Mobile Phone Signal Research Articles

Facilitators and barriers to uptake of digital adherence technologies in improving TB care in Ethiopia: A qualitative study.

The role of digital adherence technologies (DATs) in improving tuberculosis (TB) treatment adherence is an emerging area of policy discussion. Given that the directly observed therapy (DOT) has several shortcomings, alternative approaches such as DATs are vital to enhancing current practices by rendering person-centered models to support the completion of TB treatments. However, there is a lack of evidence that informs policy and program on facilitators and barriers to the uptake of DATs in the context of country-specific real-world situations. The purpose of this study was to explore the facilitators and barriers to the uptake of DATs by drawing from the accounts of people with TB (PWTB), healthcare workers (HCWs) and other key policy stakeholders in Ethiopia. A qualitative study was conducted to capture the perspectives of participants to help understand the contextual factors that are important in the uptake of DATs. The overall response from participants highlighted that uptake of DATs was high despite some critical implementation barriers. DATs were useful in reducing the burden of treatment management on both PWTB and HCWs, improving adherence and flexibility, and enhancing the patient-provider relationship. The relative simplicity of using DATs, positive feedback from important others, and current policy opportunities were seen as additional facilitators for the uptake of DATs in the Ethiopian context. Key barriers including network issues (mobile phone signals), lack of inclusivity and fear of stigma (as perceived by HCWs) were identified as key barriers that could limit the implementation of DATs. The findings of this qualitative study have provided a rich set of perspectives relevant to policymakers, providers and implementers in identifying the facilitators and barriers to the uptake of DATs in Ethiopia. The overall finding suggests that DATs are highly acceptable among the diverse categories of participants in the presence of critical barriers that limit uptake of DATs including poor infrastructure. However, key policy stakeholders believe that there are several opportunities and initiatives for feasible implementation, adaptation and scale-up of DATs in the current Ethiopian context.

Reexamining exposure from truck emissions considering daily movement of individuals

With the growing demand for urban freight transportation, trucks emit a large amount of pollutants such as particulate matters and nitrogen oxides, increasingly affecting public health. This study establishes a modelized air dispersion structure to simulate pollutant concentration distribution. By integrating multiple data sources including mobile phone signals and satellite images, we reconstruct the daily trajectories of individuals and further incorporate simulated pollution concentrations in calculating dynamic and static exposure of individuals to truck emissions. Econometric models considering spatial dependence are developed to evaluate the influencing factors and elucidate the mechanisms of pollutant exposure. Results show factors including freight demand, road network, residential and employment locations, personal commuting distance, and population age structure matter in assessing truck emission exposure. As a result, a mixture of vehicular emission standards, urban traffic control, land planning, and industrial policies is proposed to reduce truck pollutant exposure and safeguard public health.

Enhanced electromagnetic wave absorption in ultrathin cement-based composites with integrated multi-dimensional carbon materials

The challenges posed by electromagnetic waves (EMW) cause significant interference in electronic device operation, jeopardizing information security and disturbing normal biological functions, which necessitate attention. Multi-scale carbon/cement-based composites were developed for EMW absorption by integrating multi-dimensional carbon materials, including carbon nanotubes (1D), graphene (2D), and modified carbon microspheres (3D). These composites demonstrate exceptional EMW absorption capabilities, with a minimum reflection loss (RLmin) of −44.32 dB and an effective absorption bandwidth (EAB) of 3.644 GHz at X band, merely having a thickness of 1.90 mm. Furthermore, the superior EMW absorption properties of these composites are confirmed through radar cross-section (RCS) simulation and electric field distribution analysis. A small house is constructed of designed three-layer multi-scale carbon/cement-based composites in which the actual EMW reflection losses are less than –10 dB within the whole test frequency range, and these composites can effectively obstruct 5 G mobile phone signals. Therefore, multi-scale carbon/cement-based composites could be promising candidates for effectively solving the increasingly serious problem of electromagnetic radiation pollution.

