Number Of Stations Research Articles

Neighborhoods Renewal Implications for the Post-Pandemic Era: A Study of COVID-19 Infections in Central Shanghai, China

Since the onset of the Coronavirus Disease 2019 (COVID-19), urban older neighborhoods have faced increased vulnerability, prompting research into neighborhood renewal and resilience. However, research on COVID-19 infection and influencing factors in China's older neighborhoods remains relatively scarce. This study analyzed COVID-19 infections in central Shanghai to identify neighborhood-level factors affecting transmission. Using principal component analysis (PCA) and person correlation coefficients (PCC) to process the data, we established multiple linear regression (MLR) and geographically weighted regression models (GWR). To explore nonlinear relationships, we incorporated the random forest method (RF). Results indicated that older neighborhoods had higher infection rates compared to newer ones. Socioeconomic and built environment factors significantly influenced infection rates. Specifically, higher population density, road network density, and the number of subway stations were positively correlated with increased infection rates. RF analysis revealed a complex, nonlinear relationship between the number of high-income residents and infection rates. This study integrates built environment, socioeconomic, and population characteristics factors using multiple modeling approaches to better understand their impact on infection rates. It also introduces research on mainland Chinese cities as case studies, offering valuable insights for updating older urban neighborhoods to enhance community resilience. However, the study did not fully consider the impact of policies at the time, and its findings are primarily applicable to older neighborhoods in cities similar to Shanghai. Future research should examine the effectiveness of various intervention policies, the long-term effects of neighborhood renewal on community resilience, and the applicability of these findings to other urban environments.

Potential Benefits of Seismic Monitoring for Ground-Shaking Estimation and Loss Assessment

ABSTRACT Seismic networks are fundamental to compute ground shaking in regions affected by destructive events, which can then be used for damage and loss assessment. Ground-motion data recordings can be used to estimate the event bias (or interevent residual) for one or multiple ground-motion models, as well as to condition the ground-shaking estimation process to reduce the intraevent residuals at sites near seismic stations. We evaluate how the error in the estimation of the event bias and ground shaking for a set of target sites can be reduced by incorporating an increasing number of seismic stations, using recordings from the 1999 M 7.7 Chi-Chi, Taiwan, earthquake and a large set of ground-motion fields for Taiwan using stochastic simulations. Then, we evaluate how the incorporation of data from seismic stations in the estimation of several impact metrics (i.e., economic losses, collapsed buildings, and fatalities) can reduce both the bias and the uncertainty, using the district of Lisbon (Portugal) as a case study. The results from this study indicate that the error in the estimation of the impact metrics can be reduced by one order of magnitude if at least 10 stations are considered, especially if the configuration of the seismic network considers the location of vulnerable buildings or the spatial distribution of earthquake risk.

A Simulation Analysis of the Coverage and Demand Suitability of the Firefighting Capacity in Complex Commercial Areas

The initial firefighting capacity of complex commercial areas depends on the service level and the location of micro firefighting facilities. In response to the issue of coverage by micro firefighting facilities in complex commercial areas, a graded progressive coverage model is established. This model includes distance-progressive coverage and firefighting service level attenuation coverage. The former integrates fairness and efficiency in fire planning, while the latter considers the adaptability between the demand points and the fire service levels. The objectives include maximizing the coverage matching degree, effective coverage rate, medium- and high-risk coverage rate, and overall coverage rate of the fire service point and the demand points. A genetic algorithm is designed to solve the model, where the construction level and the number of micro fire stations are varied to analyze changes in various indicators. Central Street, characterized by complex buildings and high pedestrian traffic, is selected as a case for the experiment. The results show that simply adjusting the construction level of micro fire stations increases the effective coverage rate by 2.5%. The graded progressive coverage model shows a turning point in the effective coverage rate and the overall coverage rate when the number of new micro fire stations is 14 or 10, with coverage rates of 76.1% and 93.2%, respectively. The maximum progressive coverage model shows a turning point in the overall coverage rate when 9 new stations are added, which is 10.5% lower than that of the graded coverage model; when 10 stations are added, the overall coverage rate is 11.2% lower. These findings demonstrate the effectiveness of the graded progressive coverage model.

