bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanics performance test of MR damper and its application in structural seismic response control
Authors: Sun Qing , Wu Xiaohong , Xue Xiaomin , Zhang Lei , Zhang Ling
Published: December 2018

Magnetorheological (MR) dampers are new semi-active control devices in which the damping forces are controlled by magnetic field. In this study, the performance of a semi-active control system based on newly developed MR fluid damper is researched. A simple parallel plate model is used to investigate the MR damper's behavior. The comparison between the analytical and experimental results verifies the theoretical analysis. A Three-Degree-of-Freedom (3DOF) lumped-parameter model is introduced to represent a model-scale civil structure installed with the damper. Semi-active control method such as Continuous Sliding Mode (CSM) controller is simulated. Excellent results are obtained when this strategy is applied. The results demonstrate that the MR damper has the potential for improving the seismic behavior of civil structures.
Effects of time delay on resonance of a nonlinear magnetic bearing system with delayed feedback
Authors: Zheng Kai , Yu Lie
Published: December 2018

This paper investigates the dynamic behaviour of a typical rotor-active magnetic bearings (AMBs) system with delayed feedback. The method of multiple scales is used to obtain the averaged equations in the case of primary resonance and 1/3 subharmonic resonance. The effect of short delay in feedback loop of system on the resonances is studied with respect to the steady-state response and stability of the system. Results of the studies show that time delay not only influences the amplitude and phase of primary resonance and 1/3 subharmonic resonances, as well as resonance region, but also has a significant effect on threshold of excitation amplitude that can induce 1/3 subharmonic resonance.
A new two-parameter multi-axial fatigue failure criterion based on shear and normal strains
Authors: Ba Ying , Zhang Li , Cheng Jin
Published: December 2018

A new simple two-parameter multi-axial fatigue failure criterion is proposed, which is focused on the engineering application. The proposed multi-axial fatigue failure criterion is based on shear strain and normal strain, and then focused on cycling additional hardening normal stress is selected to replace normal strain. The damage degree is assumed to be linearly accumulated. The larger one of the two parameters determined the orientation of critical pane, and the linear combination of the two parameters is considered to be simple and convenient to predict fatigue life.
Magnetic telemanipulation device with mass uncertainty: Modeling, simulation and testing
Authors: Mehrtash Moein , Shameli Ehsan , Khamesee Mir Behrad
Published: December 2018

Recently, magnetic telemanipulation devices have shown a great deal of promise in such areas as semi-conductor manufacturing, wind tunnels, drug delivery, and many more. However, these devices are generally associated with problems caused by payload variation and uncertainties in the parameters of the system which in turn, have limited the development and application of magnetic telemanipulation technology to its full capacity. This paper addresses and deals with these issues by implementation of a precise position control method for a magnetic telemanipulation system with high level of uncertainties in its parameters. The levitation system used in this study is primarily designed for performing remote pick and place operations. The levitated object is a 28 gr microrobot capable of grasping and releasing payloads as heavy as 8 gr. To cope with the uncertainties in the modeling and payload variation, a model reference adaptive feedback linearization (MRAFL) controller is designed and its performance compared with an ordinary feedback linearization (FL) controller. Through experimental results it is shown that the MRAFL controller enables the microrobot to grasp and transport a payload as heavy as 30% of its own weight without a considerable effect on its positioning accuracy. In the presence of the payload, the MRAFL controller resulted in a RMS positioning error of 8 μm} compared with 27.9 μm} of the FL controller. The approach presented in this work is versatile as it leads to the modeling and control of a highly nonlinear system through a modular approach that can be applied to a variety of magnetic levitation and telemanipulation systems.
Design and experiment of multiple piezoelectric bimorphs for scavenging vibration energy
Authors: Shan Xiao-Biao , Yuan Jiang-Bo , Xie Tao , Chen Wei-Shan
Published: December 2018

This paper presents a mathematical model for designing broadband piezoelectric energy harvesters by integrating multiple piezoelectric bimorphs(MPBs) with different resonant frequencies into a system. The finite element method (FEM) was used to predict the resonant frequencies of the MPBs. To verify the theoretical analysis, the resonant frequencies of the MPBs were measured using an experimental method. The results obtained from theoretical analysis were in very good agreement with those from the FEM and experimental results. The performance of MPBs is studied in energy harvesting. The results show that the MPBs can effectively increase the output power and enable broadband energy harvesters.
Temperature effect on electromagnetic forming process by finite element analysis
Authors: Kuo Chia-Lung , You Jr-Shiang , Hwang Shun-Fa
Published: December 2018

In the electromagnetic forming (EMF) process, the Lorentz force is generated by the repulsive interaction of magnetic field between a pulse transient current in a coil and an eddy current in a workpiece. During the process, the current will generate Joule heat in both the coil and workpiece raising their temperatures. The objective of this work is to build a coupled analysis to consider the temperature effect during the electromagnetic sheet metal forming process by using a finite element analysis. During the analysis, the electromagnetic, mechanical and temperature problems are considered simultaneously. Then, the coupling effects of the temperature with eddy currents, magnetic fields, magnetic force density, and deflection of the sheet metal are discussed. The results indicate that the temperature increasing is significant especially during repeated working cycles, and the deflection of a sheet metal is reduced as the increasing of the coil temperature. Hence, this temperature effect should be considered to avoid the failing of products and to improve the life of the forming coil, especially in a mass production process.
Microwave effective medium theory for two-component magnetic metamaterials
Authors: Rybin Oleg
Published: December 2018

