Journal articles: 'Area Coverage Control'

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Phuphanin, Akkhachai, and Wipawee Usaha. "Scalarized Q Multi-Objective Reinforcement Learning for Area Coverage Control and Light Control Implementation." ECTI Transactions on Electrical Engineering, Electronics, and Communications 16, no. 2 (April 3, 2018): 72–82. http://dx.doi.org/10.37936/ecti-eec.2018162.171333.

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Coverage control is crucial for the deployment of wireless sensor networks (WSNs). However, most coverage control schemes are based on single objective optimization such as coverage area only, which do not consider other contradicting objectives such as energy consumption, the number of working nodes, wasteful overlapping areas. This paper proposes on a Multi-Objective Optimization (MOO) coverage control called Scalarized Q Multi-Objective Reinforcement Learning (SQMORL). The two objectives are to achieve the maximize area coverage and to minimize the overlapping area to reduce energy consumption. Performance evaluation is conducted for both simulation and multi-agent lighting control testbed experiments. Simulation results show that SQMORL can obtain more efficient area coverage with fewer working nodes than other existing schemes. The hardware testbed results show that SQMORL algorithm can find the optimal policy with good accuracy from the repeated runs.

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Papatheodorou, Sotiris, Anthony Tzes, Konstantinos Giannousakis, and Yiannis Stergiopoulos. "Distributed area coverage control with imprecise robot localization." International Journal of Advanced Robotic Systems 15, no. 5 (September 1, 2018): 172988141879749. http://dx.doi.org/10.1177/1729881418797494.

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This article examines the static area coverage problem by a network of mobile, sensor-equipped agents with imprecise localization. Each agent has uniform radial sensing ability and is governed by first-order kinodynamics. To partition the region of interest, a novel partitioning scheme, the Additively Weighted Guaranteed Voronoi diagram is introduced which takes into account both the agents’ positioning uncertainty and their heterogeneous sensing performance. Each agent’s region of responsibility corresponds to its Additively Weighted Guaranteed Voronoi cell, bounded by hyperbolic arcs. An appropriate gradient ascent-based control scheme is derived so that it guarantees monotonic increase of a coverage objective and is extended with collision avoidance properties. Additionally, a computationally efficient simplified control scheme is offered that is able to achieve comparable performance. Several simulation studies are offered to evaluate the performance of the two control schemes. Finally, two experiments using small differential drive-like robots and an ultra-wideband positioning system were conducted, highlighting the performance of the proposed control scheme in a real world scenario.

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Papatheodorou, Sotiris, and Anthony Tzes. "Fault tolerant area coverage control for multiagent systems." MATEC Web of Conferences 188 (2018): 05010. http://dx.doi.org/10.1051/matecconf/201818805010.

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The fault tolerance characteristics of a distributed multi-agent coverage algorithm are examined. A team of sensor-equipped mobile agents is tasked with covering a planar region of interest. A distributed, gradient-based control scheme is utilized for this purpose. The agents are assumed to consist of three subsystems, each one of which may fail. The subsystems under examination are the actuation, sensing and the communication subsystem. Partial and catastrophic faults are examined. Several simulation studies are conducted highlighting the robustness of the distributed nature of the control scheme to these classes of faults, even when several of them happen at the same time.

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Ibrahim, M., J. Matschek, B. Morabito, and R. Findeisen. "Hierarchical Model Predictive Control for Autonomous Vehicle Area Coverage." IFAC-PapersOnLine 52, no. 12 (2019): 79–84. http://dx.doi.org/10.1016/j.ifacol.2019.11.073.

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Zheng, Zhi, and Zhihong Peng. "Distributed Cooperation Based Priority Coverage Control Strategy for Mobile Sensors." Journal of Advanced Computational Intelligence and Intelligent Informatics 19, no. 2 (March 20, 2015): 191–96. http://dx.doi.org/10.20965/jaciii.2015.p0191.

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Random deployment and inadequate numbers of sensor nodes may cause low coverage, so we propose a new priority coverage control strategy based on the distributed cooperation of mobile sensors. Sensor nodes are distributed randomly around the region of interest (ROI) and searched for independently. When nodes are found, an unbreakable group is formed under repulsion, attraction and speed consistency control, then searching is begun cooperatively. When some node finds a ROI, it guides the other nodes in the group following it to the ROI. While in the ROI, nodes choose the most important position within the sensing range, then move toward it independently while avoiding collision, eventually, reaching the most important area of the ROI. Under the premise of satisfying key area coverage, sensor nodes are adjusted based on the degree of coverage, maximizing coverage. Simulation results show that the proposed method quickly improves the coverage rate and achieves priority coverage of key areas strongly robustly without being adversely affected by sudden damage to nodes. Applications include coverage with limited amounts of nodes in unknown environments.

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Shi, Mengji, and Kaiyu Qin. "Distributed Control of Networked Unmanned Aerial Vehicles for Valley Area Coverage." Mobile Information Systems 2016 (2016): 1–12. http://dx.doi.org/10.1155/2016/3680265.

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The paper provides a novel cooperative motion scheme for networked Unmanned Aerial Vehicles (UAVs) to fully sweep-cover a priori unknown elongated areas with curved borders, which are termed “valley areas.” The UAVs’ motion is confined between the borders. Different from former research on straight-corridor-sweep-coverage, in each valley area, the width of different portions varies dramatically: the UAVs need to line up across the valley area to achieve full coverage of the widest portions while they can only pass through the narrowest parts one by one in a queue. The UAVs are provided with barrier detection and inter-UAV communication. According to the scheme, a distributed control law has been offered for discrete-time multi-UAV systems, guaranteeing crash avoidance and full coverage while considering the constrained mobility of the UAVs. Regular and extreme simulations are carried out to verify the efficacy and stability of the proposed algorithm. Solutions to U-shaped valley coverage and the case of insufficient UAVs available are discussed with validation simulations. Comparison simulations are conducted with respect to a line-sweep-coverage algorithm developed by a closely related work, and differences in performance are revealed subsequently. Conclusions are drawn with possible directions of future research.

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Agarwal, Saurav, and Srinivas Akella. "Area Coverage With Multiple Capacity-Constrained Robots." IEEE Robotics and Automation Letters 7, no. 2 (April 2022): 3734–41. http://dx.doi.org/10.1109/lra.2022.3146952.

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Munawar, Hafiz Suliman, Ahmed W. A. Hammad, and S. Travis Waller. "Disaster Region Coverage Using Drones: Maximum Area Coverage and Minimum Resource Utilisation." Drones 6, no. 4 (April 13, 2022): 96. http://dx.doi.org/10.3390/drones6040096.

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The purpose of this study is to develop a design for maximum area drone coverage in a post-disaster flood situation. When it comes to covering a disaster-region for monitoring and detection of the extent of damage and losses, a suitable and technically balanced approach is vital to achieving the best solution while covering the maximum affected area. Therefore, a mathematical optimisation model is proposed to effectively capture maximum images of the impacted region. The particle swarm optimisation (PSO) algorithm is used to solve the optimisation problem. Modern relief missions heavily rely on drones, specifically in the case of flooding, to capture the damage due to the disaster and to create roadmaps to help impacted people. This system has convincing results for inertia, exploration, exploitation, velocity, and determining the height of the drones to enhance the response to a disaster. The proposed approach indicates that when maintaining the flight height of the drone above 120 m, the coverage can be enhanced by approximately 34% compared with a flight height of 100 m.

