bluuebunny/crossref_metadata_2025 huggingface dataset:
Biomimetic study of diving beetle robot propelled by alternating magnetic field
Authors: Sudo Seiichi , Tsuyuki Koji , Matsumoto Tadashi , Yoshikawa Masanori , Watanabe Masahiko , Honda Takashi
Published: December 2018

The purpose of the present paper is to develop the micro swimming robot. The swimming behavior of diving beetle was analyzed by a high speed video camera system. Based on the kinematic analysis of insect swimming, a swimming robot propelled by the magnetic torque was developed. The robot system is composed of a NdFeB magnet and alternating magnetic field. It was found that the swimming velocity of robot depends on the frequency of magnetic field.
Optimal design of ultrasonic motor using evolution strategy and finite element method
Authors: Rho Jong-Seok , Lee Chang-Hwan , Jung Hyun-Kyo
Published: December 2018

Until now, Ultrasonic Motor (USM) have been designed by using some simple analytic equations or the trial and error method. Therefore, existent design methods of the USM have the problems such as the inaccuracy and the inefficiency. For the solution of these problems, we propose the optimal design methodology of a USM by using the Evolution Strategy (ES) and the Finite Element Method (FEM). The L1B4 USM is designed optimally by using proposed optimal design methodology.
Analysis of electromagnetic force of electro dynamic suspension with quasi-three dimensional analysis
Authors: Iwatani Yuu , Torii Susumu
Published: December 2018

In Japan, the electro dynamic suspension (EDS) has been studied. EDS using shorted coils, however, has the disadvantages that the pulsation of lift force occurs and the construction cost becomes high. In order to solve these defects, EDS having a conductive plate has been studied. These studies, however, assume that a plate is infinite. This paper presents the analysis of electromagnetic force of EDS having a finite conductor with quasi-three dimensional analysis.
Identification of the parameters of the modified Lorentz function modelling hysteresis cycle
Authors: Nouicer Abdelmadjid , Latreche M.E.H. , Feliachi M. , Méhasni R. , Boubia M.
Published: December 2018

This paper presents the use of a hybrid algorithm based on the artificial neural networks (ANN) and the genetic algorithms (GA) for the identification of the parameters of the modified Lorentz function from the measured cycles. The principle of the identification is based on the minimization of a function criterion which represents the difference between the measured and simulated cycles.
AC magnetic power loss of rare-earth permanent magnets
Authors: Maeda Yoshitaka , Nakahata Yasushi , Todaka Takashi , Enokizono Masato
Published: December 2018

This paper presents a.c. magnetic power loss values measured on rare-earth permanent magnets. Magnetized permanent magnets are used for the investigation, and the effects of magnetization direction on magnetic power loss are examined. The result shows that the magnetic power loss, when the external magnetic field is parallel to the remanent magnetization direction, is larger than that when the external magnetic field is perpendicular to the remanent magnetization direction.
Induced currents into the human body by cooking induction systems: The new european standard EN 50366
Authors: Scorretti Riccardo , Siauve Nicolas , Burais Noël
Published: December 2018

The dosimetry of the induced currents into the human body by the magnetic field generated by a cooking induction system is studied using the finite element method, in the same operating conditions defined in the recent standard EN 50366. In order to improve the accuracy and reduce the computational time, the problem is splitted into two computations (the radiating system alone, the human body alone) by using a special formulation for the human body.
Fuzzy computation for classifying defects in metallic plates
Authors: Buonsanti M. , Cacciola M. , Calcagno S. , Morabito F.C. , Versaci M.
Published: December 2018

Eddy Current Techniques (ECT) for Non-Destructive Testing and Evaluation (NDT/NDE) of conducting materials is one of the most application-oriented field of research within electromagnetics. In this work, a novel approach is proposed to classify defects in metallic plates in terms of their depth starting from a set of experimental measurements. The problem is solved by means of a system based on wavelets approach applied to extract relevant information on the specimen under test directly from the reading and, then, by implementing Fuzzy Inference Systems in order to determine its depth. Finally, Shannon Fuzzy Entropy as well as Subsethood operators have been taken into account to improve the classification methodology.
Application of a Preisach-type hysteresis model to the magnetic evaluation of material degradation
Authors: Vandenbossche Lode , Duprè Luc , Melkebeek Jan
Published: December 2018

Preisach-based magnetic characterization is applied as a non-destructive method to evaluate material degradation due to metal fatigue. At predetermined interruptions of the cyclic mechanical loading a set of first order symmetric and a set of second order minor magnetisation loops are measured and analysed using both the classical and the moving Preisach model. The evolution of microstructure dependent magnetic features such as the Preisach distribution function, the mean-field parameter k and the local coercive field distribution Q_{c}(h_{c}) is monitored: k increases and the peak value of Q_{c} decreases with the number of stress cycles. Moreover, for both parameters the rate of change is higher during the last 10% of the fatigue lifetime.
Extended Kalman filter for uninterruptible power supplies applied to non linear loads
Authors: Zerouali Sakina , Allag Abdelkrim , Mimoune Souri Mohamed , Srairi Kamel , Hamida Amel Hadri , Féliachi Mouloud
Published: December 2018

