Relay Function Research Articles

A routing strategy with energy optimisation based on community in mobile social networks

The paper proposes an optimal energy efficiency routing strategy minimised network energy consumption with a given delay based on community. Firstly, the expected energy consumption and delay of message delivery are obtained through Markov chain. Then a cost function combined with energy consumption and delay for message deliver is designed. Thus we obtain the optimisation function for delivering message of relay to comprehensive cost. Further, the reward function of relay is given. Finally, the optimal expected reward of optimal relay is achieved using the optimal stopping theory for realising the optimal energy efficiency routing strategy. In simulations, the average energy consumption, the average delay and the average delivery ratio of routing optimisation strategy are compared with other routing strategies in related literatures. The results show the proposed strategy has smaller average energy consumption, smaller average delay and bigger average delivery ratio, and better energy consumption optimisation results can be achieved.

A routing strategy with energy optimisation based on community in mobile social networks

The paper proposes an optimal energy efficiency routing strategy minimised network energy consumption with a given delay based on community. Firstly, the expected energy consumption and delay of message delivery are obtained through Markov chain. Then a cost function combined with energy consumption and delay for message deliver is designed. Thus we obtain the optimisation function for delivering message of relay to comprehensive cost. Further, the reward function of relay is given. Finally, the optimal expected reward of optimal relay is achieved using the optimal stopping theory for realising the optimal energy efficiency routing strategy. In simulations, the average energy consumption, the average delay and the average delivery ratio of routing optimisation strategy are compared with other routing strategies in related literatures. The results show the proposed strategy has smaller average energy consumption, smaller average delay and bigger average delivery ratio, and better energy consumption optimisation results can be achieved.

Integrated Dwt-Differentiation Algorithm for Fault Detection and Relay Coordination in Micro Grid

The Bidirectional flow of current makes it difficult to detect fault in the microgrid. The level of fault current changes continuously with change in load, it leads to selectivity and sensitivity issue of relay. In this paper integrated DWT-differentiation algorithm is proposed for fault detection and relay coordination, the input waveform of fault current is proceed with discrete wavelet transform. Time scale function of DWT used to extract exact feature from signal which helps in further effective analysis. The Optimization function of relay is mainly depends on PSM (plug setting multiplier) and TDS (Time dial span). The Fault current used to calculate this parameter are already analyzed from DWT. Standard 9 bus IEEE system is used as reference. Fault is detected at 21 different locations; initially primary protection is activated and secondary protection operates only if first selected pair of relay fails to operate .The differential algorithm select best pair of backup relay and relay coordination is carried out resulting in reduction of operating Time.

Energy Dynamics in the Brain: Contributions of Astrocytes to Metabolism and pH Homeostasis.

Regulation of metabolism is complex and involves enzymes and membrane transporters, which form networks to support energy dynamics. Lactate, as a metabolic intermediate from glucose or glycogen breakdown, appears to play a major role as additional energetic substrate, which is shuttled between glycolytic and oxidative cells, both under hypoxic and normoxic conditions. Transport of lactate across the cell membrane is mediated by monocarboxylate transporters (MCTs) in cotransport with H+, which is a substrate, a signal and a modulator of metabolic processes. MCTs form a “transport metabolon” with carbonic anhydrases (CAs), which not only provide a rapid equilibrium between CO2, HCO3– and H+, but, in addition, enhances lactate transport, as found in Xenopus oocytes, employed as heterologous expression system, as well as in astrocytes and cancer cells. Functional interactions between different CA isoforms and MCTs have been found to be isoform-specific, independent of the enzyme’s catalytic activity, and they require physical interaction between the proteins. CAs mediate between different states of metabolic acidosis, induced by glycolysis and oxidative phosphorylation, and play a relay function in coupling pH regulation and metabolism. In the brain, metabolic processes in astrocytes appear to be linked to bicarbonate transport and to neuronal activity. Here, we focus on physiological processes of energy dynamics in astrocytes as well as on the transfer of energetic substrates to neurons.

