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Author(s):  
Andres Valencia Acuña ◽  
◽  
Brian Meneses Claudio ◽  
Alexi Delgado

In recent years being able to have access to the internet has become a tool not only to be able to communicate in the distance but it is a great tool to be able to feed knowledge, it is because of them that children have a great educational utility and after this pandemic in Peru it was necessary to close schools, to be able to give remote classes or virtual classes. To solve the problem, we propose to be able to design a network of radio links whereby means of a base station of emission and reception, with an antenna of sectorial type and directional antennas to be able to realize a Point – Multipoint link which will be able to manage the quality of signal by means of a routing with functions of control of speeds for each connection of each home. It was the result that the connections of the radio link at an average distance from the coverage that the network had the signal was better and that the connections that were very far or close to the coverage area had complications, but despite this the connections were sufficient to be able to maintain the virtual classes that is what was planned. It is recommended that for a better connection and complete coverage it would be to reinforce the broadcast base with more sectoral antennas in the network. Keywords- Radio link, Point - Multipoint, Router, Download speed, Upload speed.


Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 612
Author(s):  
Răzvan-George Bărtuşică ◽  
Mădălin Mihai ◽  
Simona Halunga ◽  
Octavian Fratu

This paper presents a technical solution that addresses mission-critical communications by extending the radio frequency coverage area using a flexible and scalable architecture. One of the main objectives is to improve both the reaction time and the coordination between mission-critical practitioners, also called public protection and disaster relief users, that operate in emergency scenarios. Mission-critical services such as voice and data should benefit from reliable communication systems that offer high availability, prioritization and flexible architecture. In this paper, we considered Terrestrial Trunked Radio (TETRA), the mobile radio standard used for mission-critical communications, as it has been designed in this respect and is widely used by first responder organizations. Even if RF coverage is designed before network deployment and continuously updated during the lifetime of the technology, some white areas may exist and should be covered by supplementary base stations or repeaters. The model presented in this paper is an optical repeater for TETRA standard that can offer up to 52.6 dB downlink, 65.6 dB uplink gain and up to 3.71 km coverage distance in a radiating cable installation scenario. The design in not limited, as it can be extended to several different mobile radio standards using the same principle. Flexibility and scalability attributes are taken into consideration, as they can build a cost-effective deployment considering both capital and operational expenditures.


Land ◽  
2022 ◽  
Vol 11 (1) ◽  
pp. 104
Author(s):  
Lei Li ◽  
Chenzi Pan ◽  
Shuai Ling ◽  
Mingqi Li

Industrial land is an indispensable strategic resource in urban development that plays an indispensable role in ensuring the industrial space of urban construction and development. Measuring and analyzing the eco-efficiency of industrial land utilization (ECILU) can provide insights into how to maximize the input–output ratio of industrial land and ensure the sustainable development of land resources and economies. Based on the undesirable output slacks-based measure (SBM) model, choosing land, capital, and labor as input indicators, and the industrial added value and carbon emissions as desirable and undesirable output indicators, this study measured the ECILUs in 78 cities and 13 metropolitan areas in four Chinese major economic zones from 2007 to 2018, analyzed their spatial and temporal evolution characteristics and regional differences, and constructed a Tobit regression model to test the influence mechanism of each variable on the ECILUs in different regions. This has important theoretical and practical significance for the Chinese government in formulating relevant policies and realizing the green utilization of urban land in the future. Empirical results showed that the ECILUs in most cities were low and that the differences between regions were large. The ECILU in the Western Economic Zone was relatively high, followed by the Eastern, Central, and Northeastern Economic Zones. According to the ECILU value and urban synergy degree of each metropolitan area, this study divided the 13 metropolitan areas into four categories. The regression analysis results showed that the variables had different effects on the ECILUs of all cities and the four economic zones in China. It is suggested that all economic zones should reinforce the optimization of industrial structure, control industrial pollutant discharge, and solve the phenomenon of labor surplus. The Eastern Zone should maintain the growth of its economy while focusing on soil quality. The Central Zone should focus on the efficient use of infrastructure, and the Western, Northeastern, and Central Zones should balance the green coverage area and the industrial land area to ensure the efficient use of urban industrial land.


2022 ◽  
pp. 073168442110666
Author(s):  
Biruk F Nega ◽  
Robert S Pierce ◽  
Linlin Liu ◽  
Xiaosu Yi ◽  
Xiaoling Liu

This work investigates the effect of preform compaction on the mechanical performance and flow-induced fibre alignment of carbon fibre reinforced Sheet Moulding Compounds (SMCs). Two groups of panels have been compression moulded from reclaimed carbon fibre tows in vinyl-ester resin with low (0.5 MPa) and high (10 MPa) preform compaction pressure Additionally, a low-cost fibre orientation analysis method has been further improved in terms of reliability, and a novel flow assessment method has been developed for carbon fibre SMCs. This approach revealed greater fibre alignment with the flow direction in the lower faces of panels as a result of greater contact time with the heated mould and a lower charge viscosity at the time of pressing. As expected, greater fibre alignment in the flow direction was observed outside the initial charge coverage area in both types of panels, where the flow was greatest. Due to additional fibre flow during the high-pressure compaction stage, the mean degree of flow alignment in the high compaction panel was 47% higher than that of the low compaction panel. Improvements in the tensile stiffness (8%) and strength (32%) were also observed as a result of the high-pressure compaction stage and associated flow alignment.


