Conventional Circuit Model Research Articles

Kapasitas Mekanik Panel Komposit Beton Ringan terhadap Beban Siklik

The position of our country is included in the area Ring of Fire, where 90% of earthquakes on earth will occur in this region. Earthquakes in West Sumatra (2009), Mentawai (2010), Lombok and Palu (2018) have claimed more than 10,339 lives and more than 100,000 heavy damage to buildings. Building walls are generally made of brick or adobe, but these two materials have several disadvantages including weight and brittle. As a result of its considerable weight, it will increase the dead load of the structure so that the earthquake load will also increase. Thus, lightweight and clay materials (ductile) will be better if used as earthquake-resistant building walls and the level of risk is lower. Prefabricated sandwich panels produced by PT. BUILDING TECHNOLOGIES INDONESIA within BUKAKA TEKNIK UTAMA Tbk Group. to be a series of cyclic load tested full scale wall constructions. The conventional panel circuit model obtained the behavior of each swaying wall segment as an independent individual panel. Cyclic test results up to drift 12 were obtained with a maximum load of 4.245 kN with a maximum displacement of 106.28 mm compressive direction and a maximum load of 1.425 kN with a maximum displacement of 75.68 mm pulling direction. Deviation behavior is obtained that continues to increase as horizontal loads increase, but not until structural damage occurs in the series of 3 sandwich walls. This condition is a positive thing in the development of buildings with light materials to reduce the magnitude of the earthquake force and minimize damage and casualties.

Quantum Walk Computing: Theory, Implementation, and Application

The classical random walk formalism plays an important role in a wide range of applications. Its quantum counterpart, the quantum walk, is proposed as an important theoretical model for quantum computing. By exploiting quantum effects such as superposition, interference, and entanglement, quantum walks and their variations have been extensively studied for achieving computing power beyond that of classical computing and have been broadly used in designing quantum algorithms for algebraic and optimization problems, graph and network analysis, and quantum Hamiltonian and biochemical process simulations. Moreover, quantum walk models have been proven capable of universal quantum computation. Unlike conventional quantum circuit models, quantum walks provide a feasible path for implementing application-specific quantum computing, particularly in the noisy intermediate-scale quantum era. Recently, remarkable progress has been achieved in implementing a wide variety of quantum walks and quantum walk applications, which demonstrates the great potential of quantum walks. In this review, we provide a thorough summary of quantum walks and quantum walk computing, including theories and characteristics, physical implementations, and applications. We also discuss the challenges facing quantum walk computing, which aims to realize a practical quantum computer in the near future.

Equivalent Magnetic Circuit Model of IPMSM

This paper proposes a magnetic equivalent circuit model for an interior permanent magnet synchronous motor (IPMSM) for the optimal design of the entire system. The computational speed of the proposed model is greater than that of the finite element method (FEM), and the model is suitable for large scale optimization problems. Unlike conventional magnetic circuit models, the proposed model can reflect the dq-axis saliency, which enables analysis under operating conditions using the reluctance torque, which is essential in IPMSMs. In the proposed model, rotor rotation is represented by an AC magnetomotive source, and the saliency characteristics are represented by a multi-phase-q-axis transducer that simulates a q-axis magnetic path connected in parallel to the magnets. The effectiveness of the proposed method is verified by comparisons with the FEM, and the results reveal good agreement under several conditions. Furthermore, the computation of the N-T characteristics and efficiency maps is verified, and consequently, the proposed method is deemed capable of obtaining these maps with sufficient accuracy for the initial design, and the required computation time is four orders of magnitude lower.

An Enhanced Magnetic Equivalent Circuit Model for a Magnetorheological Clutch Including Nonlinear Permeability, Flux Fringing, and Leakage Effects

Magnetorheological (MR) clutches have significant potential in electromechanical interface and are a promising technology with high commercial value in the automotive industry. A quick and precise magnetic circuit modeling method is demanded to calculate performance or optimize design of the MR clutch. Conventional magnetic circuit models present poor accuracy because they often fail to accurately include nonlinearities such as magnetic saturation, magnetic fringing, and magnetic leakage. In this regard, an enhanced magnetic equivalent circuit (EMEC) model based on lumped parameter method is proposed. This model can not only cope with clutch geometry and material properties (nonlinear permeability) but can also consider flux fringing and leakage effects. Combined with the specific structure, formulae for the calculation of fringing permeances and leakage permeances in the magnetic circuit of the MR clutch are presented. Finite-element analysis (FEA) and experimental results show that the proposed EMEC model can provide better accuracy compared with magnetic equivalent circuit (MEC) model from available literature and provide less computational effort compared with FEA. Moreover, the influence of design parameters corresponding to device geometry and material properties on the output flux density is discussed based on the proposed EMEC model. All taken together, the proposed EMEC model provides a comprehensive knowledge in optimize design and performance prediction of MR device.