Impact of station number and duration time per station on the reliability of Objective Structured Clinical Examination (OSCE) scores: a systematic review and meta-analysis

BackgroundThe Objective Structured Clinical Examination (OSCE) is a systematic and structured assessment tool that evaluates candidates’ professional medical skills in a simulated environment through a series of time-limited stations. The aim of this meta-analysis was to determine the optimal station number and duration time per station of OSCE to achieve good reliability.MethodsA comprehensive search was conducted across PubMed and Embase from inception until August 2024, without language restrictions. Studies were included if they provided data on the station number and duration time of OSCE, along with Cronbach’s alpha. A random-effects model was used to pool the data.ResultsA total of 23 studies encompassing 26 Cronbach’s alpha were finally included. Cronbach’s alpha values ranged from 0.43 to 0.93, and 11 studies demonstrated good internal consistency (Cronbach’s alpha ≥ 0.8). The analysis indicated that a design of 5–10 stations, with each station lasting less than 10 min, yielded the best internal consistency (Cronbach’s alpha = 0.88, 95% CI: 0.86, 1.00).ConclusionsThis meta-analysis suggests that the station number of OSCE falling in between 5 and 10, with each station time lasting no more than 10 min are likely to yield good reliability and strong internal consistency.

Historie a současnost meteorologických měření a pozorování v oblasti Jeseníků

The oldest known mention of meteorological observations in the area of interest is from 1816 Frývaldov (German: Freiwaldau, today’s town of Jeseník). Between 1840 and 1845, Dr. Heinisch observed the weather in the Karlova Studánka municipality. In 1851, the Central Institute for Meteorology and Earth Magnetism was founded in Vienna, which, however, was more important for the region of Bohemia. The foundation of the Natural Research Society in 1861 in Brno by Johann Gregor Mendel contributed to the enlargement of the meteorological station network in northern Moravia. The result of the activities of this association was, for example, the station of a meteorological station in Šumperk, established in 1865. One of the oldest meteorological stations with available meteorological data in the Czech Hydrometeorological Institute is the Bernartice station near Javorník at the foothills of the Rychleby Mountains (1848–1946). Another organization that had an influence on the development of meteorological stations in the Jeseníky Mountains region was the Hydrographic Commission for the Kingdom of Bohemia and especially its Ombrometric Section (1875). In 1876, observations began in Heřmanovice, Holčovice, Jeseník and Vrbno pod Pradědem. The Razová station has been observing since 1877, and the observation from Rýmařov has been preserved since 1879. Since 1881, meteorological observations have been carried out in Albrechtice near Rýmařov, in Branná or in Dětřichov, and in 1883 records from the first peak station on Králický Sněžník are also available (although only from a few years). A greater increase in the number of meteorological stations occurred in 1895 (13 new stations in the Jeseníky Mountains) as a result of the establishment of the k. k. Central hydrographic office at the Ministry of the Interior in Vienna (1893). Shortly after the floods in Moravia in July 1997, on September 15, 1997, the operation of the highest professional meteorological station in the Czech Republic at Praděd was terminated. Since January 1, 2004, the professional station at Šerák has been in operation. On October 27, 2019, an automatic weather station was established under the peak of Králický Sněžník at an altitude of 1,402m above sea level. On September 23, 2022, the automated weather station Nové Heřminovy was put into operation. The owner of the station is the Povodí Odry Enterprise. Since 2020, the Forestry and Game Management Research Institute has been operating an EMS Brno automated weather station in Švýcárna. The CHMI managed to establish cooperation with the Institute, and we use the data from this station to prepare climatological characteristic of the top parts of the Jeseníky Mountains. The installation of new snow measuring stations at Malý Děd and Pod Jelení studánkou took place in June 2024. These two stations thus complemented the ASNS type station (so-called snow measuring pillow, i.e. snow measuring sensor and “pillow”) for measuring water content of the total snow cover on Klepáčov, which has been operating since 2011. Since 2018, the CHMI regional office in Ostrava has operated several additional stations with air temperature measurements in the Jeseníky Mountains (Červenohorské sedlo, Dlouhé Stráně lower reservoir, Rejvíz, and Alfrédova myslivna) and from 2023, in cooperation with amateur meteorologists, three measurements in frosty locations (Heřmanovice, Moravský Kočov, Moravský Beroun). There are around 100 locations within an area of interest of the Jeseníky Mountains where meteorological stations with various observation programs existed or still exist. Currently, there are 41 stations under the management of the CHMI, Ostrava regional office.

