bluuebunny/crossref_metadata_2025 huggingface dataset:
Transition from quality circles to total involvement in semiconductor manufacturing
Authors: Derry Carol A.
Published: July 2007

Eight years of experience with quality circles has shown a progression toward the achievement of total quality. Significant positive results have led to the evolution from a voluntary programme to the implementation of a non‐voluntary programme that includes functional supervisors. Each team meets for an hour per week during normal work hours as an integral part of the job. Over 83 per cent of manufacturing and support groups employee participation has been recorded to date and at present 62 teams are functioning. This article will present the details of this programme's progress towards quality excellence.
Good quality at low cost: Trends in quality assurance
Authors: Fleischhammer Werner
Published: July 2007

For as long as electronic devices have been produced the relationship between the costs and benefits of quality assurance has been discussed. At present this relationship is influenced by the increase in the complexity of integrated circuits and by the growing extent of automation in production. In this paper a way is presented showing how the cost of quality assurance can be decreased without loss of quality. Six steps to achieving this goal are described.
Ultrasonic microscope investigations of die attach quality and correlations with thermal resistance
Authors: Pfannschmidt Gabriele
Published: July 2007

In the semiconductor industry the use of ultrasonic microscopes for evaluating the integrity of the bond between adjacent surfaces has increased dramatically over the last few years. These instruments are rapidly becoming an acceptable diagnostic tool in the QC laboratory and new specifications have been written incorporating them into MIL requirements. Especially in the non‐destructive investigation of plastic encapsulated ICs for delaminations, cracks, voids, and die‐bonding faults ultrasonic microscopy has great advantages. The main equipment used is SLAM (or through transmission mode acoustic microscope) with a frequency range of 10–200 MHz and C‐SAM (or reflective mode acoustic microscope) working in the range 5–100 MHz. In this paper, standard measurements of die attach quality and thermal resistance are correlated with C‐SAM results. A general correlation between the amount of delamination and the measured thermal resistance was found.
Electromigration at gold–aluminium interfaces and in thin aluminium tracks
Authors: Vanhecke B. , de Schepper L. , de Ceuninck W. , D'haeger V. , D.'olieslaeger M. , Beyne E. , Stals L. , Roggen J.
Published: July 2007

The in situ method to study accelerated ageing of electronic interconnections under current stress has been applied to (a) Au ball bonds on A11% Si metallization, and (b) thin aluminium tracks. For the Au ball bonds, it has been shown that direct current stresses above 108 Am−2 cause electromigration effects at the Au‐Al interface, and that the ageing behaviour depends on the direction of the applied direct current stress. It was also shown that the addition of 1 per cent Cu to the metallization strongly retards void formation, and hence open contact failure. For the thin aluminium tracks, it has been shown that the early stage of electromigration, which can be studied accurately with the in situ technique, is closely related to the stress relaxation within the track. It is therefore concluded that the kinetics of electromigration can only be described if the kinetics of stress relaxation are well understood.
Improved structural reliability assessment using non‐linear regression techniques to process raw fatigue crack growth test data
Authors: Stavrakakis G. S.
Published: July 2007

A new method is proposed to process raw fatigue crack growth (FCG) test data for estimating the parameters of any crack propagation (FCG) model. This method is based on iterative minimization techniques for non‐linear regression, extensively available in the literature. The method presented here permits a significantly reduced contribution of the variability inherent in the usual raw FCG data processing techniques to the predictions of the crack length distributions derived by any analytical FCG model and, consequently, improved structural reliability assessment is achieved.
Thermoreflectance optical test probe for the measurement of current‐induced temperature changes in microelectronic components
Authors: Claeys W. , Dilhaire S. , Quintard V. , Dom J. P. , Danto Y.
Published: July 2007

We have developed an optical laser probe for the measurement of absolute surface temperature changes in integrated circuits. The experimental method is based upon thermoreflectance, which is the change in reflectance due to surface temperature changes of the device. A laser beam is focused upon a small spot of an operating circuit. The reflected intensity is recorded upon a photodiode in synchronism with the circuit periodic excitation signal. We calibrated the device by developing a simple analytical model to calculate the surface temperature behaviour of a silicon resistive structure we tested. The value we derived for the relative reflectance temperature coefficient of silicon is in excellent agreement with the value from the literature. The results show the laser probe to be a fast surface thermometer (DC to 10 MHz), with excellent lateral resolution (1 μm), with high sensitivity (10−3°C) and large dynamics (ΔT: 102 to 10−3°C).
Quality and 1/f noise of electronic components
Authors: Konczakowska Alicja
Published: July 2007

