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This paper shows that two apparently independent models of hysteresis--the Jiles-Atherton model, developed by Jiles and Atherton, and the energetic model, developed by Hauser--are mathematically equivalent. These two hysteresis models are examined with respect to their capability to describe the dependence of the magnetization on magnetic field and mechanical stress. Comparisons have been made between the predictions of the two models and measured hysteresis curves. Through a mathematical analysis of the structure of the models, conditions have been found under which both models predict the same magnetization curves. This 'common ground' agreement between the models has allowed us to establish correspondence between the descriptors of the models so that a mathematical transformation between the model parameters becomes possible. The result allows improved interpretation of the physical mechanisms that contribute to ferromagnetic hysteresis at different stages in the magnetization curve in terms of the reversible and irreversible physical processes such as domain wall motion and domain rotation which form the basis of these models. Furthermore, consideration of the internal demagnetizing factor has also allowed it to be included in the models. Index Terms--Anisotropy, demagnetizing factor, energetic model, hysteresis modeling, Jiles-Atherton model, mechanical stress.

Based on the concept of using controllable mixed electric and magnetic coupling to design planar filters in our earlier work, we propose a novel inline coaxial filter, in which the electric and magnetic coupling can be separately controlled. Due to this controllable mixed coupling, the filter can operate with a quasi-elliptic characteristic. By modifying resonator structure and inserting additional coupling components, the filter size is substantially reduced and the coupling becomes more easily controllable, thus being able to produce a highly selective filter with a compact size. In addition, asymmetric response can be easily achieved. For the N-order filter, a maximum of N - 1 finite transmission zeros can be realized. Practical designs, concerning a global system for mobile communication specification, show the advantages of this filter. Index Terms--Coaxial, elliptic filtering characteristic, inline filter, mixed coupling.

In most finite element analysis, the numerical error range of the computed force must be specified. In this paper, an error estimation method for force computation using the virtual work method is presented. The merits of the proposed method include its simplicity and its applicability in force computation when the objects being studied are touching other objects. Index Terms--Error estimation, finite element method (FEM), force, magnetic field.

This paper presents a method for investigating, calculating, and optimizing back-bias magnets used in automotive sensor applications such as ABS/ESP. The performance of these applications crucially depends on the choice of magnet. Major parameters, such as shape and direction of magnetization, are investigated and optimized for different types of magnets. The calculations were performed using finite-element method simulations in 3-D. Index Terms--Magnetic fields, magnets, modeling, simulation software.

This paper discusses interface conditions used in a domain partitioning method and their approximation with a reduced number of degrees of freedom called hooks. In the electrostatic and magnetostatic cases, electric or magnetic hook-connectors are, respectively, used to describe interactions. Better numerical results are obtained in the full wave regime by using both electric and magnetic hooks. This paper proposes an efficient approximation of the interface conditions by using a coarser grid on this surface. We have shown that the interface tends to become transparent for the electromagnetic (EM) field, when the number of hooks is increased and consider this convergence property as the main result of the paper. The proposed domain partitioning (DP) method was successfully applied as a particular domain decomposition (DD) technique for the EM modeling with parallel algorithms of RF-IC components. Unlike DD which is an iterative approach, the new DP approach is a direct one. The sub-domain models being independently extracted, DP is more effective and suitable for parallelization. The open problem of hooks identification is reformulated as a discrete optimization problem. Index Terms--Domain decomposition (DD)/partitioning, electromagnetic (EM) analysis, electromagnetic (EM) circuit element, finite integration technique (FIT).

Hierarchic families of finite elements are widely used in higher order finite-element methods. Several hierarchic sets of basis functions for nodal, edge, and face elements are proposed by different authors in scientific literature. However, no general methodology exists for their construction. This paper presents an analysis of hierarchic families of finite elements which leads to the localization of their degrees of freedom. From this localization, we derive an algebraic approach for the construction of hierarchic families of nodal, edge, and face elements. The case of tetrahedral finite elements is discussed in detail. Index Terms--Basis functions, degrees of freedom, hierarchic families, higher order finite-element methods.

Graphics Processing Units (GPUs) for years have been dedicated mostly to real time rendering. Recently leading GPU manufactures have extended their research area and decided to support also graphics computing. In this paper, we describe an impact of new GPU features on development process of an efficient Finite Difference Time Domain (FDTD) implementation. Index Terms--FDTD, GPU, massively parallel computing.

