bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnostics of sub-picosecond electron pulse using the fluctuation method
Authors: Nakamura Kei , Watanabe Takahiro , Ueda Toru , Yoshii Koji , Uesaka Mitsuru
Published: December 2018

Numerical analysis and measurement of longitudinal bunch length of subpico- and picosecond electron beams by the fluctuation method has been carried out at the S-band twin linear accelerators at Nuclear Engineering Research Laboratory (NERL), University of Tokyo. The diagnostics method utilizes a statistical analysis of shot-noise-driven fluctuations in incoherent radiation. Measurements were performed on Cherenkov radiation emitted by∼ 1.0 ps (FWHM), 20 MeV electron bunch. As a result, the fluctuation method indicated 5 times longer than that by the streak camera. The discrepancy was caused by neglecting the influence of the transverse emittance. Then, the influence of the transverse profile upon the measurement was analyzed and discussed.
Numerical simulation of dynamics of radial type superconducting magnetic bearing
Authors: Demachi Kazuyuki , Miura Akira , Sawada Akihiko , Miya Kenzo , Higasa Hiromasa , Takahata Ryoichi , Kameno Hiroo
Published: December 2018

The degradation of rotation speed is one of the most significant problems for the practical use of superconducting magnetic bearing (SMB) for flywheel energy storage system. This is called the rotation loss. This phenomena is caused by the AC magnetic field due to the inhomogeneous distribution of magnetic flux density on the permanent magnet (PM) rotor. In this research, our simulation method was improved so that the 3-dimensional rotational dynamics was taken into account.
AC magnetic shielding characteristic of a YBCO superconductor using magnetic field visualization measurement
Authors: Fukuoka Katsuhiro , Hashimoto Mitsuo
Published: December 2018

The magnetic shielding is used as one of applications of the high- T c superconductor (HTS). Magnetic characteristics of the HTS are not uniform, since it has grain boundaries and cracks (weak links). Thus, the evaluation of the magnetic flux invasion by the flux flow into the HTS is important. In this research, magnetic characteristics of the HTS on AC magnetic field from 1 to 250∼Hz were evaluated. From these experiments, we were able to understand that the polycrystal HTS had high magnetic shielding performance at the higher frequency, even if it contains a lot of weak links.
Self-oscillations in electric circuits with high-temperature superconductors
Authors: Meerovich V. , Sokolovsky V. , Vajda I.
Published: December 2018

The paper presents the experimental results showing a specific behavior of high-temperature superconductors in various electric circuits. Self-oscillations of temperature and current in the superconductor manifest themselves as sharp peaks of voltage across the superconductor on the background of a basic signal. It is shown that these oscillations can also appear when a superconductor is in flux creep regime. In inhomogeneous superconducting samples, the oscillations are associated with cyclic movement of normal or resistive zones.
Effects of high magnetic field on Euglena gracilis
Authors: Tanimoto Yoshifumi , Izumi Syunsuke , Furuta Koichi , Suzuki Tomoe , Fujiwara Yoshihisa , Fujiwara Masao , Hirata Toshifumi , Yamada Sotoshi
Published: December 2018

The effects of high magnetic field on Euglena gracilis Z were examined. When a horizontal magnetic field gradient (ca. 400 T ^2 m ^{-1} ) was applied, living E. gracilis moved to a higher field (positive magnetotaxis), whereas dead one gathered in a lower field. Magnetotaxis was not observed in a uniform magnetic field of 8 T. E. gracilis was oriented almost perpendicularly to the magnetic field regardless of life and death. Magnetotaxis of E. gracilis would be explained by taking into account inhomogeneous magnetic forces on and magnetic orientation of E. gracilis.
Green's function for a piezoelectric layer-substrate structure with a general line defect
Authors: Nowacki J.P. , Alshits V.I. , Radowicz A.
Published: December 2018

The 2D electro-elastic fields in the piezoelectric layer-substrate structure with the general line defect are found. The considered line source consists of the four coinciding straight sources: the line of forces, the charged line, the dislocation line and its electrostatic analogue. Electrically, the surface of the layer is supposed to be either metallized or adjoined to an isotropic dielectric medium. Mechanically, two boundary problems are also considered: the surface is free, and the surface is clamped. The solutions obtained for a general case of unrestricted anisotropy are presented in a form of convergent Fourier integrals. The integrands are implicitly expressed in terms of the eigenvalues and the eigenvectors of the generalized Stroh matrix. Their finding needs additional computing.
Application of GMR line sensor to detect the magnetic flux distribution for nondestructive testing
Authors: Kataoka Yasuhiro , Murayama Shuhei , Wakiwaka Hiroyuki , Shinoura Osamu
Published: December 2018

