Journal articles: 'Static relays'

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Touati, Sami, and Hatem Boujemaa. "Static Hybrid Multihop Relaying." International Journal of Computers 15 (April 28, 2021): 48–52. http://dx.doi.org/10.46300/9108.2021.15.7.

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In this work, we propose a new static hybrid mul- tihop relaying protocol where some relays amplify the received signal whereas the remaining ones use Decode and Forward (DF) relaying. The relaying mode in each relay is set using the distance between the different nodes or the average SNR. The exact and asymptotic bit error probabilities are derived. Simulation results are provided in different contexts to compare the performance of hybrid relaying to conventional AF and DF relaying.

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Ch Srihari Varma, T Rama Subba Reddy, and Ch Sai Babu. "Evolution of protective relays in 1-Φ, 25kV, 50Hz railway traction system." International Journal of Engineering Research Updates 2, no. 1 (January 30, 2022): 039–50. http://dx.doi.org/10.53430/ijeru.2022.2.1.0029.

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This paper presents the evolution of protective relays used for the protection of Power Transformer, Over Head Equipment (OHE) and Shunt Capacitor Bank in Indian Railways Electrical Distribution Systems. Initially during electrification Indian Railways adopted 1-Φ, 25KV, 50Hz AC system and electromagnetic relays (EM Relays) for feeder protection of OHE available at that time. But over the period of time with the drastic growth in traffic and sharp increase in demand for more electrical power to heavy goods trains haulage, the above said protective system doesn’t catered the requirements like speed, sensitivity, reliability, post fault data analysis. Hence Indian Railways over the years have undergone a paradigm shift in protective relay schemes. The journey of evolution from EM relays and static relays to the latest state of art integrated Numerical relays which were approved by RDSO are dealt here.

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Bota, Sebastià A., Jaume Verd, Xavier Gili, Joan Barceló, Gabriel Torrens, Rafel Perelló, Tomeu Alorda, Carol de Benito, and Jaume Segura. "Design Issues for NEM-Relay-Based SRAM Devices." MATEC Web of Conferences 210 (2018): 01005. http://dx.doi.org/10.1051/matecconf/201821001005.

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We analyze the design constraints of six transistor SRAM cells that arise when using nanoelectromechanical relays. Comparisons are performed between a CMOS 6T conventional SRAM cell and various hybrid memory cells built by replacing a selection of MOSFET transistors with NEM relays. Impact on important memory cell parameters such as various reliability metrics like static noise margin and write noise margin and power consumption are evaluated from circuit simulations using a Verilog-A compact model of the nanomechanical relay. We found that the use of relays involve a new challenge in the design of SRAM hybrid devices as the readability and writeability of the resulting cells manifests a strong dependence with the value of the contact resistance of the NEM relay, a parameter that can experience important variations with the continued operation of the device.

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Bailey, B., and D. Jakominich. "Static relays permit enhanced protection." IEEE Industry Applications Magazine 5, no. 2 (1999): 10–17. http://dx.doi.org/10.1109/2943.750387.

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Li, Hao, Yong Ruan, Zheng You, and Zhiqiang Song. "Design and Fabrication of a Novel MEMS Relay with Low Actuation Voltage." Micromachines 11, no. 2 (February 7, 2020): 171. http://dx.doi.org/10.3390/mi11020171.

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Compared with conventional solid-state relays, micro-electro mechanical system (MEMS) relays have the advantages of high isolation, low contact resistance, low power consumption, and abrupt switching characteristics. Nevertheless, the widespread application of MEMS relays has been limited due to the issue of the conflict between low actuation voltages and high device performance. This article presents a novel cantilever MEMS relay with an embedded contact electrode which helps to achieve a low actuation voltage (below 8 V) and high restoring force simultaneously. Meanwhile, the contact resistance is as low as around 0.4 Ω and the reliability is verified. To thoroughly investigate and analyze the novel cantilever MEMS relay, a static theoretical model of the structure was developed. Based on the model, the cantilever MEMS relay was designed and optimized. Then, the relays were fabricated by the bulk-silicon micromachining process based on the silicon–glass anodic bonding technology. Finally, the switching performance of the novel cantilever MEMS relay was measured. Experimental results demonstrate that the proposed MEMS relay has a low actuation voltage below 8 V and high performance, which is in good agreement with the simulation results, and shows significant advantages when compared with previous reports. Therefore, the proposed MEMS relay with an embedded contact electrode is promising in practical applications.

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Yang, Xiao Jing, Fang Yao, Zhi Gang Li, and Xue Bo Feng. "Research on Grey Prediction of Electromagnetic Relay Contact Resistance." Applied Mechanics and Materials 392 (September 2013): 667–71. http://dx.doi.org/10.4028/www.scientific.net/amm.392.667.

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When the relay contacts are switched on the load circuit, contact pairs on-state directly reflects the relays reliability, and it also indirectly reflects machine performance of the relay. Therefore, the static contact resistance is one of the key features of the relays state estimation and failure warning. However, the contact resistance of the relay contact is uncertainty characteristics, small-scale sequence trend model is difficult to obtain an ideal prediction performance, and therefore grey model which based on small-scale sequence for prediction of electrical contact reliability of the relay is drawn on. Using the static contact resistance measurement value of the relay contact resistance as training samples to set up GM (1, 1) model and obtaining development grey numberaand endogenous control grey numberbby least square method, so as to get differential equation of original datas predicted value and then forecast the original data. In order to improve the prediction accuracy and weaken the influence of randomness, sliding smoothing formula to the original data is used to get improved prediction model. By comparing the difference between the accuracy of improved model and not improved model, it concludes that the improved model has possibility and accuracy higher.

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Setiawan, Eko, Septin Puji Astuti, and Handoko Handoko. "REDUCING THE LIKELIHOOD OF ELECTRICAL POWER-RELATED DISASTERS: A FUZZY MCDM APPROACH." Simetris: Jurnal Teknik Mesin, Elektro dan Ilmu Komputer 9, no. 1 (April 1, 2018): 679–86. http://dx.doi.org/10.24176/simet.v9i1.1761.

