42 results on '"Olle Järv"'
Search Results
2. Activity Spaces and Big Data Sources in Segregation Research: A Methodological Review
- Author
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Kerli Müürisepp, Olle Järv, Tiit Tammaru, and Tuuli Toivonen
- Subjects
spatial segregation ,activity space ,human mobility ,methodological review ,big data ,literature review ,Science (General) ,Q1-390 ,Social sciences (General) ,H1-99 - Abstract
The activity space approach is increasingly mobilized in spatial segregation research to broaden its scope from residential neighborhoods to other socio-spatial contexts of people. Activity space segregation research is an emerging field, characterized by quick adaptation of novel data sources and interdisciplinary methodologies. In this article, we present a methodological review of activity space segregation research by identifying approaches, methods and data sources applied. First, our review highlights that the activity space approach enables segregation to be studied from the perspectives of people, places and mobility flows. Second, the results reveal that both traditional data sources and novel big data sources are valuable for studying activity space segregation. While traditional sources provide rich background information on people for examining the social dimension of segregation, big data sources bring opportunities to address temporality, and increase the spatial extent and resolution of analysis. Hence, big data sources have an important role in mediating the conceptual change from a residential neighborhood-based to an activity space-based approach to segregation. Still, scholars should address carefully the challenges and uncertainties that big data entail for segregation studies. Finally, we propose a framework for a three-step methodological workflow for activity space segregation analysis, and outline future research avenues to move toward more conceptual clarity, integrated analysis framework and methodological rigor.
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- 2022
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3. COVID-19 is spatial: Ensuring that mobile Big Data is used for social good
- Author
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Age Poom, Olle Järv, Matthew Zook, and Tuuli Toivonen
- Subjects
General Works - Abstract
The mobility restrictions related to COVID-19 pandemic have resulted in the biggest disruption to individual mobilities in modern times. The crisis is clearly spatial in nature, and examining the geographical aspect is important in understanding the broad implications of the pandemic. The avalanche of mobile Big Data makes it possible to study the spatial effects of the crisis with spatiotemporal detail at the national and global scales. However, the current crisis also highlights serious limitations in the readiness to take the advantage of mobile Big Data for social good, both within and beyond the interests of health sector. We propose two strategical pathways for the future use of mobile Big Data for societal impact assessment, addressing access to both raw mobile Big Data as well as aggregated data products. Both pathways require careful considerations of privacy issues, harmonized and transparent methodologies, and attention to the representativeness, reliability and continuity of data. The goal is to be better prepared to use mobile Big Data in future crises.
- Published
- 2020
- Full Text
- View/download PDF
4. Escaping from Cities during the COVID-19 Crisis: Using Mobile Phone Data to Trace Mobility in Finland
- Author
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Elias Willberg, Olle Järv, Tuomas Väisänen, and Tuuli Toivonen
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COVID-19 ,mobile phone data ,human mobility ,multi-local living ,dynamic population ,Geography (General) ,G1-922 - Abstract
The coronavirus disease 2019 (COVID-19) crisis resulted in unprecedented changes in the spatial mobility of people across societies due to the restrictions imposed. This also resulted in unexpected mobility and population dynamics that created a challenge for crisis preparedness, including the mobility from cities during the crisis due to the underlying phenomenon of multi-local living. People changing their residences can spread the virus between regions and create situations in which health and emergency services are not prepared for the population increase. Here, our focus is on urban–rural mobility and the influence of multi-local living on population dynamics in Finland during the COVID-19 crisis in 2020. Results, based on three mobile phone datasets, showed a significant drop in inter-municipal mobility and a shift in the presence of people—a population decline in urban centres and an increase in rural areas, which is strongly correlated to secondary housing. This study highlights the need to improve crisis preparedness by: (1) acknowledging the growing importance of multi-local living, and (2) improving the use of novel data sources for monitoring population dynamics and mobility. Mobile phone data products have enormous potential, but attention should be paid to the varying methodologies and their possible impact on analysis.
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- 2021
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5. Mobile phones in a traffic flow: a geographical perspective to evening rush hour traffic analysis using call detail records.
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Olle Järv, Rein Ahas, Erki Saluveer, Ben Derudder, and Frank Witlox
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Medicine ,Science - Abstract
Excessive land use and suburbanisation around densely populated urban areas has gone hand in hand with a growth in overall transportation and discussions about causality of traffic congestions. The objective of this paper is to gain new insight regarding the composition of traffic flows, and to reveal how and to what extent suburbanites' travelling affects rush hour traffic. We put forward an alternative methodological approach using call detail records of mobile phones to assess the composition of traffic flows during the evening rush hour in Tallinn, Estonia. We found that daily commuting and suburbanites influence transportation demand by amplifying the evening rush hour traffic, although daily commuting trips comprises only 31% of all movement at that time. The geography of the Friday evening rush hour is distinctive from other working days, presumably in connection with domestic tourism and leisure time activities. This suggests that the rise of the overall mobility of individuals due to societal changes may play a greater role in evening rush hour traffic conditions than does the impact of suburbanisation.