Confronting mobile phone signal coverage and helicopter emergency medical service travel time: A geospatial analysis in the northwest macro-region of Paraná State, Brazil

Objective The aim of this study was to conduct a detailed geospatial analysis of mobile phone signal coverage in the northwest macro-region of Paraná State, Brazil, seeking to identify areas where limitations in coverage may be related to lengthy travel times of the helicopter emergency medical service (HEMS) for the assistance of victims of road traffic injuries (RTIs). Methods An observational study was conducted to examine mobile phone signal coverage and HEMS travel times from 2017 to 2021. HEMS travel times were categorized into four groups: T1 (0–15 min), T2 (16–30 min), T3 (31–45 min), and T4 (over 45 min). Empirical Bayesian Kriging was used to map areas with low mobile signal coverage. The Kruskal–Wallis test and Dwass–Steel–Critchlow–Fligner comparative analyses were performed to explore how mobile signal coverage relates to HEMS travel times to RTI locations. Results There were 470 occurrences of RTIs attended by HEMS, of which 108 (23%) resulted in on-site fatalities. Among these deaths, 47 (26.85%) occurred in areas with low mobile phone signal coverage (“shadow areas”). Low mobile phone signal coverage identified at 175 (37.24%) RTIs locations, was unevenly distributed across the macro-region. The lowest medians of mobile signal quality were predominantly found in areas with HEMS travel times exceeding 30 min, corresponding to signal strength values of −98.44 (T3) and −100.75 (T4) dBm. This scenario represents a challenge for effective communication to activate HEMS. In the multiple comparison analysis among travel time groups, significant differences were observed between T1 and T2 (p < 0.001), T1 and T3 (p < 0.001), T1 and T4 (p < 0.001), and T2 and T3 (p < 0.001), indicating a potential association between lower mobile phone signal coverage and longer HEMS travel times. Conclusion It can be concluded that poor mobile phone signals in remote areas can hinder HEMS activation, potentially delaying the start of treatment for RTIs. Identification of the shadow areas can help communication and health managers in designing and implementing the necessary changes to improve mobile phone signal coverage and consequently reduce delays in the initial response to RTIs.

The impact of non-local human capital on local wages: exploring daily inflow of non-local human capital and its impact on local wages

ABSTRACT This study investigates the impact of daily inflow of non-local human capital on the wages of locals by tracing 14 billion inter-borough movements of people in Seoul, South Korea, in 2019, using mobile phone signal data as a proxy for the location of individuals. The findings reveal that the daily inflow of non-local human capital is beneficial for the wages of low-educated locals but detrimental for the wages of highly-educated locals. Additionally, the study finds that the inflow is advantageous for locals only when it originates from different age groups, and it is more beneficial when it comes from the older age group than from the younger age group. This research advances the existing literature on the relationship between local human capital and local wages by highlighting the substantial daily inflow of non-local human capital and demonstrating the significance of not only local but also non-local human capital in local wages.

Informing Urban Flood Risk Adaptation by Integrating Human Mobility Big Data During Heavy Precipitation.

Understanding the impact of heavy precipitation on human mobility is critical for finer-scale urban flood risk assessment and achieving sustainable development goals #11 to build resilient and safe cities. Using ∼2.6 million mobile phone signal data collected during the summer of 2018 in Jiangsu, China, this study proposes a novel framework to assess human mobility changes during rainfall events at a high spatial granularity (500 m grid cell). The fine-scale mobility map identifies spatial hotspots with abnormal clustering or reduced human activities. When aggregating to the prefecture-city level, results show that human mobility changes range between -3.6 and 8.9%, revealing varied intracity movement across cities. Piecewise structural equation modeling analysis further suggests that city size, transport system, and crowding level directly affect mobility responses, whereas economic conditions influence mobility through multiple indirect pathways. When overlaying a historical urban flood map, we find such human mobility changes help 23 cities reduce 2.6% flood risks covering 0.45 million people but increase a mean of 1.64% flood risks in 12 cities covering 0.21 million people. The findings help deepen our understanding of the mobility pattern of urban dwellers after heavy precipitation events and foster urban adaptation by supporting more efficient small-scale hazard management.

