We fabricated the first Fe-coated fiber probe for magneto-optical applications. In order to improve the optical confinement capability, we used a double-layer structure, with a thin coating of Au. The double-layer structure consisted of 50-nm-thick Fe and 50-nm-thick Au. A probe-to-probe experiment confirmed that the fabricated fiber probe had an effective optical confinement capability for optical near-field measurement.

This paper presents the basic characteristics of a forced resonant type EMI dipole antenna for frequencies below 80 MHz in which two reactance elements are used for the impedance matching at the feed point. The input impedance of the short dipole less than half-wavelength is controlled by the properly determined loading position and the value of loading reactance. The integral equation for unknown current distribution is solved by Galerkin's method of moments with piecewise sinusoidal functions. The numerical results show that the small-sized EMI dipole antenna with lower antenna factors for frequencies below 80 MHz can be realized by the reactance loading. In case the proposed center driven small-sized EMI dipole antenna with 0.3λ length is loaded c=0.133λ from the center, the input impedance is matched at feed line with 50 Ω, and hence the antenna has lower factors in the frequency range of 30 to 80 MHz. Also the normalized site attenuation characteristics are presented for the forced resonant type EMI dipole antenna.

This paper describes the behavior of voids that were formed due to electromigration and diffusion in the interconnections of gold during a DC bias tests of GaAs ICs to current densities in the interconnections of 0.67 106 A/cm2 to 1.27 106 A/cm2 in the high temperature range of 230 to 260. We have found that the voids were formed at the centers in the cross sections of the interconnections and that gold is left around the voids, which means current still flows after the void formation. We have carefully observed the movement of the anode and cathode side edge of the voids during the tests and found that edges moved toward the cathode, in the direction opposite to the electron flow. This direction is constant. Also, the voids are extended, which means that the velocity of the cathode side edge is greater than that of the anode side edge. The velocity of the edges almost proportionally increased with the current density. The constant edge movement direction and the velocity of the edge dependence on the current density suggest that one of the causes of the edge movement is electromigration. The velocity of the edge depends on the distance between the anode side edge of the void and the through hole. The velocity increases in accordance with a decrease in the distance. This means that one of the causes of the edge movement is the diffusion of gold atoms by a concentration and pressure gradient. The GaAs IC failed at almost the same time as the voids appeared. It is important for reliability to prevent the formation of voids caused by electromigration and diffusion.

Write linear density limit is defined to analyze the magnetic recording process in computer hard disk drives at extremely high recording densities. The digital data with pseudo random sequences are recorded numerically in longitudinal media at different densities by a micromagnetic simulation model. A thin film write head and an ideal GMR read head are utilized in the record and read-back process, respectively. A novel method has been utilized to study the write linear density limit: the simulated read back voltage and the respected linear superposed pulses are compared to find the distortion in the record process. When a severe distortion shows up, the corresponding linear density is considered as the write linear density limit. By the novel method, the write linear density limit is analyzed with different parameters of the recording media.

This paper presents an iterative algorithm for decoding product codes based on syndrome decoding of component codes. This algorithm is devised to achieve an effective trade-off between error performance and decoding complexity. A simplified list decoding algorithm, which uses a modified syndrome decoding method, for linear block codes is devised to deliver soft outputs for iterative decoding of product codes. By adjusting the size of the list, the decoder can achieve a proper trade-off between decoding complexity and performance. Compared to the other iterative decoding algorithms for product codes, the proposed algorithm has lower complexity while offers at least the same performance, which is demonstrated by analyses and simulations. The proposed algorithm has been simulated for BPSK and 16-QAM modulations over both the additive white Gaussian noise (AWGN) and Raleigh fading channels. This paper also presents an efficient scheme for applying product codes and their punctured versions. This scheme can be implemented with variable packet size and channel data block.

A simplified model is set up to study the high frequency response in a thin film head, where two pieces of Fe-Al-N films are placed parallel to each other with opposite alternating external magnetic field applied. In this model, the frequency response of magnetic clusters is calculated by a micromagnetic model based on the Landau-Lifshitz-Gilbert equations, and the initial permeability of mesoscopic Fe-Al-N thin films is analyzed in a wide frequency region from 10 to 5000 MHz. The model of a soft magnetic thin film is built up on the ripple structure of the anisotropy field of magnetic clusters. The magnetization interaction between the two Fe-Al-N films is carefully computed to find its effect on the frequency response. The frequency response in a single mesoscopic Fe-Al-N thin film is carefully studied in advance.