Classification rules of electronic components based on their 1/f noise measurements are presented. It is proposed to classify electronic components into four groups with different quality: high, good, low, poor. The results of investigations of type BF 414 transistors are reported.
Estimating process capability indices for non‐normal pearsonian populations
Authors: Pearn W. L. , Chen K. S.
Published: July 2007

Clements1 introduced a method for calculating the estimators of two classical process capability indices (PCI), Cp and Cpk, for non‐normal Pearsonian populations. Pearn and Kotz2 applied Clements' method to obtain first approximation estimators of PCIs for non‐normal populations to the two more advanced PCIs, Cpm and Cpmk developed by Chan et al.3 and Pearn et al.4 In this paper, we consider a different approach for calculating the estimators of the four PCIs. The new approach may be viewed as a modification of Clements' method. Comparisons between Clements' and the proposed new methods are also provided.
A multichannel CSMA/CD method in bus‐type local area networks
Authors: Nomura Yoshifumi , Nakanlshl Yoshiro , Okada Hiromi
Published: July 2007

The CSMA/CD method, one of the communication schemes for bus‐type LANs, has problems with respect to transmission capability and its function. This paper presents an access control method named multichannel CSMA/CD for local area networks. In this method, CSMA/CD combined with a new load distribution mechanism and channel selection function is extended to multichannel organization. This method aims at LANs having high performance and multiple functions. As a result of performance evaluation, multichannel CSMA/CD is shown to be superior to the original CSMA/CD with respect to (1) total transmission capacity, (2) throughput‐delay characteristic performance, (3) channel stability and (4) adaptability to various kinds of user demands in networks.
Fusion algorithm not affected by the picture frame
Authors: Suzuki Satoshi , Abe Keiichi
Published: July 2007

This paper discusses the properties and the algorithms of the fusion operations, which are one of the fundamental techniques of binary image processing. First, a theoretical discussion is made for infinitely spread images, deriving several properties for the fusion operations. Those properties indicate the equivalence among the fusion operations and their iterations and combinations. Since the actual input images are finite, those properties are not satisfied by a simple algorithm due to the effect of the picture frame. This paper presents algorithms not affected by the picture frame for the general‐purpose sequential computers and for the dedicated parallel‐processing hardwares. Those algorithms perform the fusion operation by executing the first operation in the fusion (that is, the expansion or the contraction) together with the distance transformation, and by performing the second operation using the distance information obtained in the first. The proposed algorithms have the feature that most of the properties for infinite images also apply to images of finite size. With this feature, the proposed algorithms are shown to be suited to parallel processing with a small number of processors.
Measurement of three‐dimensional position and orientation of a plane‐like object
Authors: Nonmember Heng‐Li Guo , Yachida Masahiko , Tsuji Saburo
Published: July 2007

This paper describes a method to determine the 3‐D position and orientation of a plane‐like object. The system first extracts edges of the plane‐like object and its shadow cast on a working table by an ideal point light source. Utilizing the shadow informaton effectively, it estimates the 3‐D positions of several boundary points, from which the position and orientation of the plane‐like object are then determined. An application of this method, measurement of the 3‐D position, and orientation of a printed circuit board, is presented. The errors in measuring the position and orientation are about 1% of the size of sight and 4 degrees, respectively. The result is sufficient for a robot hand to manipulate the printed circuit board.
Management of time‐series data by feature description based upon generative grammar, fitting ARMA model to EEG signals
Authors: Tokinaga Shozo
Published: July 2007

In the retrieval of stored time‐series data, as means for improving the retrieval efficiency and for the pre‐processing of classification, it is effective to utilize the time‐domain characteristics of the time‐series data as the key in the retrieval. This paper presents a method which describes the feature of elec‐troencephalographic time‐series in a simple linguistic form and to perform data management based on that description. First, the ARMA model is applied to the general non‐stationary time‐series which is partitioned into small intervals based on the spectrum estimation error. At the same time, for the cases where a sporadic (transient) waveform is included, the transient wave is detected effectively by adaptively modifying the input to the model. Then identifying the class of the transient wave using recognition procedures such as smoothing, the features of EEG are determined for the background and the transient waves. A linguistic expression is derived by applying predetermined production rules to those features. The properties of the linguistic expression are discussed, together with the reproducibility of the original data time‐series and the compression of the original data. This indicates that the proposed method is a simple and effective means of representing EEG. Finally, a method is described for retrieval of time‐series data based on linguistic expression, which can cope with the ambiguity of expressions.
An edge detection algorithm of color images using the reduction of brightness and chroma
Authors: Agui Takeshi , Nakajima Masayuki , Sugita Atsushi
Published: July 2007

In the present layout scanner, the operations for changing color partially, or extracting a portion of it, have been done interactively by specifying the location through a digitizer. Usually, image analysis techniques and artificial intelligence techniques are applied to region extraction and region matching operations. This paper describes an edge detection algorithm which is the most basic operation of color image processing.