The line-search technique was usually introduced to the Newton-Raphson (NR) method in order to improve the convergence characteristic of nonlinear magnetic field analysis with the toughness magnetic nonlinearlity. In this paper, we proposed the NR method combined with the optimal step size using exact functional minimization in every nonlinear iteration. The convergence process and computation time were investigated, and compared with the conventional line-search technique using the approximate functional minimization. Index Terms--Energy functional, exact minimization, line-search, Newton-Raphson (NR) method, nonlinear magnetic field analysis.

A new type of low voltage circuit breaker with permanent magnet (PM) actuator is proposed. The magnetic field is computed using finite element method (FEM) to find out the relationship among the flux linkage, displacement and different currents and these information are stored in a look-up table. The control model, which is built in Matlab, is connected with the Adams model via input and output interfaces. The transient co-simulation is used to study the making process. Experiments are carried out on a prototype to validate the proposed method. Index Terms--Low voltage circuit breaker, permanent magnet actuator, transient co-simulation.

A field-circuit coupling method is presented, whose basic idea is to extract from the finite-element (FE) model a linearized lumped parameter representation of the electrical machines, to be used in the circuit simulator model of the power electronic supply. The dynamic coupled model of the complete drive obtained this way can be iterated over a limited period of time, with a time step adapted to the high frequency of electronic commutations. When the temporary representation of the machine has come, or is expected to have come under a given accuracy threshold, a new FE simulation is performed, a new set of lumped is generated and the process is repeated. This method allows decoupling the time constants of the field problem from that of the circuit problem, which is typically one or two orders of magnitude smaller. This yields a considerable saving of computation time with a controllable, at least a posteriori, loss of accuracy. Index Terms--Electric machines, energy-based linearization, field-circuit coupling, finite element methods.

In this paper, a new time-domain integral equation solution method for arbitrarily shaped, perfectly conducting thin-wire antennas is presented. The space-time discretization of the circumferentially invariant electric current along the wire axis is achieved by employing higher order hierarchical polynomials for the spatial basis functions and discretely causal piecewise polynomial interpolation functions for the temporal basis functions. The solution of the transient current along the wire is obtained by marching-on-in-time (MOT). The hierarchical nature of the spatial basis functions enables the efficient assembly of the space-time impedance matrices. Rigorous evaluation of the time-domain wire kernels is presented. Numerical test cases demonstrate the validity, accuracy, and applicability of the new method. Index Terms--Antennas, hierarchical field approximation, integral equations, time-domain analysis, transient analysis.

The influence of stratified earth on the wave propagation characteristics of overhead conductors is analyzed, using a generalized two-layer earth model of varying electromagnetic characteristics. A systematic comparison to simpler stratified earth models is presented, showing the differences in the propagation characteristics. Index Terms--Earth return admittance, earth return impedance, multiconductor lines, nonhomogenous earth.

A method of magnetic field analysis which takes eddy currents into account in laminated steel core is extended into loss calculation to investigate the loss reduction of reactor connected to inverter power supply. In the proposed method, the iron loss in the laminated core can be calculated considering the flux and eddy current distributions in steel plate affected by harmonic components. The proposed method is applied to a single-phase model of reactor connected to inverter power supply and the loss distributions are demonstrated in detail. Moreover, in order to reduce the loss, the shape configurations of core and plate are improved. Finally, the experiments using three-phase reactors are carried out to verify the calculation and investigate the effectiveness of the proposed shape configuration. Index Terms--Inverter power supply, iron loss, laminated core, magnetic field analysis, reactor.

The paper introduces the concept of the complex inductance as a parameter of a coil loaded by sinusoidal current and placed near an electrically well conductive body in which the magnetic field of the coil induces eddy currents. Studied will be only axi-symmetric cylindrical coils and the paper shows how easily their complex inductances can be determined by means of professional programs for electromagnetic field analysis. The suggested methodology is illustrated on computation of the inductance of a ring coil placed near a conductive slab. Investigated is also dependence of the complex inductance on frequency. Index Terms--Coil inductance, eddy currents, quasi-stationary electromagnetic field.

