bluuebunny/crossref_metadata_2025 huggingface dataset:
Design procedure for a polarization- transformation filter with a genetic Algorithm
Authors: Kusunoki Atsushi , Tanaka Mitsuru
Published: December 2018

This paper presents a design procedure for a polarization-transformation transmission filter, which is composed of a chiral multilayer. The design procedure proposed is divided into two stages. An ordinary filter and a polarization-transformation filter for the transmitted wave are designed with a non-chiral multilayer and a chiral multilayer at the first and the second stages, respectively. According to the specifications of the filters, two objective functions are defined with the transmitted and reflected powers. Applying a genetic algorithm to the maximization of the objective functions, one can obtain the optimal material parameters and thicknesses of the chiral multilayer. Numerical results are given to confirm the validity of the two-stage design procedure. It is seen from the numerical results that the proposed procedure is very effective in the optimal design of a polarization-transformation band-pass filter for the transmitted wave.
Experimental investigation of linear and rotatory HTSC bearings for industrial applications
Authors: Siems Sven Olav , Canders Wolf-Rüdiger
Published: December 2018

This paper presents an innovative bearing design for linear and rotatory superconducting magnetic bearings. In order to evaluate the bearings characteristics, two test benches have been set up and several tests for a temperature range from 40 K to 80 K have been performed. A description of the test facilities and the results are presented. Further the realization of the necessary activation process for SMB is discussed and a solution is given, which makes the use of SMB possible for applications that don't allow any displacement of the suspended part of the machinery.
End effect modelling in eddy current tube testing with bobbin coils
Authors: Theodoulidis Theodoros
Published: December 2018

A semi-analytical method for modelling electromagnetic fields is applied to eddy current nondestructive evaluation (NDE) to simulate the end effect in tube testing with bobbin coils. The boundary value problem is formulated in terms of the magnetic vector potential and is solved using orthogonal eigenfunctions, the eigenvalues of which are computed as roots of a transcendent complex equation. Closed-form expressions are derived for the impedance change of the coil and the induced eddy currents. The results are in excellent agreement with those obtained by a 2D-finite element package.
Brushless PM linear actuator for high acceleration textile winding applications
Authors: Jakeman Nigel , Bullough William , Bingham Chris , Mellor Phil
Published: December 2018

The paper describes the specification, modelling, magnetic design, thermal characteristics and control of a novel, high acceleration (up to 82g) brushless permanent magnet linear actuator with Halbach array, for textile package winding applications. Development, optimisation and the construction of a prototype machine is discussed in detail. Experimental results demonstrate the realisation of the actuator and induced performance advantages afforded by the closed loop position control system.
Development of a device for measurement of hysteresis magnetization curves of charpy impact test pieces
Authors: Ebine Noriya , Suzuki Masahide , Ara Katsuyuki , Kikuchi Hiroaki , Abe Takashi , Kamada Yasuhiro , Takahashi Seiki , Fujiwara Koji
Published: December 2018

A device for nondestructive measurement of dc hysteresis magnetization characteristics of Charpy impact test pieces was developed for investigating the correlation between changes of ductile-brittle transition temperature and magnetic hysteresis characteristic of nuclear reactor pressure vessel steel due to neutron irradiation. Operation tests verified satisfying performances of its designed functions.
Geometric design of pole arcs considering electric parameters in switched reluctance motor
Authors: Choi Jae-hak , Lee Ju , Kim Youn-hyun
Published: December 2018

This paper presents a design scheme to minimize torque ripple in 6/4 Switched Reluctance Motor (SRM) using transient Finite Element Analysis (FEA) in which the magnetic field is combined with a driving circuit. Pole arcs and switching angles are major design factors. If these design factors are considered independently, the enhancement of SRM performance is restricted. Therefore this paper proposes not only optimal combination of stator pole arc and rotor pole arc but also the turn-on and turn-off angles as a function of pole arcs. Especially, turn-on and turn-off angle are formulated from a voltage equation and feasible design ranges are suggested with variable speed.
Semi-analytical study of 3 kinds of axial flux PM actuator
Authors: Jennane J. , Fadli N. , Charpentier J.-F. , Quesada J. Ríos
Published: December 2018

This paper deals with the study of discoidal Permanent Magnet machines using a method of field calculation based on the magnetic charges theory. This fast calculation method enables a systematic study of these devices. The presented method has been validated by a comparison with the classical FE method. Three kinds of discoidal machines are studied and compared. The first is a classical machine with axially magnetized magnets with iron stator and rotor cores. The second and third use simple Halbach array configurations for the magnets with iron and ironless rotor core. This study illustrates the interest of the Halbach structures for this type of device.
Use of the superconductor magnet to the magnetic separation some selected problems of exploitation
Authors: Cieśla Antoni
Published: December 2018