An extended Kalman filter and a discrete time adaptive linear quadratic regulator for uninterruptible power supplies are presented. On the control strategy design, the gains are determined by minimizing a cost function which reduces the tracking error and the control signal. An extended Kalman filter identifies and estimates the plant parameters and the unmeasured state variables respectively at different load conditions.
Analysis on the magnetic field saturation effect due to ventilation hole in the core
Authors: Kim Ki-Chan , Ju Lee Ki-Chan
Published: December 2018

The ventilation hole in the core of the inverter driven induction motor with high power, small size and light weight, should be designed for improving cooling capacity. In this paper, the analysis method by FEM in designing ventilation holes is presented by considering the magnetic saturation effect due to ventilation holes.
Modelling of a thin crack in ECT using a-ψ formulation with Whitney elements
Authors: Choua Yahya , Santandrea Laurent , Bihan Yann Le , Marchand Claude
Published: December 2018

A finite element modelling of thin cracks in eddy current testing(ECT) is proposed using an a-ψ formulation with edge and nodal Whitney element discretization. A double layer of nodes is employed on the surface of the crack in order to comply with the right behaviour of the electromagnetic fields. The benchmark problem team workshop n° 15-1 has been solved and the computation results have been compared to the experimental ones.
Analysis of solid rotor induction machines using coupled analytical method and reluctance networks
Authors: Mirzaei Mehran , Mirsalim Mojtaba , Cheng Weiying , Gholizad Hooshang
Published: December 2018

In this article it is shown that a two dimensional analytical method can be coupled with reluctance networks for the analysis of solid rotor induction machines. By combining the advantages of both methods while avoiding their drawbacks, this coupling yields both an accurate and time-efficient computation. The analytical method is used in the solid iron rotor region, while the reluctance networks method is applied to obtain the electromagnetic fields in the stator core. In the air-gap, both methods are implemented through the related boundary conditions. The comparison of the simulation results of the proposed method with the finite element ones shows the high accuracy of the presented method in electromagnetic computations.
MR fluid damper composed of different size of particles
Authors: Kanno Hideto , Shimada Kunio , Ogawa Junji , Inoue Norio
Published: December 2018

Magnetorheological fluid dampers have been utilized in vibration control for buildings and mechanical structures. We have proposed a magnetic functional fluid that composed of micrometers size iron particles and 10 nanometers size magnetite particles in a solvent as an advanced MR fluid. In this paper, three kind of MR fluids consisting of different proportions of particles are investigated.
Influence of a uniform magnetic field on ultrasonic propagation velocities in magnetic fluids
Authors: Motozawa Masaaki , Matsumoto Yoshiyuki , Sawada Tatsuo
Published: December 2018

Experimental results for ultrasonic propagation velocity properties in water-based magnetic fluids are reported. Water-based magnetic fluid samples having 10 wt%, 30 wt% and 40 wt% concentration of magnetic particles were examined. The ultrasonic propagation velocity generally decreases with higher concentrations of magnetic particles, generally increases with increasing external magnetic field intensity and exhibits anisotropy.
Influence of noise on EEG source analysis using space mapping techniques
Authors: Crevecoeur Guillaume , Hallez Hans , Van Hese Peter , D'Asseler Yves , Dupré Luc , Van de Walle Rik
Published: December 2018

In this paper, the space mapping (SM) technique is used for solving the inverse problem of electroencephalographic dipole source localization. By using SM, we obtained an adequate solution with a minimum of CPU-time by combining the accuracy of a fine model with the speed of a coarse model. The performance when solving the inverse problem using SM versus direct optimisation techniques was investigated in the presence of noise in the measured potentials.
Magnetic characteristic analysis of dual-rotor machines
Authors: Ikariga Atsushi , Shimoji Hiroyasu , Enokizono Masato , Mauchi Toru
Published: December 2018

This paper presents a dual-rotor electrical machine, designed with grain-oriented electrical steel sheets and Nd-Fe-B permanent magnets. In order to achieve high performance within limited volume, we have tried to increase the magnetic loading by using rare earth permanent magnets in the dual-rotor construction. The use of grain-oriented electrical steel sheets is preferred instead of usual non-oriented sheets in order to let flow high magnetic flux through the core material, avoiding the magnetic saturation. The two-dimensional vector magnetic properties in the dual-rotor core model are analyzed by using the finite element method with the E&SS modeling. The calculated results are compared with measured results on the prototype machine for verification of the designing.
High-density permanent magnet machines
Authors: Ikariga Atsushi , Shimoji Hiroyasu , Todaka Takashi , Enokizono Masato
Published: December 2018

This paper presents a novel permanent-magnet rotor for surface permanent magnet synchronous motors (SPMSM). In order to achieve larger power of SPMSM in limited volume as small as possible, use of a high-magnetic flux condition in designing is investigated. To generate higher magnetic flux density in the air-gap, a new segment type permanent-magnet rotor is proposed. The magnetic characteristics are analysed in detail with the 2-D finite element method, and the calculated results are compared with the experimental results of the prototype machine. The results show that the peak flux density is doubled and the back-EMF becomes a nearly sinusoidal waveform.
Use of the high temperature superconductors (HTS) to the magnetic separation
Authors: Cieśla Antoni
Published: December 2018

