Category Archives: my PUBLIC PRESENCE

Posts inspired by my own public appearances

Pålitelighet og sårbarhet – et ikke-tema i nyttekostnadsanalyser?

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Revised on: 2015-09-09

Pålitelighet og sårbarhet er to forhold av betydning for transportbrukere som i dag ikke tas hensyn til i vurdering av samferdselsprosjekter. Få vil være i tvil om at både avsender, mottaker, transportør og samfunnet generelt påføres til dels betydelige tilleggskostnader når varer eller personer ikke kommer frem dit de skal når de skal. At et pålitelig vegnett representerer en nytteverdi er derfor innlysende. Hvorfor er slike vurderinger ikke med når vegprosjekter blir vurdert?

Dette er den norske originalversjonen av Why reliability and vulnerability should be an issue in road development projects. Denne artikkelen stod på trykk i Samferdsel, nr. 3/2004 (pdf).

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Shortest Path Computation: A Comparative Analysis

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Revised on: 2011-07-22

Current research work into establishing a performance efficiency hierarchy between Java, C++ and ArcView is described and experimentation is performed in order to statistically compare shortest path query execution time, response time and implementation issues.

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A spatial framework for modeling hazards to transportation lifelines

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Revised on: 2011-07-22

Transportation networks are exposed to a wide range of  natural hazards and this study has developed a GIS tool for analyzing these hazards. The primary hazards included in this study are avalanches, landslides, flooding, earthquakes, wildfires, and rockfall. Although the primary focus of this research is roads, it is equally applicable to other transportation lifelines, such as railways, canals/waterways, or transmission lines for power, gas or oil. This presentation provides an overview of the spatial framework, current results and limitations, and directions for further research. MFworks was used as a GIS tool, along with a self-developed Java application.

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How to make a straight line square

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Revised on: 2011-07-22

Euler’s famous “Königsberg bridge” question, dating back as far as 1736, is often seen as the starting point of modern path finding – was it possible to find a path through the city of Königsberg crossing each of its seven bridges once and only once and then returning to the origin? Euler’s methods formed the basis of what is known as graph theory, and which in turn paved the way for path finding algorithms. Traditionally, network analysis, path finding and route planning have been the domain of graph theory and vector GIS, which is where most algorithms find their application. Contrary to such common wisdom, the research of this thesis for the Msc in GIS explores the topic of network analysis in raster GIS, using MFworks as example software. Current algorithms, procedures and network modelling techniques are investigated and common artefacts are explained.

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