Superconductor separators are a new generation of magnetic separators; a DC superconductor electromagnet may be used as a source of magnetic field. It creates, among other things, a chance to reject weak-magnetic particles – first of all extra small ones (the basic problem for beneficiation of useful minerals). The subject of the following considerations refers to one from several possible constructions: a matrix high-gradient separator equipped with the DC superconductor electromagnet. Some practical aspects of the construction of the device in laboratory scale as well as the problems of exploitation conditions of the separator are presented.
Experimental study on active seat suspension for a small vehicle
Authors: Oshinoya Yasuo , Arai Hajime , Ishibashi Kazuhisa
Published: December 2018

To improve riding comfort of driver's seat, we have proposed active suspension system for heavy duty truck. In this study, the control mechanism of the active seat suspension was designed for a small vehicle such as community car with using the optimal control method. The operability improvement for senior citizens, the vibration isolation for babies and the riding comfort improvement on the unpaved road can be expected. In order to examine the effectiveness of the system, experiments were performed.
Performance analysis of butt jointing in remountableHT_C superconducting magnet
Authors: Ito Satoshi , Hashizume Hidetoshi , Yamauchi Takeshi
Published: December 2018

For a future design of fusion power plant, concept of remountable SC magnet is proposed to improve cost performance. In this concept butt jointing of HT_C SC is used as jointing method and contact force can be obtained from electromagnetic force induced by self magnetic field of the magnet. Evaluation of performance of butt jointing with laminated SC tapes is performed to demonstrate feasibility of the remountable SC magnet experimentally. The result shows that the jointing resistance is almost in inversely proportional to the contact area and dependent on transport current. Numerical analysis is carried out to explicate the resistance dependence. The numerical results, however, shows difference from the experimental one. Further, evaluation of electromagnetic force is carried out to prove that the contact stress can be obtained only by electromagnetic force.
Low frequency electromagnetic waves in periodic structures
Authors: Guenneau S. , Geuzaine C. , Nicolet A. , Movchan A.B. , Zolla F.
Published: December 2018

The propagation of electromagnetic waves in three-dimensional periodic structures is studied here using the finite (edge) element method. The use of the Floquet-Bloch theory leads to special boundary conditions. In the quasi-static limit, we obtain the effective properties for a periodic array of dielectric spheres and compare these numerical results with two other homogenization approaches, namely Clausius-Mossotti theory and two-scale method.
Computer simulation of magnetic levitation of thin steel plate in consideration of large scale transient response
Authors: Yokoo Koichiro , Oshinoya Yasuo , Ishibashi Kazuhisa , Marunaga Kazuo
Published: December 2018

This paper describes how to simulate magnetic levitation of a thin steel plate by using electromagnets. Since the levitation system is essentially unstable, the plate is levitated by controlling the attractive magnetic force produced by the electromagnets with feedback signals: the displacement and velocity of the plate and the current of the electromagnet. As the magnetic force is the same regardless of the current direction, a bias voltage is necessary for supplying an initial current to the electromagnet. The motion equation of the plate is solved by the finite difference method. The magnetic force is obtained by using the finite element method. In this paper, we study how to improve the control performance, which becomes better by adding a current feedback and adjusting the bias voltage.
Comparison between two models of magnetic hysteresis accounting for stress
Authors: Bernard Yves , Ossart Florence
Published: December 2018

Two models of hysteresis including the influence of an elastic stress on the magnetic behavior of the material are analyzed. They are shown to have different properties, but comparable accuracy. The Preisach model needs a large amount of experimental data, but is very general, whereas the internal variable model uses few parameters, but can not fit any shape of hysteresis loops. The advantages and drawbacks of the two approaches are illustrated in the case of two electrical steels: a 0.5 mm thick Fe-3%Si alloy and a 0.4 mm thick Fe48%-Co48%-Va2% alloy.
New concept of the first wall to reduce MHD pressure drop
Authors: Hashizume Hidetoshi , Usui Yoshiaki , Kitajima Sumio , Sagara Akio
Published: December 2018

Numerical analysis of MHD flow in rectangular channel is performed to evaluate the performance of remountable first wall with liquid blanket like Li or Flibe, where fabrication and maintenance of the system become extremely simplified. Four-channel model is used to calculate the MHD pressure drop in variously coated channels. The effect of crack existence in the coated layer of flow channel on the MHD pressure drop is also evaluated for real usage. The numerical results indicate that some amount of crack existence is allowable, which shows possibility to apply the first wall concept to future fusion reactor design.
Bridge design of interior permanent magnet motor for hybrid electric vehicle
Authors: Lee Kab-Jae , Kim Sol , Lim Seong-Yeop , Lee Ju
Published: December 2018

This paper presents the bridge design of interior permanent magnet(IPM) motor for hybrid electric vehicle. Among design parameters, the bridge is an important factor because it affects a mechanical cracking by centrifugal force and electrical performances. When we design the bridge of IPM motor, a mechanical stress analysis should consider a centrifugal force and electromagnetic forces. The total of above forces is a stress source of the bridge. Electromagnetic forces are calculated by the finite element method with Maxwell stress tensor method. The Von Mises criterion is applied to the mechanical stress. As the electromotive forces are considered, the bridge width can be reduced 43% compared with the bridge width considering only the centrifugal force.
Global linearization of non-linear state equations
Authors: Jordan Andrzej J. , Nowacki Jerzy P.
Published: December 2018