Field‐circuit coupled analysis of an electromagnetic launcher sliding contact

Under the extreme working conditions of high‐speed and high‐current sliding electrical contact, if an electromagnetic launcher's rails and armature are not in good contact, transition ablation may occur, which will reduce the life of the rails. Though the transition state can be evaluated based on the muzzle voltage waveform, the conventional lumped circuit model does not take into account the strong coupling relationship of the multi‐physical fields in the launching process—in particular, there is a lack of analysis of the melt wear of the armature. To overcome this challenge, a novel approach based on the field‐circuit coupled method is proposed in this study to analyze the performance of armature‐rail contact. First, the basic principle of the co‐simulation model was introduced. The circuit model, the electromagnetic field model, the temperature field model, and the armature‐rail contact force model were then built. Compared with the conventional circuit model, the field‐circuit coupled model presented in this paper can better analyze the transient changes of the contact performance and obtain more details of multi‐physical fields. Besides, the contact performance under different interference were compared through our proposed method. The method proposed in this study comprehensively considers the influence of the velocity skin effect, armature‐rail interference assembly, and the melt wear of the armature on the performance of armature‐rail contacts. The study can provide effective theoretical guidance for conducting performance analysis and designing the armature for an electromagnetic rail launcher. © 2022 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Effect of the Series Resistance on the Current Response of a HgCdTe Avalanche Photodiode Under High-intensity Nanosecond Irradiation

We investigate the nonlinear signal current response of a Hg0.72Cd0.28Te avalanche photodiode (APD) irradiated by high-intensity, finite-duration laser pulses. At high irradiation levels and/or high gains, carrier-induced perturbations in the junction electric field and avalanche gain strongly influence the temporal behavior of the APD current. The total series resistance will play a major role here, and four values of the series resistance were used for mapping out the APD response. When striving for maximum achievable bandwidth, the internal junction capacitance and the internal series resistance set the ultimate limits for an APD. A signal analysis of these high-intensity nonlinear gain effects should therefore begin with an intrinsic APD, and proceed with adding appropriate external series resistances. A simultaneous modeling of the entire external circuit is then required. To this end, we have combined full-band Monte Carlo (MC) transport simulation in the active multiplication zone with conventional circuit modeling outside. We demonstrate how overshoot/undershoot and rapid oscillations in the signal current evolve in time as a function of the chosen external series resistances at two different high-intensity irradiation levels. Oscillations are shown to persist slightly beyond the duration of the laser pulse when operating the diode within the junction transit time-limited regime. The periodicity of the oscillations is related to the junction transit time and remains only weakly dependent on irradiation levels and external resistance values until we enter the resistance–capacitance (RC)-limited case. Here, a change occurs where oscillations are smoothed out as external series resistances are increased further.

Universal topological quantum computation with strongly correlated Majorana edge modes

Majorana-based quantum gates are not complete for performing universal topological quantum computation while Fibonacci-based gates are difficult to be realized electronically and hardly coincide with the conventional quantum circuit models. In reference Hu and Kane (2018 Phys. Rev. Lett. 120 066801), it has been shown that a strongly correlated Majorana edge mode in a chiral topological superconductor can be decomposed into a Fibonacci anyon τ and a thermal operator anyon ɛ in the tricritical Ising model. The deconfinement of τ and ɛ via the interaction between the fermion modes yields the anyon collisions and gives the braiding of either τ or ɛ. With these braidings, the complete members of a set of universal gates, the Pauli gates, the Hadamard gate and extra phase gates for one-qubit as well as controlled-NOT (CNOT) gate for two-qubits, are topologically assembled. Encoding quantum information and reading out the computation results can be carried out through electric signals. With the sparse-dense mixed encodings, we set up the quantum circuit where the CNOT gate turns out to be a probabilistic gate and design the corresponding devices with thin films of the chiral topological superconductor. As an example of the universal topological quantum computing, we show the application to Shor’s integer factorization algorithm.