We have developed a GMR line sensor which can arrange many GMR elements in a line on a polyimide film. This GMR line sensor detects the magnetic field distribution in a plane by only a single scan. We use the multilayer GMR element. This element can detect a magnetic field impress from directions of an element length and an element width. And the GMR line sensor has omnidirectional magnetic sensitivity. We applied this sensor to a nondestructive magnetic leakage flux testing. The output of this sensor does not depend on the direction of leakage flux, therefore, this sensor can detect any direction of defect. Using the GMR line sensor, the shape of the defect will be identified by a single scan.
Dynamic thresholding for automated analysis of bobbin probe eddy current data
Authors: Shekhar H. , Polikar R. , Ramuhalli P. , Liu X. , Das M. , Udpa L. , Udpa S.S.
Published: December 2018

An automated algorithm is presented for the analysis and classification of eddy current bobbin probe data obtained from nuclear power plant steam generator tubes (SGT). This algorithm attempts to find a balance between the two seemingly conflicting requirements of SGT eddy current data analysis, namely, detecting and identifying as many of the actual defects as possible, whilst limiting the number of false alarms to a minimum. Initial results presented in this paper look very promising.
Development and performance of a linear induction motor based on the effect of flux-concentration by eddy currents
Authors: Roy Debabrata , Akiyama Yosuke , Yamada Sotoshi , Iwahara Masayoshi
Published: December 2018

This paper has reported the development and performance of a flux-concentration type linear induction motor (FCLIM) utilizing the effect of flux-concentration by eddy currents. In the developed FCLIM, the slot-leakage flux is reduced and as a result more flux is concentrated into the air gap. The key element of the FCLIM is the conducting plate inserted between the exciting coils in each slot. Thrust characteristics of conventional tubular LIM and FCLIM are compared using the equivalent circuit parameters. Though some losses are occurred in the plate, the overall efficiency of FCLIM is better at higher output force.
Extraction of spectral features of signals under the noisy environment using modification rules and weighting function
Authors: Akita Masanori , Tsuboe Naoki , Midorikawa Yoichi
Published: December 2018

This Paper describes the method for effective extraction of spectral features of signals under the noisy environment. Further examination showed that extraction of the features of signals under the noisy environment is possible using modification of spectral envelopes by rule. In this modification method, vanished valleys of spectral envelopes under the noisy environment are recovered. However, the incorrect valleys are sometimes added and the obtained envelopes have bad influences on performance of systems using these features. In this paper, smoothing functions are used for avoiding wrong spectral valleys by rule and the improvement of performance for extraction of spectral features is shown. Four kinds of smoothing functions are defined and evaluated. Experimental results of pattern recognition using proposed spectral parameters are presented.
Effect of magnet rotator type compensator for linear induction motor for new urban subway
Authors: Fujii Nobuo , Sakamoto Yasuaki , Kayasuga Takeshi
Published: December 2018

The authors have proposed new compensation methods for a solution of the end effect of the linear induction motor (LIM), which is to supply the eddy current with minimum power loss in front of LIM. As one of proposed methods, the magnet rotator type compensator is discussed in the paper. The effect is studied analytically on the LIM parameters used in subways in Japan. The thrust density distribution of the LIM with the compensator clearly shows the improvement in the front region. The thrust and the output kW per input kVA of the LIM at the slip of 0.1 increase by 58% and 45% respectively by using the compensator.
Basic characteristics of new interior permanent magnet linear pulse motor
Authors: Wakiwaka Hiroyuki , Misron Norhisam , Kamiya Akinori , Yajima Hisashi , Tamura Kazuya , Fujiwara Nobuhiro , Hosono Masayuki , Takada Takada Susumu
Published: December 2018

In recent years, linear motors are gaining wide popularity in the field of office and factory automation. Therefore, small and high thrust linear motors are needed. This paper deals with a proposal of a new interior permanent magnet type linear pulse motor and it's characteristics. The thrust density of the interior permanent magnet linear pulse motor is larger compared to the other type linear pulse motors.
Design criteria for brushless dc motors for high-speed sensorless operation
Authors: Zhu Z.Q. , Ede J.D. , Howe D.
Published: December 2018

A design criteria for brushless dc motors for high-speed sensorless operation is described. It is shown that motors can be designed such that the free-wheeling diodes in the power electronic drive have a low conduction angle, while exhibiting high efficiency. Thus, established sensorless commutation strategies based on the detection of the zero-crossing of the back-emf waveform can be employed.
Electromagnetic regeneration of lead acid batteries
Authors: Wieger Martin , Hauser Hans
Published: December 2018

Lead acid batteries loose their nominal capacity by time due to the normal aging and by sulfatation. More than 500 experiments proved that batteries regain more than 85% of their capacity being regenerated by the described electromagnetic procedure. Results on strongly sulfated lead acid batteries with a loss of capacity more than 90% show a success rate of more than 55%. Doing the regeneration with lead acid batteries which are still functional (loss of capacity less than 20%), showed that 95% of the nominal capacity could be achieved.
The least square deviations criterion and inverse-source magnetostatic problems
Authors: Haznadar Z. , Štih Ž. , Berberović S.
Published: December 2018