The global linearization method is used to solve multivariable non-linear state equations. This method makes use of a simple and invertible change of coordinates based on global diffeomorphism. A full agreement of the solutions of the linear and non-linear models was obtained. Two examples of practical application of this method have been presented: the first – a non-linear model of a DC drive system, and the second – an electrical circuit with a non-linear diode.
Software tool for conception and optimisation of permanent magnet synchronous machines
Authors: De Cecco Eric , Marchand Claude , Besbes Mondher
Published: December 2018

The aim of this paper is to describe a software tool for conception and optimisation of permanent magnet synchronous machines associated to their converters, using a coupled model for magnetic field and electrical circuit equations. In this paper, the emphasis is on the specifications of the tool: modularity, adaptability and evolutive capacity.
Calculation of inductances in permanent magnet type transverse flux linear motor
Authors: Lee J.Y. , Hong J.P. , Jang J.H. , Kang D.H.
Published: December 2018

The design and analysis of electrical machines often require analytical models for performance assessment and system simulation. Inductance is one of important parameters of these models. In this paper, the calculation methods of apparent and incremental inductances are introduced for a transverse flux linear motor (TFLM), which has a peculiar coil shape. To consider nonlinearity of the inductances according to current and magnetic materials, nonlinear analysis is performed by 3-dimensional equivalent magnetic circuit network (3D EMCN). The calculation method has been verified by test results.
Multiobjective design optimisation: A microeconomics-inspired strategy applied to electromagnetics
Authors: Di Barba P.
Published: December 2018

In the paper the method of gradient balance is revisited from microeconomics and proposed in electromagnetics as an alternative formulation of a design optimisation problem, characterized by two objective functions; this formulation exploits the design space directly. Accordingly, a numerical procedure to approximate a non-dominated solution was implemented; after validating the numerical procedure by means of an analytical benchmark, a field-based case study was developed.
Vibration suppression of a structure with an MR damper using a neural network controller
Authors: Shiraishi Toshihiko , Nakaya Noriyuki , Morishita Shin
Published: December 2018

Semi-active vibration control has attracted a great deal of attention taking advantage of vibration reduction effect, control stability and effective energy consumption. MR dampers are known as one of semi-active control devices, which consist of controllable fluids in fixed orifice dampers. In this paper, response reduction is numerically and experimentally conducted on a building structural model equipped with an MR damper on the first story. It is difficult to deal with time variation of properties and nonlinearities of MR dampers and structures. It is another problem that optimal damping may be varied according to frequency and magnitude of components of a wave input to structures. In order to deal with these problems, neural networks are applied to the vibration control system. As a result, it is shown that the displacement of the top story of the structure is highly reduced using the neural network control system.
Asymptotic analysis for steady mode III crack growth in a piezoelectric sandwich composite
Authors: Zhou Zhi_Dong , Nishioka Toshihisa
Published: December 2018

In this paper a steady semi-infinite mode III crack growth along the midplane of a piezoelectric layer sandwiched between two identical half spaces is considered. The Fourier integral transform is used to reduce the mixed boundary value problem to the Wiener-Hopf equation by introducing an auxiliary function. The complete stress and displacement distributions along the crack line can be obtained and further the dynamic stress and electric displacement intensity factors and the energy release rate are presented in explicit form. The results show that the crack propagation speed and coupled material constants influence on the dynamic stress and electric displacement intensity factors, moreover the dynamic energy release rate is dependent on the crack propagation speed and material 2 for this geometry.
Theoretical modelling of a conducting crack in a magnetoelectroelastic solid
Authors: Tian W.-Y. , Rajapakse R.K.N.D.
Published: December 2018

A theoretical study of a magnetoelectroelastic composite plane with a single conducting crack is presented. Crack is assumed to be arbitrarily oriented with respect to the poling direction of the medium. General solutions for fully coupled magnetoelectroelasticity expressed in term of complex potential functions are used to formulate the problem. The formulation of a conducting crack is reduced to a classical Riemann-Hilbert problem and explicit analytical solutions are derived for the field intensity factors, total and mechanical energy release rates and crack tip hoop stress. The formulation is then extended to obtain common fracture parameters of an arbitrarily oriented permeable crack. Selected numerical results are presented for a conducting and a permeable crack in magnetoelectroelastic composite BaTiO _{3} -CoFe _{2} O _{4} . It is found that crack orientation, volume fraction of piezoelectric phase and magnitude of electro-magnetic and mechanical loading have a significant influence on fracture parameters.
Influence of the magnetic susceptibility of the particles on the magnetic filter performance
Authors: Herdem S.
Published: December 2018