Effects of built environment on metro ridership at a microscopic scale: a case study of Xi’an, China

ABSTRACT Few studies have examined the relationship at the microscopic spatial scale. In this study, multiple sources of data including mobile phone signal data, automatic fare collection system data, geo-information data, and street-view image data are combined to measure metro ridership and built environment at the plot or block scale. The Random Gradient Boosting Decision Tree was used to explore relationship between the built environment and ridership. The results show the following: (1) the relationship between built environment and ridership shows different types of curves. (2) The path distance to the metro station and the visual perception of road space have more significant impacts on ridership than road network density. (3) The location of the grid also affects grid-level metro ridership. The results suggest that planners should consider the locational factors, pay attention to the different effective thresholds of different variables on ridership and the longitudinal landscaping of non-motorized urban roads.

A street-point method to measure the spatiotemporal relationship between walkability and pedestrian flow

Walkability indicators are a pivotal method to evaluate the role of the built environment in peoples' decisions regarding active mobility, supporting the application of public measures that contribute to more sustainable and resilient regions. Currently, data used to evaluate associations between walkability indicators and travel behavior is obtained via traditional methods of data collection, like questionnaires, that are costly and hard to scale in large urban environments. Moreover, the spatial resolution of most indicators may not be sufficient to support granular local public interventions. To face these issues, we propose a novel walkability indicator that provides a score of walkability for every one-meter street point, based on street conditions and accessibility to points of interest calculated with a Cumulative-Gaussian impedance function. Resorting to Linear and Geospatial Weighted Regressions, we evaluate the associations between walkability features and pedestrian flow data retrieved from mobile phone communication signals for a week in March 2022. The relationship between walkability features and pedestrian flow is stronger during workdays, in which accessibility to education, food amenities and government services are the most important predictors. On the weekend, the features with more explanatory power are accessibility to crosswalks and leisure amenities. Accessibility to public transport, sidewalk width and slope seem to impact pedestrian decisions independently of the day type, although the impact is stronger on weekends. This study provides policy makers and urban planners with a practical tool to effectively support the evaluation of current street conditions and access areas that are underserved, as well as plan and gauge new local interventions, while objectively understanding their impacts on pedestrian mobility.

The Spatial Association between Residents’ Leisure Activities and Tourism Activities Using Colocation Pattern Measures: A Case Study of Nanjing, China

With the increasing trend of residents and tourists sharing urban spaces, the boundary between leisure spaces and tourism spaces is gradually being blurred. However, few studies have quantified the spatiotemporal correlation patterns of residents’ leisure activities and tourists’ activities. To fill this gap, this paper takes Nanjing as an example to study the temporal and spatial correlation between residents’ leisure activities and tourists’ activities based on mobile phone signal data. First, through kernel density analysis, it is found that there is a spatial overlap between residents’ leisure activities and tourists’ activities. Then, the spatial and temporal correlation patterns of residents’ leisure activities and tourists’ activities are analyzed through the colocation quotient. According to our findings, (1) residents’ leisure activities and tourists’ activities are not spatially correlated, indicating that they are relatively independent in space both during the week and on weekends. (2) On weekday afternoons, the spatial correlation between residents’ and tourists’ leisure activities is strongest. On weekends, the night is when residents’ leisure activities and tourists’ activities are most closely related. (3) The correlation area is mainly distributed in areas near famous scenic spots, as well as public spaces such as parks and squares. Based on the above analysis, this paper aims to study the resident-tourist interaction in the spatial context to provide directions for improving the attractiveness of cities, urban transportation, services, and marketing strategies.

