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Sensors ◽  
2022 ◽  
Vol 22 (2) ◽  
pp. 472
Author(s):  
Abdullah Waqas ◽  
Nasir Saeed ◽  
Hasan Mahmood ◽  
Muhannad Almutiry

Fifth-generation and beyond networks target multiple distributed network application such as Internet of Things (IoT), connected robotics, and massive Machine Type Communication (mMTC). In the absence of a central management unit, the device need to search and establish a route towards the destination before initializing data transmission. In this paper, we proposes a destination search and routing method for distributed 5G and beyond networks. In the proposed method, the source node makes multiple attempts to search for a route towards the destination by expanding disk-like patterns originating from the source node. The source node increases the search area in each attempt, accommodating more nodes in the search process. As a result, the probability of finding the destination increases, which reduces energy consumption and time delay of routing. We propose three variants of routing for high, medium, and low-density network scenarios and analyze their performance for various network configurations. The results demonstrate that the performance of the proposed solution is better than previously proposed techniques in terms of time latency and reduced energy consumption, making it applicable for 5G and beyond networks.


Author(s):  
Jacqueline Jermyn

Abstract: Sampling-based path planners develop paths for robots to journey to their destinations. The two main types of sampling-based techniques are the probabilistic roadmap (PRM) and the Rapidly Exploring Random Tree (RRT). PRMs are multi-query methods that construct roadmaps to find routes, while RRTs are single-query techniques that grow search trees to find paths. This investigation evaluated the effectiveness of the PRM, the RRT, and the novel Hybrid RRT-PRM methods. This novel path planner was developed to improve the performance of the RRT and PRM techniques. It is a fusion of the RRT and PRM methods, and its goal is to reduce the path length. Experiments were conducted to evaluate the effectiveness of these path planners. The performance metrics included the path length, runtime, number of nodes in the path, number of nodes in the search tree or roadmap, and the number of iterations required to obtain the path. Results showed that the Hybrid RRT-PRM method was more effective than the PRM and RRT techniques because of the shorter path length. This new technique searched for a path in the convex hull region, which is a subset of the search area near to the start and end locations. The roadmap for the Hybrid RRT-PRM could also be re-used to find pathways for other sets of initial and final positions. Keywords: Path Planning, Sampling-based algorithms, search tree, roadmap, single-query planners, multi-query planners, Rapidly Exploring Random Tree (RRT), Probabilistic Roadmap (PRM), Hybrid RRT-PRM


Author(s):  
Xiuhua Hu ◽  
Huan Liu ◽  
Yuan Chen ◽  
Yan Hui ◽  
Yingyu Liang ◽  
...  

Aiming to solve the problem of tracking drift during movement, which was caused by the lack of discriminability of the feature information and the failure of a fixed template to adapt to the change of object appearance, the paper proposes an object tracking algorithm combining attention mechanism and correlation filter theory based on the framework of full convolutional Siamese neural networks. Firstly, the apparent information is processed by using the attention mechanism thought, where the object and search area features are optimized according to the spatial attention and channel attention module. At the same time, the cross-attention module is introduced to process the template branch and search area branch, respectively, which makes full use of the diversified context information of the search area. Then, the background perception correlation filter model with scale adaptation and learning rate adjustment is adopted into the model construction, using as a layer in the network model to realize the object template update. Finally, the optimal object location is determined according to the confidence map with similarity calculation. Experimental results show that the designed method in the paper can promote the object tracking performance under various challenging environments effectively; the success rate increases by 16.2%, and the accuracy rate increases by 16%.


Sensors ◽  
2021 ◽  
Vol 22 (1) ◽  
pp. 275
Author(s):  
Casper Bak Pedersen ◽  
Kasper Gaj Nielsen ◽  
Kasper Rosenkrands ◽  
Alex Elkjær Vasegaard ◽  
Peter Nielsen ◽  
...  

Search and Rescue (SAR) missions aim to search and provide first aid to persons in distress or danger. Due to the urgency of these situations, it is important to possess a system able to take fast action and effectively and efficiently utilise the available resources to conduct the mission. In addition, the potential complexity of the search such as the ruggedness of terrain or large size of the search region should be considered. Such issues can be tackled by using Unmanned Aerial Vehicles (UAVs) equipped with optical sensors. This can ensure the efficiency in terms of speed, coverage and flexibility required to conduct this type of time-sensitive missions. This paper centres on designing a fast solution approach for planning UAV-assisted SAR missions. The challenge is to cover an area where targets (people in distress after a hurricane or earthquake, lost vessels in sea, missing persons in mountainous area, etc.) can be potentially found with a variable likelihood. The search area is modelled using a scoring map to support the choice of the search sub-areas, where the scores represent the likelihood of finding a target. The goal of this paper is to propose a heuristic approach to automate the search process using scarce heterogeneous resources in the most efficient manner.


