Modified nodal analysis
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Room acoustics modelling in the time-domain with the nodal discontinuous Galerkin method Open
To solve the linear acoustic equations for room acoustic purposes, the performance of the time-domain nodal discontinuous Galerkin (DG) method is evaluated. A nodal DG method is used for the evaluation of the spatial derivatives, and for t…
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On the Properties of the Power Systems Nodal Admittance Matrix Open
This letter provides conditions determining the rank of the nodal admittance matrix, and arbitrary block partitions of it, for connected AC power networks with complex admittances. Furthermore, some implications of these properties concern…
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Comparison of Pressure-Driven Formulations for WDN Simulation Open
This paper presents the comparison of five pressure-driven formulations in the context of water distribution network (WDN) modelling. These formulations, which relate nodal outflow q to users to demands d and nodal pressure heads h, were i…
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On the Properties of the Compound Nodal Admittance Matrix of Polyphase Power Systems Open
Most techniques for power system analysis model the grid by exact electrical circuits. For instance, in power flow study, state estimation, and voltage stability assessment, the use of admittance parameters (i.e., the nodal admittance matr…
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An Analytical Formulation for Mapping the Spatial Distribution of Nodal Inertia in Power Systems Open
Mapping the spatial distribution of nodal inertia is crucial for helping system operators identify locational frequency stability issues in the power system operation planning process. Currently, index-based methods cannot retrieve the nod…
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Lcapy: symbolic linear circuit analysis with Python Open
Lcapy is an open-source Python package for solving linear circuits symbolically. It uses a superposition of DC analysis, AC (phasor) analysis, transient (Laplace) analysis, and noise analysis. Expressions are evaluated using the computer a…
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<b>The Inverse Nodal problem for the fractional diffusion equation Open
"In this paper, on a general finite interval, the inverse problem of recovering the potential function for a fractional diffusion equation with new spectral parameter, called the nodal point, is given. Furthermore, using Mittag Leffler fun…
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Verification of a two-step code system MCS/RAST-F to fast reactor core analysis Open
RAST-F is a new full-core analysis code based on the two-step approach that couples a multi-group cross-section generation Monte-Carlo code MCS and a multi-group nodal diffusion solver. To demonstrate the feasibility of using MCS/RAST-F fo…
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A Parallel Probabilistic Load Flow Method Considering Nodal Correlations Open
With the introduction of more and more random factors in power systems, probabilistic load flow (PLF) has become one of the most important tasks for power system planning and operation. Cumulants-based PLF is an effective algorithm to calc…
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Accelerated Spatially Resolved Electrical Simulation of Photovoltaic Devices Using Photovoltaic-Oriented Nodal Analysis Open
This paper presents photovoltaic-oriented nodal analysis (PVONA), a general and flexible tool for efficient spatially resolved simulations for photovoltaic (PV) cells and modules. This approach overcomes the major problem of the convention…
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Numerical investigation of the inverse nodal problem by Chebisyhev interpolation method Open
In this study, we deal with the inverse nodal problem for Sturm-Liouville equation with eigenparameter-dependent and jump conditions. Firstly, we obtain reconstruction formulas for potential function, q, under a condition and boundary data…
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Anisotropic nonlinear optical response of nodal-loop materials Open
Nodal line semimetals have lately aroused much experimental and theoretical\ninterest, with their gap closing along unconventional trajectories in the 3D\nBrillouin zone. These trajectories or nodal lines can close into loops and\ntrace ou…
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Calculating Nodal Voltages Using the Admittance Matrix Spectrum of an Electrical Network Open
Calculating nodal voltages and branch current flows in a meshed network is fundamental to electrical engineering. This work demonstrates how such calculations can be performed using the eigenvalues and eigenvectors of the Laplacian matrix …
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Time-dependent neutronics model of nodal neutronics program Ants Open
Ants is a nodal neutronics program developed at VTT since 2017. Ants solution method for the nodal diffusion equation is based on the function expansion nodal method (FENM) and analytic function expansion nodal (AFEN) method. Ants supports…
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Inverse nodal problem for p_Laplacian diffusion equation with polynomially dependent spectral parameter Open
In this study, solution of inverse nodal problem for one-dimensional p-Laplacian diffusion equation is extended to the case that boundary condition depends on polynomial eigen parameter. To find the spectral datas as eigen values and nodal…
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On inverse spectral problem and generalized Sturm nodal theorem for nonlinear boundary value problems Open