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Many of disasters are related to electrical power systems. They affect human life and economy. In order to reduce the negative impacts caused by the failure of electricity power system due to disasters and to create a robust electrical power system, selecting the best relay of electricity power is a must. This study identified the best protective relay of electrical power systems of PLN in Surakarta region by applying analytic hierarchy process (AHP), one of MCDM approaches, combined with fuzzy logic. Extent analysis approach was implemented to derive priorities of various criteria, sub-criteria and alternatives. Three relays being considered in the selection process are electromagnetic relay, digital relay and static relay. Four criteria in this study are techno-economy, fault frequency, protection of transmission line and advantage of relay over others. Meanwhile, five sub-criteria for each criterion are reliability, selectivity, sensitivity, working speed and efficient. Based on the criteria and sub-criteria, it can be inferred that in terms of four working areas of PLN management in Surakarta region, digital relay is seen as the best choice of relays.

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Rasaei, A., and A. Emamhosseini. "Improvement using frequency relays compared to dynamic and static relays in frequency instability." Bangladesh Journal of Scientific and Industrial Research 52, no. 4 (December 6, 2017): 289–94. http://dx.doi.org/10.3329/bjsir.v52i4.34770.

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Nowadays a smarter, more diverse and robust electricity infrastructure is necessary because power grids form one of the most effective components of the infrastructure on which modern society depends on. The stability of an electrical grid is very important for suppliers and consumers. Frequency variations cause instability in the electricity grid. There will be so many problems such as overproduction, overloading, and etc. which have irreversible effects on suppliers and consumers. Balancing the isolated systems in terms of production and consumption, and also using the frequency relays in power grids are useful ways to solve these problems. Due to the importance of frequency relays in proportion than dynamic and static relays, designing and optimizing the frequency relays are very important to guarantee the stability of the electrical grid. The frequency relays can be used in a different network with different charges. The frequency relays have two parts, namely measurement, and detection which undertake separate tasks. In this paper, we investigated the function of frequency relays. We also simulated and analyzed the aforementioned issues. The simulation provides a comparison of grid charge variations and nominal frequency in a state of disarray and approach to the ideal state. Some blocks have been used for counting the frequency in this simulation which most notably, included a block of frequency measurement and another block that has the protection duty.Bangladesh J. Sci. Ind. Res. 52(4), 289-294, 2017

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Ksiazkiewicz, Andrzej, Grzegorz Dombek, Karol Nowak, and Jerzy Janiszewski. "Electrodynamic Contact Bounce Induced by Fault Current in Low-Voltage Relays." Energies 12, no. 20 (October 16, 2019): 3926. http://dx.doi.org/10.3390/en12203926.

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Due to fault currents occurring in electrical installations, high electromagnetic force values may be induced in current paths of low-voltage electromagnetic relays. This force may lead to an electromagnetic bounce that will further result in an electric arc ignition between contacts, and under some circumstances, it will result in contact welding. For the proper exploitation of relays, the threshold value of the maximum current, and thus the electrodynamic force, should be known. This force depends on several factors, including: contact materials, dimensions of relay current paths, relay electromagnetic coil, etc. This paper presents the results of calculations and an experiment on electromagnetic forces, which cover these factors. A static closing force, acting on the contacts, and the fault current were measured. As a result, values of the force and current threshold were obtained, which inform when an electrodynamic bounce may occur. The obtained result may be used in designing contact rivets and relay current paths together with the selection of adequate fault protection devices.

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LIPMAN, JUSTIN, PAUL BOUSTEAD, and JOHN JUDGE. "NEIGHBOR AWARE ADAPTIVE POWER FLOODING (NAAP) IN MOBILE AD HOC NETWORKS." International Journal of Foundations of Computer Science 14, no. 02 (April 2003): 237–52. http://dx.doi.org/10.1142/s0129054103001704.

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This paper introduces Neighbor Aware Adaptive Power flooding, an optimized flooding mechanism used in mobile ad hoc networks (MANETS) that employs several mechanisms (neighbor coverage, power control, neighbor awareness and local optimization) to limit the broadcast storm problem, reduce duplicate packet reception and lower power consumption in both transmission and reception. Upon receiving an optimized broadcast, a relay determines a new set of possible relays (to continue the flood) based upon local neighbor information and the previous optimized broadcast. Additionally, neighboring relays only consider the shared neighbors they are closest to. A relay may perform local optimization (to reduce power consumption and isolate broadcasts) by substituting one high power broadcast with two or more low power broadcasts, thereby introducing additional hops, We show that compared to blind flooding and multipoint relaying, NAAP in a static environment greatly reduces the problems associated with the broadcast storm problem, duplicate packet reception and power consumption.

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Lin, LP, YY Qiu, and YY Peng. "Design of the Integrated Performance Testing Device for Electromagnetic and Static Relays Based on Single Chip Microcomputer." Journal of Physics: Conference Series 2476, no. 1 (April 1, 2023): 012092. http://dx.doi.org/10.1088/1742-6596/2476/1/012092.

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Abstract In order to improve the action performance of the relay, this paper designs an electromagnetic static relay comprehensive performance testing device based on MCU. First of all, a master-slave design structure is proposed, which is composed of a low-power, high-performance Cortex-M3 core high-speed microcontroller. Then, the one-time test model and control logic suitable for testing coil resistance, action/return voltage, coil action power, action/recovery time, contact resistance and working power consumption of AC and DC relays are emphatically introduced. Finally, through experiment testing in substations and power plants, the intelligence, rapidity and integrity of the device are verified.

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Chiba, T., H. Kudo, A. Watanabe, M. Goto, M. Kido, and K. Seo. "Development of custom LSIs for protective relays and their evolution to new static relays." IEEE Transactions on Power Delivery 3, no. 1 (1988): 130–37. http://dx.doi.org/10.1109/61.4238.

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Baker, D. S., B. G. Bailey, B. Bridger, C. J. Cook, K. R. Cooper, J. S. Dudor, J. D. Fischer, et al. "Application considerations of static overcurrent relays: a working group report." IEEE Transactions on Industry Applications 33, no. 6 (1997): 1493–500. http://dx.doi.org/10.1109/28.649961.

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Khoa, Ngo, and Doan Tung. "Locating Fault on Transmission Line with Static Var Compensator Based on Phasor Measurement Unit." Energies 11, no. 9 (September 9, 2018): 2380. http://dx.doi.org/10.3390/en11092380.