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An, Wei, Fang-Ming Shao, and Huajun Meng. "The coverage-control optimization in sensor network subject to sensing area." Computers & Mathematics with Applications 57, no. 4 (February 2009): 529–39. http://dx.doi.org/10.1016/j.camwa.2008.10.095.

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Behairy, Hatim, Waleed Alrobian, Adnan Alghammas, Amr Alasaad, Brian Suter, Mohammed Alshareef, and Yahya Alsuwayyeh. "Selective Mobile Communication within a Coverage Area Bounded by Radiating Cables." Mobile Information Systems 2015 (2015): 1–9. http://dx.doi.org/10.1155/2015/138067.

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It is often desirable to control mobile phone services in areas where complete silence is either expected or mandatory, including schools, places of worship, hospitals, and prisons. In contrast to conventional techniques, such as jammers or Faraday cages, we present a novel technique to selectively control mobile phone services within a desired area. Our solution enables the area’s keeper to allow mobile phones on a whitelist to freely use mobile services without disruption while denying services to all other mobile phones that are within the boundaries of the desired area to be controlled. Our solution uses a base station controller to identify all mobile devices located within the area to be controlled, while an antenna is placed inside the area to attract all mobile devices in the area to connect to the base station controller. In previous work, we proposed a system that uses directional antennas for the attraction technique. In this work, we show that replacement of the directional antennas with a leaky feeder antenna enables more accurate control of mobile phone services in and around the area to be controlled. Simulations and experiments of the leaky feeder technique confirm its precise control of mobile phone services within the desired areas.

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Zhang, Ziyong, Xiaoling Xu, Jinqiang Cui, and Wei Meng. "Multi-UAV Area Coverage Based on Relative Localization: Algorithms and Optimal UAV Placement." Sensors 21, no. 7 (March 31, 2021): 2400. http://dx.doi.org/10.3390/s21072400.

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This paper is concerned with relative localization-based optimal area coverage placement using multiple unmanned aerial vehicles (UAVs). It is assumed that only one of the UAVs has its global position information before performing the area coverage task and that ranging measurements can be obtained among the UAVs by using ultra-wide band (UWB) sensors. In this case, multi-UAV relative localization and cooperative coverage control have to be run simultaneously, which is a quite challenging task. In this paper, we propose a single-landmark-based relative localization algorithm, combined with a distributed coverage control law. At the same time, the optimal multi-UAV placement problem was formulated as a quadratic programming problem by compromising between optimal relative localization and optimal coverage control and was solved by using Sequential Quadratic Programming (SQP) algorithms. Simulation results show that our proposed method can guarantee that a team of UAVs can efficiently localize themselves in a cooperative manner and, at the same time, complete the area coverage task.

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Valent, Francesca, and Annarita Tullio. "Glycaemic control, antidiabetic medications and influenza vaccination coverage among patients with diabetes in Udine, Italy." Family Medicine and Community Health 7, no. 3 (September 2019): e000198. http://dx.doi.org/10.1136/fmch-2019-000198.

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ObjectiveThe objectives of this study were to estimate influenza vaccination coverage among patients with diabetes mellitus in an Italian 250 000-inhabitant area in the 2017–2018 season and to assess whether glycaemic control and pharmacological treatment were associated with the likelihood of being vaccinated.DesignIn this cross-sectional study, we analysed anonymous health administrative databases, linked with each other at the individual patient level through a stochastic key: diabetes mellitus registry, vaccinations, drug prescriptions and laboratory database.SettingThe study was conducted in the catchment area of the University Hospital of Udine (‘the Udine area’), a 250 000-inhabitant area in the northeast of Italy.ParticipantsThe study included all subjects included in the regional registry of patients with diabetes mellitus, living in the Udine area as of 1 October 2017.Main outcome measuresVaccination coverage in the 2017–2018 influenza season was calculated. The association between patients’ characteristics and the likelihood of being vaccinated was assessed through multivariate log binomial regression.Result53.0% of 15 900 patients with diabetes living in the area were vaccinated. Coverage increased with age, approaching 75% at ≥85 years. Patients lacking recent glycated haemoglobin testing were less likely to be vaccinated (43.4% vaccination coverage), as were those not treated pharmacologically (44.4% vaccination coverage). Patients treated with both insulin, metformin and other antidiabetic medications were more likely to be vaccinated than those treated with metformin alone (58.1% vaccination coverage; adjusted relative risk=1.07, 95% CI 1.01 to 1.14).ConclusionInfluenza vaccination coverage was suboptimal in this Italian population of patients with diabetes. Strategies to improve diabetes management could in turn positively affect influenza coverage.

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Huang, Sunan, Rodney Swee Huat Teo, William Wai Lun Leong, Niki Martinel, Gian Luca Forest, and Christian Micheloni. "Coverage Control of Multiple Unmanned Aerial Vehicles: A Short Review." Unmanned Systems 06, no. 02 (April 2018): 131–44. http://dx.doi.org/10.1142/s2301385018400046.

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A multiple unmanned aerial vehicle (MUAV) system is a group of vehicles that are designed with the aim to perform some collective behavior. Coverage control is one of the most active research fields in MUAVs. As MUAVs are nowadays widely used in many application areas, the research in the coverage control problem has become a hot point. Although several coverage control methods have been reported, there is a lack of work highlighting the features of these methods. In this paper, we present a survey of the most relevant works in this area, classifying the types of these works and describing the main contributions in their works.

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Sfendourakis, Marios, Alexios Staridas, Iason Dimou, Alexia Dima, Theodore ,. Papadoulis, Lambros Frantzeskakis, Zisis Makris, and Rajagopal Nilavalan. "Area Coverage improvement of a Fixed Sensors Network System using Fuzzy Control." WSEAS TRANSACTIONS ON SYSTEMS AND CONTROL 17 (August 3, 2022): 347–58. http://dx.doi.org/10.37394/23203.2022.17.39.

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This paper presents a novel work on localization of transmitters using triangulation with sensors at fixed positions. This is achieved when three or more sensors cover the whole area, a factor which enables the system to perform localization via triangulation. The network needs to keep a high detection rate which, in most cases, is achieved by adequate sensor coverage. Various tests using various grids of sensors have been carried out to investigate the way the system operates in different cases using a lot of transmitters. Detection complexity is tackled by finding the optimal detecting sensor radius in order for the network to continue operate normally. The coverage quality changes in the area of interest and the network is able to detect new transmitters that might enter the area of interest. It is also shown that as the number of transmitters increases the network keeps its high performance by using additional groups of sensors in a sub-region area of that of interest. This way, even when the network is saturated by many transmitters in one region, new transmitters can still be detected.

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Darmaraju, Shalini, Madhavan Shanmugavel, Md Abdus Samad Kamal, and Chee Pin Tan. "Area Coverage by a Group of UAVs using the Broadcast Control Framework." IFAC-PapersOnLine 52, no. 12 (2019): 370–75. http://dx.doi.org/10.1016/j.ifacol.2019.11.271.

