Energy Efficient Relay Assisted Wireless Multicast System

2013 ◽  
Vol 441 ◽  
pp. 941-946
Author(s):  
Ting Song Jiang ◽  
Xi Luan ◽  
Xiao Yan Xu ◽  
Jian Jun Wu

In this paper, the optimization based on energy efficiency in a relay assisted wireless multicast system, where a single source communicates with multiple destinations with the help of an amplify-and-forward relay, is proposed. We assume that the source cannot reach the destinations directly, and thus the relay forwards the signal in two hops. Under the performance objective of maximizing the number of bits that the source sends to all destinations per Joule of the total energy spent, we formulate the optimization problem based on high SNR approximation, and prove that the problem can be extended to a standard Geometric Programming (GP) problem, which is a well-studied class of nonlinear and nonconvex optimization and has regular solutions. Finally, we provide a set of numerical results to illustrate energy efficiency corresponding to different channel conditions.

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yilong Gu ◽  
Yangchao Huang ◽  
Hang Hu ◽  
Weiting Gao ◽  
Yu Pan

With the consolidation of the Internet of Things (IoT), the unmanned aerial vehicle- (UAV-) based IoT has attracted much attention in recent years. In the IoT, cognitive UAV can not only overcome the problem of spectrum scarcity but also improve the communication quality of the edge nodes. However, due to the generation of massive and redundant IoT data, it is difficult to realize the mutual understanding between UAV and ground nodes. At the same time, the performance of the UAV is severely limited by its battery capacity. In order to form an autonomous and energy-efficient IoT system, we investigate semantically driven cognitive UAV networks to maximize the energy efficiency (EE). The semantic device model for cognitive UAV-assisted IoT communication is constructed. And the sensing time, the flight speed of UAV, and the coverage range of UAV communication are jointly optimized to maximize the EE. Then, an efficient alternative algorithm is proposed to solve the optimization problem. Finally, we provide computer simulations to validate the proposed algorithm. The performance of the joint optimization scheme based on the proposed algorithm is compared to some benchmark schemes. And the simulation results show that the proposed scheme can obtain the optimal system parameters and can significantly improve the EE.


2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Haibin Niu ◽  
Xinyu Zhao ◽  
Liming Hou ◽  
Dongjun Ma

Using unmanned aerial vehicles (UAVs) in emergency communications is a promising technology because of their flexible deployment, low cost, and high mobility. However, due to the limited energy of the onboard battery, the service duration of the UAV is greatly limited. In this paper, we study an emerging energy-efficient UAV emergency network, where a UAV works as an aerial base station to serve a group of users with different statistical quality-of-service (QoS) constraints in the downlink. In particular, the energy efficiency of the UAV is defined as the sum effective capacity of the downlink users divided by the energy consumption of the UAV, which includes the energy consumed by communication and the energy consumed by hovering. Then, we formulate an optimization problem to maximize the energy efficiency of the UAV by jointly optimizing the UAV’s altitude, downlink transmit power, and bandwidth allocation while meeting a statistical delay QoS requirement for each user. The formulated optimization problem is a nonlinear nonconvex optimization problem of fractional programming, which is difficult to solve. In order to deal with the nonconvex optimization problem, the following two steps are used. First, we transform the fractional objective function into a tractable subtractive function. Second, we decompose the original optimization problem into three subproblems, and then, we propose an efficient iterative algorithm to obtain the energy efficiency maximization value by using the Dinkelbach method, the block coordinate descent, and the successive convex optimization technique. Extensive simulation results show that our proposed algorithm has significant energy savings compared with a benchmark scheme.


Author(s):  
Gennadii Kaniuk ◽  
◽  
Andrii Mezeria ◽  
Victoria Kniazeva ◽  
Tetiana Fursova ◽  
...  