This paper presents a torque analysis of an axial flux permanent magnet synchronous machine (AFPMSM) based on analytical analysis of magnetic field. The proposed method for torque analysis requires less computational time and is more flexible than finite element method (FEM). This is important advantage, especially for the early stages of the design process. Torque measurements on prototype AFPMSM confirm the validity of the torque analysis method. Index Terms--Electric machines, magnetic fields, permanent magnet machines, synchronous machines, torque.

The time stepping finite element method based on the backward Euler's method has been widely used to simulate transient electromagnetic fields. Because of the numerical error of nonlinear iterations, the solutions of the derivative quantities may have very big noisy spikes. We present a modified formulation that reduces significantly the numerical error of the derivative quantities in transient finite element analysis of magnetic field computation. We also present an example that simulates the operation of an induction motor and demonstrates that the new method can successfully remove the spikes in the calculated waveforms of back electromotive force and eddy-current loss. Index Terms--Finite element method, magnetic field, nonlinear, numerical error, transient.

Field modeling becomes simpler if strong field nonuniformities are solved theoretically. The early obtained formulas for 2-D 'corner' and 'constriction' permeances pertain to right angle configurations. In this paper, using a conformal mapping, the field in the vicinity of arbitrary angle vertex is studied and the fringing permeance determined. The results are applied to permeance evaluation of lunate cross section grooves from the rotors of certain types of reluctance motors. Closed-form expressions are obtained, in good agreement with finite element analysis. Combined with the finite element method, obtained results offer the possibility to make simpler and more accurate analytical calculations of motors and other magnetic devices and to better evaluate magnetic forces that act on them. Index Terms--Conform mapping, corner permeance, fringing flux, 2-D electric and magnetic field.

As a kind of maneuverable pulsed power supply (PPS), the Magnetic Flux Compression Generator (MFCG) can be used in many military fields, but the MFCG concept has not been explored systematically. The definitions of MFCG were given in two ways: the electric circuit model and the magnetic field model, and the latter was indispensable to resolve many technical difficulties. According to the field model, the working principles of the MFCG with perfect solenoid were shown as the magnetic flux conservation or the magnetic flux linkage conservation. The inherent coherence of the two definitions was also outlined. The names of MFCGs were discussed, and the distinguishing features of MFCG from other pulsed generators were summarized. According to the different forms of the windings and the different moving modes of the armatures, 14 kinds of MFCGs were classified systematically, and their characteristics were generalized respectively. The most useful kinds of MFCGs were the piston type, the explosive one, and the rotary one. The key technology of the piston type MFCG was analyzed and the conclusion is that the conical armature without any longitudinal slits on its surface is necessary. The working process of the two stages explosive MFCG for the microwave bomb was reviewed: the first stage as a magnetic energy accumulator, and the second as an ordinary pulsed generator. The CPA, as a kind of rotary MFCG, was developed as a kind of drum alternator in the big ship to power the EM launcher. The essential work was important for MFCG concept, theory research, technology development, and military applications. Index Terms--Magnetic flux compression generator (MFCG), military applications, new concept weapons, pulsed power supply.

There is a need in industry to supply safe, economical, and reliable techniques to characterize surface treatments such as case hardening and peening of steel components and structures, both at the manufacturing stage and in service. Magnetic Barkhausen emission (MBE) has proved successful for these tasks, but has severe limitations in terms of measurement depth of the technique and deeper treatments such as laser peening and case hardening often fall outside the scope of MBE inspection. The domain wall motion that generates MBE also causes a release of elastic energy known as magneto-acoustic emission (MAE), which has a much greater measurement depth, and so offers a complementary technique to extend the measurement depth for the characterization of surface treatments in steel. In this paper, comparative MBE and MAE results from case hardened En36 gear steels are presented in the form of signal profiles and correlations are drawn between MBE and MAE profile features and domain activity within the soft core and the case hardened layer. The results show that the overall amplitudes for both MBE and MAE exhibit a good correlation with case depth, but profile analysis for MAE is ambiguous, so possible interpretations of the MAE profile are discussed. Index Terms--Case depth, case hardening, En36 steel, magnetic Barkhausen emission, magneto-acoustic emission, nondestructive evaluation, tempering.

