scholarly journals Throughput Maximization for UAV-Enabled Relaying in Wireless Powered Communication Networks

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 2989 ◽  
Author(s):  
Yinfeng Li ◽  
Dingcheng Yang ◽  
Yu Xu ◽  
Lin Xiao ◽  
Haole Chen
Keyword(s):  
Communication Networks ◽  
Optimal Solution ◽  
Access Point ◽  
Throughput Maximization ◽  
System Throughput ◽  
Multiple Sources ◽  
Information Causality ◽  
Suboptimal Solution ◽  
The One ◽  
Dependent Processes

This paper investigates mobile relaying in wireless powered communication networks (WPCN), where an unmanned aerial vehicle (UAV) is employed to help information delivery from multiple sources to destination with communication channels severely blocked. The sources are low-power without energy supply. To support information transmission, the UAV acts as a hybrid access point (AP) to provide wireless power transfer (WPT) and information reception for sources. We set the issue of system throughput maximization as the optimization problem. On the one hand, the system is subject to the information causality constraint due to the dependent processes of information reception and transmission for the UAV. On the other hand, the sources are constrained by a so-called neutrality constraints due to the dependent processes of energy harvesting and energy consumption. In addition, we take account of the access delay issue of all ground nodes. Specifically, two paradigms of delay-tolerant case and delay-sensitive case are presented. However, the formulated problem including optimizations for time slot scheduling, power allocation and UAV trajectory is non-convex and thus is difficult to obtain its optimal solution. To tackle this problem, we apply the successive convex approximation (SCA) technique and propose an iterative algorithm by which a suboptimal solution can be achieved. Simulation results validate our proposed design, and show that the obtained suboptimal solution is high-quality, as compared to benchmark scheme.

scholarly journals Deep learning-based optimal placement of a mobile HAP for common throughput maximization in wireless powered communication networks

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Hong-Sik Kim ◽  
Inwhee Joe
Keyword(s):  
Deep Learning ◽  
Convex Function ◽  
Communication Networks ◽  
Complex Function ◽  
Access Point ◽  
Throughput Maximization ◽  
Optimal Placement ◽  
Mathematical Methods ◽  
Hybrid Access ◽  
Wireless Device

AbstractHybrid access point (HAP) is a node in wireless powered communication networks (WPCN) that can distribute energy to each wireless device and also can receive information from these devices. Recently, mobile HAPs have emerged for efficient network use, and the throughput of the network depends on their location. There are two kinds of metrics for throughput, that is, sum throughput and common throughput; each is the sum and minimum value of throughput between a HAP and each wireless device, respectively. Likewise, two types of throughput maximization problems can be considered, sum throughput maximization and common throughput maximization. In this paper, we focus on the latter to propose a deep learning-based methodology for common throughput maximization by optimally placing a mobile HAP for WPCN. Our study implies that deep learning can be applied to optimize a complex function of common throughput maximization, which is a convex function or a combination of a few convex functions. The experimental results show that our approach provides better performance than mathematical methods for smaller maps.

scholarly journals Age-Aware Utility Maximization in Relay-Assisted Wireless Powered Communication Networks

Entropy ◽  
2021 ◽  
Vol 23 (9) ◽  
pp. 1177
Author(s):  
Ning Luan ◽  
Ke Xiong ◽  
Zhifei Zhang ◽  
Haina Zheng ◽  
Yu Zhang ◽  
...  
Keyword(s):  
Communication Networks ◽  
System Performance ◽  
Numerical Experiments ◽  
Utility Maximization ◽  
Stackelberg Game ◽  
Optimal Solution ◽  
Access Point ◽  
Convex Problem ◽  
Slack Variable ◽  
Relaying Systems

This article investigates a relay-assisted wireless powered communication network (WPCN), where the access point (AP) inspires the auxiliary nodes to participate together in charging the sensor, and then the sensor uses its harvested energy to send status update packets to the AP. An incentive mechanism is designed to overcome the selfishness of the auxiliary node. In order to further improve the system performance, we establish a Stackelberg game to model the efficient cooperation between the AP–sensor pair and auxiliary node. Specifically, we formulate two utility functions for the AP–sensor pair and the auxiliary node, and then formulate two maximization problems respectively. As the former problem is non-convex, we transform it into a convex problem by introducing an extra slack variable, and then by using the Lagrangian method, we obtain the optimal solution with closed-form expressions. Numerical experiments show that the larger the transmit power of the AP, the smaller the age of information (AoI) of the AP–sensor pair and the less the influence of the location of the auxiliary node on AoI. In addition, when the distance between the AP and the sensor node exceeds a certain threshold, employing the relay can achieve better AoI performance than non-relaying systems.