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Ramar, Ramalakshmi, and Radhakrishnan Shanmugasundaram. "Connected k-Coverage Topology Control for Area Monitoring in Wireless Sensor Networks." Wireless Personal Communications 84, no. 2 (May 17, 2015): 1051–67. http://dx.doi.org/10.1007/s11277-015-2675-9.

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Behrens, Andrew, Kevin N. Dibbern, Nacime SB Mansur, Amanda Ehret, Nathan Chen, Hannah J. Stebral, Francois Lintz, et al. "Chopart Peritalar Subluxation in Progressive Collapsing Foot Deformity Assessed by Three- Dimensional Coverage Maps." Foot & Ankle Orthopaedics 7, no. 4 (October 2022): 2473011421S0058. http://dx.doi.org/10.1177/2473011421s00580.

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Category: Hindfoot; Midfoot/Forefoot; Other Introduction/Purpose: Progressive collapsing foot deformity (PCFD) is a complex three-dimensional (3D) deformity characterized by peritalar subluxation (PTS) of the hindfoot through the triple joint complex. In this context, adjacent structures adopt different positions, and bone relations change, producing areas of higher or less contact and stress. The objective of this study was to use 3D distance maps (DMs) and coverage maps (CMs) from weightbearing CT (WBCT) images to assess subluxation across the Chopart joint in PCFD patients. We hypothesized that CMs would show decreased coverage indicative of subluxation through regions of the Chopart joint in PCFD patients when compared to controls. Methods: In this IRB-approved, retrospective case-control study, we analyzed WBCT data of 20 consecutive patients with flexible PCFD and 20 controls. Using principle component analysis, coverage area was divided into six regions on the talar head and 4 on the calcaneal-cuboid articular surface. Novel 3D distance mapping (DM) technique was used to objectively characterize joint coverage across the entire Chopart surface on both talus and calcaneus. Distance maps were measured in millimeters and colored to highlight covered areas. Distances less than 4mm were defined to be covered, while areas with distances greater than 4mm uncovered. Joint coverage was defined as percentage of articular area with DMs lower than 4 mm. Coverage Maps (CM) were built highlighting areas of coverage (teal) versus non-coverage (pink). The Foot and Ankle Offset (FAO) was used as a reference semi-automatic three-dimensional measurement. Comparisons were performed with independent t-tests, assuming unequal variances and p-values <.05 considered significant. Results: Changes in coverage percentages of PCFD cases relative to controls are indicated in the attached figure. The superomedial and the inferomedial regions of the talar head were found to have a 75% and 79% decrease in coverage in PCFD cases relative to the controls (ps<0.003). The medial side of the head had an overall increase in coverage (ps<0.002). On the calcaneus, the calcaneal-cuboid joint plantar region was found to have a significant coverage decrease of 12% relative to the controls (p=0.037), while the lateral quadrant observed a 13% increase (p=0.002). DMs evaluation showed no significant differences in the mean distances for either the calcaneocuboid or the talonavicular (ps>0.05). The FAO was found to be correlated with changes in talar and calcaneal coverages (rs=0.90; R2=0.81). Conclusion: Our results support the hypothesis that significant changes occur at the Chopart joint in early flexible PCFD cases. Increased coverage in the lateral region of the talar head and decreased coverage in the medial and plantar regions point to internal rotation of the talus indicating subluxation through the entire joint. This behavior was also translated in the calcaneal- cuboid, where plantar and medial areas had a decrease in coverage. Coverage 3D mapping enabled objective subluxation quantification through the Chopart joint in early-stage PCFD. These findings may assist clinical assessment of normal joint alignment restoration during PCFD corrections.

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Sun, Zeyu, Rong Tao, Longxing Li, and Xiaofei Xing. "A New Energy-efficient Multi-target Coverage Control Protocol Using Event-driven-mechanism in Wireless Sensor Networks." International Journal of Online Engineering (iJOE) 13, no. 02 (February 27, 2017): 53. http://dx.doi.org/10.3991/ijoe.v13i02.6465.

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The covering problem and node deployment is a fundamental problem in the research into wireless sensor networks. The number of nodes and the coverage of a network can directly affect performance and operating costs. For this reason, we propose Event-driven-mechanism Coverage Control Protocol (ECCP). The algorithm uses the correlation between the nodes and dynamic grouping to adjust the coverage area. Within the coverage area, we use the greedy algorithm to optimize the coverage area. So the target node is uniformly covered by other sensor nodes and the network resource is optimized. To ensure the energy balance in the wireless sensor network and extend its lifetime, we only wake partial nodes to work in a cycle, so that they can work in turn. Experiments show that the algorithm can effectively reduce energy consumption, with better adaptability and effectiveness.

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Li, Qiangyi, and Ningzhong Liu. "Monitoring Area Coverage Based on Control Multimedia Nodes Position in Mixed Underwater Mobile Wireless Sensor Networks." Advances in Multimedia 2022 (September 28, 2022): 1–10. http://dx.doi.org/10.1155/2022/5888728.

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Due to the high cost of mobile nodes and the low cost of fixed nodes, in some applications of wireless sensor networks, in order to reduce the use cost, the mixed mode is used for node deployment. The deployed nodes include both fixed and mobile nodes. After the nodes are deployed, the fixed nodes do not move, and the mobile nodes move reasonably according to the network coverage to improve the network coverage effect. Due to the differences in equipment structure and use cost between fixed nodes and mobile nodes, in order to complete the monitoring task under the condition of reducing the use cost of wireless sensor networks, the number and position of mobile nodes can be reasonably adjusted as needed to improve the effective coverage area of wireless sensor networks. In the process of adjusting the position of mobile nodes, the moving distance of mobile nodes is fully considered. Simulation results show that this algorithm can improve the coverage effect of mixed wireless sensor networks and reduce the moving distance of mobile nodes.

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Lee, Jae-Yong, and Nam-Sun Son. "On the Estimation of the Mission Performance Index of Unmanned Surface Vehicles Based on the Mission Coverage Area." Advances in Technology Innovation 8, no. 1 (January 1, 2023): 29–37. http://dx.doi.org/10.46604/aiti.2023.10548.

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For mission planning and replanning of multiple unmanned surface vehicles (USVs), it is important to estimate each USV’s mission performance in terms of sea surveillance (e.g., illegal ship control). In this study, a mission performance index (MPI) is proposed based on the mission coverage area for estimating the USVs’ mission performance of illegal ship control. The penalty value is considered in the MPI calculation procedure owing to the track-off of the USV. In addition, the USV simulation is conducted under illegal ship control, and the MPI is calculated based on changing the mission coverage area. The results show that the MPI increases with the path width of the mission coverage area.

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Olcay, Ertug, and Yixing Zhai. "Spontaneous Area Coverage and Mapping of Restricted Zones with Multiple Mobile Agents." IFAC-PapersOnLine 55, no. 13 (2022): 240–45. http://dx.doi.org/10.1016/j.ifacol.2022.07.266.