Magnetic anomaly detection is a good method for detecting ferromagnetic objects, particularly hidden targets. In this work, we address the detection of a moving ferromagnetic target using a static three-axis referenced magnetometer. The analysis and the results are also applicable to the converse case of a static ferromagnetic target and a moving three-axis referenced magnetometer. We use the three magnetometer outputs to build a total magnetic field of the target. This signal is decomposed into a set of orthonormal basis functions, out of which the dominant basis function is chosen as the detector. The detector provides output responses to any target magnetic moment orientation. We support the analysis by a computer simulation and real-world experimental results. The high detection probability and the simple implementation of the proposed method make it attractive for real-time applications. Index Terms--Magnetic anomaly detection (MAD), orthonormal basis functions, three-axis referenced magnetometer.

In this paper, magnetic shielding of electric wires by a wall of magnetic material is considered. It has been commonly believed over 100 years that magnetic materials should be arranged without any space between them to achieve a sufficient magnetic shielding effect. However, it was newly found that a wall made by aligned strips with gaps could achieve almost the same effect of magnetic shielding as a wall with the aforementioned conventional method, which is a complete plate without any gap. In this paper, this new method using aligned strips with gaps is called open-type magnetic shielding method. Furthermore, it was found that sufficient magnetic shielding effect can be achieved with sizable gaps. Therefore, the advantage that light and air can pass through the wall with open-type magnetic shielding method will create a wide range of applications. This study reports the features of a wall with the open-type magnetic shielding method with some experimental data about interval between strips, layers, rotation of strips, and so on. Index Terms--Electromagnetic compatibility, magnetic fields, magnetic shielding, shielding, silicon steel.

Magnetocaloric [Gd.sub.5][Si.sub.2][Ge.sub.2]-based alloys exhibit a well-documented giant magnetocaloric effect at around room temperature. However, as candidate materials for real-world refrigeration devices, they suffer from a number of problems, one of which is large hysteresis losses while cycling in and out of the magnetic field. It has, however, been reported that a small amount of iron reduces these hysteresis losses very significantly, so increasing the total potential cooling capacity of the material. We have investigated the magnetic properties as well as the macro- and microstructural changes for a wide range of iron substitutions for silicon, according to the formula [Gd.sub.5][Si.sub.2-x][Fe.sub.x][Ge.sub.2], where x was varied between 0 and 1. The samples were prepared with an arc- melter and homogenized in an inert atmosphere, after which they were analyzed with a nano-resolution field-emission-gun scanning electron microscope (FEG SEM) and an X-ray diffractometer. The magnetic measurements were made with a cryogenic vibrating-sample magnetometer. The substitution of silicon for iron presented us with some unusual macrostructures and a consistent change in the microstructures of the samples. While most of the iron forms part of the grain-boundary phases, it also results in the formation of a new [Gd.sub.5][(SiGe).sub.3] main phase. We also observed that the addition of iron lowered the Curie temperature of the alloy, but only had a minimal effect on reducing the hysteresis losses, suggesting that this previously observed reduction in the hysteresis losses only occurs with very small substitutions of iron. Index Terms--[Gd.sub.5][Si.sub.2][Ge.sub.2]-type alloys, magnetic hysteresis, magnetocaloric effect, microstructure.

This paper provides an analytical approach for calculating the critical temperature in a magnetic component above which thermal runaway takes place. Thermal runaway implies that there is no steady-state balance between the generation of heat due to core and winding losses and the removal of heat by convection and radiation. The temperature in the magnetic component increases until a new balance is achieved at a much higher temperature close to the Curie temperature. The magnetic loss, as provided by manufacturers, is expressed as a quadratic function of temperature. The impact of the ambient temperature and winding losses on the critical temperature for a magnetic component is also included in the analysis. Index Terms--Critical temperature, thermal runaway.

Friction and stiction problems often occur in microsensors and microactuators. An original solution proposed here consists in diamagnetic levitation above integrated micromagnets. This static, energy free, room temperature levitation is seldom used because of the weakness of the forces involved. However, scale reduction enhances diamagnetic volume forces. Therefore, levitation is easily obtained at the microscale. In this work, the levitation of a microparticle of bismuth is studied. Static and dynamic simulations are presented and confronted to experiments. The static simulations enable one to find the location and to quantify the stability of levitation. Dynamic simulations are required to fully explain the results of the experiments proposed. The structure is then fabricated and successful levitation of bismuth in air and copper and silicon in paramagnetic water is reported. Applications in material conveyance, inertial sensors such as inclinometer or accelerometer are explored. Index Terms--Diamagnetism, levitation, microactuator, microsensors.