In this paper, Effective Medium Theory for two-component metamaterial media as infinite host dielectric medium embedded periodically with cylindrical iron inclusions and spherical ones saturated with an external biasing magnetic field is developed in the microwave frequencies. The long wave approximation of effective permeability tensors for the considered metamaterial media has been obtained using the microwave extension of Effective Medium Approximation for polycrystalline ferrites and the long wave approximation of expressions of the effective magnetic permeability for two-component undiluted metal-dielectric composites with infinitely long non-magnetic metal cylindrical and spherical inclusions. The effective magnetic properties of the metamaterial media for the case of microwave propagation transverse to bias have been studied. It is shown that the considered metamaterial can exhibit the ultra-low refractive index phenomenon and the phenomenon of negative magnetic permeability for the case of microwave propagation transverse to bias.

An erratum to this article can be found in [International Journal of Applied Electromagnetics and Mechanics 35(4), 2011, 307], http://iospress.metapress.com/content/v5q6821720352105/fulltext.pdf
Development of a magnetic sensor system for predictive IASCC diagnosis on stainless steels in a nuclear reactor
Authors: Nemoto Yoshiyuki , Keyakida Satoshi , Uchimoto Tetsuya , Takaya Shigeru , Tsukada Takashi
Published: December 2018

The authors previously reported that magnetic flux leakage data, measured using a flux gate (FG) sensor, showed a correlation with the irradiation-assisted stress corrosion cracking (IASCC) susceptibility of neutron-irradiated austenitic stainless alloys. This paper presents a study conducted to develop a diagnostic system that can detect IASCC precursors in stainless steels by measuring the magnetic properties of the material. The eddy current method and alternating current (AC) magnetization method were used, as these will be more practical for use in actual reactors. Probes were developed for these measurement methods, providing sufficient tolerance for environments in nuclear reactors. An attempt was also made to improve spatial resolution by manufacturing a smaller probe. A sensor system was designed for remote control, performance tests were conducted by measuring neutron-irradiated specimens and mock specimens, and magnetic data were evaluated by comparing the IASCC susceptibility of the specimens. It was proved that the sensor system developed in this study is capable of detecting IASCC precursors. Further developments necessary for application in actual nuclear reactors and the mechanism of correlation between magnetic properties and IASCC susceptibility were also discussed.
Robot manipulator control using EMG generated from a face
Authors: Sagawa Koichi , Kimura Orie
Published: December 2018

A robot manipulator control method using an electromyogram (EMG) from a human face is proposed. The robot has a three-degree-of-freedom arm with an end effector installed on the tip of the robot. The amplitude of the EMG signal generated from the masseter, a jaw muscle, is used to control the robot hand velocity and to grasp the object. The difference of the EMG level between right and left masseter determines the hand's direction of movement. The open-close control of the robot hand is activated by detecting double clenches performed within 0.6 s. Low-pass filters of two kinds are applied to the measured EMG to enable reliable and effortless control of the velocity and grasping task. Picking, transferring, and placing of a brick object are performed. The effectiveness of the proposed method was verified.
Thin layer electrohydrodynamic (EHD) drying and mathematical modeling of fish
Authors: Bai Yaxiang , LI Xinjun , Sun Yang , Shi Hu
Published: December 2018

The main objective pursued in this paper is to investigate the single layer drying behavior of fish slices experimentally in an electrohydrodynamic (EHD) dryer and also to perform mathematical modeling. Drying experiments of fish slices were studied at 10, 15, 20, 25 and 30°C, relative humidity of 30%, 40%, 50%, 60% and 70%, drying voltage from 5 kV to a maximum voltage of 50 kV in increments of 5 kV, the moisture content of fish slice for constant sample thickness (8 mm), and the samples thicknesses from 2 mm to a maximum 16 mm in increments of 2 mm in a EHD dryer. Sample weight, drying rate were measured during drying and drying rate curves were obtained for each experimental data. The drying rate data were performed using seven different mathematical models to estimate a suitable model according to their correlation coefficient (R), determination coefficient (R ^{2} ) and standard error (S), which were predicted by linear and non-linear regression analysis using SPSS computer program. It was deduced that the quadratic model were found to satisfactorily describe the drying rate of fish with the drying voltage, ambient temperature and drying time, respectively. However, the exponential model was the most suitable model to describe the drying rate of fish with the relative humidity, the moisture content and the thickness of fish slices, respectively.
Compact, low return-loss, and sharp-rejection UWB filter using Sierpinski carpet slot in a metamaterial transmission line
Authors: Xu He-Xiu , Wang Guang-Ming , Yang Xiao-Lei , Chen Xin
Published: December 2018