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Samarakoon, S. M. Bhagya P., M. A. Viraj J. Muthugala, Raihan E. Abdulkader, Soh Wei Si, Thein T. Tun, and Mohan Rajesh Elara. "Modelling and Control of a Reconfigurable Robot for Achieving Reconfiguration and Locomotion with Different Shapes." Sensors 21, no. 16 (August 9, 2021): 5362. http://dx.doi.org/10.3390/s21165362.

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Area coverage is a crucial factor for a robot intended for applications such as floor cleaning, disinfection, and inspection. Robots with fixed shapes could not realize an adequate level of area coverage performance. Reconfigurable robots have been introduced to overcome the limitations of fixed-shape robots, such as accessing narrow spaces and cover obstacles. Although state-of-the-art reconfigurable robots used for coverage applications are capable of shape-changing for improving the area coverage, the reconfiguration is limited to a few predefined shapes. It has been proven that the ability of reconfiguration beyond a few shapes can significantly improve the area coverage performance of a reconfigurable robot. In this regard, this paper proposes a novel robot model and a low-level controller that can facilitate the reconfiguration beyond a small set of predefined shapes and locomotion per instructions while firmly maintaining the shape. A prototype of a robot that facilitates the aim mentioned above has been designed and developed. The proposed robot model and controller have been integrated into the prototype, and experiments have been conducted considering various reconfiguration and locomotion scenarios. Experimental results confirm the validity of the proposed model and controller during reconfiguration and locomotion of the robot. Moreover, the applicability of the proposed model and controller for achieving high-level autonomous capabilities has been proven.

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Naruse, Keitaro, and Tatsuya Sato. "Neighbor Topology for Dynamic Plane Coverage in Swarm Leading Control." International Journal of Artificial Life Research 3, no. 1 (January 2012): 59–75. http://dx.doi.org/10.4018/jalr.2012010106.

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The objective of this paper is to solve the dynamic plane coverage problem by the movement of multiple robots, for example, sprinkling water to a large field by several vehicles or aircrafts, in which all of the points in the field should be covered by the robots in an almost equal density. One of the ways to solve it is the swarm leading control method, in which one of the robots, called a target, moves along a path in the field, and all the other robots move around the target with a fixed distance. In the process, the topology of the robots affects to the efficiency of the dynamic plane coverage problem. If the topology is a tight one, the swarm can be stable but the coverage area can be limited in a small area. On the other hand, if it is a loose one, an opposite thing can be happened. In this paper, the relation between the topology and the efficiency is discussed numerically.

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Zheng, Yi, Baojun Lin, Rui Li, and Yutong Liu. "The Design and Maintenance of Low-Orbit Navigation Constellation for Traffic Control in a Smart City." Sensors 22, no. 23 (December 4, 2022): 9478. http://dx.doi.org/10.3390/s22239478.

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The traffic control issue in the smart city scenario gives rise to the higher requirements of Global Navigation Satellite System (GNSS) services, especially in terms of navigation accuracy, together with coverage continuity, and multiplicity. The dense urban environment leads to higher elevation angles for navigation in such areas, which requires a lower altitude of the constellation, as well as a larger number of satellites. In the existing literature, the design and maintenance of the Low Earth Orbit (LEO) navigation constellation that fulfills the requirements of the smart city are not provided. Hence, based on the requirements and constraints of the smart city scenario, this article studies the relation between orbital height, user elevation angle, and coverage. It designs the configuration of an LEO navigation constellation that not only achieves global sensing coverage, but also provides a continuous lane-level navigation service with multiple coverages for the key area. In addition, considering the atmospheric drag in low orbits and the constraint of satellite power and attitude control, a method is proposed by rotating solar panels to change the effective frontal area of the satellite to achieve relative configuration maintenance of the LEO constellation. The results show that the LEO navigation constellation has a 0 s revisit time in five chosen smart cities, and each city has more than four-times coverage every second; the Geographic Dilution of Precision (GDOP) values of five cities are smaller than 0.47. The average navigation accuracy of five cities is 2.01. With the conduction of the one-year station-keeping simulation, the phase deviation of two satellites is less than 0.6° and it gradually converges to 0.1°, where the semi-major axis deviation is less than 80 m. With our proposed method, the active station-keeping control is not needed in one year, and the fuel consumption can be reduced. Finally, the continuity of the navigation service can be assured.

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Gupta, Satyam, and Gunjan Kr. Gupta. "Energy and Coverage Area Test for Topology Control Algorithms of Wireless Sensor Networks." International Journal of Sensors Wireless Communications and Control 05, no. 999 (September 3, 2015): 1. http://dx.doi.org/10.2174/2210327905666150903215400.

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Din, Ahmad, Muhammed Yousoof Ismail, Babar Shah, Mohammad Babar, Farman Ali, and Siddique Ullah Baig. "A deep reinforcement learning-based multi-agent area coverage control for smart agriculture." Computers and Electrical Engineering 101 (July 2022): 108089. http://dx.doi.org/10.1016/j.compeleceng.2022.108089.

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Sun, Zeyu, Xiaofei Xing, Ben Yan, and Zhiguo Lv. "CMTN-SP: A Novel Coverage-Control Algorithm for Moving-Target Nodes Based on Sensing Probability Model in Sensor Networks." Sensors 19, no. 2 (January 10, 2019): 257. http://dx.doi.org/10.3390/s19020257.

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The non-consecutive coverage problem for the target nodes in Sensor Networks could lead to the coverage blind area and a large amount of redundant data, which causes the bottleneck phenomenon for the communication link. A novel Coverage Control Algorithm for Moving Target Nodes Based on Sensing Probability Model (CMTN-SP) is proposed in this work. Firstly, according to the probability theory, we derive the calculation method for the expectation of the coverage quality with multiple joint nodes, which aims to reduce the coverage blind area and improving network coverage rate. Secondly, we employ the dynamic transferring mechanism of the nodes to re-optimize the deployment of the nodes, which alleviates the rapid exhaustion of the proper network energy. Finally, it is verified via the results of the simulation that the network coverage quality could not only be improved by the proposed algorithm, but the proposed algorithm could also effectively curb the rapid exhaustion of the node energy.

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Sun, Qihai, Tianjun Liao, Zhi-Wei Liu, Ming Chi, and Dingxin He. "Fixed-Time Coverage Control of Mobile Robot Networks Considering the Time Cost Metric." Sensors 22, no. 22 (November 18, 2022): 8938. http://dx.doi.org/10.3390/s22228938.

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In this work, we studied the area coverage control problem (ACCP) based on the time cost metric of a robot network with an input disturbance in a dynamic environment, which was modeled by a time-varying risk density function. A coverage control method based on the time cost metric was proposed. The area coverage task that considers the time cost consists of two phases: the robot network is driven to cover the task area with a time-optimal effect in the first phase; the second phase is when the accident occurs and the robot is driven to the accident site at maximum speed. Considering that there were movable objects in the task area, a time-varying risk density function was used to describe the risk degree at different locations in the task area. In the presence of the input disturbance, a robust controller was designed to drive each robot, with different maximum control input values, to the position that locally minimized the time cost metric function in a fixed time, and the conditions for maximum control input were obtained. Finally, simulation results and comparison result are presented in this paper.