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The flexible alternating current transmission systems (FACTS) have been widely used in modern power systems. Because of the presence of the FACTS devices, distance relays in transmission lines may inaccurately locate fault locations. Therefore, it is significant to find a mechanism for locating fault in transmission lines connected to FACTS in which a static var compensator (SVC) is investigated in this work. Based on the development of a phasor measurement unit (PMU) with global positioning system (GPS), this paper proposes a new method for calculating apparent impedance seen by the distance relay location while a short-circuit fault occurs in a transmission line connected the SVC to the midpoint of the line. According to the method, sampled voltage and current measurement at the relay and SVC locations are synchronized using PMUs and the synchronized measurements are then used to calculate a new apparent impedance and to locate the fault location in the line. The method in this paper has the capability for fast calculation and it also has the robustness for identifying different fault types in power systems. Matlab/Simulink software is applied to simulate the study results and to evaluate the correctness of the modeling and effectiveness of the proposed method for locating fault in this paper.

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Vaithilingam, C., Himani Jain, Medha Ojha, Meghna Singh, and J. Vijay Joseph Samuel. "Adaptive protection scheme for microgrids." International Journal of Engineering & Technology 7, no. 2.31 (May 29, 2018): 37. http://dx.doi.org/10.14419/ijet.v7i2.31.13393.

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Micro grids are gaining attention to become an integral part of traditional power system, due to their numerous technical benefits and their ability to improve power system reliability.Voltage regulation, reduction in Transmission and distribution losses, reduction in the need for transmission capacity addition etc are the few technical benefits of micrgrids with renewable energy sources. However, a protection scheme that suits a conventional power system will require a major revamp if micro grids need to be interfaced. The power generations of each renewable source, mode of operation of microgrids are the few important factors to be considered to fix the relay settings. The conventional over current protection scheme faces selectivity and sensitivity issues during the grid faults and the microgrid faults, since the fault current level is different in both the cases. Hence, electro mechanical and static relays may not be suitable for the protection of power systems with microgrids. The processor based relays with augmented intelligence, that is, a relaying scheme which can act according to the operating condition need to be developed. This paper proposes an adaptive protection scheme for power systems with microgrids. The proposed method in this paper is tested with a hardware prototype resembles the actual microgrid setup.

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Zhang, Xiaomei, and Guohong Cao. "Proactively Placing Static Relays With Social-Link Awareness in Mobile Social Networks." IEEE Transactions on Vehicular Technology 68, no. 2 (February 2019): 1903–15. http://dx.doi.org/10.1109/tvt.2018.2889228.

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Pei, Yuanteng, and Matt W. Mutka. "STARS: Static Relays for Remote Sensing in Multirobot Real-Time Search and Monitoring." IEEE Transactions on Parallel and Distributed Systems 24, no. 10 (October 2013): 2079–89. http://dx.doi.org/10.1109/tpds.2012.299.

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Aguilar, Carlos, and Ayoze Socorro. "Busbar earthfault protection methods on LCI static starter turbogenerators using generator protection relays." Journal of Engineering 2018, no. 15 (October 1, 2018): 1084–86. http://dx.doi.org/10.1049/joe.2018.0265.

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Lasiyono, M. Munawir. "Setting Relai Differensial Pada Transformator Daya 150kv Gardu Induk Pondok Indah Menggunakan Protocol Communications Modbus." ETNIK: Jurnal Ekonomi dan Teknik 1, no. 3 (December 20, 2021): 204–13. http://dx.doi.org/10.54543/etnik.v1i3.25.

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Transformers in power systems require different types of protection.This protection is provided by various types of relays, bothelectromagnetic and static. In general, transformer protection servesto protect the transformer in the event of a disturbance, so that thetransformer can be avoided from damage. The relay that will be usedto protect the transformer is a differential relay. This relay workswhen there is a difference in the current of the Current Transformer[CT] on the primary and secondary sides. If the fault occurs outsidethe protection zone, the relay will not work. The method used in thisresearch is R&D (Research and Development), namely research anddevelopment methods, research and development methods areresearch methods used to produce certain products, and test theeffectiveness of these products. An evaluation of the differentialrelay setting on a 150kV power transformer has been carried out atthe Pondok Indah Substation using the Modbus CommunicationsProtocol, where the settings in the field and from the results ofcalculations using the Micom 632 differential relay are obtained: forthe calculation results of Idiff = 0.39 and Idiff max = 8.07 while theactual setting in the field is Idiff = 0.3 and Idiff max = 8. Thedifference in value between the actual setting and the calculationresults is Idiff by 30%, and Idiff max 0.87% is still within theallowed interval . Setting using the modbus communicationsprotocol has advantages, including reducing wiring, makingtroubleshooting or interference easier, reducing the possibility ofhuman-error errors in the configuration process, and making it easyto make changes.

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Sheikh, Aafreen S. "Reactive Power Compensation and Power Factor Correction by using Static VAR Compensator (SVC)." International Journal for Research in Applied Science and Engineering Technology 9, no. VI (June 30, 2021): 4034–36. http://dx.doi.org/10.22214/ijraset.2021.36061.

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In this paper, a reactive power compensation system using static VAR compensator is presented. To confine on system stability and reliability, the reactive power compensation is the fundamental way forflexible AC transmission systems (FACTS). The variations of reactive power have an effect on thegenerating units, lines, circuit breakers, transformers, relays, and isolators. It can also cause effective voltage sags and increase losses. In the proposed system, the lead time between voltage pulse and curren pulse is measured and fed to the interrupt pins of the microcontroller where the program takes over to bring the shunt capacitors to the circuit to get the reactive power compensated. Back-to-back SCRs interfaced through optical isolation from the microcontroller are used in parallel for controlling the capacitor.

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Jumaa, Noor, Abbas Allawy, and Mustafa Shubbar. "Modelling and optimising a new hybrid ad-hoc network cooperation strategy performance using genetic algorithm." Serbian Journal of Electrical Engineering 18, no. 2 (2021): 193–210. http://dx.doi.org/10.2298/sjee2102193j.

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The lifetime of an ad-hoc network depends on a mobile device?s limited battery capacity. In ad-hoc multi-hop communication, source nodes use intermediate nodes as a relay to communicate with remote destinations. As cooperation between nodes is restrained by their battery resources, it might not be in their best interests to always accept relay requests. Therefore, if all nodes decide how much energy to spend for relaying, selfish or non-cooperative nodes reduce cooperation by rejecting to forward packets to others, thereby leading to a dramatic drop in the network?s throughput. Three strategies have been founded to solve this problem: tit-for-tat, live-and-let-live, and selective drop. This research explored a new strategy in ad-hoc cooperation which resulted from the combination of the live-and-let-live and selective drop strategies. This new strategy is based on the suggestion to select fewer hops with a low drop percentage and sufficient power to stay alive after forwarding the data packets towards the destination or other relays at the route path. We used a genetic algorithm (GA) to optimise the cooperative problem. Moreover, the fitness equation of the GA population was designed according to the mixing of the two strategies, which resulted in a new optimized hybrid dynamic-static cooperation.