A thyroid hormone network exists in synovial fibroblasts of rheumatoid arthritis and osteoarthritis patients

While patients with rheumatoid arthritis (RA) sometimes demonstrate thyroidal illness, the role of thyroid hormones in inflamed synovial tissue is unknown. This is relevant because thyroid hormones stimulate immunity, and local cells can regulate thyroid hormone levels by deiodinases (DIO). The study followed the hypothesis that elements of a thyroid hormone network exist in synovial tissue. In 12 patients with RA and 32 with osteoarthritis (OA), we used serum, synovial fluid, synovial tissue, and synovial fibroblasts (SF) in order to characterize the local thyroid hormone network using ELISAs, immunohistochemistry, imaging methods, tissue superfusion studies, cell-based ELISAs, flow cytometry, and whole genome expression profiling. Serum/synovial fluid thyroid hormone levels were similar in RA and OA (inclusion criteria: no thyroidal illness). The degradation product termed reverse triiodothyronine (reverse T3) was much lower in serum compared to synovial fluid indicating biodegradation of thyroid hormones in the synovial environment. Superfusion experiments with synovial tissue also demonstrated biodegradation, particularly in RA. Cellular membrane transporters of thyroid hormones, DIOs, and thyroid hormone receptors were present in tissue and SF. Density of cells positive for degrading DIOs were higher in RA than OA. TNF increased protein expression of degrading DIOs in RASF and OASF. Gene expression studies of RASF revealed insignificant gene regulation by bioactive T3. RA and OA synovial tissue/SF show a local thyroid hormone network. Thyroid hormones undergo strong biodegradation in synovium. While bioactive T3 does not influence SF gene expression, SF seem to have a relay function for thyroid hormones.

Control Systems with Vector Relays

The paper presents the evolution of discontinuous control systems starting from a relay with only two output constant values. The relay systems were widely used at the early stage of the feedback control system history. The analysis and design methods for them were developed by Ya. Tsypkin and discussed in his monograph “Theory of relay control systems,” published in 1956. It is shown how a relay function is modified in the so-called variable structure systems, when the relay output cab be equal to one of two continuous state functions. The next step is made in the framework of variable structure systems with vector control. The design procedure for systems with vector relay control relies on selection of a discontinuity surface for each control component. High efficiency of such designed systems results from enforcing sliding modes on the surfaces. Finally, the vector relay unit control is offered. The method is free of the component-wise design and proved to be applicable for infinite-dimensional systems.

Application of the Angular Independent Variable and Its Regularizing Transformation in the Problems of Optimizing Low-Thrust Trajectories

The expediency of using the true longitude or the associated angle as an independent variable in the problems of optimizing multi-revolution, low-thrust trajectories of spacecraft is considered. The auxiliary longitude is introduced, which is used further as a new independent variable instead of time. The advantage of using the auxiliary longitude as an independent variable in the problem of optimizing the trajectories with a fixed angular range and optimum transfer time is demonstrated. The problems of optimizing the trajectories of spacecraft with an ideally controlled, limited-power engine and a limited-thrust engine with a constant exhaust velocity are considered. The possibility of improving the convergence of the methods of solving the problems of optimizing the trajectories with a limited-thrust engine is considered. This improvement is achieved by joint utilization of the smoothing approximation of a relay thrust-switching function and the regularizing transformation of an independent variable, which extends the switching function values in the vicinity of thrust switching instants. Based on the results, the method for solving the problems of optimizing multi-revolution transfers is proposed; the numerical examples of its application are presented.

Apprehending Fault Crises for an Autogenous Nanogrid System: Sustainable Buildings

This paper presents a novel approach for in-house operators to profile and allege fault interferences in a nanogrid system either locally or externally. The proposed hybridized methodology is modeled to apprehend, classify, and locate fault interventions using a heuristic data-driven processing model and a sensing directional flow theorem. Employment of fuzzy control and discrete Fourier transform systems are fused to recompose directional fault relay functionalities. The algorithm is composed of three computational stages: stage 1 quantifies conditional correlate coefficients (COC) based on current and phase angle features sampled at interconnecting feeders, stage 2 engages a fuzzy logic controller to express linguistic truth values against calculated COCs, and stage 3 directs circuit breaker operations advocating post phase-shift aberrations to isolate the faulted region. A nanogrid model inspired by Singapore's Green Mark Building Incentive is developed in the MATLAB environment consisting of a combine heat and power microturbine, a rooftop photovoltaic system, and battery storage units tied to the 22-kVAC distribution network. Analytical results exhibit practicability and decisive settlements in diagnosing various types of fault crises despite low data logging signal-to-noise ratio. Conjointly, engagements of circuit breakers have rendered accurate switching operations toward isolating faulted regions.