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NATES, S. V., M. FRIAS, S. BELFIORE, M. B. ISA, L. C. MARTINEZ, R. CHUIT, J. ARMONI, and C. LUXEMBURGER. "Effect on seroprevalence of anti-poliovirus antibodies and on vaccination coverage of the implementation of a DTwP-IPV-Hib vaccination programme in a South American city." Epidemiology and Infection 139, no. 6 (June 29, 2010): 826–35. http://dx.doi.org/10.1017/s0950268810001512.

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SUMMARYVaccination coverage and seroprevalence of poliovirus antibodies were assessed in Argentinean children (aged 8–12 and 19–21 months) living in Cordoba City pre-/post-implementation of a DTwP-IPV-Hib vaccination programme, and compared to those of controls from neighbouring populations receiving a full oral poliovirus vaccine schedule. Vaccination coverage was higher in control areas pre-intervention; this increased post-intervention in Cordoba (>90%) but not in control areas. Poliovirus types 1 and 2 seroprotection rates were >97% in all groups pre-/post-intervention. Type 3 seroprotection rates were generally lower, but increased post-intervention in Cordoba becoming significantly higher than control rates. Anti-type 1 and 3 antibody titres increased twofold and sevenfold, respectively, post-intervention, whereas anti-type 2 antibody titres decreased ~40% in the 8–12 months group. All titres increased in the 19–21 months post-intervention group. The introduction of a three-dose primary DTwP-IPV-Hib schedule maintained protection against poliovirus types 1 and 2, and increased protection against type 3, while vaccine coverage in the study area increased.

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Qian, Kai Guo, Li Mui, Tian Ma Zuo, and Zhi Qiang Xu. "A Survey on Coverage Control Technology in Wireless Sensor Network." Advanced Materials Research 774-776 (September 2013): 1556–59. http://dx.doi.org/10.4028/www.scientific.net/amr.774-776.1556.

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Deployment and coverage, studied how to effectively place and control of sensor nodes and to make WSN covered the monitoring area with the purpose of minimum the energy consumption and prolonging the network life cycle under the premise of guarantee the quality of service (QOS),are the primary problems for construction wireless sensor network. This paper analyzes important factors for resolve the coverage problem such as sensing models and deployment way, followed survey the state-of-the art coverage contro1 techniques and presents an overview and analysis of the solution proposed in recent research literature, Further research directions are pointed out in the end.

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Darabseh, Ala’, Evangelos Bitsikas, Brice Tedongmo, and Christina Pöpper. "On ADS-B Sensor Placement for Secure Wide-Area Multilateration." Proceedings 59, no. 1 (December 1, 2020): 3. http://dx.doi.org/10.3390/proceedings2020059003.

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As automatic dependent surveillance–broadcast (ADS-B) becomes more prevalent, the placement of on-ground sensors is vital for Air Traffic Control (ATC) to control the airspace. However, the current sensors are placed in an unstructured way that keeps some areas without coverage, and others are over-densified by sensors. Therefore, areas with coverage anomalies may cause issues that inhibit accurate ADS-B verifications as well as the availability of ADS-B altogether. In this paper, we tackle the ADS-B-specific optimal sensor placement (OSP) problem. Of importance are both the optimal coverage and the secure and accurate verification of received ADS-B messages. Specifically, we take into account the following objectives. First, we determine the minimum required number of sensors in order to cover a certain area like Europe. Second, we produce a better placement of the current sensors with respect to the security and accuracy of geometric dilution of precision (GDOP). Finally, we calculate how far the current sensor setup is from our derived optimal solution as well as the cost to reach the optimality. Our experiments show that the ideal fitness score for solving the OSP is below 0.1, meaning that the mean squared error (MSE) of the required and achieved GDOPs is significantly small, thus accomplishing a near-optimal setup.

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McPherson, R. M., D. J. Donahue, and S. L. Poe. "OVIPOSITION SITE SELECTION BY TETRANYCHUS URTICAE KOCH (ACARI: TETRANYCHIDAE) IN RESPONSE TO FENVALERATE AND PERMETHRIN RESIDUES ON SOYBEAN." Journal of Entomological Science 24, no. 1 (January 1, 1989): 26–33. http://dx.doi.org/10.18474/0749-8004-24.1.26.

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The oviposition site selection of Tetranychus urticae Koch in response to fenvalerate and permethrin residues on soybeans was examined in the laboratory. Five leaf treatment regimes were evaluated on potted soybeans (half-area vs. whole area and partial coverage vs. complete coverage) plus a distilled water control. Over 95% of the eggs were deposited on untreated halves of leaflets on which the other half was treated with either fenvalerate or permethin. Similar oviposition behavior was observed for both partial spray coverage, ca. 10% of the leaf area, or total coverage of the treated half leaflet. Over 95% of the eggs were observed on the leaf surface in the control, whereas, 40% and 30% of the eggs were suspended off the leaf surface that was totally covered with permethrin and fenvalerate, respectively. No differences were observed in the vertical distributions of eggs between control, and the permethrin and fenvalerate half-leaf treatments. More than 95% of the total eggs were observed on the leaf surface; however, few eggs were laid on the leaflet half containing the pyrethroid residue.

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Yakovlev, Sergiy, Oleksii Kartashov, and Alexander Mumrienko. "Формалізація та розв'язування задачі максимального покриття області з використанням бібліотеки Shapely для моніторингу територій." RADIOELECTRONIC AND COMPUTER SYSTEMS, no. 2 (May 18, 2022): 35–48. http://dx.doi.org/10.32620/reks.2022.2.03.

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To ensure the life of society, it becomes necessary to create systems for monitoring processes or objects using a network of sensors that can control part of the space (territory). Monitoring is understood as a systematic observation of the parameters of an object to obtain information on their compliance with the initial assumptions. Simultaneously, a physical model is constructed that links the characteristics of the object and information about the observation, which making it possible to identify the properties of the object. Such information is based on the processing of signals received using special control sensors. These signals are digitized to provide data on the coverage areas of the sensors. Thus, the physical model is associated with measuring the ability and quality of perception of control sensors, fixing the geometric relationship between them and points in space. The specified physical model corresponds to the geometric statement of the problem of covering the monitoring area with a set of geometric objects, the shape and size of which is determined by the coverage areas of the sensors. With a limited number of sensors, the problem arises of the maximum possible coverage of the area. In this article, we digress from the type of monitoring object and consider the geometric features of coverage problems that arise when designing systems for monitoring a space of various purposes. The current article presents constructive means of mathematical modeling for solving geometric problems of maximum coverage. To formalize the coverage conditions, the concept of constructing the configuration space of geometric objects and a special class of functions are used to establish the dependence of the measure (area, volume) of the coverage configuration on the placement parameters of the covering objects. Since it is extremely difficult to obtain an analytical form of these functions, an algorithmic approach to their calculation is proposed. The approach was implemented on the Pyton algorithm using the Shapely library. A computational experiment was planned and carried out to establish the dependence of the computation time on the number of geometric objects that make up the coverage configuration. To find the maximum coverage, the BFGS local optimization method of the Scipy.optimize package is used. Numerous examples of the implemenation of the proposed approach are given. Conclusions. The article substantiates the use of a software-algorithmic approach for formalization, calculation and optimization of maximum coverage configurations, which makes it possible to effectively solve complex problems of monitoring space and territories.

