Wide-area IoT sensor networks require efficient data collection mechanisms when sensors are dispersed over large regions with limited communication infrastructure. Unmanned aerial vehicle (UAV)-mounted Mobile Base Stations (MBSs) provide a flexible solution; however, their limited onboard energy and the strict energy budgets of sensors necessitate carefully optimized tour planning. In this paper, we introduce the Mobile Base Station Optimal Tour (MOT) problem, which seeks a minimum-cost, non-revisiting tour over a subset of candidate stops such that the union of their coverage regions ensures complete sensor data collection under a global sensor energy constraint. The tour also avoids restricted areas. We formally model the MOT problem as a combinatorial optimization problem, which is NP-complete. Owing to its computational intractability, we develop a polynomial-time greedy heuristic that jointly considers travel cost and incremental coverage gain while avoiding restricted areas. Using simulations, we obtain tours with low cost, complete sensor coverage, and faster execution. Our proposed greedy algorithm outperforms state-of-the-art approaches in terms of a performance indicator defined as the product of tour length and algorithm execution time, achieving an improvement of 39.15%. The proposed framework provides both theoretical insight into the structural complexity of MBS-assisted data collection and a practical algorithmic solution for large-scale IoT deployments.
Urban boundary delineation is essential for understanding spatial structure, monitoring urbanization, and guiding sustainable land management. Nighttime light (NTL) data effectively capture urban dynamics across multiple spatial scales. This study integrates NTL data with spectral indices to delineate the urban boundaries of the Barcelona Metropolitan Region (BMR) from 2006 to 2018. Through multivariate regression analysis, the normalized difference vegetation index (NDVI) and normalized difference built-up index (NDBI) are identified as key indicators of urban spatial heterogeneity. These indices are combined with brightness thresholds derived from three NTL datasets, DMSP-OLS, Black Marble, and VIIRS, to delineate urban areas more accurately. Results indicate that VIIRS achieved the highest precision in identifying construction land and urbanized areas, with an overall accuracy exceeding 90% and consistency with population density and GDP distribution. A strong spatial correlation between urban distribution and the NDVI–NDBI relationship is confirmed in the BMR. The coupling of multisource remote sensing data improves the accuracy, stability, and reliability of urban boundary delineation, overcoming single-source limitations. This integrated method supports urban planning and sustainable land management through consistent, objective urban mapping and offers a practical reference for applying remote sensing technologies to monitor urbanization dynamics across broader spatial and temporal contexts.
Abstract The role that cities play in enhancing biodiversity conservation is increasingly recognized. However, since locations for conservation within metropolitan areas are often spatially restricted, and management for biodiversity may conflict with interventions on behalf of other desirable objectives, it is important that the outcomes of urban conservation projects are carefully monitored. Such monitoring is relatively rare. In this study we explored the value of employing soundscape analysis to provide a holistic evaluation of biotic communities at urban sites undergoing different forms of vegetation management. Using readily affordable audio recorders, we evaluated soundscapes in replicated areas within a 481-hectare urban park in Chicago, Illinois. Areas within the park are managed to achieve multiple objectives including both recreational use and nature conservation. We found that relatively small areas within the park that had been subjected primarily to restorative vegetation management supported different acoustic environments with higher avian activity and more prevalent biophonic sound than was the case in managed lawn spaces. The use of a variety of acoustic indices supplemented the analysis of these soundscapes, and whereas all indices affirmed seasonal differences, the Acoustic Complexity Index (ACI) was more helpful than the other indices we employed in discriminating between management practices. We conclude that vegetation management employed even at a small spatial scale in an urban environment can enhance faunal diversity, and that these results can be evaluated using inexpensive sound monitoring equipment.
Aesthetics of cities. City planning and beautifying, Cities. Urban geography
R Blake Buchalter, Paul R Gunsalus, Madeleine M Blazel
et al.
