120 research outputs found

    A Time-Space Analysis of Urban Activities with Focus on the Relationship between ICT and Activity-Travel

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    Information and communications technology (ICT) has evolved substantially and impacted urban residents’ everyday life quite substantially in the past decade. The rapid spread of mobile telecommunications technologies has produced significant changes in relationships among communications, marketing and distribution, and transportation. As mobile technologies diminish time-space constraints that have governed telecommunication, they are prompting the emergence of new life styles with unprecedented ways in which urban space is consumed. The focus of this study is on how mobile telecommunication technologies have influenced daily activity and travel behaviors of urban residents. Temporal and spatial characteristics of their activity-travel patterns are empirically analyzed using activity diary data sets collected by the authors in the Kofu area of Japan. The survey is designed with the intent of capturing both patterns of movements in the urban area and patterns of activities that induced the movements. Questions regarding telecommunications activities are introduced into the activity-travel diary that had been developed by the authors to facilitate the acquisition of information on the occurrence and contents of telecommunications activities. The analytical framework of this study is formed by integrating urban residents’ time-space paths and virtual links representing telecommunications activities. Time-space paths are formed in a physical urban space while satisfying temporal and spatial constraints imposed by HĂ€gerstrand’s prism. Conventional means of inter-individual communication (meeting, stationary telephones, mailed letters and telegrams) are all subject to certain constraints in the time-space domain. On the other hand, telecommunications activities by mobile technologies are not subjected to many of the constraints and can influence travel decisions more spontaneously than do conventional means of communication. Several hypotheses concerning ICT and activity patterns are postulated and empirically examined with the results of the diary surveys. Examples of the hypotheses are as follows. As the use of mobile telecommunications technologies increases, 1) the activity frequency tends to increase, 2) the spatial distribution of activities tends to spread out, that is, the action space tends to expand spatially, and 3) patterns of trip chaining tend to change themselves, with more stops incorporated into a home-based trip chain (i.e., a sequence of trips starting from and ending at home, through which a set of activity locations are visited). It is also hypothesized that 4) the way mobile technologies influence the individual’s activity-travel patterns varies by his personal characteristics, especially life cycle stage and life style. The Survey of Communication, Activity and Travel, denoted by “SCAT,” was conducted twice to form the database of this study. The first survey involved about 150 university students and data on weekly activity patterns and mobile telecommunication incidents were collected. The second survey addressed about 150 households (322 individuals) and activity diaries on two consecutive days and mobile telecommunication information were obtained. The first SCAT data are used to examine basic properties of ICT–activity-travel relationships of “heavy mobile-informed travelers” because students are certainly standing on the forefront of ICT use. On the other hand, the second SCAT data are used to analyze characteristics of joint activity engagement by household members as a result of ICT use among household members. Then, using both of the SCAT data sets, the hypotheses are examined and statistical evidence is presented. Finally, implications of the findings are summarized and directions are suggested for future research on ICT, activity and travel.

    The Effect of Accessibility Improvement on Tourist Excursion Behaviors: Empirical Case Studies in Japan

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    One of the most important issues in a current situation in tourism in Japan is to identify how attractive cities or towns we can provide visiting tourists as a tourism product satisfying needs and wants. It is therefore necessary to grasp what kind of needs and wants potential tourists can obtain from their experience of visiting cities. For this purpose, an area marketing and management approach (AMMA) is expected to be effective one. In this paper a basic framework of our AMMA will be introduced. In addition, a practical procedure for quantitatively measuring the effect of accessibility improvement on tourist travel demand and activity patterns will be proposed. This paper discusses a practical method for measuring accessibility improvement effect focusing on the increase of the number of visitors to the tourism areas where the level of service in accessing transport facilities is planning to be improved. Two case studies in Japan will be presented in this paper

    Empirical Analysis Of Leisure Driver Decision Structures Underlying Sa/Pa Choice Behaviors On Expressways In Japan