First, attention is given to effective gray scale intensity analysis of the gray level image. Then the concept of the reduction of brightness and chroma is considered as an addition of the differences in terms of hue and chroma to the differences in terms of brightness. Based on that concept, the difference equation is derived and the edge detection experiments are reported.
Proposal on infrared ray emission CT
Authors: Uchiyama Hiroki , Takezawa Takayuki , Abe Keisuke , Haku Shouken , Nakajima Masato , Yuta Shinichi
Published: July 2007

This paper presents a proposal for infrared ray emission computed tomography (IRECT). This is a method for visualizing the two‐dimensional physical quantum distributions (e.g., temperature, concentration) on an arbitrary transaxial layer of an object by calculating the infrared radiation intensity emitted from the object as the projection data. To verify the usefulness of this method, an experimental system with pyroelectric detector is developed for measuring flame temperature distribution and this system is applied to a Bunsen flame. The experiments yield good images of thermic intensity distribution in the cross section of the flame. In addition, the usefulness of this method in measuring temperature distribution is confirmed by comparing the results with thermocouple probe measurement.
Vulnerability of a communication network with a satellite
Authors: Hagihara Ken'Ichi , Masuzawa Toshimltsu , Tokura Nobuki , Ikeda Mitsuji
Published: July 2007

The vulnerability of an integrated communication network composed of a terrestrial network and a satellite network is discussed in a graph‐theoretic manner. A ground switching station (a switch board) is abstracted as a vertex, a wire and an antenna, respectively, for a communication with a satellite as an edge of a graph. As a measure of the vulnerability of a communication network we introduce anew the concept of “S‐connectivity.” Although the concept of S‐connectivity is obtained by generalizing the conventional idea of vertex‐connectivity, since it takes into consideration the difference in the reliability between a satellite as a wireless transistor and a ground station controlled by software, it appears suitable as a means to determine the vulnerability of a communication network consisting of a terrestrial network and a satellite network.

This paper discusses: (1) What is the S‐connectivity when antennas that transmit to and receive from a satellite, are used on each ground station? (2) If ground stations exist which cannot communicate through the terrestrial network, at which stations should antennas be installed to enable communications with the minimum number of antennas via satellite? (3) When the number of edges of a terrestrial network is fixed, what kind of terrestrial network maximizes the S‐connectivity? (4) What are the computation times of algorithms for solving the preceding problems (1) and (2)?
A VLSI‐oriented interconnection network having self‐similarity
Authors: Tatsumi Shoji , Sakai Toshikazu
Published: July 2007

This paper proposes a construction method for the large‐scale multiprocessor system, which is composed of a large number of processors and memories. There can be two configurations for the large‐scale multiprocessor systems. One is the configuration composed of the switching network among processors and memories, as is seen in the case of the omega network. The other is the processor network which is the graph composed of processors, with the processor being regarded as a node. The interconnection network proposed in this paper belongs to the latter category. It is a VLSI‐oriented interconnection network, where the multiprocessor system is implemented on a silicon wafer. The method of construction is developed from the viewpoint of factual geometry, where self‐similarity is considered among figures. The basic unit of the interconnection network is the structure composed of the processor, memory and bus. The system is constructed by recursively using the basic units. To compare the proposed system with other typical VLSI‐oriented interconnection networks, such as the tree and the snowflake interconnection networks, the maximum distance between processors, the mean distance between processors and the maximum message density, which is considered as the maximum communication load for the routing and node processors, are calculated.

The result verifies the effectiveness of the proposed interconnection network.
Interrupt handling in the loosely synchronized TMR system
Authors: Yoneda Tomohiro , Suzuoka Takashi , Tohma Yoshihiro
Published: July 2007

This paper discusses problems in the implementation of interrupt handling in the loosely synchronized Triple Modular Redundancy (TMR) system where synchronization, majority‐decision and fault diagnosis are performed by software. The method of solution for the problems also is discussed. The major problems are as follows: (1) For the interrupt coming into three processors with a certain time difference in the task progress, the consistency among the global areas of the processors must be maintained; (2) The synchronization must be maintained among processors, which do not recognize interrupts due to the interrupt‐inhibit period containing synchronization, and the processors, which recognized the interrupts; (3) When interrupts at different levels arrive at a processor, each processor must identify the interrupt with the highest priority consistently. To solve these problems, we have developed a multitask scheduler, which provides the variable representing the number of access to the global area, the flag indicating the interrupt‐inhibit area, and the variable keeping the record of the accepted levels. This scheduler also controls the interrupt process by mutually referring those variables and flags. The system is implemented in SAFE system, and the overhead in the interrupt handling was measured.
A redundancy reduction of black and white documents by an encoding system with line skip scanning
Authors: Okamoto Noriyoshi , Klkuchi Toshiyuki , Nakamura Osamu , Minami Toshi
Published: July 2007

A new method is considered which integrates the READ scheme and the line skip scanning scheme, and nonreversible coding, which provides as good image quality as reversible coding. A binary document image was used. Its basic idea consists of decomposing the object image into small regions and examining the reconstructability of the image for each small region.