The average value of the magnetic susceptibility of the particles occurring in the real technological liquids and captured by magnetic filters and separators is not known at the beginning of the filtration process. Since the magnetic susceptibility of the captured particles varies with the magnetic field intensity, the relation between the magnetic field intensity and the magnetic filter performance in the magnetic filtration equation cannot be assumed exactly correct. This problem can be overcome by using the average value of the magnetic field in the pores and determining the average susceptibility of the particles in this field. Approximate results can be obtained for the properties of the filtration process by considering the magnetic properties of the filter elements and the properties of the magnetic field occurring in the pores of the filter matrix. The obtained results make possible to determine the technological properties of the magnetic filtration and separation systems, and hence to optimize and control easily of the filtration processes.
Regularised synthesis of the magnetic field using the L-curve approach
Authors: Krawczyk-Stando Dorota , Rudnicki Marek
Published: December 2018

Ill-posed problems occur frequently in science and engineering. Regularisation methods are used for computing stable solutions to the ill-posed problems. The purpose of regularisation is to incorporate more information about the desired solution in order to stabilise the problem and find a useful and stable solution. The most common and well-known form of regularisation is that of Tikhonov in which the regularised solution is searched as a minimizer of the weighted combination of the residual norm and a side constraint. The weight given to the minimisation of the side constraint is controlled by the regularisation parameter. Thus, the regularisation parameter is an important factor that controls the quality of the regularised solution. A good regularisation parameter should fairly balance the perturbation error and the regularisation error in the regularised solution. There are several methods for choosing regularisation parameter. In the paper we demonstrate another method: the L-curve criterion for choosing the regularisation parameter. The L-curve is a plot of the seminorm of the regularised solution versus the corresponding residual norm thus expressing the compromise between minimisation of these two terms. The L-curve method efficiency is demonstrated on examples of synthesis of magnetic field of different kind.
Exact solution for mode III cracks in a magnetoelectroelastic layer
Authors: Wang B.L. , Han J.C. , Mai Y.W.
Published: December 2018

In this paper, we developed a closed-form solution for anti-plane mechanical and in plane electric and magnetic fields in a magnetoelectroelastic layer of finite thickness. Explicit expressions for the stresses, electric fields, and magnetic field, together with their intensity factors and the energy release rate are obtained for the extreme cases of impermeable and permeable crack assumptions, including electrically impermeable and magnetically permeable crack assumption, electrically permeable and magnetically impermeable crack assumption, fully impermeable crack assumption, and fully permeable crack assumption. It is shown that the crack face electromagnetic boundary conditions have strong influence on the crack tip electromagnetic field intensity factors and energy release rate. The stress intensity factor, however, does not depend on the crack electromagnetic boundary condition assumptions. Using the basic solution for the single crack problem, solutions for the problems of two collinear cracks, a periodic array of parallel cracks, and two periodic arrays of parallel cracks are also given.
Metallic thin film composites with shape memory alloys for microswitches and tactile graphical displays
Authors: Vitushinsky Roman , Khelfaoui Fadila , Schmitz Sam , Winzek Bernhard
Published: December 2018

A new mechanism to switch thin film actuators between two stable states has been developed. Bistable membrane switches can be realized by snap-dome shaped metallic foils which are coated on opposite surfaces with Ti(Ni,Cu) and (Ti,Hf)Ni respectively whereby the narrow hysteresis of Ti(Ni,Cu) is within the broad one of (Ti,Hf)Ni. If both SMAs are martensitic or both are austenitic, they apply similar forces on the intermediate foil and the shape of the membrane remains constant. However, if one of them is austenitic and the other one martensitic, the austenitic one determines the curvature of the membrane. Switching is possible by two different heat pulses. Therefore, energy is only required to change the state of the membrane. The new mechanism is described and first successful processing steps are presented. The mechanism allows the fabrication of microswitches and tactile displays.
Ferromagnetic shape memory microscanner with large deflection angles
Authors: Brugger D. , Kohl M. , Krevet B.
Published: December 2018

A Ni-Mn-Ga microscanner has been developed as a test platform for an experimentally study of the coupled thermal, magnetic and mechanical performance of ferromagnetic shape memory alloy (FSMA) actuators. The microscanner is designed as a double-beam cantilever of a magnetron sputtered Ni-Mn-Ga thin film. The chemical composition of the cantilever is adjusted to simultaneously induce a ferromagnetic and a martensitic phase transformation upon heating. In the presence of a magnetic field, this system can be actuated in two opposite directions by making use of either magnetic or shape recovery forces. Experimental stationary deflections of the actuator are analyzed by finite element simulations. The shape recovery and magnetic forces are calculated along the trajectory of the actuator allowing the determination of stationary equilibrium positions.
Review of in vitro studies on the biocompatibility of NiTi alloys
Authors: Ponsonnet L. , Tréheux D. , Lissac M. , Jaffrezic N. , Grosgogeat B.
Published: December 2018