In this paper, a novel ultra-wide band (UWB) bandpass filter (BPF) and its equivalent circuit model are presented by etching a Sierpinski carpet slot on a single negative metamaterial (MTM) transmission line (TL). The MTM TL, demonstrated with negative permeability within two bands, consists of a Koch slot etched in the ground plane and a series capacitive gap etched in the upper stepped-impedance conductor line. The BPF is investigated in depth using full-wave electromagnetic (EM) simulation, electrical simulation and extracted constitutive EM parameters. Different geometrical elements on the overall performance of the filter are also systematically studied. A set of design guidelines and a simple method to extract lumped-element parameters are derived, which are of a practical value in future design. For verification, the developed BPF is fabricated and measured. Consistent results between simulation and measurement have confirmed the design, showing that the BPF with a relative bandwidth of 140.3% offers many advantages such as compact size, comparable low return loss and insertion loss, sharp and deep out-of-band rejection, and small variation in group delay.
Using anisotropic dielectrics to improve frequency selective surfaces response
Authors: Pereira de Siqueira Campos Antonio Luiz
Published: December 2018

This paper describes the use of anisotropic substrates to improve Frequency Selective Surfaces (FSS) response. Initially, we present the entire formulation to analysis of FSS on anisotropic dielectric substrates. After this, we present numerical and experimental results to point out that the use of anisotropic substrates can improve the FSS response. Those results are compared with isotropic substrates for the same structures. Finally, conclusions are listened.
Calculation of magnetic levitation force exerted on the cylindrical magnets immersed in ferrofluid
Authors: Yang Wenming , Li Decai , He Xinzhi , Li Qiang
Published: December 2018

The magnetic levitation force exerted on the magnets immersed in ferrofluid is the theoretical basis of various application of ferrofluid. In this paper, based on the equivalent magnetic charge models and the equivalent current models of cylindrical magnets, magnetic charge image method and current image method are used to calculate the magnetic levitation force exerted on the cylindrical magnets immersed in ferrofluid respectively. The magnetic levitation force under the same conditions is calculated by the Comsol Multiphysics software according to the mechanical formula after the distribution of the magnetic field is obtained using finite element method. The magnetic levitation force is also measured experimentally, whose results are compared with the theoretical results obtained by the three methods. The analysis shows that the variation law of the magnetic levitation force and the influence by various parameters can be evaluated by the calculation with magnetic charge image method and current image method, but there is great difference between the theoretical results and the experimental results, and the greatest difference are 46% and 62% respectively. The agreement between the theoretical and the experimental results is quite good when the finite element method is used, whose greatest difference is 9%.
Electromagnetic transient studies in the ITER tokamak
Authors: Albanese Raffaele , Bellesia Boris , Palmaccio Roberto , Portone Alfredo , Mateos Felix Rodriguez , Rubinacci Guglielmo , Tamburrino Antonello , Testoni Pietro , Ventre Salvatore , Villone Fabio
Published: December 2018

The ITER tokamak is a very complex electromagnetic system that requires a careful assessment for for assuring its reliable operation as well as its mechanical integrity. In this paper we discuss the effects of the fast electromagnetic transients on the superconducting magnet system. Of particular complexity is the analysis of the quench detection system of the TF coils that can be improperly triggered by the spurious signals due to the inductive coupling with the plasma and the other active and passive magnetic field sources.
On the measurement of plasma power in atmospheric pressure DBD plasma reactors
Authors: Hołub Marcin
Published: December 2018

Proposed paper deals with the subject of plasma power measurement in dielectric barrier discharge (DBD) reactors. Four approaches are compared including analytical, electrical, Lissajous figure and comparative methods. Discussion is led regarding measurement sensors, digital oscilloscope time base resolution and measurement capacitor technology. Lissajous curve approach gives results that are very comparable to definition based power calculation. Analytical approach, due to technical reasons, is inadequate, comparative approach gives slightly elevated values with respect to other methods. Measurement capacitor value should be of comparable capacitance to reactors overall capacitance, a pulsed technology capacitor should be used for measurements.
Locating and identifying ferromagnetic objects
Authors: Wołszyn Mirosław
Published: December 2018

The new non-iterative method of determining the dipole moment and location is presented in this paper. The algorithm of an object's localization and identification was achieved by using numerical calculations and approximation method. The arbitrary shapes of an object were assumed in the identification algorithm – axially symmetric spheroid (a prolate and an oblate). Several examples of localization and identification of an object's models were presented. Magnetic field of each object's model was calculated in Opera 3D program. An example of determining a missile's location and identification was presented in this paper.
Multidipoles model of ship's magnetic field
Authors: Jakubiuk Kazimierz , Zimny Paweł , Wołszyn Mirosłw
Published: December 2018

Ships made of ferromagnetic metals interfere with Earth's magnetic field in their surrounding. The disturbance of the magnetic field makes possible localization and even identification of the ship, which could determine a threat to the ship. The measurement of the magnetic field around the ship enables to determine its magnetic signature. The paper presents a multidipoles model of the ship magnetic field, which allows to determine parameters of the ship magnetic signature.
Modelling eddy current testing of ferromagnetic medium
Authors: Zorni Chiara , Reboud Christophe , Decitre Jean-Marc , Santandréa Laurent , Bihan Yann Le , Ventre Salvatore , Tamburrino Antonello , Lambert Marc
Published: December 2018

