A Research Of Computable Models On Location Analysis

Location analysis is very important in geography. As a branch of location, Facility location is now an important topic in research field. The traditional location analysis in geography is most in macro-scale and qualitative analysis, but facility location is most in micro-scale and quantitative analysis. It is an inevitable trend of connection of facility location with geographic information system, special spatial analysis.In this paper, we classify the facility location into three kinds. They are 1) Insert new facility 2) Network facility location 3) Voronoi diagram and facility location. On the basis of these models, we research the algorithm and implement them.Firstly, we classify Insert new facility with existing one competitive facility and existing more than one competitive facility. When there is only one existing competitive facility, the request distribute among the facilities according to an exponential function. We develop an iterative algorithm to calculate the new facility's coordinate. In the test, the facility's coordinate are convergent gradually, so we get the best location.We use the classical operational research models and introduce the GIS spatial data models into the operation research models. Location is a spatial conception, so facility location can not be solved without spatial data model. Spatial analysis has been the weakness of GIS for a long time, facility location as an implementation of spatial analysis improves the spatial analysis ability of GIS. The models propose in this paper is very useful and can be used in many fields.Then we process the demand analysis, which is one of the most important works of developing system, on the basis of software engineering theories. We propose that models are the core of the entire system, which are basis of the algorithm and the data structure. We amend the GIS demand analysis of Wang et al (1993), and propose that the demand analysis should consider the objective and the geographical principle. Before develop the system, we analysis the character of the users. So the software we develop can match the users demand.We use the mature algorithm to implement the models, so the reliability of software is very good. The reliability and the stabilization is important character of the software. The new algorithms should be tested for a long period for its reliability, so develop new algorithm is not suitable. The computation of facility location belongs to NP hard problems, so it is difficult to solve its calculation of large scale. We use the heuristic algorithm to solve this problem. So the design of the algorithm matches the aim of the system.We design the system on the basis of the demand analysis. We pursue a friendly user interface, so we use the traditional Windows interface. And we adopt the visual program language Delphi and GIS tool MapObjects to develop the software. At last, we design the facility models on the basis modularity, so the software can be expanded and reused easily.Finally, on the basis of insert new facility model, network facility location model, Voronoi diagram model, we use Delphi and GIS controls Mapobjects which based on ActiveX technology to develop facility location software.The facility location software can be used to analysis the location problems in our lift. We use the software to analysis the location of retail store, garbage, emergency facility, bank et al. Because of the property of the facilities is variable, so we use the correspond models to solve the problem.