Mobile phone coverage and infant mortality in sub-Saharan Africa

Infant mortality is still high in Sub-Saharan Africa. Mobile phone technology has the potential to reduce mortality by facilitating the exchange of information. To test for effects, we combine georeferenced information on mobile phone signal coverage with infant mortality data on 1,268,041 children born in 30 Sub-Saharan African countries between 1999–2016. Our results reveal that infant mortality risk drops substantially as mobile phone coverage expands. Infants are 0.9 percentage points less likely to die within the first year after birth compared to their sibling(s) when mobile phone signal is available. In line with this result, we also find that fertility rates decline with the rollout of mobile coverage. Suggestive evidence indicates that improved health knowledge is relevant in explaining our findings. Mobile-phone related changes in access to in-person healthcare services or improvements in income opportunities, on the other hand, are unlikely to play an important role.

Household Economic Welfare During the Rise of Mobile Phone Expansion in Indonesia

The proliferation of mobile phones in developing countries has significant implications for those countries. Although numerous studies have examined the various advantages of mobile phone use, the relationship between mobile phone access and the economic welfare of households has received comparatively little attention. This paper examines the effects of mobile phone on household expenditures in 2007 and 2014 utilising the Indonesian Family Life Survey (IFLS) combined with Potential Village Survey (PODES). Ordinary Least Square (OLS), Endogenous Treatment Regression (ETR), quantile regression, and two-way fixed effect estimations are used to identify the homogeneous and heterogeneous effects of mobile phone use. According to the estimated results, mobile phone access and signal quality significantly increases household expenditure. According to the results of quantile regression, mobile phone access has the greatest effect on the upper expenditure distributions. It is highlighting the importance of promoting a policy that increases mobile phone and the supporting infrastructure on the lower expenditure distributions.

Reducing societal impacts of SARS-CoV-2 interventions through subnational implementation.

To curb the initial spread of SARS-CoV-2, many countries relied on nation-wide implementation of non-pharmaceutical intervention measures, resulting in substantial socio-economic impacts. Potentially, subnational implementations might have had less of a societal impact, but comparable epidemiological impact. Here, using the first COVID-19 wave in the Netherlands as a case in point, we address this issue by developing a high-resolution analysis framework that uses a demographically stratified population and a spatially explicit, dynamic, individual contact-pattern based epidemiology, calibrated to hospital admissions data and mobility trends extracted from mobile phone signals and Google. We demonstrate how a subnational approach could achieve similar level of epidemiological control in terms of hospital admissions, while some parts of the country could stay open for a longer period. Our framework is exportable to other countries and settings, and may be used to develop policies on subnational approach as a better strategic choice for controlling future epidemics.

Understanding spatial-temporal travel demand of private and shared e-bikes as a feeder mode of metro stations

Private e-bikes and shared e-bikes are gradually becoming the preferred modes of feeders for a vast number of metro passengers in China, opening up new potential for sustainable urban transportation development. This study proposes a method to identify feeder behaviors from private and shared e-bikes to the metro using mobile phone signal data and shared e-bike operation order data in Nanning, China. Then, the Light Gradient Boosting Machine models are constructed to reveal the influence of various factors on the feeder demand for two kinds of e-bikes in metro stations, to promote integrated travel of e-bikes to the metro. The results show that the demand for private e-bikes in metro stations is significantly higher than that of shared e-bikes, and the demand for the two types of feeder modes during the morning and evening peak hours on weekdays is greater than that in other periods. Secondly, the density of educational facilities has a positive effect on the demand for both feeder modes, and it has a greater impact on the demand for private e-bikes. Thirdly, the distance to the city center has a non-linear effect on the demand for private e-bikes. The farther away from the city center, the more feeders use private e-bikes to travel, and the fewer feeders use shared e-bikes. These findings can help planners better understand how various factors influence feeder demand.