Metal particulate tape is one of the most advanced tape media to offer excellent performance at high recording densities. An accurate micromagnetic model of the metal particulate tape has been developed to analyze the magnetic properties of MP tapes. Both particle size distributions and orientation distribution are included in the model, and the magnetostatic interactions among particles are accurately calculated with the shape of ellipsoids. A partial mean field approximation applied in the calculation is proved to be effective by M-H loop analysis.

The transient phenomenon of electromagnetic waves caused by a time dependent resistive screen in a waveguide is treated by using Wiener-Hopf technique. A boundary-value problem is formulated to describe the phenomenon, in which the resistivity of screen varies from infinite to zero in dependence on time. Application of the Fourier transformation with respect to time derives a Wiener-Hopf equation, which is solved by a commonly known decomposition procedure. The transient field is derived from the solution of the equation in terms of the Fourier inverse transform. By using the incomplete Lipschitz-Hankel integral for the computation of the field, numerical examples are given and the transient phenomenon is discussed.

An algorithm for augmenting a binary linear code is presented. The input to the code augmenting algorithm is (n,k,d) code C and the output is an (n,k*,d) augmented code C (k* k) satisfying C C and the Gilbert bound. The algorithm can be considered as an efficient implementation of the proof of Gilbert bound; for a given binary linear code C, the algorithm first finds a coset leader with the largest weight. If the weight of the coset leader is greater than or equal to the minimum distance of C, the coset leader is included to the basis of C.

The radar cross section (RCS) of a dielectric-coated cylindrical cavity was measured and the measurements were compared with those calculated according to the iterative physical optics (IPO). The IPO analysis used the equivalent-impedance boundary condition (EIBC) based on transmission-line theory which takes into account the thickness of the coating. It was consequently found that this condition is much more effective than the ordinary-impedance boundary condition based on the intrinsic impedance of the material.

The purpose of this paper is to improve the detection sensitivity of radio interferometry. The development of wideband signal processing techniques is necessary for high-sensitivity radio interferometry. The higher-order sampling technique can achieve wider bandwidth than expensive wide-baseband conversion system. The over sampling technique can improve the quantization loss from 11.89% to 3.99% at the 4-level quantized sampling. Moreover, the digital filter can reduce the folding noise incurred by the non-rectangular frequency response at a sampling process. It is confirmed that the wideband and low-loss A/D conversion system may be realized by implementing the higher-order sampling, over sampling and digital filtering techniques. In this paper, the key features focusing on these advanced techniques for radio astronomy are presented in detail.

In this paper, we show that a priori probabilities of information bits can be incorporated into metrics for syndrome decoding. Then it is confirmed that soft-in/soft-out decoding is also possible for syndrome decoding in the same way as for Viterbi decoding. The derived results again show that the two decoding algorithms are dual to each other.

We have recently developed a programmable composite noise generator (P-CNG) which can easily control noise parameters such as average power, time-based amplitude probability distribution (APD), crossing rate distribution, occurrence frequency distribution and burst duration. Two applications of the P-CNG are demonstrated to show its usefulness. For the first application, Middleton's Class A noise is simulated. A method of setting parameters for Class A noise is demonstrated. The APD of P-CNG output is in good agreement with that of true Class A noise. In the second application, the P-CNG is used for subjective evaluation test (opinion test) of TV picture degradation. Five simple composite noise models with two kinds of APD are used. Other parameters such as average power are kept constant. Experimental results show that the envelope and APD of composite noises do not greatly influence the subjective evaluation. Finally the capabilities of the P-CNG are shown.

The adsorption behavior of cytochrome c was investigated using slab optical waveguide (SOWG) absorption spectroscopy at the near ultraviolet region utilizing thin quartz plates as planar waveguides. SOWG absorption spectra of cytochrome c measured at constant time intervals showed significant influence of surface hydrophilicity and solution chemistry on the adsorption of this important heme protein in quartz surface. Being polar and typically amphoteric, the protein preferred adsorption on hydrophilic surface than on hydrophobic surface as implied by the lower absorbance data obtained in the latter than in the former. At lower ionic strength and in the absence of buffer, the protein molecules tend to adsorb on the quartz surface. Plots of near steady-state absorbance versus protein concentration follow hyperbolic pattern in the absence of buffer or at low ionic strength and become more linear as the buffer concentration is increased. The results presented here are explained in terms of the general qualitative understanding of protein adsorption at solid-aqueous interfaces and further aids in elucidating the properties of protein monolayers and films.