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- 2012
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6. Detecting country of residence from social media data: a comparison of methods.
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Vuokko Heikinheimo, Olle Järv, Henrikki Tenkanen, Tuomo Hiippala, and Tuuli Toivonen
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- 2022
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7. The impact of COVID-19 on daily lives of transnational people based on smartphone data: Estonians in Finland.
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Olle Järv, Ago Tominga, Kerli Müürisepp, and Siiri Silm
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- 2021
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8. Mapping urban linguistic diversity with social media and population register data.
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Tuomas Väisänen, Olle Järv, Tuuli Toivonen, and Tuomo Hiippala
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- 2022
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9. Enhancing spatial accuracy of mobile phone data using multi-temporal dasymetric interpolation.
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Olle Järv, Henrikki Tenkanen, and Tuuli Toivonen
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- 2017
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10. Revealing mobilities of people to understand cross-border regions: insights from Luxembourg using social media data
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Olle Järv, Håvard W. Aagesen, Tuomas Väisänen, and Samuli Massinen
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Geography, Planning and Development - Published
- 2022
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11. The effect of COVID-19 on cross-border mobilities of people and functional border regions: the Nordic case study from Twitter data
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Olle Järv, Håvard Wallin Aagesen, and Philippe Gerber
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Geography, Planning and Development - Published
- 2022
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12. Segregation and the pandemic : The dynamics of daytime social diversity during COVID-19 in Greater Stockholm
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Kerli Müürisepp, Olle Järv, Feliks Sjöblom, Marina Toger, John Östh, Digital Geography Lab, Helsinki Institute of Urban and Regional Studies (Urbaria), and Department of Geosciences and Geography
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Sweden ,Human mobility ,Geography, Planning and Development ,COVID-19 ,Mobile phone data ,Forestry ,Ekonomisk geografi ,Economic Geography ,3142 Public health care science, environmental and occupational health ,5142 Social policy ,519 Social and economic geography ,Tourism, Leisure and Hospitality Management ,Socio-spatial diversity ,Daytime segregation ,General Environmental Science - Abstract
In this study, we set out to understand how the changes in daily mobility of people during the first wave of the COVID-19 pandemic in spring 2020 influenced daytime spatial segregation. Rather than focusing on spatial separation, we approached this task from the perspective of daytime socio-spatial diversity – the degree to which people from socially different neighbourhoods share urban space during the day. By applying mobile phone data from Greater Stockholm, Sweden, the study examines weekly changes in 1) daytime social diversity across different types of neighbourhoods, and 2) population groups' exposure to diversity in their main daytime activity locations. Our findings show a decline in daytime diversity in neighbourhoods when the pandemic broke out in mid-March 2020. The decrease in diversity was marked in urban centres, and significantly different in neighbourhoods with different socio-economic and ethnic compositions. Moreover, the decrease in people's exposure to diversity in their daytime activity locations was even more profound and long-lasting. In particular, isolation from diversity increased more among residents of high-income majority neighbourhoods than of low-income minority neighbourhoods. We conclude that while some COVID-19-induced changes might have been temporary, the increased flexibility in where people work and live might ultimately reinforce both residential and daytime segregation.
- Published
- 2023
13. Mapping the languages of Twitter in Finland
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Olle Järv, Tuomas Lauri Aleksanteri Väisänen, Tuomo Hiippala, and Tuuli Toivonen
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060201 languages & linguistics ,0508 media and communications ,Spacetime ,Ecology ,media_common.quotation_subject ,0602 languages and literature ,05 social sciences ,050801 communication & media studies ,06 humanities and the arts ,Species richness ,Sociology ,Diversity (politics) ,media_common - Abstract
Twitter is a popular social media platform for scholarly research, because the user-generated content on the platform can also include geographic and temporal information. We collect a corpus of 38 million Twitter messages with two million geographical coordinates to map the languages used across Finland at the level of regions and municipalities. To cope with the high volume of social media data, we use automatic language identification and place of residence detection. We estimate the linguistic richness and diversity of users and locations using measures developed within ecology and information sciences. The analyses reveal a rich, multilingual environment that varies geographically and temporally, particularly between coastal, rural and urban areas. The results, which underline the mutual benefits of collaboration between linguists and geographers, provide a more fine-grained, accurate and comprehensive view of the languages used on Twitter in Finland than previously available.