Nickel-Titanium (NiTi) alloys exhibit special mechanical properties known as shape memory effect and superelasticity. The first effect relates to the fact that after deformation at low temperature, the material regains its original shape after heating. The second effect denotes an unusual flexibility of the material that is far greater than the flexibility of common metallic materials. These properties can be put to excellent use in various biomedical applications, such as orthodontic wires, orthopaedic implants for osteosynthesis, stents for various applications, bone substitution materials and experimental systems for scoliosis correction. The purpose of the present review is to analyze in vitro NiTi biocompatibility compared to other titanium alloys. The problem of Ni's possible toxicity is discussed. Corrosion properties in an oral environment are investigated. The effect of surface chemical composition and surface roughness on cell adhesion, morphology and proliferation is shown as an example. Sterilization is taken into account and its influence on roughness and mechanical properties, chemical composition, wettability and bacterial adhesion inhibition is evaluated. The conclusion is that NiTi is at least as biocompatible as conventional titanium due to the TiO _{2} oxide layer, and that only in special chemical conditions can Ni diffuse out of the NiTi material.
Hybrid modeling for the active control of multibody smart structures – modeling validation
Authors: Matichard Fabrice , Gaudiller Luc
Published: December 2018

This study deals with the modeling of multibody smart structures including distributed piezoelectric actuators and sensors. The hybrid modal-nodal (HMN) modeling method proposed for modal active control is based on a modal modeling of structural behavior and a nodal modeling of piezoelectric behavior independent of each other. The electromechanical coupling modeling is validated by applying it to a clamped-free smart beam model. The accuracy of the HMN method is shown by comparison with other modeling methods and experiment. Then, a hub-beam application including electromechanical couplings as well as mechanical couplings between rigid body modes and flexible modes is described. The corresponding modeling, the experiment and the comparison of the results are presented. This application demonstrates that the HMN method provides an appropriate and efficient solution for the predictive modeling and control of multibody smart structures with complex assemblies and geometries.
Potentiometric biosensors based on ISFETs and immobilised cholinesterases
Authors: Dzyadevych Sergei V. , Arkhypova Valentyna N. , Martelet Claude , Jaffrezic-Renault Nicole , Chovelon Jean-Marc , El'skaya and Anna V. , Soldatkin Alexey P.
Published: December 2018

This paper describes authors' achievements in the development, investigation, and application of cholinesterase biosensors based on ISFETs. Various biosensors for determination of concentrations of different toxic substances (organophosphorous and carbamate pesticides, hypochlorite, glycoalkaloids) were designed on the basis of reversible and/or irreversible enzyme inhibition effects. The main analytical characteristics of the biosensors developed have been studied under different conditions and optimal experimental protocols for toxic substances determination have been proposed. Most of these biosensors show a high reproducibility and a good operational and storage stability. A quite good correlation with results obtained through routinely used standard methods as HPLC has been shown.
Solution of elliptic inverse problems using integral equations
Authors: Kharytonov Alexander
Published: December 2018

The solution of inverse boundary problems are considered. One must determine the coefficients or functions of elliptic differential equations inside the domain Ω from a knowledge of boundary conditions (the Cauchy data) on the boundary ∂Ω. The algorithms for the numerical solution of such problems are presented.
Low – frequency electromagnetic scattering by a perfectly conducting torus. The Rayleigh approximations
Authors: Venkov George
Published: December 2018

The paper investigates the propagation of a plane electromagnetic wave in the exterior of a perfectly conducting torus. Using the fact that in toroidal coordinates the vector Helmholtz equation does not admit separation of variables we apply the low-frequency method and the electromagnetic scattering problem reduces to a sequence of potential problems. The incomplete R-separation leads to infinite system of three-diagonal form. More precisely, the boundary conditions for the magnetic field produce a third-order recurrence relations, due to the Riemannian radical and the non-orthogonality of the toroidal harmonics in the angular variable. The three-diagonal infinite systems of linear algebraic equations are solved analytically via the appropriate use of finite continuous fractions.
Modeling of transport phenomena of nano-particles in biological media in electromagnetic fields
Authors: Zhou Shu-Ang , Uesaka Mitsuru
Published: December 2018

This article introduces a theory of studying transport phenomena of charged or polarizable nano-particles in some biological media in electromagnetic fields. The mathematical formulation of the transport phenomena given in the article is based on systematic usage of non-equilibrium thermodynamics and continuum electrodynamics for thermodynamic open systems. Some complete sets of fundamental equations for the analyses of the transport phenomena fulfilling basic physical laws are derived in the article. Possible effects of viscosity, viscoelasticity, heat and mass flow, electric diffusion current and polarization in either fluid or solid-like mixtures are characterized properly in our theoretical model, including their coupling effects. The theory may be used not only for analyzing transport phenomena of some nano-drug carriers in drug delivery systems, but also for studying molecular transport problems in some engineering applications. The formulated theory is generally nonlinear, which may however be linearized in some cases. Illustratively, a coupled electrodiffusion wave problem is analyzed with a linearized model and its solution is discussed with some possible applications outlined.
Application of Model Predictive Impedance Control (MPIC) in analysis of human walking on rough terrains
Authors: Karimian M. , Towhidkhah F. , Rostami M.
Published: December 2018

