David Swanlund

David Swanlund

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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6 July 2020 in International Journal of Health Geographics
Verified
Journal Article
Open access
PDF file
DSDavid Swanlund
David Swanlund
NSNadine Schuurman
Nadine Schuurman
PZPaul Zandbergen
Paul Zandbergen
MBMariana Brussoni
Mariana Brussoni
Background: Geographic masks are techniques used to protect individual privacy in published maps but are highly under-utilized in research. This leads to continual violations of individual privacy, as sensitive health records are put at risk in unmasked maps. New approaches to geographic masking are required that foster accessibility and ease of use, such that they become more widely adopted. This article describes a new geographic masking method, called street masking, that reduces the burden on users of finding supplemental population data by instead automatically retrieving OpenStreetMap data and using the road network as a basis for masking. We compare it to donut geomasking, both with and without population density taken into account, to evaluate its efficacy against geographic masks that require slightly less and slightly more supplemental data. Our analysis is performed on synthetic data in three different Canadian cities. Results: Street masking performs similarly to population-based donut geomasking with regard to privacy protection, achieving comparable k-anonymity values at similar median displacement distances. As expected, distance-based donut geomasking performs worst at privacy protection. Street masking also performs very well regarding information loss, achieving far better cluster preservation and landcover agreement than population-based donut geomasking. Distance-based donut geomasking performs similarly to street masking, though at the cost of reduced privacy protection. Conclusion: Street masking competes with, if not out-performs population-based donut geomasking and does so without requiring any supplemental data from users. Moreover, unlike most other geographic masks, it significantly minimizes the risk of false attribution and inherently takes many geographic barriers into account. It is easily accessible for Python users and provides the foundation for interfaces to be built for non-coding users, such that privacy can be better protected in sensitive geospatial research.

15 December 2019 in Transactions in GIS
Verified
Journal Article
Closed access
PDF file
DSDavid Swanlund
David Swanlund
NSNadine Schuurman
Nadine Schuurman
MBMariana Brussoni
Mariana Brussoni

9 May 2016 in Annals of the American Association of Geographers
Verified
Journal Article
Closed access
DSDavid Swanlund
David Swanlund
NADINE SCHUURMANNADINE SCHUURMAN
NADINE SCHUURMAN
Recent revelations of dragnet surveillance by governments around the world have brought attention to privacy and surveillance in their many forms. In this article, we outline the technical mechanisms of geosurveillance to synthesize and inform on a constantly moving target. Despite their interconnections and overlap, to simplify and elucidate these geosurveillance mechanisms, we classify them into three parts: geolocation, unique identification, and the surveillance medium. We show that together they constitute a language that we, as subjects, did not choose yet are increasingly forced to negotiate. Moreover, these mechanisms are both numerous and highly complex and are only one component within large ecosystems of geosurveillance, making privacy ever more evasive. Understanding the mechanisms of our own subjection is integral to any prospects for intervention, however. As such, we highlight the Tor network as an example of resistance to geosurveillance that is enabled by acutely understanding the hypertechnical language that otherwise binds us. Indeed, as we emphasize throughout, mechanism matters.

4 September 2023 in Transactions in GIS
Verified
Journal Article
Open access
PSPankajeshwara Nand Sharma
Pankajeshwara Nand Sharma
MMMichael Martin
Michael Martin
DSDavid Swanlund
David Swanlund
Sensitive geographic data are invaluable assets for the people to whom they belong and their disclosure should be decided by the sovereign data owner (SDO). Due to several high‐profile data breaches and business models that commercialize user data, the need for new approaches to geoprivacy and data sovereignty has grown. We propose MapSafe, a client web application that first obfuscates datasets using donut masking or hexagonal binning, separately, and thereafter implements a multi‐level encryption scheme that permits SDOs to share the final encrypted volume containing the geospatial information when they choose and at a level of detail which they are comfortable. The authenticity verification of the volume is facilitated by storing the hash value corresponding to the encrypted volume immutably on the Blockchain as a public record. Our approach places geoprivacy under data guardians'’ control, and its integration capabilities promote its adoption in existing and future geospatial web systems.

NADINE SCHUURMANNADINE SCHUURMAN
NADINE SCHUURMAN
BWBlake Walker
Blake Walker
DSDavid Swanlund
David Swanlund
ofer amramofer amram
ofer amram
NYNatalie Yanchar
Natalie Yanchar
Road traffic injuries constitute a significant global health burden; the World Health Organization estimates that they result in 1.35 million deaths annually. While most pedestrian injury studies rely predominantly on statistical modelling, this paper argues for a mixed-methods approach combining spatial analysis, environmental scans, and local knowledge for assessing environmental risk factors. Using data from the Nova Scotia Trauma Registry, severe pedestrian injury cases and ten corresponding hotspots were mapped across the Halifax Regional Municipality. Using qualitative observation, quantitative environmental scans, and a socioeconomic deprivation index, we assessed hotspots over three years to identify key social- and built-environmental correlates. Injuries occurred in a range of settings; however, clear patterns were not observed based on land use, age, or socio-economic status (SES) alone. Three hotspots revealed an association between elevated pedestrian injury and a pattern of geographic, environmental, and socio-economic factors: low- to middle-SES housing separated from a roadside attraction by several lanes of traffic, and blind hills/bends. An additional generalized scenario was constructed representing common risk factors across all hotspots. This study is unique in that it moves beyond individual measures (e.g., statistical, environmental scans, or geographic information systems (GIS) mapping) to combine all three methods toward identifying environmental features associated with pedestrian motor vehicle crashes (PMVC).

BWBlake Walker
Blake Walker
CSCléssio Moura de Souza
Cléssio Moura de Souza
Enrique PedrosoEnrique Pedroso
Enrique Pedroso
RLRyan Lai
Ryan Lai
Paige HunterPaige Hunter
Paige Hunter
KBKevan Guilherme Nóbrega Barbosa
Kevan Guilherme Nóbrega Barbosa
This paper presents an empirically grounded call for a more nuanced engagement and situatedness with placial characteristics within a spatial epidemiology frame. By using qualitative data collected through interviews and observation to parameterise standard and spatial regression models, and through a critical interpretation of their results, we present initial inroads for a situated spatial epidemiology and an analytical framework for health/medical geographers to iteratively engage with data, modelling, and the context of both the subject and process of analysis. In this study, we explore the socioeconomic factors that influence homicide rates in the Brazilian state of Alagoas from a critical public health perspective. Informed by field observation and interviews with 24 youths in low-income neighbourhoods and prisons in Alagoas, we derive and critically reflect on three regression models to predict municipal homicide rates from 2016–2020. The model results indicate significant effects for the male population, persons without elementary school completion, households with reported income, divorced persons, households without piped water, and persons working outside their home municipality. These results are situated in the broader socioeconomic context, trajectories, and cycles of inequality in the study area and underscore the need for integrative and contextually engaged mixed method study design in spatial epidemiology.