Most of the image restoration filters proposed so far include parameters that control the restoration properties. For bringing out the optimal restoration performance, these parameters should be determined so as to minimize a certain error measure such as the mean squared error (MSE) between the restored image and original image. However, this is not generally possible since the unknown original image itself is required for evaluating MSE. In this paper, we derive an estimator of MSE called the subspace information criterion (SIC), and propose determining the parameter values so that SIC is minimized. For any linear filter, SIC gives an unbiased estimate of the expected MSE over the noise. Therefore, the proposed method is valid for any linear filter. Computer simulations with the moving-average filter demonstrate that SIC gives a very accurate estimate of MSE in various situations, and the proposed procedure actually gives the optimal parameter values that minimize MSE.

The present paper describes the finite difference time domain (FDTD) analysis of the light-beam diffraction from two- and three-dimensional (2-D and 3-D) magneto-optical (MO) disk structures. First, we show that the proposed new FDTD formulation is valid for MO disk medium and can avoid the divergence of fields encountered during the conventional FDTD calculations. Second, as the application of the present method to more complicated models, the main- and cross-polarized diffracted fields are numerically calculated for 2-D and 3-D four-layered MO disk models. The phase differences between two kinds of polarized components are shown. The results obtained here indicate that the proposed FDTD formulation can be applied to more complicated MO disk structures.

A password-based mechanism is the most widely used method of authentication in distributed environments. However, because people are used to choosing easy-to-remember passwords, so-called "weak-passwords," dictionary attacks on them can succeed. The techniques used to prevent dictionary attacks lead to a heavy computational load. Indeed, forcing people to use well-chosen passwords, so-called "strong passwords," with the assistance of tamper-resistant hardware devices can be regarded as another fine authentication solution. In this paper, we examine a recent solution, the SAS protocol, and demonstrate that it is vulnerable to replay and denial of service attacks. We also propose an Optimal Strong-Password Authentication (OSPA) protocol that is secure against stolen-verifier, replay, and denial of service attacks, and minimizes computation, storage, and transmission overheads.

We propose hysteresis neural network solving combinatorial optimization problems, Box Puzzling Problem. Hysteresis neural network searches solutions of the problem with nonlinear dynamics. The output vector becomes stable only when it corresponds with a solution. This system does never become stable without satisfying constraints of the problem. After estimating hardware calculating time, we obtain that numerical calculating time increases extremely comparing with hardware time as problem's scale increases. However the system has possibility of limit cycle. Though it is very hard to remove limit cycle completely, we propose some methods to remove this phenomenon.

This work presents a novel description of texture mapping polygons in a geometric view about scanlines and a simplified mapping function to improve the performance. The conventional perspective-correct mapping requires costly division operations. In this work, two concepts in perspective geometry, cross-ratio and vanishing point, are exploited to simplify the mapping function. We substitute the point at infinity on scanline into the cross-ratio equation, then obtain a simple description of perspective mapping in polygons. Our mapping function allows the spatial mapping of a pixel from a scanline on a screen plane to a texture plane taking only one division, one multiplication and three additions. The proposed algorithm speeds up the mapping process without losing any correctness. Experimental results indicate that the performance of proposed method is superior to other correct mapping methods.