It is expected that a high compression ratio will be achieved by changing the scanning density based on the results. Now, the change of scanning density is accomplished by line skip scanning and skipped line ranges from 1‐3. Also, the reconstructability of the image is determined by the strength of correlation which is examined by the relative distance distribution among the scan lines corresponding to the number of each skip line. As a result of experiments on ten kinds of test charts including the CCITT test chart, the compression ratio is 1:5.05 to 1:54.3. Therefore, in comparison with the READ scheme, about 59.7 percent of the compression ratio is improved. Also, it has been shown that 99 percent of all transmitted pixels is reconstructed exactly in terms of reconstruction accuracy.
A method for recognition of words spoken in noisy environment
Authors: Kamei Hiroyuki , Kawarada Hiroshi
Published: July 2007

A method for recognizing words spoken in a noisy environment is proposed . A 23‐channel filter bank is used to analyze noisy speec h. The output of each channel is transformed into a pulse trai n. From the autocorrelation functions of these pulse trains, the pitch period of speech is detected and the spectrum is estimated at each fram e. Word recognition is carried out by DP‐matching algorithm using the distance measure weighted by the correlation coefficien t. The results of experiments where white noise, traffic noise, and an engine sound were used as additional noises show the effectiveness of this system.
Morphological analysis of neurons by computer
Authors: Yokoyama Kiyoko , Ishii Naohiro , Suzumura Nobuo
Published: July 2007

One of the most important problems in biology is the morphological classification of cells as well as analysis of the relation between the morphology and function of the cell. Such analysis requires the extraction of feature parameters from cell images and classification based on their correlations. This paper seeks to design an image database whereby a number of cell images is stored in a computer for calculation of feature parameters and for the retrieval and automatic classification of images. A new algorithm for image processing is developed for acquisition of cell images. A procedure is developed to store cell images for calculation of feature parameters and automatic classification. In the past, attempts have been made to describe single cell images in accurate detail (e.g., by three‐dimensional reconstruction of the cell image). However, those methods are not suited to the design of an image database in which a large number of cell images must be handled. From such a viewpoint, a method for morphological classification and feature analysis is developed whereby a cell image is represented by fewer feature parameters, making it possible to handle a large number of cell images. The method for acquisition of cell images, their storage and processing for feature extraction is systematically developed, arriving at a classification method based on those feature parameters. Factor analysis is applied to analyze the correlations among the feature parameters.
Extraction of roads from topological maps using a parallel extraction algorithm
Authors: Miyatake Takafumi
Published: July 2007

One of the most important techniques in drawing recognition and understanding is to extract the effective components from a complex image according to the purpose of analysis. This paper considers the map which is the most complex among images, and describes an automatic method to extract roads. In general, roads are represented in the map by parallel lines. Consequently, the extraction of roads from a map is formulated as a problem of extracting parallel lines. A method is proposed which directly extracts parallel lines from the image and describes the parallel lines by the spacing and the path of the central line. Two technical problems are contained in this approach. One is the parallel‐line extraction, which extracts parallel‐line areas (inside the parallel lines) from the image, and the other is the line vectorization, which determines the coordinates for the path line of the extracted area. For the latter, numerous proposals have been made such as line‐image thinning and line tracing, and the problem is almost solved. From such a viewpoint, this paper discusses primarily the former, i.e., the parallel‐line extraction. One of the difficult problems in the extraction of parallel lines from the image is the processing of the area where parallel lines intersect. A generalized expansion‐contraction of the image is proposed to solve this problem. The proposed method is applied to a map issued by the National Geographical Institute, and is verified as effective as a method of road extraction.
Matrix representation of programs within an intelligent link
Authors: Miyajima Jun , Endo Noboru , Nakamura Tadao , Shigei Yoshiharu
Published: July 2007