A procedure for the determination of the distribution of magnetization in an object of interest using measured disturbances of external magnetic field is described in the paper. The object is divided into a finite number of brick-shaped elements and we prescribe uniform distribution of magnetization within each element. The contribution of each element to the total magnetic field may be calculated analytically in terms of unknown coefficients of magnetization distribution. These coefficients are determined from a set of measured magnetic field values by application of the least square deviations criterion. Such an approach enables a priori analysis of stability of computation. The application of the procedure is illustrated by an example.
Inspection of electroplated materials -- performance comparison with planar meander and mesh type magnetic sensor
Authors: Mukhopadhyay S.C. , Yamada S. , Iwahara M.
Published: December 2018

This paper has investigated the possibility of applying nondestructive evaluation technique for finding the defects in electroplated materials. Planar meander and mesh type magnetic sensors have been considered and their relative performance have been compared based on a single criterion that the effective area of the material surface covered by each type of sensor is same.
A Study on the detection of creep damage in type 304 stainless steel based on natural magnetization
Authors: Nagae Yuji , Aoto Kazumi
Published: December 2018

A study on non-destructive technique for creep damage of type304 stainless steel was performed. In this study, we concentrated on the magnetic field change with creep damage. This technique has a possibility that the damage before crack initiation is detected. We report that the results on the magnetic field change during creep damage progress, in order to examine the applicability of this technique based on magnetic field change to time-dependent damage. Though type304 stainless steel is a paramagnetic material, the leakage flux density of creep damaged specimen changes obviously, as compared with that of aged specimen.
Magnetic nondestructive evaluation of degradation of nuclear pressure vessel steels due to mechanical loading
Authors: Sukegawa T. , Uesaka M.
Published: December 2018

We performed magnetic nondestructive evaluation of degradation of nuclear pressure vessel steels due to mechanical loading as a fundamental research. We measured magnetic properties of low alloy steel samples, which were degraded due to tensile and cyclic loads. Magnetic hysteresis curves change depending on the loading conditions. The changes of the coercive force, residual magnetic flux density and permeability were obtained and analyzed in details as a function of the residual strain. Based on the above results, we performed the sensitivity analysis of magnetic property changes for the mechanical load. Finally we concluded that the incremental permeability at H = 0 is the most sensitive index for early degradation due to the mechanical loads. The feasibility of application of this magnetic technique to the evaluation of degradation due to neutron mechanical and thermal loading is now under consideration.
Application of wavelet packet image compression technique to particle image velocimetry
Authors: Li Hui , xTakei Yoshifuru , Saito Yoshifuru , Horii Kiyoshi
Published: December 2018

Our motive of this study is to develop an application of the wavelet packet to PIV image compression processing in order to improve the spatial resolution and reliability furthermore. It was found that the reconstructed PIV image with a lower compression ratio might emphasize particle edges at a relatively high spatial resolution. The reconstructed PIV image with a higher compression ratio may display the large-scale motion of particles and may deduce noisy. In this study, the relative error of the wavelet packet image compression technique was lower than that of the standard wavelet image compression technique. The higher compression ratio of 64:1 can be realized without losing significant flow information in PIV processing. It could say that the wavelet packet could provide a better compression performance than the standard wavelet image compression technique when compressing PIV images.
Smart visualization and computer vision in electromagnetism
Authors: Endo Hisashi , Saito Yoshifuru
Published: December 2018

This paper introduces a novel approach of visualization for electromagnetic fields. Our approach is one of the image analysis methodologies based on the classical field theory, which has versatile capability for image processing, compressing, visualizing, identifying, and animating. A key idea is that each of the pixels representing a digital image is regarded as a kind of potentials in vector fields. Gradient or curl operation of the vector calculus to the image data yields image field vector distribution. Any kinds of images can be represented by well-known partial differential equations. The Poisson and Helmholtz types of equations are possible to represent the static and dynamic images, respectively. In this paper, visualized electromagnetic field images are analyzed based on our image differential equations. The image Poisson equation is possible to reconstruct the original electromagnetic fields with high spatial resolution. The image Helmholtz equation enables us extr action of the parameters characterizing the electromagnetic phenomena.
Magnetic levitation control with real-time vibration analysis using finite element method
Authors: Sase Masanori , Torii Susumu
Published: December 2018

The authors propose the magnetic levitation control of thin steel plates using the real-time finite element analysis of the vibration. This paper describes the concept of the proposed levitation system, the finite element simulation of presuming the displacement, and the applicability from the viewpoint of calculation time.
Finite element eddy current analysis by novel mixed-order vector elements
Authors: Hano Mitsuo , Miyamura Takeshi , Hotta Masashi
Published: December 2018

Three-dimensional novel mixed-order tetrahedral elements are systematically constructed and applied to the finite element analysis of electromagnetic fields. The degree of freedoms of the shape functions assigned on the six edges are essentially independent with each other. The shape functions on the faces and in the volume are not orthogonal with those of the edges. So, the tetrahedral elements proposed in this paper have six parameters to define the shape functions. A smooth eddy current flow in the conductor can be obtained, under the condition not to needlessly increase the total number of unknowns.
TTF Beam dynamics simulation by V-code
Authors: Krassilnikov Mikhail , Novokhatski Alexandre , Weiland Thomas
Published: December 2018

