scholarly journals Anomalies of dwellers' collective geotagged behaviors in response to rainstorms: a case study of eight cities in China using smartphone location data

2019 ◽  
Vol 19 (10) ◽  
pp. 2169-2182
Author(s):  
Jiawei Yi ◽  
Yunyan Du ◽  
Fuyuan Liang ◽  
Tao Pei ◽  
Ting Ma ◽  
...  
Keyword(s):  
Time Series ◽  
Rainfall Intensity ◽  
Mainland China ◽  
Food Delivery ◽  
Location Based Services ◽  
Disaster Mitigation ◽  
Location Data ◽  
City Population ◽  
Emergency Events ◽  
The City

Abstract. Understanding city residents' collective geotagged behaviors (CGTBs) in response to hazards and emergency events is important in disaster mitigation and emergency response. It is a challenge, if not impossible, to directly observe CGTBs during a real-time matter. This study used the number of location requests (NLR) data generated by smartphone users for a variety of purposes such as map navigation, car hailing, and food delivery to infer the dynamics of CGTBs in response to rainstorms in eight Chinese cities. We examined rainstorms, flooding, and NLR anomalies, as well as the associations among them, in eight selected cities across mainland China. The time series NLR clearly reflects cities' general diurnal rhythm, and the total NLR is moderately correlated with the total city population. Anomalies of the NLR were identified at both the city and grid scale using the Seasonal Hybrid Extreme Studentized Deviate (S-H-ESD) method. Analysis results demonstrated that the NLR anomalies at the city and grid levels are well associated with rainstorms, indicating that city residents request more location-based services (e.g., map navigation, car hailing, food delivery, etc.) when there is a rainstorm. However, the sensitivity of the city residents' collective geotagged behaviors in response to rainstorms varies in different cities as shown by different peak rainfall intensity thresholds. Significant high peak rainfall intensity tends to trigger city flooding, which leads to increased location-based requests as shown by positive anomalies in the time series NLR.

scholarly journals Urban anomalies in response to rainstorms based on smartphone location data: a case study of eight cities in China

2019 ◽  
Author(s):  
Jiawei Yi ◽  
Yunyan Du ◽  
Fuyuan Liang ◽  
Tao Pei ◽  
Ting Ma ◽  
...  
Keyword(s):  
Time Series ◽  
Rainfall Intensity ◽  
Mainland China ◽  
Food Delivery ◽  
Location Based Services ◽  
Location Data ◽  
City Population ◽  
The City ◽  
Method Analysis

Abstract. This study explored city residents’ collective geo-tagged behaviors in response to rainstorms using the number of location request (NLR) data generated by smartphone users. We examined the rainstorms, flooding, NLR anomalies, as well as the associations among them in eight selected cities across the mainland China. The time series NLR clearly reflects cities’ general diurnal rhythm and the total NLR is moderately correlated with the total city population. Anomalies of NLR were identified at both the city and grid scale using the S-H-ESD method. Analysis results manifested that the NLR anomalies at the city and grid levels are well associated with rainstorms, indicating city residents request more location-based services (e.g. map navigation, car hailing, food delivery, etc.) when there is a rainstorm. However, sensitivity of the city residents’ collective geo-tagged behaviors in response to rainstorms varies in different cities as shown by different peak rainfall intensity thresholds. Significant high peak rainfall intensity tends to trigger city flooding, which lead to increased location-based requests as shown by positive anomalies on the time series NLR.

scholarly journals Identifying resting locations of a small elusive forest carnivore using a two-stage model accounting for GPS measurement error and hidden behavioral states

2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Dalton J. Hance ◽  
Katie M. Moriarty ◽  
Bruce A. Hollen ◽  
Russell W. Perry
Keyword(s):  
Time Series ◽  
Measurement Error ◽  
Gaussian State ◽  
Parameter Estimates ◽  
Accelerometer Data ◽  
Two Stage ◽  
Location Data ◽  
Gps Measurement ◽  
Activity Measurements ◽  
Behavioral States