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    Recently, it has been recognized that leisure drivers have a variety of needs when using expressways and that service and parking areas (SA/PAs) are required to offer not only traditional rest stop services but also additional services, such as refreshments, dining, and souvenir shopping. As previous research on driver decisions related to SA/PA choice behaviors is limited, it is necessary to identify the factors determining SA/PA choice behaviors to develop marketing strategies for promoting SA/PA use. Therefore, one of the objectives of this research is to analyze leisure driver SA/PA choice behaviors and their level of customer satisfaction with SA/PA services. A paper-based questionnaire was administered to the drivers who stopped at the studied SA/PAs on the survey day; a web-based survey is planned as a complementary survey. Structural equation modeling was applied to represent the decision structure underlying SA/PA choice behavior. We also discuss marketing strategies to promote SA/PA use for leisure drivers. In addition, a SA/PA choice model was developed to identify whether a given driver would stop at any of the studied SA/PAs or not and to identify which SA/PA would be chosen

    A Time-Space Analysis of Urban Activities with Focus on the Relationship between ICT and Activity-Travel

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    Information and communications technology (ICT) has evolved substantially and impacted urban residents' everyday life quite substantially in the past decade. The rapid spread of mobile telecommunications technologies has produced significant changes in relationships among communications, marketing and distribution, and transportation. As mobile technologies diminish time-space constraints that have governed telecommunication, they are prompting the emergence of new life styles with unprecedented ways in which urban space is consumed. The focus of this study is on how mobile telecommunication technologies have influenced daily activity and travel behaviors of urban residents. Temporal and spatial characteristics of their activity-travel patterns are empirically analyzed using activity diary data sets collected by the authors in the Kofu area of Japan. The survey is designed with the intent of capturing both patterns of movements in the urban area and patterns of activities that induced the movements. Questions regarding telecommunications activities are introduced into the activity-travel diary that had been developed by the authors to facilitate the acquisition of information on the occurrence and contents of telecommunications activities. The analytical framework of this study is formed by integrating urban residents' time-space paths and virtual links representing telecommunications activities. Time-space paths are formed in a physical urban space while satisfying temporal and spatial constraints imposed by HĂ€gerstrand's prism. Conventional means of inter-individual communication (meeting, stationary telephones, mailed letters and telegrams) are all subject to certain constraints in the time-space domain. On the other hand, telecommunications activities by mobile technologies are not subjected to many of the constraints and can influence travel decisions more spontaneously than do conventional means of communication. Several hypotheses concerning ICT and activity patterns are postulated and empirically examined with the results of the diary surveys. Examples of the hypotheses are as follows. As the use of mobile telecommunications technologies increases, 1) the activity frequency tends to increase, 2) the spatial distribution of activities tends to spread out, that is, the action space tends to expand spatially, and 3) patterns of trip chaining tend to change themselves, with more stops incorporated into a home-based trip chain (i.e., a sequence of trips starting from and ending at home, through which a set of activity locations are visited). It is also hypothesized that 4) the way mobile technologies influence the individual's activity-travel patterns varies by his personal characteristics, especially life cycle stage and life style. The Survey of Communication, Activity and Travel, denoted by "SCAT,” was conducted twice to form the database of this study. The first survey involved about 150 university students and data on weekly activity patterns and mobile telecommunication incidents were collected. The second survey addressed about 150 households (322 individuals) and activity diaries on two consecutive days and mobile telecommunication information were obtained. The first SCAT data are used to examine basic properties of ICT–activity-travel relationships of "heavy mobile-informed travelers” because students are certainly standing on the forefront of ICT use. On the other hand, the second SCAT data are used to analyze characteristics of joint activity engagement by household members as a result of ICT use among household members. Then, using both of the SCAT data sets, the hypotheses are examined and statistical evidence is presented. Finally, implications of the findings are summarized and directions are suggested for future research on ICT, activity and travel

    An Empirical Model of Expressway Drivers Behaviors on Stopover at sa/pa involving the Location Choice

