An idea of optimal output permutation of multiple-valued sum-of-products expressions is presented. The sum-of-products involve the TSUM operator on the MIN of window literal functions. Some bounds on the maximum number of implicants needed to cover an output permuted function are clarified. One-variable output permuted functions require at most p1 implicants in their minimal sum-of-products expressions, where p is the radix. Two-variable functions with radix between three and six are analyzed. Some speculations of maximum number of the implicants could be established for functions with higher radix and more than 2-variables. The result of computer simulation shows that we can have a saving of approximately 15% on the average using permuting output values. Moreover, we demonstrate the output permutation based on the output density as a simpler method. For the permutation, some speculation is shown and the computer simulation shows a saving of approximately 10% on the average.

This paper presents Bi-CMOS current-mode multiple valued logic circuit with 1.5 V supply voltage. This circuit is composed of current mirror, threshold detector and current source. This circuit has advantages such as high accuracy, high speed, high density and low supply voltage. So, it is possible to realize high-radix multiple valued logic circuit. As an other application of the proposed circuit, a processing unit of fuzzy inference is given. This circuit operates with high speed and high accuracy. The circuit simulation of the proposed circuit has been performed using SPICE2 program.

We describe an approach to describe moving pictures in terms of their structural properties for video editing, video indexing, and video coding. The description contains 2D shape, motion, spatial relation, and relative depth of each region. To obtain the description, we develop the incremental segmentation scheme which includes dynamic occlusion analysis to determine relative depths of several objects. The scheme has been designed along the analysis-by-synthesis" approach, and uses a sequence of images to estimate object boundaries and motion information successively/incrementally. The scheme consists of three components: motion estimation, prediction with dynamic occlusion analysis, and update of the segmentation results. By combining the information from extended (longer) image sequences, and also by treating the segmentation and dynamic occlusion analysis simultaneously, the scheme attempts to improve successively over time the accuracy of the object boundary and motion estimation.

An efficient technique for expressing document image is required as part of a unified approach to document image processing. This paper presents a new method, Minimum Covering Run (MCR), for expressing binary images. The name being adapted from horizontal or vertical run representation. The proposed technique uses some horizontal and vertical runs together to represent binary images in which the total number of representative runs is minimized. Considering the characteristic of above run types precisely, it is shown that horizontal and vertical runs of any binary image could be thought of as partite sets of a bipartite graph. Consequently, the MCR expression that corresponds to the construction of one of the most interesting problems in graphs; i.e., maximum matching, is analogously found by using an algorithm which solves this problem in a corresponding graph. The most efficient algorithm takes at most O(n5/2) computations for solving the problem where n is the sum of cardinalities of both partite sets. However, some patterns in images like tables or line drowings, generally, have a large number of runs representing them which results in a long processing time. Therefore, we provide the Rectangular Segment Analysis (RSA) as a pre-processing to define runs representing such patterns beforehand. We also show that horizontal and vertical covering parts of the proposed expression are able to represent stroke components of characters in document images. As an implementation, an efficient algorithm including arrangement for run data structure of the MCR expression is presented. The experimental results show the possibility of stroke extraction of characters in document images. As an application, some patterns such as tables can be extracted from document images.

A model of a single neuron with chaotic dynamics is implemented with current-mode circuit design technique. The existence of chaotic dynamics in the circuit is demonstrated by simulation with SPICE3. The proposed circuit is suitable for implementing a chaotic neural network composed of such neuron models on a VLSI chip.

Fiber-optic local area networks (LANs) with Fiber Distributed Digital Interface (FDDI) protocol have come into use as backbones connecting other small LANs. This paper describes the current status of LANs, reviews a number of issues that stand in the way of further development and look at the future of LANs. Demands for wide-area networks (WANs) connecting LANs and multimedia LANs including voice and image capability has been extremely strong, spurring progress in geographical expansion and throughput increase, now over 100Mbit/s. The logical choice of transmission medium for next-generation systems is single-mode optical fiber, not only for backbone LANs but also, eventually, for floor LANs.

