bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship marketing: schools of thought and future research directions
Authors: Palmer Roger , Lindgreen Adam , Vanhamme Joëlle 
Published: June 2005

PurposeThe purpose of this article is to challenge the applicability of the traditional micro‐economic framework for analysing marketing situations and actions in the contemporary marketing environment. To assess the validity and value of relationship marketing as an alternative paradigm. To identify fruitful directions for further research.Design/methodology/approachThe literature of relationships and relationship marketing was systematically reviewed and thoroughly analysed, and a conceptual framework built from the findings.FindingsThree key schools of thought are identified, examined and discussed, and their main components explained and examined. Various perspectives on exchange relationships are discussed. Two specific tools for implementation of relationship marketing are evaluated. With a clear conceptual frame of reference thus established, the second part proposes a number of fruitful directions for further research. These include a bibliometric study to assess whether or not a consistent theory of relationship marketing exists, and a rigorous identification of contextual factors determining different marketing styles.Research limitations/implicationsThe second part of the paper explicitly discusses research directions to take the new paradigm forward, in theory and in practice.Practical implicationsThe combination of a more rigorous conceptual framework and a clear research agenda holds the promise of significant progress in the practical implementation of a young sub‐discipline.Originality/valueThe paper presents a distinctively wide‐ranging and thorough overview of the subject of value to both academic researchers and marketing practitioners.
Symmetrization of asymmetrical three‐phase load supplied from non‐ideal periodic non‐sinusoidal voltage source using simplified structure of the compensator
Authors: Dębowski Krzysztof , Pasko Marian 
Published: June 2005

PurposeThe problems presented in the paper concern a three‐phase four‐wire system with periodical non‐sinusoidal voltage sources with inner impedances and asymmetrical linear three‐phase loads. Generally, the line currents of the system are asymmetrical. The purpose of the paper is to improve the working conditions of the system by means of symmetrization.Design/methodology/approachA method of symmetrization of these systems has been proposed. In this paper, the symmetrization problem has been solved by using the symmetrical components theory and compensation of reactive power for each of voltage harmonics under consideration.FindingsAfter symmetrization currents become symmetrical and their RMS values and active power on source impedances become lower. The realization of symmetrization makes possible: reduction of RMS values of source currents, an assurance of equal loads for individual phases of the system supplied from sources with inner impedances, after symmetrization the voltage source generates and load consumes greater useful active power.Originality/valueThe simplified structure of the compensator has been proposed in the paper. The symmetrization has been presented with reference to new structure of the compensator.
Non‐negative matrix factorization and its application in blind sparse source separation with less sensors than sources
Authors: Li Yuanqing , Cichocki Andrzej 
Published: June 2005

PurposeProposes a non‐negative matrix factorization method.Design/methodology approachPresents an algorithm for finding a suboptimal basis matrix. This is controlled by data cluster centers which can guarantee that the coefficient is very sparse. This leads to the proposition of an application of non‐matrix factorization for blind sparse source separation with less sensors than sources.FindingsTwo simulation examples reveal the validity and performance of the algorithm in this paper.Originality/valueUsing the approach in this paper, the sparse sources can be recovered even if the sources are overlapped to some degree.
Transient analysis of nonlinear dynamic circuits using a numerical‐integration method
Authors: Tadeusiewicz Michał , Hałgas Stanisław 
Published: June 2005

PurposeDeveloping an efficient second‐order integration method of transient analysis of nonlinear dynamic circuits which overcomes the main drawback of the trapezoidal rule.Design/methodology/approachDynamic circuits including transistors and operational amplifiers are considered. A new family of two‐step, second‐order numerical integration algorithms has been developed using a polynomial approximation.FindingsThe algorithms have been worked out which are implicit, A‐stable and they depend on a parameter which is allowed to be changed during the computation process according to a proposed strategy. Also the variable step‐size formula has been derived enabling us to eliminate a restarting procedure. The method has been implemented and tested using several representative circuits. It has been compared, both theoretically and via numerical examples, with the alternative well known algorithms: the trapezoidal rule and the backward differentiation formula of order two.Research limitation/implicationsThe algorithms developed in the paper are two‐step and second‐order, consequently the step size cannot be too large and the algorithms are not L‐stable.Originality/valueA new family of two‐step implicit integration algorithms is developed. It can be useful for the analysis and design of electronic circuits.
Curl‐conform source fields in finite element formulations
Authors: Dular Patrick 
Published: June 2005

