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In presenting this paper, the editorial board recognizes a new type of research tool which Mr. Smith has applied to police problems. In his article, the example cited has been reduced to the simplest terms, and to many experienced police officers the ultimate conclusion may seem obvious. The article is not presented with the idea of solving this particular simplified problem, but rather to call attention to the methods that are available and to arouse interest of our readers in the application of game theory to police problems. [ABSTRACT FROM AUTHOR]

The paper discusses the predictive ability and the items selected by the Gluecks research organization for their predictive devices are those arrived at by strict analytic multivariate techniques and represent findings that cannot be faulted by criticisms of the Glueck methodology. In 1950, Professor Sheldon Glueck and Dr. Eleanor T. Glueck published "Unraveling Juvenile Delinquency," a multidisciplinary, detailed comparison of 500 delinquent and 500 nondelinquent boys. In 1960, Professor Glueck, at the request of the editors of the "Journal of Criminal Law, Criminology and Police Science," prepared a paper for the issue to commemorate fifty years of publication of that Journal. The first of the criticisms is grounded in the fact that not all individualist used in Unraveling had complete observations on all. 400 items involved in the origin research. The reasons for these missing observations are varied. The nature of missing observations generally decides their impact on an experiment. There are three distinguishable types of missing observations: random, non-random, and indeterminate.

This paper looks at an area, which has proved very attractive to the stochastic modeler, that of social mobility. The author wants to survey it, not so much from the point of view of the mathematician striving to achieve the best fit he can to the data available, but more from the point of view of the sociologist who needs models which provide him with a theoretic framework which is readily translated into sociological concepts, and which contain assumptions to which the subject matter of the process, the individual actors, may reasonably be expected to adhere. This paper surveys a number of approaches to the finding of an appropriate mathematical model of social mobility. The author compares them with respect to the sociological theory of mobility, and concludes that the last model discussed is by far the most satisfactory from this point of view. One can anticipate a considerable gain in knowledge of social mobility when empirical research puts such a model to the test.

This paper provides information on theoretical sociology. By theoretical is meant "theory-using." Any type of statistical technique uses a model of nature, that is, a certain technique makes assumptions about reality and here the approach to theory construction is through the use of models. This is the orientation which regards each theoretical construction in levels, from the most abstract to the most empirical—and each theory construction should contain some of these levels. In this paper the concern will be with the use of an orientation involving the reduction of linear models of techniques which makes a first step towards this. The author also discusses rather more techniques. By following this course, the logic underpinning stochastic analytical techniques, and causal modeling techniques can be revealed. Also it is hoped to reveal how theoretical sociology can be synthesized with a branch of statistics.

The basic difference between what may be called curve fitting and what is here called mathematical modeling is that curve fitting is an ad hoc procedure while modeling focuses on the structure of relationships between variables, If one explains observations by curve fitting there is no reason to think that much more than a convenient summarization of data has occurred. Centroids or Gini coefficients for sets of data do not generally explain but summaries. However, coefficients and curves introduced to summaries data often do not remain as uninterpreted summary measures. Introductory material indicated that the paper was to deal with models that are both realistic enough to be of value in research and simple enough for parameters to be estimated. The authors believe that the models presented meet the realism criteria and believe little would be gained by debate on this in the paper. This indicates a need to examine the models to see what kinds of data are critical in distinguishing between the models and seeing that the considerations which could be said to be involved in designing a critical experiment are built into analysis or built into data collection so that there is discrimination between models where this is considered to be necessary or desirable.

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Social networks have been closely identified with graph theoretical models, which constitute their most familiar mode of representation. There are a number of such models which may embody symmetric, directed, or valued relationships. But the study of networks with valued linkages, using the natural formalization provided by the valued graph or digraph, has been impeded by a traditional lack of analytical machinery for dealing with valued structures. In this paper, we demonstrate the development and elaboration of formalizations for the central network concepts of reachability, joining, and connectedness through graph theoretical models of increasing complexity, culminating in their expression within a general model for valued structures. This model for valued (symmetric or directed) graphs, or vigraphs, provides a unified representation and matrix methodology for dealing with qualitative and quantitative structures, incorporates many existing methods as special cases, and suggests new applications. Some of the most interesting of these follow the recognition, consistent with the model, that the "values" assigned to network linkages may be sorts of entities other than numbers. [ABSTRACT FROM AUTHOR]

