Object-Oriented Geographic Information System Data Model for Transit Trip-Planning Systems

2002 ◽  
Vol 1804 (1) ◽  
pp. 205-211 ◽  
Author(s):  
Ruihong Huang ◽  
Zhong-Ren Peng

Efficiency is essential to Internet transit trip-planning systems. High-quality data models of transit networks hold the key to efficiency of data querying and network analysis. Because of the schedule control and dynamic nature of the transit network, highway-based generic network models cannot be directly implemented by transit systems. In the process of developing an Internet transit trip-planning system, an object-oriented geographic information system data model, which handles the dynamic nature of transit systems, was developed. In this data model, the entire transit network and its components are modeled as space–time entities (objects) that have start times, end times, and spans of lifetime. A time map object controls the creation and destruction of these objects. Therefore, in the process of network search, only active components of the system (i.e., with transit services available) are built into the network topology. This has greatly reduced data redundancy and enhanced network search efficiency. The data model showed good performance when it was implemented in an online trip-planning service for Waukesha Metro Transit, Wisconsin.

Author(s):  
Harrison Togia ◽  
Oceana P. Francis ◽  
Karl Kim ◽  
Guohui Zhang

Hazards to roadways and travelers can be drastically different because hazards are largely dependent on the regional environment and climate. This paper describes the development of a qualitative method for assessing infrastructure importance and hazard exposure for rural highway segments in Hawai‘i under different conditions. Multiple indicators of roadway importance are considered, including traffic volume, population served, accessibility, connectivity, reliability, land use, and roadway connection to critical infrastructures, such as hospitals and police stations. The method of evaluating roadway hazards and importance can be tailored to fit different regional hazard scenarios. It assimilates data from diverse sources to estimate risks of disruption. A case study for Highway HI83 in Hawai‘i, which is exposed to multiple hazards, is conducted. Weakening of the road by coastal erosion, inundation from sea level rise, and rockfall hazards require adaptation solutions. By analyzing the risk of disruption to highway segments, adaptation approaches can be prioritized. Using readily available geographic information system data sets for the exposure and impacts of potential hazards, this method could be adapted not only for emergency management but also for planning, design, and engineering of resilient highways.


1989 ◽  
Vol 7 (1) ◽  
pp. 3-35
Author(s):  
Mojtaba Mozaffari ◽  
Yuzuru Tanaka
Keyword(s):  

2012 ◽  
Vol 246-247 ◽  
pp. 744-748
Author(s):  
Yue Lin Sun ◽  
Lei Bao ◽  
Yi Hang Peng

An effective analysis of the battlefield situation and spatio-temporal data model in a sea battlefield has great significance for the commander to perceive the battlefield situation and to make the right decisions. Based on the existing spatio-temporal data model, the present paper gives a comprehensive analysis of the characteristics of sea battlefield data, and chooses the object-oriented spatio-temporal data model to modify it; at the same time this paper introduces sea battlefield space-time algebra system to define various data types formally, which lays the foundation for the establishment of the sea battlefield spatio-temporal data model.


2012 ◽  
Vol 204-208 ◽  
pp. 4872-4877
Author(s):  
Da Xi Ma ◽  
Xiao Hong Liu ◽  
Li Wei Ma

By analyzing the attributes of three-dimensional space data model, the integrated 3D spatial data adopts object-oriented method for digital landslide modeling. It achieves spatial data modeling for landslide geological entity. An experimental case is given to indicate the feasibility of this approach for spatial data modeling.


Author(s):  
Ranko Vujosevic ◽  
Andrew Kusiak

Abstract The data base requirements for concurrent design systems are discussed. An object-oriented data base, which allows for definition of complex objects, specification of relationships between objects, and modular expandability without affecting the existing information is defined. The data base is developed based on the object-oriented data model implemented in Smalltalk-80. An assumption-based truth maintenance system for maintaining the dependency relationships between design and manufacturing information is described.


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