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Liu, Xuewen, Shuman Huang, Kaisa Zhang, Saidiwaerdi Maimaiti, Gang Chuai, Weidong Gao, Xiangyu Chen, Yijian Hou, and Peiliang Zuo. "Joint Resource Allocation and Drones Relay Selection for Large-Scale D2D Communication Underlaying Hybrid VLC/RF IoT Systems." Drones 7, no. 9 (September 19, 2023): 589. http://dx.doi.org/10.3390/drones7090589.

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Relay-aided Device-to-Device (D2D) communication combining visible light communication (VLC) with radio frequency (RF) is a promising paradigm in the internet of things (IoT). Static relay limits the flexibility and maintaining connectivity of relays in Hybrid VLC/RF IoT systems. By using a drone as a relay station, it is possible to avoid obstacles such as buildings and to communicate in a line-of-sight (LoS) environment, which naturally aligns with the requirement of VLC Systems. To further support the application of VLC in the IoT, subject to the challenges imposed by the constrained coverage, the lack of flexibility, poor reliability, and connectivity, drone relay-aided D2D communication appears on the horizon and can be cost-effectively deployed for the large-scale IoT. This paper proposes a joint resource allocation and drones relay selection scheme, aiming to maximize the D2D system sum rate while ensuring the quality of service (QoS) requirements for cellular users (CUs) and D2D users (DUs). First, we construct a two-phase coalitional game to tackle the resource allocation problem, which exploits the combination of VLC and RF, as well as incorporates a greedy strategy. After that, a distributed cooperative multi-agent reinforcement learning (MARL) algorithm, called WoLF policy hill-climbing (WoLF-PHC), is proposed to address the drones relay selection problem. Moreover, to further reduce the computational complexity, we propose a lightweight neighbor–agent-based WoLF-PHC algorithm, which only utilizes historical information of neighboring DUs. Finally, we provide an in-depth theoretical analysis of the proposed schemes in terms of complexity and signaling overhead. Simulation results illustrate that the proposed schemes can effectively improve the system performance in terms of the sum rate and outage probability with respect to other outstanding algorithms.

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Polajžer, B., A. Trupej, and P. Xenos. "Analysis of the Impact of a Modular SSSC on the Operation of Transmission Line Protection Relays using a Hardware-In-the-Loop Configuration." Renewable Energy and Power Quality Journal 20 (September 2022): 629–34. http://dx.doi.org/10.24084/repqj20.386.

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This paper evaluates the impact of a modular Static Synchronous Series Compensator (m-SSSC) on the operation of communication-assisted line distance and differential protection relays. The m-SSSC system incorporates an over-current protection feature to trigger the bypass mode of operation during grid faults. A case study is analyzed for a 220 kV transmission line and an m-SSSC with a reactive power rating of 80 MVAr per phase using a Hardware-In-the-Loop configuration. The obtained results show the impact of the m-SSSC system on the distance protection operation during some cases of high resistive faults. The differential protection operation was not affected by the mSSSC.

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Jin, Dong-Sup, Jong-Seon No, and Dong-Joon Shin. "New interference alignment schemes with full and half-duplex relays for the quasi-static X channel." IET Communications 8, no. 3 (February 13, 2014): 351–59. http://dx.doi.org/10.1049/iet-com.2013.0178.

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Huang, Ya-Xin, Xiao-Di Zhang, Fei Yu, Yong-Qing Wei, and Hai-Long Zhang. "Networking of Smart Meters Based on Time-Varying Feature of Low-Voltage Power Line Channel in Microgrid." Complexity 2021 (January 29, 2021): 1–16. http://dx.doi.org/10.1155/2021/6635588.

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In order to manage the electricity consumption information of microgrid users, the reliability of electricity information collection is studied in this paper. The normal communication between the acquisition terminal and the smart meter is a key factor affecting the accurate collection of power information; it is the basis for ensuring the operation of the microgrid as well. In order to improve the reliability of the low power line communication between the acquisition terminal and smart meters, this article first uses the static networking method to layer the smart meters and select relays from them and then select the optimal communication path based on integrating communication quality and relay forwarding number dynamically, which could avoid the signal conflict problem caused by simultaneous communication. Finally, by analyzing the influence of the time-varying power line channel on the smart meter communication, a method based on the integrated communication quality and the relay number to consider the time variability of low power line communication is proposed. Choosing the optimal path of the smart meters when the communication path is abnormal can not only establish a new communication path for communication in time, but also avoid communication failures caused by the time-varying channel. Through MATLAB simulation, the time-varying dynamic network of the power line channel is introduced in this paper, which improves the reliability of the smart meter communication and has certain guiding significance for the actual smart meter network construction in microgrid.

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Li, Kai, Ning Lu, Jingjing Zheng, Pei Zhang, Wei Ni, and Eduardo Tovar. "BloothAir." ACM Transactions on Cyber-Physical Systems 5, no. 3 (July 2021): 1–22. http://dx.doi.org/10.1145/3448254.

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Thanks to flexible deployment and excellent maneuverability, autonomous drones have been recently considered as an effective means to act as aerial data relays for wireless ground devices with limited or no cellular infrastructure, e.g., smart farming in a remote area. Due to the broadcast nature of wireless channels, data communications between the drones and the ground devices are vulnerable to eavesdropping attacks. This article develops BloothAir, which is a secure multi-hop aerial relay system based on Bluetooth Low Energy ( BLE ) connected autonomous drones. For encrypting the BLE communications in BloothAir, a channel-based secret key generation is proposed, where received signal strength at the drones and the ground devices is quantized to generate the secret keys. Moreover, a dynamic programming-based channel quantization scheme is studied to minimize the secret key bit mismatch rate of the drones and the ground devices by recursively adjusting the quantization intervals. To validate the design of BloothAir, we build a multi-hop aerial relay testbed by using the MX400 drone platform and the Gust radio transceiver, which is a new lightweight onboard BLE communicator specially developed for the drone. Extensive real-world experiments demonstrate that the BloothAir system achieves a significantly lower secret key bit mismatch rate than the key generation benchmarks, which use the static quantization intervals. In addition, the high randomness of the generated secret keys is verified by the standard NIST test, thereby effectively protecting the BLE communications in BloothAir from the eavesdropping attacks.

