Kevin Stanley | Murdoch University (original) (raw)

Papers by Kevin Stanley

Scientific Reports

Energy expenditure can be used to examine the health of individuals and the impact of environment... more Energy expenditure can be used to examine the health of individuals and the impact of environmental factors on physical activity. One of the more common ways to quantify energy expenditure is to process accelerometer data into some unit of measurement for this expenditure, such as Actigraph activity counts, and bin those measures into physical activity levels. However, accepted thresholds can vary between demographics, and some units of energy measurements do not currently have agreed upon thresholds. We present an approach which computes unique thresholds for each individual, using piecewise exponential functions to model the characteristics of their overall physical activity patterns corresponding to well established sedentary, light, moderate and vigorous activity levels from the literature. Models are fit using existing piecewise fitting techniques and software. Most participants’ activity intensity profile is exceptionally well modeled as piecewise exponential decay. Using this...

2015 IEEE 40th Local Computer Networks Conference Workshops (LCN Workshops), 2015

Sensor devices and the emergent networks that they enable are capable of transmitting information... more Sensor devices and the emergent networks that they enable are capable of transmitting information between data sources and a permanent data sink. Since these devices have low-power and intermittent connectivity, latency of delivery for certain classes of data may be tolerated in an effort to save energy. Several previously developed algorithms employ models which considers the popularity of individual nodes within communities and forward messages to nodes with higher probability of delivery according to some heuristic. In previous work, we developed Community-Based-Forwarding (CBF) that considers the interactions between communities as a factor in message forwarding. Using this information, CBF is able to exploit intermediate connections between clusters to route messages with more balanced node participation and higher levels of reliability and efficiency. One disadvantage of CBF was an increased delivery latency for some subset of messages that could not be delivered using other algorithms. In this paper, we extend the semantics of CBF with the Hybrid CBF algorithm (HCBF) by optimizing forwarding inside communities by considering the social diversity (measured by Unique Interactions). We find that all performance metrics are improved with this heuristic on a representative set of human mobility traces, but most significantly the message delivery latency is substantially improved over the other algorithms studied.

International Journal of Environmental Research and Public Health, 2021

There is little understanding of how the built environment shapes activity behaviours in children... more There is little understanding of how the built environment shapes activity behaviours in children over different seasons. This study sought to establish how seasonal weather patterns, in a given year in a mid-western Canadian city, affect sedentary time (SED) in youth and how the relationship between season and SED are moderated by the built environment in their home neighbourhood. Families with children aged 9–14 years were recruited from the prairie city of Saskatoon, Canada. Location-specific, device-based SED was captured in children during three timeframes over a one-year period using GPS-paired accelerometers. Multilevel models are presented. Children accumulated significantly greater levels of SED in spring but significantly less SED in the fall months in comparison to the winter months. Children living in neighbourhoods with the highest density of destinations accumulated significantly less SED while in their home area in comparison to their counterparts, and this effect was...

ACM Transactions on Spatial Algorithms and Systems, 2020

Understanding how humans use and consume space by comparing stratified groups, either through obs... more Understanding how humans use and consume space by comparing stratified groups, either through observation or controlled study, is key to designing better spaces, cities, and policies. GPS data traces provide detailed movement patterns of individuals but can be difficult to interpret due to the scale and scope of the data collected. For actionable insights, GPS traces are usually reduced to one or more features that express the spatial phenomenon of interest. However, it is not always clear which spatial features should be employed, and substantial effort can be invested into designing features that may or may not provide insight. In this article, we present an alternative approach: a standardized feature set with actionable interpretations that can be efficiently run against many datasets. We show that these features can distinguish between disparate human mobility patterns, although no single feature can distinguish them alone.