Whether the important conceptual advantages of blockmodeling can be practically utilized depends crucially upon the development of a satisfactory method for fitting blockmodels to data. Existing procedures suffer from several important limitations, principal among which is the lack of consensus on a measure of the goodness of fit of a blockmodel to the data it represents. in this paper I present a measure of goodness of fit, and an algorithm for finding blockmodels with maximal fit to data, that together render blockmodeling mathematically equivalent to regression analysis. To facilitate more detailed analyses, I also present measures of the degree to which individuals and their relations deviate from the overall pattern of the blockmodel, of the sharpness with which each cluster is defined, and of the distances between clusters. The algorithm and measures are applied to data concerning international trade in the Western Hemisphere in two different decades. [ABSTRACT FROM AUTHOR]

X-ray CT is a powerful tool in diagnosis, but it has not been developed to the stage where a clear tomography of the heart can be obtained Traditional CT devices re- quire approximately one second to acquire projection data even if the fastest machine is used. Due to this limitation, only very obscure cross-sections of the heart can be obtained. One solution to this difficulty is to apply a method by which the cross section can be reconstructed from a small number of projection data. This method of a small number of views limits the X-ray projections to a small number of directions and hence drastically decreases the data acquisition time, which in turn is effective in eliminating the blur that occurs due to the movement of the heart. This paper shows that the method of a small number of views satisfies the necessary and sufficient conditions required to obtain the solution and that the cross section is uniquely determined from a small number of projection data. The relation between the stability of the system and the number of projections and the number of reconstructed pixels is discussed. The effects of error in the projection data and the resolution of the X-ray detector on the reconstructed image are also discussed. A computer simulation is made to reconstruct an image of 128 × 128 pixels from the projections along two directions, verifying that complex cross sections with a large number of pixels can be reconstructed by the proposed method. [ABSTRACT FROM AUTHOR]

This paper presents segment matching as a correlation method in feature space. One way to improve the function of such a method is to increase the number of effective features. This paper proposes reciprocal feature extraction which simultaneously extracts and utilizes the stroke and concave space features, which have not been used simultaneously. The effectiveness of the method was verified by a recognition simulation for handwritten characters. [ABSTRACT FROM AUTHOR]

A recent tendency in the study of texture is the analysis based on mathematical models rather than the analysis of intuitively clear geometrical features. This type of study is advantageous in that a systematic and theoretical viewpoint can be provided to various kinds of related texture image processings. This paper considers the Gaussian-Markov random field as a mathematical model for the texture image, and applications of the theory are discussed for texture classification and boundary extraction of texture regions. The determination of parameters for the Markov model is discussed first. Then the distance between textures is defined using the model parameters and a method of texture classification is proposed. The extraction of the boundary between texture regions is formulated as a testing of the parameters of the Markov model, and a method of texture region partition is proposed using the statistical testing variable as the discrimination function for the texture boundary. A classification experiment was performed for texture images with 13 categories, each containing 23 patterns. A 100% rate of classification was obtained, indicating the effectiveness of the proposed classification method. The region partition experiment was performed for the patched texture image. The result of partition was satisfactory, indicating the effectiveness of the proposed boundary extraction method. [ABSTRACT FROM AUTHOR]

Geoffrion generalized the Benders' decomposition approach to a general class of `complicated' nonlinear optimization programs. The theoretical significance of the work in Reference 6 is significant, but its computational usefulness is rather limited, due to some serious computational difficulties inherent in the master problem. In this paper, we report on a simple technique to overcome and eliminate these difficulties. [ABSTRACT FROM AUTHOR]

This paper discusses the process assignment problem in the multiprocessor systems with communication contentions due to interprocess communication (IPCs). As a model for the multiprocessor system, a system is considered in which the processing elements (PEs) with local memory (LM) are connected through a communication network (CN). As a model for the distributed-type algorithm realized on such a system, a scheme is considered in which the process assigned on a PE is executed with IPC with other process. Based on these models, a problem is formulated where a set of processes is assigned on the multiprocessor system so that the overall processing time is minimized. Especially, for the problem where a single common bus is used as the CN and the processes are assumed as uniform, the optimum number of PEs is determined by introducing an approximation to the waiting time for the CN. The strict solution obtained by exhaustive search is compared with the approximate solution, and the validity of the approximate solution is evaluated. [ABSTRACT FROM AUTHOR]

This paper describes the fundamental concepts of the language processor generator MYLANG. The language machine in the classical automaton theory is used as the practical model. An algebra is introduced to handle the model easily, and a machine is constructed which can synthesize the model as an algebraic computation. As the algebra for the machine model, the semilinear algebra, i.e., an algebra close to the linear algebra on the language semiring is introduced. The hierarchy of the classes or machine models described by that algebra is examined. The machine model realizing the language processor generated by MYLANG and also realizing MYLANG itself arc located at the highest hierarchy, and are constructed in a hierarchical way from the machine models in the lower classes. First, the multiple sequential-transducer system is given as the syntax-directed translator. Then some additional mechanisms are combined with this class of machines. Its generator is given as the class of machines of that kind. Finally, the attributes are introduced, and the class of machines aimed at is given as the attributed syntax-directed translator. Its generator is specified as the class of machines of that kind. [ABSTRACT FROM AUTHOR]