Most likely, magnetic separation will be one of the first industrial areas impacted by high temperature superconductors (HTS) technology and may represent the future migration of magnetic separators to this technology. Design for a more detailed evaluation was chosen based on an iron magnetic circuit in which ampere-turns were supplied by a superconducting BSCC-Ag tape wound coil operating at 77 K. Two configurations for the separator were considered, a ball matrix separator and a wire matrix high-gradient separator. Practical separations will be possible with such system.
Functional electrical stimulation monitoring by bending sensitive magnetostrictive bilayer sensors
Authors: Mehnen L. , Kaniusas E. , Kosel J. , Pfützner H. , Meydan T. , Vazquez M. , Rohn M. , Merlo A.M. , Marquardt B. , Sauermann S.
Published: December 2018

A novel sensor system is presented utilizing bending sensitive bilayers. The sensor system detects the contraction-dynamics of the upper femoral musculature during electric stimulation for diagnostics of muscle fibre recruitment and muscle twitch-dynamics in functional electrical stimulation.
Discovery of giant volume magnetostriction at room temperature in La_{1-x}Ba_{x}MnO_{3} manganites
Authors: Demin Roman , Koroleva Lioudmila , Zashchirinski Denis , Kozlov Aleksey , Mukovskii Yakov , Glazyirin Konstantin
Published: December 2018

Giant volume magnetostriction ω is found in La _{1-x} Ba _{x} MnO _{3} manganites attained of 4 × 10 ^{-4} in a magnetic field H=8.2 kOe near Curie point T_{C} . In La _{0.7} Ba _{0.3} MnO _{3} ω achieves of giant value of 2.54 × 10 ^{-4} at temperature T=300 K. Volume magnetostriction and magnetoresistance exhibit similar dependence on T and H in T_{C} – region that is explained by the presence in these single crystals of magnetic two-phase ferromagnetic – antiferromagnetic state due to strong s-d exchange.
Modeling and control of an electric servo drive with strong restrictions in the control variable
Authors: Kozek Martin , Lorenz Andrea , Kampas Philipp
Published: December 2018

Detailed mathematical model of a DC servo drive is established and validated by measurements. Due to battery power supply, a pulse-width modulated(PWM) voltage signal, and a microcontroller with low sampling rate (typical for embedded systems) a comprehensive switched non-linear description results. Linear and sliding-mode controllers (SMC) are designed for the drive. Robustness with respect to parameter variations and measurement noise is investigated by simulation. In contrast to many other reports the linear controller outperforms the SMC because of the given restrictions in control input and sampling time.
Polishing inner capillary walls by a magnetic compound fluid
Authors: Nishida Hitoshi , Shimada Kunio , Goto Makoto
Published: December 2018

We propose a technique for polishing inner capillary walls made of non-magnetic material utilizing a magnetic compound fluid. The principle and polishing characteristics are discussed. The fluid used has the features of both magnetic fluids and magneto-rheological fluids as it is a mixture of the two. Our polishing system employs a rotating field applied vertically with respect to the capillary in order to best utilize the fluid characteristics. The polishing mechanism involves abrasive particles aggregating at a certain section of the polished wall. Polishing is performed using magnetic pressure and magnetic clusters.
Effect of surface angle on mechanical jointing of HTS
Authors: Yamamoto Yuko , Takami Shohei , Ito Satoshi , Yuki Kazuhisa , Hashizume Hidetoshi
Published: December 2018

For realization of a commercial fusion power plant, the remountable HTS magnet was proposed as one of the technologies to reduce both construction and maintenance costs. The butt joint of HTS cable has been investigated for the concept. In this study, the joint performance is evaluated with changing joint area, normal stress and shear stress on the joint surface to investigate an optimum joint condition. The experimental results show that the joint performance is improved by forming the optimum joint surface configuration where the normal stress becomes large while the shear stress is suppressed to be smaller than the normal stress.
Interfaces removal for time-of-flight eddy current testing: The planar geometry case
Authors: Tamburrino Antonello , Tian Yong , Nair Naveen , Udpa Satish
Published: December 2018

The time-of-flight (TOF), typically associated with wave propagation processes, can be extracted from physical processes governed by parabolic PDE's, such as those occurring in eddy current testing of conductive materials. The main "tool" for extracting the TOF is the Q-Transform, which is an integral transform capable of relating solutions of hyperbolic PDE's to solutions of parabolic PDE's. The extraction of TOF is considerably more complex when the specimen to be tested has material interfaces, as in any realistic situation. Here we develop a technique capable of "removing" the effects due to known material interfaces.
Quantitative evaluation of material degradation parameters using nonlinear magnetic inverse problems
Authors: Kojima Fumio , Fujioka Toshiya
Published: December 2018