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Ramalingam, Balakrishnan, Prabakaran Veerajagadheswar, Muhammad Ilyas, Mohan Rajesh Elara, and Arunmozhi Manimuthu. "Vision-Based Dirt Detection and Adaptive Tiling Scheme for Selective Area Coverage." Journal of Sensors 2018 (December 30, 2018): 1–13. http://dx.doi.org/10.1155/2018/3035128.

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This paper proposes a visual dirt detection algorithm and a novel adaptive tiling-based selective dirt area coverage scheme for reconfigurable morphology robot. The visual dirt detection technique utilizes a three-layer filtering framework which includes a periodic pattern detection filter, edge detection, and noise filtering to effectively detect and segment out the dirt area from the complex floor backgrounds. Then adaptive tiling-based area coverage scheme has been employed to generate the tetromino morphology to cover the segmented dirt area. The proposed algorithms have been validated in Matlab environment with real captured dirt images and simulated tetrominoes tile set. Experimental results show that the proposed three-stage filtering significantly enhances the dirt detection ratio in the incoming images with complex floors with different backgrounds. Further, the selective dirt area coverage is performed by excluding the already cleaned area from the unclean area on the floor map by incorporating the tiling pattern generated by adaptive tetromino tiling algorithm.

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Dąbkowski, Mariusz, Paweł Skrzek, and Grzegorz Redlarski. "Behavior Based Complete Coverage Task of Unknown Area by an Autonomous Mobile Robot SCORPION with Static Obstacles in Environment." Solid State Phenomena 198 (March 2013): 73–78. http://dx.doi.org/10.4028/www.scientific.net/ssp.198.73.

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In the paper the behavior based control system of an autonomous mobile robot SCORPION is presented to execute the one of the most difficult navigation task, which is the complete coverage task of unknown area with static obstacles in the environment. The main principle assumed to design control system was that the robot should cover all area only once, if it possible, to optimize the length of path and energy consumption. All commercial robots like Roomba, Trilobite or IVO move using structured templates combined with random movement. Therefore the path of coverage is not optimal directions of movement are often chosen randomly, so robot covers the same area many times wasting time and energy. In paper the five main developed templates of movement were described to fulfill main task in ordered manner using primarily the way of the ox template of coverage [1, 2, 5, 1. The behavioral control system is implemented in a computer application written in Python [5]. In the paper the test methodology of the developed system on real mobile robot ERSP SCORPION equipped with IR sensors is presented. Graphical and quantitative results of tests of accomplishment of complete coverage task are given for 6 different configurations of obstacles in the robots environment. Conclusions are presented and discussed [5]. Ways to improve the quality indicators [1, of the task of complete coverage of a unknown area are also showed.

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Harter, Rachel, Katherine B. Morton, Ashley Amaya, and Derick Brown. "Estimating Net Coverage of Segments in ABS Frames." Field Methods 33, no. 1 (October 5, 2020): 68–84. http://dx.doi.org/10.1177/1525822x20960936.

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The literature has no standard method for estimating the coverage of area probability segments in address-based frames. Versatility is desirable for different study needs, but standardization improves comparability. Many segment estimates are simple ratios of counts of frame addresses to control totals, or net coverage ratios. Challenges to segment ratios include geocoding error, outdated control totals, errors in the address frame, and systematic exclusion of types of addresses. We tested various net coverage ratios on segments selected for the 2015 Residential Energy Consumption Survey, and we share our results and recommendations for using net coverage ratios for estimating coverage for segments.

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Wang, Hui, Youming Li, Tingcheng Chang, and Shengming Chang. "An Effective Scheduling Algorithm for Coverage Control in Underwater Acoustic Sensor Network." Sensors 18, no. 8 (August 1, 2018): 2512. http://dx.doi.org/10.3390/s18082512.

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Coverage maintenance is a bottleneck restricting the development of underwater acoustic sensor networks (UASNs). Since the energy of the nodes is limited, the coverage of UASNs may gradually decrease as the network operates. Thus, energy-saving coverage control is crucial for UASNs. To solve the above problems, this paper proposes a coverage-control strategy (referred to as ESACC) that establishes a sleep–wake scheduling mechanism based on the redundancy of deployment nodes. The strategy has two main parts: (1) Node sleep scheduling based on a memetic algorithm. To ensure network monitoring performance, only some nodes are scheduled to work, with redundant nodes in a low-power hibernation state, reducing energy consumption and prolonging the network lifetime. The goal of node scheduling is to find a minimum set of nodes that can cover the monitoring area, and a memetic algorithm can solve this problem. (2) Wake-up scheme. During network operation, sleeping nodes are woken to cover the dead nodes and maintain high coverage. This scheme not only reduces the network energy consumption but takes into account the monitoring coverage of the network. The experimental data show that ESACC performs better than current algorithms, and can improve the network life cycle while ensuring high coverage.

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Netto, Cesar de Cesar, Andrew Behrens, Matthieu Lalevee, Amanda Ehret, Nacime S. Mansur, Donald D. Anderson, John E. Femino, Francois Lintz, and Alessio Bernasconi. "Three-Dimensional Coverage Maps in the Assessment of Chopart Subluxation in Progressive Collapsing Foot Deformity." Foot & Ankle Orthopaedics 7, no. 1 (January 2022): 2473011421S0017. http://dx.doi.org/10.1177/2473011421s00176.

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Category: Basic Sciences/Biologics; Hindfoot; Midfoot/Forefoot Introduction/Purpose: Progressive collapsing foot deformity (PCFD), formerly termed Adult-Acquired Flatfoot Deformity (AAFD), is a complex 3D deformity characterized by peritalar subluxation (PTS) of the hindfoot through the triple joint complex. In this context, adjacent structures may adopt different positions and boney relations can change, producing areas increased contact or subluxation. The objective of this study was to use 3D distance maps (DMs) and coverage maps (CMs) from weightbearing CT (WBCT) images to assess subluxation across the Chopart joint in PCFD patients. We hypothesized that CMs would show decreased coverage indicative of subluxation through certain regions of the Chopart joint in PCFD patients when compared to the controls. Methods: In this IRB-approved, retrospective case-control study, we analyzed WBCT data of 18 consecutive patients with flexible PCFD and 10 controls. Using principle component analysis, candidate coverage area was divided into nine regions on the talar head and 4 regions on the calcaneal-cuboid (CC) articular surface. Novel 3D distance mapping (DM) technique was used to objectively characterize joint coverage across the entire Chopart joint surface on both the talus and calcaneus. Distance maps were measured in millimeters and colored to highlight covered areas. Areas with distances less than 4mm were defined to be covered, while areas with distances greater than 4mm were considered to be uncovered. Joint coverage was defined as percentage of articular area with DMs lower than 4 mm. Coverage Maps (CM) were created to highlight areas of coverage (teal) versus non- coverage (pink). Comparisons were performed with independent t-tests, assuming unequal variances. P values <.05 were considered significant. Results: Changes in coverage percentages of PCFD cases relative to controls are indicated in attached figure 1 . The middle lateral region of the talar head was found to have a 9% increase in coverage in PCFD cases relative to the controls (p = 0.011). The plantar region of the calcaneal-cuboid joint was found to have a 18% decrease in coverage compared to the controls. Except for the dorsal medial regions, the medial side of the talar head saw overall decreases in coverage. However, these values were not statistically significant. On the calcaneus, the plantar region of the calcaneal-cuboid joint was found to have a significant coverage decrease of 18% relative to the controls (p = 0.017). There was also a decrease in coverage observed in the medial region of the calcaneal-cuboid joint and an increase in the dorsal and lateral areas. Conclusion: Our results support the occurrence of significant Chopart joint changes in early flexible PCFD. Increased lateral and decreased medial/plantar talar head coverage point to internal rotation and plantarflexion of the talus. Associated dorsal migration of the cuboid where plantar and medial areas have decreased coverage indicate subluxation through the entirety of the Chopart joint. Novel 3D coverage mapping enabled objective quantification of subluxation though the Chopart joint in early stage PCFD. These findings may assist clinical decision making regarding the restoration of normal joint alignment during PCFD corrections. Further studies are needed to establish thresholds of change associated with degeneration.