Magnetic tunnel junctions (MTJ), i.e., structures consisting of two ferromagnetic layers (FM1 and FM2), separated by a very thin insulator barrier (I), have recently attracted attention for their large tunneling magnetoresistance (TMR) which appears when the magnetization of the ferromagnets of FM1 and FM2 changes their relative orientation from parallel to antiparallel in an applied magnetic field. Using an ultrahigh vacuum magnetron sputtering system, a variety of MTJ structures have been explored. Double Hc magnetic tunnel junction, NiFe/Al2O3/Co and FeCo/Al2O3/Co, were fabricated directly using placement of successive contact mask. The tunnel barrier was prepared by in situ plasma oxidation of thin Al layers sputter deposited. For NiFe/Al2O3/Co junctions, the maximum TMR value reaches 5.0% at room temperature, the switching field can be less than 10 Oe and the relative step width is about 30 Oe. The junction resistance changes from hundreds of ohms to hundreds of kilo-ohms and TMR values decrease monotonously with the increase of applied junction voltage bias. For FeCo/Al2O3/Co junctions, TMR values exceeding 7% were obtained at room temperature. It is surprising that an inverse TMR of 4% was observed in FeCo/Al2O3/Co. The physics governing the spin polarization of tunneling electrons remains unclear. Structures, NiFe/FeMn/NiFe/Al2O3/NiFe, in which one of the FM layers is exchange biased with an antiferromagnetic FeMn layer, were also prepared by patterning using optical lithography techniques. Thus, the junctions exhibit two well-defined magnetic states in which the FM layers are either parallel or antiparallel to one another. TMR values of 16% at room temperature were obtained. The switching field is less than 10 Oe and step width is larger than 30 Oe.

We derive an efficient and simple analytical expression for estimating maximum simultaneous switching noise (SSN) on ground distribution networks in CMOS systems. In order to estimate maximum SSN voltages, we use α-power law MOS model and Taylor's series approximation. The accuracy of the proposed expression is verified by comparing the results with those of previous researches and HSPICE simulations under the contemporary process parameters and environmental conditions. The proposed method predicts the maximum SSN values more accurately when compared to existing approaches even in most practical cases such that there exist some output drivers not in transition.

This paper shows a comparison between several procedures to represent the Physical Optics (PO) current density into a hybrid Moment-Method-Physical-Optics (MM-PO) code. Some numerical results demonstrate that a set of basis functions suitable for the Method of Moments (MM) may be inappropriate to model the PO currents. A new evaluation of the PO operator is proposed. The radiation can be analytically determined and, since it includes a linear interpolation of the phase, it can be applied over large triangular domains. This allows a drastic reduction of the computational cost, maintaining or even improving the level of accuracy.

Employing reactive sputtering using an electron-cyclotron-resonance microwave plasma without oxidation process, high coercivity ferrite thin-films with perpendicular magnetic anisotropy were successfully prepared without NiO underlayer at low substrate temperature. The ferrite thin-film deposited on glass substrate had smooth surface and were composed of small grains. Perpendicular recording was performed on the ferrite thin-film hard disk. The ferrite thin-films with high coercivity could be prepared on flexible film substrates (Polyimide and PET).

The current voltage characteristics of the ballistic metal oxide semiconductor field effect transistor (MOSFET) is reviewed. Reducing the carrier scattering by employing e.g. the intrinsic channel structure and the low temperature operation, nanometer to sub-0.1 µm size MOSFETs operation approaches the ballistic transport. The drain current is derived by analyzing the carrier behavior in the vicinity of the potential maximum in the channel. The carrier degeneracy and the predominant carrier distribution in the lowest subband around the maximum point have critical effects on the current value. A convenient approximation of the current in terms of terminal voltages is given. The current control mechanism is discussed with use of the "Injection velocity," with which carriers are injected from the source to the channel. An index to represent the ballisticity is given, and some published experimental data are analyzed. Transport of the quasi-ballistic MOSFET is discussed.

This paper presents a DFT controller called as a TCU (Test Control Unit), which considerably improves the efficiency of the instruction-based functional test. Internal program/data buses are completely controllable and observable by the TCU during the test cycle. Diverse test modes of the TCU can increase the test efficiency and also provide complete access to program/data memories for functional test.

In this paper, we explore the possibility of applying associative memories for locating frontal views of human faces in complex scenes. An appealing property of the associative-memory-based face detection system is that learning of the associative memory may be achieved by using a simple Hebbian learning rule. In addition, a simple heuristic rule is used to quickly filter a certain amount of nonface images at the very beginning of the whole detection procedure. By using the rule, we won't waste unnecessary computational resources on those nonface images. A database consisting of 74 images was used to test the performance of our associative-memory-based human face detection system.

We believe the quantum functional device to be a future perspective device, if we solve the problems that it has nowadays. We will summarize such problems with several discussions from the viewpoint of circuit and system.