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Ngandu, Kabeya, Khmaies Ouahada, and Suvendi Rimer. "Smart Meter Data Collection Using Public Taxis." Sensors 18, no. 7 (July 16, 2018): 2304. http://dx.doi.org/10.3390/s18072304.

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The advent of wireless sensor networks (WSN) has opened up an array of applications. Due to the ad-hoc nature of WSN and the small size of wireless nodes, multiple system configurations are possible. In order to collect data from WSN, some systems utilize static nodes with a network setup that consists of multiple relays to facilitate the dissemination of data to a gateway. Other WSN architectures consist of a mixture of static and mobile nodes. Mobile nodes are able to collect data from the WSN when in close proximity to a static node. Such nodes are referred to as data mules. Data mules presents multiple advantages including the improvement of the network life as communication usually takes place via a single hop. In order to collect smart meter data, we propose the usage of mini-bus taxis carrying a data collector node as an alternative to traditional GSM models where data collected is directly uploaded from a data concentrator to a server. Using the vast network of mini-bus taxis in South Africa, data collection in areas lacking GSM network will be possible. This paper will attempt to present all the relevant parameters required for such data collection scheme to be successful.

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ANDREEV, SERGEI A. "CONTROLLED ELECTRIC DOUBLE-MOTOR DRIVE OF LOW-POWER CIRCULAR SAWS." Agricultural engineering, no. 1 (2022): 65–71. http://dx.doi.org/10.26897/2687-1149-2022-1-65-71.

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Using low-power circular saws in farm workshops is characterized by the variety of operating modes determined by the nature of cuts. To increase the efficiency of circular saws when cross-cutting wood, use can be made of inertial energy storage devices in the form of flywheels. However, with longitudinal cuts, the kinetic energy of the flywheels quickly dries up, and it takes a long time to replenish it. To reduce the restoration time of the required saw disk speed, the authors propose using the rotor of an auxiliary electric motor as a flywheel. The regulator automatically controls the auxiliary electric motor according to the current value in the power supply circuit of the main electric motor. To avoid self-oscillations of an unacceptably high frequency, the static characteristic of the regulator must contain a section with aт ambiguity zone. This is achieved by using a Ladder Diagram and a logic gate or a microprocessor. The relay-contact circuit includes five electromagnetic relays, a time relay, and two magnetic starters. The time relay aims to eliminate false alarms by ensuring that the regulator is not susceptible to inrush current. To implement the algorithm for controlling an auxiliary electric motor, it is possible to use the logical elements “AND” and “OR,” included according to the proposed scheme. An effective measure of increasing the reliability and reducing the regulator size is the use of the ARDUINO microprocessor together with semistors installed in the power circuits of circular saw motors. The controlled double-motor electric drive of the low-power circular saw reduces energy consumption when cross-cutting wood and improves working conditions and productivity when ripping.

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Shakir, Hasan Awni, Ravie Chandren Muniyandi, and Zulkarnain MD Ali. "Enhancement of Energy Control Routing Protocol for Mobile Ad Hoc Network Based on Hybrid Particle Swarm Optimization with Ant Colony-based Energy Control Routing." Indonesian Journal of Electrical Engineering and Computer Science 8, no. 2 (November 1, 2017): 308. http://dx.doi.org/10.11591/ijeecs.v8.i2.pp308-314.

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MANET is an autonomous collection of distributed mobile nodes. Every node in a MANET works as a source and a sink and that relays packets for other nodes. The key features of a MANET include dynamic network topology, distributed network nature, multi-hop communication, limited bandwidth, and limited energy constraints. Given that the battery of the nodes is limited, the energy of the nodes and the lifetime of network is a critical problem in MANETs. Moreover, nodes maintain static or less movement after being deployed. The energy of the MANET nodes cannot be recharged, which leads to dead nodes. This study improves the energy cost for the ACECR and boosts advancement through its contributions. Areas in the ad hoc network where much work is needed are discussed. This study only explored the impact of PSO on ACECR. Results indicate that ACECR- PSO performed better than the other protocols in terms of balanced energy consumption and extended network lifetime.

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Bolandi, Tohid Ghanizadeh, Vahid Talavat, and Javad Morsali. "Online vulnerability assessment of Zone-3 distance relays against static load Encroachment: A novel approach based on fault chain theory." International Journal of Electrical Power & Energy Systems 151 (September 2023): 109183. http://dx.doi.org/10.1016/j.ijepes.2023.109183.

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Kaur, Ravneet Pal, and Maninder Singh. "An Energy Efficient Routing Scheme for Mobile Wireless Sensor Network with Mobile Sink." International Journal of Advanced Research in Computer Science and Software Engineering 7, no. 8 (August 30, 2017): 100. http://dx.doi.org/10.23956/ijarcsse.v7i8.32.

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In wireless sensor network, the sensor nodes find the route towards the sink to transmit the sensory information such as temperature, pressure etc of a particular area. The sensor nodes transmit the data directly to sink or it relays the data through neighbor nodes using single or multi-hop links. Each time when nodes send their data to static sink, the data is passed through the nearer nodes of sink to it. As soon as the nodes near to the sink become dead, the entire network will be useless as there will be no communication to the sink node. So, to conserve the energy we use mobile sink approach. Thus with the inclusion of mobile sink in WSN, new paradigm called mobile wireless sensor network came into existence. In this paper, to conserve energy and to perform energy efficient routing, we have proposed chain-based energy efficient routing scheme for mobile wireless sensor network (CB-EERM)which is using mobile sink and media access approach where sink moves from one position to another position in sensor field and sojourn at a particular location to collect the whole aggregated data from the various leader(aggregator)nodes in chain using media access approach. The proposed mobile scheme CB-EERM is validated through simulation and compared with traditional static approach using metrics such as energy consumption, throughput, delay and packet delivery ratio where proposed approach outperforms the existing scheme.

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Bigharaz, Mohammad Hossein, Mehdi Amiri Dehcheshmeh, Hadi Givi, and Štěpán Hubálovský. "Multi-Objective Real-Time Tuning of SVC Used in Electrified Traction Systems." Sensors 22, no. 4 (February 17, 2022): 1584. http://dx.doi.org/10.3390/s22041584.