PurposeThis paper proposes an automatic procedure to characterize discrete source fields.Design/methodology/approachA technique is developed to characterize curl‐conform fields to be used as source fields or non‐local basis functions in finite element formulations. A reduced characterization of such fields using curl‐conform finite elements is defined. An automatic construction of these curl‐conform spaces is proposed.FindingsA reduced characterization of such fields is shown to be convenient for the coupling with complementary reaction fields and for simply and explicitly defining non‐local quantities, such as currents in h‐conform magnetodynamic formulations. The reduced form rests on the choice of supports for the fields limited to reduced cut spaces associated with cuts making the definition domain simply connected.Originality/valueDevelops a procedure to simplify the construction of curl‐conform source fields.
Analysis of iron loss under distorted elliptical rotating flux of SPM motor
Authors: Takahashi N. , Fukum A. , Miyagi D. 
Published: June 2005

PurposeIn this paper, a new method for estimating iron loss under a distorted elliptical rotating flux is proposed.Design/methodology/approachIn order to precisely analyze the iron loss of rotating machines, the iron loss under distorted rotating flux should be taken into account. However, reports of precise analysis considering measured iron loss data under rotating flux are few.FindingsThe iron loss of surface permanent magnet (SPM) motor model proposed by the investigation committee of IEE of Japan is estimated using the proposed method. The experimental examination is carried out by measuring the iron loss of the motor using a torque meter.Originality/valueExamines an estimation method of iron loss of motors.
Robust and efficient FETI domain decomposition algorithms for edge element approximations
Authors: Toselli Andrea , Vasseur Xavier 
Published: June 2005

PurposeA family of preconditioned dual‐primal FETI iterative algorithms for the solution of algebraic systems arising from edge element approximations in two dimensions is presented.Design/methodology/approachThe primal constraints, which determine the size of the coarse problem to be solved at each iteration step, are here suitable averages over subdomain edges. The condition number of the corresponding methods is independent of the number of subdomains and possibly large jumps of the coefficients.FindingsFor h finite elements, it grows only polylogarithmically with the number of unknowns associated with individual substructures, while for hp approximations on geometrically refined meshes, it is independent of arbitrarily large aspect ratios.Originality/valueProposes an algorithm with a rate of convergence that is independent of possibly large jumps of the coefficients and mesh aspect ratios.
Comparison of semi‐analytical and FEM solutions in a certain magnetic fluid dynamics problem
Authors: Ziolkowski Marek , Brauer Hartmut , Kuilekov Milko 
Published: June 2005

PurposeTo provide a new semi‐analytical procedure which is much faster than FEM and for this reason can be applied in a reconstruction of an interface between two conducting fluids (magnetic fluid dynamics problem) by means of magnetic field tomography.Design/methodology/approachThree approaches are compared: a simple analytical solution (AS1), a modified semi‐analytical solution (AS2), and the finite element method solution. The modified semi‐analytical approach takes into account an information about azimuthal spatial harmonics received from the Fourier analysis of magnetic flux density distributions calculated by FEM. AS1 and AS2 have been compared for different modes of the interface using FEM solution as a reference.FindingsIt is shown that for small perturbations the AS2 in every case provides smaller errors than AS1 although for some modes (14,24) the quality of the solution is still not satisfactory.Originality/valueThis paper describes a new technique for the analysis of electromagnetic field which can be also applied in other problems.
Qualification of the inverse problem of defect reconstruction using optimized mesh database
Authors: Gyimóthy Szabolcs , Pávó József 
Published: June 2005

PurposeTo propose a novel method for defect reconstruction in electromagnetic non‐destructive testing (NDT).Design/methodology/approachThe inversion method is based on an optimized database that contains the measured signals for some predefined defect prototypes. The database is supported by an anisotropic simplex mesh, which has been generated adaptively in the abstract n‐dimensional space, spanned by the model parameters of the defect type. The actual reconstruction reduces to a mesh search and interpolation. The described theory is demonstrated in the paper by a solved NDT test problem.FindingsWe have realized that in addition to sole defect reconstruction, the database provides meta‐information about the quality of the inversion, the suitability of the chosen defect model parameters, as well as the capabilities of the testing experiment.Research limitations/implicationsDefect models having several parameters require a sophisticated mesh generation algorithm, which works in higher dimensions.Originality/valueIn the authors' opinion the mesh database approach offers a totally new point of view of a given inverse problem, and may help in the better understanding of its nature.
An integral approach based on dual discretization and method of moment for the solution of static electric field
Authors: Canova A. , Gruosso G. , Repetto M. 
Published: June 2005