V-Code, based on the Ensemble Model [1], was elaborated as fast and efficient tool for the beam dynamics simulation. The Ensemble Model equations are derived from Vlasov equation and involve the second order moments of the distribution function. The structure of accelerators and the features of the Ensemble Model determine the choice of the object-oriented approach for the code elaboration. Such approach gives an essential advantage in further extension, as the code can be improved continuously by introducing new element classes. The Ensemble Model is valid for any energy range and the V-Code can simulate the entire accelerator. The present beam line database has been developed for the TESLA Test Facility (TTF DESY) accelerator component description. The results of the beam dynamics on-line simulation for TTF injector are presented.
Induction and control of magnetic fluid flow by use of dual-linear motor
Authors: Yamane Ryuichiro , Togashi Kazuo , Chinone Yasuhiro , Park Myeong-Kwan
Published: December 2018

Method to induce and control the flow of the magnetic fluid using a double-decked linear motor is proposed and tested. The upper coil of the linear motor generates the basic traveling magnetic field, and the lower one the second harmonics. When the electric current is supplied to only one of the upper and the lower coils, the induced velocity of the magnetic fluid increases with the increase in the strength and the frequency of the applied electric current. When applied simultaneously to the same or opposite direction, the induced velocity is approximated by the square root of the sum or the difference of the square of each velocity at independently applied electric current, respectively.
Synthesis of electrical networks interconnecting PZT actuators to damp mechanical vibrations
Authors: dell'Isola Francesco , Henneke Edmund G. , Porfiri Maurizio
Published: December 2018

This paper proves that it is possible to damp mechanical vibrations of some beam frames by means of piezoelectric actuators interconnected via passive networks. We create a kind of electromechanical wave guide where the electrical velocity group equals the mechanical one thus enabling an electromechanical energy transfer. Numerical simulations are presented which prove the technical feasibility of the proposed device.
Eddy current testing of concrete structures
Authors: Chady Tomasz , Enokizono Masato , Sikora Ryszard , Takeuchi Kazuhiro , Kinoshita Toshihiro
Published: December 2018

The purpose of this paper is to present the results of observation of concrete damage using a newly developed eddy current sensor and a high performance multi-frequency system. Selected digital signal processing algorithms were applied in order to enhance the obtained signals. The experimental verification of the developed technique is done and the elected results are presented.
Neural network based scalar hysteresis model
Authors: Kuczmann Miklós , Iványi Amália
Published: December 2018

A neural network (NN) model of scalar hysteresis phenomena has been developed for modeling the behavior of magnetic materials. The function approximation ability of NNs has been applied. The virgin curve and a set of the first order reversal branches can be stored preliminary in a system of three NNs. Different properties of magnetic materials can be simulated by a knowledge-based algorithm. Value of differential susceptibility, dM/dH can be expressed in analytical form. Finally hysteresis characteristics predicted by the introduced model are compared with the results of the Preisach simulation technique.
Automatic text summarizing based on sentence extraction: A statistical approach
Authors: Cranganu-Cretu Bogdan , Chen Zhenmao , Uchimoto Tetsuya , Miya Kenzo
Published: December 2018

The present work describes a system for automatic summarizing of texts. Rather than focusing on abstracts -- a hard NLP task of not asserted effectiveness the system produces extracts through selection of most important sentences in the original text. Statistical concepts are involved in order to evaluate the degree of significance of words, groups of words and sentences. Currently both Japanese and English texts can be treated. Procedures for computing importance, information content of sentences and measures of correlation between sentences are implemented. Comments are given on the feasibility of the approach and future developments.
Approximation of the Preisach function using feedforward neural network
Authors: Dotterweich Martin , Szymański Grzegorz , Waszak Michał
Published: December 2018

The nonlinear computations based on the Newton-Raphson algorithm may suffer poor convergence provided that the measured data are employed directly. The aim of this work is to present the method to improve convergence rate of magnetic field simulations taking hysteresis into account. The Preisach model is considered. It is proposed to use the neural network approximator to obtain smooth hysteresis model output. The mathematical representation of the neural network is exploited to obtain analytical expression for derivative of the hysteresis model output. Moreover, taking advantage of the analytical form of the Preisach function, it is shown that speed up in calculations of hysteresis energy losses can be achieved.
A ray tracing approach to model wave propagation in highly multimode graded index optical waveguides
Authors: Sönmez Y. , Himmler A. , Griese E. , Mrozynski G.
Published: December 2018

An approach for modeling wave propagation in graded index waveguides within the validity range of geometrical optics is presented. The method is based on wavefront construction in conjunction with dynamic ray tracing, which are both well known for seismic applications. The objective of this paper is to apply this formulation to the analysis of wave propagation in highly multimode optical waveguides whose index changes are small within the scale of a few wavelengths of the guided light and whose lengths are very large compared to the wavelength. In addition the method is applied to bulk optical components like the Luneburg lens.
Advanced transducer modeling using the finite element method
Authors: Lerch R. , Kaltenbacher M. , Landes H. , Hoffelner J. , Rausch M. , Schinnerl M.
Published: December 2018