Spatial access to care describes the ability of populations to travel to healthcare providers. Existing spatial access to care studies frequently utilize metrics constructed using car-specific travel to providers, potentially underestimating access in populations using other travel modalities (i.e., walking/transit). We present a novel multi-travel modality spatial access to care composite measure, a corresponding temporally representative open-source data resource, and a stratified analysis of neighborhood rural/urban and socioeconomic disparities. We utilized quarterly 2016-2020 Centers for Medicare and Medicaid Services Doctors and Clinicians National Downloadable Files to compute temporally representative multi-modal spatial accessibility to 56 healthcare provider classifications in U.S. census tracts and block groups. We performed tract-level analyses stratified by 2010 Rural-Urban Commuting Area Codes and 2016 Area Deprivation Index for a subset of provider types. We found that 1) non-metropolitan areas have poorer multi-modal spatial access to primary (P < 0.001), specialty (P < 0.001), pulmonology (P < 0.001), nephrology (P < 0.001), and cancer care (P < 0.001) than metropolitan areas both cross-sectionally and over time and 2) multi-modal primary care access was substantially poorer than multi-modal specialty care access in 2016 and this trend did not improve over time. We also produced a data resource for many provider types and an interactive spatial access map for a subset of provider classifications. After stratifying, we found significant disparities in spatial access to primary care, specialty care, pulmonology, nephrology, and cancer care in non-metropolitan areas. Our multi-modal spatial access measure and corresponding data resource may be useful for population health and clinical studies, public health entities, community stakeholders, health systems, and policymakers.
Urban Foraging (UF) has gained increasing attention in recent years as a means of engaging with nature in urban environments and as an adaptive strategy for urbanization and green space reduction. While research on UF has been conducted in Western countries, studies in Japan remain scarce. This study aims to analyze UF practices and their impact in Tokyo metropolitan area. Through interviews with UF practitioners and local government officials, as well as fieldwork in Tokyo and surrounding areas, this study reveals key patterns in UF engagement. Findings indicate that individuals who forage more frequently tend to collect a greater variety of resources, including plants, fungi, and even engage in hunting and fishing. Common foraging sites include rivers, parks, and vacant lots, with food being the primary motivation. Many practitioners have childhood foraging experiences, and social media and community networks serve as important sources of knowledge. Furthermore, UF appears to influence practitioners' perceptions of nature. From an administrative perspective, many municipalities prohibit foraging in parks, although some adopt a more flexible stance. The study highlights the emergence of ethical considerations and informal regulations among urban foragers. Through food consumption, practitioners develop a deeper awareness of their relationship with urban nature. This study suggests that UF could foster novel human-nature relationships and enhance urban green space utilization. However, further research is needed to examine gender, socioeconomic differences, homelessness, foreign urban foragers, commercial exploitation, and overforaging concerns.
Abstract Background To explore the perceptions and experience of oral health management among rural older people in China. Methods Qualitative methodologies were used in this study. Face-to-face semi-structured interviews were conducted. Thirteen older adults in rural areas were purposively sampled at two metropolitan hospitals in Hunan, China. The data were transcribed and thematically analyzed, and MAXQDA software was used to assist with coding. Results Three overarching major themes and ten sub‑themes capturing the perceptions and experience of oral health management among rural older people were identified. Three themes emerged from the thematic analysis: oral health cognitive bias, poor management behaviors, and limited oral health services. Oral health management as a whole is negative, oral health behaviors are poor, oral health service utilization is limited. Conclusions Based on these findings, there is great scope here for improving the current status of oral health for rural older people around awareness, behavior, and access. Oral health education, improved oral health services and primary oral health promotion are warranted.
Makerspaces (MS) represent a type of new working space (NWS), a subject addressed by numerous researchers. Nevertheless, among the abundance of publications on NWS, only a limited number discuss the detailed distribution of MS and address the significant issue of their location factors. This article aims to supplement these research gaps based on the example of Polish makerspaces, through a comprehensive database of Polish NWS and spatial analysis conducted through GIS systems. According to the results, there is a predominance of MS in the main metropolitan centers, alongside a rising significance in peripheral areas while a co‑occurrence of MS with other institutions focusing on innovation, creativity and education is recorded. It is also pointed out that location factors related to transportation are mainly found in large urban centers, but not noticeable elsewhere. Through the use of in‑depth interviews, the author points to the significant relevance of social factors in the MS creation phase, together with accessibility and infrastructure‑related factors. In addition, crucial components impacting on MS establishment include the engagement of MS members, municipal support, location and the characteristics of the MS environment. Lastly, the validity of the rules and regulations of organizations supporting the creation of MS are outlined.