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Electric train system is a very large load for the power network. This load consumes a large amount of reactive power. In addition, it causes a massive unbalance to the network, which results in many problems such as voltage drops, high transmission losses, reduction in the transformer output ability, negative sequence current, mal-operation of protective relays, etc. In this paper, a novel real-time optimization approach is presented to adjust the static VAR compensator (SVC) for the traction system to realize two objectives; current unbalance reduction and reactive power compensation. A multi-objective optimization technique entitled non-dominated sorting genetic algorithm (NSGA-II) is used to fulfill the regarded objectives simultaneously. A comprehensive simulator has been designed for electric train network modeling that is able to adjust the parameters of SVC in an optimum manner at any time and under any circumstances. The results illustrate that the provided method can efficiently reduce the unbalancing in current as well as supply the demanded reactive power with acceptable precision.

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Barlow, Steven M., and Paul T. Bradford. "Comparison of Perioral Reflex Modulation in the Upper and Lower Lip." Journal of Speech, Language, and Hearing Research 39, no. 1 (February 1996): 55–75. http://dx.doi.org/10.1044/jshr.3901.55.

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The spatiotemporal organization and specificity of the mechanically evoked, short latency penoral response (R1) was sampled from a group of normal adult humans. Perioral reflex activity was sampled during passive and active static force conditions in the presence of servo-controlled mechanical inputs to lip vermilion. Results confirmed that the sensorimotor apparatus of the lower face is very responsive to low level mechanical inputs and highly dependent on several factors including input site (upper vs. lower lip), amount of glabrous tissue stimulated (contactor array size), and task dynamics (passive vs. active subject-generated lip force). Arguments are presented to support the idea that several features of the peripheral sensory environment encoded by primary trigeminal afferents, including afferent gain, specificity, locus, and spatial summation, collectively provide inputs vital to higher order sensory relays in the development of a central representation and dynamic conformational map of perioral space. These sensorimotor features encoded by trigeminal afferents are presumed important for motor learning and maintenance of oromotor control during speech, suck, mastication and swallow, and gesture.

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Flaxer, Eli. "Comprehensive Controller for Super Sonic Molecular Beam Gas Chromatograph Mass Spectrometer." Separations 9, no. 12 (December 7, 2022): 417. http://dx.doi.org/10.3390/separations9120417.

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This paper presents a new, comprehensive digital circuit used for the control of a novel gas chromatograph mass spectrometer (GC-MS) interface that is based on supersonic molecular beam (SMB). The circuit includes a Texas Instruments 150 MHz digital signal controller (DSC), high voltage amplifiers for 8 independent channels and 4 independent channels of high resolution pulse width modulation (PWM). The circuit, along with a sophisticated embedded program and a custom made personal computer (PC) application, control all aspects of the interface: smart filament emission-current stabilization, static and scanning mass-dependent ion-source voltages, transfer-line heater proportional integral differential (PID) controls with thermocouple feedbacks, on/off valves, relays and several peripheral device controls that enable the full operation of a turbo-molecular vacuum pump, and of gas flow and pressure controllers. All aspects of this comprehensive controller were successfully tested. The signal for the 450 Th ion (C32H66) for example increased by 123% which is a significant increase. It is obvious that correctly tuned dynamic voltages can guarantee the optimal signal for each mass.

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Ma, Ming, Yuanyuan Yang, and Miao Zhao. "Tour Planning for Mobile Data-Gathering Mechanisms in Wireless Sensor Networks." Vehicular Technology, IEEE Transactions on 62, no. 4 (May 2013): 1472–83. http://dx.doi.org/10.1109/tvt.2012.2229309.

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In this paper, we propose a new data-gathering mechanism for large-scale wireless sensor networks by introducing mobility into the network. A mobile data collector, for convenience called an M-collector in this paper, could be a mobile robot or a vehicle equipped with a powerful transceiver and battery, working like a mobile base station and gathering data while moving through the field. An M-collector starts the data-gathering tour periodically from the static data sink, polls each sensor while traversing its transmission range, then directly collects data from the sensor in single-hop communications, and finally transports the data to the static sink. Since data packets are directly gathered without relays and collisions, the lifetime of sensors is expected to be prolonged. In this paper, we mainly focus on the problem of minimizing the length of each data-gathering tour and refer to this as the single-hop data-gathering problem (SHDGP). We first formalize the SHDGP into a mixed-integer program and then present a heuristic tour-planning algorithm for the case where a single M-collector is employed. For the applications with strict distance/time constraints, we consider utilizing multiple M-collectors and propose a data-gathering algorithm where multiple M-collectors traverse through several shorter subtours concurrently to satisfy the distance/time constraints. Our single-hop mobile data-gathering scheme can improve the scalability and balance the energy consumption among sensors. It can be used in both connected and disconnected networks. Simulation results demonstrate that the proposed data-gathering algorithm can greatly shorten the moving distance of the collectors compared with the covering line approximation algorithm and is close to the optimal algorithm for small networks. In addition, the proposed data-gathering scheme can significantly prolong the network lifetime compared with a network with static data sink or a network in which the mobile collector c- n only move along straight lines.

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Boydell, Victoria. "Creating Lasting Love: An Ethnographic Study of Sexual Pleasure, Intimacy and Contraception." Journal of Positive Sexuality 10, no. 1 (April 26, 2024): 3–7. http://dx.doi.org/10.51681/1.1011.

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Sexual pleasure and intimacy are key reasons why people have sex, yet it remains underexamined in our understanding of how people make decisions about contraception. This paper draws on ethnographic research of the intersections between sexual pleasure, intimacy and contraception among women using specialist contraceptive services in central London. I describe how contraceptive use and choices are intertwined with how women assess intimacy in their sexual relationship, and not solely a desire to avoid pregnancy. How and when women use contraceptives relays their concerns about creating and maintaining pleasure and intimacy in their sexual relationships. Moreover, this ethnographic account illustrates how women draw on various contraceptive methods in their decision making and use them to increase communication and trust, distinguish relationships and potentially enhance sexual pleasure, which is indexical and necessary for enduring intimate connections. Considering intimacy alongside sexual pleasure also allows us to consider the relational dimensions of contraceptive choice and how these are far from static, one-off decisions. These empirical insights into intimacy illustrate that contraceptive choice is both a reflection of the perceived intimacy in a relationship and is also a “practice of intimacy”, particularly when people are navigating the various forms of intimacies available.

