This study analyzed the current characteristics of urban recreational parks and park users in Ban... more This study analyzed the current characteristics of urban recreational parks and park users in Bangkok. Six public parks in Bangkok were selected for data collection. Questionnaires were used in the data collection process. The result showed comparative efficiencies of the provision of public park in Bangkok in terms of park area ratio and population density. It was found that the most current public park users are 18-39 years old, middle to upper class income who have flexible working hours. The main access mode to parks is private automobile. Majority of public park users prefer to visit the park during weekends. Most of them visit the park 1-2 times a week and spend 1- 2 hours in the park. Exercise and relaxation are primary objectives of visiting the park while the most activities done at park are walking, jogging and aerobics. Aesthetics showed the highest score in satisfaction level of using park. Public park users in Bangkok showed high concern regarding the security at the pa...
Evacuation is one of the important preparedness measures in disaster management. It requires care... more Evacuation is one of the important preparedness measures in disaster management. It requires careful modeling and planning to minimize chaos and confusion during evacuation operations. The choice of decision-makers, whether to evacuate or stay in the area threatened by hazard, is an important aspect of evacuation travel behavior research. This is considered an essential input for evacuation modeling and planning. This study investigates the effects of various factors determining evacuation decision. A discrete choice model is proposed using the data collected through a face-to-face post-event survey from flood-affected households in Quezon City, Philippines. The model allows a choice among three alternatives of full, partial, and no evacuation. Results show that evacuation decision is determined by a combination of household characteristics and capacity-related factors (gender, educational level, presence of children, and number of years living in the residence, house ownership, number of house floor levels, type of house material), as well as hazard-related factors (distance from source of flood, level of flood damage, and source of warning). Findings in the study provide insights that can be considered by policy-makers in preparing for future evacuations. Appropriate programs can be designed to encourage full evacuation compliance of households that live nearest to the flood source and those living in houses with two or more floor levels who are more likely not to evacuate. Households with children can also be educated for full evacuation compliance since these households have higher probability to partially evacuate.
Mode choice methods model the traveler’s choice among a set of alternative mode of travels. This ... more Mode choice methods model the traveler’s choice among a set of alternative mode of travels. This study proposed the Fuzzy extension of the Analytic Network Process (FANP) to model the travel mode choice. Fuzzy set theory could be incorporated in the Analytic Network Process (ANP), which is a widely acceptable decision making tool in order to capture vagueness of the human decision. Triangular fuzzy numbers and their degree of fuzziness are used to express human judgment that is articulated in natural language. The method presented in this paper utilized the alpha cut and optimism index to transform the fuzzy comparative judgment matrix into sets of crisp matrices. The proposed method can be an alternative to conventional mode choice modeling techniques that are used to model travel mode choice problems.
This paper describes the issues and experiences in modeling travel mode choice using the Analytic... more This paper describes the issues and experiences in modeling travel mode choice using the Analytic Network Process (ANP). Some previous related literatures were reviewed. Basic formulation of the mode choice decision making problem using ANP was presented. Attributes such as comfort, travel time, travel cost, reliability, safety, etc. could be included in the ANP model. The methodology of ANP and its extensions were described. A case study was conducted to validate the applicability of the proposed ANP model. Advantages and disadvantages of using ANP in mode choice modeling were discussed. ANP requires more number of evaluations in the questionnaire process compared to AHP and other conventional mode choice methods. However, the process and results from ANP are transparent and easy to communicate with the public. It was concluded that it is possible to apply ANP to the mode choice problem especially when intangible/strategic factors should be included and when no historical data is a...
This paper investigates the modeling framework and the existing available data which could be use... more This paper investigates the modeling framework and the existing available data which could be used to develop the activity based travel demand model in Bangkok. The paper focuses on two main issues including “the population synthesizer” and “the activity generator”. It is found that there are possibilities to create the activity based model by using the existing available data from several sources. However, the modifications of the existing modeling framework from previous activity based modeling researches are needed in order to match the existing available data.
Ground water arsenic contamination is a well known health and environmental problem in Bangladesh... more Ground water arsenic contamination is a well known health and environmental problem in Bangladesh. Sources of this heavy metal are known to be geogenic, however, the processes of its release into groundwater are poorly understood phenomena. In quest of mitigation of the problem it is necessary to predict probable contamination before it causes any damage to human health. Hence our research has been carried out to find the factor relations of arsenic contamination and develop an arsenic contamination prediction model. Researchers have generally agreed that the elevated concentration of arsenic is affected by several factors such as soil reaction (pH), organic matter content, geology, iron content, etc. However, the variability of concentration within short lateral and vertical intervals, and the inter-relationships of variables among themselves, make the statistical analyses highly non-linear and difficult to converge with a meaningful relationship. Artificial Neural Networks (ANN) c...
