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Volume 15, Issue 3
Displaying 1-24 of 24 articles from this issue
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Yoshiteru NAKAMORI, Saburo IKEDA, Yoshikazu SAWARAGI1979 Volume 15 Issue 3 Pages 277-283
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAn approach to the optimal allocation of sensors in a class of distributed parameter systems is considered. Since it is technically impossible to observe the system state at overall spatial domain and all real systems are subjected to stochastic disturbances, it is necessary to choose the optimal location of sensors in order to obtain the best state estimates. The measurement optimization based on the filtering theory, in which the linear system, the Gaussian noise processes, and the quadratic cost are considered, can be done a priori by solving an optimal control problem with the Riccati equation. Although the non-linearlity of the Riccati equation makes the problem analitically intractable, the necessary conditions of optimality have been derived and some simple numerical examples have been reported by various authors. The determination of optimal locations in the multi-dimensional spatial domain, however, requires much calculation time and the prior limitation of allowable measurement points. In this paper an alternative approach to allocate sensors is considered by applying the concepts of the Monte-Carlo stratified sampling method to our problem. Approximate measurement systems for the spatial continuous and the spatial averaging types of measurements are constructed by optimally allocating a give number of sensors to the prespecified strata so that the information may be preserved as much as possible. This approach cannot make the precise determination of each sensor's location, but provides an effectual method to allocate many sensors in a multi-dimensional spatial domain.View full abstractDownload PDF (900K) -
Takashi SUZUKI, Takumi NAKAMURA1979 Volume 15 Issue 3 Pages 284-290
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper presents a discrete model reference adaptive control scheme for a class of multiinput multi-output linear plants, based on the concept of augmented error. In this scheme the output error between the reference model and the plant is transformed into an augmented error expressed by a simple equation, by introducing an auxiliary signal vector and adjustable parameter matrices. Applying Liapunov's direct method to the augmented error equation yields a parameter-adjustment law which ensures an asymptotic stability of the augmented error vector. Corresponding to this adjustment law, the plant input and the auxiliary signal are synthesized so as to ensure that the output error vector between the model and the plant approaches zero asymptotically. The derived adaptive control algorithm can be implemented by using only available input-output data of the plant. The effectiveness of the proposed scheme is demonstrated by the computer simulations carried out for a two-input two-output linear plant.View full abstractDownload PDF (820K) -
Toshio NOMURA, Katsuhisa FURUTA1979 Volume 15 Issue 3 Pages 291-297
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSPolynomial state-affine systems described by {x(k+1)=(A+∑ri=1ui(k)Ni)x(k)+∑ri=1ui(k)Biy(k)=Cx(k) can be considered to constitute an important class of nonlinear discrete-time systems, which corresponds to a class of bilinear systems in continuous-time systems. The purpose of this paper is to investigate the criteria for span-reachability and distinguishability of the polynomial state-affine systems, and to develop an algorithm for the minimal realization by extensively using the generalized Hankel matrix, which was originally introduced by Isidori for the minimal realization of bilinear, systems. Further application of this algorithm is attempted to realize a particular class of systems whose input/output maps can be expressed in polynomial forms of input variables.View full abstractDownload PDF (890K) -
Yasumichi HASEGAWA, Tsuyoshi MATSUO1979 Volume 15 Issue 3 Pages 298-305
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThe realization theory of discrete time linear representation systems is established. We have already established the realization theory of discrete and continuous time dynamical systems in (1) and (2). The main theorems in (1) and (2) are as follows. For any causal input/output map A# of a Black-Box, there are canonical (reachable & distinguishable) dynamical systems which realize A#. A dynamical system δ is a collection of Ω-module (X, φ), an initial state x0∈X, and a readout map h: X→Y. If δ1 and δ2 are canonical realization of A#, then there is a unique dynamical system isomorphism T: δ1→δ2.
In this paper, we restrict the set Y of output values to a linear space over a field K, and consider only a subclass of dynamical systems, i.e., the class of dynamical systems δ=((X, δ), x0, h) such that (X, φ) is a linear Ω-module, x0∈X, and h: X→Y is a linear map. Such dynamical systems δ are called linear representation systems (L. R. S.). We define that δ is quasi-reachable if the linear hull of the reachable set from x0 is X.
The main theorems state that for any causal (non-linear) input/output map, there exist canonical (quasi-reachable & distinguishable) L.R.S. realizations, and that if δ1 and δ2 are canonical L.R.S. realizations, then there exists a unique L.R.S. isomorphism T: δ1→δ2. To prove the theorems, we have converted a L.R.S. δ=((X, φ), x0, h) to a sophisticated L.R.S. Σ=((X, φ), G, H), where (X, φ) is an A(Ω)-module, G: (A(Ω), _??_)→(X, φ) is a linear input map, and H: (X, φ)→(F(Ω, Y), Sl) is a linear observation map.View full abstractDownload PDF (1322K) -
Masato INAGAKI, Yasuyuki FUNAHASHI1979 Volume 15 Issue 3 Pages 306-312
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper conciders an inhomogeneous bilinear realization in case of unknown initial state. This problem was first studied by Tarn and Nonoyama. However, their existence condition of inhomogeneous realization is found to be insufficient. Hence, a complete condition is given in this paper.