A State-of-Health Estimation Method of a Lithium-Ion Power Battery for Swapping Stations Based on a Transformer Framework

Against the backdrop of automobile electrification, an increasing number of battery-swapping stations for electric vehicles have been launched to address the issue of slow battery charging under cold temperature conditions. However, due to the separation of the discharging and charging processes for lithium-ion batteries (LIBs) at swapping stations, and the circulation of batteries across different vehicles and stations, the operating data become fragmented, making it difficult to accurately identify the battery state-of-health (SOH). This study proposes a BiLSTM-Transformer framework that extracts the Constant Voltage Time (CVT) feature using only charging data, enabling the precise estimation of battery capacity degradation. Validation experiments conducted on battery samples under different operating temperatures showed that the model achieved a normalized RMSE of less than 1.6%. In ideal conditions, the normalized RMSE of the estimation reached as low as 0.11%. This model enables SOH estimation without relying on discharge data, contributing to the efficient and safe operation of battery swapping stations.

Analysis of the effect of inflatable mediastinoscopy esophagectomy and minimally invasive Mckeown esophagectomy combined with thoracoscopy and laparoscopy in the treatment of early esophageal cancer

Objective: To explore the operioperative and long-term outcomes of inflatable mediastinoscopic resection of esophageal carcinoma (IVMTE) and minimally invasive Mckeown resection of esophageal carcinoma (MIME) in early esophageal cancer. Methods: This is a retrospective cohort study. A retrospectively analysis was conducted on 176 patients with cT1N0M0 esophageal cancer who underwent IVMTE or MIME at the Department of Thoracic Surgery, Anhui Provincial Hospital Affiliated with Anhui Medical University from April 2017 to April 2019. There were 128 males and 48 females, aged (66.4±7.7) years (range: 45 to 87 years). General data, perioperative outcomes, pathological data of the tumors, and complications were recorded. Independent sample t-test, χ² test, and Wilcoxon rank-sum test was used to compare the data between the two groups. Propensity score matching was performed with gender, age, tumor location, differentiation degree, pT stage, pN stage, American Society of Anesthesiologists (ASA) classification, smoking history, and alcohol history were considered as covariates. The IVMTE group and MIME group were matched in a 1∶2 ratio using nearest neighbor match method with a caliper value of 0.02. Kaplan-Meier method was used to plot survival curves, with Log-rank test for univariate survival analysis. The Cox proportional hazards model was applied to analyze prognostic factors for overall survival, and subgroup stratification analysis was performed for pT stage. Results: After matching, the MIME group consisted of 54 cases, and the IVMTE group consisted of 27 cases. There were no statistically significant differences between the two groups in terms of gender, age, smoking history, alcohol history, ASA classification, tumor location, and other factors. The IVMTE group had shorter surgery time (M(IQR), 220 (45) minutes vs. 245 (56) minutes, Z=2.950, P=0.003) and less intraoperative blood loss (100 (50) ml vs. 125 (100) ml, Z=2.193, P=0.028) compared to the MIME group. There were no differences between the two groups in the number and quantity of lymph node stations dissected, and the IVMTE group was not at a disadvantage in terms of the number of lymph nodes dissected around the recurrent laryngeal nerve (all P>0.05). The 1-, 3-, and 5-year overall survival (OS) rates and recurrence-free survival (RFS) rates were not significantly different between the two groups (all P>0.05). Subgroup analysis showed no significant difference in OS and RFS rates between the pT1 and pT2 subgroups (all P>0.05). Multivariate Cox regression analysis suggested that ASA classification (HR=2.516, 95%CI: 1.126 to 5.624, P=0.025), pN stage (HR=2.485, 95%CI: 0.984 to 6.274, P=0.046), and whether adjuvant therapy was given postoperatively (HR=2.915, 95%CI: 1.304 to 6.515, P=0.009) were independent risk factors affecting 5-year OS rate. For 5-year RFS, pT stage (HR=0.403, 95%CI: 0.194 to 0.838, P=0.011), pN stage (HR=5.219, 95%CI: 2.401 to 11.346, P<0.01), and whether adjuvant therapy was given postoperatively (HR=5.644, 95%CI: 2.691 to 11.838, P<0.01) were independent risk factors, while the surgical approach was not an independent risk factor affecting patient prognosis. Conclusion: The short-term and long-term effect of IVMTE in the treatment of early esophageal cancer is good, and it can achieve effects comparable to MIME.