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    Drivers on expressway have not only need of high speed and safety but also other various kinds of services for their comfortable traveling. The Japan expressway company (called NEXCO) privatized in 2005 has increasingly attached great importance to improvement of those services. Service and parking areas (SA/PAs) are consequently required to offer not only traditional rest stop services but also additional services, such as refreshments, dining, and souvenir shopping. Previous researches of driver decision-making on stopover at SA/PA and on which SA/PA is chosen have been hardly advanced because of lack of survey data. These data are clearly useful to identify the factors determining SA/PA choice behaviors and also to develop marketing strategies for promoting SA/PA use. This research aims to analyze driverfs decision structures on SA/PA choice behaviors and the level of customer satisfaction with SA/PA services. The web-based questionnaire surveys were conducted twice to the drivers who stopped at the studied SA/PAs on the surveyed period. One was done at the section on Chugoku expressway in 2012 and the other was on Sanyo expressway in 2013. Based on the results from our previous study, in which a structural equation model (SEM) was applied to represent the decision structure underlying SA/PA choice behavior using Chugoku expressway data in 2012, a discrete choice behavior model is developed to identify whether a given driver would stop at any of the studied SA/PAs or not and to identify which SA/PA would be chosen. In this modeling, two different types of the nested logit models, in which the upper level is the decision on stopover at SA/PA or not and the lower level is the one on choice of the location, are mainly calibrated using both the data set of Chugoku in 2012 and those of Sanyo in 2013. The goodness of fit of estimated models including statistical significance of estimated parameters are discussed to clarify the differences in determining factors between Chugoku and Sanyo expressways. The results indicate that both two types of nested logit models are significant in common while the goodness of fit for Chugoku models are different from that for Sanyo models. They also indicate that those differences are caused by driverfs characteristics such as travel distance and frequency of expressway use, and by SA/PA characteristics such as the contents of services and the CS (customer satisfaction rate) and the location distribution

    Cholesterol uptake of isolated rat hepatocytes is accelerated by several kinds of phosphatidylcholine

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    AbstractUptake of cholesterol by isolated rat hepatocytes in a serum-free medium was remarkably enchanced by dispersion with several kinds of phosphatidylcholine. Of the various phosphatidylcholines tested, dilinoylphosphatidylcholine had the strongest accelerating effect, while dipalmitoylphosphatidylcholine was the weakest. The abilities to accelerate cholesterol uptake were in proportion to the content of unsaturated fatty acid in the phosphatidylcholine used. It was confirmed by electron microscopy that there is no relation between the size of the cholesterol-phosphatidylcholine complex and uptake. These data suggest that recognition of unsaturated fatty acids in phosphatidylcholine by isolated cells enhances uptake of cholesterol.Cholesterol uptake(Isolated rat hepatocyte)PhosphatidylcholineUnsaturated fatty acidDioleoylphosphatidylcholineDipalmitoylphosphatidylcholin

    Fractional anisotropy in the centrum semiovale as a quantitative indicator of cerebral white matter damage in the subacute phase in patients with carbon monoxide poisoning: correlation with the concentration of myelin basic protein in cerebrospinal fluid

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    Carbon monoxide (CO) poisoning leads to demyelination of cerebral white matter (CWM) fibers, causing chronic neuropsychiatric symptoms. To clarify whether fractional anisotropy (FA) from diffusion tensor imaging in the centrum semiovale can depict demyelination in the CWM during the subacute phase after CO inhalation, we examined correlations between FA in the centrum semiovale and myelin basic protein (MBP) in cerebrospinal fluid. Subjects comprised 26 adult CO-poisoned patients ≀60 years old. MBP concentration was examined for all patients at 2 weeks after CO inhalation. The mean FA of the centrum semiovale bilaterally at 2 weeks was also examined for all patients and 21 age-matched healthy volunteers as controls. After these examinations, the presence of chronic symptoms was checked at 6 weeks after CO poisoning. Seven patients displayed chronic symptoms, of whom six showed abnormal MBP concentrations. The remaining 19 patients presented no chronic symptoms and no abnormal MBP concentrations, with MBP concentrations undetectable in 16 patients. The MBP concentration differed significantly between patients with and without chronic symptoms. The mean FA was significantly lower in patients displaying chronic symptoms than in either patients without chronic symptoms or controls. After excluding the 16 patients with undetectable MBP concentrations, a significant correlation was identified between MBP concentration and FA in ten patients. The present results suggest that FA in the centrum semiovale offers a quantitative indicator of the extent of demyelination in damaged CWM during the subacute phase in CO-poisoned patients
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