The biological effects of power frequency electric and magnetic fields have been a source of concern for the past many years, especially since 1979 when an epidemiological study report suggested a positive relationship between childhood cancer and exposure to power frequency electromagnetic fields from residential overhead power lines. The extensive studies of dosimetry and biological effects have since been carried out. It is believed that power frequency electromagnetic fields does induce biological effects (no serious threat to human health). The clear explanations for the possible interaction mechanisms remain to be identified. The problem with the study on dosimetry has been lack of theory that applies to the physical interaction of power frequency electric and magnetic fields with humans. At present, it seems to be widely accepted that the density of induced currents in the human body can be used as the decisive parameter in evaluating human exposure to these fields. In order to predict the distribution of induced current density inside a human body exposed to electric fields, magnetic fields, or electric and magnetic fields that coexist, the precise measurements of electromagnetic environments are necessary. According to necessity, the fields have to be characterized in terms of strength, orientation and phase angle. This paper presents: (1) Measurements of power frequency electromagnetic environments in 187kV substation yard and in the vicinity of the ground under 187 kV line using laboratory-made instruments; (2) Development of magnetic field exposure monitor; and (3) Review of state of the art of theoretical dosimetry for electric fields, magnetic fields and combined electric and magnetic fields, and evaluation method of human exposure for the future research.

The studies on the biological effects of ELF electric fields conducted in Japan are reviewed. Among international studies, they are characterized as the studies from the viewpoint of bioengineering. In early studies, the safety standard of high voltage transmission lines was determined by a distinct biological effect, i.e., the sensation of the spark discharge caused by electrostatic induction. In numerical analysis, the field coupling to both animal and human bodies became well understood. Some new measurement techniques were developed which enabled us to evaluate the field exposure on a human body. A system was developed to realize the chronic exposure of an electric field on mice and cats. An optical telemetry technique was developed to measure the physiological response of an animal when it was exposed to an electric field. An ion-current shuttle box was developed to investigate the behavioral change of a rat when it was exposed to an ion-current as well as an electric field. In animal experiments, a mechanism of sensing the field was investigated. The cause of the seasonal change of field sensitivity was found. In cases of chronic exposure, suppression of growth was suspected. In shuttle box studies, an avoidance behavior from an ion-current was quantified. To find whether there are any adverse or beneficial effects of the field exposure on human beings, further study is required to clarify the mechanisms of the biological effects.

An analysis of the circuit for dead angle compensation in the dc-to-dc converter controlled by a magnetic amplifier is presented. This circuit suppresses the dead angle so that the core loss may be reduced without spoiling the current surge suppression characteristics of the magnetic amplifier. The analysis is given by modeling the magnetization characteristics of the core containing the saturation inductance and the reverse recovery of the diode. As a result, the control characteristics of the converter with the compensation circuit are expressed analytically and a limit of compensation is derived theoretically.

An exact analysis for magnetostatic surface wave excitation by a single microstrip is presented. Conventional approaches for such an excitation problem do not explain experimental results in a reasonable manner. The theory proposed here explains radiation resistances obtained by experiments, owing to having considered the edge conditions and an expansion form of excitation current on the microstrip properly.

The exact characteristic equation for the hybrid modes in Goubau line is given. By solving the equation numerically we find the hybrid modes Lnm, defined in this paper. We also examine the propagation and attenuation constants of the hybrid modes. As a result the hybrid K12 mode has the extremely low attenuation at the specific frequency similar to the hybrid K11 mode. The electric field distributions of K11 and L11 modes are plotted.

For analyzing the transient electromagnetic fields caused by electrostatic discharge (ESD), a new ESD model is presented here. Numerical calculation is also given to explain the distinctive phenomenon being well-recognized in the ESD event.

Scattering characteristics of a stratified chiral slab, which is composed of dielectric chiral layers of different material properties and thicknesses, are extensively explored. Design considerations for optical filters are also presented for both the cases of normal and oblique incidence. In the analysis, the incident field is assumed to be a plane monochromatic wave of any arbitrary polarization. The transmitted and reflected electric fields are obtained by noting the fact that the electric field inside a chiral medium is expressed as a sum of the left- and right-circularly polarized plane waves of different phase velocities. Then one can describe the power densities and the Stokes parameters of the transmitted and reflected waves in terms of their field components. As is well known,the Stokes parameters characterize every possible state of polarization of a plane wave. Numerical examples are presented to show the effects of chirality on polarization conversion properties of the stratified chiral slab. The cross- and co-polarized powers and the Stokes parameters of the transmitted and reflected waves are computed for the incident wave of perpendicular polarization. The numerical results demonstrate novel depolarization properties of the slab with application to the design of efficient filters active at the optical region. It is seen from the results that the stratified chiral slab acts as a polarization-conversion transmission filter that passes only a cross-polarized component of the transmitted wave at some frequency band. Furthermore, the slab may be utilized as an antireflection filter for both the cross- and co-po1arized components of the reflected wave at the band region.

The characteristics of an open-boundary Cherenkov laser for an electromagnetic wave with a continuous frequency spectrum are numerically analyzed. A given power spectral density for the input wave is found to get concentrated around the frequency where the spatial growth rate is maximum, as it grows along the electron beam. In addition, the frequency for the maximum growth rate is found to shift gradually to higher values. Furthermore, by gradually increasing the permittivity of the dielectric waveguide along it, we can always get the maximum power spectral density at the frequency where the spatial growth rate initially becomes maximum at the input.