ABSTRACT Groundwater arsenic contamination is a serious health and environmental problem in Bangl... more ABSTRACT Groundwater arsenic contamination is a serious health and environmental problem in Bangladesh. Sources or origin of this heavy metal is known to be natural but the process through which it is being released is poorly understood. In quest of mitigation of the problem it is important to predict area of probable contamination before it causes any damage to human health. In this research an attempt has been made to develop arsenic contamination risk map using a combination of classification tree and GIS technology. Six factors, which might have relation with arsenic contamination, namely geology, soil reaction (pH), elevation, soil organic matter, soil iron and proximity to river were selected as predictor variables. Prediction model was developed using classification algorithm of data mining technology in MATLAB using 80% training data. The developed classification trees were then validated using 20% test dataset. The best tree is found at pruning level 6 with cross validation accuracy result of 78.25%. The classification tree prediction model shows a complex relation of arsenic and the predictors. However, the root classifiers of the classification tree were found to be the surface elevation factor followed by geology. The best tree obtained from cross validation process was used to create the arsenic risk map in GIS environment. The developed risk map is found to be very close to reality where 87.9% of the data were found to be correctly predicted. The research shows that supported by geochemical process the surface elevation of an area determines the degree of accumulation of arsenic in the groundwater.
Various controlling factors such as lithology, slope angle, slope aspect, landuse, channel proxim... more Various controlling factors such as lithology, slope angle, slope aspect, landuse, channel proximity etc. are generally considered for the landslide hazard assessment. Although outer dependence of these parameters to a landslide is inevitably taken into account, inter-dependence ...
Proceedings of the 15th International Road …, Jan 1, 2005
ABSTRACT: In the country of Thailand, the alignment of intercity motorway is usually planned manu... more ABSTRACT: In the country of Thailand, the alignment of intercity motorway is usually planned manually by highway engineering experts. With the growing concerns in social and environmental impacts from road transport worldwide the planning based on engineering viewpoint only ...
This paper presents a method to facilitate the decision-making process in selecting sustainable f... more This paper presents a method to facilitate the decision-making process in selecting sustainable floors (elements) for buildings in Sri Lanka, taking into consideration environmental, economic and social assessments of materials used for these elements. Two types of elements are ...
This study analyzed the current characteristics of urban recreational parks and park users in Ban... more This study analyzed the current characteristics of urban recreational parks and park users in Bangkok. Six public parks in Bangkok were selected for data collection. Questionnaires were used in the data collection process. The result showed comparative efficiencies of the provision of public park in Bangkok in terms of park area ratio and population density. It was found that the most current public park users are 18-39 years old, middle to upper class income who have flexible working hours. The main access mode to parks is private automobile. Majority of public park users prefer to visit the park during weekends. Most of them visit the park 1-2 times a week and spend 1- 2 hours in the park. Exercise and relaxation are primary objectives of visiting the park while the most activities done at park are walking, jogging and aerobics. Aesthetics showed the highest score in satisfaction level of using park. Public park users in Bangkok showed high concern regarding the security at the pa...
Evacuation is one of the important preparedness measures in disaster management. It requires care... more Evacuation is one of the important preparedness measures in disaster management. It requires careful modeling and planning to minimize chaos and confusion during evacuation operations. The choice of decision-makers, whether to evacuate or stay in the area threatened by hazard, is an important aspect of evacuation travel behavior research. This is considered an essential input for evacuation modeling and planning. This study investigates the effects of various factors determining evacuation decision. A discrete choice model is proposed using the data collected through a face-to-face post-event survey from flood-affected households in Quezon City, Philippines. The model allows a choice among three alternatives of full, partial, and no evacuation. Results show that evacuation decision is determined by a combination of household characteristics and capacity-related factors (gender, educational level, presence of children, and number of years living in the residence, house ownership, number of house floor levels, type of house material), as well as hazard-related factors (distance from source of flood, level of flood damage, and source of warning). Findings in the study provide insights that can be considered by policy-makers in preparing for future evacuations. Appropriate programs can be designed to encourage full evacuation compliance of households that live nearest to the flood source and those living in houses with two or more floor levels who are more likely not to evacuate. Households with children can also be educated for full evacuation compliance since these households have higher probability to partially evacuate.