Abstract Background Studies of animal movement using location data are often faced with two challenges. First, time series of animal locations are likely to arise from multiple behavioral states (e.g., directed movement, resting) that cannot be observed directly. Second, location data can be affected by measurement error, including failed location fixes. Simultaneously addressing both problems in a single statistical model is analytically and computationally challenging. To both separate behavioral states and account for measurement error, we used a two-stage modeling approach to identify resting locations of fishers (Pekania pennanti) based on GPS and accelerometer data. Methods We developed a two-stage modelling approach to estimate when and where GPS-collared fishers were resting for 21 separate collar deployments on 9 individuals in southern Oregon. For each deployment, we first fit independent hidden Markov models (HMMs) to the time series of accelerometer-derived activity measurements and apparent step lengths to identify periods of movement and resting. Treating the state assignments as given, we next fit a set of linear Gaussian state space models (SSMs) to estimate the location of each resting event. Results Parameter estimates were similar across collar deployments. The HMMs successfully identified periods of resting and movement with posterior state assignment probabilities greater than 0.95 for 97% of all observations. On average, fishers were in the resting state 63% of the time. Rest events averaged 5 h (4.3 SD) and occurred most often at night. The SSMs allowed us to estimate the 95% credible ellipses with a median area of 0.12 ha for 3772 unique rest events. We identified 1176 geographically distinct rest locations; 13% of locations were used on > 1 occasion and 5% were used by > 1 fisher. Females and males traveled an average of 6.7 (3.5 SD) and 7.7 (6.8 SD) km/day, respectively. Conclusions We demonstrated that if auxiliary data are available (e.g., accelerometer data), a two-stage approach can successfully resolve both problems of latent behavioral states and GPS measurement error. Our relatively simple two-stage method is repeatable, computationally efficient, and yields directly interpretable estimates of resting site locations that can be used to guide conservation decisions.

scholarly journals Exploring Impact of Surrounding Service Facilities on Urban Vibrancy Using Tencent Location-Aware Data: A Case of Guangzhou

2021 ◽  
Vol 13 (2) ◽  
pp. 444
Author(s):  
Xucai Zhang ◽  
Yeran Sun ◽  
Ting On Chan ◽  
Ying Huang ◽  
Anyao Zheng ◽  
...  
Keyword(s):  
Rapid Development ◽  
Ordinary Least Squares ◽  
Information And Communications Technology ◽  
Time Data ◽  
Location Data ◽  
Point Of Interest ◽  
Quality Life ◽  
City Construction ◽  
The Impact ◽  
The City

Urban vibrancy contributes towards a successful city and high-quality life for people as one of its vital elements. Therefore, the association between service facilities and vibrancy is crucial for urban managers to understand and improve city construction. Moreover, the rapid development of information and communications technology (ICT) allows researchers to easily and quickly collect a large volume of real-time data generated by people in daily life. In this study, against the background of emerging multi-source big data, we utilized Tencent location data as a proxy for 24-h vibrancy and adopted point-of-interest (POI) data to represent service facilities. An analysis framework integrated with ordinary least squares (OLS) and geographically and temporally weighted regression (GTWR) models is proposed to explore the spatiotemporal relationships between urban vibrancy and POI-based variables. Empirical results show that (1) spatiotemporal variations exist in the impact of service facilities on urban vibrancy across Guangzhou, China; and (2) GTWR models exhibit a higher degree of explanatory capacity on vibrancy than the OLS models. In addition, our results can assist urban planners to understand spatiotemporal patterns of urban vibrancy in a refined resolution, and to optimize the resource allocation and functional configuration of the city.

scholarly journals Privacy vs. Reward in Indoor Location-Based Services

2016 ◽  
Vol 2016 (4) ◽  
pp. 102-122 ◽  
Author(s):  
Kassem Fawaz ◽  
Kyu-Han Kim ◽  
Kang G. Shin
Keyword(s):  
Location Privacy ◽  
Indoor Localization ◽  
Service Providers ◽  
Location Based Services ◽  
Location Information ◽  
Privacy Concerns ◽  
Indoor Location ◽  
Location Data ◽  
Personalized Services ◽  
Privacy Risks

AbstractWith the advance of indoor localization technology, indoor location-based services (ILBS) are gaining popularity. They, however, accompany privacy concerns. ILBS providers track the users’ mobility to learn more about their behavior, and then provide them with improved and personalized services. Our survey of 200 individuals highlighted their concerns about this tracking for potential leakage of their personal/private traits, but also showed their willingness to accept reduced tracking for improved service. In this paper, we propose PR-LBS (Privacy vs. Reward for Location-Based Service), a system that addresses these seemingly conflicting requirements by balancing the users’ privacy concerns and the benefits of sharing location information in indoor location tracking environments. PR-LBS relies on a novel location-privacy criterion to quantify the privacy risks pertaining to sharing indoor location information. It also employs a repeated play model to ensure that the received service is proportionate to the privacy risk. We implement and evaluate PR-LBS extensively with various real-world user mobility traces. Results show that PR-LBS has low overhead, protects the users’ privacy, and makes a good tradeoff between the quality of service for the users and the utility of shared location data for service providers.