In 1983, Holland, Laskey, and Leinhardt, using the ideas of Holland and Leinhardt, and Fienberg and Wasserman, introduced the notion of a stochastic blockmodel. The mathematics for stochastic a priori blockmodels, in which exogenous actor attribute data are used to partition actors independently of any statistical analysis of the available relational data, have been refined by several researchers and the resulting models used by many. Attempts to simultaneously partition actors and to perform relational data analyses using statistical methods that yield stochastic a posteriori blockmodels are still quite rare. In this paper, we discuss some old suggestions for producing such posterior blockmodels, and comment on other new suggestions based on multiple comparisons of model parameters, log-linear models for ordinal categorical data, and correspondence analysis. We also review measures for goodness-of-fit of a blockmodel, and we describe a natural approach to this problem using likelihood-ratio statistics generated from a popular model for relational data. [ABSTRACT FROM AUTHOR]

This paper presents a mathematical model for the biological oscillator with external stimulus such as cardiac pacemaker, and analyzes the synchronization phenomenon. The system to consider is described by a nonlinear differential equation. A simulation is made to examine the details of the synchronization and desynchronization. In the paper, the idea of Poincare's mapping is applied to examine the relation between the invariant set on the topological plane and the synchronization. As a typical example of arrhythmic phenomenon, the amplitude and the frequency of the external stimulus is varied to determine the entrained region for the 1/2-haraonic oscillation. The transition among various synchronization patterns appearing in this region can be accounted for by the spatial relations among the stable and the unstable manifolds. It is shown as a result that when the locations of the stable and unstable manifolds are interchanged, they intersect, leading to the homoclinic or heteroclinic points. A random rhythm has been observed in the escape phenomenon of the cardiac pacemaker, and the chaotic random oscillation is also derived from the mathematical model. It is shown that the origin of the chaos is related to the Heteroclinic and homoclinic structures. [ABSTRACT FROM AUTHOR]

In this paper, a computational scheme of determination of the average lime constant for diffusion processes by means of the finite element method has been presented. The algorithm is based on the software package for stationary problems and allows analysis of both two- and three-dimensional problems. [ABSTRACT FROM AUTHOR]

The term-rewriting system is of a recent concern, since there can be various applications, including the execution mechanism for the programming language based on the equality. However, in Its application there must be a normalizing reduction strategy, which ensures that the normal form can always be reached if the given term has a normal form. Huet and Lévy proposed the call-by-need strategy as a normalizing reduction strategy for unambiguous linear term-rewriting systems. This paper extends their result to the case containing ambiguity. A sufficient condition is shown first for the call-by-need in a linear term-rewriting system containing ambiguity to be a normalizing reduction strategy. The condition properly includes the result of Huet and Lévy. Then considering an arbitrary linear term-rewriting system, in which the call-by-need is a normalizing reduction strategy, a condition is presented under which a new rewriting rule can be added, while retaining the properties. Combining the result with the previous result, a wider class of ambiguous team-rewriting system is obtained in which the call-by-need is a normalizing reduction strategy. [ABSTRACT FROM AUTHOR]

In this paper is shown the effect of plate thickness on the spectral properties of the stiffness matrix which is obtained from finite element representation. The results confirm the very stiff properties associated with the strata energy based on Reissner and Mindlin theories in the case of thin plates. On the other hand, the Bergan and Wang approach converges to exactly the classical thin plate solution as the thickness decreases. [ABSTRACT FROM AUTHOR]

This paper presents a brief survey of some theoretical results concerning the motion of a viscous incompressible fluid in a domain containing a periodically perforated wall (or sieve). By studying a model problem, and using homogenization theory, the paper gives a complete description of the asymptotic behaviour of this kind of fluid flow as the sieve becomes finer and finer. [ABSTRACT FROM AUTHOR]

This paper describes numerical experiments made to investigate the stability of some time-stepping algorithms applied to the equation ü + P(u) = 0 representing a nonlinear elastic spring. These algorithms would be unconditionally stable when applied to linear problems, but here they may be only conditionally stable. Ways of improving the stability are demonstrated; the effect of linearization is also investigated. [ABSTRACT FROM AUTHOR]