2022 ◽  
pp. 529-550
Author(s):  
Elias Yaacoub

The chapter investigates the scheduling load added on a long-term evolution (LTE) and/or LTE-Advanced (LTEA) network when automatic meter reading (AMR) in advanced metering infrastructures (AMI) is performed using internet of things (IoT) deployments of smart meters in the smart grid. First, radio resource management algorithms to perform dynamic scheduling of the meter transmissions are proposed and shown to allow the accommodation of a large number of smart meters within a limited coverage area. Then, potential techniques for reducing the signaling load between the meters and base stations are proposed and analyzed. Afterwards, advanced concepts from LTE-A, namely carrier aggregation (CA) and relay stations (RSs) are investigated in conjunction with the proposed algorithms in order to accommodate a larger number of smart meters without disturbing cellular communications.


Atmosphere ◽  
2021 ◽  
Vol 13 (1) ◽  
pp. 61
Author(s):  
Nan-Ching Yeh ◽  
Yao-Chung Chuang ◽  
Hsin-Shuo Peng ◽  
Chih-Ying Chen

In Taiwan, the frequency of afternoon convection increases in summer (July and August), and the peak hour of afternoon convection occurs at 1500–1600 local solar time (LST). Afternoon convection events are forecasted based on the atmospheric stability index, as computed from the 0800 LST radiosonde data. However, the temporal and spatial resolution and forecast precision are not satisfactory. This study used the observation data of Aqua satellite overpass near Taiwan around 1–3 h before the occurrence of afternoon convection. Its advantages are that it improves the prediction accuracy and increases the data coverage area, which means that more airports can use results of this research, especially those without radiosondes. In order to determine the availability of Atmospheric Infrared Sounder (AIRS) in Taiwan, 2010–2016 AIRS and radiosonde-sounding data were used to determine the accuracy of AIRS. This study also used 2017–2018 AIRS data to establish K index (KI) and total precipitable water (TPW) thresholds for the occurrence of afternoon convection of four airports in Taiwan. Finally, the KI and TPW were calculated using the independent AIRS atmospheric sounding (2019–2020) to forecast the occurrence of afternoon convection at each airport. The average predictive accuracy rate of the four airports is 84%. Case studies at Hualien Airport show the average predictive accuracy rate of this study is 81.8%, which is 9.1% higher than that of the traditional sounding forecast (72.7%) during the same period. Research results show that using AIRS data to predict afternoon convection in this study could not only increase data coverage area but also improve the accuracy of the prediction effectively.


Author(s):  
Nayan S. Jambhulkar ◽  
◽  
Dr. Shailesh Kumar ◽  
Dr. Krushnadeo T. Belerao ◽  
◽  
...  

Now a days for the radio network communication multi-hop routing is used. This multi-hop routing technique covers larger coverage area. Therefore to reach at specific location data is transferred in form of packets from one node to other node. But for the transmission of radio signals over the large distance, large number of transreceivers are required and these transreceivers requires large power to operate. As a result, multi-hop routing can saves energy over separate routing. Therefore it is necessity to design a cost effective multi-hop routing technique for successful transmission of ratio packet data. In this paper a hop by hop adaptive link state optional routing (HALO) is explained. It is the first packet transmitting solution with hop by hop and link state routing, which reduces the cost of transporting data across a packet switch network[3]. The triple model is designed for multi hop packet routing. In this work each node of network iteratively and separately improves the small part of traffic bound. This algorithm finds the shortest path of specific location for every iteration and it is calculated by the marginal cost of the various links of network. The marginal link cost is used to calculate the shortest path between the node and the destination location. This marginal link cost is gathered from link state updates. The various networks changes are automatically identified by the adaptive method which is used in this paper. Due to this the exchange between the packets on wrong node is reduced over the overhead traffic. To validate these theoretical results the experimental evaluations and mathematical calculations are also reported in this work. Net beans java is the programmed use in this proposed project.


MAUSAM ◽  
2021 ◽  
Vol 65 (4) ◽  
Author(s):  
LI LEI ◽  
ZHANG LIJIE ◽  
ZHANG XIAOLI ◽  
LU CHAO ◽  
ZHANG LI ◽  
...  