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- 2020
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14. The Link Between Ethnic Segregation and Socio‐Economic Status: An Activity Space Approach
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Siiri Silm, Rein Ahas, Anu Masso, Olle Järv, Digital Geography Lab, and Department of Geosciences and Geography
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1171 Geosciences ,Economics and Econometrics ,activity space ,Inequality ,mobile phone data ,socio-economic status ,media_common.quotation_subject ,Geography, Planning and Development ,0211 other engineering and technologies ,0507 social and economic geography ,Ethnic group ,DISADVANTAGE ,SOCIOSPATIAL ISOLATION ,02 engineering and technology ,Space (commercial competition) ,Social class ,socio-spatial inequality ,Phenomenon ,human mobility ,EXPOSURE ,Economic geography ,HOME ,10. No inequality ,Socioeconomic status ,SOCIAL-CLASS ,media_common ,GEOGRAPHIES ,05 social sciences ,Perspective (graphical) ,021107 urban & regional planning ,segregation ,NEIGHBORHOOD ,Geography ,519 Social and economic geography ,COMMUNITIES ,INEQUALITY ,INTEGRATION ,050703 geography ,Social status - Abstract
The extent to which ethnic segregation results from differences in socio-economic factors remains a seminal topic of debate. The growing literature demonstrating the multifaceted phenomenon of segregation urges more focus on individuals' spatial and social interactions. We applied an activity space approach and considered ethnic differences in individuals' activity spaces as an indicator of spatial segregation. We used mobile phone and survey datasets in Estonia. We show that place-based segregation indices derived from both datasets indicate similar levels of ethnic segregation. From an activity space perspective, the results show that the main socio-economic factor affecting the extensity of activity spaces is self-estimated social status rather than education and income. Results show that ethnic inequality in spatial behaviour is not straightforward, but rather that it is linked to how individuals position themselves in society. We argue that socio-economic factors need to be controlled to examine ethnic segregation from activity space perspective.
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- 2020
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15. Social media data for conservation science: A methodological overview
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Tuomo Hiippala, Anna Hausmann, Vuokko Vilhelmiina Heikinheimo, Christoph Fink, Henrikki Tenkanen, Olle Järv, Tuuli Toivonen, and Enrico Di Minin
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0106 biological sciences ,Computer science ,business.industry ,010604 marine biology & hydrobiology ,Big data ,15. Life on land ,Space (commercial competition) ,010603 evolutionary biology ,01 natural sciences ,Data science ,13. Climate action ,Content analysis ,Anthropocene ,Information source ,Conservation science ,Social media ,business ,Ecology, Evolution, Behavior and Systematics ,Nature and Landscape Conservation ,Grand Challenges - Abstract
Improved understanding of human-nature interactions is crucial to conservation science and practice, but collecting relevant data remains challenging. Recently, social media have become an increasingly important source of information on human-nature interactions. However, the use of advanced methods for analysing social media is still limited, and social media data are not used to their full potential. In this article, we present available sources of social media data and approaches to mining and analysing these data for conservation science. Specifically, we (i) describe what kind of relevant information can be retrieved from social media platforms, (ii) provide a detailed overview of advanced methods for spatio-temporal, content and network analyses, (iii) exemplify the potential of these approaches for real-world conservation challenges, and (iv) discuss the limitations of social media data analysis in conservation science. Combined with other data sources and carefully considering the biases and ethical issues, social media data can provide a complementary and cost-efficient information source for addressing the grand challenges of biodiversity conservation in the Anthropocene epoch.
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- 2019
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16. Käigud Soome ja Eesti vahel – tuhandete püsieluviis
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Olle Järv, Siiri Silm, Digital Geography Lab, Kaupunkitutkimusinstituutti (Urbaria), and Avdelningen för geovetenskaper och geografi
- Subjects
519 Social and economic geography - Published
- 2021
17. The impact of COVID-19 on daily lives of transnational people based on smartphone data : Estonians in Finland
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Siiri Silm, Olle Järv, Ago Tominga, Kerli Müürisepp, Digital Geography Lab, Helsinki Institute of Urban and Regional Studies (Urbaria), Department of Geosciences and Geography, and Helsinki Institute of Sustainability Science (HELSUS)
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1171 Geosciences ,2019-20 coronavirus outbreak ,Economic growth ,Coronavirus disease 2019 (COVID-19) ,Mobilities ,Computer Networks and Communications ,Computer science ,MIGRATION ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,0211 other engineering and technologies ,0507 social and economic geography ,SPACES ,02 engineering and technology ,Affect (psychology) ,MOBILE POSITIONING DATA ,MOBILITIES ,Pandemic ,Social media ,human mobility ,Electrical and Electronic Engineering ,smartphone tracking ,SOCIAL MEDIA ,05 social sciences ,COVID-19 ,021107 urban & regional planning ,social interaction ,transnational people ,Social relation ,519 Social and economic geography ,Signal Processing ,050703 geography - Abstract
Global crises such as the COVID-19 pandemic affect both the functioning of our societies and the daily lives of people. Yet the impact of the crisis and its mitigation measures have exerted disproportionate influence on different population groups. In March – May 2020, COVID-19 mitigation measures such as closures of national borders affected transnational people who cross borders frequently for work, shopping, services, family reasons and socialising. We have examined the influence of the COVID-19 pandemic on the daily lives of transnational Estonians residing in Finland, based on a unique longitudinal smartphone tracking survey. Findings show that besides a drastic but expected decrease in trans-nationals’ spatial mobility, the pandemic has especially affected their cross-border mobility patterns to and time spent in Estonia. Interestingly, during the lockdown, some transnationals decided to stay not in their primary home in Finland, but in Estonia. Mobile phone communication activity followed moderately the downward trend of spatial mobility, but the crisis changed the division of communication partners by country: Finnish contacts diminished, whereas Estonian partners remained active. We reflect on our findings for future research and discuss the applicability of the smart-phone tracking approach for capturing the socio-spatial interactions of transnational people.