Does the mobile phone affect social development? Evidence from Indonesian villages

This paper analyses the impact of Information and Communication Technology (ICT) on social development in Indonesian Villages. In this study, I use data from different waves of the Indonesian Village Potential Statistics (Potensi Desa) to determine whether mobile phone signal strength affects social development indicators. The results indicate that villages with a strong signal are statistically more likely to possess the proper infrastructure programs. Furthermore, mobile phones increase the availability of village libraries and access to credit for small and medium enterprises (SMEs). Using the plausibly exogenous variation of lightning strike intensity as the instrumental variable, this study suggests that higher mobile phone signal strength is positively associated with the policies implemented by the village head and leads to better social development. As the mechanisms, this study shows that mobile phones increase the likelihood of having collective action and civic engagement, increasing villagers’ political participation and use of telecommunication services, thus leading to an increase in village government’s accountability.

Time-varying and non-linear associations between metro ridership and the built environment

The metro is the backbone of the transport system in many cities. Analyzing the built-environment correlates of metro ridership is crucial for transit-oriented development (TOD) planning and practice. Although numerous studies went along this line, they have rarely considered the non-linearity and temporal heterogeneity in the association of metro ridership with the built environment. After collecting transit smart card data, geo-data, and mobile phone signal data, this study adopts the random forest model to reveal the complex association of hourly metro ridership in November 2019 in Chengdu (China) with the built environment in three times of day (i.e., morning peak, noon off-peak, and evening peak hours). Notably, the contribution of several variables, such as the number of station entrances/overpasses and parking density, has rarely been considered in the literature. The results confirm the presence of non-linearity and temporal heterogeneity in the aforementioned association. Access to the city center and population density are strong predictors of metro ridership in the morning peak hour, whereas employment density, enterprise density, and road density are strong predictors in the evening peak hour. There are great differences in the correlates of metro ridership in different periods. Critical TOD planning parameters are also identified from the partial dependence plots obtained from random forest modeling.

Are human activities consistent with planning? A big data evaluation of master plan implementation in Changchun

Urban planning has a significant impact on human spatial activities. The evaluation of urban planning implementation is important to determine how urban planning can guide spatial activities. However, existing evaluation methods focus more on physical space and largely neglect the object of urban planning—the people themselves. Furthermore, they rarely evaluate whether urban construction truly meets people’s demands. This study analyzes the spatial pattern of employment in Changchun, China, based on data on human activities and compares it with the Changchun Master Plan. Spatial patterns and the structure of employment in Changchun were calculated using mobile phone signal data, and the implementation effect of employment space in the master plan was evaluated using human activity patterns. The results demonstrate that although urban planning plays a role in guiding residents’ employment activities, it cannot achieve the plan’s desired effect. Many construction lands do not play an effective role in guiding residents’ spatial behavior based on the master plan. Moreover, the commuting distance in suburban areas is much longer than that in central areas. This phenomenon is not caused by the plan’s multicenter structure but by the lagging of the urban development behind planning expectations and delays in planning revision. This study indicates that urban planning evaluation is important after implementation and big data are a significant tool as they can precisely assess whether the plan has achieved its goals.

A GloVe Model for Urban Functional Area Identification Considering Nonlinear Spatial Relationships between Points of Interest

As cities continue to grow, the functions of urban areas change and problems arise from previously constructed urban planning schemes. Hence, the actual distribution of urban functional areas needs to be confirmed. POI data, as a representation of urban facilities, can be used to mine the spatial correlation within the city. Therefore it has been widely used for urban functional area extraction. Previous studies are mostly devoted to mining POI linear location relationships and do not comprehensively mine POI spatial information, such as spatial interaction information. This results in less accurate modeling of the relationship between POI-based and urban function types. In addition, they all use Euclidean distance for proximity assessment, which is not realistic. This paper proposes an urban functional area identification method that considers the nonlinear spatial relationship between POIs. First, POI adjacency is determined according to road network constraints, which forms the basis of a co-occurrence matrix. Then, a Global Vectors (GloVe) model is used to train POI category vectors and the feature vectors for each basic research unit are obtained using weighted averages. This is followed by clustering analysis, which is realized by a K-Means++ algorithm. Lastly, the functional areas are labeled according to the POI category ratio, enrichment factors, and mobile phone signal heat data. The model was tested experimentally, using core areas of Zhengzhou City in China as an example. When the results were compared with a Baidu map, we confirmed that making full use of nonlinear spatial relationships between POIs delivers high levels of identification accuracy for urban functional areas.

