Physical and optical parameters within the atmosphere-ocean system have been retrieved by a multiple scattering analysis of the reflectance and degree of linear polarization data measured by the airborne POLDER sensor in Medimar campaign in 1991. Assuming an atmosphere-ocean system with a Cox-Munk type rough sea surface model, the theoretical reflectance and -degree of linear polarization were computed by the doubling and adding method for several different models. In this study the retrieval was made by assuming a fixed refractive index of the aerosol particles, i.e., Nr=1.33-0.0i. We obtained several important results in this study as follows: 1) By comparing computed results with the observed data at 0.85m, we rejected the oceanic type aerosol model and found Junge type aerosol model with its index range of 4.0v4.5 as an appropriate model for aerosols at the observation time. 2) The reflectance data analysis in the perpendicular plane rejected an isotropic Cox-Munk model, but it indicated that an anisotropic Cox-Munk model should be used in the sea surface wind field retrieval. 3) The surface wind speed was estimated to be 10.0m/secV15.0m/sec with an best estimate of V=12.5m/sec, which agrees with the observed wind speed of V=14.4m/sec. The range of the water column reflectance was also estimated to be 0.025rwc0.045 from Medimar reflectance data at 0.45m. 4) Further study should be made for other refractive indices of the aerosol particles. More refinement of the present multiple scattering code to include upwelling polarization components from below the sea surface is also necessary.

The relative intensity noise (RIN) spectra of DC driven 1.3 µm distributed feedback laser diodes under the influence of external reflections are measured for various currents and reflection lengths. The effective power reflectivities are 310-4-310-3. The enhanced noise is observed when the relaxation oscillation frequency coincides with the external cavity frequency. It is also observed that the RIN spectra with the near end reflections differ from those with the far end reflections. The degradation of the RIN spectra is analyzed with the rate equations numerically. A new reflection noise model, which includes the carrier density change induced by the reflections, is introduced. The near and far end reflections are characterized well by this model. Furthermore, it is found that the reflection induced noise effect can be described well by the far end reflection noise model even when the reflection length is as short as 1 m.

There have been many developments on neural network research, and ability of a multi-layered network for classification of multi-spectral image data has been studied. We can classify non-Gaussian distributed data using the neural network trained by a back-propagation method (BPM) because it is independent of noise conditions. The BPM is a supervised classifier, so that we can get a high classification accuracy by using the method, so long as we can choose the good training data set. However, the multi-spectral data have many kinds of category information in a pixel because of its pixel resolution of the sensor. The data should be separated in many clusters even if they belong to a same class. Therefore, it is difficult to choose the good training data set which extract the characteristics of the class. Up to now, the researchers have chosen the training data set by random sampling from the input data. To overcome the problem, a hybrid pattern classification system using BPM and Kohonens feature mapping (KFM) has been proposed recently. The system performed choosing the training data set from the result of rough classification using KFM. However, how the remotely sensed data had been influenced by the KFM has not been demonstrated quantitatively. In this paper, we propose a new approach using the competitive weight vectors as the training data set, because we consider that a competitive unit represents a small cluster of the input patterns. The approach makes the training data set choice work easier than the usual one, because the KFM can automatically self-organize a topological relation among the target image patterns on a competitive plane. We demonstrate that the representative of the competitive units by principal component analysis (PCA). We also illustrate that the approach improves the classification accuracy by applying it on the classification of the real remotely sensed data.

With the fully depleted ultra-thin-film SOI CMOS, one important issue is controlling the threshold voltage (Vth) while maintaining high speed operation and low power consumption. To control the Vth, applying a bias voltage to the substrate is one of the most practical methods. We suggest a fully depleted ultra-thin-film SOI CMOS with a floating back gate, which is formed at the lower part of the channel field inside the substrate and stores electrons injected into it. This device can eliminate the necessity of an extra circuit or a separate power supply to apply a negative voltage. The silicon wafer direct bonding technique is used to construct this device. With the prototyped devices, we can successfully control the Vth for both the nMOSFET and pMOSFET at around 0.5 V by controlling the quantity of the electric charges injected into the floating back gate.