- Published
- 2021
18. Understanding the use of urban green spaces from user-generated geographic information
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Claudia Bergroth, Vuokko Vilhelmiina Heikinheimo, Tuomo Hiippala, Tuuli Toivonen, Henrikki Tenkanen, Olle Järv, Department of Geosciences and Geography, Helsinki Institute of Sustainability Science (HELSUS), Digital Geography Lab, English Philology, and Department of Languages
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Public participation GIS ,Computer science ,CITIES ,Automatic identification and data capture ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,Management, Monitoring, Policy and Law ,DATA-COLLECTION ,01 natural sciences ,SOCIAL-MEDIA DATA ,MOBILE POSITIONING DATA ,Social media data ,SPATIAL ACCURACY ,Urban planning ,PUBLIC-PARTICIPATION GIS ,11. Sustainability ,Social media ,1172 Environmental sciences ,0105 earth and related environmental sciences ,Nature and Landscape Conservation ,Data collection ,Ecology ,Mobile phone operator ,Urban green space ,Mobile phone data ,021107 urban & regional planning ,16. Peace & justice ,Data science ,Urban Studies ,PHYSICAL-ACTIVITY ,PPGIS ,Sports tracking data ,13. Climate action ,Mobile phone ,519 Social and economic geography ,DENSIFICATION ,5171 Political Science ,HEALTH ,Mobile device - Abstract
Parks and other green spaces are an important part of sustainable, healthy and socially equal urban environment. Urban planning and green space management benefit from information about green space use and values, but such data are often scarce and laborious to collect. Temporally dynamic geographic information generated by different mobile devices and social media platforms are a promising source of data for studying green spaces. User-generated data have, however, platform specific characteristics that limit their potential use. In this article, we compare the ability of different user-generated data sets to provide information on where, when and how people use and value urban green spaces. We compare four types of data: social media, sports tracking, mobile phone operator and public participation geographic information systems (PPGIS) data in a case study from Helsinki, Finland. Our results show that user-generated geographic information sources provide useful insights about being in, moving through and perceiving urban green spaces, as long as evident limitations and sample biases are acknowledged. Social media data highlight patterns of leisure time activities and allow further content analysis. Sports tracking data and mobile phone data capture green space use at different times of the day, including commuting through the parks. PPGIS studies allow asking specific questions from active participants, but might be limited in spatial and temporal extent. Combining information from multiple user-generated data sets complements traditional data sources and provides a more comprehensive understanding of green space use and preferences.
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- 2020
19. Tracing human mobilities through mobile phones
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Olle Järv, Siiri Silm, and Anu Masso
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Mobilities ,Computer science ,Computer graphics (images) ,Tracing - Published
- 2020
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20. COVID-19 is spatial: Ensuring that mobile Big Data is used for social good
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Tuuli Toivonen, Matthew Zook, Olle Järv, and Age Poom
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Information Systems and Management ,Coronavirus disease 2019 (COVID-19) ,Data products ,Mobilities ,Reliability (computer networking) ,Big data ,0211 other engineering and technologies ,0507 social and economic geography ,lcsh:A ,02 engineering and technology ,Library and Information Sciences ,Representativeness heuristic ,Spatial data infrastructure ,business.industry ,Communication ,05 social sciences ,Societal impact of nanotechnology ,COVID-19 ,spatial data infrastructure ,021107 urban & regional planning ,Data science ,mobility ,3. Good health ,Computer Science Applications ,Commentary ,lcsh:General Works ,Mobile Big Data ,business ,mobile phone data, social media data, privacy ,050703 geography ,Information Systems ,social good - Abstract
The mobility restrictions related to COVID-19 pandemic have resulted in the biggest disruption to individual mobilities in modern times. The crisis is clearly spatial in nature, and examining the geographical aspect is important in understanding the broad implications of the pandemic. The avalanche of mobile Big Data makes it possible to study the spatial effects of the crisis with spatiotemporal detail at the national and global scales. However, the current crisis also highlights serious limitations in the readiness to take the advantage of mobile Big Data for social good, both within and beyond the interests of health sector. We propose two strategical pathways for the future use of mobile Big Data for societal impact assessment, addressing access to both raw mobile Big Data as well as aggregated data products. Both pathways require careful considerations of privacy issues, harmonized and transparent methodologies, and attention to the representativeness, reliability and continuity of data. The goal is to be better prepared to use mobile Big Data in future crises.
