Perception Aspects in Underground Spaces using ... - TOI - TU Delft

spaces. There are also other aspects that play a role in perception, but in this work the decisionwas made to focus only on these two, and to show a way to deal with qualitative data in general.This work addresses the perception of public safety and comfort in underground stations,considering various determinants of these aspects. A conceptual model served as a mainframework for this research. The research results of Steffen (1979, 1982), Passini (1984, 1992),Van Wegen and Van der Voordt (1991); Carmody and Sterling (1993), Korz (1998) wereimportant input for the design of a conceptual model. In addition, the interviews were carried outwith the architects who already had an experience in designing underground stations. Theseinterviews were an important input for the conceptual model as well. Each of the architectsinterviewed 1 had their own approach and opinion regarding aspects related to user perception.Those interviews confirmed earlier statement given by Hamel (1990), that the architect reliedmainly on their intuition when it came to solving the issues related to user associated aspects.The conceptual model served as a basis for the questionnaire design. This questionnaire was usedas a method to obtain information from the users regarding different underground stations in theNetherlands. In such way, data was gathered on perception of different environments. This dataformed a base for modeling. A general name for studying information acquisition, recording,organization, retrieval, display and dissemination is referred to as information processing.Knowledge is theoretical and involves practical understanding of a subject. Therefore, knowledgemodeling can be defined as organizing information in some logical relationships (Slamecka,1994). The data used for information processing is 'soft' data, representing different views ofusers regarding different underground space environments. Therefore, there is a need for aspecific type of information processing and knowledge modeling that would enable the modelingof soft data. Traditional techniques, such as statistical methods, have been used until now forsuch type of research. However, there are various drawbacks to this method (Taylor, 2000). Inaddition, the classical computing theories and models are often found incapable of dealing withsuch uncertain and imprecise information. This implies that there is a need for special techniquesnot only to numerically represent such qualities but more importantly to treat the data inresponsible and the most suitable way. These techniques are known as soft computing techniques(Zadeh, 1994a; 1994b; Rojas, 1996) which are part of Artificial Intelligence.The main characteristic of soft computing techniques is their ability to deal with imprecise andill-defined data. The components of soft computing are considered to include fuzzy logic,artificial neural networks and genetic algorithms, evidence theory, probabilistic reasoning andmany others that could 'tolerate' uncertain and imprecise information (Chen, Ying and Cai, 1999).For this particular research, in respect to information processing and knowledge modeling, twoparticular techniques are of interest. These are fuzzy logic and neural network theory. Fuzzy logicaims at dealing with uncertainty and imprecision of a particular kind - fuzziness in concepts, withwhich people usually think and reason in their decision-making and problem-solving process.With fuzzy logic, the imprecision of data can be dealt with in a similar way to how humans usesuch data. Artificial neural networks model to some extent the human brain, and simulates its1 Interviews were carried out with ir. Moshé Zwarts (February 1999), ir. L.I. Vákár (April 1999), ir. Theo Fikkers(December 1998) and lately ir. Harry Volker (who was consulted on various occasions). The first three architects hadan experience in designing underground spaces, which was of great value for this research. The architect, H. Volker,has been a practising architect for more than 30 years and his suggestions were an important contribution to thisresearch, as the member of the chair TO&I.- 5 -