This paper presents an outline of a prototype intelligent link system proposed to combine “data transmission” and “data processing” and its software system. The generative program and its processing scheme are reported in detail. The intelligent link is n pairs of a general‐purpose pipeline processing system. It is an n‐stage one‐dimensional line of segments which consists of a transmission line and a processor. Each segment processes received data by the programs which tag along with its data. In order to decrease the system processing time and the processor idle time, fewer bits are employed to represent a program for the information transmission. Here we use a transition matrix method to describe transition of the operations in a program. First, we introduce the matrix properties and discuss applications of the matrix representation for generative programs. Secondly, we study how fewer bits can be used to represent a matrix and, as a result, find that less than 70% of the bits required to represent a matrix directly suffices in the proposed method.
Structural analysis of line patterns using distance transformation (DTLP)
Authors: Suzuki Hidetomo , Toriwaki Jun‐Ichiro , Shin‐Yashiki Hitoshi
Published: July 2007

This paper discusses the structural analysis algorithm for line patterns, based on the distance transformation of a line pattern by iterative local parallel processing. Although parallel processors have been applied recently to image processing, the processing of line patterns in the past was based primarily on the transformation of the object pattern into the list structure or symbol strings. Few studies have been made on the parallel processing algorithm for a line pattern. From such a viewpoint, this paper presents parallel‐type algorithms for loop counting, loop extraction and arc decomposition, among the procedures for processing line patterns. Properties of these algorithms also are discussed. The method proposed here is based on the distance transformation (Min. type) for line patterns we developed, and can be performed by iterative local parallel processing, in the same way as the distance transformation itself.
Basics of algorithms for processing three‐dimensional digitized pictures
Authors: Toriwaki Jun‐ichiro , Yokoi Shigeki
Published: July 2007

This paper presents basic concepts and fundamental algorithms for processing three‐dimensional digitized images (3D images). A 3D image is a pictorial datum obtained by measuring physical quantities distributed at every point in 3D space and arranging the measurements on a 3D array. First, we present several basic concepts concerning geometrical properties of 3D images, which include connectivity, the connected component, the Euler number, and deletability. Then we explain outlines of basic algorithms derived by using the forementioned concepts based on research results by the authors' group. Procedures referred to here are as follows: calculation of the Euler number, deletability test of 1‐voxels, shrinking, thinning, and border following. Finally, we add 51 references which may aid more detailed research; these references also will supplement the brief explanations and small number of procedures we are limited to in this article.
Pattern Data representation and management in image database systems
Authors: Sakauchi Masao , Ohsawa Yutaka
Published: July 2007

Data representation and management in the image database system are discussed. It is pointed out first that both efficiency of representation (amount of data) and the efficiency of processing and retrieval are important in the representation and management of data. From this viewpoint, various kinds of image and graphics representations are discussed, arriving at the viewpoint of “management of M‐dimensional data in N‐dimensional space.” The point data (0 in N data) and the N‐dimensional image data (N in N data) are considered. Various kinds of data structures such as KD tree, KDB tree, 2N partition tree and linear tree, are discussed and analyzed from the viewpoint of the preceding two characteristics. Especially, a tree‐type data structure (called BD tree) is proposed where the N‐dimensional rectangular region is used as the partition key. The structure and the performance are discussed indicating that the performance is better than in other structures. Examples of applications of the proposed data structure in the image database are discussed, as well as the possibilities of future applications.
Interval matching method of stereo‐image using dynamic programming
Authors: Ohta Yuichi , Masai Yasuyuki , Ikeda Katsuo
Published: July 2007

In the search for correspondence in the stereo vision, a general method is to use dynamic programming and search the correspondence for a pair of left and right scanning lines. In this case, the edge is often used as the unit for the matching, but the method has a problem in the processing of occlusion and noise. To solve this problem, this paper proposes a method in which the interval between two edges is considered as the unit of matching. Three components are proposed as the cost evaluation in the interval matching, which are compared by using synthesized images. As a result, it is seen that the evaluation based on the variance of pixel intensities in the intervals is stronger against noise than the method based on the intensity difference of the intervals, which has been considered as the general method for the evaluation of similarity. The interval matching, using the cost function based on the variance, is applied to the stereo aerial photograph of an urban area, verifying its usefulness.
Data Abstraction Technique for Relational Database Query Processing
Authors: Ohtani Takumi , Baba Takanobu , Inagawa Masayuki , Iwasaki Takao , Okuda Kenzo , Yamazaki Katsuhirc
Published: July 2007

This paper proposes a schema conversion approach for relational database query processing. The approach not only maintains high data independence by encapsulating the data and its physical structures for a query with the procedures that manipulate them, but also aims to achieve high‐speed processing by dedicating the procedures to individual functions. This approach is experimentally compared with the interpretive and compilation methods in terms of data independence, performance and the procedure program size. The following conclusions are drawn from the experiments.