PurposeThe scope of the work is to provide an hybrid numerical technique for the solution of electric field.Design/methodology/approachIn this paper an integral approach for the solution of static electric field based on a dual discretization (DD) and on a surface method of moment (MoM) is presented. The proposed technique is applied to the solution of 3D electric field problems where different perfectly conducting bodies are placed in a homogeneous and isotropic medium. The approach is also extended to the analysis of static current field. In the presented formulation MoM is applied on a surface domain which is discretized according to a baricentrical dual scheme.FindingsThe procedure has been applied to several practical cases and it represents an efficient tool for the evaluation of lumped circuit parameters as capacitances of 3D conducting bodies and ground resistance of grounding systems.Research limitations/implicationsThe formulation presented in the paper is limited to the calculus of electric field in homogeneous media. For future development the authors are working in order to include non‐homogeneous media.Practical implicationsThe proposed approach aids the designer of electrical systems as large scale grounding systems or integrated circuit connections in the calculations of lumped electrical parameters.Originality/valueThe originality of the paper lies in the coupling of MoM with finite formulation and DD.
Parallelized computation of compressed BEM matrices on multiprocessor computer clusters
Authors: Buchau André , Hafla Wolfgang , Groh Friedemann , Rucker Wolfgang M. 
Published: June 2005

PurposeVarious parallelization strategies are investigated to mainly reduce the computational costs in the context of boundary element methods and a compressed system matrix.Design/methodology/approachElectrostatic field problems are solved numerically by an indirect boundary element method. The fully dense system matrix is compressed by an application of the fast multipole method. Various parallelization techniques such as vectorization, multiple threads, and multiple processes are applied to reduce the computational costs.FindingsIt is shown that in total a good speedup is achieved by a parallelization approach which is relatively easy to implement. Furthermore, a detailed discussion on the influence of problem oriented meshes to the different parts of the method is presented. On the one hand the application of problem oriented meshes leads to relatively small linear systems of equations along with a high accuracy of the solution, but on the other hand the efficiency of parallelization itself is diminished.Research limitations/implicationsThe presented parallelization approach has been tested on a small PC cluster only. Additionally, the main focus has been laid on a reduction of computing time.Practical implicationsTypical properties of general static field problems are comprised in the investigated numerical example. Hence, the results and conclusions are rather general.Originality/valueImplementation details of a parallelization of existing fast and efficient boundary element method solvers are discussed. The presented approach is relatively easy to implement and takes special properties of fast methods in combination with parallelization into account.
Electric machine operational modeling utilizing coupled electromagnetic and electric drives simulations
Authors: Mohammed O.A. , Liu Z. , Liu S. , Abed N.Y. 
Published: June 2005

PurposeThe purpose of this research is to develop new techniques for component physical modeling for the dynamic simulation of integrated power systems.Design/methodology/approachA FE‐based phase variable model is proposed so as to achieve fast and accurate simulation. Such a model is established based on the nonlinear transient FE analysis, in order to take into consideration the harmonic effects due to the nonlinear magnetization property, magnetic circuit geometry as well as other design variations.FindingsIn the FE‐based phase variable model, the inductances are described as functions of the phase angle and the magnitude of winding currents, the rotor position and other operational parameters. They are obtained from the transient FE solutions, stored in tables, and retrieved during the simulation. The FE‐based phase variable model is implemented in Simulink in two ways. The first is the equation‐based block and the second is the circuit component‐based block. The FE‐based phase variable models of various electrical components in the power system were studied. This includes various types of rotating machines and transformers. Examination and application examples show the correctness and effectiveness of the proposed operational modeling procedures.Originality/valueThe developed FE‐based physical phase variable model is as accurate as the full FE model with much faster simulation speed. It will benefit the dynamic simulation of integrated power system. This combination of physical modeling and integrated dynamic simulation is original and represents an added value to the state‐of‐the‐art in this field.
Band gaps in photonic crystals with dispersion
Authors: Szabó Zsolt , Kádár György , Volk János 
Published: June 2005