Author(s):  
Mohamed Ahmed Abou- Elnaga, Aml Mohamed Gomaa, Hamdi Mohamed Mohamed Ahmed Abou- Elnaga, Aml Mohamed Gomaa, Hamdi Mohamed

The research aimed to determine the level of farmers’ awareness about of agricultural environmental risks in new reclamation land association's in kalabshaw and zayan region, in dakahlia governorate by determining the level of farmers' awareness of causes of spread of agricultural environmental risks, as well as their awareness level of damage which caused by it, In addition to identify their awareness of spread rate agricultural environmental risks, and resulting damage from it, as well as the strengths, weaknesses, opportunities and challenges available to farmers to confront agricultural environmental risks in search area. The research was conducted on 337 farmers who were selected randomly and systematically from farmers of new reclamation landassociation's in kalabshaw and zayan region. Data were collected by using a questionnaire, pretest was done until it became valid for collected data during March and April 2021.  Morgan and Krejcie equation had been used to determine the sample size. Frequencies, percentages, rang, mean, standard deviation were used to present and analysis study data. The main results are as follows 1- More than two- fifths of farmers 42.4 % Their awareness level of reasons agricultural environmental risks spread was high.. 2- Two- fifths of farmers 40.7 % Their awareness level of awareness of damage which caused by agricultural environmental risks was high. 3- Two- fifths of farmers 40.4 % Their awareness level of diffusion rate agricultural environmental risks spread was high. 4- More than one- third of farmers 38.3 % Their awareness level of extent damage caused agricultural environmental risks spread was high 5- The most important aspects of strengths of farmers to face agricultural environmental risks were: Be careful to adjust dates of cultvited some crops, especially vegetables, to reduce sides effects of climate change 89%. 6- The most important aspects of weaknesses of farmers to face agricultural environmental risks were: Climate changes led to decrease productivity of some crops and increase food prices by 88.4%. 7- The most important aspects of opportunities of farmers to face agricultural environmental risks were: attuide towards to contract farming to prevent the exploitation of traders 89%. 8- The most important aspects of the challenges faced of farmers to face agricultural environmental risks were: The difficult economic conditions such as rise in land rent and rise prices of production requirements by 90.5%.


Mathematics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 83
Author(s):  
Sung-Won Cho ◽  
Jin-Hyoung Park ◽  
Hyun-Ji Park ◽  
Seongmin Kim

In the event of a maritime accident, surveying the maximum area efficiently in the least amount of time is crucial for rescuing survivors. Increasingly, unmanned aerial vehicles (UAVs) are being used in search and rescue operations. This study proposes a method to generate a search path that covers all generated nodes in the shortest amount of time with multiple heterogeneous UAVs. The proposed model, which is a mixed-integer linear programming (MILP) model based on a hexagonal grid-based decomposition method, was verified through a simulation analysis based on the performance of an actual UAV. This study presents both the optimization technique’s calculation time as a function of the search area size and the various UAV routes derived as the search area grows. The results of this study can have wide-ranging applications for emergency search and rescue operations.


2021 ◽  
Vol 16 (4) ◽  
pp. 435-444
Author(s):  
Ameer Mohammed Khalaf ◽  
Zuhair Jaber Mushref ◽  
Ismael Mohammed Khaleefah ◽  
Salah Othman Abed

Through the analysis of the digital elevation model (DEM) of the search area, it was found that the search area is located within a mountainous region with a complex twisting, as the surface has been classified into five regions of elevations, among which the first region represents the lowest elevation lands, and extends an area of 118.7 km2 It equates to (22.6%) of the total area, while the largest region is the second region, occupying an area of (187.9) km2, 36% of the total area of the region, while the regression categories were divided into five levels depending on the classification of (Zink) It turns out that the Fifth Region is the most complex of the regions, and it includes the summit of Mount Hendrin, the summit of Mount Karukh. As for the characteristics of the direction of the slopes, nine slope directions of varying areas were found. As for the density of vegetation coverage according to (NDVI), we find that the NDVI index in the research area is divided into three levels of plant density, as the second level, i.e. average density, recorded the largest area at about (344.8) km2, equivalent to (66.1%) of the area the college. Which is characterized by the topological complexity of the surface, which makes it the most suitable areas for pastoral activity, while the higher density in relation to vegetation coverage was more widespread in the first and second steep categories by about (2.5, 9.8) km2, i.e. (21.6%, 24.3%) of the total area.


Eos ◽  
2021 ◽  
Vol 102 ◽  
Author(s):  
Tim Hornyak

Researchers deploy geochemical analyses to narrow down the search area for a soil sample’s site of origin—an approach that could prove useful to law enforcement.


2021 ◽  
Author(s):  
Caroline Blocher ◽  
Filippo Pecci ◽  
Ivan Stoianov

Abstract Hydraulic model-based leak (burst) localisation in water networks is a challenging problem due to uncertainties, the limited number of hydraulic measurements, and the wide range of leak properties. In this study, we investigate the use of prior assumptions to improve the leak localisation in the presence of model uncertainties. For example, 𝓁2-regularisation relies on the assumption that the Euclidean norm of the leak coefficient vector should be minimised. This approach is compared with a method based on the sensitivity matrix, which assumes the existence of only a single leak. We show that while applying the sensitivity matrix often yields a better estimate of the leak location in single leak scenarios, the 𝓁2-regularisation successfully identifies a leak search area for pinpointing the accurate leak location. Furthermore, we demonstrate that the additional error introduced by a quadratic approximation of the Hazen-Williams formula for the solution of the localisation problem is negligible given the uncertainties in Hazen-Williams resistance coefficients in operational water network models.


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