Energy Efficient Transmission Research Articles

Peak characteristics of microwave energy transmission in the presence of metal-based particles

The presence of metal-based dielectrics on microwave has been widely studied with the potential in enhancing microwave energy transmission. For the purpose of broadening the microwave energy transmission efficiency, the addition of metal-based dielectrics on microwave process were experimentally investigated, the peak characteristics of energy transmission were analyzed in details. The results showed that the microwave energy transmission achieves the peak values under the match of between particle and microwave frequency. Two sets of matching were obtained in the experiment: a) 70 μm-2475 MHz while the maximum discharge intensity was enhanced by 313.1%; b) 40 μm-2425 MHz while the maximum discharge intensity was enhanced by 546.2%. Metal-based Particles’ dielectric constant and microwave parameters only affect the magnitude of the peak value, not the optimal peak point. Meanwhile, the differential selectivity of frequency and size was initially explained and provided theoretical references for metal-based particles to enhance microwave absorption applications.

Switchable compliant actuator with fast stiffness modulation and energy efficient power transmission

This article presents the design of a switchable compliant actuator (Swi-CA), capable of fast stiffness modulation over a wide range and energy-efficient equilibrium position control. Compliant actuators are designed to have a variable stiffness to generate a restoring force upon displacement. In previous studies, such actuators provided compliance by changing both output stiffness and equilibrium position using a clutch to switch between two modes. We implemented a bifurcation-based switching mechanism to shift between stiffness modulation and equilibrium position control modes via mechanical integration of a variable stiffness spring with a parallel elastic unit without the use of an additional clutch. The distinctive features of the proposed Swi-CA are threefold. First, the central bending of a leaf spring widens the range of modulated stiffness and increases the average stiffness modulation speed. Second, the developed slider-crank mechanism has high power transmission efficiency and fast stiffness modulation. Lastly, an optimized elliptical cam generated negative stiffness during output and enabled switching between the two modes without the use of a controllable clutch. Analytical models and experimental validation of the proposed design clearly demonstrated its advantages for applications requiring fast stiffness modulation and energy-efficient operation, such as some robotics applications.

НАЗЕМНО-БОРТОВІ СИСТЕМИ ВИПРОБУВАНЬ ТА ДІАГНОСТИКИ ВЕРТОЛІТНИХ РЕДУКТОРІВ

The article is an overview and information. An effective direction of operational diagnostics of the most stressed units - gear drives of GTE gearboxes are methods for analyzing vibration signals of the engine casing.The theoretical and experimental substantiation of vibration diagnostics of GTE gears and helicopter gearboxes in-dicates that the main function that characterizes the energy efficiency of torque transmission and is sensitive to the initiation of defects in gear teeth can be considered the deviation of the parameter of the first derivative of the angular velocity of re-coupling of the teeth.The system for collecting and processing flight information is divided into onboard and ground parts. The onboard sub-system in the form of hardware and software systems provides for the collection and preliminary processing of primary infor-mation - vibration signals, synchronization, temperature, etc. It interacts with the standard equipment of the helicopter to obtain information regarding the modes of operation and flight of the helicopter. The on-board subsystem, as a rule, contains vibration sensors, speed sensors and accumulation and pre-processing blocks.The ground subsystem is a set of hardware and software tools that provide automatic express analysis and extended analysis of information recorded on board. The ground subsystem of the diagnostic system can be divided into local and central (support center). The local part is the software for processing the information accumulated during the flight and the database, which are hosted by the organization operating the helicopters.At present, methods are already being used for servicing machines according to the actual state or identifying parts without disassembling them based on vibration diagnostic tests. Their use allows to simultaneously reduce the cost of adjust-ment work and improve their quality, since not only the condition of the parts of the product is checked, but also how they are assembled, whether there are misalignments of bearings or gears during assembly.After the flight, the accumulated data is transferred to the ground subsystem of the operating organization, where post-flight analysis is carried out, processing results are issued and the results are stored in a local database. Further, the processing results are synchronized with the database of the support center to provide information on the technical condition to the devel-opers of helicopters and their units, as well as to operating organizations

Анализ длительно допустимых токов и потерь активной мощности в воздушных линиях электропередачи с учетом климатических факторов

Formulas for calculating continuous admissible currents and active power losses for overhead power transmission lines under conditions of natural and forced convection for insulated and non-insulated conductors are presented. The correct determination of maximum current loads plays an important role in the efficient use of the load capacity of power transmission lines, and the refinement of the calculation of active power losses is the basis for increasing the efficiency of energy transmission. The results obtained can be used in the selection of measures aimed at increasing the capacity of overhead lines and reducing energy losses.