Three numerical approaches ((i) a semi-analytical model based on a volume integral method; (ii) an integral formulation solved in terms of a finite-element approximation; (iii) a finite-element solver using complementary magnetic and electrical formulations) modelling the response of a probe to the presence of a defect affecting a planar-stratified ferromagnetic material are presented and their results compared with one another and with experimental or numerical results of literature.
Design and fabrication of a microactuator for a hearing aid
Authors: Creutzburg Tom , Rissing Lutz , Lenarz Thomas , Reuter Günter
Published: December 2018

In order to design an electromagnetically driven microsystem serving as an ear implant to overcome amblyacousia, Finite Element Method (FEM) simulations were conducted. The system consists of three parts, an upper system part, a lower system part and a plunger. The design process included mechanical, electromagnetic, and thermal simulations. Based on the simulations a system layout was derived and the microactuator was fabricated on the basis of micro system technology processes in batch fabrication. The assembly of the system was performed on system level.
Influence of the component size ratio on densification and magnetic property of soft magnetic composites
Authors: Xiao Ling , Ding Chunhua , Sun Yanhua , Yang Lihua , Yu Lie
Published: December 2018

To analyze the influence of the component size ratio(matrix/inclusion) on the densification and magnetic property, the equivalent model of SMCs at particle scale was used for static case. The relation of porosity, density against the component size ratio δ is deduced. To calculate the effective permeability of the model, the equivalent magnetic circuit method and magnetic energy method are proposed and compared. The results show that the densification and effective permeability are dependent on the component size ratio. The effect of porosity is even more pronounced for the effective permeability. In addition, the results of this model are consistent with the experimental results.
The dynamic behaviour of magnetic levitating magnet-magnetic fluid element in alternating magnetic field
Authors: Sudo Seiichi , Goto Takumi , Shinozaki Michihiro , Kainuma Toshiya , Takana Hidemasa , Nishiyama Hideya
Published: December 2018

Experimental study on the dynamic behaviour of magnetic levitating magnet-magnetic fluid element in the external alternating magnetic field is described. Two types of element motions occur according to the magnetic field strength and frequency of the external alternating magnetic field. Seesaw motions of the element and harmonic motions of magnetic fluid surface are observed using high-speed video camera system. Transient phenomena in element response and the change of spikes pattern on the magnetic fluid surface are revealed.
An experimental study of power generation and storage using a flexible piezoelectric device
Authors: Tanaka Yoshikazu , Matsumura Keitaro , Mutsuda Hidemi
Published: December 2018

An experimental study of a small, efficient and flexible piezoelectric power generator is presented herein. Forced vibration experiments were performed and the results show linearity between amplitude of output voltage and maximum vibration velocity. Experiments for storage of the power generated were also performed. These confirmed that the power can be stored in capacitors with the time derivative of the stored energy being independent of the capacitance value.
Effectiveness of using a magnetic compound fluid with a pulsed magnetic field for flat surface polishing
Authors: Nishida Hitoshi , Shimada Kunio , Ido Yasushi
Published: December 2018

The effects of the frequency of a pulsed magnetic field on flat polishing were investigated to obtain basic data for increasing the performance and precision of polishing using MCFs. We clarified that the profile curves after polishing differ for a direct-current magnetic field and for a pulsed magnetic field and flattening occurred over a wide range when the frequency of a pulsed magnetic field is 0.1 Hz.
A novel technique based on integral formulation to treat the motion in the analysis of electric machinery
Authors: Calvano F. , Dal Mut G. , Ferraioli F. , Formisano A. , Marignetti F. , Martone R. , Rubinacci G. , Tamburrino A. , Ventre S.
Published: December 2018

A critical aspect of the 3D electromechanical analysis of rotating machinery is the treatment of motion. The paper proposes a technique taking advantage of the numerical characteristics of integral formulations. The motion can be "naturally" modelled because no mesh in the free space and, consequently, in the air gap is required. A frequency domain procedure is presented. It exploits a fixed point iteration technique to deal with magnetic nonlinearities. The procedure is able to determine a periodic steady state solution of a magneto quasi-static problem with both motional and trasformatoric effects. In order to highlight the effectiveness and the general validity of the approach, some numerical examples are presented, including the calculation of 3D Lorentz force density waveforms in massive non magnetic regions of a large turbine generator.
Accurate design of Helmholtz coils for ELF Bioelectromagnetic interaction by means of Continuous FSO
Authors: Coco Salvatore , Laudani Antonino , Fulginei Francesco Riganti , Salvini Alessandro
Published: December 2018