PurposeThe paper presents the band gap computation in one‐ and two‐dimensional photonic crystals built up from porous silicon. The frequency dispersion of the dielectric materials is taken into account.Design/methodology/approachThe behavior of the light in a photonic crystal can be well described by the Maxwell equations. The finite difference time domain (FDTD) method is applied to determine the band structure. The frequency dependence of the dielectric constant is taken into account by a sum of second‐order Lorenz poles. The material parameters are determined applying a conjugate gradient‐based minimization procedure. Passing a light pulse of Gaussian distribution through the photonic crystal and analyzing the transmitted wave can explore the photonic bands.FindingsThe realized simulations and visualizations can lead to a much better understanding of the behavior of electromagnetic waves in dispersive photonic crystals, and can make possible to set up experimental conditions properly. The obtained results show again that silicon and porous silicon can be used for the fabrication of photonic crystals.Research limitations/implicationsDue to the high computational requirements of the three‐dimensional case we plan to work out a parallel version of the presented FDTD algorithm.Originality/valueThis paper presents a simple way to take into account the frequency dispersion in the simulation of photonic crystals with the FDTD method.
Identification and simulation of a circuit‐based model of magnetic hysteresis
Authors: Gruosso G. , Repetto M. 
Published: June 2005

PurposeThe scope of the work is to provide an identification procedure for an hysteresis model based on nonlinear circuit cells.Design/methodology/approachAn identification procedure for an hysteresis model based on nonlinear circuit cells is presented. The response of elementary cell is equal to a generalized play operator. The procedure allows the identification of the limit symmetric hysteresis loop and of minor loops. The identification procedure is based on the relationship between the circuit parameters and the discretization of the first derivative of the BH curve by means of a staircase function.FindingsThe model obtained is employed for the simulation of soft magnetic composite material cores under different supply voltage waveforms. The proposed identification procedure is able to define an accurate model of an hysteretic material with a low number of elemental network cells. The identification algorithm is simple and makes use of the limit hysteresis cycle only. Symmetric minor loops are used to tune “soft” operators for the correct reconstruction of cycles which do not reach saturation.Research limitations/implicationsThe model is limited to scalar and static hysteresis model.Practical implicationsThe model obtained can be used in network simulator like SPICE in order to model circuits in which magnetic devices are involved.Originality/valueThe circuit hysteresis model has been presented in literature, while its identification is newly proposed by the authors.
An analysis of magnetic shielding against DC power lines based on homogenization
Authors: Waki H. , Igarashi H. , Honma T. 
Published: June 2005

PurposeTo analyze effectively magnetic shielding effects by shields with fine structure.Design/methodology/approachSimplification of the fine structure makes it possible to analyze them efficiently. The authors have introduced a homogenization method to estimate effective permeability of magnetic composite structure for the static field. The homogenization method is applied to the analysis of magnetic shields composed of steel plates and steel rods against DC power lines to test its feasibility.FindingsThe properties of the magnetic shielding are analyzed by using the homogenization method. The errors of the magnetic fields increase in case of very few layers.Originality/valueThe simplification of the magnetic shields with fine structure by using the homogenization method makes it possible to analyze efficiently magnetic shielding effects, although the accuracy becomes worse in case of very few layers.
A FEM‐BEM approach using level‐sets in electrical capacitance tomography
Authors: Kortschak Bernhard , Brandstätter Bernhard 
Published: June 2005

PurposeFor the spatial reconstruction of a two phase flow, as it might occur in a pipe, the main problem has always been the blurring of the resulting images.Design/methodology/approachIn this paper, we present a method where blurring is implicitly avoided by the use of level sets. The level set method describes the iteratively evolving interface between different materials. The underlying field problem is solved with the boundary element method formulated in the region, where the degrees of freedom are present and the finite element method in all other regions.FindingsFinally reconstruction results of an electrical capacitance tomography sensor are presented to show the validity of the method.Originality/valuePresents a method where blurring is avoided by the use of level sets.
Statistical robust design using the unscented transformation
Authors: Steiner Gerald , Watzenig Daniel , Magele Christian , Baumgartner Ulrike 
Published: June 2005

PurposeTo establish a statistical formulation of robust design optimization and to develop a fast optimization algorithm for the solution of the statistical design problem.Design/methodology/approachExisting formulations and methods for statistical robust design are reviewed and compared. A consistent problem formulation in terms of statistical parameters of the involved variables is introduced. A novel algorithm for statistical optimization is developed. It is based on the unscented transformation, a fast method for the propagation of random variables through nonlinear functions. The prediction performance of the unscented transformation is demonstrated and compared with other methods by means of an analytical test function. The validity of the proposed approach is shown through the design of the superconducting magnetic energy storage device of the TEAM workshop problem 22.FindingsProvides a consistent formulation of statistical robust design optimization and an efficient and accurate method for the solution of practical problems.Originality/valueThe proposed approach can be applied to all kinds of design problems and allows to account for the inevitable effects of tolerances and parameter variations occuring in practical realizations of designed devices.