In this paper, we describe design considerations for inverse dispersion fiber (IDF) whose chromatic dispersion is designed to compensate for that of conventional 1.3 µm zero-dispersion single-mode fiber (SMF). We clarify the appropriate structural parameters for W-type, triple-clad-type and ring-type refractive index profiles to realize a hybrid transmission line composed of SMF and IDF taking into consideration the bending sensitivity and the available wavelength bandwidth that achieves an average chromatic dispersion of below 1 ps/nm/km in the 1.55 µm region. We also show that, when the launched power is less than 0 dBm/ch, a hybrid transmission line composed of SMF and IDF provides better 40 Gbps 8 ch dense wavelength division multiplexing (DWDM) transmission performance than a conventional dispersion compensation scheme with a dispersion compensating fiber (DCF) module.

In this paper, a CMOS data recovery PLL for DVD-ROM is described. Some techniques have been introduced to alleviate the specifications required to analog circuits. A new phase detector alleviates the timing specification of a delay line and a pulse generator. A new frequency detector increases the capture range up to 8% of the center frequency. We have achieved to realize the data recovery PLL that operates at DVD-ROMx14 speed.

In this paper, we propose a method to reconstruct current distributions in the human brain from neuromagnetic measurements. The proposed method is based on the weighted lead-field synthetic (WLFS) filtering technique with the weighting factors calculated from the results of previous source space scanning. In this method, in addition to the depth normalization technique, weighting factors of the WLFS are determined by the cost values previously calculated based on the multiple signal classification (MUSIC) scan. We performed computer simulations of this method under noisy measurement conditions and compared the results to those obtained with the conventional WLFS method. The results of the simulations indicate that the proposed method is effective for the reconstruction of the current distributions in the human brain using magnetoencephalographic (MEG) measurements, even if the signal-to-noise ratio of the measured data is relatively low. We applied the proposed method to the magnetoencephalographic data obtained during a mental image processing task that included object recognition and mental rotation operations. The results suggest that the proposed method can extract the neural activity in the extrastriate visual region and the parietal region. These results are in agreement with the results of previous positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) studies.

The scatterometer is a real aperture radar capable to perform a set of normalized radar cross section measurements under different azimuth angles for each resolution cell. The main field of application of a wind scatterometer regards the sea surface wind field determination. As a matter of fact, once such measurements have been performed it is possible to determine the sea surface wind field by means of an inversion procedure. In this paper we present a novel inversion scheme which is an evolution of the procedure nowday used by the Italian Space Agency (ASI) under the Italian Processing and Archiving Facility (I-PAF). A full comparative study shows that the novel inversion scheme better behaves whenever light wind regimes are in question.

We suggest the method to recover the 3D shape of an object by using a color image scanner which has three light sources. The photometric stereo is traditional to recover the surface normals of objects using multiple light sources. In this method, it usually assumes distant light sources to make the optical models simple. But the light sources in the image scanner are so close to an object that the illuminant intensity varies with the distance from the light source, therefore these light sources should be modeled as the linear light sources. In this method, by using these models and two step algorithm; the initial estimation by the iterating computation and the optimization by the non-linear least square method, not only the surface normal but also the absolute distance from the light source to the surface can be estimated. By using this method, we can recover the 3D shape more precisely. In the experimental results, the 3D shape of real objects can be recovered and the effectiveness of the proposed method is shown.

This paper presents a high resolution long array thermal ink jet (TIJ) printhead which has been developed and demonstrated to operate successfully by combining two functional Si wafers, a bubble generating heater plate fabricated using LSI process and a channel plate fabricated using Si bulk micromachining technology. The heater plate consists of logic LSIs, high voltage MOS transistor, polycrystalline Si (Poly Si) heating resistor and polyimide protective layer. The polymide layer is patterned by O2 plasma reactive ion etching (RIE) and is applicable to high resolution heater array. The Si channel plate consists of an ink chamber and an ink inlet formed by KOH etching, and a nozzle formed by inductively coupled plasma RIE (ICP RIE). The nozzle formed by RIE has squeezed structures which contribute to high energy efficiency of drop ejector and therefore successful ejection of small ink drop. These two wafers are directly bonded by using a novel electrostatic bonding of full-cured polyimide to Si. The adhesive-less bonding provided an ideal shaped small nozzle orifice. And also, the bonding method enabled to use an on-chip LSI wafer because of the contamination free material and the suitable processing conditions (low temperature). The bonded wafer is diced to form printhead chip. No delamination or displacement of the chip was observed even though the chip was subjected to thermal stress during assembly process. This is because of no difference in thermal expansion coefficient between both chips (Si and Si). And therefore it is suitable for long chip concept. With the above technologies, we have fabricated a 1.3" long printhead with 1024 nozzles having a 800 dots per inch (dpi) resolution, a 2.7 pl. ink drop volume, 14 m/sec. ink drop velocity and 18 kHz jetting frequency. And we have confirmed high speed printing and high quality printing.