- Published
- 2020
21. Sotsiaalmeedia andmete sotsiaal-ruumiline analüüs
- Author
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Olle Järv, Kerli Müürisepp, Masso, Anu, Tiidenberg, Katrin, Siibak, Andra, Digital Geography Lab, Kaupunkitutkimusinstituutti (Urbaria), Avdelningen för geovetenskaper och geografi, Centret för hållbarhetsvetenskap (HELSUS), Avdelningen för stadsgeografi och regionala studier, and Helsinki Inequality Initiative (INEQ)
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519 Social and economic geography ,education ,5141 Sociology ,113 Computer and information sciences - Published
- 2020
22. Mobiiltelefonid ühiskonna aegruumilises analüüsis
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Siiri Silm, Olle Järv, Masso, Anu, Tiidenberg, Katrin, Siibak, Andra, Digital Geography Lab, Kaupunkitutkimusinstituutti (Urbaria), Avdelningen för geovetenskaper och geografi, Centret för hållbarhetsvetenskap (HELSUS), and Avdelningen för stadsgeografi och regionala studier
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519 Social and economic geography ,5141 Sociology ,113 Computer and information sciences - Published
- 2020
23. Dynamic cities: Location-based accessibility modelling as a function of time
- Author
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Tuuli Toivonen, Rein Ahas, Henrikki Tenkanen, Olle Järv, Maria Salonen, Department of Geosciences and Geography, and Digital Geography Lab
- Subjects
1171 Geosciences ,Multimodal transport ,Travel time ,SERVICE DELIVERY ,Mobilities ,Geography, Planning and Development ,Big data ,Transport network ,0211 other engineering and technologies ,SOCIAL EXCLUSION ,Context (language use) ,02 engineering and technology ,Spatial equity ,11. Sustainability ,0502 economics and business ,SPACE ,General Environmental Science ,Mobility ,public transport ,050210 logistics & transportation ,dynamic accessibility ,LAND-USE ,business.industry ,05 social sciences ,021107 urban & regional planning ,Forestry ,TRAVEL-TIMES ,Space-time modelling ,Data science ,Urban structure ,Geography ,Conceptual framework ,Tourism, Leisure and Hospitality Management ,Public transport ,HEALTH-CARE ,OPENING HOURS ,EQUITY ,business ,MOBILE PHONE DATA - Abstract
The concept of accessibility – the potential of opportunities for interaction – binds together the key physical components of urban structure: people, transport and social activity locations. Most often these components are dynamic in nature and hence the accessibility landscape changes in space and time based on people's mobilities and the temporality of the transport network and activity locations (e.g. services). Person-based accessibility approaches have been successful in incorporating time and space in the analyses and models. Still, the more broadly applied location-based accessibility modelling approaches have, on the other hand, often been static/atemporal in their nature. Here, we present a conceptual framework of dynamic location-based accessibility modelling that captures the dynamic temporality of all three accessibility components. Furthermore, we empirically test the proposed framework using novel data sources and tools. We demonstrate the impact of temporal aspects in accessibility modelling with two examples: by investigating food accessibility and its spatial equity. Our case study demonstrates how the conventional static location-based accessibility models tend to overestimate the access of people to potential opportunities. The proposed framework is universally applicable beyond the urban context, from local to global scale and on different temporal scales and multimodal transport systems. It also bridges the gap between location-based accessibility and person-based accessibility research. The concept of accessibility- the potential of opportunities for interaction- binds together the key physical components of urban structure: people, transport and social activity locations. Most often these components are dynamic in nature and hence the accessibility landscape changes in space and time based on people's mobilities and the temporality of the transport network and activity locations (e.g. services). Person-based accessibility approaches have been successful in incorporating time and space in the analyses and models. Still, the more broadly applied location-based accessibility modelling approaches have, on the other hand, often been static/atemporal in their nature. Here, we present a conceptual framework of dynamic location-based accessibility modelling that captures the dynamic temporality of all three accessibility components. Furthermore, we empirically test the proposed framework using novel data sources and tools. We demonstrate the impact of temporal aspects in accessibility modelling with two examples: by investigating food accessibility and its spatial equity. Our case study demonstrates how the conventional static location-based accessibility models tend to overestimate the access of people to potential opportunities. The proposed framework is universally applicable beyond the urban context, from local to global scale and on different temporal scales and multimodal transport systems. It also bridges the gap between location-based accessibility and person-based accessibility research.