The paper describes the results of computer simulations of behavioral contagion in the realm of public opinion. Using threshold models to describe how and why some people assert opinions and others do not, the paper argues that to better describe the dynamics of opinion assertion and quiescence the model must be able to account for the fact that different individuals differ in the importance they place on the actions of others, and in the networks in which they are embedded. The paper reports on simulations incorporating these aspects into the model, yielding an improved representation of public opinion dynamics. Further, the incorporation of networks and weighting systems in the model alleviates one of the problematic features of the simple threshold models described by Granovetter, namely that certain individuals play unrealistically key roles in the contagion process. When networks are accounted for, the threshold formulation is less likely to make the group dynamic so dependent upon the behaviors of specific individuals. [ABSTRACT FROM AUTHOR]

By modeling the heat transfer in and around a hot-rolled bar, the temperature distribution in the bar can be predicted at any stage of the hot rolling process. Knowledge of these temperatures is useful when the process is to be optimized. This paper presents a finite difference simulation of the heath transfer and resulting temperature distribution. The numerical accounts for thermal radiation from the bar, and the mill rolls and manipulators. Measured values for convective heat transfer coefficients are used at the boundaries. The following effects are also accounted for in the procedure: deformation of the bar during rolling, titling the bar between passes through a mill, cropping the contraction resulting from loses, predicted and measured temperature correlate favorably. [ABSTRACT FROM AUTHOR]

This paper argues that the quadratic assignment procedure (QAP) is superior to OLS for testing hypotheses in both simple and multiple regression models based on dyadic data, such as found in network analysis. A model of autocorrelation is proposed that is consistent with the assumptions of dyadic data Results of Monte Carlo simulations indicate that OLS analysis is statistically biased, with the degree of bias varying as a function of the amount of structural autocorrelation. On the other hand, the simulations demonstrate that QAP is relatively unbiased. The Sampson data are used to illustrate the QAP multiple regression procedure and a general method of testing whether the results are statistically biased. [ABSTRACT FROM AUTHOR]

This article reviews a paper by A. Efimov published in this issue of Soviet Sociology which reports on several mathematical models of the evolution of elites that Efimov and his colleagues developed in the 1970s. The paper deals with an extremely important issue, one only known to a small number of specialists. The present author notes that the problems of organization theory are extremely timely today, since people are in fact experiencing a period of restructuring of the entire organizational structure. Hence the use of the ideas and methods of organizational theory may be of perceptible use to the efforts being undertaken in this area. Unfortunately, broad circles of specialists do not know of the existence of organizational science, or of the fundamental knowledge it has accumulated. But the present author is convinced that the future of socialist society depends on the development of organization theory and the ability to make use of its conclusions, since this theory is capable of helping Soviets to make use of Soviet Union's resources and its intellectual and moral potential. The present author thinks it is appropriate to make a small digression to organization theory and to begin this article with a discussion of its rudiments. At the same time, the present author tries to show the place of Efimov's paper in the development of this theory.

This article reviews a paper by A. Efimov published in this issue of Soviet Sociology which reports on several mathematical models of the evolution of elites that Efimov and his colleagues developed in the 1970s. The present author notes that one reads Efimov's paper with unabating interest, so unique in his approach to the extremely important problem of bureaucracy. According to the present author, the use of mathematical model of elite groups in fact reveals new aspects of a social phenomenon that has become a grave impediment to development of Soviet society. At the philosophical level, Efimov's approach can be supported by dint of the fact that the use of the analogy method is more and more coming into its own in the most diverse domains of theory and practice. According to the present author, the somewhat dispassionate academic tone of the first pages of the paper proved to be merely a means for initiating the reader into a range of urgent problems whose analysis requires a maximum objectivity and rigor in its conclusions. In the present author's view, Efimov's greatest achievement is to combine a rigorously scientific approach with a profound personal interest in the problem being discussed.

This paper describes an automatic diagram input system which reads the handwritten piping and instrument diagram and recognizes the symbol, character, and line drawn on the diagram. The object is a handwritten diagram which is easily understandable by the knowledge of the designer under a very mild constraint. The symbols which are the object of recognition are of more than 200 kinds of various sizes. In addition, a large symbol with unspecified shape may be drawn, and there can be various kinds of lines. To cope with such complex diagrams containing a large amount of handwriting distortions, various diagram processing techniques are proposed. Examples are vector representation with a high accuracy, shaping of various distortions, and the two-stage segmentation, where line, symbol and character are separated hierarchically from the vectorized figure. Other examples are the symbol recognition combining a decision tree and pattern matching, and recognition dictionary based on automatic generation of distorted patterns. The developed diagram input system is a flexible system, in which new symbols can be additionally registered, and complex handwritten diagrams can be recognized. A test was made for the system using the actually written design diagrams. The result indicated a practically satisfactory performance, where the processing time is 3 to 8 mm for an A3 sized diagram by a large-scale computer and the recognition rate is above 95 percent. [ABSTRACT FROM AUTHOR]