Microseism Amplitude and Wave Power in the Mediterranean Sea (1996–2023)

AbstractIn this work, we integrate seismic data recorded by nine coastal Mediterranean seismic stations and wave hindcast data for 1 January 1996 through 15 October 2023. We examine the relationships between the ocean wave‐generated microseism signal (the most continuous and ubiquitous seismic signal on Earth) in terms of temporally varying spectral content, root mean square amplitude, and microseism power spectral density, with the main features of principal ocean wave attributes, specifically significant wave heights, wave period and wave power. To explore relationships between microseism and sea state, we performed a correlation analysis between seismic root square mean amplitude and significant wave height time series for the entire Mediterranean Sea for 1996–2023, including retrieving long‐term trends for microseism energy and independently estimated wave power and calculating the Spearman correlation coefficient between the two trend time series. Despite the small number of stations available the analysis allows for a useful exploratory study on the microseism and its relationship with Mediterranean Sea state and wave power spanning 27 years. Given the recent increase in the number of regional seismic stations, the growth of data sharing, and the intensification of global warming and climate extreme events, the results and methods explored here can be further implemented and developed in coming years for coastal monitoring purposes in complement with other data sources.

Crustal Heterogeneity Onshore Central Spitsbergen: Insights From New Gravity and Vintage Geophysical Data

AbstractGravity data provide constraints on lateral subsurface density variations and thus provide crucial insights into the geological evolution of the region. Previously, gravity data from the Norwegian Arctic archipelago of Svalbard comprised an onshore regional gravity database with coarse station spacing of 2–20 km, offshore gravity profiles acquired in some fjords, airborne gravity, and satellite altimetry. The sparse regional point‐based onshore coverage hampered the direct integration of gravity data with seismic profiles acquired onshore Svalbard in the late 1980s and early 1990s. In April 2022, we acquired gravity data at 260 new stations along seven profiles from western to eastern Spitsbergen, with a cumulative length of 329 km. The profiles were acquired directly along selected seismic profiles and provide much closer station spacing (0.5–2 km) compared to the regional inland grid (2–20 km) acquired in the late 1980s (total number of onshore stations: 1,037). Having processed the data, we compared the first‐order density trends of our new data with the legacy regional grid. The new gravity data are consistent with the regional data, imaging a gravity low in the western part of the area underlying a foreland basin and a gravity high in the northwestern part of the area likely associated with a basement high or denser basement. We compare the new and vintage gravity using maps and profiles, linked to the known major tectonic features such as major basinal axes and fault zones, as well as other geophysical data sets including seismics and magnetics.

Ground and Space (LEO) Based GNSS Ionospheric Detection Using Chapman Function Constraint

AbstractLimited by the number and location distribution of ground stations, the ground based ionospheric detection using Global Navigation Satellite Systems (GNSS) technology suffers from low accuracy and poor reliability in some regions. To improve the performance of the global ionospheric model, this study combines the Continuously Operating Reference Station and the Low Earth Orbit (LEO) Satellite observation to conduct the ground and space‐based (G/SBased) joint ionospheric detection technique. With reference to the ionospheric radar data of the global ionospheric radio observatory, the performance of the G/SBased GNSS joint ionospheric detection technique was tested in quiet and disturbed geomagnetic environments. Results show that in the ground and space based joint mode, the distribution of ionospheric puncture points (IPPs) is uniform, thus effectively avoiding the problem of IPPs blank in the absence of ground stations. In the quiet geomagnetic environment, the ionospheric detection of the G/SBased joint mode has a remarkable performance improvement compared with the ground GNSS mode, with an average improvement of 55.51%. In the geomagnetically disturbed environment, the G/SBased joint mode still has high consistency with the ionospheric radar results, and the detection performance is better than that of the ground GNSS mode. This research shows that combining with ground GNSS and LEO satellite observation data can substantially provide the performance of GNSS ionospheric total electron content detection and can provide good data support for the construction of a global ionospheric refinement model.