New assessment strategies for degradation of magnetic materials are presented. Applying current with low frequency to a probe with magnetic yoke, the detecting signal can be measured by pick-up coil attached with the probe. An inspection model is described by a nonlinear Euler equation in two dimensions with the state dependent magnetic permeability. Inverse analysis for magnetization process is developed with the background knowledge of the inspection model driven by the nonlinear magnetic permeability.
Block-oriented identification of Hammerstein/Wiener-models using the RLS-algorithm
Authors: Kozek Martin , Hametner Christoph
Published: December 2018

A new method for identifying Hammerstein/Wiener models is proposed, where the non-linear characteristic is modelled by a piecewise linear function and the linear dynamic part is represented by a linear transfer function. The parameters of the overall model are estimated by recursive least-squares (RLS), therefore enabling the algorithm to be implemented on-line. Using appropriate validity functions the edges of the piecewise linear characteristic may be smoothed out in order to achieve a better fit. An adaptive algorithm for optimal partitioning of the local linear models is also proposed on the basis of statistical analysis. Using the new approach an efficient and accurate model can be identified.
Non-invasive thermometry for the thermal ablation of liver tumor: A computational methodology
Authors: D'Ambrosio V. , Di Barba P. , Dughiero F. , Mognaschi M.E. , Savini A.
Published: December 2018

The aim of the paper is to propose a computational methodology for the prediction of the temperature of tissues during thermal ablation treatment. The methodology is based on the inversion of measured temperatures and it relies on a finite-element model of thermal field.
Error estimation of calculated ECT signal due to thin crack in a plate using a global approximation of the dipole density
Authors: Pávó József , Maurice Léa , Prémel Denis , Lesselier Dominique
Published: December 2018

The accuracy of the calculation of the signal due to the interaction of an eddy current testing (ECT) probe and a thin crack in a plate is basically depending on the discretization of the boundary integral equation which is modelling the actual physical arrangement. In this paper a solution method is introduced, where global approximation functions are used for proper discretization of the equivalent dipole density on the thin crack surface in that integral framework. Among other items, emphasis is put on the evaluation and control of the resulting numerical error. Using such results the automated discretization of rectangularly-shaped thin cracks analysed by an ECT signal prediction software will be shown to become feasible.
A heat conduction approach to a parallel duct-type energy conversion device utilizing a magnetic fluid
Authors: Shimada Kunio
Published: December 2018

The flow and thermal characteristics in a parallel duct-type energy conversion device utilizing a magnetic fluid under a nonuniform magnetic field were analysed using theoretical equations from heat conduction suggesting a laminar developing flow. The theoretical results regarding pressure difference and temperature distribution were compared with experimental results. The present heat conduction model is capable of explaining the experimental data both quantitatively and qualitatively. Coincidence was found to be independent of the performance of the applied magnetic field, which is an important factor in an energy conversion device.
A study of micro magnetic fluid actuator
Authors: Sudo Seiichi , Yano Tetsuya , Okabe Masayoshi , Komatsu Takane
Published: December 2018

Nobel type of micro magnetic fluid actuator is proposed. The micro actuator is composed of a small NdFeB magnet and kerosene-based magnetic fluid HC-50. Driving principle of the actuator is characterized by wireless operation with the alternating magnetic field. The actuator shows the metronomic motion. Frequency characteristics of the metronomic motion of the actuator are examined using a high speed video camera system.
Nonlinear diffusion of magnetic fields in conductive, ferromagnetic media
Authors: Ifrim Costin
Published: December 2018

As part of a double loop convergent iterative procedure as used in [5,6] a simplified fixed-point based [3] non-linear iterative procedure is presented to solve the diffusion of the magnetic field H. The new technique decreases the computational complexity of the iterative set of linear diffusion problems to be solved at each time step.
Evaluation of HTS butt-jointing performance, focusing on the joint stress distribution
Authors: Takami Shohei , Hashizume Hidetoshi , Ito Satoshi , Yamamoto Yuko
Published: December 2018

As a basic research for development of the remountable HTS magnet, experimental evaluation of the butt-jointing method with BSCCO 2223 HTS cable under the large joint stress is performed. In this experiment an optimum joint stress value, which makes joint resistance minimum, is obviously confirmed at each applied current value. In addition, numerical structural analysis is performed to clarify the stress distribution at the joint surface of HTS cable under the experimental condition. From these experimental and numerical results, the efficient jointing condition is considered to reduce the joint resistance.
Electromagnetic field of worm coils for electromechanical integrated toroidal drive
Authors: Xu Lizhong , Cai Yi
Published: December 2018

In this paper, based on electromagnetic theory and geometrics, the electromagnetic field of the worm coils for the drive is researched. A coordinate system is established and equations of the toroidal helical slots for three phase coils on worm are presented. By means of equation for magnetic vector at any point near coil, magnetic vector near single phase toroidal worm coils is introduced. Hence, the total magnetic vector near three phase toroidal worm coils is obtained as well. Simulation results show: near toroidal worm, as a static current is applied to its one toroidal coil, a toroidal electromagnetic field is formed; when the 3-phase source is connected to the coils of the worm, a toroidal circular rotating electromagnetic field will drive several planets rotate about their own axial. And by means of magnetic forces between teeth of the planet and stator or worm, the rotor will be driven to rotate about its own axial and an output of low speed and large torque can be obtained.
Magnetoelastic stresses in a soft ferromagnetic solid with a hole of arbitrary shape subject to uniform magnetic induction
Authors: Lin Chun-Bo , Chen Shin-Cheng , Lin Hsien-Mou
Published: December 2018