BMC Public Health, 2019

Background: Urban form interventions can result in positive and negative impacts on physical acti... more Background: Urban form interventions can result in positive and negative impacts on physical activity, social participation, and well-being, and inequities in these outcomes. Natural experiment studies can advance our understanding of causal effects and processes related to urban form interventions. The INTErventions, Research, and Action in Cities Team (INTERACT) is a pan-Canadian collaboration of interdisciplinary scientists, urban planners, and public health decision makers advancing research on the design of healthy and sustainable cities for all. Our objectives are to use natural experiment studies to deliver timely evidence about how urban form interventions influence health, and to develop methods and tools to facilitate such studies going forward. Methods: INTERACT will evaluate natural experiments in four Canadian cities: the Arbutus Greenway in Vancouver, British Columbia; the All Ages and Abilities Cycling Network in Victoria, BC; a new Bus Rapid Transit system in Saskatoon, Saskatchewan; and components of the Sustainable Development Plan 2016-2020 in Montreal, Quebec, a plan that includes urban form changes initiated by the city and approximately 230 partnering organizations. We will recruit a cohort of between 300 and 3000 adult participants, age 18 or older, in each city and collect data at three time points. Participants will complete health and activity space surveys and provide sensor-based location and physical activity data. We will conduct qualitative interviews with a subsample of participants in each city. Our analysis methods will combine machine learning methods for detecting transportation mode use and physical activity, use temporal Geographic Information Systems to quantify changes to urban intervention exposure, and apply analytic methods for natural experiment studies including interrupted time series analysis. Discussion: INTERACT aims to advance the evidence base on population health intervention research and address challenges related to big data, knowledge mobilization and engagement, ethics, and causality. We will collect~100 TB of sensor data from participants over 5 years. We will address these challenges using interdisciplinary partnerships, training of highly qualified personnel, and modern methodologies for using sensor-based data.

PloS one, 2016

Characterizing how people move through space has been an important component of many disciplines.... more Characterizing how people move through space has been an important component of many disciplines. With the advent of automated data collection through GPS and other location sensing systems, researchers have the opportunity to examine human mobility at spatio-temporal resolution heretofore impossible. However, the copious and complex data collected through these logging systems can be difficult for humans to fully exploit, leading many researchers to propose novel metrics for encapsulating movement patterns in succinct and useful ways. A particularly salient proposed metric is the mobility entropy rate of the string representing the sequence of locations visited by an individual. However, mobility entropy rate is not scale invariant: entropy rate calculations based on measurements of the same trajectory at varying spatial or temporal granularity do not yield the same value, limiting the utility of mobility entropy rate as a metric by confounding inter-experimental comparisons. In th...

BMC Public Health, 2015

Background: Children can be highly active and highly sedentary on the same day! For instance, a c... more Background: Children can be highly active and highly sedentary on the same day! For instance, a child can spend a couple of hours playing sports, and then spend the rest of the day in front of a screen. A focus on examining both physical activity and sedentary behaviour throughout the day and in all seasons in a year is necessary to generate comprehensive evidence to curb childhood obesity. To achieve this, we need to understand where within a city are children active or sedentary in all seasons. This active living study based in Saskatoon, Canada, aims to understand the role played by modifiable urban built environments in mitigating, or exacerbating, seasonal effects on children's physical activity and sedentary behaviour in a population of children in transition from preadolescence to adolescence. Methods/Design: Designed as an observational, longitudinal investigation this study will recruit 800 Canadian children 10-14 years of age. Data will be obtained from children representing all socioeconomic categories within all types of neighbourhoods built in a range of urban designs. Built environment characteristics will be measured using previously validated neighbourhood audit and observational tools. Neighbourhood level socioeconomic variables customized to Saskatoon neighbourhoods from 2011 Statistics Canada's National Household Survey will be used to control for neighbourhood social environment. The validated Smart Cities Healthy Kids questionnaire will be administered to capture children's behaviour and perception of a range of factors that influence their activity, household (including family socioeconomic factors), parental, peer and neighbourhood influence on independent mobility. The outcome measures, different intensities of physical activity and sedentary behaviour, will be collected using global positioning system equipped accelerometers in all four seasons. Each accelerometry cycle will be matched with weather data obtained from Environment Canada. Extensive weather data will be accessed and classified into one of six distinct air mass categories for each day of accelerometry. Computational and spatial analytical techniques will be utilized to understand the multi-level influence of environmental exposures on physical activity and sedentary behaviour in all seasons.

Lecture Notes in Computer Science, 2011

Exergames encourage physical activity, but generally require specialized hardware and prescribed ... more Exergames encourage physical activity, but generally require specialized hardware and prescribed activities; whereas pervasive accumulated context exergames (PACEs) allow players to choose their type of exercise, but have limited depth of play. For mass commercialization of PACEs, facilitating long-term behavioural change, we propose two requirements: that PACEs support large-scale and flexible deployment; and that the design of PACEs support staying power through long-term playability. From these requirements, we motivate six PACE design principles and use these principles to develop a multiplayer roleplaying PACE. Results from a week-long study of our game showed that by satisfying the six design principles, we can create a PACE with scalability and staying power. Our results are the first step toward creating PACEs that promotes long-term game engagement, which is needed for activity-related behaviour change.

