Medium noise is the dominant noise in ultrahigh density disk recording systems. The peak, width and jitter noise are analyzed by micromagnetic simulations. Four different media, with a fixed grain size of 135 and a coercivity of 2900 Oe, are chosen for medium noise analysis. The linear recording density is increased from 340 KFCI (Kilo flux-changes per inch) to 750 KFCI, while the area density goes up from 14.3 Gb/in2 to 31.5 Gb/in2. The peak-amplitude noise is studied by the distribution of the peak magnetization Mp in each bit. The distribution of Mp develops from a delta-function around the remanence Mr at low densities to a flat distribution at extremely high densities. It is found that the transition a-parameter is no longer proportional to the square root of Mrδ, as given in the William-Comstock approximation. The peak-jitter noise in the read back voltage is analyzed by the percentage of the transition jitter in a bit length.

An optimization of the smoothing preprocessing for the correlated signal parameter estimation was considered. Although the smoothing factor (the number of subarrays) is a free parameter in the smoothing preprocessing, a useful strategy to determine it has not yet been established. In this paper, we investigated thoroughly about the smoothing factor and also proposed a new scheme to optimize it. The proposed method, using the smoothed equivalent diversity profile (SED profile), is able to evaluate the effect of smoothing preprocessing without any a priori information. Therefore, this method is applicable in the real multipath parameter estimation.

Fourier analysis of sinusoidal and/or quasi-periodic signals in additive noise has been used in various fields. So far, many analysis algorithms including the well-known DFT have been developed. In particular, many adaptive algorithms have been proposed to handle non-stationary signals whose discrete Fourier coefficients (DFCs) are time-varying. Notch Fourier Transform (NFT) and Constrained Notch Fourier Transform(CNFT) proposed by Tadokoro et al. and Kilani et al., respectively, are two of them, which are implemented by filter banks and estimate the DFCs via simple sliding algorithms of their own. This paper presents, for the first time, statistical performance analyses of the NFT and the CNFT. Estimation biases and mean square errors (MSEs) of their sliding algorithms will be derived in closed form. As a result, it is revealed that both algorithms are unbiased, and their estimation MSEs are related to the signal frequencies, the additive noise variance and orders of comb filters used in their filter banks. Extensive simulations are performed to confirm the analytical findings.

Magnetoencephalography (MEG) is a powerful and non-invasive technique for measuring human brain activity with a high temporal resolution. The motivation for studying MEG data analysis is to extract the essential features from measured data and represent them corresponding to the human brain functions. In this paper, a novel MEG data analysis method based on independent component analysis (ICA) approach with pre-processing and post-processing multistage procedures is proposed. Moreover, several kinds of ICA algorithms are investigated for analyzing MEG single-trial data which is recorded in the experiment of phantom. The analyzed results are presented to illustrate the effectiveness and high performance both in source decomposition by ICA approaches and source localization by equivalent current dipoles fitting method.

This paper investigates the modeling of non-linearity on the generation of the single trial evoked potential signal (s-EP) by means of using a mixed radial basis function neural network (M-RBFN). The more emphasis is put on the contribution of spontaneous EEG term to s-EP signal. The method is based on a nonlinear M-RBFN neural network model that is trained simultaneously with the different segments of EEG/EP data. Then, the output of the trained model (estimator) is a both fitted and reduced (optimized) nonlinear model and then provide a global representation of the passage dynamics between spontaneous brain activity and poststimulus periods. The performance of the proposed neural network method is evaluated using a realistic simulation and applied to a real EEG/EP measurement.

It is known that amorphous continuous media such as TbFeCo have extremely low noise characteristics because of the structure of the continuous grainless medium. There is great interest in the use of amorphous media in magnetic recording. This study investigated the recording characteristics of the amorphous continuous medium by computer simulation using the Landau-Lifshitz-Gilbert equation. It was shown that the transition of the continuous medium is very sharp and the noise level very low. It was also shown that the recorded magnetization patterns of the continuous medium are distinct at the high recording density of 380 Gbit/inch2. We concluded that the continuous medium has great potential for use in ultra-high density recording.