scholarly journals A NOMA-Combined Hybrid Approach for SDMA Improvement in Wireless Powered Communication Networks

2021 ◽  
Author(s):  
Juhyun Maeng ◽  
Mwamba Kasongo Dahouda ◽  
Inwhee Joe
Keyword(s):  
Communication Networks ◽  
Mobile Communications ◽  
Power Transmission ◽  
Transmission Rate ◽  
Hybrid Approach ◽  
Access Point ◽  
A Cell ◽  
Distance Difference ◽  
The One ◽  
To Receive

AbstractWireless Powered Communication Network (WPCN) consists of Hybrid Access Point (HAP) that performs power transmission and data collection at the same time, and multiple nodes that can transmit data. In WPCN, depending on the wireless communication environment, the nodes cannot be able to transmit data because they can fail to receive power. Hence, increasing the transmission rate under a given resource is one of the very important issues. In ordinary mobile communications, a cell is divided into several sectors and the data is collected through multiple antennas to increase the transmission rate using SDMA. As a result, if the number of nodes in the one sector increases, the interference between nodes increases, and the transmission rate may decrease. Accordingly, in order to maximize performance, the number of nodes that can exist in a sector must be limited. The transmission rate between nodes according to the distance difference may not be fair because the nodes far from the HAP charge a small amount of power by attenuation of the signal, and the nodes close to the HAP charge a relatively large amount of power. Therefore, we propose Hybrid SDMA and Non-Orthogonal Multiple Access (NOMA) as a way to maximize the performance in term of both Sum-Throughput and Fairness. Also, we prove that there is a tradeoff between Sum-Throughput and Fairness according to the number of sectors. The simulation results show that the Hybrid SDMA and NOMA improves the performance substantially compared to the conventional SDMA.

Throughput Maximization of Wireless-Powered Communication Networks: An Energy Threshold Approach

2021 ◽  
pp. 1-1
Author(s):  
Kechen Zheng ◽  
Xiaoying Liu ◽  
Biao Wang ◽  
Haifeng Zheng ◽  
Kaikai Chi ◽  
...  
Keyword(s):  
Communication Networks ◽  
Energy Threshold ◽  
Throughput Maximization ◽  
Threshold Approach

scholarly journals Challenges for a QCD axion at the 10 MeV scale

2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Jia Liu ◽  
Navin McGinnis ◽  
Carlos E. M. Wagner ◽  
Xiao-Ping Wang
Keyword(s):  
Higgs Boson ◽  
Standard Model ◽  
Structure Constant ◽  
Fine Structure Constant ◽  
Multiple Sources ◽  
Standard Model Extension ◽  
Mixing Angles ◽  
Quark Masses ◽  
Model Extension ◽  
The One

Abstract We report on an interesting realization of the QCD axion, with mass in the range $$ \mathcal{O} $$ O (10) MeV. It has previously been shown that although this scenario is stringently constrained from multiple sources, the model remains viable for a range of parameters that leads to an explanation of the Atomki experiment anomaly. In this article we study in more detail the additional constraints proceeding from recent low energy experiments and study the compatibility of the allowed parameter space with the one leading to consistency of the most recent measurements of the electron anomalous magnetic moment and the fine structure constant. We further provide an ultraviolet completion of this axion variant and show the conditions under which it may lead to the observed quark masses and CKM mixing angles, and remain consistent with experimental constraints on the extended scalar sector appearing in this Standard Model extension. In particular, the decay of the Standard Model-like Higgs boson into two light axions may be relevant and leads to a novel Higgs boson signature that may be searched for at the LHC in the near future.

scholarly journals Automation of the one-storey underground parking space organization

2021 ◽  
Vol 284 ◽  
pp. 06012
Author(s):  
Natalia Knyazeva ◽  
Anastasia Kolosova
Keyword(s):  
Evolutionary Algorithms ◽  
Urban Area ◽  
Optimal Solution ◽  
Parking Space ◽  
Space Planning ◽  
Parking Lots ◽  
Legal Documents ◽  
Space Organization ◽  
Big Cities ◽  
The One