The ultraclean sputtering process (UC-process) was newly introduced in the fabrication of Co62.5Ni30Cr7.5 and Co85.5Cr10.5Ta4 thin film media to establish a new concept in controlling microstructure. UC-process enables the realization of high coercive force Hc up to 2.7-3 kOe in both CoNiCr and CoCrTa media (15/50 nm magnetic/Cr thicknesses) without the decrement of saturation magnetization. The purification of the atmosphere during sputtering and the removal of the adsorbed oxygen impurity on the substrate surface play important roles in obtaining high Hc by applying the UC-process. This high Hc is mainly due to the realization of large magnetocrystalline anisotropy field of grains Hkgrain and low intergranular exchange coupling. UC-process realizes the adequate separation of grains by segregated grain boundaries even in media with thin Cr thickness of 2.5 nm, and enables grain size reduction without the remarkable increment in intergranular exchange coupling. In these media, the reduction of the grain size is most effective for the improvement of readback signal to media noise ratio S/Nm. In the media with grains sufficiently separated by segregated grain boundaries fabricated by the UC-process, control of grain size reduction and further increase in Hc/Hkgrain value through the decrement in intergranular magnetostatic coupling are required to obtain higher S/Nm value.

In this paper, electromagnetic scattering by infinite double two-dimensional periodic array of resistive upper and lower elements is considered. The electric field equations are solved by using the moment method in the spectral domain. Some numerical results are shown and frequency selective properties are discussed.

In this paper, an analysis of a slotted ring type network, the Pierce type ring network, is carried out and characteristics of the ring are derived. The ring type network is one of the fundamental computer network topologies. It is easy to implement and has many merits such as low cost and expansion flexibility. However, possible hogging, or domination of slots by one station, is one of its drawbacks. At first, when we regard vacant slots as usable, we show how system performance is fairly dependent on traffic patterns. We also show quantitatively that when slots are fixed to each station, domination of the ring can be completely prevented, although the performance of the system will be reduced. We propose a method to control the transmission of packets in which we have positively adopted the insertion of shift registers into the transmission line to prevent the deterioration of the performance. With the insertion of shift registers, we show the feasibility of improving the performance of the fixed slot allocation method at the same time as preventing domination of the ring. We will discuss the merits of the shift register insertion method, which is introduced to improve the fixed slot and semi-fixed slot allocation methods. In the slotted ring type system, four types of slot allocation method including a register insertion method are considered for the improvement of the system performance. The merits and demerits of the methods are discussed. We show how system performance depends on the traffic patterns considered. We analyse the characteristics of the ring system under various conditions.

An interactive painting system for generating calligraphy words is developed. Its significant advantage lies in effective rendering functions that synthesize kasure and nijimi textures due to the effects of brush and absorbent painting paper. The system enables users to generate high quality and realistic calligraphy words.

Signal processing antennas have been studied not only for interference suppression but also for high-resolution estimation of radio environment such as directions-of-arrival of incident signals. These two applications are based on the common technique, that is, null steering. This tutorial paper reviews the MUSIC algorithm which is one of the typical high-resolution techniques. Examining the eigenvector beam patterns, we demonstrate that the high-resolution capability is realized by steering nulls. The considerations will be useful for understanding the high-resolution techniques in the signal processing antennas. We then describe a modified version of MUSIC (Root MUSIC). We show the performance and robustness of the method. Furthermore, we introduce radar target identification and two-dimensional radar target imaging. These study fields are new applications of the signal processing antennas, to which a great deal of attention has been devoted recently.