Fine Beam Tracking Using Spatio–Temporal Interpolation in Wireless Power Transfer Systems

The use of transmit beamforming in a radio-frequency wireless power transfer (WPT) system can improve the energy transmission efficiency by concentrating the transmit power in the angle of departure (AoD). Optimal beamforming requires information regarding the AoD or the channel between the transmitter and receiver. A previously proposed WPT system continually estimates the optimal AoD using custom-designed pilot signals, which are known as beam-steered pilot signals and are transmitted periodically at every frame. Herein, we propose a spatio–temporal interpolation technique to improve the accuracy of beam tracking for such a WPT system. Specifically, thin-plate spline interpolation is adopted in the space domain to overcome the limited angular resolution of the beam-steered pilot signals in a three-dimensional channel. In the time domain, polynomial interpolation is performed to track the changing AoD during consecutive frames. Numerical results show that the proposed technique can improve the WPT efficiency as well as the mean square error performance of the beamforming weight vector.

Energy-Efficient Transmission Strategy for Delay Tolerable Services in NOMA-Based Downlink With Two Users

Energy-Efficient Transmission Strategy for Delay Tolerable Services in NOMA-Based Downlink With Two Users

Predictive Model Techniques with Energy Efficiency for IoT-Based Data Transmission in Wireless Sensor Networks

Wireless sensor networks are limited by the vast majority of goods with limited resources. Power consumption, network longevity, throughput, routing, and network security are only a few of the research issues that have not yet been addressed in sensor networks based on the Internet of Things. Prior to becoming widely deployed, sensor networks built on the Internet of Things must overcome a variety of technological obstacles as well as general and specific hazards. In order to address the aforementioned problems, this research sought to improve rogue node detection, reduce packet latency/packet loss, increase throughput, and lengthen network lifetime. Wireless energy harvesting is suggested in the proposed three-layer cluster-based wireless sensor network routing protocol to extend the energy lifespan of the network. For the purpose of recognising and blacklisting risky sensor node behaviour, a three-tier clustering architecture with an integrated security mechanism is suggested. This clustering approach is cost-based, and the sink node selects the cluster and grid heads based on the cost function’s value. With its seemingly endless potential across a wide range of industries, including intelligent transportation, the Internet of Things (IoT) has gained prominence recently. To analyse the nodes and clustering strategies in IoT, the suggested method PSO is applied. A plethora of new services, programmes, electrical devices with integrated sensors, and protocols have been produced as a result of the Internet of Things’ explosive growth in popularity.

Energy efficient data transmission in intelligent transportation system (ITS): Millimeter (mm wave) based routing algorithm for connected vehicles

In the context of the Intelligent Transportation System (ITS), smart urban communication provides both significant potential and formidable problems for linked cars. A high rate of data transfer in vehicular communication is an exciting problem for academics because of the frequent disconnection between linked cars. Recent years have seen the development of millimetre wave (mm Wave) technologies as a solution to the problem of high data transfer rates. In this research, a mm Wave-incorporated routing algorithm and an appropriate channel selection are presented in order to facilitate the transmission of a big quantity of data in an urban setting in an effective manner. Beam formation and alignment, in particular, are responsible for overcoming barriers and finding alternative routes to reach a goal without incurring path loss. Using this stochastic technique, we attempt to transmit data in Line-of-sight (LoS) and non-line-of-sight (NLoS) environments by taking into account a city scenario, narrowing the bandwidth from 90 degrees to 45 degrees, and therefore lowering the risk of signal interference and noise. The suggested system is evaluated for a vehicle range of 20, 30, 40, and 50 with regard to characteristics like Packet Delivery Ratio (PDR), Latency, and throughput.