SISTEM KONTROL OTOMATIS PENGISIAN CAIRAN DAN PENUTUP BOTOL MENGGUNAKAN ARDUINO UNO Rev 1.3

The system design test results are obtained that when the sensor detects an object with a certain distance, the sensor will issue a signal to the micro which is then forwarded to the charging driver circuit to turn on the relay. The relay functions as a switch or switch that will fill the liquid in the bottle, when the driver is charging on, the process of filling the liquid occurs in the bottle, and the micro filling process issues a signal in the active motor driver circuit. The conveyor driver is active after giving a signal from Arduino Uno, the conveyor will stop after the sensor detects a bottle then stops, and the micro sends a signal to turn the motor driver down on the bottle cap to close the bottle on. When the bottle closing process is complete the motor driver backs up actively moving the road conveyor back. The percentage error of theoretical value and measurement of the difference is small and when filling the liquid in a bottle takes 17 seconds until the bottle is fully filled and by using the micro, the liquid filler on the bottle and the bottle cover can be completed properly.

The Carboxylate Ligand as an Oxide Relay in Catalytic Water Oxidation.

Carboxylate groups have diverse functionalities in ligands of transition metal catalysts. Here we present a conceptually different function of the carboxylates: the oxide relay. It functions by providing an intramolecular nucleophilic oxygen close to the oxo group to facilitate O-O bond formation and at a later stage a remote electrophilic center to facilitate OH- nucleophilic attack. Empirical valence bond-molecular dynamics (EVB-MD) models were generated for key bond forming steps, diffusion coefficients and binding free energies from potential of mean force estimations were calculated from molecular dynamics (MD) simulations, activation free energies of chemical steps were calculated using density functional theory (DFT). The catalyst studied is the extremely active Ru(tda)(py)2 water oxidation catalyst. The combination of simulation methods allowed for estimation of the turnover frequencies, which were within 1 order of magnitude from the experimental results at different pH values. From the calculated reaction rates we find that at low pH the OH- anion nucleophilic attack is the rate-limiting step, which changes at high pH to the O-O bond formation step. Both steps are extremely rapid, and key to the efficiency is the oxide relay functionality of a pendant carboxylate group. We cannot exclude all alternative mechanisms and suggest isotope experiments using 18O-labeled water to support or invalidate the oxide relay mechanism. The functionality was discovered for a ruthenium catalyst, but since there is nothing in the mechanism restricting it to this metal, the oxide relay functionality could open new ways to design the next-generation water oxidation catalysts with improved activity.

Relay optical function and pre-construction results of a Giant Steerable Science Mirror for a thirty meter telescope.

The Giant Steerable Science Mirror (GSSM) is the tertiary mirror system of the Thirty Meter Telescope (TMT) that relays optical beams from the secondary mirror to active instruments on Nasmyth platforms. One of the key technologies involved in GSSM functions is the error budget allocation from the system engineering of TMT. A novel approach of error analysis and allocation with strong adaptability, which is based on normalized Point Source Sensitivity (PSSn), is proposed. The relay optical function including the quality of the wavefront, the rationality of the mechanism, and the stability of the light were achieved based on the proposed method. The experiments validate the proposed method.