Edge detection can be executed by computer at a high speed and thus lends itself to region extraction. However, the edges detected from most images are imperfect due to noise and broken edges. This paper presented an edge-based region segmentation algorithm using a global measurement called degree of centrality. Methods of computing the degree of centrality from the input image, analyzing its distribution and detecting gaps between edges will be described. The spatial relationship of disjoint boundaries and pseudoregions will be analyzed to determine region splitting and/or merging. The performance of the proposed algorithm is demonstrated via experiment using images of an indoor scene. Advantages of this algorithm include its simple work-flow, and its ability to perform feature extraction while performing region segmentation. [ABSTRACT FROM AUTHOR]

This paper proposes a basic model for the self-organization of the recognition cell group in the nerve field. The model is composed of nerve cell layers with mutual lateral inhibition. Also described is the condition for the self-organization of the recognition cell groups for the n-dimensional input and, based on that condition, the properties of the model are discussed. Then the behavior of the model is verified through computer simulation. As a result, the following observations are made. When a certain condition is satisfied, recognition cells are formed in a group. These cells respond only to the particular set of input patterns. By varying the training parameters, the recognition cell group is formed depending on the similarity between input patterns. For highly similar patterns, the recognition cell groups are formed in nearby locations in the nerve field. The recognition cell group is formed according to the frequency of the input pattern and its norm. [ABSTRACT FROM AUTHOR]

The paper describes the application of a numerical model to the prediction of seasonal temperature and moisture content changes in the ground. The results are compared with measured values taken over a two year period at the site of a monitored field experiment. Blind predications have been carried out on the basis of assumed material parameters. It is concluded that the analysis is largely capable of modelling the phenomena observed. Certain limitations are, however, exposed. [ABSTRACT FROM AUTHOR]

This paper describes a method which generates all elements of a Cartesian product of two sets, using the shuffle-exchange network. Often, processing appears which requires all elements of the Cartesian pros duct in various fields in computer science as well as set manipulations in mathematics. Consequently, this operation can be considered to be one of the most fundamental. In this paper, the Cartesian product of two sets with N/2 elements is generated by an N-input, N/2-stage shuffle-exchange network by assigning the switching element to each element of the Cartesian product. The experimental derivation of the realization method and the result of the experiment are described. In the derivation of the realization method, some properties of the shuffle-exchange network are discussed. In the realization of the Cartesian product by an N/2-stage shuffle-exchange network, no redundant switching element is used. Consequently, the method shown in this paper is optimal. [ABSTRACT FROM AUTHOR]

In the usual P-ary number digit for the addition and subtraction of two numbers (operands), 0, 1, 2, ..., ⌜p-1⌟ are employed. In the minimum redundant P-ary representation, &Ibar; is further used, and the addition or subtraction can be performed in a constant time independent of the number of operand digits (P∈{2, 3, 4, ···}). This paper extends this property. First, a high-speed addition-subtraction algorithm is discussed. It can execute the addition and subtraction of L(∈{2, 3, ···, P}) operands in a constant time independent of n and L. The following property is shown as the result. Using the redundant P-ary representation (called K-redundant P-ary representation), where &Kbar;, ..., &2bar;, &1bar;, 0, 1, 2, ..., ⌜p-1⌟ can be used as the digit, the minimum necessary value for K is L - 1, and the desired algorithm can be found if L - 1≦K(≦P-1). The presented algorithm can easily be extended to an algorithm which can execute the addition and subtraction of L operands in a constant time independent of it, where L is an arbitrary number such that P+1≦L. It is shown that if f(x)= ┌logpx┐+1 (┌y┐ is the minimum integer not less than y), the computation time T is O(logα), where α is the minimum number of operations for the function f( ) satisfying f(f(···f(f(L))···))≦P; α increases stepwise with L. When P is increased, T decreases, and the range of L, for which T is constant, increases exponentially. Using the proposed algorithm, one can expect that a multi-input high-speed adder-subtractor can be constructed. Various kinds of high-speed data processings can be realized, including the multiplication, where the shifted partial products are added. [ABSTRACT FROM AUTHOR]

This paper applies the dynamic programming (DP) matching to the border extraction from the dynamic echocardiogram of the heart along the short axis. The method is based on the DP matching for the two-dimensional static image. The sampled values are stabilized by the integration by time, and the border features are emphasized by the differentiation in time. The matching is made using the spatial derivative intensity, the spatial derivative direction, and the time derivative intensity. The use of the continuity constraint along the time axis in the matching is discussed. Utilizing the property of the object that the motion is periodic within a certain range, the point of motion is determined from the sum of the time derivative over a pulsatile period. and the result is utilized in the matching constraint. [ABSTRACT FROM AUTHOR]