By using Model Predictive Impedance Control (MPIC), two essential questions about human walking control have been considered in this paper: Which parameters are controlled by the control system and what strategies are applied? As a general method, MPIC was proposed as a possible model for controlling human movements in the previous paper of one of the authors [1] and it was also applied to periodic movements such as walking [2]. According to the acceptable results of primary experiences, a more realistic walking model is presented in this paper to be controlled by MPIC strategy. A 3-dimensional 5-link simulated walking robot with 8 degrees of freedom in sagittal and lateral planes is employed to be analyzed while being controlled on an irregular condition, like ascending and descending stairs. The objective of the controller is to optimize the energy consumption, vertical orientation of the body, and forward speed of its center of mass. Visual feedback effect is applied when the robot targets specific footprints over the walking terrain. Each optimization sequence has been applied during the prediction horizon with one human step duration. The results have been animated for comparison with natural walking of a human in similar conditions.
Optimization of accumulating sequence for solid freeform fabrication system
Authors: Min Sanghyun , Um Taijoon , Joo Youngcheol , Kong Yonghae , Chun Ingook , Kim Seungwoo , Bang Jaecheol
Published: December 2018

Solid freeform fabrication system has recently been used in many practical areas for fast manufacturing of a concept model. Prototype model can easily be made using a solid freeform fabrication system at the product developing step for checking and correcting the probable design error. The system considered for this paper basically consists of laser cutting apparatus and material handling equipment. The basic principle of the process is such that 3D CAD data is sliced into thin 2D layers, each slice is cut by laser source along the profile of the 2D layer information and the slices are stacked for sintering in a furnace. Material for the process initially was raw ceramic green tape and becomes hard enough for practical use after sintering.
Conducted EMI reduction of PWM inverter for AC motor drive systems
Authors: Kim Lee-Hun , Yu Jae-Sung , Lee Won-Cheol , Won Chung-Yuen , Hahm Nyon-Kun , Kim Gyu-Sik
Published: December 2018

Much attention has been given to EMI problems generated in variable speed AC drive systems. Zero switching states of PWM inverter generate large common mode voltage. This paper focuses on the voltage modulation in order to mitigate common mode voltage. It shows that the common mode voltage can be reduced much more by choosing the PWM switching method in which each carrier wave is 120 degrees out of phase. To demonstrate the practical significance of our results, we presented some simulation and experimental results.
Motor fault detection method for vibration signal using FFT residuals
Authors: Lim Ho Soon , Chong Kil To , Su Hua
Published: December 2018

Induction motors play an important role in the safe and efficient operation of industrial plants because they are considered inherently reliable due to their robust and relatively simple design. Therefore, there is an indispensable need to monitor their health and performance. And the detection and diagnosis of motor faults is the base to improve the efficiency of industrial plants. In this paper, a residual model-based fault detection method is proposed for steady state vibration signals of induction motors. The stationary signal had been extracted from the entire signal using data segmentation. The reference model in spectra is obtained statistically to represent the healthy condition. The ratio of RMS of residuals is used as a fault indicator for detecting motor faults. The effectiveness of the proposed approach in detecting a wide range of mechanical faults is demonstrated through the experiments applied on an 800 hp motor, and it is shown that a robust and reliable induction motor fault detection system has been produced.
Optimal filtering of EEG signals with several gestures
Authors: HO Choi Kyoung , Sasaki Minoru
Published: December 2018

Every movement, perception and thought we perform is associated with distinct neural activation patterns. Neurons in the brain communicate with each other by sending electrical impulses that produce currents. These currents give rise to electrical fields that can be measured outside the head. It shows some variation on the electroencephalographic signals. In recent devices, the EEG signals measured from head surface are a sum of all the momentary brain activation. With these EEG signals, it is difficult to distinguish the patterns correlated with a certain event from the signals. However, the system must discriminate some patterns with some events especially for any kind of device as a brain control interface system. In this experiment, the sensory-motor cortex of humans has been extensively studied. Activation related to several movements on both sides of the sensory-motor cortices in imaginary. The activation patterns during imagination of several movements resemble the activation patterns during preparation of movements. The result represents the system based on the optimal filters discriminated at least 60% of mental imageries.
Preisach modelling of ferroelectric behaviour
Authors: Bernard Yves , Maalej Abdel Halim , Lebrun Laurent , Ducharne Benjamin
Published: December 2018

The aim of this paper is to present a one dimensional Preisach [1] modelling of the hysteretic behaviour of the electrical polarization P versus the electrical field E. This model is applied to a soft ferroelectric material (classified P188) and it is shown that the piezoelectric butterfly loop of the mechanical stress S versus E is deduced from the P(E) behaviour. The centred cycles method [2] is used to obtain the Preisach's density. With this method only a few experimental cycles can be used to characterize the hysteretic P(E) behaviour.
On-line cure monitoring of polyurethane foams by dielectrometric viscosity measurements
Authors: Vandenbossche Lode , Dupré Luc , Melkebeek Jan
Published: December 2018