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Salman, Hadi, Elif Ayvali, and Howie Choset. "Multi-Agent Ergodic Coverage with Obstacle Avoidance." Proceedings of the International Conference on Automated Planning and Scheduling 27 (June 5, 2017): 242–49. http://dx.doi.org/10.1609/icaps.v27i1.13816.

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Autonomous exploration and search have important applications in robotics. One interesting application is cooperative control of mobile robotic/sensor networks to achieve uniform coverage of a domain. Ergodic coverage is one solution for this problem in which control laws for the agents are derived so that the agents uniformly cover a target area while maintaining coordination with each other. Prior approaches have assumed the target regions contain no obstacles. In this work, we tackle the problem of static and dynamic obstacle avoidance while maintaining an ergodic coverage goal. We pursue a vector-field-based obstacle avoidance approach and define control laws for idealized kinematic and dynamic systems that avoid static and dynamic obstacles while maintaining ergodicity. We demonstrate this obstacle avoidance methodology via numerical simulation and show how ergodicity is maintained.

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Gadiraju, Venkata, Hsiao-Chun Wu, Costas Busch, Prasanga Neupane, Shih Yu Chang, and Scott C. H. Huang. "Novel Sensor/Access-Point Coverage-Area Maximization for Arbitrary Indoor Polygonal Geometries." IEEE Wireless Communications Letters 10, no. 12 (December 2021): 2767–71. http://dx.doi.org/10.1109/lwc.2021.3116561.

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Chen, Yongbo, Shoudong Huang, and Robert Fitch. "Active SLAM for Mobile Robots With Area Coverage and Obstacle Avoidance." IEEE/ASME Transactions on Mechatronics 25, no. 3 (June 2020): 1182–92. http://dx.doi.org/10.1109/tmech.2019.2963439.

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Allen, Alan A., and Dean H. Dale. "OIL SLICK CLASSIFICATION: A SYSTEM FOR THE CHARACTERIZATION AND DOCUMENTATION OF OIL SLICKS." International Oil Spill Conference Proceedings 1997, no. 1 (April 1, 1997): 315–22. http://dx.doi.org/10.7901/2169-3358-1997-1-315.

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ABSTRACT This paper provides a classification system for describing and quantifying floating oil slicks. Simple, easy-to-remember descriptors and numerical values are used to establish standard terminology for the physical properties of an oil slick. Such terms and their numerical correlations are used to establish “codes” by which important descriptive parameters can be abbreviated. Such codes include oil type (i.e., groups I-V), oil geometry (i.e., area and shape), and oil condition (i.e., percent coverage, average thickness, nature of coverage, and percent emulsification). A brief sequence of such codes can provide a standardized “characterization” of an entire oil slick and any internal areas of significant difference. A unique surface distribution factor (SDF) is also provided for a broad range of possible volume/area relationships. Characterized by commonly observed slick geometry and condition factors, each surface distribution factor corresponds to an estimated “volume-per-unit-area” value. Combined with areal coverage rates (i.e., “area-per-unit-time” values) for various dynamic response systems, the SDF provides a rapid estimate of potential volume control rates for specific systems on a given slick. The classification scheme could simplify and standardize procedures used by observers during surface and aerial reconnaissance efforts; it could reduce the time and space needed to document such observations; and it could simplify verbal communications between spotter aircraft and vessels, between vessels, and between field operations and onshore/command groups.

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Lin, Jeng-Liang, Heping Zhu, and Peter Ling. "Amendment of Herbicide Spray Solutions with Adjuvants to Modify Droplet Spreading and Fading Characteristics on Weeds." Applied Engineering in Agriculture 35, no. 5 (2019): 713–21. http://dx.doi.org/10.13031/aea.13339.

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Abstract.Improving the coverage area and fading time of herbicidal droplets on weeds has the potential to enhance the biological control effectiveness. Droplet spreading and fading behaviors on five different weeds were characterized for spray solutions containing a 1.25% glyphosphate Rodeo herbicide amended with each of three different adjuvants (nonionic surfactant Kinetic, nonionic organosilicone surfactant DyneAmic, and nonionic surfactant and antifoaming agent Preference). The five weeds were ragweed, crabgrass, yellow nutsedge, common purslane, and spurge. Tests were conducted by depositing single 300 and 600 µm herbicidal droplets with different adjuvant concentrations on weed leaves inside an environment control chamber. A droplet at a higher adjuvant concentration had greater coverage area on weed surfaces. Preference-amended herbicidal droplets had the largest coverage area increase for all five weeds, and generally followed by droplets with Kinetic and DyneAmic except for 300 µm droplet on purslane and 600 µm droplet on spurge. In comparison with the herbicidal solution containing Rodeo and water only, with addition of adjuvants the 600 µm droplets increased the coverage area by 2.13 to 5.47, 1.76 to 2.56, 1.84 to 2.07, and 2.40 to 4.49-fold on crabgrass, yellow nutsedge, common purslane, and spurge, respectively, while the 300 µm droplets increased the coverage area on ragweed by 3.88 to 5.86-fold. In contrast, fading times of all 300 µm droplets decreased with the adjuvant addition except for DyneAmic applied on purslane. However, fading times of 600 µm droplets did not have increase or decrease trends with adjuvants, which depended on types of the adjuvant and weed. The overall comparison by integrated index (coverage area × fading time) indicated that a spray droplet at higher adjuvant concentration was likely to have a higher integrated index. In addition, Preference amended droplets had significantly more integrated index increase for crabgrass and nutsedge, while DyneAmic had more increase for purslane. Therefore, appropriate selections of spray adjuvants during herbicide applications could significantly increase droplet deposition effectiveness for controlling specific weeds. Keywords: Spray droplet, Spray additive, Herbicide application, Surfactant, Weed control.