A new Continuous Flock-of-Starling Optimization (CFSO) procedure is presented for the solution of the inverse problem regarding the accurate design of the Helmholtz coils, usually used for the exposure of biological samples to ELF magnetic field. The CFSO is the continuous equivalent model of the FSO algorithm, and it is expressed in terms of a state space representation. The trajectories of the CFSO particles are obtained as solutions of a differential equations system within suitable Time-Windows (TWs). Starting from any initial state, thanks to this "continuous" representation, it is increasingly possible to refine the solution by reducing the amplitude of the TWs at any time, during the optimization procedure. Validation results are presented.
Collision energy analysis of miniature electromagnetic relay with permanent magnet
Authors: Yamaguchi Tadashi , Kawase Yoshihiro , Suzuki Satoshi , Koyanagi Wataru , Hirata Katsuhiro , Ota Tomohiro
Published: December 2018

Recently, miniature electromagnetic relays are required to have high reliability. The reliability of the relay is lost by numerous collisions of a contact. Therefore, we calculate the collision energy of a miniature electromagnetic relay with a permanent magnet through the dynamic characteristics analysis using the three-dimensional finite element method (3-D FEM). The effects of the material of the armature and the number of coil turns on the collision energy are numerically clarified.
Pareto optimization of antennas for passive UHF-band RFID
Authors: Watanabe Yuta , Watanabe Kota , Igarashi Hajime
Published: December 2018

This paper presents multi-objective optimization of meander line antennas (MLA) for passive UHF-band Radio Frequency Identification. The characteristics of the MLA loaded by Cockcroft-Walton (CW) circuit are analyzed by hybrid analysis of the finite difference time domain method and modified nodal analysis. The antenna shape is optimized in order to maximize the output voltage of the CW circuit and minimize the antenna size.
Design and comparative analysis of single and multi-stack axial flux permanent magnet synchronous generator
Authors: Syed Qurban Ali Shah , You Yong-min , Kwon Byung-il
Published: December 2018

This paper attempts to design a direct driven axial flux permanent magnet synchronous generator (AFPMSG) with better accuracy considering magnetic flux leakages and fringing effect, using D ^{2} L method. Design results of conventional and improved design processes are analyzed and compared using 3D finite element method (FEM). Single and multi-stack AFPMSG topologies are designed by using an improved design process. FEM structural analysis is utilized to improve power to weight ratio of three-stack AFPMSG. Finally characteristics of both single and three-stack AFPMSG topologies are analyzed and compared using 3D FEM analysis.
Production of magnetic planetary gear and measurement of basic properties
Authors: Ando Yoshinori , Ugajin Takatoshi , Baba Akira , Fujita Tomoyuki , Nagaya Kousuke
Published: December 2018

A non-contact gear mechanism is important for the non-contact transmission of a torque and a motion. In this paper, a magnetic gear system without contact which requires no lubricant oil is proposed. The driving gear consists of some iron discs with gear teeth whose shape is an involute curve. The discs of the follower gear are inserted in the gaps between the discs of the driving gear, and the attractive forces between the discs generate the torque transmission. Using the magnetic gear system, a magnetically connected planetary gear device is developed. Moreover we measure and study the slip torque as static property, and the step-out torque as dynamic property due to implication of rotational speed.
Tactile-based object manipulation (TbOM) for a multi-fingered robot hand
Authors: Fukui Wataru , Kobayashi Futoshi , Kojima Fumio , Nakamoto Hiroyuki , Maeda Tadashi , Imamura Nobuaki , Sasabe Kazuhiro , Shirasawa Hidenori
Published: December 2018

Although a number of multi-fingered robot hands have been developed, none of these hands is in actual use. One reason for this is that conventional control methods are not useful for multi-fingered robot hands. A human manipulates an object using tactile information (contact points, direction, and severity of reaction force). In the present paper, a tactile-based control method for multi-fingered robot hands, which mimics human manipulation, is proposed. In the proposed method, three fingers are used for object manipulation, and object grasping and manipulation is achieved. The proposed method is implemented in Universal Robot Hand II, and its effectiveness is verified.
Analysis of skewed angle effects of rotor in switched reluctance motor on electromagnetic parameters using FEM
Authors: Zhang Jingjun , Zhang Haijun , Ding Guangbin , Gao Ruizhen , Long Rong
Published: December 2018

It is known that skewed rotor structure for electrical machines can reduce torque ripple and radial force which will produce the unwanted vibration and noise, however, utilizing this structure can also affect other parameters of machine such as the average torque, the inductance, the flux-linkage and the magnetic energy and so on. This drawback always shows in the special and popular machines-switched reluctance motors. In this paper, different skewed angles of rotor and their effects on the key electromagnetic parameters are analyzed for switched reluctance motor. During the whole analysis process, three-dimensional finite element method is used to model, mesh, solve, and plot the results. Especially, the properties of the magnetic materials, the complex motor geometry, the effects of magnetic saturation and end windings were considered. Simulated and compared results show that an appropriate skewed angle selected can reduce the radial force largely but not make the average torque decreasing badly, which can be observed from the final conclusion: under the skewed angle of 5°, the radial force is reduced of 56.2%, the average torque is only reduced of 18.9%. So, if the target of designing for switched reluctance motors is to reduce the vibration and noise to be the most extent, then selecting an appropriate skewed structure for rotor shape is an effective way.
The numeric calculation for cylindrical magnet's magnetic flux intensity
Authors: Yang Wan'an , Zhou Gang , Gong Kai , Li Yan
Published: December 2018