Single-mode fibers with intentionally induced periodical residual strains (IIPRS) along the fiber length are proposed for the suppression of the stimulated Brillouin scattering (SBS). A change of the residual strain along a fiber will change the Brillouin frequency shift, resulting in a broadening of the Brillouin gain profile. Such an increase of the line-width of the gain profile will cause a decrease of the gain coefficient which will raise the threshold power of the stimulated Brillouin scattering in optical fibers. Two types of the IIPRS fibers were fabricated. The residual strain of one IIPRS fiber is modified rectangularly while that of the other is changed triangularly. The measured spectra of the SBS are compared with that of a fiber with a constant strain. Using a novel mathematical model presented in this report, the possible improvements of the threshold powers for these two IIPRS fibers over the constant-strain fiber can be assessed through the SBS spectra. Finally, the achieved improvements are confirmed with the experimental results. The estimated improvement of the threshold for the IIPRS fiber with the rectangular profile is 2.9dB while the measured is 2.4dB. In case of the IIPRS fiber with a triangular profile, the improvement of the threshold is 5.4dB by estimation and is 5.1dB by experiment. While the limit of the threshold improvement for rectangular IIPRS fibers is 3dB, the threshold improvement for triangular IIPRS fibers is limited only by the allowable deviation of the tension applied during the drawing of fibers. It is estimated that a 5dB improvement is not difficult to realize.

Selective epitaxial growth technology has been extended to the base formation of a transistor on the basis of the SATURN (Self-Alignment Technology Utilizing Reserved Nitride) process, a high-speed bipolar LSI processing technology. The formation of a self-aligned base contact, coupled with SIC (Selective Ion-implanted Collector) fabricated by lowenergy ion implantation, has not only narrowed the transistor active regions but has drastically reduced the base width. A final base width of 800 and a maximum cut-off frequency of 31 GHz were achieved.

To construct a Fiber-To-The-Home network, high count optical fiber cables are needed. The requirements for these cables are small diameter, light weight, and high capacity. We studied the cable structures for ribbon fiber, which are useful for quick splicing. We calculated the diameter of three types of cables: a slotted rod cable, a loose tube cable and a newly developed U-groove cable. When the same ribbons are cabled with the same clearance, the cross sectional area of the U-groove cablet is about 27% less than that of the other two cables. No problems with the manufactured 1500-fiber U-groove unit cable are detected by the conventional cable testing.

Mathematical morphology clarified geometrical properties of shape analysis algorithms for binary pictures. Results of labelling, distance transform, and adjacent numbering are, however, coded pictures. For full descriptions of shape analysis algorithms in the framework of mathematical morphology, it is necessary to extend morphological operations to code-labelled pictorial data. Nevertheless, extensions of morphology to code-labelled pictures have never discussed though the theory of gray morphology is well studied by several authors. Hence, this paper proposes a theory of the coded morphology which is based on the binary scaling of labels of pixels. The method uses n-layered binary sub-pictures for the processing of a picture with 2n labels. By introducing morphological operations for the coded point sets, we express some coding functions in the manner of the mathematical morphology. We also derive multidimensional array registers and gates which store and process coded pictures and morphological operations to them by proposing basic gates which compute parallelly logical operations for elements of Boolean layered arrays. These gates and registers are suitable for the implementation of the shape analysis processors on the three-dimensional VLSI and ULSI.

A new redundancy technique especially suitable for ultra-high-speed static RAMs (SRAMs) has been developed. This technique is based on a decoding-method that uses two kinds of fuses without introducing any additional delay time. One fuse is initially ON and can be turned OFF afterwards, if necessary, by a cutting process using a focused ion beam (FIB). The other is initially OFF and can be turned ON afterwards by a connecting process using laser chemical vapor deposition (L-CVD). This technique is applied to a 64 kbit SRAM having a 1.5-ns access time. The experimental results obtained through an SRAM chip repaired using this redundancy technique show that this technique does not introduce any increase in the access time and does not reduce the operational margin of the SRAM.

Gradient-based methods for the computation of the velocity from image sequences assume that the velocity field varies smoothly over image. This creates difficulties at regions where the image intensity changes abruptly such as the occluding contours or region boundaries. In this letter, we propose a method to overcome these difficulties by incorporating the information of discontinuities in image intensity into a standard local optimization method. The presented method is applied to the synthetic and real images. The results show that the velocity field computed by the proposed method is less blurred at region boundaries than that of the standard method.