An advanced numerical calculation scheme based on finite and boundary elements as well as multigrid methods is presented. This scheme is used for the precise forecast of the dynamical behavior of piezoelectric, electrostatic and, magnetomechanical devices, especially sensors and actuators. Application examples include solenoid valves, piezoelectric source for the generation of acoustic shock waves, magnetic surface acoustic wave (SAW) filters, electrodynamic loudspeakers and magnetostrictive tool actuators.
Network methods in electromagnetic field modelling I: global modelling
Authors: Russer Peter
Published: December 2018

The application of network-oriented methods to electromagnetic field problems can contribute significantly to the problem formulation and solution methodology. The field problem can be systematically treated by the segmentation technique and by specifying canonical Foster representations for the subcircuits. Connection between different subdomains is obtained by selecting the appropriate independent field quantities via Tellegen's theorem. For each subdomain, as well as for the entire circuit, an equivalent circuit extraction procedure is feasible, either in closed form for subdomains amenable of analytical description or via the relevant pole structure description when a numerical solution is available.
Fields and shielding by eddy currents in perforated boxes
Authors: Hahn A. , Kost A. , Jänicke L. , Miethner K.
Published: December 2018

This article describes the influence of gaps on the shielding performance of a box. The investigation has been carried out with the Finite Element Method and especially a method with adaptive mesh generation.
Characteristic analysis of planar motor using the volume integral equation method
Authors: Cho Han-Sam , Im Chang-Hwan , Jung Hyun-Kyo , Chung Tae-Kyung
Published: December 2018

The characteristics of a three-phase synchronous permanent magnet planar motor (SPMPM) are analyzed numerically using a volume integral equation method (VIEM). The mover dimensions are optimized to minimize the detent force. The back-EMF waveform is calculated and the coil dimensions are optimized to set the back-EMF constant to a constant value regardless of mover positions. All simulation results are verified by a comparison with experimental results.
A numerical simulation study for the effect of applied magnetic field in growth of CdTe single crystals by the traveling heater method
Authors: Dost S. , Liu Y. , Lent B. , Redden R.F.
Published: December 2018

A numerical simulation study was carried out for the growth of CdTe crystals by the Travelling Heater Method to examine the effects of applied stationary and rotating magnetic fields, and also small non-uniformities in the stationary magnetic field. A strong stationary field is applied to suppress the natural convection in the solution zone, and a small but rotating magnetic field is considered for better mixing in the horizontal plane. The spatial distribution of the stationary field is almost uniform before the furnace and the growth system are lowered into the magnet opening. However, the field uniformity may be altered by the presence of the growth system. In order to determine the effect of such field non-uniformities, small magnetic body force components are considered in the model. Results show that higher stationary field levels are better in suppressing convection in the solution, but enhance the compositional non-uniformity in the solution. Small but unintentional non-uniformities in the stationary magnetic field also enhance compositional non-uniformity. A rotating magnetic field, on the other hand, is beneficial for mixing in the horizontal plane, and reduces the compositional non-uniformity in the solution. Mixing is enhanced at higher rotating magnetic field frequencies.
Artificial urethral valve driven by SMA actuators with transcutaneous energy transmission system
Authors: Tanaka Mami , Abe Kazuhiro , Wang Feng , Nakagawa Haruo , Arai Yoichi , Tanahashi Yoshikatsu , Chonan Seiji
Published: December 2018

This paper presents the development of a mechanical SMA urethral valve driven by a portable transcutaneous energy transmission system, which is powered by batteries. Structure of the valve was improved by introducing a bite mechanism in order to prevent the pinch of urethra by the valve. The cycling characteristics and energy transmission efficiency were examined by laboratory tests. Experimental results show that the stable operation can be obtained by introducing a voltage regulating circuit to the energy transmission system and utilizing the sinusoidal oscillation in the energy transmission system can enhance the transmission efficiency. Furthermore, the function of the valve system was tested by the vitro and vivo animal experiments.
Development of a megasonic cleaner for TFT LCD manufacturing
Authors: Kim Hie-Sik , Choi Gi Sang
Published: December 2018

The yield rate in fabrication of TFT LCD's (thin film transistor liquid crystal display) with high pixel density is strongly dependent upon the effectiveness of precision cleaning method. Ultrasonic cleaners operating at high frequencies (typically above 1 MHz, megasonic cleaners) are known to be effective in removing submicron contaminants without causing mechanical damage to the surface. In this study a megasonic cleaner for TFT LCD manufacturing process is developed and its performance is evaluated through experiments. The experimental results show that the developed megasonic cleaner is effective in removing very small particles from the LCD panels.
An explicit shortest path generation scheme for point stabilization of the car-like robot in free space
Authors: Doh Nakju , Chung Wan Kyun , Youm Youngil , Oh Sang-Rok
Published: December 2018