Based on the theory of molecular current hypothesis, the model of the magnetic flux intensity at a point around the cylindrical magnet is established, and a numeric method for the solution of the model is proposed. Compared with the dipole model, this method doesn't need the precondition that the distance from the magnet to the evaluation point is much larger than the maximum dimension of the magnet. At the same time, a group of the parametric values and experiment results are illustrated.
Characterisation of electromagetic welding equipment
Authors: Kumar Satendra , Desai and S.V. , Chakravarthy D.P.
Published: December 2018

The paper describes the procedure for selection of electromagnetic parameters which govern the Electromagnetic Welding (EMW) process. EMW is a specific application of electromagnetic Forming (EMF). The metallic bodies get deformed and eventually collide to get welded. Hence it is classified as deformation bond. It is observed that the parameters such as input electrical energy, ringing frequency, coil geometry, coil conductor section, job material and it's configuration play a very important role in achieving the welding. In addition to this, the separation distance between the two colliding bodies(plates in the present case) is also a crucial parameter. These parameters together decide the resultant collision velocity. The collision velocity in turn decides the strength of weld joint. The procedure is formulated based on computational and experimental observations as applied to 1 and 2 mm thick aluminium plates. This procedure could be extended for other materials and their combinations (such as similar or dissimilar and of different dimensions).
Electromagnetic fields in a circular waveguide with D'B'-boundary conditions internally coated with chiral-nihility medium
Authors: Hassan Muhammad Haseeb , Junaid Mughal Muhammad , Farooqi Abdul Razzaq
Published: December 2018

The present study deals with the propagation of electromagnetic fields and power in a circular waveguide, with D'B'-boundary conditions, internally coated with chiral-nihility medium. The electromagnetic fields inside the two layer circular waveguide defined by D'B'-boundary conditions, with one layer containing free space while other layer containing chiral-nihility medium, is investigated. D'B'-boundary conditions require vanishing of derivatives of the normal field components of D and B vectors, hence named as D'B'-boundary conditions. It has been investigated that unlike to the chiral-nihility coated perfect electromagnetic conductor (PEC) waveguide, there is a non-zero power transfer in chiral-nihility region in waveguide with D'B' boundary conditions.
Numerical simulation and stability analysis on MHD free convective heat and mass transfer unsteady flow through a porous medium in a rotating system with induced magnetic field
Authors: Haque M.M. , Alam M.M. , Ferdows M. , Al-Mdallal Qasem M.
Published: December 2018

A numerical study of Soret and Dufour effects on MHD free convective heat and mass transfer unsteady high speed flow of viscous fluid through a porous medium with induced magnetic field is investigated in a rotating system. In this observation, heat and mass fluxes from the medium are considered to be constant for cooling problem with lighter and heavier particles. Numerical values of velocity, induced magnetic field, temperature and concentration are computed by the conditionally stable explicit finite difference method with stability and convergence analysis. The shear stress, current density, Nusselt number and Sherwood number are also calculated here. Effects of associated parameters on the above mentioned quantities are shown graphically and physical aspects of the problem are discussed in detail. Finally, both the qualitative and quantitative comparisons of present results with previous work are presented in tabular form.
Axially Opposed Magnetization for Free Piston Stirling Engines
Authors: Rogers Uri , Clark David , Jackson Scott , Ferguson Tammy , Harris David
Published: December 2018

A renewed focus on Free Piston Stirling Engines (FPSE) for Green Solar based power generation provides a vehicle to explore linear alternator technologies for improved performance and efficiency. This paper evaluates Axially Opposed Magnetization (AOM) linear alternators and the potential advantages this technology provides mechanically and magnetically relative to alternator efficiency, while also addressing potential disadvantages from a thermal perspective. Evaluations include numerical analysis, simulation, physical testing, and commercial technology comparisons.
Power loss and attenuation in a disc-loaded cylindrical waveguide
Authors: Singh R.K.
Published: December 2018

In the present paper, a disc-loaded circular waveguide structure has been field analyzed for the power loss and attenuation characteristics. The structure has also been simulated with commercially available simulation tool'CST Microwave Studio'. The analytical results have been found in close agreement with the simulation results. Attenuation characteristics have been observed for a disc-loaded circular waveguide interaction structure made of materials of different electrical conductivity and has been observed that the material with higher conductivity results in lower attenuation. Further, the variation of attenuation characteristics has been observed for two different azimuthally symmetric modes typically TE _{01} and TE _{02} . Power loss at different surfaces of the disc-loaded circular waveguide excited in TE _{01} mode has also been observed and it has been found that the tip of the discs is the surface where maximum power loss per unit area occurs. Further, it has been found that with increasing the disc-hole radius the ohmic power loss as well as attenuation constant decreases and with increasing the structure periodicity, the ohmic power loss and attenuation increases. Hence, the structure dimensions should be optimally selected for higher bandwidths and gains.
Response surface modelling of magnetic device performance using function value and gradient
Authors: Dyck Derek N. , Lowther David A.
Published: December 2018

