary segment. It can be readily adapted to match the scale of error–boundary interactions responsible for error generation on a given overlay. The area of error generated by overlay depends on the sinuosity of polygon boundaries, as well as the magnitude of the coordinate errors on the input layers. Asymmetry in boundary shape has relatively little effect on error generation. Overlay errors are affected by real differences in boundary positions on the input layers, as well as errors in the boundary positions. Real differences between input layers tend to compensate for much of the error generated by coordinate errors. Thus, the area of change measured on an overlay layer produced by the XOR overlay operation will be more accurate if the area of real change depicted on the overlay is large. The model presented here considers these interactions, making it especially useful for estimating errors studies of landscape change over time.

Modelling geographic data with multiple representations

The impact of resolution has been widely studied on raster data, exploring new ways to store and use raster data at different resolution levels. A similar amount of work has not yet been achieved for vector data. The aim of this paper is to propose a framework suitable for vector data for use at different resolution levels. The framework has in fact a wider scope as it has been designed for the general problem of using multiple representations of geographical and thematic data. This problem can be divided into three main issues: data modelling, data matching from different data sets, and data utilization. How can geographical phenomena with several representations be modelled in vector geographic information systems (GIS)? How should different representations be matched to make the data-management systems aware that they all represent the same geographical phenomenon? How can systems supporting multiple representations be used? Answers to these questions have been elaborated as part of the European MurMur project. They are presented here and illustrated using current applications from the French national mapping agency (IGN).

Malaria on the World Wide Web.

The Internet is enabling scientists and clinicians in areas with endemic malaria to transfer information to scientists and clinicians in other countries. This should allow changes in therapy to follow the rapid changes in the disease that have posed such difficulties in the past. This article reviews Internet resources that focus on malaria. This includes 90 Web sites in 12 sections. Authoritative multinational organizational sites and regional sites, such as those in Africa, Asia (including Thailand and India), and South America (in Venezuela and Brazil), are described. Basic research-oriented databases, such as those that deal with plasmodia genomics, biochemistry, and vaccine development, as well as vector information and geographic satellite information systems, are reviewed. There is a section about malaria research-funding organizations that offer online applications. Useful teaching resources and journals, including those with full online access, are detailed.

Modelling road surface sediment production using a vector geographic information system

Field investigations indicate that unpaved roads are the largest sediment source on St John, US Virgin Islands. Crosssectional measurements of eroded road surfaces were used to establish an empirical relationship to predict annual road surface erosion as a function of road gradient and contributing drainage area. A model (ROADMOD) for estimating and mapping average annual sediment production from a road network was developed by combining this empirical relationship with a series of network algorithms to analyse road data stored in a vector geographic information system. ROADMOD was used to estimate road surface erosion in two St John catchments with very different road densities but similar land cover, topography and soils. Unpaved roads were found to increase sediment production in the more densely roaded catchment by a factor of three to eight, and in the less-roaded catchment by a factor of 1.3-2.0. Turbidity measurements in the receiving bays of these two catchments are consistent with model predictions and observed sediment delivery processes. Although this model was developed specifically for St John, it can easily be adapted to other locations by substituting a locally derived predictive equation for road erosion. Model assumptions, limitations and potential improvements are discussed. @ 1998 John Wiley & Sons, Ltd.

Landscape context of rural residential development in southeastern Wisconsin (USA)

Private on-site sewage systems serve residential development in rural landscapes throughout the United States. In the State of Wisconsin, three major types of private sewage systems facilitate residential development on sites that span gradients in slope, soil permeability, depth to bedrock, and depth to water-table. Conventionalsoil-absorption sewage treatment systems are constructed on sites with minimal physiographic constraints; more highly engineered alternative sewage treatment systems are installed on sites with moderate to severe constraints; holding tanks provide no on-site sewage treatment and are employed on sites with the most severe physiographic limitations. An environmental impact statement (EIS), prepared in 1979 on the proposed widespread use of alternative private sewage systems, suggested that alternative systems might facilitate in-fill development on poor sites near existing cities and lead to compact, higher density development patterns. The research reported in this paper tested the validity of this EIS scenario by comparing development patterns associated with a sample of conventional systems, alternative systems, and holding tanks installed during the 1980s in Ozaukee County, Wisconsin. Land use data, soils data, and other site attribute data were assembled and analyzed in a vector geographic information system (GIS). Because each type of private sewage system has a unique set of siting criteria, the three sets of sampled systems are located in significantly different physiographic regions within the County. Collectively, installations of all three systems facilitated scattered residential development throughout the rural landscape. This development consists of relatively small residential patches dispersed within an agricultural matrix. Wastewater management technology, if not constrained by public policies or other socioeconomic factors, can be an important anthropogenic factor influencing both the process and pattern of landscape change.

Accessibility in the European Union: the impact of the trans-European road network

The aim of this paper is to assess the impact of the future Trans-European Road Network as far as accessibility is concerned. Accessibility analysis and presentation of results is undertaken using a vector geographic information system (GIS). In accordance with the results of the study, the new planned links appreciably modify levels of accessibility to economic activity centres, thus reducing distances and bringing the peripheral regions closer to the central ones. In accordance with the analyses carried out, the benefits of these new infrastructures will affect the whole of the territory of the European Union, albeit particularly so in the peripheral regions.

A parallel intersection algorithm for vector polygon overlay

A parallel intersection algorithm for speeding the creation of a composite network of polygons whose identities relate to the original polygons from which they are formed in vector geographic information systems (ISs) is described. The algorithm reduces unnecessary intersection checking, especially when polygon density is high. Single-stream and multiple-stream versions of the algorithm are discussed. Experimental results illustrating the overall performance of the parallel algorithm are presented.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>