This work is devoted to intensification of the power efficiency of computerized systems of con-trol by the pumping units group of oil pumping stations of the main lines. The criterion of the energy efficiency is a minimum total energy loss. The goal set can be reached by the develop-ment of algorithms of the energy efficient control. The most important scientific result based on the identification of the mathematical models of the objects controlled is the efficient algorithm for controlling the group of oil pumping units. It allows determining in real time the operation modes of separate pumping units, upon which the total energy losses will be minimal. The sig-nificance of the results obtained consists in the energy losses decrease across the main oil pipe-line during the combined control by the pumping units groups. Their practical significance con-sists in decreasing the cost of oil transportation at the expense of decreasing the energy con-sumed by the pumping units. The main stages of plotting the modes maps were presented of the efficient operation of the pumping units based on the definition of the necessary rotation fre-quencies and positions of the regulating valves. Experimentally was performed the analysis of the operation modes of the pumping unit using different methods for productivity regulation, and their comparative energy efficiency was shown. The experimental data extrapolation was carried out, and, on its basis, the possible economic effect was determined brought by the use of the energy-conserving systems of the controlling the group of pumping systems.


2012 ◽  
Vol 13 (2) ◽  
pp. 36-50
Author(s):  
Muhammad Riaz Akbar ◽  
Neil Hewitt ◽  
George Heaney ◽  
Lay-Cheng Lim ◽  
Syeda Shabnum Najaf

Pakistan is currently facing acute energy shortages. The local energy production is inadequate to meet domestic needs and support economic growth which has decelerated the pace of economic development and industrialisation of the country. The residential sector consumes a significant chunk of the total energy resource available in the country. In this context there is a need to look for avenues where energy savings can be realised. The concept of energy efficient homes and sustainable dwellings is at the centre of energy saving debate but is still in its early stages of development in Pakistan. The main instruments to realise energy savings in any energy management regime stem from legal and regulatory frameworks, institutional and individual delivery capacity and enforcement mechanisms employed by the concerned authorities. This study looks into these regimes at national, regional and local levels and analyses their adequacy as to the objectives of their development and institution. The paper starts by detailing the prevailing situation with respect to (total) energy consumption and energy efficient living in Pakistan in the first part. Next, it analyses energy efficiency provisions for residential sector within the current legal and regulatory frameworks and identifies the challenges to such developments. The research method involves content analysis of policy, legal and regulatory provisions in Pakistan and institutional response through a dichotomous awareness survey about the existence and use of Building Energy Code of Pakistan, which is complementary to the main methodology. The research finds that there is need to adopt a holistic approach to improve the prevailing legal and regulatory regimes, which are weak and poorly defined. The capacity, enforcement mechanisms and environmental performance of these regimes are also important issues. The outcomes of this study are recommendations for the necessary policy responses to better enable Energy Efficient Homes in Pakistan. Key Words: Efficiency, Passive, Design, Legal and Regulatory, Capacity


2018 ◽  
pp. 113-119
Author(s):  
Gennady Ya. Vagin ◽  
Eugene B. Solntsev ◽  
Oleg Yu. Malafeev

The article analyses critera applying to the choice of energy efficient high quality light sources and luminaires, which are used in Russian domestic and international practice. It is found that national standards GOST P 54993–2012 and GOST P 54992– 2012 contain outdated criteria for determining indices and classes of energy efficiency of light sources and luminaires. They are taken from the 1998 EU Directive #98/11/EU “Electric lamps”, in which LED light sources and discharge lamps of high intensity were not included. A new Regulation of the European Union #874/2012/EU on energy labelling of electric lamps and luminaires, in which these light sources are taken into consideration, contains a new technique of determining classes of energy efficiency and new, higher classes are added. The article has carried out a comparison of calculations of the energy efficiency classes in accordance with GOST P 54993 and with Regulation #874/2012/EU, and it is found out that a calculation using GOST P 54993 gives underrated energy efficiency classes. This can lead to interdiction of export for certain light sources and luminaires, can discredit Russian domestic manufacturer light sources and does not correspond to the rules of the World Trade Organization (WTO).