- Published
- 2018
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24. Enhancing spatial accuracy of mobile phone data using multi-temporal dasymetric interpolation
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Henrikki Tenkanen, Olle Järv, Tuuli Toivonen, Department of Geosciences and Geography, Digital Geography Lab, Division of Urban Geography and Regional Studies, Ecology and Evolutionary Biology, and C-BIG Conservation Biology Informatics Group
- Subjects
Computer science ,Geography, Planning and Development ,Population ,0211 other engineering and technologies ,0507 social and economic geography ,02 engineering and technology ,Library and Information Sciences ,computer.software_genre ,spatio-temporal data modelling ,Multivariate interpolation ,Base station ,Dasymetric map ,education ,call detail records ,education.field_of_study ,05 social sciences ,Mobile phone data ,021107 urban & regional planning ,Ancillary data ,dasymetric modelling ,Mobile phone ,519 Social and economic geography ,Cellular network ,spatial interpolation ,Data mining ,050703 geography ,Mobile device ,computer ,Information Systems - Abstract
Novel digital data sources allow us to attain enhanced knowledge about locations and mobilities of people in space and time. Already a fast-growing body of literature demonstrates the applicability and feasibility of mobile phone-based data in social sciences for considering mobile devices as proxies for people. However, the implementation of such data imposes many theoretical and methodological challenges. One major issue is the uneven spatial resolution of mobile phone data due to the spatial configuration of mobile network base stations and its spatial interpolation. To date, different interpolation techniques are applied to transform mobile phone data into other spatial divisions. However, these do not consider the temporality and societal context that shapes the human presence and mobility in space and time. The paper aims, first, to contribute to mobile phone-based research by addressing the need to give more attention to the spatial interpolation of given data, and further by proposing a dasymetric interpolation approach to enhance the spatial accuracy of mobile phone data. Second, it contributes to population modelling research by combining spatial, temporal and volumetric dasymetric mapping and integrating it with mobile phone data. In doing so, the paper presents a generic conceptual framework of a multi-temporal function-based dasymetric (MFD) interpolation method for mobile phone data. Empirical results demonstrate how the proposed interpolation method can improve the spatial accuracy of both night-time and daytime population distributions derived from different mobile phone data sets by taking advantage of ancillary data sources. The proposed interpolation method can be applied for both location- and person-based research, and is a fruitful starting point for improving the spatial interpolation methods for mobile phone data. We share the implementation of our method in GitHub as open access Python code.
- Published
- 2017
25. Ethnic differences in activity spaces as a characteristic of segregation: A study based on mobile phone usage in Tallinn, Estonia
- Author
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Rein Ahas, Olle Järv, Ben Derudder, Frank Witlox, and Kerli Müürisepp
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Mobilities ,business.industry ,Ethnic group ,Distribution (economics) ,Environmental Science (miscellaneous) ,Estonian ,language.human_language ,Urban Studies ,Cohesion (linguistics) ,Geography ,Mobile phone ,Spatial mobility ,language ,Economic geography ,business ,Spatial extent ,Demography - Abstract
Given ongoing developments altering social and spatial cohesion in urban societies, a more comprehensive understanding of segregation is needed. Taking the ‘mobilities turn’ at heart, we move beyond place-based segregation approaches and focus on the practised urban experiences of individuals through a more comprehensive assessment of their activity spaces. This study contributes to people-based segregation research by mapping the activity spaces of individuals on the basis of mobile phone data in Tallinn (Estonia) and relating these activity spaces to (mainly) the users’ ethnic background (i.e. Estonian versus Russian). Significant ethnic differences in terms of (1) the number of activity locations, (2) the geographical distribution of these locations, and (3) the overall spatial extent of activity spaces are found. We also find that these differences tend to deepen as the temporal framework is extended. We discuss the main implications for segregation research and highlight some avenues for further research.
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- 2014
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26. Understanding monthly variability in human activity spaces: A twelve-month study using mobile phone call detail records
- Author
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Frank Witlox, Olle Järv, and Rein Ahas
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Data collection ,Perspective (graphical) ,Transportation ,Time geography ,Variance (accounting) ,Computer Science Applications ,Travel behavior ,Geography ,Mobile phone ,Automotive Engineering ,Set (psychology) ,Simulation ,Civil and Structural Engineering ,Demography ,Intrapersonal communication - Abstract
Human activity-travel behaviour (ATB) is a complex pattern of paths and activities in space and time. Studies indicate that ATB is the construction of daily habitual, weekly, monthly and seasonal routines together with strong variety seeking behaviour. Daily habitual travel patterns are usually taken as a basis, but for transportation planners more knowledge is needed on longitudinal trends in human ATB. Empirical data on prolonged perspective are hard to come by while mobile phone based call detail records could be one means of narrowing this research gap. By implementing this method, the present study attempts to provide new insights on individual monthly spatial travel behaviour. Using call detail records obtained from a set of anonymous mobile phone users, we examined their activity locations and activity spaces for 12 consecutive months. We found modest monthly variation in the number of activity locations, whereas there were great variations in the sizes of individual activity spaces. The monthly variation in individual spatial behaviour is explained up to 17% by seasonality, although the variance is predominantly attributed to individual factors and results indicate significant intrapersonal monthly variability. Findings suggest new avenues for future work on ATB from a longitudinal perspective.
