Optimal Base Station Network Based on Topological Data Analysis

The decision of which base stations need to be removed due to the cost is always a difficult problem, because the influence on the cover rate of the network caused by the removal should be kept to a minimum. However, the common methods to solve this problem such as K-means Clustering show a low accuracy. Barcode, which belongs to TDA, has the possibility to show the result by identifying the Persistent Homology of base station network. This essay mainly illustrates the specific problem of optimal base station network, which applies the TDA(Topological Data Analysis) methods to find which base stations need removing due to the cost K-means Clustering and Topological Data Analysis methods were mainly used. With the simulated distribution of telecommunication users, K-means Clustering algorithm was used to locate 30 best base stations. By comparing the minimum distance between the results (K=25 and K=30), K-means Clustering was used again to decide base station points to be removed. Then TDA was used to select which 5 base stations should be removed through observing barcode. By repeating above steps five times, Finally the average and variance of cover area in original network, K-means Clustering and TDA were compared. The experiment showed that the average cover rate of original network was 81.20% while the result of TDA and K-means Clustering were 92.13% and 89.87%. It was proved by simulation that it is more efficient to use TDA methods to construct the optimal base station network.

Threats and prospects for the development of operators in the market of light petroleum products of Ukraine

The study of the market of light petroleum products of Ukraine made it possible to establish that the market is highly competitive and is growing at an average pace. The main operators on it are FPG "Privat" (gas station networks "Avias", "ANP", "Sentosa Oil", etc.), PJSC "Ukrnafta" (gas station network "UKRNAFTA"), PEG "Continental" (gas station network "WOG"), JSC "Concern "Galnaftogaz" (gas station network "OKKO"). These companies, as well as international gas stations networks, occupy the best competitive positions in the market. In the nearest future, the entry of new companies into the market is not forecasted. Oil refinery companies in Ukraine import oil and products of its processing, and their own oil and gas fields are not developed. Foreign companies that develop their own fields (for example, Russian corporations) have a significant competitive advantage. Also, competitive advantages for operators in the light petroleum products market are the geographical distribution of filling stations, the presence of a strong brand, additional service for consumers, and a significant number of loyal consumers. It was found that such factors as the presence of bureaucratic aspects in decision-making in cooperation with the state, unfair competition in the market from illegal gas stations, a gradual increase in the number of electric vehicles, global fluctuations in oil prices, legislative restrictions, inflation, potential devaluation of the hryvnia, as well as the low purchasing power of consumers have a threatening impact on the market. Among the weaknesses of the industry was the exhaustiveness of the planet's oil resources, and among the opportunities - the development of its own fields or the gradual diversification of production towards adjacent markets (for example, the renewable energy market). Based on the analysis of the light petroleum products industry, it was established that horizontal and vertical diversification strategies are promising for JSC "Concern Galnaftogaz". According to them, the main marketing solutions of this enterprise can be aimed at creating new types of products (in particular, related to renewable energy), building solar power plants and wind farms on the company's own land plots, and full access to the renewable energy market. The advantage of these strategies is the minimization of risk since the market is partially known (JSC "Concern Galnaftogaz" owns a façade solar power plant on the building of the head office and "green" filling stations (filling stations with solar panels on roofs) in areas with a high level of solar insolation. The implementation of the diversification strategy also consists in expanding the range of products offered by JSC "Concern Galnaftogaz", for example, by providing such a new service as testing fuel samples in mobile laboratories for individuals who would be able to carry out their own fuel quality check offered by various filling stations.

Precipitation barycenter and relationship to the spatial distribution of station networks on the Huang-Huai-Hai Plain, China

A precipitation barycenter reflects the overall spatial distribution and long-term evolution of regional precipitation. Understanding the changes in precipitation barycenter has significant implications for drought management, flood control, and water resource management. This paper analyzed the distribution and transfer of monthly, interannual, and interdecadal precipitation barycenter on the Huang-Huai-Hai Plain (‘3H’ Plain). We also discussed the influence of the station network spatial distribution on the changes in precipitation barycenter. The results were as follows: (1) The trajectory of the monthly precipitation barycenter on the ‘3H’ Plain was generally ‘8’-shaped. The rainy and dry season precipitation barycenters were located in the upper and lower parts of the ‘8’-shaped, respectively. (2) In the past 60 years, the interannual precipitation barycenter had a trend of moving southwest, but the trend was not apparent. (3) Station network density and uniformity dominated the changes in precipitation barycenter, showing positive correlations. When the station network density was large and exceeded a certain range, the influence of station network density on the changes in precipitation barycenter decreased.

Meteorological sub-divisions of India : Assessment of coherence, homogeneity and recommended redelineation

