Time and Date  

: 

1 October 2007, 10.00 am - 12.00 noon 

Venue  

: 

Conference Room, Department of Architecture, SDE1 Level 3, School of Design and Environment, NUS   

Student's Name 

: 

Simon Yanuar Putra 

Title of Thesis   

: 

A Perceptual Evaluation of Urban Space using GIS-based 3D Volumetric Visibility Analysis    

Abstract 

: 

Traditional GIS (Geographic Information System)-based visibility analysis has been conducted mainly two-dimensionally based on the concept isovist in architectural and urban space or the concept viewshed in terrain and landscape analysis. Recent developments of non-GIS spherical analysis such as SOI, SVF, and Sky Opening, have inspired development of a GIS-based volumetric visibility analysis referred as the Viewsphere. It was proposed in this dissertation for measuring the quality of urban open space, by volumetric computation of ambient optic array, a concept originated from Gibson’s ecological perception theory. As its predecessors the isovist and the viewshed analysis, the concept of viewsphere identifies visible and invisible parts of geometrical surfaces from vantage points. Through its development, we can operate volumetric computation of visible urban space.

Test cases were conducted in Singapore’s urban spaces, and Viewsphere analysed the existing and proposed urban form in these cases with rapid geometric modelling and visibility computation, and results were evaluated for understanding the potential impact of open space quality induced by urban geometry. The visual volumes of pedestrian viewers along urban streets and public spaces are monitored and measured by urban space indicators quantitatively. The results are then compared with the traditional isovist-based visual analysis. Surveys of pedestrians’ spatial and temporal perceptions were conducted at above locations, and the results were then compared statistically with new volumetric urban space indicators.

Statistical relationships were established by correlation and regression analyses, and significant quadratic relationships were discovered between human perceptions and volumetric measurement of visible space. The regression analyses then established predictive models to evaluate pedestrian spatial perceptions of any given 3D model of urban spaces. With the consideration of the third dimension of urban space, we argue that that a volumetric visibility impact assessment for large-scale urban design and development will provide a more relevant result than planar measurement and will provide better information about how urban quality can be achieved by the alternative urban forms and interventions.

Keywords: urban space, 3D GIS, spatial perceptions, visibility analysis

Under the recently established open-exam system, academic staff as well as research students are welcome to attend the Ph.D. oral defence. 

We would appreciate if you would register your attendance with Rozita via email by 27 September 2007. The exam panel members and supervisors need not register (seats will be reserved for them).

The candidate will give a 45-minute presentation, followed by a time of Q&A and subsequently, where necessary, a closed-door session involving only the exam panel will take place. For the open session, please note the following guidelines. 

1. The exam panel members can ask specific questions on the thesis as well as general questions to test the fundamentals and knowledge relevant to the subject.

2. The candidate's supervisor(s) can be present as observer(s) without Q&A right. 

3. All other participants can ask questions pertaining to the candidate's presentation during the Q&A session. 

4. Besides time control and moderating the exam process, the Chair of the exam panel has the right to intervene or overrule if, in his/her judgment, a question raised is inappropriate, irrelevant or inconsequential to the examination.

We look forward to your participation.