An analytical solution for the magnetoelastic problem of an infinite soft ferromagnetic material with a hole of arbitrary shape is provided in this paper. Using the method of complex variable, such as conformal mapping technique and the analytic continuation, both the magnetic fields and magnetoelastic stresses can be obtained. Explicit solutions of several examples are also provided. Comparison with the degenerate case, such as a crack of which the analytic solutions were provided in the literature, is made to assure that the solution of the present work is general and exact. Numerical results for the tangential magnetoelastic stresses on the surface of an elliptic hole or a hypotrochoidal hole are displayed in graphic form to elucidate the effect of geometry parameters. Moreover, the stress intensity factors with r^{-1/2} singularity on the crack tip are also derived.
Deformable mirror tomography – An alternative imaging technique for inverse scattering applications
Authors: Arunachalam Kavitha , Udpa Satish S. , Udpa Lalita
Published: December 2018

Several microwave tomography techniques have been developed to reconstruct the spatial distribution of the electrical property of penetrable objects. These techniques rely on solving the ill-posed nonlinear inverse scattering problem using field measurements acquired from multiple views at multiple frequencies and incorporate prior information during inversion to obtain a stable solution. Such techniques often employ a linear or circular antenna array with individual elements operating as a transceiver to acquire multiple field measurements for imaging. In this paper a tomographic inversion technique with single fixed transmitter and a deformable mirror is proposed as an alternative to the conventional tomography system. Limitations arising from the use of a single transmitter for acquiring multi-view data for the ill-posed problem are overcome by using a continuously deformable mirror with reflective coating. The continuously deformable mirror controlled by an underlying actuator circuit steers the incident field towards the scatterer for multi-view field measurements. A theoretical analysis of the proposed microwave tomography technique including system design, theory, operating principles and selection of optimal mirror shapes to obtain information rich field measurements are discussed in this paper. Computational feasibility of the proposed inverse scattering technique is investigated for two-dimensional penetrable dielectric scatterer in the presence of measurement noise.
Optimisation of a Magnetic Resonance Imaging RF probe through time reversal with TLM
Authors: Thomas D.W.P. , Vukovic A. , Sewell P. , Benson T.M. , McA. McKirdy D. , Glover P.
Published: December 2018

The feasibility of optimising a loaded Magnetic Resonance Imaging RF probe using time reversal analysis and a time domain electromagnetic solver is demonstrated in this paper. It is shown that the geometry of a Magnetic Resonance Imaging RF probe can be refined to improve the field distribution within a sample. In this novel technique the longitudinal electric field is used as the error term for the field within a biological sample and also as the source function for a time reversal simulation. The output of the time reversal simulation will then indicate how the original probe can be adjusted or supplemented to improve the original field distribution. Two examples are given to demonstrate the utility of this approach. The first is the design of a saddle probe and the second is the design of a microstrip RF coil. Although this approach is limited to lossless structures, the results can still provide a valuable insight for structures and biological loads with significant loss. This is a fast and efficient optimisation method which can lead to novel RF structures.
Plasma reconstruction in tokamaks with linearized approaches
Authors: Albanese R. , Artaserse G. , Mattei M. , Tudisco O. , EFDA Contributors JET
Published: December 2018

This paper deals with the problem of the equilibrium reconstruction in a tokamak. We firstly describe two approaches for the shape reconstruction: the former based on a nonlinear least square minimization with Finite Element Method modelling taking into account the Grad Shafranov equilibrium equation; the latter based on linear multifilament models accounting for the presence of iron, eddy currents in the passive structures, and plasma. A possible unified treatment for shape and current profile reconstruction using both internal and external measurements is then discussed: the nonlinear least square minimization procedure used for shape identification is modified to account for internal measurements and profile shape fitting. A linearized approach is finally analysed making use of Singular Value Decomposition theory. Some results on the JET tokamak are shown and discussed.
Optimization of an actively shielded air-core superconducting transformer
Authors: Cavaliere V. , Cioffi M. , Delli Colli V. , Formisano A. , Marignetti F. , Martone R. , Scarano M.
Published: December 2018

Air-core superconducting transformers incorporate the function of shunt reactors, thus they can be used in high-voltage high-capacity applications. They result lighter than their traditional counterpart while requiring heavy metallic shields. However they may represent an effective alternative to traditional transformers only if the weight and clearance reduction is accompanied by acceptable values of magnetizing current and leakage fluxes. The reduction of the leakage fluxes allows the reduction of the metallic shield size leading to an enhancement of the weight advantage. In addition the value of the mutual inductance should fit the shunt reactor action requirement. These objectives can be achieved by the active shielding technique. The paper proposes to properly design both the transformer and its active shield by means of a combined optimization stochastic algorithm. The procedure outlined is applied to a three-phase transformer layout.
Synthesis method of an inductive sensor using Tikhonov regularization procedure
Authors: Micu Dan D. , Ceclan Andrei , Micu Dan O. , Simion Emil
Published: December 2018