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PÎSLARU-DĂNESCU, Lucian, George-Claudiu ZĂRNESCU, and Victor STOICA. "Human Subjects Protection by Monitoring the Stabilized Supply Voltages of the Medical Equipment." Electrotehnica, Electronica, Automatica 70, no. 3 (September 15, 2022): 1–11. http://dx.doi.org/10.46904/eea.22.70.3.1108001.

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This study addresses a sensitive topic, namely how human subjects undergoing medical procedures can be protected by means of medical electrical equipment. A solution to this problem is to monitor the stabilized electrical supply voltages of the medical equipment. The net effect of the proposed protection is the automatic disconnection of the medical equipment from the alternating voltage network supplying the medical equipment. This disconnection must be done without using electrical switching devices that contain electrical contacts that can generate electrical sparks. This is because most of the time the medical equipment is placed in an area where pure oxygen or other combustible gases predominate. Therefore, only static relays are used in this case. The realized electronic module has been tested in the laboratory and is capable of automatic disconnection of any medical equipment from the 230 V~, f = 50 Hz AC power supply in the case of major faults, which can be caused by accidental overvoltage on the electric energy supply lines, accidental overtemperatures, transient overvoltage which are propagated during storms, etc. This study presents the transient phenomena that occur in the immediate vicinity of the monitored voltages range. Finally, a solution for simultaneous monitoring of four electric voltages and/or currents is presented.

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AL-Jumaili, Mustafa Hamid, Hussein M. Haglan, Mohammed K. Mohammed, and Qusay H. Eesee. "An automatic multi-axis solar tracking system in Ramadi city: design and implementation." Indonesian Journal of Electrical Engineering and Computer Science 19, no. 3 (September 1, 2020): 1126. http://dx.doi.org/10.11591/ijeecs.v19.i3.pp1126-1234.

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In this paper, a complete design and implementation of an automatic Multi-Axis solar tracking system has been introduced. The main purpose of this system is to track Sun location and gain the maximum energy output of the solar panels. The system is Multi-axis using microcontroller and photocells to control the direction of the penal, whereas the penal is facing the sun at all times of the day. The system is a combination of hardware and software parts that work concurrently to achieve a precise angular Sun tracking. A Base, Penal Frame, Super Jack Motors, high-efficiency Solar Panel, Arduino Uno microcontroller, Relays, Rechargeable battery, Light Dependent Resistor (LDR) have been used for the system’s hardware part. These hardware parts need a high-level programming code, as a software part, to be embedded in the microcontroller to get an effective and precise solar tracking system. The results of the presented system were compared to a fixed direction system. The results show significant efficiency improvement of 24% over the static one. For a city like Ramadi, which has a high irradiance all over the year, it is very fruitful to use such tracking systems along with photovoltaic installation systems.<div align="center"> </div>

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Qin, Yingsi, Wei-Yu Chen, Matthew O'Toole, and Aswin C. Sankaranarayanan. "Split-Lohmann Multifocal Displays." ACM Transactions on Graphics 42, no. 4 (July 26, 2023): 1–18. http://dx.doi.org/10.1145/3592110.

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This work provides the design of a multifocal display that can create a dense stack of focal planes in a single shot. We achieve this using a novel computational lens that provides spatial selectivity in its focal length, i.e, the lens appears to have different focal lengths across points on a display behind it. This enables a multifocal display via an appropriate selection of the spatially-varying focal length, thereby avoiding time multiplexing techniques that are associated with traditional focus tunable lenses. The idea central to this design is a modification of a Lohmann lens, a focus tunable lens created with two cubic phase plates that translate relative to each other. Using optical relays and a phase spatial light modulator, we replace the physical translation of the cubic plates with an optical one, while simultaneously allowing for different pixels on the display to undergo different amounts of translations and, consequently, different focal lengths. We refer to this design as a Split-Lohmann multifocal display. Split-Lohmann displays provide a large étendue as well as high spatial and depth resolutions; the absence of time multiplexing and the extremely light computational footprint for content processing makes it suitable for video and interactive experiences. Using a lab prototype, we show results over a wide range of static, dynamic, and interactive 3D scenes, showcasing high visual quality over a large working range.

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Soliva, Roger, Frantz Maerten, Jean-Pierre Petit, and Vincent Auzias. "Field evidences for the role of static friction on fracture orientation in extensional relays along strike-slip faults: Comparison with photoelasticity and 3-D numerical modeling." Journal of Structural Geology 32, no. 11 (November 2010): 1721–31. http://dx.doi.org/10.1016/j.jsg.2010.01.008.

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López-Vilos, Nicolás, Claudio Valencia-Cordero, Richard Demo Souza, and Samuel Montejo-Sánchez. "Clustering-Based Energy-Efficient Self-Healing Strategy for WSNs Under Jamming Attacks." Sensors 23, no. 15 (August 3, 2023): 6894. http://dx.doi.org/10.3390/s23156894.

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The Internet of Things (IoT) is a key technology to interconnect the real and digital worlds, enabling the development of smart cities and services. The timely collection of data is essential for IoT services. In scenarios such as agriculture, industry, transportation, public safety, and health, wireless sensor networks (WSNs) play a fundamental role in fulfilling this task. However, WSNs are commonly deployed in sensitive and remote environments, thus facing the challenge of jamming attacks. Therefore, these networks need to have the ability to detect such attacks and adopt countermeasures to guarantee connectivity and operation. In this work, we propose a novel clustering-based self-healing strategy to overcome jamming attacks, in which we denominate fairness cooperation with power allocation (FCPA). The proposed strategy, aware of the presence of the jammer, clusters the network and designates a cluster head that acts as a sink node to collect information from its cluster. Then, the most convenient routes to overcome the jamming are identified and the transmit power is adjusted to the minimum value required to guarantee the reliability of each link. Finally, through the weighted use of the relays, the lifetime of each subnetwork is extended. To show the impact of each capability of FCPA, we compare it with multiple benchmarks that only partially possess these capabilities. In the proposal evaluation, we consider a WSN composed of 64 static nodes distributed in a square area. Meanwhile, to assess the impact of the jamming attack, we consider seven different locations of the attacker. All experiments started with each node’s battery full and stopped after one of these batteries was depleted. In these scenarios, FCPA outperforms all other strategies by more than 50% of the information transmitted, due to the efficient use of relay power, through the weighted balance of cooperative routes. On average, FCPA permits 967,961 kb of information transmitted and 63% of residual energy, as energy efficiency, from all the analyzed scenarios. Additionally, the proposed clustering-based self-healing strategy adapts to the change of jammer location, outperforming the rest of the strategies in terms of information transmitted and energy efficiency in all evaluated scenarios.