This paper discusses the basic properties of the probabilistic push-down automaton (PPDA). Intuitively speaking, PPDA is obtained by adding a probabilistic property to the nondeterministic transition of the nondeterministic push-dawn automaton (NPDA). According to the property of the error in the accepting condition, PPDA is classified into a two-sided error PPDA, a one-sided error PPDA, and bounded error PPDA. Moreover, the acception error is considered not only for 1/2, but also for an arbitrary cut-point, to discuss the relations among classes of languages. Major results are as follows. The class of languages accepted by bounded error PPDA is not the same as that accepted by NPDA. In the case of two-sided error PPDA and the bounded error PPDA, the class of acceptable languages does not depend on the cut-point. In the case of a one-sided PPDA, the class of acceptable languages depends to some extent on the cut-point. In other words, there exists an infinite hierarchy. Kolmogorov complexity is used in the proof of the major theorem. [ABSTRACT FROM AUTHOR]

An individual's "status" is the position in a social network, which is usefuly modeled by the mathematical properties of directed graphs. Katz (1953) argued that an index of status based on "who chooses whom" should also include information on the status of the choosers. This recursive concept os status was adapted by Sade (1972), who used the sum of inward directed paths as a measure of centrality to distinguish the position of individual monkeys in a grooming network. Sade et al. (1988) used the same measure to describe the progression through time of the statuses of a set of male monkeys. These studies were limited by the, perceived computational difficulties in finding paths longer than 3-paths. Although ad hoc formulae for up to 6-paths were available from Ross and Harary (1952) and a general algorithm was known from Parthasarathy (1964) the methods were cumbersome and impractical to apply to large networks. The present paper makes use of a simple counting algorithm to find the n-paths in a binary matrix. The characteristics of centrality statuses in the grooming network are then describing using paths of up to maximum length, thus avoiding the limitations of the earlier studies. [ABSTRACT FROM AUTHOR]

This paper builds a computer simulation model of organizational innovativeness. The components of the model are the characteristics of the organization's employees, the new practices under consideration, and the structure and shape of the organization itself. The simulation results indicate that innovativeness is most sensitive to the level of employee dissatisfaction with status quo policies and to the distribution of organizational authority. The most innovative organizations are those in which employees are most dissatisfied with existing policies and the authority structure is highly centralized. Other employee, innovation, and organizational characteristics have little or no effect on innovativeness. [ABSTRACT FROM AUTHOR]

The problems with recent approaches in qualitative and causal reasoning are that: (1) in qualitative modeling, they do not discuss on what types of mathematical models their qualitative equations should be based. This allows the misuse of static models for the qualitative equations to discuss changes in the transient state; and (2) they do not define causality on their qualitative model. This paper defines the "inherent causality" which requires "time reference." With this causality, causal reasoning is carried out by verifying that any change is made by the causality. The verification is done by consumption of dt = + for each step. To make such causal reasoning possible, the base model (i.e., the dynamical model which describes causality from what makes the change to what is changed) is selected carefully. Also, the qualitative simulation algorithm utilizing the inherent causality is developed. The power of the causality and simulation algorithm is demonstrated on the examples of a buffer tank. AQUA, a knowledge acquisition tool for process diagnosis domain, is implemented using the qualitative simulation. AQUA uses the qualitative simulation in generating fault-syndrome associations. [ABSTRACT FROM AUTHOR]

This paper proposes a new model for the Mean visual motion perception mechanism. The model can detect in a pertinent way the direction of motion of the object, even if the object moves in a background with a complex luminance distribution. When the object has such a background, the information concerning the object motion inevitably contains the disturbances due to the luminance distribution of the background. In the model for the motion perception mechanism up to now, however, this point has not been considered at all. This paper takes the view that the perception of the motion with such a background is essential in understanding the motion perception mechanism. Psychophysical experiments are presented to provide an insight into the motion perception mechanism for movement with a background. The result of the experiment suggests that there exist two processing stages in the motion perception. The first stage is to fix the position of the moving object at a particular position in the visual field, and the second stage is to detect the movement of that position. Using a spatiotemporal filter simulating the receptive field, a model composed of two such stages is constructed. A computer simulation is conducted to examine the validity of the method, and a result agreeing well with the human psychophysical characteristic is obtained. [ABSTRACT FROM AUTHOR]