In the present paper, we are concerned with the Sturm-Liouville operator ℒ[] := - ′′ + () subject to the separated boundary conditions.We suppose that ∈ 2 (0, ) and study a so-called inverse optimization spectral problem: given a potential…
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Topological algorithm for forming nodal stresses of complex networks energy systems Open
The paper presents a new topological algorithm for the formation of nodal stresses of complex networks of power systems. The first step of the described algorithm is the search and determination of the values of all possible and specific t…
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Analytical Computation of Power Grids’ Sensitivity Coefficients with Voltage-Dependent Injections Open
With the increasing need of real-time regulation in power systems, grid-aware-control-frameworks are relying more often on sensitivity coefficients (SCs) to formulate and efficiently solve optimal control problems. As known, SCs are the de…
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A variational nodal formulation for multi-dimensional unstructured neutron diffusion problems Open
A variational nodal method (VNM) with unstructured-mesh is presented for solving steady-state and dynamic neutron diffusion equations. Orthogonal polynomials are employed for spatial discretization, and the stiffness confinement method (SC…
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MONA—A magnetic oriented nodal analysis for electric circuits Open
The modified nodal analysis (MNA) is probably the most widely used formulation for the modeling and simulation of electric circuits. Its conventional form uses electric node potentials and currents across inductors and voltage sources as u…
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An analytical nodal method for energy multi-group discrete ordinates transport calculations in two-dimensional rectangular geometry Open
A spectral nodal method for energy multi-group X, Y-geometry, discrete ordinates (SN) problems in non-multiplying medium is developed. This analytical coarse-mesh method is referred to as the multi-group spectral Green's function - constan…
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Characteristic singular behaviors of nodal-line materials emerging in orbital magnetic susceptibility and Hall conductivity Open
The bulk properties of nodal line materials have been an important research\ntopic in recent years. In this paper, we study the orbital magnetic\nsusceptibility and the Hall conductivity of nodal line materials using the\nformalism with th…
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On the Lipschitz stability of inverse nodal problem for Dirac system Open
Inverse nodal problem on Dirac operator is determination problem of the parameters in the boundary conditions, number m and potential function V by using a set of nodal points of a component of two component vector eigenfunctions as the gi…
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The modified nodal analysis method applied to the modeling of the thermal circuit of an asynchronous machine Open
The complexity of electrical circuits or of equivalent thermal circuits that were considered to be analyzed and solved requires taking into account the method that is used for their solving. Choosing the method of solving determines the am…
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Hexagonal Zr3X (X = Al, Ga, In) Metals: High Dynamic Stability, Nodal Loop, and Perfect Nodal Surface States Open
In recent years, topological semimetals/metals, including nodal point, nodal line, and nodal surface semimetals/metals, have been studied extensively because of their potential applications in spintronics and quantum computers. In this stu…
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Classical Lagrange Interpolation Based on General Nodal Systems at Perturbed Roots of Unity Open
The aim of this paper is to study the Lagrange interpolation on the unit circle taking only into account the separation properties of the nodal points. The novelty of this paper is that we do not consider nodal systems connected with ortho…
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Inverse Nodal Problem for a Conformable Fractional Diffusion Operator With Parameter-Dependent Nonlocal Boundary Condition Open
In this paper, we consider the inverse nodal problem for the conformable fractional diffusion operator with parameter-dependent Bitsadze–Samarskii type nonlocal boundary condition. We obtain the asymptotics for the eigenvalues, the eigenfu…
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Port Parameter Extraction-Based Self-Consistent Coupled EM-Circuit FEM Solvers Open
Self consistent solution to electromagnetic (EM)-circuit systems is of\nsignificant interest for a number of applications. This has resulted in\nexhaustive research on means to couple them. In time domain, this typically\ninvolves a tight …
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Semi-Lagrangian nodal discontinuous Galerkin method for the BGK Model Open
In this paper, we propose an efficient, high order accurate and asymptotic-preserving (AP) semi-Lagrangian (SL) method for the BGK model with constant or spatially dependent Knudsen number. The spatial discretization is performed by a mass…
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The partial inverse nodal problem for differential pencils on a finite interval Open
In this paper, the partial inverse nodal problem for differential pencils with real-valued coefficients on a finite interval \([0,1]\) was studied. The authors showed that the coefficients \((q_{0}(x),q_{1}(x),h,H_0)\) of the differential …