Low-frequency dielectric measurements are applied as an experimental method to monitor the evolution of the overall curing process of one-component polyurethane foams. The electrical resistivity, correlated to the ion viscosity of the curing foam, is measured continuously throughout the curing process. An automated experimental set-up was developed and quantitative specifications about the curing speed, the degree of cure and the end of the curing process are introduced. The influence of foam controlling additives and application methods on the curing process is investigated.
Characterization of the passive mechanical properties of large intestine
Authors: Higa Masaru , Luo Yun , Okuyama Takeshi , Takagi Toshiyuki
Published: December 2018

This paper presents experimental data obtained from the in vivo compression of the large intestine of goat and describes its non-linear and viscoelastic mechanical properties. Data were obtained from compression tests on the large intestine of an anesthetized goat using a stress-strain acquisition equipment. The tissue was first compressed with a constant rate then hold at a maximum strain for 300 seconds. All the results demonstrated highly non-linear stress-strain behavior during the compression phase. The stress versus time curve during the relaxation phase was obtained and the reduced-stress relaxation function was applied. This paper serves as a preliminary report on the mechanical properties of large intestine based on in vivo experimental data.
Simulation of a new hybrid particle swarm optimization algorithm
Authors: Luo Ping , Ni Peihong , Yao Lihai , Ho S.L. , Ni GuangZheng , Xia Haixia
Published: December 2018

In this paper, a new hybrid Particle Swarm Optimization algorithm is introduced which makes use of the characteristics of Simulated Annealing method, and the crossover and mutation operations of Genetic Algorithms. Simulation results demonstrate that the proposed algorithm observes faster convergent rate for a certain class of optimal problems.
Coupled magnetic equivalent circuits and the analytical solution in the air-gap of squirrel cage induction machines
Authors: Ghoizad Hooshang , Mirsalim Mojtaba , Mirzayee Mehran , Cheng Weiying
Published: December 2018

In this paper a new method is presented to couple an analytical magnetic field solution of the air-gap of an induction machine with magnetic equivalent circuits method used to model the rest of the machine. The proposed method eliminates the need for complex static and dynamic mesh generation process in the air-gap. Therefore, the modelling of rotor motion becomes simpler and more accurate.
Laser dental hard tissue ablation: Comparison Er-lasers and scanned ultra-short pulse laser
Authors: Wieger Verena , Straßl Martin , Wintner Ernst
Published: December 2018

Laser treatment of dentine was performed with two free-running Erbium laser systems operated at 3 W average power, and a mode-locked 12-ps Nd:vanadate laser at an average power of 3.5 W. Mean ablated volumes per laser pulse were determined by means of a three-dimensional digital evaluation method. The temporal pulse profiles of the Erbium systems was analysed to explain the ablation rate results. Additionally, the morphology of the laser treated surfaces was examined.
Contributions in the magnetic energy storage devices shielding and energy confinement
Authors: Tuleasca Ioan , Kacprzak Dariusz , Ohji Takahisa
Published: December 2018

A magnetic energy storage system made in an ellipsoidal enclosure and associated variable height superconductive coils is analysed and a comparison with other systems possessing the same superconductive material volume V_{s} and operating current I is performed. Two sets of geometrical dimensions are proposed, one associated with V_{s} =0.01 m ^{3} and I=80 A and the other corresponding to V_{s} = 1.437 m ^{3} and I=540 A. An efficiency evaluation dependency W_{m}/V_{S} −V _{Threshold}/V_{Overall} , taking into account the safety magnetic field threshold B_{Threshold} =0.5 mT distance, is introduced. The results show a remarkable improvement achieved with the ellipsoidal structure in terms of stored energy as well as better shielding in respect to the equivalent system solenoid.
The computation of mechanical dynamic characteristic in EMS-Maglev system by electro-mechanical equations coupled finite element analysis
Authors: Yao Yingying , Ni Guangzheng , Fang Youtong , Hu Guanzhong
Published: December 2018

The paper describes a fast solving technique for the mechanical dynamic characteristic of electro-mechanical motional systems. Based on a sequence of finite element analysis, and a set of equivalent electrical circuit parameters extracted, the method incorporates electrical equation and vehicle's movement equation into state equations. Through test of an EMS-Maglev system, it reveals that the method gives reasonable results at very low computational costs comparing with transient finite element analysis.
Contactless detection of bending sensitive magnetostrictive bilayers utilizing higher harmonics
Authors: Kosel J. , Pfützner H. , Traxler S. , Kaniusas E. , Mehnen L. , Meydan T. , Vazquez M. , Rohn M. , Merlo A.M. , Marquardt B.
Published: December 2018