Design and Implementation of Groundwater Monitor Based on GPRS Transmitted

In practical applications, the geological environmental monitoring instruments should have more stringent instrument properties, their resistance to high and low temperature, sealing, corrosion resistance and low power consumption, They are all have higher requirements. While the areas whitout public network coverage are mostly alpine high - altitude areas, the instruments are exposed to relatively harsh geological conditions for a long time. The timely and stable data communication transmission technology is the key technology to ensure stable operation of groundwater dynamic monitoring systems. At present, GSM short message format is mostly used in the groundwater dynamic remote monitoring technology, but this approach is extremely limited in field applications. For obtaining groundwater monitoring parameters not affected by the limitation of public wireless network coverage area, the GPRS satellite positioning and short message technology is adopted, and a kind of data transmission communication apparatus using GPRS satellite is researched. After a large number of indoor debugging and field stability tests, it is proved that the control terminal of groundwater dynamic monitoring and communication developed based on GPRS satellite communication features stable data transmission, low power consumption, good resistance of wind, sand and moisture. It solves the transmission obstacle of groundwater monitoring data in the area without mobile phone signal, and realizes multi - mode groundwater monitoring communication.

Construction of gradient conductivity cellulose nanofiber/MXene composites with efficient electromagnetic interference shielding and excellent mechanical properties

The development of electronic communication technology leads to a complex electromagnetic (EM) environment, which is urgent for the design of high-performance EM interference (EMI) shielding materials. In this work, cellulose nanofiber (CNF) and MXene were used to construct ordered multi-layer composite films with a controllable conductive gradient by layer-by-layer vacuum filtration method. Especially, the films were composed of four transition layers (with low MXene content) and one reflection layer (with high MXene content), which not only effectively reduced the reflection of EM waves on the surface of materials but also greatly increased the multiple internal reflections of reflected EM waves. Besides, the dielectric loss provided by MXene, and the coordination of polarization with loss at the interfaces contribute to the outstanding EMI shielding effectiveness (EMI SE) (39 dB) and absorption effectiveness (28 dB) of the films. And practical application simulation proves that the composite membrane can limit the mobile phone communication signal. Moreover, the nacre-like structure was constructed by 1D CNF and 2D MXene, resulting in high tensile strength of 90.5 ± 6.7 MPa and elongation at a break of 8.0 ± 1.0%. Therefore, this work provided a feasible approach for preparing gradient composite films with high EMI shielding and mechanical properties, which is highly promising to be a competitive candidate for the application in the new-generation of intelligent electronic devices.

Spatio-Temporal Variation-Induced Group Disparity of Intra-Urban NO2 Exposure.

Previous studies on exposure disparity have focused more on spatial variation but ignored the temporal variation of air pollution; thus, it is necessary to explore group disparity in terms of spatio-temporal variation to assist policy-making regarding public health. This study employed the dynamic land use regression (LUR) model and mobile phone signal data to illustrate the variation features of group disparity in Shanghai. The results showed that NO2 exposure followed a bimodal, diurnal variation pattern and remained at a high level on weekdays but decreased on weekends. The most critical at-risk areas were within the central city in areas with a high population density. Moreover, women and the elderly proved to be more exposed to NO2 pollution in Shanghai. Furthermore, the results of this study showed that it is vital to focus on land-use planning, transportation improvement programs, and population agglomeration to attenuate exposure inequality.