Visual Arts, Representations and Interventions in Contemporary China

2018 ◽  
Keyword(s):  
Urban Space ◽  
Visual Arts ◽  
Cultural Production ◽  
Mainland China ◽  
Social Changes ◽  
Power Structures ◽  
Cultural Activism ◽  
Political Issues ◽  
Wide Range ◽  
The City

This edited volume provides a multifaceted investigation of the dynamic interrelations between visual arts and urbanization in contemporary Mainland China with a focus on unseen representations and urban interventions brought about by the transformations of the urban space and the various problems associated with it. Through a wide range of illuminating case studies, the authors demonstrate how innovative artistic and creative practices initiated by various stakeholders not only raise critical awareness on socio-political issues of Chinese urbanization but also actively reshape the urban living spaces. The formation of new collaborations, agencies, aesthetics and cultural production sites facilitate diverse forms of cultural activism as they challenge the dominant ways of interpreting social changes and encourage civic participation in the production of alternative meanings in and of the city. Their significance lies in their potential to question current values and power structures as well as to foster new subjectivities for disparate individuals and social groups.

RESTRUCTURING IN RESIDENTIAL AREAS AND TRANSFORMATION OF THE URBAN SPACE OF THE METROPOLIS

2021 ◽  
Vol 93 (1) ◽  
pp. 134-139
Author(s):  
A.A. STEPANENKO ◽  
Keyword(s):  
Economic Growth ◽  
Urban Space ◽  
Building Materials ◽  
Recycling Rate ◽  
Residential Areas ◽  
Construction Waste ◽  
Cycle Economy ◽  
City Population ◽  
Favorable Conditions ◽  
The City

The article considers the developed model of the closed-cycle economy, which, along with economic parameters, takes into account pollution and consumption of building materials suitable for recycling. The model reflects the idea that the economic growth of a society alone cannot maintain or improve the existing quality of the environment, and for this it is necessary to increase the recycling rate. The purpose of the study is to reveal the factors influencing the increase in the level of recycling when introducing efficient and environmentally friendly systems for managing construction waste in megacities. The results of the study will affect the improvement of the quality and standards of life of the city population, the creation of favorable conditions for a safe, healthy and the prosperous life of people while ensuring the economic growth of the city. The process of the managing the growing volume of construction waste is reflected, recycling is emphasized.

scholarly journals Urban influence on the concentration and composition of submicron particulate matter in central Amazonia

2018 ◽  
Author(s):  
Suzane S. de Sá ◽  
Brett B. Palm ◽  
Pedro Campuzano-Jost ◽  
Douglas A. Day ◽  
Weiwei Hu ◽  
...  
Keyword(s):  
Time Series ◽  
Particulate Matter ◽  
Air Quality ◽  
Nitrogen Oxides ◽  
Mass Concentration ◽  
Critical Role ◽  
Metropolitan Region ◽  
Anthropogenic Emissions ◽  
Organic Mass ◽  
The City

Abstract. Fundamental to quantifying the influence of human activities on climate and air quality is an understanding of how anthropogenic emissions affect the concentrations and composition of airborne particulate matter (PM). The central Amazon basin, especially around the city of Manaus, Brazil, has experienced rapid changes in the past decades due to ongoing urbanization. Herein, changes in the concentration and composition of submicron PM due to pollution downwind of the Manaus metropolitan region are reported as part of the GoAmazon2014/5 experiment. A high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a suite of other gas- and particle-phase instruments were deployed at the T3 research site, 70 km downwind of Manaus, during the wet season. At this site, organic components represented on average 79 ± 7 % of the non-refractory PM1 mass concentration, which was in the same range as several upwind sites. The organic PM1 was, however, considerably more oxidized at T3 compared to upwind measurements. Positive-matrix factorization (PMF) was applied to the time series of organic mass spectra collected at the T3 site, yielding three factors representing secondary processes (73 ± 15 % of total organic mass concentration) and three factors representing primary anthropogenic emissions (27 ± 15 %). Fuzzy c-means clustering (FCM) was applied to the afternoon time series of concentrations of NOy, ozone, total particle number, black carbon, and sulfate. Four clusters were identified and characterized by distinct airmass origins and particle compositions. Two clusters, Bkgd-1 and Bkgd-2, were associated with background conditions. Bkgd-1 appeared to represent near-field atmospheric PM production and oxidation of a day or less. Bkgd-2 appeared to represent material transported and oxidized for two or more days, often with out-of-basin contributions. Two other clusters, Pol-1 and Pol-2, represented the Manaus influence, one apparently associated with the northern region of Manaus and the other with the southern region of the city. A composite of the PMF and FCM analyses provided insights into the anthropogenic effects on PM concentration and composition. The increase in mass concentration of submicron PM ranged from 25 % to 200 % under polluted compared to background conditions, including contributions from both primary and secondary PM. Furthermore, a comparison of PMF factor loadings for different clusters suggested a shift in the pathways of PM production under polluted conditions. Nitrogen oxides may have played a critical role in these shifts. Increased concentrations of nitrogen oxides can shift pathways of PM production from HO2-dominant to NO-dominant as well as increase the concentrations of oxidants in the atmosphere. Consequently, the oxidation of biogenic and anthropogenic precursor gases as well as the oxidative processing of pre-existing atmospheric PM can be accelerated. The combined set of results demonstrates the susceptibility of atmospheric chemistry, air quality, and associated climate forcing to anthropogenic perturbations over tropical forests.