Modified Small Signal Circuit of AlGaN/GaN MOS-HEMTs Using Rational Functions

Conventional lumped small signal circuit (SSC) models of AlGaN/GaN metal oxide semiconductor high electron mobility transistors (MOS-HEMTs) are derived from the low frequency portion of the experimentally measured Y-parameters. Consequently, these models cannot faithfully capture the high frequency behavior of the device. In this work, modified SSC models of AlGaN/GaN MOS-HEMTs are developed by fitting the entire broadband measured Y-parameters of the device with rational functions. These rational functions are then physically realized using additional passive circuit elements added to the conventional SSC model. The accuracy of the proposed SSC models can be improved by increasing the order of the rational functions. The proposed models are demonstrably more accurate than the conventional SSC models in estimating the higher order poles and zeroes present in the experimentally measured Y-parameters of AlGaN/GaN MOS-HEMTs.

Efficient spontaneous emission by metal-dielectric antennas; antenna Purcell factor explained

The rate of spontaneous emission from an optical emitter can be greatly enhanced using a metallic optical antenna at the penalty of efficiency. In this paper we propose a metal-dielectric antenna that eliminates the tradeoff between spontaneous emission enhancement and radiative efficiency by using nanoscopic dielectric structures at the antenna tips. This tradeoff occurs due to Ohmic loss and is further exacerbated by electron surface collisions. We find that our metal-dielectric antenna can enhance spontaneous emission by a factor 5 × 105 with efficiency = 70%, greatly exceeding the radiative efficiency of a purely metallic antenna with similar enhancement. Moreover, the metal-dielectric antenna design strategy is naturally amenable to short-distance optical communications applications. We go on to discuss the Purcell effect within the context of antenna enhancement. Metallic optical antennas are best analyzed with conventional antenna circuit models, but if the Purcell enhancement were to be employed, we provide the effective mode volume, Veff = (3/4π2)2d2λ(λ/l)5, that would be needed.

Lightning Surge Analysis of HV Transmission Line: Bias AC-Voltage Effect on Multiphase Back-Flashover

This paper discusses the back-flashover (BFO) phenomena in a high-voltage (HV) vertical double-circuit transmission line by means of numerical simulations. The single- and multiphase BFOs are analyzed considering 24 cases of AC-voltage angles and nonlinear characteristic of flashovers, taking advantage of the circuit analysis method in time domain. The models used in circuit analysis are the TEM-delay model, which can take into account the non-TEM characteristics of tower and line, and the conventional models. Prior to the BFO analysis, the characteristics of circuit models are compared and discussed with the numerical electromagnetic analysis results. In BFO analysis, it is clarified that the occurrence probability of the multiphase BFO is heavily depending on the bias AC-voltages. The relation of measured BFO phases and AC-voltages are well explained by the TEM-delay model with the valid lightning current magnitude. The conventional circuit models could have underestimated the occurrence of BFOs in HV transmission lines. The analysis and discussions shown in this paper can be utilized for advanced evaluation of lightning performance of transmission lines that considers the seriousness of lightning accidents.

Fabrication and evaluation of nanostructured microelectrodes for high-spatial resolution in retinal prostheses

To provide visual information to patients with retinal degenerative disease, retinal prosthetic devices based on multi-channel microelectrode arrays (MEAs) have shown some promising results. For high-quality information, the number of microelectrodes should be increased in the limited area of MEAs, which results in decreased dimensions of the single microelectrode and a limit of dynamic range of injection current. Previously, our research group has presented 3D microelectrodes to overcome the trade-off between high-spatial resolution and injection current range. However, the 3D microelectrode requires a complex fabrication process, including multiple steps in front-side and back-side microfabrication. In this paper, the nanostructured microelectrode with platinum-black is fabricated with a simple process, and its electrical characteristics are evaluated. The nanostructured microelectrode parameters are analyzed by a conventional three-element circuit model. The comprehensive electrical characteristics between planar 2D, 3D, and nanostructured microelectrodes with various base areas are compared by measuring electrode–electrolyte interface impedance and maximum allowable injection current limit. The experimental results show improved interface impedance in nanostructured microelectrodes compared to planar 2D and 3D microelectrodes with same base area. This implies that nanostructured microelectrodes have a large dynamic range for current stimulation, which can be more sufficient in retinal neuron stimulation. This research can be used to estimate the theoretical limit of injection current for high-resolution MEAs.