The design and characteristic analysis on the linear synchronous motor (LSM) for high-speed maglev propulsion is discussed. We describe the techniques for the design, analysis, construction, and experiment of a prototype propulsion system with short-stator LSM. On the basis of a 2-D analytical field analysis, this paper predicts the magnetic field due to dc excitation and three-phase winding current, the back-EMF, and the electromagnetic torque characteristics. The results are validated extensively by comparison with finite-element analysis and experiment. The propulsion performance was tested by using a high-speed rotary type test wheel with linear peripheral speed up to 283 km/h. Index Terms--Analytical field analysis, linear synchronous motor (LSM), maglev, magnetic propulsion.

This paper describes the analysis and experimental verification of a short-stroke, single-phase, quasi-Halbach magnetized tubular permanent magnet motor in which the magnets are mounted on a nonmagnetic support tube. Analytical solutions for the magnetic field distribution in the airspace and magnet regions are established in the cylindrical coordinate system. The analytically predicted static performance of a prototype motor is validated by finite element predictions and measurements. Index Terms--Linear motor, permanent magnet (PM) machines, single-phase motor, soft magnetic composite (SMC).

This paper presents the analytical analysis of magnetic field and back electromotive force (back EMF) calculation in an axial flux permanent magnet synchronous generator (AFPMSG) without stator core. For the verification, the numerical analysis [finite element method (FEM)] of magnetic field is accomplished and comparison between analytical and numerical solution of magnetic field is presented. Both analytical and numerical solutions are obtained via magnetic vector potential, respectively. This paper also presents the comparison between analytical solution and numerical (FEM) solution of back EMF using Faraday's law. The verifications show that good agreement between analytical and numerical solution of magnetic field and back EMF is obtained. The validity of the proposed analytical method is additionally confirmed with measurements of back EMF on prototype AFPMSG with coreless stator. Index Terms--Electric machines, finite element methods, magnetic fields, permanent magnet generators, synchronous generators.

The rotational loss is one of the most important problems in high-power flywheel energy storage system (FESS) which supplies the electrical energy from the mechanical rotation energy. In our FESS with PM synchronous motor/generator (PMSM/G) and non-contacting system, the rotational loss is mainly generated in the laminated iron stator when PM rotor mounted on the flywheel is rotated. Therefore, this paper presents design and evaluation of a PMSM/G model composed of double-sided Halbach magnetized PM rotor and ironless 3-phase winding stator to minimize speed reduction of the flywheel. For one such motor structure we give analytical formulae for its magnetic field and back-electromotive force in a uniform way via the magnetic vector potential. As a result of experiment, dynamic performance of a manufactured double-sided PMSM/G is evaluated by comparison with those of the slotless PMSM/G in the idling mode. The result shows that the presented PMSM/G can be applicable to the high-power FESS. Index Terms--Coreless 3-phase winding stator, double-sided PMSM/G, Halbach magnetized PM rotor, high power FESS.

This paper reminds the drawbacks of classical voice-coil motors and presents a way to improve them. Two ironless and leakage free structures are presented, one using traditional sintered magnets and the other one using bonded magnets, giving the pros and cons of each solution. A 2-D analytical model using the Coulombian approach is used to calculate and compare the performances of both structures. Then, in order to evaluate the relevance of the 2-D model for magnet rings, a comparison is done with a 3-D analytical model for several radii of rings. Index Terms--Bonded magnets, loudspeakers, magnetic field analytical calculations, permanent magnet rings.

Considerable enhancement of magnetic properties was attained in nanophase [RE.sub.12][Fe.sub.82] [B.sub.6] -base melt spun alloys (RE = Nd, Nd + Pr) by means of B excess content (10 at%) and Zr-Co addition (2% and 7%, respectively). The intrinsic coercivity exhibited a marked improvement (respect to the stoichiometric 6 at% B alloy) within the range 50%-65%, with a maximum of 1161 [+ or -] 14 kA/m for the B-rich and Zr-containing alloy, together with an excellent combination of remanence and energy density values of 0.90 [+ or -] 0.01 T and 137 [+ or -] 4 kJ/[m.sup.3], respectively. Further Co addition led to a Curie temperature enlargement (350[degrees]C) preserving high coercivity (1176 [+ or -] 31 kA/m) and useful energy densities (119 [+ or -] 4 kJ/[m.sup.3]). Results were interpreted on the basis of microstructure and intrinsic magnetic property variations, together with micromagnetic calculations. Index Terms--Hard magnetic alloys, high coercivity alloys, micromagnetism.