Operation Condition Assessment Method and its Practical Implementation for Protection Systems

A well-monitored and reasonable-assessed protection system can lead to the improved operation and reliability of power systems. In this paper, a systematic and efficient operation condition assessment (OCA) method and its practical implementation for protection systems are proposed. Considering the device configuration and information transmission scheme, a protection system operation condition model (PSOCM) is developed. Based on the PSOCM, an OCA method is designed to assess the statuses of devices, information flows, information transmission branches, and relay functions. To verify the effectiveness of the proposed method, a master-substation operation condition assessment system (MS-OCAS), which utilizes real-time monitoring and other raw data, is demonstrated. As shown by the experimental results for a 110 kV IEC 61850-based substation, the proposed method, and system can realize the whole-view OCA of protection systems and can dramatically increase the maintenance efficiency.

Dual-quaternion-based modeling and control for motion tracking of a tumbling target

This paper investigates the problem of controlling a chasing spacecraft (chaser) to track and rendezvous with an uncontrolled target. Based on the actual situation, the torque-free motion of an axisymmetric prolate rigid body is employed to represent the short-term attitude motion of the tumbling target. By taking advantage of the dual quaternion's compact and efficient description of the general rigid motion, the coupled and integrated model of the 6-degree-of-freedom (6-DOF) relative motion between the chaser and the tumbling target is derived in the chaser's body fixed frame after taking full consideration of coordinate transformation. Based on the logarithm of dual quaternion, a sliding mode control (SMC) law based on the exponential reaching law and the continuous relay function is brought forward to address the problem of synchronization control of the 6-DOF relative motion. Simulation results illustrate the effectiveness of the proposed method.

Shunt Capacitor Banks Online Monitoring Using a Superimposed Reactance Method

A new indicating quantity, named superimposed reactance (SR), is presented in this paper to determine failed capacitor elements’ involved phase and number in shunt capacitor banks (SCBs). The proposed quantity is estimated using available measurements to the unbalance protection function of SCBs numerical protective relays. The proposed SR adopts calibrating factors for element failures online monitoring and can provide live report of the number of failed capacitor elements. The proposed method applications are: faster identifying SCBs faulty units, for fuseless and internally fused designs, and planning preventive/scheduled maintenance for all types of unit designs including externally fused units. With integration of these applications into protection intelligent electronic devices that provide captured and time-tagged event records via communication protocols for HMIs and SCADA systems, outage times would be reduced and smart grids reliability would be improved. The developed algorithm supports three different grounding arrangements, Wye-ungrounded, Wye-grounded via a low ratio current transformer, and Wye-grounded via a grounding capacitor at the SCB neutral point. Comprehensive simulation and fault-location sensing in PSCAD and MATLAB have verified the proposed algorithm performance. Advantages of the proposed method reports over conventional unbalance relaying alarms are also demonstrated using a commercial relay test results comparison.

Oblivious Fronthaul-Constrained Relay for a Gaussian Channel

We consider systems in which the transmitter conveys messages to the receiver through a capacity-limited relay station. The channel between the transmitter and the relay station is assumed to be a frequency-selective additive Gaussian noise channel. It is assumed that the transmitter can shape the spectrum and adapt the coding technique so as to optimize performance. The relay operation is oblivious (nomadic transmitters), that is, the specific codebooks used are unknown. We find the reliable information rate that can be achieved with Gaussian signaling in this setting, and to that end, employ Gaussian bottleneck results combined with Shannon’s incremental frequency approach. We also prove that, unlike classical water pouring, the allocated spectrum (power and bit rate) of the optimal solution could frequently be discontinuous. These results can be applied also to a MIMO transmission scheme. We also investigate the case of an entropy-limited relay. We show that the optimal relay function is always deterministic, present lower and upper bounds on the optimal performance (in terms of mutual information), and derive an analytical approximation.

Human neuroepithelial stem cell regional specificity enables spinal cord repair through a relay circuit

Traumatic spinal cord injury results in persistent disability due to disconnection of surviving neural elements. Neural stem cell transplantation has been proposed as a therapeutic option, but optimal cell type and mechanistic aspects remain poorly defined. Here, we describe robust engraftment into lesioned immunodeficient mice of human neuroepithelial stem cells derived from the developing spinal cord and maintained in self-renewing adherent conditions for long periods. Extensive elongation of both graft and host axons occurs. Improved functional recovery after transplantation depends on neural relay function through the grafted neurons, requires the matching of neural identity to the anatomical site of injury, and is accompanied by expression of specific marker proteins. Thus, human neuroepithelial stem cells may provide an anatomically specific relay function for spinal cord injury recovery.