To evaluate the radial eigenmode field distributions and the resonance wavelengths of axially symmetric pillbox resonator, a numerical method is described which is based on the FE-BPM expression in cylindrical coordinates. Under the weakly guiding approximation, we solve Fresnel equation and can get a fairly accurate result. By using effective index method, 3-D pillbox guiding structure is reduced to 2-D one which is then used for the analysis. One advantage of this method is that it is applicable for the axially symmetric optical waveguides with arbitrary index distribution. The validity of this method is checked by comparing the results of this method with those of the analytical ones. This method is applied for the evaluation of the coupling properties of a coupled structure consisting of a pillbox resonator and a curved waveguide placed outside the pillbox. This coupled structure has a good prospect to be used as optical wavelength filter. By varying the separation distance between the pillbox and the outer curved waveguide, the power transfer due to coupling is determined near the resonance wavelength 0.9 µm.

Ba ferrite films were deposited epitaxially on ZnO underlayer from targets with composition of BaO-6.5Fe2O3 at substrate temperature of 600 using the facing targets sputtering apparatus. The gas mixture of Ar and Xe of 0.18 Pa and O2 of 0.02 Pa was used as the sputtering gas and the dependences of crystallographic and magnetic characteristics on the partial Xe pressure PXe(0.0-0.18 Pa) were investigated. Films deposited at various PXe were composed of BaM ferrite and spinel crystallites, and the minimum centerline average roughness Ra of 8.3 nm was obtained at PXe of 0.10 Pa. Since saturation 4πMs of 5.1 kG and perpendicular anisotropy constant Ku1 of 4.23105 Jm-3 were larger than those of bulk BaM ferrite of 4.8 kG and 3.30105 Jm-3, respectively, these films appeared promising for use as perpendicular recording media.

Co-Zr and Co-Zr-Ta amorphous films were prepared by the Kr sputtering method for use as the backlayers of Co-Cr perpendicular magnetic recording tape media. The effect of the addition of Ta to Co-Zr thin films was also investigated. Lower substrate temperature was required to prepare amorphous Co-Zr films with excellent soft magnetic properties. The relationships among Ta content X, magnetostriction constant λ and magnetic characteristics such as coercivity Hc and relative permeability µr were clarified. A method of evaluating λ of soft magnetic thin films deposited on polymer sheet substrate has been presented. Films with composition of (Co95.7Zr4.3) 100-X TaX at X of 10 at.% possessed sufficiency soft magnetic properties such as low Hc below 80 A/m and high µr above 600. Addition of Ta was effective in changing change the sign of λ from positive to negative. It was found that the negative magnetoelastic energy and the smaller λ caused the soft magnetism.

A graph G = (V, E) with N nodes is called an N-hyper-ring if V = {0, ..., N-1} and E = {(u, v)(u-v) modulo N is power of 2}. We study embeddings of the 2n-hyper-ring in the n-dimensional hypercube. We first show a greedy embedding with dilation 2 and congestion n+1. We next modify the greedy embedding, and then we obtain an embedding with dilation 4 and congestion 6.

A new method is developed to generate fuzzy rules from numerical data. This method consists of two algorithms: Algorithm 1 is used to identify structures of the given data set, that is, the optimal number of rules of system; Algorithm 2 is used to identify parameter of the used model. The former is belonged to unsupervised learning, and the latter is belonged to supervised learning. To identify parameters of fuzzy model, we developed a neural network which is referred to as Unsymmetrical Gaussian Function Network (UGFN). Unlike traditional fuzzy modelling methods, in the present method, a) the optimal number of rules (clusters) is determinde by input-output data pairs rather than by only output data as in sugeno's method, b) parameter identification of ghe present model is based on a like-RBF network rather than backpropagation algorithm. Our method is simple and effective because it integrates fuzzy logic with neural networks from basic network principles to neural architecture, thereby establishing an unifying framework for different fuzzy modelling methods such as one with cluster analysis or neural networks and so on.

A folded short in parallel-plate waveguide is investigated using the Fourier transform and the mode-matching. A fast-converging series solution for scattering from the folded short is obtained and its characteristics are presented. Our solution for the E-plane short agrees well with measurements and is numerically more efficient than the existing moment-method solution. The presented scattering characteristics are useful for the design of the E- and H -plane shorts in rectangular waveguide.