This paper proposes a shortest path generation scheme for point stabilization of the car-like robot. An implicit shortest point stabilization algorithm has been suggested conceptually by Vendittelli. As an extension, we present an algorithm which is more explicit and faster than previous one. Our scheme provides exact equations for practical implementation. Moreover, its computation time is remarkably lower than the previous one for the case in which the final point changes frequently. We provide a proof of the optimality and validate the performance of our algorithm through the simulation and experiment.
Design of a remote lighting control system using time division multiplex transmission
Authors: Jung Sung-Jae , Yun Sung-Yong , Kim Il-Hwan
Published: December 2018

In this paper, a new distributive lighting control system for BA(Building Automation) is presented. For optimal lighting control and saving energy in buildings such as hotels, schools and offices, the group and pattern lighting control as well as individual lighting control at one time are required. All the modulated lighting control terminals are connected to the central control unit through a pair of power lines. These power lines provide both power and signals to the each distributed terminal, and data are transmitted using the cyclic time division multiplex transmission algorithm. With this algorithm, a low-cost distributive control system for lighting applications has been achieved, allowing energy and maintenance saving and increasing the reliability of the lighting control system.
A study on the channel equalizer noise of softmodem with Haar transform and neural network
Authors: Lee Seok Won , Nam Boo Hee
Published: December 2018

In this paper, we propose a new structure for a binary data transmission using the neural network and Haar transform to reduce the noise and distortion in the channel. To solve the problems such as signal distortion and nonlinearity during the transmission and reception of the signal, we use the neural network to design an equalizer to adapt the change of the channel characteristics. Before transmitting digital information, two adjacent binary signals are Haar transformed and are sent to the channel which is assumed to corrupt the signal by an additive white Gaussian noise (AWGN), and then we receive the noise-reduced signal through the inverse Haar transform. We analyze the probability of error and simulate the model to show the validity.
Real-time algorithms for estimating jerk signals from noisy acceleration data
Authors: Nakazawa Shin-ichi , Ishihara Tadashi , Inooka Hikaru
Published: December 2018

The time derivative of acceleration, sometimes called a jerk, plays an important role in vibration control, ride comfort evaluation and so on. It is usually required to estimate a jerk from a noisy acceleration signal. Simple numerical differentiation of a filtered acceleration signal often fails to give satisfactory result. A model-based estimation technique is proposed in this paper. Behavior of a jerk signal is modeled by a random walk process. Then the problem of estimating the jerk is formulated as a state estimation problem. On the assumption that the observation noise has a colored noise component, a Kalman filter and an filter are derived for estimating the jerk. The performances of both estimators are compared by simulation. Although both filters provide comparable performances for ideal case, the filter with appropriate use of a priori information has better robustness than the Kalman filter and is more useful in real applications.
Mathematical modeling of the magnetic filtration processes
Authors: Köksal M. , Abbasov T. , Herdem S.
Published: December 2018

A mathematical model is proposed for the determination of non-stationary characteristics of the cleaning process of industrial liquids in magnetic filters. The theoretical investigation which provides the determination of the variation of the captured particles both with time and along the filter matrix is based on the general filtration equations. Considering the properties of the magnetic filtration process, non-stationary filtration equations involve the capturing and detachment coefficients of the particles in the filter matrix. The effect of the filter length on the magnetic filter performance is also presented. The obtained expressions make possible to compare the experimental and the expected theoretical results.
Ferrofluid lubrication of a porous slider bearing with a convex pad surface considering slip velocity
Authors: Shah Rajesh C. , Bhat M.V.
Published: December 2018

Ferrofluid lubrication of a bearing with slider having a convex pad surface and stator having a porous facing of uniform thickness was examined using Jenkins flow behaviour and considering slip velocity at the interface of porous matrix and film region. Expressions were obtained for film pressure, load capacity, friction on the slider, coefficient of friction and the position of the centre of pressure. The load capacity, friction and the position of the centre of pressure decreased when the slip parameter increased. On the other hand, the load capacity decreased and friction as well as the coefficient of friction increased when the material parameter of the Jenkins model increased. No significant change in the co-efficient of friction was found when the slip parameter increased. The position of the centre of pressure shifted towards the inlet when the material parameter increased.
Internal crack in a piezoelectric layer sandwiched between two elastic layers
Authors: Li Xian Fang , Tang Guo Jin
Published: December 2018

The electroelastic analysis of a cracked transversely isotropic piezoelectric layer sandwiched between two elastic layers is made under electromechanical loading. The crack is assumed to be situated at the mid-plane of the piezoelectric layer and penetrate through the piezoelectric layer along the poling direction. By using an integral transform technique, the problem is reduced to dual integral equations. Further a singular integral equation with Cauchy kernel of the first kind is derived and solved numerically by the Lobatto-Chebyshev collocation technique. The field intensity factors and the energy release rate are obtained and the results indicate that they are independent of electric loading for the case of prescribed stress, and depend on electric loading for the case of prescribed displacement on the top and bottom surfaces. The electric field has no any singularity near the crack tips, while the electric displacement exhibits the same singularity as the stress near the crack tips. Some numerical results are presented graphically to show the influence of layer thickness-to-crack length ratio and the material properties on the normalized energy release rate.
Source space localization technique for Magnetoencephalography(MEG) source reconstruction
Authors: Im Chang Hwan , Jung Hyun Kyo , Lee Yong Ho , Kwon Hyuk Chan
Published: December 2018