It is proposed a synthesis method of designing an inductive position sensor with Tikhonov regularization procedure. Details about the mathematical modeling and numerical solutions obtained are discussed.
Regularization technique applied to the reconstruction of the interface between two conducting fluids
Authors: Kuilekov M. , Ziolkowski M. , Brauer H.
Published: December 2018

The paper deals with a regularization technique applied to the reconstruction of the interface between two conducting fluids. The reconstruction is performed using a simple genetic algorithm or an evolution strategy. However, both algorithms can give ambiguous results with low cost function values and bad quality interfaces which are far away from optically observed shapes. For avoiding such situations it is implemented a regularization procedure by including in the cost function additional terms depending on the interface parameters. The results of the new approach and the comparison with the previous one are also presented.
Inverse problem solution to evaluate the bioelectric field of fetal heart muscle: Remarks on electrodes placement
Authors: La Foresta F. , Cacciola M. , Mammone N. , Morabito F.C. , Versaci M.
Published: December 2018

It is well know that the evaluation of the bioelectric field generated by the human heart allows an accurate monitoring of the cardiac activity. In fact the human heart can be assimilated to an electric dipole that changes its amplitude and its orientation during the depolarization and repolarization processes of the heart muscle cell: this is the theoretic basis of the modern electrocardiogram (ECG). In fact the ECG is a recording of the electric potential, generated by the electric activity of the heart, on the surface of the thorax. Thus, it is used in cardiological diagnosis, like tachycardia, arrhythmia and other disorders in the heart activation. Recent works have shown that the ECG technique could be employed to evaluate the effects of the bioelectric field generated by a fetal heart muscle in order to obtain the so-called fetal electrocardiogram (fECG). The fECG could be a very efficient way for in utero fetal heart monitoring and pathology detection during the pregnancy. In the last years many authors have studied signal processing techniques in order to obtain the fECG in a non-invasive way, but no-reflection has been shown about the bioelectric field generated by the fetal heart. The goal of this paper is to discuss the bioelectric potential distribution that the fetal heart produces on the mother abdomen during the pregnancy. The authors also show that the electrodes placement on the mother abdomen can be optimized to evaluate the fECG using blind source separation technique.
An interface crack between two dissimilar functionally graded piezoelectric/piezomagnetic material half infinite planes subjected to the harmonic anti-plane shear stress waves
Authors: Zhou Zhen-Gong , Wang Biao
Published: December 2018

In this paper, the dynamic behavior of an interface crack between two dissimilar functionally graded piezoelectric/piezomagnetic material half infinite planes subjected to the harmonic anti-plane shear stress waves is investigated. To make the analysis tractable, it is assumed that the material properties vary exponentially with coordinate vertical to the crack. By using the Fourier transform technique, the problem can be solved with the help of a pair of dual integral equations in which the unknown variable is the jump of displacements across the crack surfaces. These equations are solved by using the Schmidt method. The relations among the electric filed, the magnetic flux field and the dynamic stress field near the crack tips can be obtained. Numerical examples are provided to show the effect of the functionally graded parameter and the circular frequency of the incident waves upon the stress, the electric displacement and the magnetic flux intensity factors of the crack.
Swimming mechanics of dragonfly nymph and the application to robotics
Authors: Sudo Seiichi , Tsuyuki Koji , Honda Takashi
Published: December 2018

This paper concerned with the development of swimming micro mechanism based on the study of swimming functions and mechanisms of the minute organisms. At the beginning, this paper describes the swimming analysis of a dragonfly nymph using the high speed video camera system. It was found that dragonfly nymphs can swim skillfully by reciprocating motions consisting of a power stroke and a recovery stroke. Based on the swimming analysis of the dragonfly nymph, the micro swimming robot with the wireless energy supply system was produced. Driving elements of the micro swimming robot are composed of NdFeB permanent magnet, polystyrene body, and a polyethyleneterephthalate film fin. Frequency characteristics of the micro swimming robot propelled by the alternating magnetic field and small permanent magnet were examined experimentally.
Vibration control of vehicle suspension system featuring ER shock absorber
Authors: Choi Seung-Bok , Han Young-Min , Sung Kum-Gil
Published: December 2018

This paper presents vibration control responses of a passenger vehicle equipped with continuously controllable electrorheological (ER) shock absorbers. As a first step, ER shock absorbers are designed based on the damping force levels and mechanical dimensions required for a middle-sized passenger vehicle. This is accomplished using a graphic user interface(GUI)-based design program which is developed for automotive ER application devices. After evaluating the field-dependent damping force property and controllability on the design program, ER shock absorbers are manufactured and incorporated with the suspension of the quarter vehicle prior to the road test. A skyhook control algorithm is formulated and experimentally realized for the quarter vehicle ER suspension system. Subsequently, the middle-sized passenger vehicle equipped with four ER shock absorbers (two for front parts and two for rear parts), high voltage amplifies and sensors is prepared and road test is undertaken under various road conditions. Control responses are evaluated in both time and frequency domains.
Clinical applications and recent progress of therapeutic artificial organ using moving-actuator mechanisms
Authors: Lee J.C. , Chung J. , Rho Y.R. , Lim K.M. , Kim J.C. , Park J.Y. , Lee D.W. , Choi H. , Lee S.M. , Choi D.S. , Nam K.W. , Lee J.J. , Park J.W. , Choi S.W. , Choi J. , Park C.Y. , Park S.K. , Son H.S. , Hwang C.M. , Kim H.K. , Sun K. , Yoon Y.M. , Lee K.K. , Won Y.S. , Min B.G.
Published: December 2018

