Geographic Information Systems: The Developer\u27s Perspective

Geographic information systems, which manage data describing the surface of the earth, are becoming increasingly popular. This research details the current state of the art of geographic data processing in terms of the needs of the geographic information system developer. The research focuses chiefly on the geographic data model--the basic building block of the geographic information system. The two most popular models, tessellation and vector, are studied in detail, as well as a number of hybrid data models. In addition, geographic database management is discussed in terms of geographic data access and query processing. Finally, a pragmatic discussion of geographic information system design is presented covering such topics as distributed database considerations and artificial intelligence considerations

Digital halftoning and the physical reconstruction function

Originally presented as author's thesis (Ph. D.--Massachusetts Institute of Technology), 1986.Bibliography: p. 397-405."This work has been supported by the Digital Equipement Corporation."by Robert A. Ulichney

Simulating Urban Growth with Raster and Vector models: A case study for the city of Can Tho, Vietnam

Urban growth has been widely studied and many models (in particular Cellular Automata and Agent-Based Models) have been developed. Most of these models rely on two representations of the geographic space: raster and vector. Both representations have their own strengths and drawbacks. The raster models are simpler to implement and require less data, which explains their success and why most of urban growth models are based on this representation. However, they are not adapted to microscopic dynamics such as, for example, the construction of buildings. To reach such goal, a vector-based representation of space is mandatory. However, very few vector models exist, and none of them is easily adaptable to different case studies. In this paper, we propose to use a simple raster model and to adapt it to a vector representation of the geographic space and processes allowing studying urban growth at fine scale. Both models have been validated by a case study concerning the city of Can Tho, Vietnam

Interactive constraint-based space layout planning

Layout planning is the primordial design activity that determines the characteristics and performance of a building throughout its lifecycle. Due to its iterative nature, there is a growing interest in the automation of space layout planning to enhance the search for optimum design solutions. The approaches for automation range from constraint/heuristics-based to the application of numerical optimisation algorithms. Among these, the use of design constraints to guide the search of the solution space is well regarded due to its ability to model design problems of an applied nature with multiple objectives. Constraint-based approaches also allow interactivity between the designer and layout planning process, which simulates the iterative nature of creative design and can be integrated well with the existing design process. Interactivity also enhances the management of design knowledge through improved processing and visualisation of information. This paper presents a theoretical framework for interactive constraint-based layout optimisation with an implemented prototype for a hospital patient room interior layout. The theoretical framework was developed by analysing existing layout automation methods and interactive approaches through a review of relevant literature. Object-oriented computer programming was used to develop the prototype to demonstrate the proposed approach of interactive layout planning system. The framework augments the iterative design process by facilitating the active participation and sharing of the designer’s knowledge during the aggregation. With regard to the implementation of the framework in large problems, fast evaluation of design solution was found to be necessary to interact with the system in real time. Interactive constraint-based layout optimisation has, therefore, the ability to enhance the search process of optimum design solutions by augmenting the iterative nature of the creative design process