Ken-etsu Uchida

Development of Transport Mode Choice Model by Using Adaptive Neuro-Fuzzy Inference System

Developing precise travel behavior models is important for estimating traffic demand and, consequently, for planning transportation systems. A study is presented that suggests a hybrid model that combines a stochastic model with a neuro-fuzzy inference system. The model is applied for estimating traveler behavior in the context of the problem of transport mode choice. Particularly, the multinomial logit model with neuro-fuzzy utility functions is developed to investigate shopping traveler preferences regarding the modes of bus, subway, and automobile. The model is evaluated by comparing its results with the results of a multinomial logit model. Moreover, the probabilities of selecting a transport mode obtained by applying the two models are compared with the actual transport mode choices, which show better performance of the proposed model. In addition, the model demonstrates good performance by estimating a large number of right choices during the validation process. A sensitivity analysis demonstrates the influence of time variations of mode subway on the probabilities of selecting a transport mode. The analysis highlights different behaviors of the models caused by the different utility functions. The results confirm that the proposed model can describe uncertainties regarding traveler decisions on the time of transport mode choice.

Travel Time Reliability Estimation Model Using Observed Link Flows in a Road Network

This article formulates a model that calculates travel time reliability in a road network. The sources of uncertainty addressed by the model are traffic capacity and travel demand. Because travel time reliability estimation problem, in general, is formulated as a path-based problem, path enumeration can be required in advance. Thus, the path travel time reliability can depend on a path set enumerated in advance. For the purpose of determining the unique travel time reliability, a model that estimates stochastic path flows by using observed link flows is then presented. This method does not require predefined path set. However, this method is similar to the standard maximum likelihood (ML) estimation method, the method presented in this study is easier to be solved because the number of unknown parameters is much smaller than that of the standard ML estimation method. Numerical experiments using two networks are carried out to demonstrate the model presented in this article.

A model evaluating effect of disaster warning issuance conditions on “cry wolf syndrome” in the case of a landslide

This study proposes a model that clarifies how disaster warning issuance conditions affect “cry wolf” syndrome. The disaster assumed in this study is landslide caused by heavy rainfall. Local authorities that issue disaster warnings are thought to tend to avoid the situation where casualty occurs without the issuance to residents of a disaster warning. As a result, the issuance conditions may be relaxed. Under this circumstance, however, the residents are thought to tend to ignore disaster warnings, since such warnings are inaccurate. Thus may emerge the “cry wolf” syndrome. In this study, a simulation model that expresses the behaviors of the local authority and the residents has been developed. For the purpose of demonstrating the model, numerical experiments were then carried out. In the numerical experiments, the effects of optimal issuance conditions for disaster warnings on the cost incurred by the resident were evaluated by using assumed parameters for the model.

Multi- Agent Simulation to Uncertain Civilian Return Trips during a Hypothetical Earthquake

After Hanshin-Awaji huge earthquake disaster in 1994, it has been important for Japanese local Government to build a comprehensive evacuation program of a large earthquake occurrence. In this program, it is substantial to give appropriate information on human behavior for the evacuation time. Thus, a new methodology based on behavior-oriented agent system should be developed. In this study, the production rules of the attributive groups were constructed in terms of the questionnaire survey for civilian return-trips from the working or the shopping places during earthquake disaster. Next, using the set of production rules composed of the questionnaire data, a multi-agent system model for return trips in a hypothetical large-scaled earthquake was built by a MAS method. It comes to the conclusion that the human behaviors during the earthquake impact were constructed by multi-agent system model and the possibility of the return-home was found in view of the conditions of the roads and the human attributes.

A Simplified Network Model for Travel Time Reliability Analysis in a Road Network

This paper proposes a simplified network model which analyzes travel time reliability in a road network. A risk-averse driver is assumed in the simplified model. The risk-averse driver chooses a path by taking into account both a path travel time variance and a mean path travel time. The uncertainty addressed in this model is that of traffic flows (i.e., stochastic demand flows). In the simplified network model, the path travel time variance is not calculated by considering all travel time covariance between two links in the network. The path travel time variance is calculated by considering all travel time covariance between two adjacent links in the network. Numerical experiments are carried out to illustrate the applicability and validity of the proposed model. The experiments introduce the path choice behavior of a risk-neutral driver and several types of risk-averse drivers. It is shown that the mean link flows calculated by introducing the risk-neutral driver differ as a whole from those calculated by introducing several types of risk-averse drivers. It is also shown that the mean link flows calculated by the simplified network model are almost the same as the flows calculated by using the exact path travel time variance.

A Study on Directional Navigation of Pedestrian down to the Underground

This study focuses on the sense of resistance on pedestrians down to the underground. In order to analyze a pedestrians direction navigation and way-finding behavior when pedestrians going down the stairs to the underground, the simulation experiment was conducted using personal computer by providing the visual information in movements. The results show that the directional navigation and way-finding behavior becomes difficult as the number of corners of the stairs increases. In addition, the visual information regarding direction might improve those behavior

A Study on Effects of ISO9000s in the Construction Sector

This study evaluat es the effects of introduction of both IS09000 series and construction management systems to construction sector and clarifies the preference rankings of requirements for quality management in terms of the questionnaire s survey on certification of IS09000 series and its background for three construction sectors. The surveys were carried out in 1996 and 2001. As a result, there are wide differences of the preference rankings of requirements for quality management between owners and acceptant. A latent stru cture of IS09000 series and its background were modeled based on an analysis of covariance structure. Consequently, it is clarified that extent of consulting on the construction management system affects the evaluation of acceptant for ISO9000 series.

An Analysis on Influence of Mobility Space Changes on Users in Urban Infrastructure Improvement

Tunnels change the spaces on the ground in which roads used to exist. They divide pedestrians and bicycle riders from car traffic and offer new kind of space to them. It has a great influence on the pedestrians and bicycle riders who used to care the car traffic. The purpose of this study is to estimate the influence on pedestrians and bicycle riders, not car drivers, focusing on two functions of the mobility space-transportation and stay. By the survey in the Hokkaido University Campus, the following was made clear. The new transportation function satisfies the pedestrians more than the cycle riders.