(1) Although the effect of the change in physical structure is greater than that of the interpretive approach in regard to data independence, only a limited number of parts are affected and they are easily reorganized by each dedicated procedure. (2) The performance is extremely close to that of the compilation approach regardless of the kind of computer and programming language. Furthermore, the overhead for calling the procedures can be further reduced with the use of microprograms and hardware. (3) Although the number of specialized procedures increases, this is compensated by the relatively small program size of each procedure.
Robot vision based on three‐dimensional model
Authors: Shirai Yoshiaki
Published: July 2007

It is desirable for flexible robot vision to have three‐dimensional models have no constraints are imposed on the scene. This paper proposes the use of geometric models generated during the CAD process to save model building efforts. Also, a hierarchical matching method to avoid search efforts for all possible attitudes of each model is proposed. Examples are described for three cases: 1) only a few surface normals are available; 2) all visible surface normals are available; and 3) range data are available. In all cases, efficient and flexible object recognition is realized by hierarchical matching based on three‐dimensional models.
representation of road environment understanding for a mobile robot by picture interpretation language PILS
Authors: Mori Hideo , Fudaba Izumi , Yokoyama Hiroaki
Published: July 2007

The picture interpretation language PILS·V‐1, which was already publicized, can handle essentially only the silhouette image, since the object and the background are separated in the pre‐processing. The system cannot handle a complex gray‐level image such as an outdoor scene. From such a viewpoint, PILS was improved as follows. The gray‐level image is partitioned into subregions based on the differential image in the pre‐processing. Each region is represented by global parameters such as the coordinate of the center, area, height, width and color. In the recognition stage, the object is recognized from the background, using the a priori knowledge of the object concerning the global parameters. This paper first discusses the representation of the gray‐level color image. Then using the outdoor road environment recognition by moving robot as an example, the programming in PILS for the object recognition algorithm based on the a priori knowledge is described. The result of computer processing is also shown.
SCOPE: Solid and colored object projection environment
Authors: Uchiki Tetsuya , Tokoro Mario
Published: July 2007

SCOPE (Solid and Colored Object Projection Environment) is an architecture which displays and manipulates free‐form objects. In SCOPE, an object of any form is stored in PEARY, a three‐dimensional picture element (voxel) array. Thus a solid object can be represented with colors and volume, independently of the object modeling.

In this paper, we describe the SCOPE architecture, the algorithm, and its evaluation by a simulator. This algorithm produces solid images using visible object searches from some viewpoint. An implementation of a fast SCOPE architecture using a parallel processor is also shown.
Availability of redundancy of projection data applied to reduce the noise sensitivity of reconstructed images
Authors: Kumazawa Itsuo , Iijima Taizo
Published: July 2007

Previously, in the processing of CT projection data, it was assumed that the measured values are independent at each point. Here it is shown that the actual data have a dependent property, which is called the redundancy of the projection data. It is shown that the redundancy is effective for the reduction of the noise sensitivity of the reconstruction formula. This paper evaluates the effect qualitatively and experimentally in comparison with the convolution method, which is the mainstream of the present reconstruction procedure. The reconstruction formula (formula II), which was derived in a previous paper to reduce the noise sensitivity utilizing the redundancy, is compared with the convolution method. The analytical comparison with the mean‐square error as the evaluation measure, as well as the visual comparison of the actually reconstructed examples, are performed.
Signal processing on a parallel pipeline‐structured data‐flow computer system
Authors: Oba Nobuyuki , Nakamura Tadao , Shigei Yoshiharu
Published: July 2007

There are still many problems left before the data‐flow computer can be realized, for example, execution control based on the data‐flow principle, system architecture and load distribution. This paper proposes a method for improving the speed of execution control, which distributes the matching process by using more than one execution control unit. The proposed units are connected in cascade with more than one operational unit. The structure is called PP. By operating the PP structure in a pipelined scheme, the execution control and operational processing with higher‐speed can be realized. It is also shown that a more efficient load distribution can be achieved by the parallel pipeline structure, composed of the omeganetwork connecting more than one PP. Then the digital signal processing is considered as an example of the processing in the data flow computer. By applying the stream notion to the time‐series data, the concurrent parallel pipeline property is utilized, realizing a high‐speed processing.
Adaptive control of linear discrete‐time stochastic systems with colored noise and randomly switched parameters
Authors: Ohuchi Takao , Ohtomo Teruhiko
Published: July 2007

This paper describes a structure of the linear discrete‐time stochastic system which contains colored observation noise and changes its system parameters randomly due to, say, abrupt load changes. In the system under consideration, the switching system parameters are not identified during adaptive control; rather a priori identified parameters are used in determining the adaptive control input. First, an algorithm for optimal control from an arbitrary initial state to an arbitrary state space (target state) is derived by extending the dynamic programming technique. Also, an algorithm is derived for realizing the state estimate of a system with colored observation noise with a discrete‐time Kalman filter. Next, the a posteriori probability of each system parameter is found from the probabilities of system parameters at a certain time by using the Bayes' formula, and it is shown that the adaptive control input can be determined by summing the products of a posteriori probability and the optimal control input calculated from dynamic programming for each parameter. Also, the effectiveness of the proposed stochastic adaptive control algorithm is confirmed by computer simulation of a two‐dimensional model system and by comparing four different methods of probability calculation when the system parameters are switched randomly.
A new method of software structural testing by path analysis
Authors: Masuyama Hiroshi , Ichimori Tetsuo
Published: July 2007