We present here a magnetic and [sup.57]Fe Mossbauer spectral study of the Lu[([Al.sub.1-x][Fe.sub.x]).sub.2] compounds (x = 0.50, 0.75, and 1). At relatively high temperatures ([T.sub.H] ~ 300 K for x = 0.75, and [T.sub.H] ~ 70 K for x = 0.50) a peak is observed in both zero field cooled magnetization, M(T), and low field ac susceptibility versus temperature, [X.sub.ac](T), curves. Irreversible phenomena occur at temperatures below the maxima in M(T), and a clear dependence with the exciting frequency is observed in the [X.sub.ac](T) curves. Similar behavior is observed at lower temperatures ([T.sub.L] ~ 45 K for x = 0.75, and [T.sub.L] ~ 10 K for x = 0.50); however, the low temperature peak in [X.sub.ac](T) is almost frequency independent. The combined analysis of magnetization data and [sup.57]Fe Mossbauer spectroscopy suggests that the high temperature process corresponds to the apparition of short-range correlations between the magnetic moments, which lead to the formation of magnetic clusters, whereas the low temperature process corresponds to a freezing of the iron magnetic moments. Index Terms--Iron and rare-earth compounds, magnetic materials, Mossbauer spectroscopy.

This paper describes an optimal length and combination of short shield ducts to prevent the leakage of magnetic flux through the openings of a double-layered magnetically shielded room (MSR) used for electron-beam lithography systems and biomagnetic measurements. A number of openings as large as 500 x 500 mm must be provided in the walls, ceiling, and floor of such MSRs for air conditioning and cables. First, the magnetic field leakage from the openings, using a small model of an MSR, was measured with short shield ducts of various lengths in order to confirm the validity of the analysis and practical realization. Next, the distributions of the magnetic fields inside the small model were evaluated using 3-D magnetic field analysis and the finite element method. The method of analysis was verified by comparing computed results with those measured. We show the optimal length of shield duct attached around the openings as follows: The optimal combination of short shield ducts is an outer layer duct which is the same length as the width of the opening with an inner layer duct which is half the length of the opening. These lengths of duct accord with the optimal lengths when the outer and inner layer ducts are employed as a single duct. The leakage flux of the optimal single duct through the opening can be decreased to a half by the optimal combination of shield ducts. This also corresponds to the fact that the length of the inner layer duct should not protrude from the outer layer in order to avoid collecting surplus fluxes outside the magnetically shielded room. Index Terms--Magnetic flux leakage, magnetic shielded box, multilayered magnetically shielded room, opening, shield duct, 3-D magnetic field analysis.

Magnetic bearings, which can suspend rotor shafts by electromagnetic force without mechanical contacts and lubrication, have been developed and commercialized. In the various types of magnetic bearings, thrust magnetic bearings with thrust disks are generally used for active suspension control of thrust direction. However, the large thrust disks of the thrust magnetic bearings have caused various problems. Therefore, this paper proposes a novel structure of an active thrust magnetic bearing using a cylindrical rotor core without the large thrust disk, and it is shown with 3-D-FEA and experiment that the proposed thrust magnetic bearing with the cylindrical rotor core is effective in producing thrust force. Index Terms--Active suspension control, magnetic bearings (MBs), magnetic suspension, thrust magnetic bearings (TMBs).

To improve the comfort of hospital patients, we have developed a new open-type magnetically shielded room (MSR) for magnetic resonance imaging (MRI), constructed by stacking square cylinders composed of magnetic material on the inside and a conductive material on the outside. The magnetic cylinder shields against leakage of the magnetic field from the MRI, while the conductive outer cylinder prevents intrusion of the electromagnetic field from outside by waveguide attenuation. First, the optimal design of the magnetic cylinder was determined, using 3-D magnetic field analysis with a simple cubic MSR. Second, the validity of the analysis and the practical realization of the designed MSR were investigated using a small experimental model. Finally, from a design perspective and the standpoint of saving space, the optimal combination of electromagnetically shielded glass and conductive cylinders made of aluminum was studied by measuring the electromagnetic shielding effect. As the optimal design of an open-type MSR for an MRI, we have adopted a combination of single-layered electromagnetically shielded glass together with stacked cylinders. These cylinders are made of a square cylinder, 144 x 144 mm and 300 mm long, made of silicon steel (thickness t = 1 mm) and divided into three parts along the axial direction, placed inside a second square cylinder made of aluminum, 150 x 150 mm and 300 mm long (t = 3 mm). This MSR construction technique creates an open, spacious feeling inside the facility and can be easily fabricated at low cost. Index Terms--Electromagnetic field, leakage magnetic field, magnetic resonance imaging, multilayered magnetically shielded room, opening.