Joint Communication and Trajectory Design for Intelligent Reflecting Surface Empowered UAV SWIPT Networks

Aiming at the limited battery capacity of widely deployed low-power smart devices in the Internet-of-things (IoT), this paper proposes a novel intelligent reflecting surface (IRS) empowered unmanned aerial vehicle (UAV) simultaneous wireless information and power transfer (SWIPT) network framework, in which IRS is used to reconstruct the wireless channel to enhance the wireless energy transmission efficiency and coverage area of the UAV SWIPT networks. In this paper, we formulate an achievable sum-rate maximization problem by jointly optimizing UAV trajectory, successive interference cancellation (SIC) decoding order, UAV transmit power allocation, power splitting (PS) ratio and IRS reflection coefficient while taking account of user non-orthogonal multiple access (NOMA) and a non-linear energy harvesting model. Due to the coupling of optimization variables, this problem is a complex non-convex optimization problem, and it is challenging to solve it directly. We first transform the problem, and then apply the alternating optimization (AO) algorithm framework to divide the transformed problem into four sub-problems to solve it. Specifically, by applying successive convex approximation (SCA), penalty function method and difference-convex (DC) programming, UAV trajectory, SIC decoding order, UAV transmit power allocation, PS ratio and IRS reflection coefficient are alternately optimized until the convergence is achieved. Numerical simulation results verify the effectiveness of our proposed algorithm compared to other algorithms.

Adaptive Modulation and Coding for Underwater Acoustic Communications Based on Data-Driven Learning Algorithm

With the development of the underwater acoustic (UWA) adaptive communication system, energy-efficient transmission has become a critical topic in underwater acoustic (UWA) communications. Due to the unique characteristics of the underwater environment, the transmitter node will almost always have outdated channel state information (CSI), which results in low energy efficiency. In this paper, we take full advantage of bidirectional links and propose an adaptive modulation and coding (AMC) scheme that aims to maximize the long-term energy efficiency of a single link by jointly scheduling the coding rate, modulation order, and transmission power. Considering the complexity characteristics of UWA channels, we proposed a bit error ratio (BER) estimation method based on deep neural networks (DNN). The proposed network could realize channel estimation, feature extraction, and BER estimation by using a fixed pilot of the feedback link. Then, we design a channel classification method based on the estimated BERs of the modulation and coding scheme (MCS) and further model the UWA channels as a finite-state Markov chain (FSMC) with an unknown transition probability. Thus, we formulate the AMC problem as a Markov Decision Process (MDP) and solve it through a reinforcement learning framework. Considering the large state-action pairs, a double deep Q-network (DDQN) based scheme is proposed. Simulation results demonstrate that the proposed AMC scheme outperforms the fixed MCS with a perfect channel information state, and achieves near-optimal energy efficiency.

Influence of the prestressed layer on spherical transducer in sound radiation performance

To improve the acoustic radiation performance of the spherical transducer, a prestressed layer is formed in the transducer through fiber winding. The influence of the prestressed layer on the transducer is studied from the effects of the radial prestress ([Formula: see text][Formula: see text]) and acoustic impedance, respectively. First, a theoretical estimation of [Formula: see text][Formula: see text] is established with a thin shell approximation of the prestressed layer. Then, the acoustic impedance is measured to evaluate the efficiency of sound energy transmission within the prestressed layer. Further, the ideal effects of [Formula: see text][Formula: see text] on the sound radiation performances of the transducer are analyzed through finite element analysis (FEA). Finally, four spherical transducers are fabricated and tested to investigate their dependence of actual properties on the prestressed layer. The results show that with the growth of [Formula: see text][Formula: see text], the acoustic impedance of the prestressed layer grows, mitigating the enormous impedance mismatch between the piezoelectric ceramic and water, while increasing attenuation of the acoustic energy, resulting in a peak value of the maximum transmitting voltage response ([Formula: see text]) at 1.18 MPa. The maximum drive voltage increases with [Formula: see text][Formula: see text], leading to a steady growth of the maximum transmitting sound level ([Formula: see text]), with a noticeable ascend of 3.9 dB at a 3.44 MPa [Formula: see text][Formula: see text]. This is a strong credibility that the prestressed layer could improve the sound radiation performance of the spherical transducer.

Energy efficient and secure healthcare data transmission in the internet of medical things network

Energy efficient and secure healthcare data transmission in the internet of medical things network

Tunable emission in Dy3+/Eu3+-doped BaLu2Si3O10 trisilicate structure for white light-emitting diode applications