Affecting factors and health risks of organophosphate esters in urban soil and surface dust in a typical river valley city based on local bivariate Moran's I and Monte-Carlo simulation

A total of 102 urban soil and surface dust samples were collected from Lanzhou of China to clarify the occurrences, sources, affecting factors, and health risks of 13 organophosphate esters (OPEs). The total concentration of 13 OPEs (Ʃ13OPEs) in urban soil and surface dust ranged from 80.1 to 749 and 244 to 4905ng/g, dominated by chlorinated OPEs (39.9% and 65.1%). The Ʃ13OPEs in the two media was higher in the central and eastern of Lanzhou due to local topography and wind direction. OPEs in the two media originated from industrial, traffic and commercial activities (37%–53.4%), atmospheric depositions (24.3%–31.3%), and OPEs-containing material emissions (14.5%–31.7%). Transport station number, residential/commercial area distribution, and road length were positively correlated with Ʃ13OPEs in the two media, suggesting that traffic activities are the main factors influencing the distribution of OPEs. Probabilistic non-cancer (< 1) and cancer (< 1×10-6) risks of human exposed to OPEs were low, mainly attributed to OPEs-containing material emissions (47.5%–62.0%) in urban soil and industrial/traffic activities (57.8%–92.2%) in surface dust. Reducing the frequency of human exposed to the two media and controlling the release of OPEs from pollution sources may mitigate population exposure risks.

The Development of an IoT-Based Palm Solid Waste Counting System for Empty Fruit Bunches in the Palm Oil Industry

The recent application of palm empty fruit bunches as solid waste directly on soil or as organic fertilizer has enhanced palm farms. Moreover, the co-products of this palm oil mill constitute a dependable metric for assessing mill processing performance, specifically regarding quantity and weight. The quantity of palm empty fruit bunches is usually ascertained through manual counting using a hand counter during processing. The imprecision in calculating palm empty fruit bunches is a limitation of this method, as operators sometimes perform erroneous calculations, overlook quantities, and produce contradictory results for mill management. To address this issue, the sector requires enhanced execution of a monitoring and counting system methodology. The aim of this community service project is to create an empty fruit bunches count station using an IoTbased palm solid waste counting system for use in palm mills. The Ministry of Industry - Politeknik Teknologi Kimia Industri (PTKI) Medan will engage in and oversee the advancement of Industry 4.0 within the industrial sector. The initiative was executed at Tanah Gambus Estate in Batubara Regency, North Sumatra. Assistance was provided by a palm mill partner associated with PT. Socfin Indonesia. The implementation of the empty fruit bunches palm oil counting system was conducted efficiently, facilitating optimal operations, real–time online monitoring, uninterrupted functionality exceeding 24 hours daily, swift assessment of the empty fruit bunches volume, immediate identification of traditional counting inaccuracies by operators and management, and its station provides benefits to the palm industry.

Development and validation of a predictive model for overall survival in esophageal squamous cell carcinoma post-esophagectomy: the role of lymph node metastatic Stations.

Esophageal squamous cell carcinoma (ESCC) poses a substantial healthcare challenge, particularly in areas such as East Asia. The pathologic nodal (pN) stage of ESCC remains a controversial factor. Accurately predicting overall survival (OS) after esophagectomy is crucial for treatment planning and improving treatment outcomes. An analysis was conducted using data from our hospital [Details blind for peer review], spanning from January 2010 to December 2017. Our study aimed to examine the clinicopathological characteristics, lymph node resection at individual stations, and treatment details of patients with ESCC who underwent esophagectomy. In addition, a novel nodal stage (N stage) based on the number of lymph node metastasis (LNM) stations and devised a prediction model for OS using the pN stage and the newly proposed N stage. After analysing 49 indicators through univariate and multifactorial analyses, 25 of the most significant factors affecting OS after esophagectomy were identified. Further analysis using least absolute shrinkage and selection operator regression revealed six key factors. Models were developed based on the pN stage and the newly introduced N stage. Evaluation of the area under the curve indicated that Model 2 exhibited slightly superior clinical utility compared to Model 1. Our study demonstrates that the newly introduced N stage, based on the number of LNM stations, exhibits comparable performance to the current American Joint Committee on Cancer/Union for International Cancer Control pN system, with a slight advantageous edge.