Rapid urbanization in emerging nations such as Ethiopia encourages participants in the area to consider the sustainability and balanced growth of metropolitan centers from a variety of angles and to offer suitable solutions. This study aims to comprehend how urban land use influences the efficiency and connection of road networks, which in turn affects how accessible different parts of the city are, to determine the influencing factors and critical indicators that enable a systematic categorization of subcity accessibility from the perspectives of urban land use. Geographic information system (GIS) techniques are used to gather and analyze precise geographical data on road networks, land use patterns, and other pertinent properties. In addition, a regression model is created to measure the effect of land use features on the accessibility of the road network. The primary questionnaire data are used to estimate the current situation of road accessibility and are used in the study validation process. This research has incorporated qualitative and quantitative approaches to sustainability. The findings imply that residential areas are 90% significant in making transport along the city, and 98% of the accessibility of the road network is dependent on land use features, including road density and subcity areas. Among the subcities, Bole, Kirkos, and Arada have 87% road network accessibility and better access to public transportation. Overall, these techniques emphasize the value of spatial analytic tools in planning procedures to better comprehend and control the intricate relationships between transportation and land use dynamics and to assist in the sustainable design and growth of cities.
Transportation engineering, Transportation and communications
To empirically study the policy impact of a National New Area on the local economy, this paper evaluates the effect of the Zhoushan Archipelago New Area on local GDP growth rate and economic efficiency. By collecting input and output data from 20 prefectural-level cities in Jiangsu, Zhejiang, and Anhui provinces from 1995 to 2015, we estimate the economic efficiency of these cities using data envelopment analysis. Subsequently, we construct counterfactuals for Zhoushan by selecting comparable cities from the dataset, excluding Zhoushan, and applying a panel data approach. The difference between the actual and counterfactual values for GDP growth rate and economic efficiency in Zhoushan is analyzed to determine the treatment effect of the National New Area policy. The research reveals that in the initial four years, the New Area policy enhanced Zhoushan's economic efficiency but negatively affected its GDP growth rate. This influence gradually disappeared after four years. Further analysis suggests that the policy's effect on GDP growth rate varies with the level of economic development in different regions, having a more substantial impact in less developed areas. Therefore, we conclude that establishing a New Area in relatively undeveloped zones is more advantageous.
Quantum fluctuations of the spacetime metric induce an uncertainty in the horizon area of a black hole. Working in linearized quantum gravity, we derive the variance in the area of a four-dimensional Schwarzschild black hole from the renormalized graviton propagator. We find that the standard deviation of the horizon area scales as the product of the Schwarzschild radius and the Planck length. For macroscopic black holes, the quantum uncertainty is therefore enormous in Planck units.
In Yaeum-dong, a residential area near the industrial complex, SIFT-MS, which enables real-time continuous measurement, was used to identify the characteristics of VOCs and odorous substances. When looking at the concentrations by chemical substance group, aliphatic hydrocarbons accounted for a significant portion, showing different characteristics from other large cities. This indicates that the Yaeum-dong area is directly affected by the emission source of the nearby petrochemical complex. As an individual substance, ammonia showed the highest concentration among HAPs. Seasonal HAPs concentrations generally tended to be high in summer and low in winter. When examining concentrations by time of day, it showed characteristics of industrial areas affected by VOCs scattered and volatilized in national industrial complexes. In addition, it was confirmed that the characteristics of urban areas appearing in general metropolitan traffic congestion zones appeared at the same time. Compared with the results of other previous studies, in general, there was no significant difference in concentrations from the results of measurements in residential areas near petrochemical complexes. And it showed a much lower concentrations than the measured value in industrial complex. As a result of CPF analysis for estimating the source of pollutants, most HAPs showed high concentrations in the south wind direction, indicating that the measurement point was affected by the industrial complex.
