The Experts below are selected from a list of 624750 Experts worldwide ranked by ideXlab platform
Mei Po Kwan - One of the best experts on this subject based on the ideXlab platform.
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The Uncertain Geographic Context Problem in the Analysis of the Relationships between Obesity and the Built Environment in Guangzhou.
International Journal of Environmental Research and Public Health, 2018Co-Authors: Pengxiang Zhao, Mei Po Kwan, Suhong ZhouAbstract:Traditionally, static units of analysis such as administrative units are used when studying obesity. However, using these fixed Contextual units ignores environmental influences experienced by individuals in areas beyond their residential neighborhood and may render the results unreliable. This Problem has been articulated as the uncertain geographic Context Problem (UGCoP). This study investigates the UGCoP through exploring the relationships between the built environment and obesity based on individuals’ activity space. First, a survey was conducted to collect individuals’ daily activity and weight information in Guangzhou in January 2016. Then, the data were used to calculate and compare the values of several built environment variables based on seven activity space delineations, including home buffers, workplace buffers (WPB), fitness place buffers (FPB), the standard deviational ellipse at two standard deviations (SDE2), the weighted standard deviational ellipse at two standard deviations (WSDE2), the minimum convex polygon (MCP), and road network buffers (RNB). Lastly, we conducted comparative analysis and regression analysis based on different activity space measures. The results indicate that significant differences exist between variables obtained with different activity space delineations. Further, regression analyses show that the activity space delineations used in the analysis have a significant influence on the results concerning the relationships between the built environment and obesity. The study sheds light on the UGCoP in analyzing the relationships between obesity and the built environment.
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Contextual Uncertainties, Human Mobility, and Perceived Food Environment: The Uncertain Geographic Context Problem in Food Access Research.
American Journal of Public Health, 2015Co-Authors: Xiang Chen, Mei Po KwanAbstract:We examined the uncertainty of the Contextual influences on food access through an analytic framework of the uncertain geographic Context Problem (UGCoP).We first examined the compounding effects of two kinds of spatiotemporal uncertainties on people’s everyday efforts to procure food and then outlined three key dimensions (food access in real time, temporality of the food environment, and perceived nutrition environment) in which research on food access must improve to better represent the contributing environmental influences that operate at the individual level.Guidelines to address the UGCoP in future food access research are provided to account for the multidimensional influences of the food environment on dietary behaviors.
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ContextualUncertainties,HumanMobility,andPerceived FoodEnvironment:TheUncertainGeographicContext ProbleminFoodAccessResearch
2015Co-Authors: Xiang Chen, Mei Po KwanAbstract:We examined the uncertainty of the Contextual influencesonfoodaccessthrough an analytic framework of the uncertain geographic Context Problem (UGCoP). We first examined the compounding effects of two kinds of spatiotemporal uncertainties on people’s everyday efforts to procure food and then outlined three key dimensions (food access in real time, temporality of the food environment, and perceived nutrition environment) in which research on food access must improve to better represent the contributing environmental influences that operate at the individual level. Guidelines to address the UGCoP in future food access research are provided to account for the multidimensional influences of the food environmentondietarybehaviors.(Am
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How GIS can help address the uncertain geographic Context Problem in social science research
Annals of GIS, 2012Co-Authors: Mei Po KwanAbstract:The uncertain geographic Context Problem (UGCoP), first articulated by Kwan (2012; The uncertain geographic Context Problem. Annals of the Association of American Geographers, 102 (5), 958–968), refers to the Problem that findings about the effects of area-based Contextual variables on individual behaviors or outcomes may be affected by how Contextual units (e.g., neighborhoods) are geographically delineated and the extent to which these areal units deviate from the true geographic Context. It is a significant methodological Problem because it means that analytical results can differ for different delineations of Contextual units even if everything else is the same. Drawing upon Kwan (2012) and recent social science studies (especially environmental health and neighborhood effects research), this article further elaborates on the nature of the UGCoP and explores how recent advances in geographical information system (GIS) and geospatial technologies can help address the Problem. It discusses possible mean...