This paper introduces a Response Surface Model (RSM) which is constructed using both the function value and its derivative (or gradient) at the sample points. The model is a version of Interpolating Moving Least Squares (IMLS) which is essentially quadratic interpolation in a multi-dimensional table of scattered sample points. The method is especially cost-effective for response surfaces in many dimensions (on the order of 10 variables). The method is tested on a speaker assembly design problem with seven design variables, and compared to a Multiquadric RSM.
Some results on a SMES device optimization benchmark problem
Authors: Alotto P. , Brandstaetter B. , Fuerntratt G. , Magele Ch. , Molinari G. , Nervi M. , Repetto M. , Richter K.R.
Published: December 2018

The scope of this paper is to throw some light on the difficulties occurring when optimizing in a discrete parameter space. In the first section of this paper some general considerations on the optimization of a SMES device in a discrete space are made. In the second part a pattern search technique as a representative for deterministic, an evolution strategy and a simulated annealing algorithm as members of the class of stochastic methods are presented and used to optimize the problem. The effect of varying the discretization is investigated for the pattern search method. In the next section some features of the benchmark problem are introduced and finally the optimization results are given.
The absorption of electromagnetic waves at microwave frequencies by synthetic chiral and racemic materials
Authors: Cloete J.H. , Kuehl S.A. , Bingle M.
Published: December 2018

Physical principles are discussed which may improve the absorption of electromagnetic waves, especially in the microwave regime, by synthetic chiral and racemic materials. These principles are used to design a chiral composite for enhanced electromagnetic wave absorption at about 14 GHz. The chiral absorber consists of single‐turn copper helices, each wound on a ferrite core and randomly dispersed in a dielectric absorber made of tiny spheres of graphite‐coated expanded polystyrene. Its constitutive parameters, and those of some related dielectric, chiral, non‐chiral (bihelix) and racemic absorbing composites, are studied in the 10 to 18 GHz band. The materials are analyzed as third‐order Dällenbach layers to compare their ability to reduce normal incidence specular reflection by a flat metal plate. The presence of half‐wave resonant helices moderately increases the absorption bandwidth of the dielectric host. A chiral composite and its racemic counterpart have essentially identical properties as absorbers of specular reflection.
Nonlinear optics in anisotropic media
Authors: Arnold J.M. , Hutchings D.C.
Published: December 2018

Nonlinear electromagnetic propagation in materials having anisotropic nonlinear susceptibilities induces complex dynamical phenomena which can be controlled by appropriate engineering of the material. Two optical examples are studied, of second‐harmonic generation and third‐order polarisation instabilities in cubic semiconductors, exemplified by gallium arsenide.
Spatial electromagnetic fields in a nonhomogeneous Omega medium with circular cylindrical symmetry
Authors: Vegni L. , Toscano A.
Published: December 2018

The general theory of the propagation of the electromagnetic field in Omega media with cylindrical symmetry where the density of the Ω-shaped conducting microstructures drops as a function of 1/\rho fed by extended electric cylindrical sources is addressed, and it is established that the wave phenomena can be modeled in terms of the Kummer differential equation. This model leads to closed form analytical expressions in terms of the confluent hypergeometric functions for all the components of the electromagnetic field in far zone.
Reflection of electromagnetic waves from dense arrays of thin long conductive spirals
Authors: Yatsenko V.V. , Tretyakov S.A. , Sochava A.A.
Published: December 2018

Complex three-dimensional grids formed by parallel conductive spirals are considered using a homogenization procedure. Spirals are replaced by straight wires with periodically inserted loops. Averaged electric and magnetic currents are determined which allows to calculate the reflection and transmission coefficients. Numerical examples for co‐ and cross‐polarized reflection and transmission coefficients are given.
Formulations of the coupled mathematical models of microwave heating processes
Authors: Komarov Vyacheslav V.
Published: December 2018

Diverse mathematical models are used nowadays for predicting temperature patterns in dielectric materials exposed with microwaves in domestic ovens, industrial setups, experimental chambers and etc. Most of them are nonlinear and take into account the coupling of electromagnetic and thermal fields in so-called interaction zone. The most frequently utilized coupled models of microwave heating processes are considered in present paper. It is shown that in many cases formulation of the coupled electromagnetic-thermal problem depends on different factors and peculiarities of microwave technologies realization.
Optimal rotor structure design of interior permanent magnet synchronous machine based on accelerating evolution algorithm using the Kriging metamodel
Authors: Woo Dong-Kyun , Lim Dong-Kuk , Ali Mohammad , Jung Hyun-Kyo
Published: December 2018

This paper presents evolution strategy (ES) assisted by Kriging metamodel to preselect the most promising solutions and reduce the number of fitness function evaluations. The role of Kriging metamodel is to predict an objective function value for a new candidate solution by exploiting information recorded during previous generations. The use of promising solutions for screening the candidate solutions makes it possible to significantly reduce the computational cost of ES. The usefulness of the proposed method is verified by means of mathematical test cases and the optimal rotor structure design of interior permanent magnet synchronous machine.
Load forecasting by regression model based on fuzzy rules
Authors: Phan Binh Thi Thanh , Luong Manh Van
Published: December 2018