This paper discusses the structural software testing method by path analysis. The problem of the method is discussed, and a coverage measure is proposed. The problem in the structural testing is discussed first. If the evaluation is made based on the past coverage measures, the quality of the software tends to be overestimated. A problem occurs of testing the cost when the number of steps for determining the test data increases with the size of the software. Also, another problem occurs wherein if a new coverage measure is introduced so that the quality is not overestimated, additional test cost is produced. From such a viewpoint, this paper proposes a method which can essentially avoid these problems by using the minimum number of test paths. An algorithm for determining the test paths is presented which is independent of the earlier method. Then it is shown that the number of test paths determined by that algorithm is the minimum. The total distance of the test paths is also discussed. Finally, the computational complexity in determining the test paths is discussed.
Studies on Noisy word recognition
Authors: Takahashi Kazuaki , Matsumoto Yoshihiro , Kobatake Hidefumi
Published: July 2007

This paper presents theoretical and experimental studies of the effect of noise on the speech spectrum. It is shown that the logarithmic spectrum is not suitable for the features of noisy speech because it is sensitive to stochastic noise effects when the signal‐to‐noise ratio is low. A new distance measure for spoken word recognition is proposed which is effective in evaluating the distance between the reference and the input under the influence of noise. Experiments in noisy word recognition show the effectiveness of the proposed method.
A region extraction method using a distance function between images
Authors: Nagao Tomoharu , Agui Takeshi , Nakajima Masayuki
Published: July 2007

This paper discusses the distance function between images and its application, which is applicable to any monochrome binary image and monochrome gray‐valued image with 2n × 2n pixels (n is a nonnegative integer). By denoting the original image as the 0th image, the first to the nth images are generated by successively partitioning the edges. Each image is composed of a finite number of subimages. Then the center of gravity is defined with the gray‐value of the pixel as the weight. Using these notions, the distance between images is defined between two images. The rotational transformation is introduced for the subimages of the images at each stage, and the application of the distance function between images is discussed. An application example is the region extraction in the geographical information processing. The extraction of the contour (equal‐height) line and the extraction of building region in the 1/25,000 map are discussed. The distance function between images proposed in this paper does not depend on the property of the original image, and is considered as being suited to the hierarchical processings.
A top‐down error‐correcting parser for a context‐sensitive language
Authors: Kobayashi Hironari , Ikeda Mitsuru , Tanaka Eiichi
Published: July 2007

A context‐free grammar, a stochastic grammar, and a context‐free tree grammar have been used in the past in the syntactic approach to pattern recognition. However, since a pattern is primarily context‐dependent, some top‐down and bottom‐up parsers have been proposed for context‐sensitive language (CSL). Although the bottom‐up version of the error‐correcting parser for CSL has been known, it has a disadvantage in that it converts an input string of length n into a string of length (n + 1) k + n (k is the maximum number of consecutive deletions of terminal symbols). As a result, this paper proposes a top‐down ECP (error‐correcting parser) for a context‐sensitive language.
Determining a depth map from a pair of needle maps by a pair of photometric stereo systems with region matching
Authors: Ikeuchi Katsushi
Published: July 2007

This paper describes a method for determining a depth map from a pair of surface‐orientation maps obtained by a pair of photometric stereo systems. A photometric stereo system determines surface orientations by taking three images from the same position under different lighting conditions, based on the shading information. A pair of photometric stereo systems can generate a pair of surface orientation maps.

Then the surface‐orientation maps can be segmented into isolated regions with respect to surface orientations, using a geodesic dome. The resulting left and right regions are compared to pair corresponding regions. The following three kinds of constraints will be used to search for corresponding regions efficiently: (1) a surface orientation constraint; (2) an area constraint; and (3) an epipolar constraint. Region matching is done iteratively starting from a coarse segmented result and proceeding to a fine segmented result, using a parents‐children constraint.