Therapeutic Artificial Organs (TAO) are extracorporeal life-saving devices that are used to bridge patients from emergency to surgery and recovery. This paper details the research on TAOs in Korea along with their development as the clinical devices. In the heart and lung area, the artificial heart system (AnyHeart) and the pulsatile heart-lung machine (T-PLS) have been developed. The T-PLS has been used in 400 patients.

In the renal replacement area, the portable hemofiltration machine (C-PAK) and its applications in home renal treatment are currently being tested through animal experiments. The multiple applications of the biomaterials, the electromechanical system designs and their control, the telecommunication technology and medical technology have been combined in the research and development of life-saving artificial organs for critically ill patients.
Damping characteristics of SMA films and their application for passive vibration isolation
Authors: Roh Jin-Ho , Lee In , Han Jae-Hung
Published: December 2018

In applications of shape memory alloys (SMAs) as actuators and vibration isolation devices, understanding of the nonlinear hysteretic response of SMAs is important. The thermomechanical response, especially the pseudoelastic behavior of Ni-Ti SMAs at various annealing temperatures is investigated. The 2-D numerical model of the SMAs is proposed to predict the thermomechanical behaviors of SMA thin film. The methodology to attenuate vibrations of a host structure by using an SMA film is numerically demonstrated. For the damping enhancement, the structure with SMA films bonded onto it is numerically modeled and the effectiveness of SMA on passive vibration isolation is investigated.
Self washing underwear type toilet and its control method using humidity sensor and rotary valve with electric current control
Authors: Nagaya Kosuke , Kojima Takako , Hosoya Syunsuke , Eda Keiichi , Ando Yoshinori , Ge De-Liang
Published: December 2018

A self-washing toilet system suitable for patient care is presented. The system consists of rubber pants that are worn by the patient and sealed by inflation with air. Excrement is flushed from the toilet with water via an outlet tube, and the system is flushed with air to dryness. Control systems are developed for the detection of humidity and urine, and for maintenance of appropriate inflation pressures. The inflation system effectively seals around the thighs and waist without discomfort, and reliably differentiates between natural moisture and urine. The underwear type toilet and control system are constructed and demonstrated experimentally to be applicable, in principle, for practical use.
Theoretical model for crack branching in magnetoelectroelastic solids
Authors: Tian W. , Rajapakse R.K.N.D.
Published: December 2018

A mathematical model is presented to determine the fracture parameters of a finite impermeable crack with one or more branches in a magnetoelectroelastic plane subjected to the remote mechanical, electrical and magnetic loading. An integral equation approach based on the fundamental solution for a generalized dislocation is used to formulate the problem. The problem is reduced to a set of singular integral equations with the dislocation densities along the crack line as the unknown variables. The integral equation system is solved by using numerical quadrature. Selected numerical results are presented to demonstrate the dependence of crack tip field intensity factors on branch length, branch orientation, poling orientation of the medium and type of loading. Numerical results imply that a branch crack cannot propagate in a self-similar manner. Solutions for a crack with double branches show that simultaneous propagation of branches is not possible.
Characteristics of a bistable permanent magnet linear actuator with soft magnetic mover
Authors: Yatchev Ivan , Hinov Krastyo , Trifonov Nikola
Published: December 2018

Modelling and characteristics of a newly developed bistable permanent magnet linear actuator are presented. The permanent magnets are fixed and the mover is soft magnetic one. The driving and the holding force can be varied practically independently as they are mainly formed through different air gaps. Static and dynamic characteristics of the actuator are obtained. The static force characteristics are obtained using finite element method for different permanent magnets, different combinations of the two air gaps and different coil currents. Dynamic characteristics are obtained for actuator with ferrite magnets. The results for static and dynamic characteristics are verified experimentally on a prototype of the actuator with ferrite magnets.
Bending strain in prereacted Nb_3 Sn conductors
Authors: Deviatkin E.A.
Published: December 2018

The bending strain in the Nb _3 Sn composite superconductors can cause degradation of the critical current in a significant portion of superconducting filaments. For a correct estimate of the bending strain in the "react and wind" coil conductors it is necessary to take into account that they can be deformed plastically during insulation and winding processes. Cases of plastic deformation due to the tensile stress in a macroscopically homogeneous multifilamentary composite superconductor the prestress of which is smaller than the yield stress in tension are considered in the paper.
Harmonic plane wave propagation in anisotropic chiral media
Authors: Hillion Pïerre
Published: December 2018