- Published
- 2014
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27. PhD news
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Hannes Ling, Jüri Kivimaa, Karen Voolaid, Liina Randmann, Marina Järvis, and Olle Järv
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Political Science and International Relations ,General Economics, Econometrics and Finance - Published
- 2013
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28. Health research needs more comprehensive accessibility measures: integrating time and transport modes from open data
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Henrikki Tenkanen, Perttu Saarsalmi, Tuuli Toivonen, Maria Salonen, Olle Järv, Department of Geosciences and Geography, Division of Urban Geography and Regional Studies, Ecology and Evolutionary Biology, C-BIG Conservation Biology Informatics Group, and Digital Geography Lab
- Subjects
Service (systems architecture) ,Travel time ,General Computer Science ,Computer science ,Health geography ,Business, Management and Accounting(all) ,0507 social and economic geography ,Temporality ,Food Supply ,Multimodality ,Transport engineering ,03 medical and health sciences ,0302 clinical medicine ,11. Sustainability ,Door-to-door approach ,030212 general & internal medicine ,Mode of transport ,Private car ,business.industry ,Research ,Open data ,05 social sciences ,Public Health, Environmental and Occupational Health ,Models, Theoretical ,Accessibility ,General Business, Management and Accounting ,Metropolitan area ,3142 Public health care science, environmental and occupational health ,Socioeconomic Factors ,Health ,Food ,519 Social and economic geography ,Public transport ,Multimodal ,1181 Ecology, evolutionary biology ,Spatio-temporal ,business ,050703 geography ,Needs Assessment ,Computer Science(all) - Abstract
Background In this paper, we demonstrate why and how both temporality and multimodality should be integrated in health related studies that include accessibility perspective, in this case healthy food accessibility. We provide evidence regarding the importance of using multimodal spatio-temporal accessibility measures when conducting research in urban contexts and propose a methodological approach for integrating different travel modes and temporality to spatial accessibility analyses. We use the Helsinki metropolitan area (Finland) as our case study region to demonstrate the effects of temporality and modality on the results. Methods Spatial analyses were carried out on 250 m statistical grid squares. We measured travel times between the home location of inhabitants and open grocery stores providing healthy food at 5 p.m., 10 p.m., and 1 a.m. using public transportation and private cars. We applied the so-called door-to-door approach for the travel time measurements to obtain more realistic and comparable results between travel modes. The analyses are based on open access data and publicly available open-source tools, thus similar analyses can be conducted in urban regions worldwide. Results Our results show that both time and mode of transport have a prominent impact on the outcome of the analyses; thus, understanding the realities of accessibility in a city may be very different according to the setting of the analysis used. In terms of travel time, there is clear variation in the results at different times of the day. In terms of travel mode, our results show that when analyzed in a comparable manner, public transport can be an even faster mode than a private car to access healthy food, especially in central areas of the city where the service network is dense and public transportation system is effective. Conclusions This study demonstrates that time and transport modes are essential components when modeling health-related accessibility in urban environments. Neglecting them from spatial analyses may lead to overly simplified or even erroneous images of the realities of accessibility. Hence, there is a risk that health related planning and decisions based on simplistic accessibility measures might cause unwanted outcomes in terms of inequality among different groups of people.
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- 2016
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29. Using Mobile Positioning Data to Model Locations Meaningful to Users of Mobile Phones
- Author
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Margus Tiru, Siiri Silm, Erki Saluveer, Rein Ahas, and Olle Järv
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Multimedia ,business.industry ,Mobile computing ,Mobile Web ,computer.software_genre ,Urban Studies ,Public land mobile network ,Location-based service ,Mobile database ,Mobile search ,Mobile technology ,GSM services ,Telecommunications ,business ,computer - Abstract
The article introduces a model for the location of meaningful places for mobile telephone users, such as home and work anchor points, using passive mobile positioning data. Passive mobile positioning data is secondary data concerning the location of call activities or handovers in network cells that is automatically stored in the memory of service providers. This data source offers good potential for the monitoring of the geography and mobility of the population, since mobile phones are widespread, and similar standardized data can be used around the globe. We developed the model and tested it with 12 months' data collected by EMT, Estonia's largest mobile service provider, covering more than 0.5 million anonymous respondents. Modeling results were compared with population register data; this revealed that the developed model described the geography of the population relatively well, and can hence be used in geographical and urban studies. This approach also has potential for the development of location-b...
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- 2010
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30. Modelling Home and Work Locations of Populations Using Passive Mobile Positioning Data
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Siiri Silm, Rein Ahas, Erki Saluveer, and Olle Järv
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Data source ,education.field_of_study ,Database ,Work Locations ,Computer science ,business.industry ,Population ,Service provider ,computer.software_genre ,Work (electrical) ,Embedded system ,Location-based service ,business ,education ,Population Register ,computer ,Population geography - Abstract
The article introduces a model that uses passive mobile positioning data to determine respondents’ home and work anchor point locations. Passive mobile positioning data is secondary data concerning the location of call activities or hand-overs in network cells, which is automatically stored in the log files of service providers. This data source offers good potential for monitoring of the short-term mobility of populations, since mobile phones are widespread, and similar standardised data can be used around the globe. We developed the model and tested it with 12 months’ data collected by Estonia’s largest mobile service provider EMT, covering more than 0.5 million anonymous respondents. Modelling results were compared with population register data; this revealed that the developed model described the geography of the population relatively well, and can hence be used as a quantitative source in the study of population geography or for developing location-based services.