Dong Hyuk Jung, Dong Hyuk Jung, Byoungjin Park
et al.
BackgroundThe combination of gamma-glutamyl transferase (GGT) and high-density lipoprotein cholesterol (HDL-C) (GGT/HDL-C) is a novel noninsulin-based marker for assessing the risk of nonalcoholic fatty liver disease and type 2 diabetes mellitus. However, whether the GGT/HDL-C ratio is related to the risk of incident cardiovascular disease (CVD) risk is not well known. Therefore, we aimed to investigate the longitudinal effect of GGT/HDL-C ratio on incident CVD risk in three large cohorts of Korean men and women.MethodsData were assessed from 27,643 participants without CVD from the Korean Genome and Epidemiology Study (KoGES), Health Risk Assessment Study (HERAS), and Korea Health Insurance Review and Assessment (HIRA) (HERAS-HIRA) datasets. The participants were divided into four groups according to the GGT/HDL-C quartiles. We prospectively assessed hazard ratios (HRs) with 95% confidence intervals (CIs) for CVD using multivariate Cox proportional-hazard regression models over a 50-month period following the baseline survey.ResultsDuring the follow-up period, 949 patients (3.4%; 529 men and 420 women) developed CVD. The HRs of CVD for GGT/HDL-C quartiles 2-4 were 1.36 (95% CI, 0.91–2.02), 1.54 (95% CI, 1.05–2.26), and 1.66 (95% CI, 1.12–2.47) after adjusting for metabolic parameters in women, but GGT/HDL-C did not show a trend toward increases in incident CVD in men. Regional discrepancies were evident in the results; the increase in HR in the metropolitan hospital cohort was more pronounced than that in the urban cohort, and the risk was not increased in the rural cohort.ConclusionGGT/HDL-C ratio may be a useful predictive marker for CVD in women. Furthermore, the prevalence of CVD was strongly correlated with the GGT/HDL-C ratio in metropolitan areas, and this correlation was more significant than that observed with GGT or HDL-C in isolation.
Diseases of the endocrine glands. Clinical endocrinology
Increasing demand for energy due to population growth and global warming has led to numerous environmental issues such as deforestation, destruction of the ozone layer, drought, storms, and floods. These have encouraged researchers to seek new ways to use clean, renewable energies. The construction of Zero Energy buildings in Iran cities can be a significant step forward in economic development and pollution reduction in metropolitan areas. This study aims to identify and prioritize suitable cities in Iran to build Zero Energy buildings. For this purpose, the fuzzy Delphi and multi-attribute decision-making (MADM) methods have been used. The cities that are suitable for the construction of zero-energy buildings were selected through interviews with individuals who are experts in the fields of architecture, urban planning, and energy management and who are familiar with the construction of Zero Energy buildings, as well as considering the results of previous research and the characteristics of different cities. Then, with the fuzzy Delphi method, the necessary indicators for the priority of the selected cities were determined, and their weight was determined. After that, the cities were prioritized using MADM methods. The results showed that Yasuj, Shiraz, Tabriz, and Arak are suitable cities to build Zero Energy buildings in Iran.