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The Uncertain Geographic Context Problem
Annals of the Association of American Geographers, 2012Co-Authors: Mei Po KwanAbstract:Any study that examines the effects of area-based attributes on individual behaviors or outcomes faces another fundamental methodological Problem besides the modifiable areal unit Problem (MAUP). It is the Problem that results about these effects can be affected by how Contextual units or neighborhoods are geographically delineated and the extent to which these areal units deviate from the true geographic Context. The Problem arises because of the spatial uncertainty in the actual areas that exert the Contextual influences under study and the temporal uncertainty in the timing and duration in which individuals experienced these Contextual influences. Using neighborhood effects and environmental health research as a point of departure, this article clarifies the nature and sources of this Problem, which is referred to as the uncertain geographic Context Problem (UGCoP). It highlights some of the inferential errors that the UGCoP might cause and discusses some means for mitigating the Problem. It reviews recent studies to show that both Contextual variables and research findings are sensitive to different delineations of Contextual units. The article argues that the UGCoP is a Problem as fundamental as the MAUP but is a different kind of Problem. Future research needs to pay explicit attention to its potential confounding effects on research results and to methods for mitigating the Problem. Key Words: Contextual uncertainty, environmental health, neighborhood effects, uncertain geographic Context Problem, UGCoP.
Michael Damm - One of the best experts on this subject based on the ideXlab platform.
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security and privacy of electric vehicles in the smart grid Context Problem and solution
Design and Analysis of Intelligent Vehicular Networks and Applications, 2013Co-Authors: Hasen Nicanfar, Seyedali Hosseininezhad, Peyman Talebifard, Victor C. M. Leung, Michael DammAbstract:The technology, security and privacy requirements of the electric vehicle (EV) in the smart grid (SG) Context, especially when the EV acts as mobile power storage, have gained much attention from the research community and market recently. This role of the EV is motivated by the increase in capacity of the power storages in the EV. In this paper, first we present different situations that an EV can be in the SG Context and their privacy issues. Then, we provide two authentication schemes, first one between the EV and a trusted SG server directly, and second one via a non-trusted third party entity with a robust privacy-preserving agenda. Our analysis shows that our mechanisms are secure and robust enough to make sure the privacy of the customers is fully preserved, and at the same time, are efficient since they consume very limited resources.
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DIVANet@MSWiM - Security and privacy of electric vehicles in the smart grid Context: Problem and solution
Proceedings of the third ACM international symposium on Design and analysis of intelligent vehicular networks and applications - DIVANet '13, 2013Co-Authors: Hasen Nicanfar, Seyedali Hosseininezhad, Peyman Talebifard, Victor C. M. Leung, Michael DammAbstract:The technology, security and privacy requirements of the electric vehicle (EV) in the smart grid (SG) Context, especially when the EV acts as mobile power storage, have gained much attention from the research community and market recently. This role of the EV is motivated by the increase in capacity of the power storages in the EV. In this paper, first we present different situations that an EV can be in the SG Context and their privacy issues. Then, we provide two authentication schemes, first one between the EV and a trusted SG server directly, and second one via a non-trusted third party entity with a robust privacy-preserving agenda. Our analysis shows that our mechanisms are secure and robust enough to make sure the privacy of the customers is fully preserved, and at the same time, are efficient since they consume very limited resources.
Brian Hodges - One of the best experts on this subject based on the ideXlab platform.
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student feedback in Problem based learning a survey of 103 final year students across five ontario medical schools
Medical Education, 2001Co-Authors: Amish Parikh, Kylen Mcreelis, Brian HodgesAbstract:Context Problem based learning (PBL) has become an integral component of medical curricula around the world. In Ontario, Canada, PBL has been implemented in all five Ontario medical schools for several years. Although proper and timely feedback is an essential component of medical education, the types of feedback that students receive in PBL have not been systematically investigated. Objectives In the first multischool study of PBL in Canada, we sought to determine the types of feedback (grades, written comments, group feedback from tutor, individual feedback from tutor, peer feedback, self-assessment, no feedback) that students receive as well as their satisfaction with these different feedback modalities. Subjects and methods We surveyed a sample of 103 final year medical students at the five Ontario schools (University of Toronto, McMaster University, Queens University, University of Ottawa and University of Western Ontario). Subjects were recruited via E-mail and were asked to fill out a questionnaire. Results Many students felt that the most helpful type of feedback in PBL was individual feedback from the tutor, and indeed, individual feedback was one of the more common types of feedback provided. However, although students also indicated a strong preference for peer and group feedback, these forms of feedback were not widely reported. There were significant differences between schools in the use of grades, written comments, self-assessment and peer feedback, as well as the immediacy of the feedback given. Conclusions Across Ontario, students do receive frequent feedback in PBL. However, significant differences exist in the types of feedback students receive, as well as the timing. Although rated highly by students at all schools, the use of peer feedback and self-assessment is limited at most, but not all, medical schools.
Arthur Stinner - One of the best experts on this subject based on the ideXlab platform.