Bi2Sr2Ca1Cu2Ox thick film superconducting shields have been fabricated for use with HTc SQUIDs. Shielding factors and internal noise levels of the shields were measured using a DC SQUID magnetometer. A sample in which BSCCO was coated on the outside of a cylindrical Ag substrate exhibited larger noise levels than that with a sample in which BSCCO was coated on the inside of the Ag cylinder. The difference is explained by the thermally driven (Johnson) noise from the Ag substrate. A sample with the Ag cylinder outside the superconductor and samples with MgO substrates inside the superconductor showed good performance with a shielding factors of 10-8 and internal noise levels which did not exceed the DC SQUID magnetometer resolution (5 fTrms/Hz) at 4.2 K. In addition, the flux relaxation noise of BSCCO superconducting shields was estimated from the relaxation behavior of BSCCO.

Nojima and Fujita have found a universal relation, irrespective of temperatures T, between the reduced field hH/Hir(T) and the reduced quantity of magnetization hysteresis mΔM (T, H)/ΔM (T, H0), where Hir is the irreversibility field and ΔM(T, H) is the hysteresis of magnetization for YBa2Cu3Ox and Bi2Sr2CaCu2Ox films. We could explain this universal relation based on a scaling theory in a three-dimensional superconducting vortex-glass phase. The exponent ν derived by this relation coincides with that obtained by nonlinear I-V characteristics for YBa2Cu3Ox films.

Correlation between the surface-SAR and external magnetic near-field in a realistic head model for 1.5GHz microwave far-field exposure is described. The regression relation is shown between the one gram averaged SAR and squared external magnetic field on the cross sectional perimeter of the head model.

Embossed disks with discrete magnetic tracks and servo marks are proposed and evaluated. The tracks and the servo marks are made by etching the glass substrate. The guard band depth was decided to be 0.2 µm. Using the disks, the head positioning accuracy of 0.09µm (rms) and the recording density of 192 tracks per millimeter were demonstrated.

The authors developed new measuring system (Holographic Pattern Measuring System [HPMS]), which is composed of both techniques of holography and graphic image processing, was used to measure the vibrations of a printed circuit board (PCB) due to operation of a mounted electromagnetic relay on it. The clear vibration patterns were obtained. By using pattern analysis processor, quantitative vibration patterns of the PCB surface were observed. Both the vibration patterns and displacements were changed by edge fixing way of the PCB.

It is shown from a computer analysis that there exists a resonant mode of a surface wave which propagates along Goubau line, and that the attenuation of such a mode is very low. The approximate formula for obtaining the resonant frequency is also given.

The effects of low temperature etching for sub-half micron multi-layer resist are investigated. The low temperature etching with pure O2 gas provides higher anisotropic profiles than with an additional gas such as Cl2, N2. This is caused by the difference in the formative process of the side wall protection. With pure O2 gas at 80, highly anisotropic profiles for 0.35 µm patterns can be performed while the maximum tolerable width loss is below 0.03 µm.

An accurate numerical solution is presented for the electromagnetic scattering from a double strip grating, where the strip planes are each supported by a dielectric slab. This structure is a model of polarization diplexers. The direction of propagation and the polarization of the incident plane wave are arbitrary. We derive a set of singular integral equations and solve it by the moment method, where the Chebyshev polynomials are successfully used as the basis and the testing functions. By numerical computations we examine the dependence of the diplexing properties on grating parameters in detail. The cross-polarization characteristics at skew incidence are also referred. From these results we construct an algorithm for the design of polarization diplexers.

When we study time-domain electromagnetic fields, we frequently use the finite-difference time-domain (FD-TD) method. In this paper, we discuss errors of the FD-TD method and present the optimum mesh spacings in the FD-TD method when the three mesh spacings are different.

A coplanar-type TW electrode is analyzed for the use within a Ti:LiNbO3 optical modulator. The quasistatic analysis is developed based on the variational principle and the incremental inductance formula. The anisotropy of the LiNbO3, the effect of the SiO2 buffer layer, the overlaid conductor and the electrode thickness can be taken into consideration easily by using the extended spectral domain approach (ESDA) as the formulation procedure. It is shown numerically that the TW electrodes thickness, t, and the overlay spacing, p, are as dominant as the buffer layer thickness d, i.e., the microwave effective index and the product ΔfL is affected significantly by the electrodes thickness t and the overlay spacing, whereas the product VπL is insensitive. Therefore, the introduction of the overlaid conductor and the use of thicker electrodes can be utilized effectively to achieve higher values of the figure of merit Δf/Vπ.

This paper theoretically evaluates the external electro-optic (EO) sampling of high-speed electrical signals using poled polymers as materials for a proximity electric-field sensor. Based on the derivation of the half-wave voltage and the analysis of a static electric field coupled to the polymeric media placed over IC interconnections, invasiveness, voltage sensitivity, and spatial resolution have been discussed. The polymeric sensors have shown to be used in contact with the IC interconnections with negligibly small invasiveness, thus making polymeric sensors provide higher sensitivity and spatial resolution than inorganic crystals such as GaAs and KD*P.

In this paper, scattering waves by a strip grating with an anisotropic substrate for the incidence of inclined polarization are analyzed, and polarization characteristics of scatterd waves are calculated. For simplicity, the analysis is limitted to the case of normal incidence and a perfectly conducting strip grating is assumed.