Research on multi-objective hierarchical site selection coverage of fire station

The fire station location has essential theoretical and practical values, not only in terms of maintaining the safety of life and property, but also enriching the optimization theory of site selection problems. To study the multi-objective siting problem of fire stations, we firstly divided demand areas and fire stations into three levels to form a comprehensive hierarchical emergency coverage network covering fire risk areas. Secondly, the nodes of the original location of the fire station were added to the set of nodes of the planned construction of the fire station. By introducing the coverage attenuation function, the multi-objective level fire station location model covering the maximum fire risk value and the minimum construction cost of the fire station was established. Then, the epsilon constraint method was used to address the multi-objective model, followed by designing the genetic algorithm based on the problem characteristics for solutions. To validate the effectiveness of the proposed model and algorithm, numerical experiments were performed, which took an urban area in China as an example. The solutions indicated that although retaining more of the original fire stations reduced the siting costs, most strategies tended to fail to cover higher values of fire risk, and the service coverage increases with the number of new fire stations. Additionally, sensitivity analysis was conducted to explore the effect of different parameters on the maximum fire risk value that can be covered by a fire station. A compromise coordinated siting scheme with a hierarchy of fire stations can be obtained by solving the proposed model. It can provide decision support for related departments to develop optimal siting configurations.

Minimization of Construction and Operation Costs of the Fuel Cell Bus Transportation System

This paper took the actual bus transportation system as the object, simulated the operating state of the system, replaced all the current diesel engine buses with fuel cell buses using electrolysis-produced hydrogen, and completed the existing timetable and routes. In the study, the numbers of hydrogen production stations and hydrogen storage stations, the maximum hydrogen storage capacity of the buses, the supplementary hydrogen capacity of the buses, and the hydrogen production capacity of the hydrogen storage stations were used as the optimal adjustment parameters for minimizing the ten-year construction and operating costs of the fuel cell bus transportation system by the artificial bee colony algorithm. Two hydrogen supply methods, decentralized and centralized hydrogen production, were analyzed. This paper used the actual bus timetable to simulate the operation of the buses, including 14 transfer stations and 112 routes. The results showed that the use of centralized hydrogen production and partitioned hydrogen production transfer stations could indeed reduce the construction and operating costs of the fuel cell bus transportation system. Compared with the decentralized hydrogen production case, the construction and operating costs could be reduced by 6.9%, 12.3%, and 14.5% with one, two, and three zones for centralized hydrogen production, respectively.

Two-stage optimization for site selection and resource allocation of metro rescue stations

Metro systems serve as the backbone of modern urban transportation, with elevators being critical facilities within metro stations. Aiming at the problem of elevator emergency rescue in urban subway, a two-stage optimization model of location selection and resource allocation is proposed. In the first stage, based on the distribution and coverage of metro stations, we construct a Minimum Site Selection Model and a Maximum Coverage Model with a Fixed Number of Rescue Stations. Utilizing a mixed-integer programming approach, we determine the optimal layout for rescue stations, ensuring that the minimum number of stations covers all target locations. In the second stage, we develop a resource allocation model that optimizes the distribution of limited resources among rescue stations by balancing utility and cost. To address this nonlinear mixed-integer programming problem, we conduct a comparative analysis of the efficiency and effectiveness of five heuristic algorithms in resource allocation. The results indicate that Particle Swarm Optimization (PSO) and Tabu Search (TS) achieve the highest benefits under a concentrated resource allocation strategy, while Genetic Algorithm (GA) and Ant Colony Optimization (ACO) perform well in balanced resource distribution. This research provides theoretical support for emergency management in urban metro systems.

Inspection Path Planning of Mobile Communication Base Stations Based on Automatic UAV Nest

With the development of 5G mobile networks, the number of mobile communication base stations in China has increased rapidly, and regular inspection and maintenance are required. Traditional manual inspection has some shortcomings and limitations. In recent years, the development of drones and drone nest technology has made drone inspection feasible. Since the automation level of traditional manually controlled drone inspection is low, this paper proposes a base station inspection scheme based on drone nests. By establishing an inspection model and using the simulated annealing algorithm to solve the TSP problem, the drone inspection path is planned to improve the inspection efficiency and the unmanned and automated inspection level. In this paper, the simulation experimental results show that the algorithm can effectively obtain the global optimal solution in a relatively short time, realize the path planning of drone automatic inspection of base stations, and effectively improve the inspection efficiency of drones.