This study was carried out to assess the carbon budget of local governments in South Korea. The carbon budget was obtained from the difference between net ecosystem productivity (NEP) that the natural ecosystem displays, and carbon dioxide emissions calculated from energy consumption in each local government. NEP was obtained from the difference between net primary productivity, measured by an allometric method, and soil respiration, measured with EGM-4 in natural forests and artificial plantations. Heterotrophic respiration was adjusted to 55% level of the total soil respiration based on existing research results. A field survey to obtain information for components of the carbon cycle was conducted in Cheongju (central Korea) and Yeosu (southern Korea). <i>Pinus densiflora</i>, <i>Quercus acutissima,</i> and <i>Quercus mongolica</i> (central Korea) and <i>P. densiflora</i> and <i>Q. acutissima</i> (southern Korea) forests were selected as the natural forests. <i>Pinus rigida</i> and <i>Larix kaempferi</i> (central Korea) and <i>P. rigida</i> (southern Korea) plantations were selected as the artificial plantations. Vegetation types were classified by analyzing LandSat images by applying a GIS program. CO<sub>2</sub> emissions were the highest in Pohang, Gwangyang, and Yeosu, where the iron and the petrochemical industrial complexes are located. CO<sub>2</sub> emissions per unit area were the highest in Seoul, followed by Pohang and Gwangyang. CO<sub>2</sub> absorption was the highest in the Gangwon province, where the forest area ratio to the total area is the highest, and the lowest in the metropolitan areas such as Seoul, Incheon, Daegu, Daejeon, and Gwangju. The number of local governments in which the amount of absorption is more than the emission amount was highest in Gangwon-do, where 10 local governments showed a negative carbon budget. Eight, seven, five, five, three, and three local governments in Gyeongsangbuk-do, Jeollanam-do, Gyeongsangnam-do, Jeollabuk-do, Gyeonggi-do, and Chungcheongbuk-do, respectively, showed a negative carbon budget where the amount of carbon absorption was greater than the emission amount. The carbon budget showed a very close correlation with carbon emission, and the carbon emission showed a significant correlation with population size. Moreover, the amount of carbon absorption showed a negative correlation with population size, population density, and non-forest area, and a positive correlation with the total area of the forest, coniferous forest area, and broad-leaved forest area. Considering the reality that carbon emissions exceed their absorption, measures to secure absorption sources should be considered as important as measures to reduce carbon emissions to achieve carbon neutrality in the future. As a measure to secure absorption sources, it is proposed to improve the quality of existing absorption sources, secure new absorption sources such as riparian forests, and efficiently arrange absorption sources.
Phenological changes caused by urbanization may provide evidence of how vegetation responds to global warming. However, the phenological characteristics of vegetation in metropolitan areas have been poorly studied, especially in terms of spatiotemporal variations. In this study, we explored the applicability of Local Climate Zones (LCZs) to investigate the spatiotemporal variations in urban vegetation phenology by linking MODIS-derived phenology metrics with LCZs in the Austin metropolitan area in Texas, USA. We extracted three vegetation phenology metrics from MODIS data between 2008 and 2018, including the start of growing season, end of growing season, and length of the growing season (i.e. SOS, EOS, and LOS, respectively). The results showed that during the study period, the EOS and SOS gradually advanced, while LOS showed no obvious change. Statistical analysis was conducted to examine the spatiotemporal variations of the phenology metrics among different LCZs and along “Urban-Rural Gradients” (URGs). There were 37.5%, 75.0%, and 74.3% pairs of LCZs, indicating statistically significant phenological differences in terms of SOS, EOS, and LOS in 2012, respectively. In contrast, most pairs of URGs showed almost no differences in phenological metrics, especially in EOS. Geographically, SOS showed a fluctuating change with an advancing tendency, whereas the EOS decreased very slowly with distance from the city center (i.e. along the URGs). LCZs can be used to help identify distinctive phenology metrics with statistically significant differences, especially in EOS and LOS. Compared to URGs, LCZs offer a unique analytical framework for studying urban ecosystem patterns, functions, and dynamics. Lastly, LCZs can enable the identification of sensitive areas for ecological protection in support of sustainable urban development and environmental stewardship.
A. A. Pishchimova, N. S. Smirnov, D. A. Ezenkova
et al.