The radiation and scattering characteristics of a metal-strip grating of finite extent printed on the surface of a dielectric waveguide are analyzed within a two-dimensional model. The diffraction properties are obtained from a solution to the problem of surface mode scattering by a finite number of metal strips, taking into account their mutual couplings. The analysis is based on the electromotive force technique which does not require a grating to be periodic. Obtained results concern the antenna applications of radiating gratings excited by the dominant TE or TM surface mode of the wavegude. The proposed approach can be applied not only to the design of radiators but also filters based on periodic strip gratings.

Coherent and incoherent electromagnetic (EM) waves scattered by many particles are approximately expressed as solutions of integral equations by unconventional multiple scattering method. The particles are randomly displaced from a uniformly ordered distribution, and hence the distribution of particles can change from total uniformity to complete randomness. The approximate expressions of the EM waves are systematically given, independent of the distributions of particles, on the following assumptions. First the particles are identical in material, shape, size and orientation. Second each random displacement of particles from the ordered positions is statistically independent of each other and homogeneous in space. These assumptions may be extended to more general ones but have been used here to make clear the derivation process of the coherent and incoherent EM waves. The approximate expressions of the EM waves are reduced to known ones for both limiting cases: a periodic distribution and a very sparse random distribution. The effective dielectric constant of a random medium containing randomly distributed dielectric spheres can be calculated from the coherent EM wave and compared with those given by conventional methods such as the quasi-crystalline approximation, using the previous results. The comparison indicates the advantage of the method presented here. The present method is expected to be useful for the study of interaction of EM waves with many particles.

A numerical scheme to analyze a three-dimensional perfectly conducting body that has edges and corners is presented. The geometry of the body can be arbitrary. A new formulation using boundary element method has been developed. This formulation allows that a scatterer has edges and corners, where the behavior of the electromagnetic fields become singular.

Information capture is a very desirable and important function in portable computers. The "Multimedia Notebook" is a portable tool for capturing information in multimedia format, which includes photos, voice, and handwritten memos. Recent portable units, sometimes called PDA (Personal Digital Assistants) or Communicators, have PIM (Personal Information Manager) software and some communication facility. Their purpose is to enlarge the desktop environment to follow the user outside the office. This is one application of portable equipment, however we felt that hand-held equipment can also be used for more general information capture. In the past, information capture was limited, because people had to carry bulky equipment to the information source. Recent portable computers that have the capability to handle still and motion pictures, voice, and handwritten drawings allow the implementation of more information capture capabilities. Capture of handwritten notes has already been implemented on portable equipment like PDAs. However, this application doesn't make the most of its potential. We feel that the Multimedia Notebook should integrate handwritten memos with pictures and voice. The advantage is that users can capture what they watch and hear easily in a variety of media for later review. The information in each medium complements the others. When arranging the recorded information, it is easy to use each medium efficiently. We have examined the human interface and designed it for user-friendliness and to be comparable to pen and paper. The prototypes also have a capture buffer which can operate continuously to capture voice and pictures that would otherwise be lost because of the user's delay in starting to record.

This paper proposes a new algorithm called the fast Projection algorithm, which reduces the computational complexity of the Projection algorithm from (p+1)L+O(p3) to 2L+20p (where L is the length of the estimation filter and p is the projection order.) This algorithm has properties that lie between those of NLMS and RLS, i.e. less computational complexity than RLS but much faster convergence than NLMS for input signals like speech. The reduction of computation consists of two parts. One concerns calculating the pre-filtering vector which originally took O(p3) operations. Our new algorithm computes the pre-filtering vector recursively with about 15p operations. The other reduction is accomplished by introducing an approximation vector of the estimation filter. Experimental results for speech input show that the convergence speed of the Projection algorithm approaches that of RLS as the projection order increases with only a slight extra calculation complexity beyond that of NLMS, which indicates the efficiency of the proposed fast Projection algorithm.