Post annealing treatment for CoCrPt magnetic thin films were tried in different thermal conditions, by changing the time of annealing procedure. Coercivity (Hc) improvement was achieved in annealed sample compared with those as deposited, in which as high as 5.2 kOe has been attained. To clarify the mechanism of annealing treatment on the magnetic properties, X-ray diffraction (XRD) spectrums of those samples and their magnetic properties were carefully studied. Co and Cr lattice parameters were separately calculated from different crystal lattice plane. It was found that a axis lattice spacing of Co hexagonal structure increases monotonically with increased annealing time. Variation of Co hcp peaks significance may due to Cr or Pt redistribution in the crystal grains and its boundaries. Combined with the grain size analysis of Co-rich area by X-ray diffraction peak broaden width, which was not very consistent with the result obtained from other's TEM and AFM studies, Cr diffusion was suggested to be the governing factor at short annealing time region. Co-rich grain growth should also be applied to explain the variation of magnetic properties in longer post annealing.

SiO2-added Ba ferrite (BaM:SiO2) films were prepared using BaFe12Si0.18Ox targets. BaM:SiO2 films exhibited perpendicular coercivity Hc⊥ of over 4.2 kOe and squareness ratio of 0.83, although saturation magnetization Ms decreased by about 15%. The angular dependence of coercivity Hc and remanent coercivity Hr were investigated to explain the magnetization reversal mechanism. Intergranular interactions in the films were also evaluated. The magnetization reversal mode of Ba ferrite films with and without SiO2 additives is not coherent rotation but appears to be the curling mode. The origin of the high coercivity of BaM:SiO2 films is different from that of Al-substituted Ba ferrite films. It seemed that SiO2 additives and the defects caused by them decreased Ms and prevented the expansion of reversed domains in the magnetization reversal process, similarly to some pinning effects, and caused high Hc⊥ of 4.2-5.1 kOe in BaM:SiO2 films.

An electronic model of the coronary vessel consisting of resistor, capacitor and Field Effect Transistor (FET) is proposed in order to perform a dynamic simulation of the left coronary circulation and to clarify its mechanisms. Based on this model, an equivalent circuit of the coronary circulation is constructed that is divided into subepicardial and subendocardial layers and consists of segments of artery, arteriole, capillary, venule and vein for both the layers. In this simulation, the observed flow waveform of the left main artery showed dominance of flow in diastole as compared to that in systole. In epicardium, inverse venous flow was observed in early systole. These simulated waveforms are similar to those in real left coronary circulation observed by physiological and clinical researchers. Among all the segments of intramyocardium, only the venules were found to possess a time-varying resistance characteristics. From the results of this study, it is considered that the combination of resistance and capacitance of the vessel acts as an integrator and a differentiator for blood pressure and intramyocardial pressure, respectively and that the effects of integration of blood pressure and differentiation of intramyocardial pressure play a very important role in determining the factors influencing the left coronary circulation.

In this paper, the improvement technique for a nonlinear parallel interference cancellation (PIC) receiver for a DS-CDMA system is studied, which cancels only the estimated multiple access interference (MAI) from specific users at each receiver stage. This technique was introduced as a PIC receiver using null zone hard decision in the proceeding of IEEE MILCOM '94, but the numerical results has not been fully provided with varying decision threshold. In this paper, the performance of the PIC receiver using null zone hard decision is shown in a Rayleigh fading channel. Also, a new PIC receiver with an adaptive decision threshold is proposed. In the proposed new PIC receiver, the decision threshold for partial cancellation is adjusted according to the statistic of its matched filter (MF) outputs. The BER of the proposed PIC receiver is obtained by simulation and compared with those of the conventional PIC receiver and the PIC receiver using null zone hard decision in a Rayleigh fading channel. It is shown that the proposed PIC receiver achieves better performance than the conventional PIC receiver and the PIC receiver using null zone hard decision in a Rayleigh fading channel.

This paper reports the implementation in three dimensions (3D) of diffusion models for low dose implanted dopants in silicon and the various numerical issues associated with it. In order to allow the end-users to choose between high accuracy or small calculation time, a conventional and 5-species diffusion models have been implemented in the 3D module DIFOX-3D belonging to the PROMPT plateform. By comparison with one and two-dimensional (1D and 2D) simulations performed with IMPACT-4, where calibrated models exist, the validity of this 3D models have been checked. Finally, the results obtained for a 3-dimensional simulation of a rapid thermal annealing step involved in the manufacturing of a MOS transistor are presented what show the capability of this module to handle the optimization of real devices.

