1,720,997 research outputs found
A model of the dynamic process of time allocation to discretionary activities
No full textThis paper proposes an activity-based methodology for representing the allocation of time to discretionary
activities during their programming and scheduling, based on the premise that both phases are to be considered
contextually and two aspects of the same decision process. The aim of this work is to extend the treatment
of utility maximization associated with carrying out two activities to J activities, so as to be able to segregate
the time spent traveling from the total amount of time dedicated to out-of-home activities. The global structure
of the model takes the form of a nested Tobit, particularly suited for reproducing a sequence of coupled
choices. The first choice concerns dividing up overall discretionary time between activities inside and outside
the home, then the second choice, subordinate to the first, involves rebudgeting the time between in- and outof-
home activities and trips. Thus the proposed model enables us to analyze the effects that each explicative
variable exerts on trips segregated from activities outside the home and, last, during demand forecasting, the
direct consequences of allocating discretionary time to trips following changes to an individual’s time budget.
A database created from a large-scale time-use survey (ISTAT 1988–1991) has been used for calibrating the
model coefficients
An activity-based model of women’s activity-travel patterns
No full textThe daily schedule of women is dictated by various requirements, and consequently their activity–travel patterns are often more complex and heterogeneous than those of their male counterparts. The problems associated with women’s mobility have highlighted the need to treat males and females separately when travel behavior is represented, especially when transportation policy interventions are concerned. Because of the substantial differences between men’s and women’s activity and travel behavior, they may respond differently to policy changes. This paper describes an activity-based approach to women’s travel behavior analysis, where time is allocated to in-home and out-of-home nonwork activities. A mixed joint probit–Tobit model was developed for daily time allocation to a set of nonwork activities; it allows for two-stage choice: first a woman decides whether to engage in activities outside the home (discrete choice), then she chooses which nonwork activities to participate in and allocates the time for them (discrete–continuous choice). Data used for model estimation were from the Mobility and Equal Opportunities Survey conducted in Cagliari, Italy, in 2006 by Centro Interuniversitario Ricerche Economiche e Mobilità in collaboration with Cagliari Provincial Authority’s Department of Gender Equality. The survey results highlight the dual roles of women who have to divide their time between work and family and indicate how transportation system efficiency plays a pivotal role in women’s schedules and imposes constraints on their leisure time more than does any other individual or household characteristic
Activity Time Allocation Models: A Comparison Between Maximum-Likelihood And Bayesian Estimators
No full text
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Random Utility-Based Microeconomic Model for Discretionary Activity Time Allocation
No full textThis paper proposes a microeconomic model for activity time allocation analysis that recognizes the random nature of daily time allocation, while also focusing on activities as a direct source of individual utility. More specifically, different levels of satisfaction (or utility) are gained from activity participation depending on the amount of time allocated to and the type of goods utilized in daily activities. The proposed model represents individual utility as a function of activity participation, accounts for the budget constraint in activity time allocation, allows for the interindividual and interactivity variation of utility, and considers the entire sphere of discretionary activities (in-home as well as out-of-home activities and trips). The aim of this study is to show how including a budget constraint in random utility models avoids overestimating the times allocated to activities and trips estimated by earlier random utility-based models that consider only time constraints. In particular, estimates of in-home and out-of-home discretionary activity and trip times for a sample of Italian single individuals from the 2003 National Institute of Statistics (ISTAT) Time Use Survey are presented. Compared with the estimates obtained using the simply time-constrained model with no budget constraint, the empirical findings show the variable effects to be interpreted in the same way. A greater number of significant variables in the double-constrained model denote greater complexity of the phenomenon to be represented. Incorporating the budget constraint diminishes the effect of some variables on activity time allocation
Effects of Physical Activity on Propensity for Sustainable Trips
No full textRecent statistics about the low level of participation by individuals in physical activities as well as a generalized propensity to use private vehicles have broadened the scope of transport studies to the sphere of health and well-being. The current shift in travel demand modeling to the activity-based paradigm is central to investigating which population segment is more likely to opt for environmentally friendly and energy-efficient vehicles, alternative modes of transport, and a rational use of the motor car. A mixed, joint Tobit–probit model analyzes the effects of time allocation for daily activity on the propensity to sustainable trips. The model is applied to a sample of workers and students age 14 and older, drawn from a time-use survey conducted in Turin, Italy, and its metropolitan area. The analysis suggests the presence of self-selection effects between active lifestyles and sustainable mandatory trips. The model predictions highlight the substantial contribution of transportation interventions in getting individuals to engage in healthier behaviors
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
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