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- 2008
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- View/download PDF
31. Mobile positioning in sustainability studies: the social positioning method in studying commuter’s activity spaces in Tallinn
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M. Nuga, Ü. Mark, Rein Ahas, and Olle Järv
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Transport engineering ,Sustainable development ,Geography ,Data collection ,Sustainable city ,business.industry ,Urban planning ,Mobile phone ,Sustainability studies ,Global Positioning System ,business ,Boom - Abstract
This paper introduces the mobile phone positioning-based social positioning method (SPM) in studying activity spaces of commuters and residents of the city center of Tallinn. The SPM studies space-time behavior by analyzing the location coordinates of mobile phones and the social characteristics of the people carrying them. Our study experiments took place in the Tallinn and Tartu region in Estonia from 2003–2006. The results demonstrate that mobile positioning-based tracing is applicable in geographical studies, as an analysis of temporal movement patterns and activity spaces. This is good reference for analyzing travel diaries, especially for analyzing daily activity spaces and space consumption which is a key issue in sustainable planning of the sprawling cities. The biggest advantage of mobile positioning-based methods is that mobile phones are wide-spread, positioning works inside buildings, and the collection of movement data is done by a third party at regular intervals. The disadvantage of mobile positioning today is relatively low preciseness and surveillance fears. The boom in the generation of phones with A-GPS will raise positioning accuracy in the near future.
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- 2006
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32. Open data for accessibility and travel time analyses
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Henrikki Toivo Olavi Tenkanen, Vuokko Vilhelmiina Heikinheimo, Olle Järv, Maria Salonen, and Tuuli Kaarina Toivonen
33. Using Twitter data to evaluate tourism in Finland – A comparison with official statistics
- Author
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Håvard Wallin Aagesen, Anna Levlin, Sirpa Ojansuu, Alisa Redding, Petteri Muukkonen, Olle Järv, Muukkonen, Petteri, Department of Geosciences and Geography, Helsinki Institute of Sustainability Science (HELSUS), Earth Change Observation Laboratory (ECHOLAB), Digital Geography Lab, and Helsinki Institute of Urban and Regional Studies (Urbaria)
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1171 Geosciences ,Geography ,519 Social and economic geography ,education ,Maantiede ,geoinformatics ,geodata ,GIS - Abstract
Non
34. Automated social media content analysis from urban green areas – Case Helsinki
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Vuokko Heikinheimo, Henrikki Toivo Olavi Tenkanen, Tuomo Johannes Hiippala, Olle Järv, and Tuuli Kaarina Toivonen
35. Mobile positioning data
- Author
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Anu Masso, Siiri Silm, and Olle Järv
36. Yleistyvä monipaikkainen asuminen on huomioitava kriisinhallinnassa
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Elias Willberg, Olle Järv, Tuomas Väisänen, Tuuli Kaarina Toivonen, Geotieteiden ja maantieteen osasto, Kestävyystieteen instituutti (HELSUS), Digital Geography Lab, Kaupunkitutkimusinstituutti (Urbaria), and Doctoral Programme in Interdisciplinary Environmental Sciences
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1171 Geotieteet ,Geoinformatiikka
37. Matkapuhelinaineisto paljastaa kaupungin dynamiikan
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Claudia Bergroth, Olle Järv, Henrikki Toivo Olavi Tenkanen, and Tuuli Kaarina Toivonen
38. Kuidas mõista andmestunud maailma? Metodoloogiline teejuht
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Anu Masso, Katrin Tiidenberg, Andra Siibak, Anto Aasa, Mare Ainsaar, Mai Beilmann, Marju Himma, Indrek Ibrus, Olle Järv, Aleksei Kelli, Toomas Kirt, Mare Koit, Ragne Kõuts, Irene Kull, Andres Kuusik, Liisi Laineste, Liina Lindström, Innar Liiv, Jaan Masso, Kadri Muischnek, Maria Murumaa-Mengel, Kerli Müürisepp, Haldur Õim, Maarja Ojamaa, Hembo Pagi, Kristian Pentus, Maili Pilt, Pille Pruulmann-Vengerfeldt, Ave Roots, Leno Saarniit, Siiri Silm, Indrek Soidla, Marek Tamm, Kuldar Taveter, Kristel Uiboaed, Age Värv, Anna Veremchuk, and Triin Vihalemm
39. Virolaiset Suomessa – ylirajaisuus, monipaikkaisuus ja koronakriisi
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Olle Järv and Kerli Müürisepp
40. Exploratory visual methods to aggregate origin-destination geodata
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Eero Perola, Sara Todorovic, Petteri Muukkonen, Olle Järv, Muukkonen, Petteri, Helsinki Institute of Sustainability Science (HELSUS), Earth Change Observation Laboratory (ECHOLAB), Department of Geosciences and Geography, Digital Geography Lab, and Helsinki Institute of Urban and Regional Studies (Urbaria)
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1171 Geosciences ,Geography ,519 Social and economic geography ,education ,Maantiede ,geoinformatics ,geodata ,GIS - Abstract
Non
41. Saavutettavuuden analyysia todellisilla matka-ajoilla
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Maria Salonen, Tuuli Kaarina Toivonen, Henrikki Tenkanen, Vuokko Vilhelmiina Heikinheimo, and Olle Järv
42. Pako kaupungeista maalle?
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Willberg, Elias S., Olle Järv, Tuomas Väisänen, Tuuli Kaarina Toivonen, Geotieteiden ja maantieteen osasto, Digital Geography Lab, Kaupunkitutkimusinstituutti (Urbaria), and Kestävyystieteen instituutti (HELSUS)
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1171 Geotieteet
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