Based on the context-free tree grammar (CFTC) proposed by W. C. Rounds [7J, the concept of pushdown tree automata (PDTA) was newly introduced. Such a PDTA was a top-down PDTA. By contrast, it is desired to introduce its dual concept, i.e., a bottom-up PDTA. With such a background, this paper proposes a new concept of bottom-up PDTA and it is shown that one of the fundamental properties of the pushdown automaton (PDA) such as the final state acceptance, equivalent to the empty stack acceptance, is also applicable to the bottom-up PDTA. Next, we show that the tree language accepted by the bottom-up PDTA is always accepted by a single-state bottom-up PDTA. It is shown also that the tree language accepted by the single-state bottom-up PDTA is accepted by the single-state linear stack bottom-up PDTA, where the stack structure is restricted to be linear. This paper discusses only the fundamental properties of the bottom-up PDTA. We hope to give a basis for the theoretical development of tree language and related fields. [ABSTRACT FROM AUTHOR]

The parallel computer based on the parallel operation of a large number of CPU is now available as a means of realizing a high-speed computer. Especially, the loosely coupled parallel computer is considered to be interesting as a tool for realizing the neural network model, since it is related closely to the idea of the group of neurons. In such a computer, the efficiency is affected greatly by the assignment of functions to CPU. From such a viewpoint, this paper discusses the realization of a high-speed neural network model on a loosely coupled parallel computer. The neocognitron is considered as the neural network model; and the structure of the model, together with the feasibility of parallel operation, is discussed. By utilizing the feature of the loosely coupled parallel computer with hypercubic connection, an efficient CPU assignment is considered. Based on those results, a recognition system for handwritten numerals by the neocognitron is realized on the parallel computer NCUBE, and the recognition speed of eight characters/s is realized. Finally, the data transfer method and the load balancing among CPU are discussed, aiming at the realization of an exhaustive connection, which is required, in general, in the neural network model. [ABSTRACT FROM AUTHOR]

This paper discusses the problem of object identification based on spatially sparse uncertain information. First, it is assumed that the sensor information is composed of two kinds of information, i.e., the geometrical parameter distribution and the decision tree. The description format for the uncertain sensor information is defined. Then a method is presented where the set of uncertain sensor information obtained by the measurement of the object is combined (fusion), and the match between the object and the model is examined. Finally, the case of measurement of the two-dimensional figure by the sparse shape sensor is considered. The process of fusion is demonstrated and the usefulness of the proposed method is shown by a matching experiment. In the proposed method, art object identification procedure is employed where the information obtained from several sensors is described as geometrical parameters together with their error distributions, and the match to the model is examined by combining those parameters. The information, for which more than one decision tree interpretation is possible, is described as the basic probability of the Dempster-Shafer theory. The parameters are fused for each interpretation, and the reliability of the result of fusion is estimated by the combination rule. As a simulation experiment, the case with the tactile sensor in contact with a column object is considered, and the object identification process is demonstrated. [ABSTRACT FROM AUTHOR]

To extract geometric features by parallel operation, a directional erosion/dilation operation method by unifying directional feature field and directional parallel operation was proposed and its effectiveness was verified by application to the extraction of buildings, roads, hatching regions, and character regions from a topographical map. This paper extends this method further and proposes the "multiangled parallelism matching method" for extracting higher-order features (models of shapes) composed of relation among lines, The input is represented by "directional planes." The model of a shape is given as a "direction" at each "evaluation point" and "displacement" from the previous evaluation point to the evaluation point. Matching is performed by repeating parallel operation for the entire plane of "translation" of a "counter plane" storing evaluated quantity and "addition" of the plan of input direction into the counter plane. The MAP matching method has a feature that the result of exhaustive matching for directional elastic templates is obtained as consecutive evaluated quantities by parallel operation. The exhaustive template matching, Hough transform, and DP matching method are compared, and the results of recognition experiments of echocardiograms of the heart are shown. [ABSTRACT FROM AUTHOR]

This paper proposes a new parallel-hierarchical neural network model to enable motor learning for simultaneous control of both trajectory and force, by integrating Hogan's control method and the author's previous neural network control model using a feedback-error-learning scheme. Furthermore, two hierarchical control laws which apply to the model are derived by using the Moore-Penrose pseudo-inverse matrix: one is related to the minimum muscle-tension-change trajectory; and the other is related to the minimum motor-command-change trajectory. The human arm is redundant at the dynamics level since joint torque is generated by agonist and antagonist muscles. Therefore, acquisition of the inverse model is an ill-posed problem. However, the combination of these control laws and feedback-error-learning resolves the ill-posed problem. Finally, the efficiency of the parallel-hierarchical neural network model is shown by learning experiments using an artificial muscle arm and computer simulations. [ABSTRACT FROM AUTHOR]