The development of phosphors with high quantum efficiency and excellent thermal stability remains a challenging task for phosphor-converted white light-emitting diodes (w-LEDs). In this work, trisilicate-structured BaLu2Si3O10: Dy3+/Eu3+ (BLSO: Dy3+/Eu3+) series phosphors with stable performance were synthesized by high-temperature solid-phase reaction method. The results show that the Dy3+ monodoped trisilicate phosphor lacks a red component and exhibits cool white light properties, so Eu3+ ions are introduced into the matrix to compensate for the lack of the orange-red emission region. A detailed investigation of the photoluminescence properties of the double-doped phosphor light shows that Eu3+ ions can be well sensitized by Dy3+ under near-UV excitation at 350 nm. According to the Dexter’s energy transfer equation and the Inokuti-Hirayama model, the energy transfer mechanism from Dy3+ to Eu3+ ions was confirmed as the electric dipole-quadrupole interaction, and the CDA value of the interaction parameter for the sample with Eu3+= 0.1 confirmed was 3.128 × 10−54 cm6 s−1, and the energy transmission efficiency could reach 70.09%. By controlling the wavelength of the excitation light and the Eu3+ ion concentration, the CIE coordinates of BLSO can be color adjusted in the white-yellow-orange-red region. The composition-optimized BLSO: Dy3+, Eu3+ phosphor has a CCT of 5622 K. The luminescence intensity of BLSO: 0.04Dy3+, 0.1Eu3+ at 423 K can be maintained at 81.15% of the luminescence intensity at 303 K, which is a satisfactory shows thermal fluorescence stability. From the obtained results, the prepared BLSO: Dy3+/Eu3+ phosphor can be proven as a potential color-tunable luminescent material for w-LEDs.

Stories From China

Superconducting DC cable has the advantages of high current carrying capacity and low loss. It needs an ultra-low temperature to maintain operation. The transmission of clean fuel [such as hydrogen, liquefied natural gas (LNG), ethylene, etc.] in liquid form has the advantages of high energy density and large transmission capacity per unit volume. It also requires an ultra-low temperature environment and thermal insulation. The superconducting electricity-gas integrated DC energy transmission pipeline combines the advantages of the two techniques. The DC energy and liquid fuel are transmitted together with the same refrigeration system and thermal insulation pipe. The superconducting core is cooled by low-temperature fuel, and the refrigeration system and thermal insulation pipe are shared. The superconducting electricity-gas integrated DC energy transmission pipeline improves the overall efficiency of energy transmission and reduces the comprehensive cost [1], [2]. It has the potential to be used in offshore wind power transmission, port power, and other conditions.

Sparse Random Reconstruction of Data Loss With Low Redundancy in Wireless Sensor Networks for Mechanical Vibration Monitoring

Wireless sensor networks (WSNs) for condition monitoring of mechanical equipment have been shown effective for ensuring operational safety and reducing breakdown losses. For battery-supply sensor nodes, energy efficiency for data transmission of mass vibration signals has become a significant challenge. In this article, an efficient low redundant data method is designed and implemented in the WSN nodes for reliable transmission. The proposed method includes two stages. Stage 1 involves the delta-discrete cosine transform (delta-DCT) that reduces the temporal and frequency redundancy of the original data so that the transferred data can be downsized via range coding. In stage 2, the sparse random reconstruction is injected to increase the redundancy of the compressed data to guarantee reliable transmission. Experimental results demonstrate that the original data can be downsized to 50%–55%, and the compression data can be recovered via sparse reconstruction without any data loss.

AN ENERGY- AND DELAY-EFFICIENT TRANSMISSION MECHANISM USING REINFORCEMENT LEARNING IN WIRELESS BODY SENSOR NETWORKS

Clustering mechanism saves energy consumption and prolongs the lifetime of wireless sensor network (WSN). In this paper, we propose an energy and delay efficient transmission mechanism using reinforcement learning in wireless body sensor networks (WBSNs). In the WBSN network, in addition to the efficient energy consumption of the sensor node, when vital information is measured, additional information measured from other sensors must be transmitted to the medical staffs within a limited time so that the medical staff can make a correct decision. The proposed transmission mechanism in this paper considers two novel techniques: a novel CH selection process using reinforcement learning approach and super-frame extension to enhance energy efficiency and network lifetime. Additionally, when a vital signal is measured, it is also proposed to quickly collect relevant information and deliver it to the medical staffs so that the medical staff can make a correct decision. Because of the simulation, the proposed mechanism increased the average network lifetime by 12% and decreased the packet transmission delay by 29.4% compared to the method without reinforcement learning.