scholarly journals Complying with Privacy Legislation: From Legal Text to Implementation of Privacy-Aware Location-Based Services

2018 ◽  
Vol 7 (11) ◽  
pp. 442 ◽  
Author(s):  
Mehrnaz Ataei ◽  
Auriol Degbelo ◽  
Christian Kray ◽  
Vitor Santos
Keyword(s):  
Data Privacy ◽  
Location Privacy ◽  
Service Providers ◽  
Location Based Services ◽  
Legal Text ◽  
General Data Protection Regulation ◽  
Location Data ◽  
Privacy Laws ◽  
Technical Issues ◽  
General Data

An individual’s location data is very sensitive geoinformation. While its disclosure is necessary, e.g., to provide location-based services (LBS), it also facilitates deep insights into the lives of LBS users as well as various attacks on these users. Location privacy threats can be mitigated through privacy regulations such as the General Data Protection Regulation (GDPR), which was introduced recently and harmonises data privacy laws across Europe. While the GDPR is meant to protect users’ privacy, the main problem is that it does not provide explicit guidelines for designers and developers about how to build systems that comply with it. In order to bridge this gap, we systematically analysed the legal text, carried out expert interviews, and ran a nine-week-long take-home study with four developers. We particularly focused on user-facing issues, as these have received little attention compared to technical issues. Our main contributions are a list of aspects from the legal text of the GDPR that can be tackled at the user interface level and a set of guidelines on how to realise this. Our results can help service providers, designers and developers of applications dealing with location information from human users to comply with the GDPR.

scholarly journals Earthquake Resistant Residential Neighborhood in China: Examination of vulnerability in outdoor spaces

2018 ◽  
Vol 3 (7) ◽  
pp. 59-69
Author(s):  
Xue Ma ◽  
Ryuzo Ohno
Keyword(s):  
Publishing House ◽  
Disaster Mitigation ◽  
Target Area ◽  
Earthquake Disaster ◽  
Residential Neighborhood ◽  
Outdoor Spaces ◽  
Earthquake Resistant ◽  
International Publishing ◽  
The City ◽  
Open Access Article

China is a seismic active country. We suffered a large number of fatalities by earthquake damage. A great deal of requirements on disaster mitigation has been putting forward and which is becoming a hot topic in the society. This paper focuses on the safety situation of residential environment in Chinese cities, tries to examine the vulnerabilities for earthquake disaster mitigation. We chose the city of Tianjin as target area applying for the detail analysis. An evaluation was interpreted into suggestions and advices on planning and management. Keywords: Vulnerability, Earthquake disaster mitigation, Residential area eISSN 2514-751X © 2018. The Authors. Published for AMER ABRA cE-Bs by e-International Publishing House, Ltd., UK. This is an open-access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). Peer–review under responsibility of AMER (Association of Malaysian Environment-Behaviour Researchers), ABRA (Association of Behavioural Researchers on Asians) and cE-Bs (Centre for Environment-Behaviour Studies), Faculty of Architecture, Planning & Surveying, Universiti Teknologi MARA, Malaysia.

scholarly journals Determinants of SARS-CoV-2 transmission to guide vaccination strategy in a city

2020 ◽  
Author(s):  
Sarah C. Brüningk ◽  
Juliane Klatt ◽  
Madlen Stange ◽  
Alfredo Mari ◽  
Myrta Brunner ◽  
...  
Keyword(s):  
Vaccination Strategy ◽  
Population Level ◽  
Data Sets ◽  
Epidemic Dynamics ◽  
Modelling Analysis ◽  
City Population ◽  
Senior Population ◽  
Spatio Temporal ◽  
Socioeconomic Data ◽  
The City

Transmission chains within cities provide an important contribution to case burden and economic impact during the ongoing COVID-19 pandemic, and should be a major focus for preventive measures to achieve containment. Here, at very high spatio-temporal resolution, we analysed determinants of SARS-CoV-2 transmission in a medium-sized European city. We combined detailed epidemiological, mobility, and socioeconomic data-sets with whole genome sequencing during the first SARS-CoV-2 wave. Both phylogenetic clustering and compartmental modelling analysis were performed based on the dominating viral variant (B.1-C15324T; 60% of all cases). Here we show that transmissions on the city population level are driven by the socioeconomically weaker and highly mobile groups. Simulated vaccination scenarios showed that vaccination of a third of the population at 90% efficacy prioritising the latter groups would induce a stronger preventive effect compared to vaccinating exclusively senior population groups first. Our analysis accounts for both social interaction and mobility on the basis of molecularly related cases, thereby providing high confidence estimates of the underlying epidemic dynamics that may readily be translatable to other municipal areas.

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