The study concerns a novel contactless sensor system based on a multifunctional magnetostrictive bilayer material. The permeability of the bilayer ribbons is sensitive either to bending or temperature. The higher order harmonics which are generated by the bilayer in response to a magnetic interrogation field are detected. Their amplitudes depend on the bilayer's permeability, hence on the quantity to be measured. The detection of the third harmonics proved to be most efficient. The sensor system enabled contactless measurements with a distance up to 1 m using a bilayer of only 80 mm in length and 0.1 mm in thickness.
Optical tissue absorption sensor on the thorax: Possibilities and restrictions
Authors: Kaniusas Eugenijus , Pfützner Helmut , Mehnen Lars
Published: December 2018

The study concerned an optical tissue absorption sensor which, if applied at the chest as a novel region, offers a non-disturbing multiparametric monitoring of all three: cardiac activity, respiratory activity, and changes of the oxyhemoglobin saturation S. Contrary to the standard region (e.g., finger), the chest region yields the respiration activity and accelerated assessment of S, though restricted to relative changes. As a novelty, the mutual interrelations between the respiratory activity and light absorption are discussed. The non-distal sensor could be combined with indispensable thoracic sensors, making distal oxygen sensor redundant if the determination of changes of S is sufficient.
Magnetoelectric materials – New materials for applications
Authors: Grössinger R. , Van Duong Giap , Bueno-Baqués D.
Published: December 2018

A survey of the development of magnetoelectric materials is given. The limitations of single phase materials is shown. The concept of magnetoelectric composites will be discussed. A measuring method based on modulating the dc-field and using a lock-in amplifier for determining the magnetoelectric coefficient is described. Results obtained for a composite of 50% BaTiO _3 and 50%CoFe _2 O _4 are demonstrated.
Multi-objective evolutionary design of mold temperature control using DACE for parameter optimization
Authors: Mehnen Jörn , Michelitsch Thomas , Lasarczyk Christian , Bartz-Beielstein Thomas
Published: December 2018

The design of mold temperature control strategies (MTCS) is a challenging multi-objective optimization task which demands for advanced optimization methods. Evolutionary algorithms (EA) are powerful stochastically driven search techniques. In this paper an EA is applied to a multi-objective problem using aggregation. The performance of the evolutionary search can be improved using systematic parameter adaptation. The DACE technique (design and analysis of computer experiments) is used to find good MOEA (multi-objective evolutionary algorithm) parameter settings to get improved solutions of the MTCS problem. SPO (sequential parameter optimization), i.e., an automatic and integrated approach, which extends DACE, is applied to find the statistically significant and most promising EA parameters.
Concrete rebars inspection by eddy current testing
Authors: Rubinacci Guglielmo , Tamburrino Antonello , Ventre Salvatore
Published: December 2018

This paper is focused on the nondestructive inspection of concrete rebars by using eddy current testing. Many practical low frequency systems are capable of locating and estimating the size of the cross-section of the rebars via calibration charts. Here we develop a quantitative non-iterative imaging method based on a numerical model of the probe-specimen interaction.
Computer supported central nervous system stimulation
Authors: Rattay Frank
Published: December 2018

Multi-channel electrodes are implanted in various regions in man for different medical purposes. Operating in a constant mode most of them surprise by simple stimulation strategies. For example single channel epidural stimulation of the spinal cord allows switching from tonic muscle output to a rhythmic stepping like pattern only by changing the stimulation frequency. However, speech understanding with cochlear implant needs sophisticated processing which can be done by a miniaturized computer behind the patient's ear. Even more complex stimulation patterns are desirable for electrode arrays of retina implants.
Magnetopneumography – Advances in measurement procedure, modeling and inversion using artificial neural networks
Authors: Tomek Jiří , Platil Antonín , Ripka Pavel
Published: December 2018

Magnetopneumography (MPG) uses examination of remanent magnetic field for determination of amount and distribution of ferromagnetic dust respired into the lungs. Experimental physical model and forward computer solver were built in order to provide data for training of neural network inverse model. Refinement of models, gradiometric configurations and inversion techniques is under research.
A mesh-free approach for coupled electromagnetic-mechanical problems
Authors: Cutrupi Vincenzo , Formisano Alessandro , Martone Raffaele
Published: December 2018

A numerical approach to the resolution of coupled electromagnetic-mechanical problems by means of a mesh-free formulation is here proposed. Possible discontinuities are treated by means of a jump function, and full advantages are taken of the capabilities of mesh-free methods in the treatment of deforming domains. In order to highlight the effectiveness of the proposed approach, two quasi-static electromagnetic-mechanical problems in a 1-D and a 2-D configuration are presented.
Development and validation of a 3D model dedicated to eddy current non-destructive testing of tubes by encircling probes
Authors: Reboud Christophe , Prémel Denis , Pichenot Grégoire , Lesselier Dominique , Bisiaux Bernard
Published: December 2018

A numerical model dedicated to the simulation of external eddy current testing (ECT) of tubes from the outer diameter surface has been developed. This paper is focused on the calculation of the primary electric field emitted by a tilted and off-centered encircling probe. Numerical difficulties are overcome by using splines functions for multivariate integration. Final simulation results obtained with the complete numerical model are compared to experimental data in the case of an off-centre probe in conditions close to industrial ones.