This paper presents a new technique for the synthesis of orthogonal-base-set sequences suitable for applications requiring sets of uncorrelated pseudo-white-noise sources. The synthesized sequences (vectors) are orthogonal to each other, and each sequence also has a flat power spectrum and low peak factor. In order to construct the orthogonal-base-set sequences, the new application of ta-sequence (trigonometric function aliasing sequence) introduced in this paper uses Latin-squares and Walsh-Hadamard sequences. The ta-sequence itself is a very new concept, and the method presented here provides the means for generating various orthogonal-base-set sequences at sizes required for such applications as system measurement (needing uncorrelated test signals), pseudo noise synthesis for spread spectrum communication, and audio signal processing (needing synthesis of stereo or multichannel signals from mono sources).

The high accuracy which is necessary for modern process simulation often requires the use of Monte-Carlo ion implantation simulation methods with the disadvantage of very long simulation times especially for three-dimensional applications. In this work a new method for an accurate and CPU time efficient three-dimensional simulation of ion implantation is suggested. The approach is based on a combination of the algorithmic capabilities of a fast analytical and the Monte-Carlo simulation method.

We examine the detection of coded hybrid direct-sequence frequency-hopped spread-spectrum signals in the presence of narrowband interference. Since blind interference suppression requires a reliable estimate of the data, while at the same time data decoding requires interference suppression, we advocate an iterative ("turbo") detection scheme whereby information is exchanged between the interference suppressor and the soft-input soft-output decoder. Several suppression schemes are examined and compared. Simulation results show that this new scheme is robust, i.e., exhibits good performance under a modicum of assumptions on the interference structure. Turbo codes and convolutional codes are compared, showing that the former perform better.

This paper proposes higher-order spread spectrum direct optical switching CDMA system and an aliasing canceler to remove the aliasing distortion caused by higher-order bandpass sampling. Theoretical analysis of the signal quality shows that the 3rd order bandpass sampling scheme can improve the carrier-to-interference-power ratio compared with the conventional 1st order bandpass sampling scheme, by 5 dB.

In this paper the application of a linear-quadratic processor is proposed for detection of each user's signal in a direct sequence code division multiple access scheme and, in particular, for W-CDMA systems. In this method, the knowledge of the user of interest, and some statistical knowledge of interfering transmitters' signals are used to detect the desired user's signal without needing exact "a priori" knowledge of the interfering signal parameters such as spreading sequences and signal powers. Parameters of the proposed processor, which are derived so as to maximise the signal-to-interference-plus-noise ratio (SINR), can generally be obtained by solving a system of linear equations for which many effective techniques exist. A model for this detection procedure is developed and shown--through analytical and numerical results--to offer a good compromise between complexity and quality of performance.

A circuit-level electrothermal simulator, MICS (MItsubishi Circuit Simulator), is presented with parasitic bipolar transistor action and lattice heating taken into account. Diffusion capacitance in parasitic bipolar transistors is introduced to cover turn-on behavior under short rise-time current. Device temperatures are simulated from calculated electrical characteristics and the closed-form solution of the heat transfer equation. Simulation results show that this tool is valuable in evaluating electrostatic discharge (ESD) robustness in integrated circuits (ICs).

This work presents the first comprehensive full-band Monte Carlo model for the simulation of silicon/silicon-germanium devices with arbitrary germanium profiles. The model includes a new CPU and memory efficient method for the discretization of the Brillouin zone based on adaptive nonuniform tetrahedral grids and a very efficient method for transfers through heterointerfaces in the case of irregular -space grids. The feasibility of the FB-MC simulation is demonstrated by application to an industrial HBT with a graded germanium profile and different aspects of the microscopic carrier transport are discussed. Internal distributions of the transistor are calculated with a very low noise level and high efficiency allowing a detailed investigation of the device behavior.

This paper reports a Monte Carlo calculation of the bimolecular reaction of arsenic precipitation. As the accuracy of the numerical solution for the coupled rate equations strongly depends on the size of grid spacing, it is necessary to choose adequate number of rate equations in order to understand the behavior of the extended defects. Therefore, we developed a general kinetic Monte Carlo model for the extended defects, which explicitly takes the time evolution of the size density of the extended defects into account. The Monte Carlo calculation exhibits a quantitative agreement with the experimental data for deactivation, and successfully reproduces the rapid deactivation at the beginning phase followed by slow deactivation in the subsequent steps.

In this letter, we remark a well-known nonlinear filtering technique realize immediate effect to suppress the influence of the additive measurement noise in the input to a set theoretic linear blind deconvolution scheme. Numerical examples show ε-separating nonlinear pre-filtering techniques work suitably to this noisy blind deconvolution problem.