In the more general framework "shift invariant subspace," the paper obtains a different estimate of sampling in function subspace to our former work, by using the Frame Theory. The derived formula is easy to be calculated, and the estimate is relaxed in some shift invariant subspaces. The former work is now, however, a special case of the present.

As a method of analyzing the wave scattering from a finite periodic surface, this paper introduces a periodic approach. The approach first considers the wave diffraction by a periodic surface that is a superposition of surface profiles generated by displacing the finite periodic surface by every integer multiple of the period . It is pointed out that the Floquet solution for such a periodic case becomes an integral representation of the scattered field from the finite periodic surface when the period goes to infinity. A mathematical relation estimating the scattering amplitude for the finite periodic surface from the diffraction amplitude for the periodic surface is proposed. From some numerical examples, it is concluded that the scattering cross section for the finite periodic surface can be well estimated from the diffraction amplitude for a sufficiently large .

In this article, we survey current and next generation IX (Internet eXchange) technologies. An IX is a mechanism to interconnect many networks to each other. In other words, an ISP can establish 'peerings' with other ISPs by connecting their routers into IXes. First, we describe the basic IX model, including a policy model, called the 'bilateral' model, which allows participating ISPs to control routing policy and traffic on a 'peer' basis. Next, we classify current IX architectures from a technical point of view and discuss issues of current IXes. In the latter potion of this article, we describe next generation IX technologies, which achieve new features for IXes, such as: enabling larger volume traffic exchange with optical technology, providing virtual private peerings, migrating data-link media to participate into an IX, and exchanging traffic over widely distributed areas. We survey cutting-edge technologies for next generation IXes, and discuss the future of IX technology.

The diverse broadcast means that will be available in the future will cause an increased demand for programs. When the input of the posture of an agent is used to manipulate a virtual computer graphics actor, it is better if the system does not require a special studio and devices. In the present paper, we propose a way to extract images from a single picture based on estimates of blooming. This is done using a partial auto-correlation analysis that carries out backward and forward predictions simultaneously. And, we divide targets into the stratified depth from a single image. An experiment was conducted using a picture taken with a digital camera, and satisfactory results were obtained.

A halftoning technique that uses a simple GA has proven to be very effective to generate high quality halftone images. Recently, the two major drawbacks of this conventional halftoning technique with GAs, i.e. it uses a substantial amount of computer memory and processing time, have been overcome by using an improved GA (GA-SRM) that applies genetic operators in parallel putting them in a cooperative-competitive stand with each other. The halftoning problem is a true multiobjective optimization problem. However, so far, the GA based halftoning techniques have treated the problem as a single objective optimization problem. In this work, the improved GA-SRM is extended to a multiobjective optimization GA to simultaneously generate halftone images with various combinations of gray level precision and spatial resolution. Simulation results verify that the proposed scheme can effectively generate several high quality images simultaneously in a single run reducing even further the overall processing time.

In this paper, we deal with the problem of compatibility class encoding, and propose a novel algorithm for finding a good functional decomposition with application to LUT-based FPGA synthesis. Based on exploration of the design space, we concentrate on extracting a set of components, which can be merged into the minimum number of multiple-output CLBs or LUTs, such that the decomposition constructed from these components is also minimal. In particular, to explore more degrees of freedom, we introduce pliable encoding to take over the conventional rigid encoding when it fails to find a satisfactory decomposition by rigid encoding. Experimental results on a large set of MCNC91 logic synthesis benchmarks show that our method is quite promising.

This paper presents a digital reaction-diffusion system (DRDS)--a model of a discrete-time discrete-space reaction-diffusion dynamical system--for designing new image processing algorithms inspired by biological pattern formation phenomena. The original idea is based on the Turing's model of pattern formation which is widely known in mathematical biology. We first show that the Turing's morphogenesis can be understood by analyzing the pattern forming property of the DRDS within the framework of multidimensional digital signal processing theory. This paper also describes the design of an adaptive DRDS for image processing tasks, such as enhancement and restoration of fingerprint images.