The horizontal difference in the position of the center of mass of a region pair determine the absolute depth value for the physical surface patch imaged onto that pair. This system takes only a few minutes to determine an absolute depth map in complicated scenes, on a Lisp machine, and could be used as an input device for a bin‐picking system.
Measurement of 3‐d objects using recorded image projection and two cameras
Authors: Aoki Norio , Yachida Masahiko , Tsuji Saburo
Published: July 2007

The measurement of three‐dimensional objects has been conducted by various methods such as by projection of a slit light pattern. One problem in previous methods is the time‐consuming procedure of inputting the image. In order to solve the time problem in image input this paper proposes a method which provides stereotaxic vision with two cameras by projecting a relatively complex pattern light on the object, revealing the three‐dimensional information of the object. The measurement method proposed in this paper has the advantage that correspondence between images can be made by repeating the same procedure, based on a virtual projection line called the epipolar line, without using heuristic information. Utilizing the projected pattern and two input images, unique correspondence can be established for a fairly complex projection pattern. Experiments are performed by projecting a slit pattern or a grid pattern and it is found that false correspondence is rarely generated by the grid pattern and a large number of points can be matched.
A discrete software reliability growth model with two types of errors
Authors: Kitaoka Takeshi , Yamada Shigeru , Osaki Shunji
Published: July 2007

As the social missions of computer systems increase, it becomes more important to develop high‐reliability software. For this reason software systems are tested repeatedly to remove latent errors in the testing phase during software development. One of the most interesting methods is to evaluate software reliability by using test data observed in the error‐detection process. In this paper we model the error‐detection process as a stochastic model and introduce several effective measures to evaluate software reliability. In modeling we use the number of test run trials as a unit of the error‐detection period and assume that the cumulative number of software errors detected in an arbitrary testing time interval is a nonhomogeneous Poisson process. Further, we consider the difficulty of error detection because the reliability of software is evaluated from the characteristics and frequency of the errors. Applying the model to the actual test data, we perform the goodness‐of‐fit test and infer the software reliability measures. Finally, we discuss an optimum software release problem based on the software reliability index.
Design of lsi‐oriented digital signal processing system Based on Pulse‐Train Residue Arithmetic Circuits
Authors: Tomabechi Nobuhiro , Kameyama Michitaka , Higuchi Tatsuo
Published: July 2007

This paper describes a design method of high‐speed digital signal processing systems suitable for LSI fabrication. It utilizes the pulse‐train residue arithmetic circuit as a basic building block. This circuit lends itself to parallel and pipeline operations suitable f o r high‐speed digital signal processing, and permits modular‐design of the systems. A new master‐slice LSI on which the pulse‐train residue arithmetic circuits are arranged regularly, is presented. A method of minimizing the chip‐area for NMOS fabrication of the master‐slice is discussed. The layout of the pulse train residue arithmetic circuits on the LSI chip, and several parameters of the master‐slice such as the number of channels are discussed. Some demonstrative examples are presented to show the application of the master‐slice in the design of digital filter. The design method using master‐slices is relatively simple; it minimizes the chip‐count and improves the processing speed.
Determinacy problem in relaxation method‐analysis of asynchronous parallel processing
Authors: Kato Toshikazu , Wakimoto Koji , Inagaki Kosaku , Sakai Toshiyuki
Published: July 2007

In image pattern understanding, global and unspecific processing are required. Thus it is important to develop an asynchronous processing algorithm with high efficiency and MIMD type. This paper formulates and analyzes the determinacy problem on the newly introduced transformation model, as a basic theory for the asynchronous parallel processing algorithm for the pattern information processing. The major results are as follows: (i) a transformation model is introduced which can describe and analyze the mathematically parallel processing algorithm, into the content of the processing; (ii) the determinacy problem is formulated, arriving at a convergence theorem representing a sufficient condition; (iii) a discussion is made from the viewpoint of the determinacy problem on the possibility of asynchronous parallel processing of the relaxation method, which is already applied to the image processing. It is concluded that the asynchronous parallel processing is possible in the discrete and fuzzy relaxations, but is impossible in the linear and nonlinear stochastic relaxations.
Dynamic fault recovery in mesh‐connected parallel computers
Authors: Yokota Takashi , Amano Hideharu , Aiso Hideo
Published: July 2007

A trend in computer development aiming at high‐speed processing is high‐level parallel processing using a large number of processing elements. This scheme is becoming more realistic with the recent progress of VLSI technology. On the other hand, there arises a problem of how to cope with the generation of faults with the increased number of processing elements. A faulttolerant computer with multiple redundancy has been developed, but no method has been presented in the parallel computer environment whereby sufficient redundancy against fault can be provided, to recover from fault and to continue the computation without a system down. In general, completeness of data is lost by a fault. In the field of numerical computation, however, there are problems with less stringent requirement for completeness of data (e.g., in iterative solution of a system of equations). This paper discusses the case where such a problem is solved by a parallel computer with lattice topology. Three structural types are proposed for dynamic fault recovery during execution, mutual connection and the method of recovery. The result of evaluation by simulation is shown.