We analyse the harmonic plane wave propagation in a anisotropic chiral medium characterized by a symmetric permittivity tensor, scalar permeability and scalar chiraliry weak enough to make negligible its nonlinear effects. The Fresnel equation is first discussed to get the refractive indices in the two directions of propagation. Then, the propagation of harmonic plane waves is investigated in biaxial and uniaxial anisotropic chiral media as well as the reflection of such a wave on these media. Three Appendices giving the explicit form of the electromagnetic field components in anisotropic chiral media complete the paper.
Model of a multiple-lens, single-fiber system in a compound eye
Authors: Meixner Jessica , Iyer Ram
Published: December 2018

In earlier work, we showed that a simple apposition compound eye can form the hardware basis for a new type of inertial navigation system, that can be used on micro air vehicles. One of the key properties of a simple apposition eye is that it is a low pass, spatial filter. This property had been shown in mathematical models based on Fourier optics for a single lens and single fiber system. However, a simple apposition compound eye usually consists of thousands of lenses called ommatidia. An important question that has not been studied is the effect the presence of multiple lenses have on the angular sensitivity, or in some other words, the bandwidth of the low pass, spatial filter. In this paper, we develop a Fourier optics model for a multiple lens, single-fiber system. We obtain expressions for the intensity distribution near the focus of a single lens due to the presence of neighboring lenses and for the angular sensitivity of the system. Numerical simulations show a less than 10 percent increase in the angular sensitivity, even when five or more lenses are considered to focus light on a single rhabdom in a worker bee and an artificial eye.
A Monte Carlo model for positron emission tomography imaging
Authors: Deng Yiming , McGough Robert J. , Berger Kevin L. , Seamans John L. , Udpa Lalita
Published: December 2018

Patient motion during PET imaging acquisitions can result in distortions and artifacts that make accurate interpretation of the image sets difficult. In an attempt to develop a model-based approach, the feasibility of using Monte Carlo (MC) techniques for developing a probabilistic model for PET imaging is investigated. A two dimensional model and its formulation in the Radon space are presented in the scatter-free, scatter, and random noise situations. The reconstructed results using filtered back projection technique demonstrate the feasibility of the approach for clinical application.
Pulse reflection from a generally dispersive material – TE polarization
Authors: Rothwell Edward
Published: December 2018

The time-domain reflection coefficient for a TE-polarized transient plane wave obliquely incident on the interface between free space and a generally dispersive medium is obtained by computing the inverse temporal transform of the frequency-domain Fresnel reflection coefficient. The result consists of simple functions and a finite number of convolutions of these functions. The result should be useful in time-domain material measurement systems, where the theoretical response of a material is required.
Sizing of long stress corrosion crack from 2D ECT signals by using a multisegment inverse analysis strategy
Authors: Wang Li , Chen Zhenmao , Lu Tian-Jian , Xu Minglong , Yusa Noritaka , Miya Kenzo
Published: December 2018

In this paper, a scheme for reconstruction of a long Stress Corrosion Crack (SCC) from 2D ECT signals is proposed based on a multiple crack segments strategy. The profiles of inner and edge crack segments are reconstructed separately by using signals at different scanning direction. A hybrid scheme of the Conjugate Gradient (CG) method and the advance-retreat method are introduced to reconstruct the crack conductivity and crack size. Several cracks of complicated profile are reconstructed from simulated ECT signals of a conductive SCC model. The numerical results verified the validity of the proposed scheme.
Electromagnetic transducer for the determination of soil condition
Authors: Grimberg Raimond , Udpa Lalita , Udpa Satish S.
Published: December 2018

Determination of soil condition is important for several applications ranging from agricultural to homeland security. This paper presents a novel electromagnetic sensor array, the method for solving its forward problem and the super-resolution algorithm for signal processing to detect conductive objects buried in the ground, by determination of soil condition.
Approximate optimization for maximum efficiency of high speed single phase switched reluctance motor using response surface modelling
Authors: Choi Jae-Hak , Koo Dae-Hyun , Kim Sol , Kim Youn-Hyun , Ahn Joonseon , Cho Chang-Hyun , Lee Ju
Published: December 2018

This paper presents an approximate optimization to maximize efficiency and power factor of high speed Single Phase Switched Reluctance Motor (SPSRM) in vacuum cleaner. Moreover, an optimum design process for SPSRM has been performed with geometric and electric parameters by using Response Surface Methodology and 2-D Finite Element Method that is coupled with the circuit equation of the rectifier and converter. To confirm the propriety of the Finite Element Method and the motor performance, simulation waveforms and experiment waveforms for motor voltage and current were compared.
Optimization for resistive reading probe of electric data storage system with a bit of 50 nm
Authors: Choi Jae-Hak , Chun Yon-Do , Han Pil-Wan , Kim Sol , Kim Youn-Hyun , Ahn Joonseon , Kim Yong-Su , Lee Ju
Published: December 2018

This paper deals with a practical methodology to optimize a reading probe of data storage devices using polarization in electric field. The tip and angle of probe pole between a probe and a medium are adopted and identified as significant design variables that have an effect on the polarization direction. The proposed sensitivity function and optimum resistive reading probe shape in the electric recording devices could be obtained by using Response Surface Method and Finite Element Method.