Katsuo Ikeda

On-line recognition of hand-written characters utilizing positional and stroke vector sequences

Abstract An on-line recognition method for hand-written characters utilizing stroke vector sequences and a positional vector sequence has been developed. The number of target characters is about 2000, and fairly good recognition scores have been attained. Our scheme uses the number of strokes as the primary parameter. We employ three types of recognition strategy depending on the number of strokes. The general stroke vector sequence method, devised to analyze the shape, can represent both skeleton and local characteristics by a small amount of information; and the restricted dynamic programming method is effective to determine the shape of a stroke. The similarity of two shapes and the complexity of a stroke have been introduced to reduce the dictionary size and the processing time, respectively.

Collinear trinocular stereo using two-level dynamic programming

An almost occlusion-free trinocular stereo algorithm is described. It can cope with the occlusion problem when trying to obtain depth data of good accuracy by using a long stereo baseline. A third camera located midway between a pair of stereo cameras is used for the purpose. A correspondence search algorithmbased on two-level dynamic programming was developed to obtain an optimal correspondence among the three images. Experiments showed the validity of the algorithm.<<ETX>>

An analysis of Pascal programs in compiler writing

A method and results of static and dynamic analysis of Pascal programs are described. In order to investigate characteristics of large systems programs developed by the stepwise refinement programming approach and written in Pascal, several Pascal compilers written in Pascal were analysed from both static and dynamic points of view. As a main conclusion, procedures play an important role in the stepwise refinement approach and implementors of a compiler and designers of high level language machines for Pascal‐like languages should pay careful attention to this point. The set data structure is one of the characteristics of the Pascal language and statistics of set operations are also described.

Interpreting engineering drawings of polyhedrons

A system is discussed that restores solid models, or a set of polyhedra consistent with a given set of three orthographic views which are input by using a facsimile device. Emphasis is on the description of two novel techniques: the line-segment extraction method and the polyhedron restoration method. The line-segment extraction is performed by using a probe, a small fragment of line, which moves along the central axis of each line segment represented by a binary image. Therefore, the method does not require any preprocessing such as noise elimination, or thinning of the given binary image. The polyhedron restoration method uses a face-oriented approach, rather than the conventional wire-frame-oriented approach. The method is basically a combinatorial search procedure that finds all of the legal combinations of possible faces.<<ETX>>

Fault diagnosis and automatic reconfiguration for a ring subsystem

Abstract A ring subsystem has been developed for a full-scale high performance heterogeneous computer network. The design goals and the implementation issues of the automatic reconfiguration of the ring subsystem are presented. Particular emphasis is laid upon reliability improvement techniques, based on duplication of the ring subsystem components, and the automatic reconfiguration algorithm, which determines network configuration when faults occur.

GAMMA-NET: A local computer network coupled by a high speed optical fiber ring bus — system concept and structure

Abstract The concept and structure of a local computer network are presented for a full scale high performance computer network coupled by a dual 32 Mbps optical fiber ring bus. The design goals of the system are efficient resource sharing and improved RAS. Implementation issues of the system are discussed, focussing on the optical fiber ring bus and the network operating system services. The experimental results also include the processing times for a data link connection/disconnection, the synchronous delay time for a read/write operation matching, and the data transmission speed and efficiency of both the multiplex mode and the burst mode.

Network management in a local computer network

The functions and structure of the network management subsystem of the GAMMA‐NET, a local computer network at the University of Tsukuba, are presented. The network management subsystem is an integrated subsystem that offers a convenient man‐machine interface for the network users during the execution of required jobs, and levels the workload throughout the system, as well as managing the network operations.

Reducing the retrieval time of hashing method by using predictors

Many methods for resolving collisions in hashing techniques have been proposed. They are classified into two main categories: open addressing and chaining. In this paper, other methods are presented that are intermediate between the two categories. The basic idea of our methods is the use of one or more predictors reserved per cell instead of a link field as in the chaining method. The predictors are used to maintain loose synonym chains. After describing the methods, the efficiencies are estimated theoretically and verified experimentally. In comparison with the chaining method, we prove that our methods significantly reduce the average number of probes necessary to retrieve a key without expending extra space.

False-contour removal by random blurring

Abstract A method is presented for eliminating spurious brightness discontinuities, or false contours, in areas in which brightness varies gradually, while preserving edge sharpness. The basic idea of the method is to randomly blur points only in the neighborhood of each border on which those spurious brightness discontinuities may occur. The method is used for producing natural appearance of a picture for the human eye, not for picture analysis.

GAMMA - NET: Computer network coupled by 100 MBPS Optical Fiber Ring Bus - system planning and Ring Bus subsystem description

Planning and design considerations are presented for a full scale high performance heterogeneous computer network coupled by a 100 MBPS optical fiber ring bus. The design goals of this system are efficient resource sharing and improved RAS. All common resources, such as processors, peripheral devices, terminals and file devices, are directly connected to the ring bus, instead of directly to a processor. This network includes two or more large computers of different types, a guide subsystem to manage common resources and to control their usage, peripheral and terminal control subsystems, and a gateway processor.