Magnetoencephalography (MEG) source reconstruction problems suffer from their own ill-posed characteristics, especially when a cortically distributed source model is used. This is because many variables have to be determined using small amounts of measured data, and this leads to a large computational cost. In this paper, a very efficient method is proposed to localize the source space effectively. A Fourier based 3-dimensional spatial function approximates the spatial distribution of the current dipole moments. The coefficients of the function are determined using the sensitivity analysis employing the steepest decent updating scheme. By repeatedly applying the method to smaller and smaller domains, a reduced source space, which includes the small number of variables, can be obtained. By applying this method to a real brain model, its usefulness was verified.
Ferromagnetic shape memory alloys Ni_{2 ± x± y}Mn_{1 ± x}Ga_{1± y}
Authors: Vasil'ev A. , Takagi T.
Published: December 2018

Magnetically driven shape memory alloys, among them Ni _{2± x ± y} Mn _{1 ± x} Ga _{1 ± y} , represent a novel type of material which allow magnetic fields to influence their shape and dimensions in a martensitic state. The basic approach to employ the intelligent properties of these compounds is associated with the rearrangement of martensitic variants by the magnetic field. To realize this possibility, the magnetic anisotropy of the martensitic phase should be large enough to overcome the potential barriers for the motion of the martensite domain boundaries. Huge strains at room temperatures were reported under the competing stress of about 1∼MPa and a magnetic field of about 1 T.
Three-dimensional constrained optimization of modular toroid-type SMES using co-evolutionary algorithm
Authors: Im Chang-Hwan , Jung Hyun-Kyo , Kim Ji-Hoon , Hahn Song-Yop , Hahn Sung-Chin
Published: December 2018

In this paper, a modular toroid-type SMES was optimized using a recently developed constrained optimization technique named co-evolutionary augmented Lagrangian method (CEALM). The objective of the optimization was to minimize the total length of HTS superconductor satisfying some equality and inequality constraints. The constraints were calculated using 3-D magnetic field analysis techniques and an automatic tetrahedral mesh generator. Optimized results were verified by 3D finite element method (FEM).
Defect detection in thick aircraft lap-joint dtructures using HTS SQUID NDE
Authors: Allweins Kai , Gierelt Gertrud , von Kreutzbruck Marc
Published: December 2018

The choice of the NDT industry for an appropriate NDT method focuses on an optimum balance between quality control and cost effectiveness. For this reason SQUID technology, because of its higher costs and handling inconvenience, might be used only where standard NDE techniques fail to ensure sufficiently high reliability. A promising SQUID NDE application is testing of very thick aircraft lap-joint structures, where currently no standard testing method achieves satisfactory results. We present SQUID measurements of a three-layer aluminum sample of the Airbus A-380 with a total thickness of 62 mm, which resembles the planned outer wing splice of the megaliner. The combination of field sensitivities of a few pT/√Hz and a large dynamic range of about 140 dB/√Hz enables us to detect defects at a depth ranging between 30–45 mm.
New realization and microwave properties of double negative material
Authors: Kraftmakher Galina
Published: December 2018

Novel composite medium with simultaneously negative permeability and permittivity at microwave range is presented. The medium contains cutoff waveguide structures and chiral or chiro-ferrite inclusions. Microwave response of such medium is investigated under chiral and chiro-ferromagnetic resonances.
Solution of elliptic inverse problems using the Poincaré-Steklov operator
Authors: Kharytonov A.A.
Published: December 2018

We consider some inverse boundary problems which are to determine the coefficients or functions of elliptic differential equations inside the domain Ω from a knowledge of boundary conditions (the Cauchy data) on ∂Ω. An algorithm for the numerical solution of such problems is presented. The iterative methods and the theory of the Poincaré-Steklov operator are the basis of our consideration. This algorithm can be used for the solution of the inverse conductivity problem and for the determination of the potential in the Schrödinger equation.
Analytical model of a shielded U-core sensor
Authors: Le Bihan Yann
Published: December 2018

In this paper, a simple analytical model of an eddy current sensor having an U-shaped magnetic core and a conductive shielding is presented. Results obtained with the developed model are then compared with data issued from measurements and show a fair agreement. The main advantage of this analytical model lies in its simplicity of implementation and in its high execution speed comparatively to numerical models.
An emigration genetic algorithm for vector optimizations of electromagnetic devices
Authors: Wang Yuhuai , Yang Shiyou , Ni Guangzheng , Ni Peihong , Ho S.L.
Published: December 2018