Time-domain modeling of nonlinear circuits using deep recurrent neural network technique

This paper introduces Deep Recurrent Neural Network (DRNN) structure for time-domain modeling of nonlinear circuits. DRNN can be directly trained by sampled input-output waveforms of the original nonlinear circuit without knowing the internal details of the circuit. A training algorithm based on Real-Time Recurrent Learning (RTRL) is developed to train the proposed DRNN. After the training phase, DRNN provides accurate and fast macromodel of the nonlinear circuit. Our experimental results show that DRNN extends the ability of conventional neural-based models to express the dynamic behavior of a nonlinear circuit, and also significantly enhances the accuracy of the conventional neural circuit modeling. Moreover, DRNN is considerately faster than the existing models in simulation tools. The validity and advantages of the proposed deep learning-based method are verified by time-domain modeling of three nonlinear devices including 5-stage CMOS receiver, commercial TI’s LM324 power amplifier, and TI’s SN74AHCT540 device.

Conventional Hydraulic Circuits in an Analysis of Environmental Issues

The paper addresses the problems of conventional circuit modeling in an analysis of anthropogenic pollution of nature. A joint use of two types of models is proposed: 1) a model of conventional hydraulic circuits and 2) a model of extreme intermediate states developed by Melentiev Energy Systems Institute. The first model is used to calculate the distribution of pollutants in the atmosphere and their precipitation. The second model is intended for an analysis of the formation of pollutants and their transformations in branches as a result of chemical reactions and phase transitions. The analysis is based on the propositions of classical equilibrium thermodynamics. The applicability of the thermodynamic equilibrium and extremality principles and one-dimensional circuit models in the study of both reversible and irreversible processes are substantiated. Specific problems are analyzed. These are the determination of the yield of harmful substances in fuel combustion and processing, the distribution of pollutants in the atmosphere of large regions, the impact of hydro and wind power plants on the formation of harmful solutions in the air. The possibility of using a conventional graph (a thermodynamic tree) proposed by A.N. Gorban to analyze fuel technologies is demonstrated. The statement of the problem related to the assessment of the environmental compatibility of integrated energy systems is presented. The admissibility of the representation of the optimal distribution of flows in the integrated system as a sum of optimal distributions in its subsystems that differ from one another in physical-technical and economic nature is explained.

New Theoretical Model of Nerve Conduction in Unmyelinated Nerves

Nerve conduction in unmyelinated fibers has long been described based on the equivalent circuit model and cable theory. However, without the change in ionic concentration gradient across the membrane, there would be no generation or propagation of the action potential. Based on this concept, we employ a new conductive model focusing on the distribution of voltage-gated sodium ion channels and Coulomb force between electrolytes. Based on this new model, the propagation of the nerve conduction was suggested to take place far before the generation of action potential at each channel. We theoretically showed that propagation of action potential, which is enabled by the increasing Coulomb force produced by inflowing sodium ions, from one sodium ion channel to the next sodium channel would be inversely proportionate to the density of sodium channels on the axon membrane. Because the longitudinal number of sodium ion channel would be proportionate to the square root of channel density, the conduction velocity of unmyelinated nerves is theoretically shown to be proportionate to the square root of channel density. Also, from a viewpoint of equilibrium state of channel importation and degeneration, channel density was suggested to be proportionate to axonal diameter. Based on these simple basis, conduction velocity in unmyelinated nerves was theoretically shown to be proportionate to the square root of axonal diameter. This new model would also enable us to acquire more accurate and understandable vision on the phenomena in unmyelinated nerves in addition to the conventional electric circuit model and cable theory.

Lagrangian‐based equivalent circuit of basic electric‐field coupling wireless power transfer system

Electric‐field coupling wireless power transfer has been commonly analyzed using the circuit model. However, the circuit behavior of this model is not necessarily apparent because their resonant modes can be far complicated than the basic LC oscillation. This issue is addressed in this paper by proposing a novel equivalent circuit for a basic wireless power transfer system. This equivalent circuit has a simpler topology than the conventional circuit model. Furthermore, the equivalent circuit allows intuitive understanding of three types of the resonant modes. Along with theoretical derivation of the proposed equivalent circuit, this paper also presents simulation results, which verified the appropriateness of the equivalent circuit. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Perspective on resonances of metamaterials.

Electromagnetic resonance as the most important characteristic of metamaterials enables lots of exotic phenomena, such as invisible, negative refraction, man-made magnetism, etc. Conventional LC-resonance circuit model as the most authoritative and classic model is good at explaining and predicting the fundamental resonance wavelength of a metamaterial, while feels hard for high-order resonances, especially for resonance intensity (strength of resonance, determining on the performance and efficiency of metamaterial-based devices). In present work, via an easy-to-understand mass-spring model, we present a different and comprehensive insight for the resonance mechanism of metamaterials, through which both the resonance wavelengths (including the fundamental and high-order resonance wavelengths) and resonance intensities of metamaterials can be better understood. This developed theory has been well verified by different-material and different-structure resonators. This perspective will provide a broader space for exploring novel optical devices based on metamaterials (or metasurfaces).