Josephson superconducting qubits and parametric amplifiers are prominent examples of superconducting quantum circuits that have shown rapid progress in recent years. With the growing complexity of such devices, the requirements for reproducibility of their electrical properties across a chip have become stricter. Thus, the critical current $I_c$ variation of the Josephson junction, as the most important electrical parameter, needs to be minimized. Critical current, in turn, is related to normal-state resistance the Ambegaokar-Baratoff formula, which can be measured at room temperature. Here, we focus on the dominant source of Josephson junction critical current non-uniformity junction area variation. We optimized Josephson junctions fabrication process and demonstrate resistance variation of $9.8-4.4\%$ and $4.8-2.3\%$ across $22{\times}22$ $mm^2$ and $5{\times}10$ $mm^2$ chip areas, respectively. For a wide range of junction areas from $0.008$ $μm^2$ to $0.12$ $μm^2$ we ensure a small linewidth standard deviation of $4$ $nm$ measured over 4500 junctions with linear dimensions from $80$ to $680$ $nm$. The developed process was tested on superconducting highly coherent transmon qubits $(T_1 > 100\:μs)$ and a nonlinear asymmetric inductive element parametric amplifier.
The area method is a decision procedure for geometry developed by Chou et al. in the 1990's. The method aims to reduce the specified hypothesis to an algebraically verifiable form by applying elimination lemmas. The order in which the lemmas are applied is determined by the stated conjecture and the underlying geometric construction. In this paper we present our implementation of the area method for Euclidean geometry as a stand-alone Mathematica package.
We prove that area-minimizing submanifolds are not generically smooth, settling a conjecture of White that asks the generic smoothness of area-minimizing submanifolds. We furthermore establish a lower bound on the Hausdorff dimension of the singular sets of area-minimizing submanifolds with respect to open sets of Riemannian metrics. The lower bound is $\max\{d-5,d-c\},$ where $d$ denotes the dimension of the submanifold and $c$ denotes the codimension.
A physical system is said to satisfy a thermal area law if the mutual information between two adjacent regions in the Gibbs state is controlled by the area of their boundary. Thermal area laws have been derived for systems with bounded local interactions such as quantum spin systems. However, for lattice bosons these arguments break down because the interactions are unbounded. We rigorously derive a thermal area law for a class of bosonic Hamiltonians in any dimension which includes the paradigmatic Bose-Hubbard model. The main idea to go beyond bounded interactions is to introduce a quasi-free reference state with artificially decreased chemical potential by means of a double Peierls-Bogoliubov estimate.
Monitoring urban area expansion through multispectral remotely sensed data and other geomatics techniques is fundamental for sustainable urban planning. Forecasting of future land use land cover (LULC) change for the years 2034 and 2050 was performed using the Cellular Automata Markov model for the current fast-growing Epworth district of the Harare Metropolitan Province, Zimbabwe. The stochastic CA–Markov modelling procedure validation yielded kappa statistics above 80%, ascertaining good agreement. The spatial distribution of the LULC classes CBD/Industrial area, water and irrigated croplands as projected for 2034 and 2050 show slight notable changes. For projected scenarios in 2034 and 2050, low–medium-density residential areas are predicted to increase from 11.1 km<sup>2</sup> to 12.3 km<sup>2</sup> between 2018 and 2050. Similarly, high-density residential areas are predicted to increase from 18.6 km<sup>2</sup> to 22.4 km<sup>2</sup> between 2018 and 2050. Assessment of the effects of future climate change on potential soil erosion risk for Epworth district were undertaken by applying the representative concentration pathways (RCP4.5 and RCP8.5) climate scenarios, and model ensemble averages from multiple general circulation models (GCMs) were used to derive the rainfall erosivity factor for the RUSLE model. Average soil loss rates for both climate scenarios, RCP4.5 and RCP8.5, were predicted to be high in 2034 due to the large spatial area extent of croplands and disturbed green spaces exposed to soil erosion processes, therefore increasing potential soil erosion risk, with RCP4.5 having more impact than RCP8.5 due to a higher applied rainfall erosivity. For 2050, the predicted wide area average soil loss rates declined for both climate scenarios RCP4.5 and RCP8.5, following the predicted decline in rainfall erosivity and vulnerable areas that are erodible. Overall, high potential soil erosion risk was predicted along the flanks of the drainage network for both RCP4.5 and RCP8.5 climate scenarios in 2050.