City and Regional Planning / Şehir ve Bölge Planlama

Permanent URI for this collectionhttps://hdl.handle.net/11147/4274

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  • Article
    Citation - WoS: 9
    Citation - Scopus: 10
    Modelling Trip Distribution With Fuzzy and Genetic Fuzzy Systems
    (Taylor and Francis Ltd., 2013) Kompil, Mert; Çelik, Hüseyin Murat; Çelik, Hüseyin Murat; 02.03. Department of City and Regional Planning; 02. Faculty of Architecture; 01. Izmir Institute of Technology
    This paper explores the potential capabilities of fuzzy and genetic fuzzy system approaches in urban trip distribution modelling with some new features. First, a simple fuzzy rule-based system (FRBS) and a novel genetic fuzzy rule-based system [GFRBS: a fuzzy system improved by a knowledge base learning process with genetic algorithms (GAs)] are designed to model intra-city passenger flows for Istanbul. Subsequently, their accuracy, applicability and generalizability characteristics are evaluated against the well-known gravity- and neural network (NN)-based trip distribution models. The overall results show that: traditional doubly constrained gravity models are still simple and efficient; NNs may not show expected performance when they are forced to satisfy trip constraints; simply-designed FRBSs, learning from observations and expertise, are both efficient and interpretable even if the data are large and noisy; and use of GAs in fuzzy rule-based learning considerably increases modelling performance, although it brings additional computation cost.
  • Article
    Citation - WoS: 25
    Citation - Scopus: 34
    Sample Size Needed for Calibrating Trip Distribution and Behavior of the Gravity Model
    (Elsevier Ltd., 2010) Çelik, Hüseyin Murat; Çelik, Hüseyin Murat; 02.03. Department of City and Regional Planning; 02. Faculty of Architecture; 01. Izmir Institute of Technology
    Conventional calibration algorithms of trip distribution models assume that the analyst has a whole base year trip matrix. To attain a whole trip matrix, the sample size for travel surveys needed to be as large as possible. However, this could be very expensive especially in large cities. Some studies in the past showed a small sized sample would be enough to estimate functional parameters of observed trip length frequency distribution. But the performance of a gravity model with small sized samples has never been addressed. This empirical study has shown that sample sizes as small as 1000 (even smaller for quick response studies) could be as dependable as large sample surveys using a line search calibration algorithm. © 2009 Elsevier Ltd. All rights reserved.