The data on mean rainfall and mean rainfall anomaly of the meteorological sub-divisions of India, on different time-scales, is extensively used for monitoring the progress of the monsoon as well as applications and research. As such, it is important to ensure that the sub-divisional means are meaningful representations of the rainfall and the rainfall anomaly at districts/stations within the sub-division. Hence, the criteria to be satisfied for an appropriate delineation of a meteorological sub-division are high levels of coherence and homogeneity. In this paper we present an assessment of the coherence and homogeneity of the current meteorological sub-divisions, for rainfall on the seasonal scale, by analysis of monthly district average rainfall for the period 1901-2015 during the summer monsoon for all the states, except Tamil Nadu for which June-December data are considered. Since, earlier studies have shown that some of the sub-divisions of Karnataka and Maharashtra are neither coherent nor homogeneous, the problem of redelineation of the sub-divisions of these states is first addressed. We have assumed that the number of coherent zones in a state is the same as the number of current sub-divisions. Identification of coherent zones is achieved by successive application of the K-means (KM) clustering method to the seasonal rainfall of the districts, considering correlation of seasonal rainfall between districts as a measure of similarity. For these two states we find that some of the districts are not coherent and homogeneous. So we have repeated the exercise with analysis of a dense station network. The coherent zones identified from analysis of district data as well as station data, are found to be homogeneous as well and we have recommended that they become the new sub-divisions of the states. The new sub-divisions suggested for Karnataka, which are coherent and homogeneous, are: (i) Karnataka Western coast and Ghats (which includes districts/stations in the current sub-division of Coastal Karnataka as well as some from the sub-divisions of interior Karnataka) (ii) Karnataka northern plateau and (iii) Karnataka southern plateau. Of the current sub-divisions of Maharashtra, Marathwada and Vidarbha satisfy the criteria of coherence and homogeneity and can be retained as such. The current Madhya Maharashtra sub-division does not satisfy the criteria of coherence and homogeneity. We have derived a modified version of Madhya Maharashtra by allocation of some districts/stations of Western Ghats from the existing sub-division of Madhya Maharashtra to the existing sub-division of Konkan and Goa to generate a modified version of Konkan and Goa. These modified versions are coherent and homogeneous. Thus the suggested sub-divisions of Maharashtra are (i) modified version of Konkan and Goa (which could have been renamed as Konkan, Ghats and Goa but we have retained the old name) and (ii) modified version of Madhya Maharashtra, along with the current sub-divisions of (iii) Marathwada and (iv) Vidarbha. We have shown that the sub-divisions of all the other states of mainland India, are homogeneous and reasonably coherent and recommend that they should be retained as such.

IoT-Based Sanitizer Station Network: A Facilities Management Case Study on Monitoring Hand Sanitizer Dispenser Usage

Maintaining hand hygiene has been an essential preventive measure for reducing disease transmission in public facilities, particularly during the COVID-19 pandemic. The large number of sanitizer stations deployed within public facilities, such as on university campuses, brings challenges for effective facility management. This paper proposes an IoT sensor network for tracking sanitizer usage in public facilities and supporting facility management using a data-driven approach. Specifically, the system integrates low-cost wireless sensors, LoRaWAN, and cloud-based computing techniques to realize data capture, communication, and analysis. The proposed approach was validated through field experiments in a large building on a university campus to assess the network signal coverage and effectiveness of sensor operation for facility monitoring. The results show that a LoRaWAN created from a single gateway can successfully connect to sensors distributed throughout the entire building, with the sensor nodes recording and transmitting events across the network for further analysis. Overall, this paper demonstrates the potential of leveraging the IoT-based Sanitizer Station Network to track public health mitigation methods in a large facility, which ultimately contributes to reducing the burden of maintaining public health during and post-pandemic.

The WegenerNet 3D Open-Air Laboratory for Climate Change Research: A unique facility for high-resolution precipitation studies

<p>The WegenerNet Feldbach Region is a unique weather and climate observation network comprising 155 hydrometeorological stations measuring temperature, humidity, precipitation, and at particular locations wind speed and direction as well as other parameters, in a tightly spaced grid within a core area of 22 km x 16 km centered near the city of Feldbach (46.93°N, 15.90°E), in southeastern Austria.</p><p>With about one station every two square-km (area of about 300 square-km in total), and each station with 5-min time sampling, the network provides fully automated regular measurements since January 2007.</p><p>In 2020, the station network was expanded by three major new components, expanding it from a 2D ground station hydrometeorological network into a 3D open-air laboratory for climate change research at very high resolution.  These new atmospheric 3D-observation components consist of:</p><p>1. A polarimetric X-band Doppler weather radar for studying precipitation parameters in the troposphere above the ground network, such as rain rate, hydrometeor classification, Doppler velocity, and approximate drop size distribution and number: it can provide 3D volume data (at about 1 km x 1 km horizontal and 500 m vertical resolution and 2.5 min time sampling) for moderate to strong precipitation. Together with the dense ground network, this allows detailed studies of heavy precipitation events with high resolution and accuracy.</p><p>2. A radiometer pair consisting of two azimuth- and elevation-steerable radiometers: (1) a microwave atmospheric-profiling radiometer with built-in auxiliary infrared radiometer for vertical profiling of temperature, humidity, and cloud liquid water in the troposphere above the WegenerNet area (with about 100 m to 1 km vertical resolution and 5 to 10 min time sampling), also capable of measuring cloud-base heights, vertically integrated water vapor (IWV), and slant IWV along line-of-sight paths towards Global Navigation Satellite System (GNSS) satellites, and (2) a complementary infrared cloud structure radiometer at similar spatiotemporal sampling for further refining gridded cloud-base height calculations and enabling multi-layer cloud-field reconstruction over the WegenerNet area, providing 3D cloud-field (multi-layered cloud fraction) estimates.</p><p>3. A water-vapor-mapping high-resolution GNSS station network named GNSS-StarNet, comprising six ground stations and spatially forming two star-shaped subnets across the WegenerNet area (one with about 10 km interstation distance and one embedded with about 5 km interstation distance), for providing slant IWV, vertical IWV, and precipitable water, among other parameters, at 2.5 to 15 min time sampling.</p><p>The new components, together with the existing ground network, provide a unique setup for studying extreme meteorological events such as heavy precipitation, hailstorms, droughts, and heat waves at very high resolution. We will present the up-to-date status of the WegenerNet and highlight recent uses in precipitation, hydrology and climate-related studies.</p>