In this paper a practical improved mode superposition method for linear damped systems is suggested. In this method, a recurrence formula, an exact answer can be obtained in terms of low-degree modal information to fourth-degree accuracy. [ABSTRACT FROM AUTHOR]

This paper proposes a speaker adaptation method for speech recognition based on the discrete hidden Markov models (HMM), especially the fenonic Markov model, which is a framewise model. The method consists largely of two parts--the adaptation of the vector quantization codebook and the adaptation of Markov models. The former employs a method which is based on the difference between the feature parameter distributions of the training speech and the word baseform as the basis for the adaptation, where the two are divided into N segments on the time axis. The latter employs a method based on a linear mapping, which is estimated from the matching between the quantized training speech and the word baseform. In this study, a recognition experiment was executed using 150 words with high similarities. Using the speech in which all object words are uttered ten times by a male, the codebook and the Markov models are estimated as the basis for the adaptation. Then the adaptation training is executed for seven males and four females by uttering once 25 words in the object vocabulary. The avenge error rate, i.e., 25.0 and 45.2 percent, respectively, for the males and females, is improved to 4.1 and 7.8 percent. Thus, the usefulness of the proposed method is demonstrated. [ABSTRACT FROM AUTHOR]

This paper formalizes the operation of a monitor-one of the fundamental models for concurrent processing-in a framework which is an extension of CCS (the calculus of communication systems) proposed by Milner. The purpose of this paper is to define the mutual exclusion and synchronization control of a monitor based on formal computation mechanisms and to provide a basis for the verification of the properties of a monitor as a concurrent program. For this purpose, a programming language which directly represents the execution mechanism of the monitor and the syntactical translation from that language to a CCS expression are defined. Through this translation, the mutual exclusion of the monitor procedure as well as synchronization control by means of the conditional variable-the essential features of the monitor-are for- malized within the CCS framework. As a result, by adopting an observable equivalence relation between the semantics of CCS operational expressions of the seman-semantics of operation of the model, we show that it is possible to demonstrate the abstraction mechanism of the model. [ABSTRACT FROM AUTHOR]

Some of the serious factors that deteriorate the reconstructed image in MBA are the static field inhomogeneity and the motion of the object (patient) during data acquisition. To prevent the deterioration of the reconstructed image by such factors, a priori knowledge about the static field inhomogeneity and the motion of the patient is required. This paper considers the ultrahigh-speed imaging using the time-varying gradient magnetic field and proposes a method which estimates the static field inhomogeneity and the patient motion from the measured FLD signal and the a priori knowledge about the region of existence for the patient. When the patient is constrained within & certain region in the field of view, a strong constraint called consistency condition essentially is imposed on the functional form of the measured FID signal. In the proposed method, a simple mathematical model is applied to the static field inhomogeneity and the patient motion and the model parameters are estimated so that the consistency condition is satisfied. By the proposed method of estimation, the artifact due to the static field inhomogeneity and the patient motion can be reduced without performing an additional measurement. [ABSTRACT FROM AUTHOR]

This paper proposes a novel method for acquiring a shape model from shape samples of the same class. In conventional approaches, a priori knowledge and unique parts segmentation are needed because they perform generalization of predefined symbolic concepts. Moreover, they cannot form visual shape models because the model is represented as parts and parts relationships in the form of graph models such as semantic networks and multilevel graphs. The approach herein can directly acquire a visual model from a few samples without a priori knowledge because it is based on the generalization of multiscale convex/concave structure of a class of shapes. First, an optimal scale convex/concave segment structure common to shape samples using a multiscale segment matching method is extracted. Then the extracted segments are integrated to create generalized shapes. Finally, an importance measure based on the optimal scale is assigned to each convex/concave segment of the generalized shapes. That is, the proposed shape models consist of conjunctive descriptions as for the convex/concave segment structures, disjunctive descriptions as for the convex/concave segment forms, and the importance measure assigned to each segment of the shape model. A shape recognition method using the acquired models also is presented. Experimental results show the usefulness of the proposed method. [ABSTRACT FROM AUTHOR]

The job for which processing is determined only in the course of execution is called the unschedulable job. When an unschedulable job is to be executed in a parallel processing system, it is not predetermined when the communication between processors arises, and synchronization among processors is a serious problem. This paper considers the mathematical theory for the existence of interprocessor communication and the transmission time in the execution of the unschedulable job. The message-passing scheme is extended, considering the message transmission probability and the indeterminate aspects of the transmission time. Then the advance processing control is considered, which helps the synchronization among processors in the execution of the unschedulable job, and the overhead is theoretically analyzed. The condition for the task assignment to the processors is derived so that the deterioration of the processing speed due to the overhead can be minimized. [ABSTRACT FROM AUTHOR]