Behavioral Model of Patterned Vertical Alignment Pixel in Active-Matrix Liquid Crystal Displays

This paper proposes a more accurate behavioral circuit model to predict transient responses of an active-matrix liquid crystal display (AMLCD) with a patterned vertical alignment (PVA) mode. In the case of the PVA mode, we observed that simulation errors increase when the conventional circuit model is directly applied to overdriven static and dynamic data transitions. To overcome this issue, we investigate the actual behavior of the liquid crystal (LC) molecules in the PVA AMLCD pixel using a high-speed camera attached to a microscope. We discovered that the behavior of the LC molecules is significantly dependent on their proximity to the edges of transparent electrodes. Based on this investigation, we propose a first-order circuit model that has two LC groups with two different response characteristics. The proposed model is embedded in a circuit simulator using an analog hardware description language. Simulation results show that the transient optical responses are considerably more accurate than the conventional responses for any data transitions, including overdriven transitions.

An improved circuit model for polymer solar cells

ABSTRACTAuthenticity of conventional circuit model, to interpret the characteristics of polymer solar cells (PSCs) is examined. Conventional circuit model is found to be quite limited, and various assumptions used there are not valid for PSCs. By understanding the nature of photovoltaic characteristics, through detailed investigations, we developed an improved circuit model, which explains correctly the behavior of PSCs under different environmental conditions. Investigations are carried out on the solar cells, made of the blend of regioregular poly(3‐hexylethiophene) (P3HT) and phenyl [6,6] C61 butyric acid methyl ester (PCBM). The model is developed by treating both the dark and illuminated characteristics separately, even the characteristics were dealt with separately in reverse and forward biases. The formulated equivalent circuit model helps us in explaining many other important features, observed in the characteristics of PSCs. Copyright © 2013 John Wiley & Sons, Ltd.

Influence of Parasitic Capacitance on Output Voltage for Series-Connected Thin-Film Piezoelectric Devices

Series-connected thin film piezoelectric elements can generate large output voltages. The output voltage ideally is proportional to the number of connections. However, parasitic capacitances formed by the insulation layers and derived from peripheral circuitry degrade the output voltage. Conventional circuit models are not suitable for predicting the influence of the parasitic capacitance. Therefore we proposed the simplest model of piezoelectric elements to perform simulation program with integrated circuit emphasis (SPICE) circuit simulations). The effects of the parasitic capacitances on the thin-film Pb(Zr, Ti)O3, (PZT) elements connected in series on a SiO2 insulator are demonstrated. The results reveal the negative effect on the output voltage caused by the parasitic capacitances of the insulation layers. The design guidelines for the devices using series-connected piezoelectric elements are explained.

Spike suppression in a local cortical circuit induced by transcranial magnetic stimulation

Transcranial magnetic stimulation (TMS) noninvasively interferes with human cortical function, and is widely used as an effective technique for probing causal links between neural activity and cognitive function. However, the physiological mechanisms underlying TMS-induced effects on neural activity remain unclear. We examined the mechanism by which TMS disrupts neural activity in a local circuit in early visual cortex using a computational model consisting of conductance-based spiking neurons with excitatory and inhibitory synaptic connections. We found that single-pulse TMS suppressed spiking activity in a local circuit model, disrupting the population response. Spike suppression was observed when TMS was applied to the local circuit within a limited time window after the local circuit received sensory afferent input, as observed in experiments investigating suppression of visual perception with TMS targeting early visual cortex. Quantitative analyses revealed that the magnitude of suppression was significantly larger for synaptically-connected neurons than for isolated individual neurons, suggesting that intracortical inhibitory synaptic coupling also plays an important role in TMS-induced suppression. A conventional local circuit model of early visual cortex explained only the early period of visual suppression observed in experiments. However, models either involving strong recurrent excitatory synaptic connections or sustained excitatory input were able to reproduce the late period of visual suppression. These results suggest that TMS targeting early visual cortex disrupts functionally distinct neural signals, possibly corresponding to feedforward and recurrent information processing, by imposing inhibitory effects through intracortical inhibitory synaptic connections.