Tethered Balloon Cluster Deployments and Optimization for Emergency Communication Networks.

Natural disasters can severely disrupt conventional communication systems, hampering relief efforts. High-altitude tethered balloon base stations (HATBBSs) are a promising solution to communication disruptions, providing wide communication coverage in disaster-stricken areas. However, a single HATBBS is insufficient for large disaster zones, and limited resources may restrict the number and energy capacity of available base stations. To address these challenges, this study proposes a cluster deployment of tethered balloons to form flying ad hoc networks (FANETs) as a backbone for post-disaster communications. A meta-heuristic-based multi-objective particle swarm optimization (MOPSO) algorithm is employed to optimize the placement of balloons and power control to maximize target coverage and system energy efficiency. Comparative analysis with a stochastic algorithm (SA) demonstrates that MOPSO converges faster, with significant advantages in determining optimal balloon placement. The simulation results show that MOPSO effectively improves network throughput while reducing average delay and packet loss rate.

Monitoring May 2024 solar and geomagnetic storm using broadband seismometers

The abrupt variations in the magnetic field due to the May 2024 geomagnetic storm have been recorded by broadband seismometers distributed around the world for a time interval of more than 55 h. Signals related to magnetic field variations can be identified in seismic data for frequencies below 10 mHz, but are clearer between 1.5 and 5 mHz, the frequency band corresponding to Pc5 magnetic pulsations. The number of seismological stations that detect these signals varies significantly between the various seismic networks analyzed, but in general they do not exceed 50–60%. The origin of these signals appears to be related to the interaction between telluric currents induced by magnetic field disturbances associated with the geomagnetic storm and the detection systems in broadband sensors, which measure the current intensity necessary to keep the mass of the seismometer fixed. Although detailed calibration of each seismometer will be necessary to use the seismic data to model the waveforms and amplitudes of the magnetic pulsations, the analysis of this data provides a significant densification with respect to the magnetic observatory data, as is of interest to analyze the temporal and regional evolution of the magnetics disturbances associated to the May 2024 solar storm.

Longitudinal Monitoring of Electric Vehicle Travel Trends Using Connected Vehicle Data

Historically, practitioners and researchers have used selected count station data and survey-based methods along with demand modeling to forecast vehicle miles traveled (VMT). While these methods may suffer from self-reporting bias or spatial and temporal constraints, the widely available connected vehicle (CV) data at 3 s fidelity, independent of any fixed sensor constraints, present a unique opportunity to complement traditional VMT estimation processes with real-world data in near real-time. This study developed scalable methodologies and analyzed 238 billion records representing 16 months of connected vehicle data from January 2022 through April 2023 for Indiana, classified as internal combustion engine (ICE), hybrid (HVs) or electric vehicles (EVs). Year-over-year comparisons showed a significant increase in EVMT (+156%) with minor growth in ICEVMT (+2%). A route-level analysis enables stakeholders to evaluate the impact of their charging infrastructure investments at the federal, state, and even local level, unbound by jurisdictional constraints. Mean and median EV trip lengths on the six longest interstate corridors showed a 7.1 and 11.5 mile increase, respectively, from April 2022 to April 2023. Although the current CV dataset does not randomly sample the full fleet of ICE, HVs, and EVs, the methodologies and visuals in this study present a framework for future evaluations of the return on charging infrastructure investments on a regular basis using real-world data from electric vehicles traversing U.S. roads. This study presents novel contributions in utilizing CV data to compute performance measures such as VMT and trip lengths by vehicle type—EV, HV, or ICE, unattainable using traditional data collection practices that cannot differentiate among vehicle types due to inherent limitations. We believe the analysis presented in this paper can serve as a framework to support dialogue between agencies and automotive Original Equipment Manufacturers in developing an unbiased framework for deriving anonymized performance measures for agencies to make informed data-driven infrastructure investment decisions to equitably serve ICE, HV, and EV users.