Based on the air temperature data collected from automated weather stations, the urban heat island (UHI) intensity in Shenzhen metropolis is calculated and the impact of several factors, including land-sea distribution, population density, road coverage area and power load, on the UHI intensity are analyzed. The analysis shows that the land-sea distribution is the dominant factor for the UHI distribution in Shenzhen, with the climate-adjusting effect of the sea clearly reducing the UHI intensity in the east and west parts of Shenzhen. The middle part of Shenzhen is adjacent to Hong Kong and the climate-adjusting effect of the sea is weak, which leads to UHI intensity being centered around this area. The population density and road coverage area do impact the UHI in Shenzhen, with strong dependency between the UHI intensity and the two factors (p < 0.01). However, in the area with the densest roads, the UHI intensity is not high, which may be related to the high yearly-average wind speed in this area. Comparing the data from 2011 and 2010 shows strong impact of the power load on the UHI intensity in Shenzhen, and the increase of the UHI intensity in 2011 is highly likely to be due to the increase of the power load in the colder winter and the hotter summer of 2011.


2021 ◽  
Vol 14 (1) ◽  
pp. 104 ◽  
Author(s):  
Zhanjie Wang ◽  
Jianghua Zhao ◽  
Ran Zhang ◽  
Zheng Li ◽  
Qinghui Lin ◽  
...  

Cloud recognition is a basic task in ground meteorological observation. It is of great significance to accurately identify cloud types from long-time-series satellite cloud images for improving the reliability and accuracy of weather forecasting. However, different from ground-based cloud images with a small observation range and easy operation, satellite cloud images have a wider cloud coverage area and contain more surface features. Hence, it is difficult to effectively extract the structural shape, area size, contour shape, hue, shadow and texture of clouds through traditional deep learning methods. In order to analyze the regional cloud type characteristics effectively, we construct a China region meteorological satellite cloud image dataset named CRMSCD, which consists of nine cloud types and the clear sky (cloudless). In this paper, we propose a novel neural network model, UATNet, which can realize the pixel-level classification of meteorological satellite cloud images. Our model efficiently integrates the spatial and multi-channel information of clouds. Specifically, several transformer blocks with modified self-attention computation (swin transformer blocks) and patch merging operations are used to build a hierarchical transformer, and spatial displacement is introduced to construct long-distance cross-window connections. In addition, we introduce a Channel Cross fusion with Transformer (CCT) to guide the multi-scale channel fusion, and design an Attention-based Squeeze and Excitation (ASE) to effectively connect the fused multi-scale channel information to the decoder features. The experimental results demonstrate that the proposed model achieved 82.33% PA, 67.79% MPA, 54.51% MIoU and 70.96% FWIoU on CRMSCD. Compared with the existing models, our method produces more precise segmentation performance, which demonstrates its superiority on meteorological satellite cloud recognition tasks.


2021 ◽  
Vol 14 (1) ◽  
pp. 100
Author(s):  
Siddhartha Khare ◽  
Annie Deslauriers ◽  
Hubert Morin ◽  
Hooman Latifi ◽  
Sergio Rossi

Intercomparison of satellite-derived vegetation phenology is scarce in remote locations because of the limited coverage area and low temporal resolution of field observations. By their reliable near-ground observations and high-frequency data collection, PhenoCams can be a robust tool for intercomparison of land surface phenology derived from satellites. This study aims to investigate the transition dates of black spruce (Picea mariana (Mill.) B.S.P.) phenology by comparing fortnightly the MODIS normalized difference vegetation index (NDVI) and the enhanced vegetation index (EVI) extracted using the Google Earth Engine (GEE) platform with the daily PhenoCam-based green chromatic coordinate (GCC) index. Data were collected from 2016 to 2019 by PhenoCams installed in six mature stands along a latitudinal gradient of the boreal forests of Quebec, Canada. All time series were fitted by double-logistic functions, and the estimated parameters were compared between NDVI, EVI, and GCC. The onset of GCC occurred in the second week of May, whereas the ending of GCC occurred in the last week of September. We demonstrated that GCC was more correlated with EVI (R2 from 0.66 to 0.85) than NDVI (R2 from 0.52 to 0.68). In addition, the onset and ending of phenology were shown to differ by 3.5 and 5.4 days between EVI and GCC, respectively. Larger differences were detected between NDVI and GCC, 17.05 and 26.89 days for the onset and ending, respectively. EVI showed better estimations of the phenological dates than NDVI. This better performance is explained by the higher spectral sensitivity of EVI for multiple canopy leaf layers due to the presence of an additional blue band and an optimized soil factor value. Our study demonstrates that the phenological observations derived from PhenoCam are comparable with the EVI index. We conclude that EVI is more suitable than NDVI to assess phenology in evergreen species of the northern boreal region, where PhenoCam data are not available. The EVI index could be used as a reliable proxy of GCC for monitoring evergreen species phenology in areas with reduced access, or where repeated data collection from remote areas are logistically difficult due to the extreme weather.


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