Based on the success in the design of an Emigration Operator and the introduction of other approaches such as the fitness sharing, the clustering method, and the elitism strategy, an Emigration Genetic Algorithm is now proposed for the vector optimizations of electromagnetic devices. Numerical results are reported to demonstrate the effectiveness of the proposed algorithm in solving engineering multiobjective optimal design problems.
Finite element simulation of magneto inductive evaluation of PWHT temperature of Cr-Mo steel welded joints
Authors: Cheng Weiying , Shiwa Mitsuharu , Chen Gangzhu , Yoneyama Hiroshi , Horii Yukihiko
Published: December 2018

Post Weld Heat Treatment (PWHT) temperature can be evaluated by magneto inductive method. The mechanism of the bulk magnetic property change is explained in terms of Jiles-Atherton hysteresis model. A finite element simulation is implemented for the PWHT temperature evaluation. Comparison between simulation and experimental observation is made and factors influencing simulation are discussed in the present paper.
Development of a polygon scanner motor using single-axis controlled repulsive type magnetic bearing system
Authors: Ohji Takahisa , Ikeno Shigeyuki , Amei Kenji , Sakui Masaaki , Yamada Sotoshi
Published: December 2018

This paper reports on the configuration and performance characteristics of a repulsive type magnetic bearing system, which contains a vertical shaft type inner rotor with polygon mirror facets. Generally, low cost, high-speed rotation, power saving and rotational accuracy are important factors for the polygon mirror system. The experimental model introduced in this paper has achieved the stable rotation without contact at 50,000 rpm and low power consumption for a motor drive under low vacuum condition.
Transformation behavior of Fe-Cr-Co-Ni-Si-Mn ferromagnetic shape memory ribbon
Authors: Todaka Takashi , Szpryngacz Mariusz , Enokizono Masato
Published: December 2018

A new ferromagnetic shape memory alloy consisting of Fe-Cr-Co-Ni-Si-Mn has been developed by means of the melt spinning technique. The alloy has both the shape memory effect and the comparatively high-magnetic permeability itself. The shape memory effect can be improved with annealing the alloy, however at the same time it loses good ferromagnetic properties. This paper presents the measured magnetic properties and shape memory characteristics measured by the vibration sample magnetometer (VSM), the differential scanning calorimeter (DSC) and the thermo-mechanical analyser(TMA).
Data representation by field calculus and leading to the orthonormal linear transforms
Authors: Endo Hisashi , Takasuka Yoshihiro , Marinova Iliana , Hayano Seiji , Saito Yoshifuru
Published: December 2018

This paper proposes a method of data set representation by potential field equations. The principal idea of the representation is to regard a numerical data set as a kind of potential/source fields, leading to the governing equations. The modal analysis of the equations derives the orthonormal linear transform matrix. It is described that the matrix corresponds to that of discrete wavelets performing an efficient wavelet multi-resolution analysis.
Uncertainties associated with current measurements: Analysis by the finite element method
Authors: Letosa J. , Usón A. , Artal J.S. , Samplón M. , Arcega F.J.
Published: December 2018

The paper analyses the effect of crosstalk magnetic fields in current measurement devices with magnetic cores, as clamp-type current meters and current transformers. FEM modelization was used to calculate relative errors due to the crosstalk currents and how these errors are affected by variables as permeability, non-linearities and distance. Experimental results are also reported, in order to validate the numerical calculations. The measurements were obtained using the resources of the LME (Electric Metrology Laboratory) of the Electrical Engineering Department of the University of Zaragoza, accredited by ENAC, a member of EA (European Co-operation for Accreditation).
Conformal FIT formulation for simulations of electro-quasistatic fields
Authors: Schreiber Ute , Clemens Markus , van Rienen Ursula
Published: December 2018

The Finite Integration Technique (FIT) is a discretization scheme for Maxwell's equations, where commonly orthogonal tensor product grids are preferred for efficiency reasons. However, orthogonal grids have difficulties to model curved shape boundaries. For the simulation of electro-quasistatic(EQS) fields with the Finite Integration Technique (FIT) a new technique is introduced, which allows an improved geometric modeling of curved boundaries while maintaining orthogonal tensor product grids. The reduction of the geometrical errror results in the improvement of the solution accuracy. Numerical results for a test problem show the improvement in accuracy with the new approach.
Simulation and experimental validation of induction machine dynamics driving multi-inertial loads
Authors: O'Sullivan T.M. , Schofield N. , Bingham C.M.
Published: December 2018

Dynamic models of electrical machines and their associated drive-train mechanics have had limited experimental validation to-date, due, primarily, to the difficulty in the dynamic measurement of torque. This paper presents results from a study investigating the feasibility of utilising a novel, non-contact, torque measurement system, based on surface acoustic wave(SAW) technology, for application in brushless machine-based, servo drive systems. Simulation of the drive system is facilitated via the implementation of a linear d-q axis induction machine model, coupled with a multi-mass model of the driven mechanical system. Experimental validation of the simulation models is augmented via a test facility comprising of a direct-on-line (DOL) squirrel cage induction machine coupled to an induction generator which provides an electromagnetic and inertial load. The results presented show a good correlation between simulation models and experimental test data previously not acheivable prior to the SAW technology due to the absence of a torque measuring system having suitable bandwidth.