Proceedings of the International Academic Conference on the Future of Game Design and Technology - Futureplay '10, 2010

Obesity is a growing problem among children, due in part to their sedentary lifestyles. Time spen... more Obesity is a growing problem among children, due in part to their sedentary lifestyles. Time spent engaged in physical activity is decreasing, while time spent playing computer and video games is on the rise. We leverage children's interest in digital games to encourage families to engage in purposeful walking. We present a GPS-based game, played on a mobile device that uses walking as a primary gameplay mechanic. Our game, PiNiZoRo, includes a fighting game, triggered at points along a real-world route, and a map editor that allows parents and recreation specialists to create custom routes in their neighbourhoods. Results from an initial focus group with parents were positive, as they showed enthusiasm for the concept, implementation, and gameplay.

Proceedings of the International Academic Conference on the Future of Game Design and Technology - Futureplay '10, 2010

Heuristic evaluation-a technique where experts inspect software and determine where the applicati... more Heuristic evaluation-a technique where experts inspect software and determine where the application violates predetermined policies for good usability-is an effective technique for evaluating productivity software. The technique has recently been applied to video games, examining playability and usability for both single and multiplayer games. However, the severity ratings assigned to usability problems and used as a coarse categorization method for triage are still subjectively and somewhat arbitrarily assigned by evaluators, offering limited organizational value. In addition, they fail to account for the diversity found between games and game genres. In this paper we present a modified heuristic evaluation technique, which produces a prioritized list of heuristic violations based on the problem's frequency, impact, persistence, the heuristic it violates, and the game's genre. We evaluate our technique in a case study and show that the technique provides substantial value with little additional effort.

2013 26th IEEE Canadian Conference on Electrical and Computer Engineering (CCECE), 2013

This paper examines the problem of of developing a lossless compression scheme for data from a na... more This paper examines the problem of of developing a lossless compression scheme for data from a nano-satellite being developed by the University of Saskatchewan Space Design team, the USST-Sat. The benefit of compressing scientific data from the satellite will be an increased ability to perform experiments and downlink the results. Goals for the compression scheme are to maximize space savings and result in a net energy savings over storing and transmitting uncompressed data. Our evaluations show that the custom scheme that we developed, called USST-Compress, performs compression as well as or better than the generic compression schemes evaluated, and additionally results in better net energy savings.

Gaming Media and Social Effects, 2014

The use of general descriptive names, registered names, trademarks, service marks, etc. in this p... more The use of general descriptive names, registered names, trademarks, service marks, etc. in this publication does not imply, even in the absence of a specific statement, that such names are exempt from the relevant protective laws and regulations and therefore free for general use. While the advice and information in this book are believed to be true and accurate at the date of publication, neither the authors nor the editors nor the publisher can accept any legal responsibility for any errors or omissions that may be made. The publisher makes no warranty, express or implied, with respect to the material contained herein.

Lecture Notes in Computer Science, 2013

In presenting this thesis in partial fulfilment of the requirements for a Postgraduate degree fro... more In presenting this thesis in partial fulfilment of the requirements for a Postgraduate degree from the University of Saskatchewan, I agree that the Libraries of this University may make it freely available for inspection. I further agree that permission for copying of this thesis in any manner, in whole or in part, for scholarly purposes may be granted by the professor or professors who supervised my thesis work or, in their absence, by the Head of the Department or the Dean of the College in which my thesis work was done. It is understood that any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of Saskatchewan in any scholarly use which may be made of any material in my thesis.

Proceedings of the 17th ACM international conference on Modeling, analysis and simulation of wireless and mobile systems - MSWiM '14, 2014

Journal of Micromechanics and Microengineering, 2005

Micro fuel cell systems have elicited significant interest due to their promise for instantly rec... more Micro fuel cell systems have elicited significant interest due to their promise for instantly rechargeable, longer duration and portable power. Most micro fuel cell systems are either built as miniaturized plate-and-frame or silicon-based microelectromechanical systems (MEMS). Plate-and-frame systems are difficult to fabricate smaller than 20 cm 3. Existing micro fuel cell designs cannot meet the cost, scale and power requirements of some portable power markets. Traditional MEMS scaling advantages do not apply to fuel cells because the minimum area for the fuel cell is fixed by the catalyst area required for a given power output, and minimum volume set by mass transport limitations. We have developed a new hybrid technique that borrows from both micro and macro machining techniques to create fuel cells in the 1-20 cm 3 range, suitable for cell phones, PDAs and smaller devices.