Manyetik Rezonans Kuplaj Yöntemiyle Kablosuz Güç Aktarımı Üzerine Literatür Taraması

Today, the widespread use of mobile electronic devices has brought about the advancement of wireless charging technology. Easy charging of these devices with wireless power transfer provides a wide area for users in terms of usability. Energy transmission efficiency is one of the most important parameters in wireless power transmission, which has become one of the popular fields of study recently. Especially in recent years, many studies have been carried out with different techniques on this subject, which brings advantages such as freedom of movement and ease of use by eliminating the problems caused by the cable. A review study on the magnetic resonance coupling method, which enables wireless power transmission with high efficiency at medium distance, is presented. It is aimed that this article will serve as a guide for researchers who will study on wireless power transmission and readers who are interested in this subject, where they can easily access related studies. In our study, firstly, the history of wireless power transfer is given, and then the issues that highlight the magnetic resonance coupling method, one of the wireless power transfer techniques, are included. Then, the basic principle of magnetic resonance coupling method is explained; maximum power transfer, maximum efficiency, alignment problem and its effects on human health are mentioned. Finally, electric vehicles and consumer electronics, biomedical implants, unmanned aerial vehicles and robots, which are the most intense application areas in wireless power transmission, are classified and the studies in these areas are included.

Material design and temperature field simulation analysis of tumor radiofrequency ablation needle

To solve the problems of small one-time ablation range and easy charring of the tissue around the electrode associated with the tumor radiofrequency ablation needle, based on the multiphysical field coupling analysis software COMSOL, the effects of needle material, the number of sub needles and the bending angle of sub needles on the ablation effect of radiofrequency ablation electrode needle were studied. The results show that compared with titanium alloy and stainless steel, nickel titanium alloy has better radiofrequency energy transmission efficiency and it is the best material for electrode needle. The number of sub needles has a great influence on the average necrosis depth and the maximum necrosis diameter. Under the same conditions, the more the number of sub needles, the larger the volume of coagulation necrosis area. The bending angle of the needle has a great effect on the maximum diameter of the coagulated necrotic area, but has little effect on the average necrotic depth. Under the same other conditions, the coagulation necrosis area formed by ablation increased with the increase of the bending angle of the sub needle. For the three needles with bending angles of 60 °, 90 ° and 120 ° analyzed in this paper, the one with bending angle of 120 ° can obtain the largest coagulation necrosis area. In general, the design of nickel titanium alloy with 120 ° bending 8-pin is the optimal. The average depth of radiofrequency ablation necrosis area is 32.40 mm, and the maximum necrosis diameter is 52.65 mm. The above optimized design parameters can provide guidance for the structure and material design of tumor radiofrequency ablation needle.

Autonomous Wireless Technology Detection in Seamless IoT Applications

The ever-increasing use of Internet of Things (IoT) devices results in the implementation of multiple wireless technologies that would not only cater their data rate requirements but also support various applications. To optimize the energy efficiency and security of the wireless transmission, it is imperative to identify the wireless technologies in various IoT implementations. Many of the existing approaches are based on measuring only the receiving signal strength indicator (RSSI). However, such approaches may not work well because of transmit power control and complex channel variations among different wireless technologies. In this article, we propose an autonomous wireless detection scheme that considers multiple distinguishable physical (PHY)-layer settings for real-time identification of wireless technologies for real-time applications. Specifically, the proposed scheme relies on the PHY-layer measurements of the targeted spectrum. Transmission settings, such as bandwidth, carrier frequency, and RSSI are estimated from the raw in-phase and quadrature-phase (I/Q) measurements. In addition, a symbol-level extraction scheme is implemented to extract unique features of modulation settings. These aforementioned features are applied to a machine learning process to identify the received wireless technologies. Compared with raw I/Q measurements, the extracted features are much simplified and, thus, the machine learning classifier can be designed with a simple structure for fast processing on IoT nodes. The proposed schemes are primarily evaluated theoretically, followed by implementing them on a USRP software-defined radio (SDR)-based hardware testbed. The evaluation results demonstrate high accuracy in the real-time detection of different wireless technologies for seamless IoT applications.

Techniques For Reducing Energy And Delay For Data Aggregation In Wireless Sensor Networks

WSN have many applications in different fields like medical, military, health and agriculture, etc., due to its data sensing and gathering abilities to Base station. The main issue in wireless sensor network is energy efficiency under consideration of QOS parameter like delay and security. Many of techniques have been proposed in literature but few work on energy efficient network with QOS. Due to lack of prior research in this area of study, this research will optimize the existing result in manner of giving efficient energy mechanisms and will also provide QOS as well as reduction of delay. It is very important to calculate energy efficiency and data transmission rate in wireless sensor networks because it is widely used in every field of life, especially when we are talking about medical, military and navigation system. After identifying main issues, this research will focus on energy efficiency and delay reduction. But other factors like security and average transmission time is not fully focused.