Effect of an additional large disturbance during power swings on the impedance seen by the out-of-step blocking function

This short article analyzes the effect of an additional large disturbance during power swings on the apparent impedances seen by the out-of-step blocking function of a distance relay. An additional large disturbance during power swings can imply a sudden change of the apparent impedance, which should be considered for the setting of out-of-step functions. The goal of this article is to describe this phenomenon, which has not been previously shown in the literature. A Venezuelan case is taken as an example, and the analyzed additional large disturbance is due to the operation of a special protective scheme for the islanding of one specific area. Maximization of the region between concentric characteristics and minimization of correspondent setting time can be useful actions to improve the expected behavior of out-of-step blocking functions. However, these actions are insufficient for the analyzed example, and two non-traditional solutions were proposed. In general, as these additional large disturbances could fortuitously occur when the apparent impedance is near of the trip region, the logical proper solution should be provided by future improvements of the algorithms from relay manufacturers.

Multi-Hop Relay-Aided Underlay D2D Communications for Improving Cellular Coverage Quality

The future wireless networks need to improve spectrum and energy efficiency to satisfy the increasing demand for high data rate. Device-to device (D2D) communications have the ability to address this problem. This paper focuses on the underlay D2D relay function to improve cellular coverage quality. Although there are a few relevant works in this aspect, there is room for further improvement. For example, there is the constraint on the number of relays in a transmission path, which hardly meets the requirement of the cell-edge devices to fully improve their cellular throughput. Also, there is little energy constraint for underlay D2D relay selection, which is difficult to guarantee the service life of underlay D2D relaying links. Furthermore, without careful regulation of transmission power in terms of cellular coverage improvement, it is not conducive to the improvement of spectrum and energy efficiency in this aspect. Therefore, this paper proposes the improved scheme to deal with these problems, which can: 1) improve spectrum efficiency by using underlay spectrum sharing mode and alleviating its weakness (e.g., co-channel interference); 2) enhance comprehensive performance of underlay D2D relaying links by jointly considering multiple Quality-of-Service (QoS) metrics; 3) reduce overhead of relay selection by proposing a greedy algorithm based on a distributed local search; and 4) improve both energy efficiency and convergence time by designing a new power adjustment scheme based on the improved potential game decision algorithm. The theoretical analysis proves the existence of Nash equilibrium, and the simulation results show that the proposed game decision algorithm accelerates convergence and the proposed whole scheme improves cellular coverage quality.

Improvement using frequency relays compared to dynamic and static relays in frequency instability

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

Hardware Impairments Aware Transceiver Design for Full-Duplex Amplify-and-Forward MIMO Relaying

In this paper, we consider a full-duplex (FD) and amplify-and-forward (AF) relay with multiple antennas, where hardware impairments of the FD relay are taken into account. Due to the inter-dependence of the transmit relay power and the residual self-interference in an FD-AF relay, we observe a distortion loop that degrades the system performance when relay dynamic range is not high. In this paper, we analyze the relay function, and an optimization problem is formulated to maximize the signal to distortion-plus-noise ratio under relay and source transmit power constraints. Due to the problem complexity, we propose a gradient-projection-based (GP) algorithm to obtain an optimal solution. Moreover, a non-alternating sub-optimal solution is proposed by assuming a rank-1 relay amplification matrix, and separating the design of the relay process into multiple stages (MuStR1). The proposed MuStR1 method is then enhanced by introducing an alternating update over the optimization variables, denoted as AltMuStR1 algorithm. Numerical simulations show that compared to GP, the proposed (Alt)MuStR1 algorithms significantly reduce the required computational complexity at the expense of a slight performance degradation. Moreover, as the hardware impairments increase, or for a system with a high transmit power, the impact of applying a distortion-aware design is significant.