The forecasting models by traditional regression function have the crisp functions such as Y=f(x1, x2 ,….,xn) or logY=f(logx1, logx2 ,….,logxn). Here f has the linear form and xi are the factors such as GDP, temperature, industrial output, population… But these models are able to be used only when the linear correlation existed (expressed by the correlation coefficient). This paper introduced the regression model based on the fuzzy Takagi-Sugeno rules. These rules are built by using the subtractive clustering. The model is used for the general case, even when there are no the crisp function f. Examining shows that the good results are obtained in the case of traditional correlation such as linear or linear by logarithm. The results are also satisfactory for the case of unknown correlation. The electricity consumption forecasting due to the temperature factor for one substation of HochiMinh city was carried out.
MASTER’S PROGRAM AS A PERSPECTIVE DIRECTION OF PROFESSIONAL TRAINING OF PEDAGOGICAL PERSONNEL IN THE SPHERE OF INFORMATIZATION OF EDUCATION
Authors: Chusavitina G. N.
Published: December 2018

The article discusses the experience of the implementation of master’s training in the educational program 44.04.01 “Pedagogical education” (“Information technologies in education”) in Nosov Magnitogorsk State Technical University. The article outlines the conceptual foundations of the educational program, shows the structure, reveals the features of the program in terms of positioning in the educational services market. Particular attention is paid to the relationship with the labor market and key employers in the preparation of master's students of teacher education.
COGNITIVIZATION — THE NEXT STAGE OF INFORMATIZATION OF EDUCATION
Authors: Christochevskaya A. S. , Christochevsky S. A.
Published: December 2018

Informatization of education has been going on for 30 years. During this time, a good material and technical base appeared in schools, there are repositories of e-learning resources to which teachers have access. However, it is difficult to use these e-learning resources due to their too large number and not always high level. It is advisable to introduce a system of reviews and recommendations, to conduct a comparative analysis, as well as to make reviews of resources on a particular subject/topic. In addition, the demand for e-learning resources is affected by the fact that education authorities encourage not so much the use of e-learning resources as their development by the teacher himself. In general, the load on teachers has increased instead of the promised saving of time and effort when using the e-learning resources. At the same time, many e-learning resources are not very effective, since they do not meet the requirements of cognitiveness (they contribute not to learning, but to simple memorization of the material). It is necessary to explore the process of learning new material: this will allow you to create cognitive e-learning resources and other resources that would help you with equal probability to successfully acquire new knowledge for students belonging to different psycho-types. At the initial stage of the study of any subject, it is more expedient to use the usual “paper” method, that is, a textbook and not overload the student’s brain with excessive information. Only when he has mastered the basic provisions, we can turn to e-learning resources, bearing in mind that they must be cognitive, that is, they are aimed at logical perception and rapid intuitive learning, only in this case e-learning resources can be considered effective. The conclusion is formulated that cognitiveness is the next stage of informatization of education after the stage of electronization.
Colleges of Education Current Course Contents and Students Carrying Capacity
Authors: Moh'd Kinta , Moh'd Aliyu , John A. Yahaya , Moh'd Layi Abubakar , Tanko Aliyu , B. Moh'd Samaila , J. Brown Ukaegbu , G. Boma Bulus , J. Gbemiga Arowolo , Ibrahim Andrew
Published: December 2018

This study examined the relevance of the quality and quantity of courses offered in colleges of education to account for differences among students. Two research questions and hypotheses were each answered and tested respectively. The study adopted a survey design with a population target that comprised students from colleges of education in the North Central zone of Nigeria. 510 respondents were randomly selected from both federal and state colleges of education proportionately. A “Course Contents Requisite Questionnaire (CCRQ)” was drafted and validated of which its reliability tested with a Cronbach’s coefficient alpha gave .714. The data generated were analysed through descriptive and inferential statistics. Results showed that students found it difficult to properly grasp in-depth knowledge due to too many courses offered; GSE courses offered by students should be reduced and not beyond 200 level; no add and drop options and less than 40% of enrolled candidates complete within three years. It was recommended that a 3-term GSE courses be reduced and terminate at 200 level; NCCE to legitimately organize a workshop to address the inadequacies discovered in structural organization of the current contents; add and drop of course option be available in colleges among others.
试析无人机测绘数据处理关键技术及应用
Authors: 时 斐
Published: December 2018

现阶段,我国的无人测绘市场不断发展,而且需要处理的测绘数据也在不断增多,数据处理技术成为人们关注的焦点。本文主要分析了几种无人机测绘数据处理关键技术,并阐述了技术的应用,以供参考。
关于矿山机电电子设备故障诊断维修问题探讨
Authors: 张 磊
Published: December 2018

矿产资源是支撑我国经济发展的重要资源之一,近年来,我国经济水平得到了快速提升,新矿山也在不断的建设生产,为提升矿山生产效率和质量,矿山企业将大量的机电设备投入生产,由于机电设备产生故障具有不确定性,因此,还需要相关人员能够充分运用故障诊断技术,定期对设备进行保养维修,消除故障隐患,保证矿山稳定生产。