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Ramsey, Shirley. "Science and technology: when do they become front page news?" Public Understanding of Science 3, no. 1 (January 1994): 71–82. http://dx.doi.org/10.1088/0963-6625/3/1/005.

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This study suggests that press reports of science and technology increase in complexity, in depth and breadth of coverage, and in prominent placement in the news hole in relation to increased diversity or pluralism of supporting environments. It also suggests that system changes that produce interest and expanded knowledge of science provide opportunities for clashes of interests resulting in localized conflict and thus increased news coverage. `Change' in an innovative area appears to link up conceptually in copy with theory, action descriptions, and visualization through metaphor. The study used content analysis to compare a more innovative, economically progressive `research' area in the United States with an economically flat `control' area; these areas were selected using National Bureau of the Census and local economic development office statistics.

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Rizvi, Sajjad, Hassaan Khaliq Qureshi, Syed Ali Khayam, Veselin Rakocevic, and Muttukrishnan Rajarajan. "A1: An energy efficient topology control algorithm for connected area coverage in wireless sensor networks." Journal of Network and Computer Applications 35, no. 2 (March 2012): 597–605. http://dx.doi.org/10.1016/j.jnca.2011.11.003.

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Ramarakula, Madhu. "An Efficient Uplink Power Control Algorithm for LTE-Advanced Relay Networks to Improve Coverage Area." Wireless Personal Communications 110, no. 3 (September 14, 2019): 1075–87. http://dx.doi.org/10.1007/s11277-019-06774-4.

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Aftab, Farooq. "Coverage Area Control Approach using Dimming Factor of LED Transmitter in Light Fidelity (Li-Fi)." International Journal of Advanced Science and Technology 95 (October 31, 2016): 23–36. http://dx.doi.org/10.14257/ijast.2016.95.03.

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Tang, Liang, Mingzhu He, and Xinrong Li. "Verification of Fractional Vegetation Coverage and NDVI of Desert Vegetation via UAVRS Technology." Remote Sensing 12, no. 11 (May 28, 2020): 1742. http://dx.doi.org/10.3390/rs12111742.

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Desertification control and scientific evaluation of desert ecosystem sustainability are important issues for countries along the Silk Road Economic Belt. Fractional vegetation coverage (FVC) is used as a quantitative indicator to describe the vegetation coverage of desert ecosystems. Although satellite remote sensing technology has been widely used to retrieve FVC at the regional and global scale, the authenticity evaluation of the inversion results has been flawed. To gain insight into the composition, structure and changes of desert vegetation, it is important to assess the accuracy of FVC and explore the relationship between FVC and meteorological factors. Therefore, we adopted unmanned aerial vehicle remote sensing (UAVRS) technology to verify the inversion results and analyse the practicability of MODIS-NDVI (where NDVI = normalized difference vegetation index) products in desert areas. To provide a new method for the estimation of vegetation coverage in the natural state, the relationships between vegetation coverage and four meteorological factors, namely, land surface temperature, temperature, precipitation and evaporation were analysed. The results showed that using the original MODIS-NDVI data product with a spatial resolution of 250 m to invert vegetation coverage is practical in desert areas (coefficient of determination (R2) = 0.83, root mean square error (RMSE) = 0.052, normalized root mean square error (NRMSE) = 42.94%, mean absolute error (MAE) = 0.007) but underestimates vegetation coverage in the study area. MODIS-NDVI data products are different from the real NDVI in the study area. Correcting MODIS-NDVI data products can effectively improve the accuracy of the inversion. When extracting vegetation coverage in this area, the scale has little effect on the results. There is a significant correlation between precipitation, evaporation and FVC in the area, but the interaction of temperature and land surface temperature with precipitation and evaporation also has a considerable impact on FVC, and evaporation has a substantial impact on FVC values inverted from MODIS-NDVI data (FVCM), When exploring the relationship between vegetation coverage and meteorological elements, if vegetation coverage is retrieved from MODIS-NDVI data products or MODIS-NDVI data, when considering temperature and precipitation, the effect of evaporation should also be considered. In addition, meteorological factors can be used to predict FVC (R2 = 0.7364, RMSE = 0.0623), which provides a new method for estimating FVC in areas with less manual intervention.

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Chen, Li Jun. "An Improved Clustering Algorithm Based on Coverage Area for Wireless Sensor Networks." Advanced Materials Research 542-543 (June 2012): 643–46. http://dx.doi.org/10.4028/www.scientific.net/amr.542-543.643.

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Clustering is an effective topology control approach in wireless sensor networks, which can increase network scalability and lifetime. A clustering algorithm based on the total number of neighbor nodes is proposed to maximize the lifetime of the network. The larger amount of neighbor nodes, the more chance a node has to be selected as a cluster head. Therefore, it can ensure the minimum cluster heads in the whole network. By closing the communication parts of cluster head to avoid selecting as cluster head in next epoch, the energy of the whole system is consumed symmetrically. The simulations demonstrate the effectiveness of the algorithm.

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Lin, Jeng-Liang, and Heping Zhu. "Fading Activities of Herbicidal Droplets Amended with Emulsifiable Spray Adjuvants on Cucurbitaceous Leaves." Transactions of the ASABE 61, no. 6 (2018): 1881–88. http://dx.doi.org/10.13031/trans.13061.

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Abstract. Understanding reactions of surfactant-amended droplets on difficult-to-wet weed surfaces could help develop application strategies to increase herbicide efficacy. Behaviors of herbicidal droplets containing different emulsifiable anti-evaporation spray adjuvants were investigated by characterizing 250 and 450 µm herbicidal droplet dispersion and fading time on cucurbitaceous leaves placed inside a 20°C chamber at 30% and 60% relative humidity (RH). Droplet maximum coverage area increased with droplet size but not with RH, while droplet fading time increased with both droplet size and RH. Despite 450 µm droplets having greater maximum coverage area than 250 µm droplets, the larger droplets had higher fading rates and lower ratios of maximum coverage area to droplet volume. Droplet maximum coverage area and fading time on leaves were affected by adding spray adjuvants to the herbicide-only solution. The Uptake surfactant was more effective than the other two surfactants (AntiEvap+BS1000 and Enhance) in increasing droplet maximum coverage area and fading time. Compared to the herbicide-only solution, addition of Uptake surfactant to the herbicide solution could increase maximum coverage area by 68% and 52% for 250 and 450 µm droplets, respectively, but addition of AntiEvap+BS1000 or Enhance surfactants did not show significant increase. Similarly, addition of Uptake surfactant to the herbicide-only solution increased droplet fading times by 11.1% and 13.2% at 30% and 60% RH, respectively, for 250 µm droplets and by 34.7% and 2.8% at 30% and 60% RH, respectively, for 450 µm droplets. In contrast, addition of AntiEvap+BS1000 surfactant reduced fading time, and addition of Enhance surfactant did not significantly affect fading time. Therefore, appropriate selection of spray adjuvants for herbicide applications could significantly influence droplet deposit behaviors on cucurbitaceous leaves, leading to improved effectiveness of weed control. Keywords: Herbicide application, Spray deposition, Spray droplet, Surfactant, Weed control.

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Journal articles on the topic 'Area Coverage Control'

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