Mode choice methods model the traveler’s choice among a set of alternative mode of travels. This ... more Mode choice methods model the traveler’s choice among a set of alternative mode of travels. This study proposed the Fuzzy extension of the Analytic Network Process (FANP) to model the travel mode choice. Fuzzy set theory could be incorporated in the Analytic Network Process (ANP), which is a widely acceptable decision making tool in order to capture vagueness of the human decision. Triangular fuzzy numbers and their degree of fuzziness are used to express human judgment that is articulated in natural language. The method presented in this paper utilized the alpha cut and optimism index to transform the fuzzy comparative judgment matrix into sets of crisp matrices. The proposed method can be an alternative to conventional mode choice modeling techniques that are used to model travel mode choice problems.
This paper describes the issues and experiences in modeling travel mode choice using the Analytic... more This paper describes the issues and experiences in modeling travel mode choice using the Analytic Network Process (ANP). Some previous related literatures were reviewed. Basic formulation of the mode choice decision making problem using ANP was presented. Attributes such as comfort, travel time, travel cost, reliability, safety, etc. could be included in the ANP model. The methodology of ANP and its extensions were described. A case study was conducted to validate the applicability of the proposed ANP model. Advantages and disadvantages of using ANP in mode choice modeling were discussed. ANP requires more number of evaluations in the questionnaire process compared to AHP and other conventional mode choice methods. However, the process and results from ANP are transparent and easy to communicate with the public. It was concluded that it is possible to apply ANP to the mode choice problem especially when intangible/strategic factors should be included and when no historical data is a...
This paper investigates the modeling framework and the existing available data which could be use... more This paper investigates the modeling framework and the existing available data which could be used to develop the activity based travel demand model in Bangkok. The paper focuses on two main issues including “the population synthesizer” and “the activity generator”. It is found that there are possibilities to create the activity based model by using the existing available data from several sources. However, the modifications of the existing modeling framework from previous activity based modeling researches are needed in order to match the existing available data.
Ground water arsenic contamination is a well known health and environmental problem in Bangladesh... more Ground water arsenic contamination is a well known health and environmental problem in Bangladesh. Sources of this heavy metal are known to be geogenic, however, the processes of its release into groundwater are poorly understood phenomena. In quest of mitigation of the problem it is necessary to predict probable contamination before it causes any damage to human health. Hence our research has been carried out to find the factor relations of arsenic contamination and develop an arsenic contamination prediction model. Researchers have generally agreed that the elevated concentration of arsenic is affected by several factors such as soil reaction (pH), organic matter content, geology, iron content, etc. However, the variability of concentration within short lateral and vertical intervals, and the inter-relationships of variables among themselves, make the statistical analyses highly non-linear and difficult to converge with a meaningful relationship. Artificial Neural Networks (ANN) c...
ABSTRACT Groundwater arsenic contamination is a serious health and environmental problem in Bangl... more ABSTRACT Groundwater arsenic contamination is a serious health and environmental problem in Bangladesh. Sources or origin of this heavy metal is known to be natural but the process through which it is being released is poorly understood. In quest of mitigation of the problem it is important to predict area of probable contamination before it causes any damage to human health. In this research an attempt has been made to develop arsenic contamination risk map using a combination of classification tree and GIS technology. Six factors, which might have relation with arsenic contamination, namely geology, soil reaction (pH), elevation, soil organic matter, soil iron and proximity to river were selected as predictor variables. Prediction model was developed using classification algorithm of data mining technology in MATLAB using 80% training data. The developed classification trees were then validated using 20% test dataset. The best tree is found at pruning level 6 with cross validation accuracy result of 78.25%. The classification tree prediction model shows a complex relation of arsenic and the predictors. However, the root classifiers of the classification tree were found to be the surface elevation factor followed by geology. The best tree obtained from cross validation process was used to create the arsenic risk map in GIS environment. The developed risk map is found to be very close to reality where 87.9% of the data were found to be correctly predicted. The research shows that supported by geochemical process the surface elevation of an area determines the degree of accumulation of arsenic in the groundwater.
Various controlling factors such as lithology, slope angle, slope aspect, landuse, channel proxim... more Various controlling factors such as lithology, slope angle, slope aspect, landuse, channel proximity etc. are generally considered for the landslide hazard assessment. Although outer dependence of these parameters to a landslide is inevitably taken into account, inter-dependence ...
Proceedings of the 15th International Road …, Jan 1, 2005
ABSTRACT: In the country of Thailand, the alignment of intercity motorway is usually planned manu... more ABSTRACT: In the country of Thailand, the alignment of intercity motorway is usually planned manually by highway engineering experts. With the growing concerns in social and environmental impacts from road transport worldwide the planning based on engineering viewpoint only ...
This paper presents a method to facilitate the decision-making process in selecting sustainable f... more This paper presents a method to facilitate the decision-making process in selecting sustainable floors (elements) for buildings in Sri Lanka, taking into consideration environmental, economic and social assessments of materials used for these elements. Two types of elements are ...
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