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Quantifying Equestrian Show Jumping: A Large Context Problem for Physics Students
2013Co-Authors: Arthur StinnerAbstract:ASEJ, Volume 43, Number 1, June 2013 Equestrian show jumping has become a popular spectator sport in Canada since the Beijing Olympic Games in 2008. Canada received a gold medal in singles and a silver in team competition. Eric Lamaze and his stallion Hickstead, generally regarded as the best showjumping horse of his generation, became internationally famous, and Lamaze was ranked first in the world. Unfortunately, three years later Hickstead suddenly died in Verona, Italy, after jumping a clear round. This tragic event plunged the equestrian community into deep mourning. These events reawakened the love for horses I acquired when working in the forestry industry in British Columbia as a young man. As a physics educator, I naturally became interested in the physics of the jumping motion of these magnificent animals. I remember a letter written by an irate reader of the British journal New Scientist in response to my article “Physics and the Bionic Man” (Stinner 1980). The gentleman argued that my testing the feats claimed by the bionic man, using the laws of physics, spoiled the enjoyment of many devotees of the popular TV series The Six Million Dollar Man. As students of physics, we can always appreciate the aesthetics of phenomena such as rainbows and sunsets, but understanding the physics should enrich our aesthetic appreciation. Similarly, equestrian show jumping can be appreciated on more than one level.
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The Large Context Problem (LCP) Approach.
Interchange, 2006Co-Authors: Arthur StinnerAbstract:This article traces the development of a Contextual approach to the teaching of science (physics) subsequently called the Large Context Problem (LCP) approach. This approach is based on the general observation that learning could be well motivated by a Context with one unifying central idea capable of capturing the imagination of the students.
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Philosophy, thought experiments and large Context Problems in the secondary school physics course
International Journal of Science Education, 1990Co-Authors: Arthur StinnerAbstract:In this paper it is argued that scientific thinking in physics involves the progressive clarification of the relationship between mathematics and physics, as well as the clarification of scientific induction and deduction. Furthermore, the framing of theories and the working out of their consequences involve the exercise of the imagination. One locus of scientific imagination is the thought experiment, primarily understood as a mental device that helps explicate concepts and principles, and unravel paradoxes. A sound curriculum in physics, however, must also be based on broad principles of education. These principles are first stated and then it is argued that in conjunction with what we have said about scientific thinking we should teach physics in terms of Contexts of inquiry. These Contexts relate to questions, method, Problems, experiments, history, and the large Context Problem itself. Here we find the clarification of induction and deduction, as well as the proper placing of the thought experiment. ...
Hasen Nicanfar - One of the best experts on this subject based on the ideXlab platform.
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security and privacy of electric vehicles in the smart grid Context Problem and solution
Design and Analysis of Intelligent Vehicular Networks and Applications, 2013Co-Authors: Hasen Nicanfar, Seyedali Hosseininezhad, Peyman Talebifard, Victor C. M. Leung, Michael DammAbstract:The technology, security and privacy requirements of the electric vehicle (EV) in the smart grid (SG) Context, especially when the EV acts as mobile power storage, have gained much attention from the research community and market recently. This role of the EV is motivated by the increase in capacity of the power storages in the EV. In this paper, first we present different situations that an EV can be in the SG Context and their privacy issues. Then, we provide two authentication schemes, first one between the EV and a trusted SG server directly, and second one via a non-trusted third party entity with a robust privacy-preserving agenda. Our analysis shows that our mechanisms are secure and robust enough to make sure the privacy of the customers is fully preserved, and at the same time, are efficient since they consume very limited resources.
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DIVANet@MSWiM - Security and privacy of electric vehicles in the smart grid Context: Problem and solution
Proceedings of the third ACM international symposium on Design and analysis of intelligent vehicular networks and applications - DIVANet '13, 2013Co-Authors: Hasen Nicanfar, Seyedali Hosseininezhad, Peyman Talebifard, Victor C. M. Leung, Michael DammAbstract:The technology, security and privacy requirements of the electric vehicle (EV) in the smart grid (SG) Context, especially when the EV acts as mobile power storage, have gained much attention from the research community and market recently. This role of the EV is motivated by the increase in capacity of the power storages in the EV. In this paper, first we present different situations that an EV can be in the SG Context and their privacy issues. Then, we provide two authentication schemes, first one between the EV and a trusted SG server directly, and second one via a non-trusted third party entity with a robust privacy-preserving agenda. Our analysis shows that our mechanisms are secure and robust enough to make sure the privacy of the customers is fully preserved, and at the same time, are efficient since they consume very limited resources.