IEEE Transactions on Systems, Man and Cybernetics, Part C (Applications and Reviews), 2000

This research describes the implementation of a vision-based algorithm that is capable of rapidly... more This research describes the implementation of a vision-based algorithm that is capable of rapidly determining robotic grasp points for planar objects. A representation of the target and a quadtree expansion generate candidate grasps that are compared using a cost function. The approach returns the first acceptable grasp point at a given tree resolution. The system has an execution time on the order of seconds and it is suitable for a large number of planar or near planar objects.

BMC Medical Informatics and Decision Making, 2012

Background The contact networks between individuals can have a profound impact on the evolution o... more Background The contact networks between individuals can have a profound impact on the evolution of an infectious outbreak within a network. The impact of the interaction between contact network and disease dynamics on infection spread has been investigated using both synthetic and empirically gathered micro-contact data, establishing the utility of micro-contact data for epidemiological insight. However, the infection models tied to empirical contact data were highly stylized and were not calibrated or compared against temporally coincident infection rates, or omitted critical non-network based risk factors such as age or vaccination status. Methods In this paper we present an agent-based simulation model firmly grounded in disease dynamics, incorporating a detailed characterization of the natural history of infection, and 13 weeks worth of micro-contact and participant health and risk factor information gathered during the 2009 H1N1 flu pandemic. Results We demonstrate that the mic...

BMC Medical Informatics and Decision Making, 2012

Background Microcontact datasets gathered automatically by electronic devices have the potential ... more Background Microcontact datasets gathered automatically by electronic devices have the potential augment the study of the spread of contagious disease by providing detailed representations of the study population’s contact dynamics. However, the impact of data collection experimental design on the subsequent simulation studies has not been adequately addressed. In particular, the impact of study duration and contact dynamics data aggregation on the ultimate outcome of epidemiological models has not been studied in detail, leaving the potential for erroneous conclusions to be made based on simulation outcomes. Methods We employ a previously published data set covering 36 participants for 92 days and a previously published agent-based H1N1 infection model to analyze the impact of contact dynamics representation on the simulated outcome of H1N1 transmission. We compared simulated attack rates resulting from the empirically recorded contact dynamics (ground truth), aggregated, typical d...

Remote Sensing, 2021

Unmanned aerial vehicle (UAV) imaging is a promising data acquisition technique for image-based p... more Unmanned aerial vehicle (UAV) imaging is a promising data acquisition technique for image-based plant phenotyping. However, UAV images have a lower spatial resolution than similarly equipped in field ground-based vehicle systems, such as carts, because of their distance from the crop canopy, which can be particularly problematic for measuring small-sized plant features. In this study, the performance of three deep learning-based super resolution models, employed as a pre-processing tool to enhance the spatial resolution of low resolution images of three different kinds of crops were evaluated. To train a super resolution model, aerial images employing two separate sensors co-mounted on a UAV flown over lentil, wheat and canola breeding trials were collected. A software workflow to pre-process and align real-world low resolution and high-resolution images and use them as inputs and targets for training super resolution models was created. To demonstrate the effectiveness of real-worl...

Proceedings 1999 IEEE International Conference on Robotics and Automation (Cat. No.99CH36288C)

Scientific Reports

2015 IEEE 40th Local Computer Networks Conference Workshops (LCN Workshops), 2015

International Journal of Environmental Research and Public Health, 2021

ACM Transactions on Spatial Algorithms and Systems, 2020

BMC Public Health, 2019

PloS one, 2016

BMC Public Health, 2015

Lecture Notes in Computer Science, 2011

Proceedings of the International Academic Conference on the Future of Game Design and Technology - Futureplay '10, 2010

2013 26th IEEE Canadian Conference on Electrical and Computer Engineering (CCECE), 2013

Gaming Media and Social Effects, 2014

Lecture Notes in Computer Science, 2013

Proceedings of the 17th ACM international conference on Modeling, analysis and simulation of wireless and mobile systems - MSWiM '14, 2014

Journal of Micromechanics and Microengineering, 2005

IEEE Transactions on Systems, Man and Cybernetics, Part C (Applications and Reviews), 2000

BMC Medical Informatics and Decision Making, 2012

Remote Sensing, 2021

Proceedings 1999 IEEE International Conference on Robotics and Automation (Cat. No.99CH36288C)