With the growing car population in big cities, the problem of its keeping in conditions of a compact urban area has happened. The organisation of parking space in a different way has resolved this issue. Underground parking was in demand in many countries even in the XX century. By the way, they are becoming more and more popular now. The design of car parking is based on legal documents, which regulate the size of car parking seats and the width of the passage inside the garage. It is expedient to use evolutionary algorithms as one of the tools of algorithmic modelling for automation of design the car parking lots and for identifying the most effective and profitable way of the car parking space planning. So, the process of looking for the most optimal solution in underground car parking designing.

scholarly journals RF Energy Harvesting with Multiple Sources in Wireless Mesh Network

2018 ◽  
Vol 10 (2) ◽  
pp. 606 ◽  
Author(s):  
K.N Puniran ◽  
Ahmad Robiah ◽  
Rudzidatul Akmam Dziyauddin
Keyword(s):  
Energy Harvesting ◽  
Base Station ◽  
Mesh Network ◽  
System Throughput ◽  
Power Splitting ◽  
Multiple Sources ◽  
Wireless Mesh ◽  
Optimal Value ◽  
Rf Energy ◽  
Single Relay

Energy harvesting (EH) module for wireless sensor network has become a promising feature to prolong the conventional battery inside the devices. This emerging technology is gaining interest from sensor manufacturers as well as academicians across the globe. The concept of employing EH module must be cost effective and practical. In such, the use of EH module type besides RF is more realistic due to the size of the scavenger module, the availability of the resources and conversion efficiency. Most of the oil and gas plants have some drawbacks in scavenging RF from surrounding (i.e. router, Wi-Fi, base station, cell phone) due to its placement in remote area and thus limited energy sources could be a threat in this application. Multiple sources, including co-channel interference (CCI) in any constraint nodes is a feasible way of scavenging several wastes from ambient RF energy via wireless mesh topology. In this paper, a 3-node decode-and-forward (DF) model is proposed where the relay node is subject to an energy constraint. Multiple primary sources and CCI are added in the system model known as Multiple-Source and Single-Relay (MSSR). A mathematical model is derived in Time Switching Relaying (TSR) and Power Splitting Relaying (PSR) schemes to obtain an average system throughput at a destination. Numerical simulation with respect to the average throughput and EH ratio was performed and compared with the Single-Source and Single-Relay (SSSR) and ideal receiver. By applying multiple sources and CCI as an energy enhancement at the constraint node, the optimal value of EH ratio for TSR can be reduced significantly by 10% as compared to the ideal receiver whereas the optimal value of EH ratio for PSR is outweigh TSR in terms of overall system throughput.

Overview Statement on Medical Records

PEDIATRICS ◽  
1975 ◽  
Vol 56 (2) ◽  
pp. 329-329 ◽  
Author(s):  
Hugh C. Thompson ◽  
Stanton J. Barron ◽  
John P. Connelly ◽  
Andrew Margileth ◽  
Richard Olmsted ◽  
...  
Keyword(s):  
Medical Record ◽  
Medical Records ◽  
Medical Information ◽  
Third Party ◽  
Specific Information ◽  
Multiple Sources ◽  
Chart Audit ◽  
Working Together ◽  
The One ◽  
The Individual

Historically, medical records have been maintamed by individual physicians to record specific information concerning patients. This information was often understandable only to the writer. The data were of outstanding events. This was thought to be sufficient documentation for patient care. Records are now read by others than the individual physicians. Groups of physicians working together often share the same patients and their records. Patients may have multiple sources of care. Our population has become more mobile which makes it necessary to transfer vast amounts of medical information. The medical record many times is the one instrument which gives a complete and continuous documentation of the patient's medical history. Third-party payers are requesting access to medical records to document services provided. Chart audit is being tested as a mechanism for evaluating physician performance. Records must reflect what the physician does in order to be useful in such an appraisal. Much clinical research on the delivery of health care depends on accurately kept records which are easily interpreted. A chart is also a legal document for the protection of the physician as well as the patient. Thus, records will be used in other than traditional ways. Proper confidentiality must be maintained when such uses are necessary. Physicians generally agree as to the essential content of a medical record. However, there is little unanimity as to the structure of the chart. No one system of keeping records is now appropriate for all situations. The maintenance of adequate charts requires additional cost in both time and money.

Sign in / Sign up

Export Citation Format

Share Document