Author(s):  
A. Radhika ◽  
D. Haritha

Wireless Sensor Networks, have witnessed significant amount of improvement in research across various areas like Routing, Security, Localization, Deployment and above all Energy Efficiency. Congestion is a problem of  importance in resource constrained Wireless Sensor Networks, especially for large networks, where the traffic loads exceed the available capacity of the resources . Sensor nodes are prone to failure and the misbehaviour of these faulty nodes creates further congestion. The resulting effect is a degradation in network performance, additional computation and increased energy consumption, which in turn decreases network lifetime. Hence, the data packet routing algorithm should consider congestion as one of the parameters, in addition to the role of the faulty nodes and not merely energy efficient protocols .Nowadays, the main central point of attraction is the concept of Swarm Intelligence based techniques integration in WSN.  Swarm Intelligence based Computational Swarm Intelligence Techniques have improvised WSN in terms of efficiency, Performance, robustness and scalability. The main objective of this research paper is to propose congestion aware , energy efficient, routing approach that utilizes Ant Colony Optimization, in which faulty nodes are isolated by means of the concept of trust further we compare the performance of various existing routing protocols like AODV, DSDV and DSR routing protocols, ACO Based Routing Protocol  with Trust Based Congestion aware ACO Based Routing in terms of End to End Delay, Packet Delivery Rate, Routing Overhead, Throughput and Energy Efficiency. Simulation based results and data analysis shows that overall TBC-ACO is 150% more efficient in terms of overall performance as compared to other existing routing protocols for Wireless Sensor Networks.


Author(s):  
Андрей Дмитриевич Бухтеев ◽  
Виктория Буянтуевна Бальжиева ◽  
Анна Романовна Тарасова ◽  
Фидан Гасанова ◽  
Светлана Викторовна Агасиева

В данном обзоре приведены проблемы при использовании солнечных элементов и существующие решения этих проблем по повышению энергоэффективности фотоэлементов. Также сравнивается КПД этих солнечных элементов и рассматриваются их особенности. Одним из самых эффективных способов стало применение нанотехнологий. This review presents the problems of using solar cells and existing solutions to these problems to improve the energy efficiency of solar cells. The efficiency of these solar cells is also compared and their features are considered. One of the most effective methods was the use of nanotechnology.


Author(s):  
Alexander D. Pisarev

This article studies the implementation of some well-known principles of information work of biological systems in the input unit of the neuroprocessor, including spike coding of information used in models of neural networks of the latest generation.<br> The development of modern neural network IT gives rise to a number of urgent tasks at the junction of several scientific disciplines. One of them is to create a hardware platform&nbsp;— a neuroprocessor for energy-efficient operation of neural networks. Recently, the development of nanotechnology of the main units of the neuroprocessor relies on combined memristor super-large logical and storage matrices. The matrix topology is built on the principle of maximum integration of programmable links between nodes. This article describes a method for implementing biomorphic neural functionality based on programmable links of a highly integrated 3D logic matrix.<br> This paper focuses on the problem of achieving energy efficiency of the hardware used to model neural networks. The main part analyzes the known facts of the principles of information transfer and processing in biological systems from the point of view of their implementation in the input unit of the neuroprocessor. The author deals with the scheme of an electronic neuron implemented based on elements of a 3D logical matrix. A pulsed method of encoding input information is presented, which most realistically reflects the principle of operation of a sensory biological neural system. The model of an electronic neuron for selecting ranges of technological parameters in a real 3D logic matrix scheme is analyzed. The implementation of disjunctively normal forms is shown, using the logic function in the input unit of a neuroprocessor as an example. The results of modeling fragments of electric circuits with memristors of a 3D logical matrix in programming mode are presented.<br> The author concludes that biomorphic pulse coding of standard digital signals allows achieving a high degree of energy efficiency of the logic elements of the neuroprocessor by reducing the number of valve operations. Energy efficiency makes it possible to overcome the thermal limitation of the scalable technology of three-dimensional layout of elements in memristor crossbars.


Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 695
Author(s):  
Oleg Bazaluk ◽  
Valerii Havrysh ◽  
Mykhailo Fedorchuk ◽  
Vitalii Nitsenko

Global climate changes and fossil fuel reserve depletion are drivers for the search for environmentally friendly renewable energy sources. In Europe, biomass represents the main alternative to fossil fuels. Among energy crops, sorghum is a promising crop for arid regions. The biomass yield and energy efficiency of sorghum (both silage and grain) were studied based on field experiments conducted in Southern Ukraine. The following climate changes were identified: an increase in temperature and a decrease in precipitation. The total energy inputs for sweet sorghum were estimated at 11.256 GJ/ha. The main contributors to the energy inputs are mineral fertilizers (56.99%). The experiment showed that a yield of 40.6 t/ha could be achieved with annual precipitation of 350 mm. The energy efficiency ratio was determined to be 11.18. The total energy inputs for grain sorghum was 16.081 GJ/ha. Its yield (grain) varied from 1.92 to 7.05 t/ha. The energy efficiency ratio of grain sorghum ranged from 2.8 to 16.7.


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