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Liu, Zhipeng, Guangyue Lu, Yinghui Ye, and Liqin Shi. "On the Performance of Battery-Assisted PS-SWIPT Enabled DF Relaying." Information 11, no. 3 (March 20, 2020): 165. http://dx.doi.org/10.3390/info11030165.

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Compared with the conventional simultaneous wireless information and power transfer (SWIPT) based relaying with “harvest-then-forward” protocol, the battery-assisted SWIPT relaying is more practical and powerful due to the joint use of the harvested energy and supplementary battery. However, to the best of our knowledge, the performance of a battery-assisted power splitting (PS)-SWIPT decode-and-forward (DF) relay system has not been studied. In this paper, for a given amount of energy from the relay’s battery, we propose to maximize the outage and ergodic capacities by optimizing the static and dynamic PS ratios that rely on statistical and instantaneous channel state information (CSI), respectively, and derive their corresponding outage and ergodic capacities. Computer simulations validate our analytical results and demonstrate the advantages of the dynamic PS over the static PS in terms of the outage and ergodic capacities, as well as the energy efficiency.

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Sung, Su Whan, and Jietae Lee. "Relay feedback method under large static disturbances." Automatica 42, no. 2 (February 2006): 353–56. http://dx.doi.org/10.1016/j.automatica.2005.10.001.

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Fu, Shu, Lian Zhao, Zhou Su, and Xin Jian. "UAV Based Relay for Wireless Sensor Networks in 5G Systems." Sensors 18, no. 8 (July 25, 2018): 2413. http://dx.doi.org/10.3390/s18082413.

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Relay is one of the most significant issues in smart industrial wireless sensor networks (WSN) due to the low transmitting power of sensors. By relay, the signals of sensors can be concentrated at the relay and further transmitted to the base station for decreasing energy consumption in the system. In the past decades, the relay in WSN is generally one super sensor with large transmitting power. However, the placement of the super sensor is static, which leads to the instability of performance in WSN under the time-varying wireless environment. Fortunately, unmanned aerial vehicles (UAV) can provide an effective leverage to improve the environment-adaptation in WSN compared to the static relay in WSN. In this paper, we employ UAV as the relay in WSN, which can move in three-dimensional space to possess a better position to minimize the system power consumption. We use a simple case study to demonstrate the effectiveness of UAV in WSN. Extended simulations are also given to verify the preferable performance of the UAV based relay in WSN.

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Yang, Yuyan. "Automatic Calculation and Simulation of Time-Varying Failure Rate of Digital Relay Protection Device." Mathematical Problems in Engineering 2022 (July 7, 2022): 1–9. http://dx.doi.org/10.1155/2022/8221281.

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Efficiency is an important indicator of risk assessment, but the failure rate changes with time, which makes risk assessment very difficult. Traditional methods often only measure the steady-state and static indicators of relay protection. The traditional method often only measures the steady-state and static indicators of the relay protection, or directly uses the RiskWeibull analysis system to perform reliability analysis on the relevant data. However, this method can only perform quantitative static analysis on the data. Once the system is disturbed, its reliability will be affected. Analysis is not possible. Since the relay protection device has the possibility of malfunction and refusal at the same time, in order to distinguish, the risk is introduced into the reliability evaluation of the relay protection device to achieve the purpose of considering the possibility and consequences of its failure at the same time. Based on the traditional method, this paper proposes a method to calculate the time-varying failure rate of the relay protection device by using the support vector machine model, which improves the influence of hidden risks on the power grid relay protection, and not only realizes the scientific hidden danger evaluation, risk rating. It is of great significance for the development of power grids to evaluate the consequences of failures and to make the transmission lines operate safely and stably.

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Park, Jin Hyun, Su Whan Sung, and In-Beum Lee. "Improved relay auto-tuning with static load disturbance." Automatica 33, no. 4 (April 1997): 711–15. http://dx.doi.org/10.1016/s0005-1098(96)00174-4.

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Sung, Su Whan, Jietae Lee, Dong Hyun Lee, Jong Hun Han, and Young Soo Park. "Two-Channel Relay Feedback Method under Static Disturbances." Industrial & Engineering Chemistry Research 45, no. 12 (June 2006): 4071–74. http://dx.doi.org/10.1021/ie0513393.

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Xu, Hongli, Liusheng Huang, Zhiji Zhang, Gang Liu, and Yindong Zhang. "Cooperative relay assignment for static energy-constrained networks." International Journal of Sensor Networks 11, no. 3 (2012): 192. http://dx.doi.org/10.1504/ijsnet.2012.046335.

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Mishra, Manish Kumar, and Ritesh Kumar Mishra. "Performance Analysis of HSTC Network with Non-Static Terrestrial Nodes in a Fading Environment." Revue d'Intelligence Artificielle 36, no. 3 (June 30, 2022): 363–71. http://dx.doi.org/10.18280/ria.360303.

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In this paper, Hybrid satellite-terrestrial systems (HSTC) are preferred in dynamic type environments with high mobility of nodes due to the performance enhancement features in multiple relay-based selective decode-and-forward (DF) approach. Because of the satellite link, aerial satellite to destination and satellite to relay links, are not the same due to time-selective shadowed Rician fading. Time-selective Rician fading depends on parameters like the angle of elevation of the satellite, the terrestrial relay node, and the node destination links, considered to be distinctively time-selective Nakagami faded. Here, per-frame average symbol error rate (SER) and outage probability are derived in a closed-form expression with consideration of M-ary PSK modulated symbols transmission. After evaluation, it was detected that the system performance is significantly degraded due to the time-varying nature of the links (dynamic environment). After various simulations and calculations, it was established that the error rate of the HSTC is significantly low by increasing the elevation angle of the satellite on the relay point. The performance enhancement can be observed by enhancing the satellite angle at the destination node of user equipment.

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Sung, Su Whan, and Jietae Lee. "Relay Feedback Method under Nonlinearity and Static Disturbance Conditions." Industrial & Engineering Chemistry Research 45, no. 12 (June 2006): 4028–31. http://dx.doi.org/10.1021/ie050822a.

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Journal articles on the topic 'Static relays'

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