Integrated solenoid inductors with magnetic core were fabricated and analyzed. An inductance above 70 nH was achieved while keeping the coil resistance below 1 [OMEGA] and the device area below 1 [mm.sup.2] using a solenoid design with a single magnetic layer. The inductance of the magnetic inductor was more than 30 times that of the air core inductor of the identical geometry, and the quality factor of the magnetic inductor was >5. Novel inductor designs and the scalability were also examined, and an inductance density higher than 200 nH/[mm.sup.2] was obtained. The measured device properties and engineering tradeoffs were well explained by analytical models we developed. Index Terms--Amorphous magnetic film, magnetic losses, permeability, power delivery applications, thin film inductor.

This paper deals with the thrust calculations and the measurements of a cylindrical linear oscillatory actuator (LOA) using transfer relations theorem (TRT), namely, Melcher's methodology. Using transfer relations derived in terms of a magnetic vector potential and a two-dimensional (2-D) cylindrical coordinate system, this paper derives analytical solutions for the magnetic vector potential, magnetic fields due to permanent magnets (PMs), and stator winding currents and the thrust. The analytical results are validated by nonlinear finite element (FE) analyses. In particular, test results such as thrust and back-EMF (electromotive force) measurements are given to confirm the analysis. Index Terms--Cylindrical linear oscillatory actuator, transfer relations theorem, trust calculations.

The transverse flux machine (TFM) is a promising driving machine, especially for the low-speed applications, because it has greater power density, torque, and efficiency than the conventional electrical motors. However, the TFM has a complicated structure, a large torque ripple, and, occasionally, an unbalanced magnetic force. This paper investigates the effects of teeth geometry on torque ripple and unbalanced magnetic force in a rotatory two-phase TFM using the 3-D finite element method, and proposes a rotatory two-phase TFM with herringbone teeth to reduce the torque ripple and eliminate the unbalanced magnetic force. Index Terms--Herringbone teeth, torque ripple, transverse flux machine (TFM), unbalanced magnetic force.

In this paper, we have developed the flexible polyimide based magnetostrictive multibody actuators and investigated the magnetomechanical characteristics of TbFe/Ni/TbFe layered thin film sputtered on the polyimide substrate with different thickness ratios for micro devices. The developed actuator is operated by magnetic field applied along with the length direction of each cantilever of the multibody design. In the fabrication process, micromachining techniques are adopted for the design of multicantilever shape of flexible polyimide substrate, thicknesses of 127 [micro]m. And TbFe/Ni/TbFe multilayer films with thicknesses of 0.2/0.1/0.2, 0.1/0.1/0 [micro]m are sputter deposited on the cantilever part of the actuator using designed mask (500 [micro]m thick) for selective dc magnetron sputtering. After the sputter process, X-ray diffraction studies are also carried out to determine the film structure and thickness of the sputtered film. As results, magnetization and magnetostriction of each actuator are measured, and discussed the results of external magnetic field lower than 0.5 T for micro-systems applications. Index Terms--Magnetostriction, microactuators, micromachining, multilayer, thin films.

In order to take advantage of the high sensitivity in magneto-resistance based field sensor, 1/f noise must be minimized for low frequency field measurement. We propose a novel thermally modulated flux concentrator design, which can mitigate the 1/f noise by shifting the measurement frequency to kHz range. The proposed flux concentrator is made of the materials with Curie points around operation temperature. Numerical simulation demonstrated the feasibility of kHz temperature modulation of 20[degrees]C around the Curie temperature. Modulation efficiency can be significantly higher than state-of-the-art flux concentrators. In addition, the numerical simulation also demonstrated the robustness of the thermal modulation on flux concentrator against various nonidealities. Index Terms--Curie Point, flux concentrator, magnetic sensor, 1/f noise.