The 22 mechanical optical switch for single mode fiber (SMF) is reported. By using the precision grinding and molding techniques all-plastic multiple-fiber connector, 22 pin-referenced indirect slide switch is developed. The characteristics and the reliability test's results of this optical switch are also reported. Evaluations confirm that the switch has low insertion loss, high-speed switching, stable switching operations and reliability in practical applications.

We have proposed a new omnidirectional image sensor COPIS (COnic Projection Image Sensor) for guiding navigation of a mobile robot. Its feature is passive sensing of the omnidirectional image of the environment in real-time (at the frame rate of a TV camera) using a conic mirror. COPIS is a suitable sensor for visual navigation in real world environment with moving objects. This paper describes a method for estimating the location and the motion of the robot by detecting the azimuth of each object in the omnidirectional image. In this method, the azimuth is matched with the given environmental map. The robot can always estimate its own location and motion precisely because COPIS observes a 360 degree view around the robot even if all edges are not extracted correctly from the omnidirectional image. We also present a method to avoid collision against unknown obstacles and estimate their locations by detecting their azimuth changes while the robot is moving in the environment. Using the COPIS system, we performed several experiments in the real world.

Correspondence based on regions rather than lines seems to be effective, as regions are usually fewer than other image features and provide global information such as size, color, adjacency, etc. In this paper, we present a region matching approach for solving the correspondence problem. Images are segmented into regions and are individually described by classification tables using region adjacencies. From the structural description of the two images, the region matching process based on color and structural similarity is carried out. First, a small number of significant regions are selected and matched by using color, and then they are used as handles for constraint propagation to match the remaining regions by using structures. Our technique was implemented by using an efficient selection and propagation algorithm and was tested with a variety of scenes.

The authors recently proposed a design method of stable IIR digital filters based on the interpolation by rational characteristic functions of filters, for a set of values of these characteristic function and, in addition, their higher derivatives prescribed at a number of frequency. This method can be further extended so that, despite usage of a less number of interpolation points, almost the same filter characteristics as one obtained by the former method can be realized. This paper presents an improved design method for making the transfer function meet strict magnitude specifications. The method proposed in this paper is especially efficient for designing a filter whose characteristics is specified not only in the passband but also in the transition band with relatively narrow bandwidth.

We present a navigation system using ultrasonic sensors for unknown and dynamic indoor environments. To achieve the robustness and flexibility of the mobile robot, we develop a behavior-based system architecture, consisting of multi-layered behaviors. Basic behaviors required for the navigation of a mobile robot, such as, avoiding obstacles, moving towards free space, and following targets, are redundantly developed as agents and combined in a behavior-based system architecture. An extended potential filed method is developed to produce the appropriate velocity and steering commands for the behaviors of the robot. We demonstrate the capabilities of our system through real world experiments in unstructured dynamic office environments using an indoor mobile robot.

In this paper, we propose an algorithm of O(|V|min{k,|V|,|A|}|A|) time complexity for finding all k-edge-connected components of a given digraph D=(V,A) and a positive integer k. When D is symmetric, incorporating a preprocessing reduces this time complexity to O(|A|+|V|2+|V|min{k,|V|}min{k|V|,|A|}), which is at most O(|A|+k2|V|2).

Surface reconstruction and visualization from sparse and incomplete surface data is a fundamental problem and has received growing attention in both computer vision and graphics. This paper presents a computational scheme for realistic visualization of free-formed surfaces from 3D range images. The novelty of this scheme is that by integrating computer vision and computer graphics techniques, we dynamically construct a mesh representation of the arbitrary view of the surfaces, from a view-invariant shape description obtained from 3D range images. We outline the principle of this scheme and describle the frame work of a graphical reconstruction model, we call arbitrarily oriented meshes', which is developed based on differential geometry. The experimental results on real range data of human faces are shown.

This report will present an expression for the mechanical behavior of a drum-wound dual coated fiber and an analytical expression for the microbending loss in single mode dual coated fibers. These analytical expressions are then compared with experimental drumwinding microbending loss results to determine their validity.