And their condition of inhomogeneous bilinear realization depends on the factorization of the generalized Hankel matrix into specific factors. This is difficult to check. In this paper, the criteria for judging whether a given matrix has the specific factorization or not are obtained. As a result an existence condition of inhomogeneous bilinear realization is given. The condition is independent of the specific factorization, hence is easy to use for practical purposes.View full abstractDownload PDF (926K) -
Shin-ichi KAMIYAMA1979 Volume 15 Issue 3 Pages 313-319
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, the reduced systems whose controllability, stabilizability and right invertibility coincide with those of the original system are defined. A reduction algorithm for constructing the reduced systems and a new method for constructing a minimal order right inverse system by using the reduced systems are presented. Furthermore, a necessary and sufficient condition for the existence of a stable right inverse system is given, and it is shown that no state feedback compensation is possible for the original system if the compensated system is to have a stable right inverse system. Finally, it is shown that the reduction algorithm presented here is equivalent to transforming the original system into a standard form, and esveral structural properties of the system are clarified out of the standard form.View full abstractDownload PDF (800K) -
Shigenori MIZUGUCHI, Ryozaburo TAGAWA1979 Volume 15 Issue 3 Pages 320-325
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a sequential procedure for estimating frequency responses of linear discrete-time systems, the output of which is contaminated with a stationary noise having an unknown mean value.
A mathematical model of the system is formulated by setting a situation that the noisy steady-state output to a composite sinusoidal input is observed. Applying the least-squares approach to the model, the values of real and imaginary parts of the frequency response of the system are estimated simultaneously at the frequencies corresponding to the components of the input signal. A sequential procedure is given for on-line implementation. In it the estimates are updated every M samples, where M is the number of the samples in one period of the input signal.
It is shown that the estimates are unbiased and consistent under the following two conditions even if the mean of the noise is unknown:
1) the frequencies of the input signal are integral multiples of the basic frequency 2π/N, where N is the number of the samples in the measurement time,
2) the measurement time is integral multiple of the period of the input signal.
An example of digital simulation is given also to show the usefulness of the proposed procedure.View full abstractDownload PDF (665K) -
Toshio YOSHIMURA, Katsunobu KONISHI, Takashi SOEDA1979 Volume 15 Issue 3 Pages 326-331
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with the identification problem of a dynamic system, in which a nonlinear characteristics is followed by a Z-transformed transfer function of a linear dynamic part. The output of the nonlinear characteristics depends upon the input signal and the changing direction of it, and the output of the system is measured in contamination with a random noise. The identification technique by the model reference adaptive approach is applied to the system after approximating the nonlinear characteristics by a set of known functions multiplied by unknown parameters. A compensation element to guarantee the stability of the obtained identifier is designed, and an independent random sequence uniformly distributed is selected as an input signal to assure the convergence of the unkown parameter estimates to the exact values. Numerical results obtained from digital simulation in a simple nonlinear system show that the proposed method gives significant improvement to the identification of the nonlinear system.View full abstractDownload PDF (800K) -
Yoshimi MONDEN, Suguru ARIMOTO1979 Volume 15 Issue 3 Pages 332-338
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper proposes a stationarity criterion for an autoregressive representation of the multivariable stationary stochastic process.
By using the properties of symmetrizable matrices, it is shown that block Toeplitz matrix of a normal equation, prediction error matrices and reflection coefficient matrices are closely related to each other.
By applying Lyapunov's theorem to block companion matrices, the stepwise stationarity criterion for the generalized Levinson's method is derived and its relation to the positive definiteness of the prediction error matrices is made clear.
Though Rouché's theorem, on the basis of Szegö's orthogonal polynomials, plays an important role in fitting a single channel autoregression, the theorem's extension to a multivariate version has never been attempted. In this paper Rouché's theorem is generalized to polynomial matrices and is applied directly to the recursion equations of the orthogonal polynomial matrices to test the stationarity of multivariate autoregression. The author's criteria may have an application in analyzing multiple input-output systems in the frequency domain.View full abstractDownload PDF (831K) -
Yoshimasa KAMEYAMA, Hayatoshi SAYAMA, Katsumi INABA, Takashi MURAKAMI1979 Volume 15 Issue 3 Pages 339-344
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper we consider how the choice of initical values of Lagrange multipliers and penalty parameter affects the convergence property of the multiplier method for solving constrained nonlinear programming problems.
We point out that if we choose a sufficiently large penalty parameter, the condition number of the principal Hessian matrix of the multiplier function will become clearly different depending on whether we choose the Lagrange multiplier to be larger or smaller than the optimal value σ*.
For the purpose of applying effectively this feature of multiplier function, we propose a multiplier method taking the condition number into account and choosing an initical value of the Lagrange multiplier to be sufficiently greater than σ*.
By a numerical example, we compare the convergence characteristics of the proposed multiplier method, in which we consider the condition number, with those of the usual multiplier method.View full abstractDownload PDF (797K) -
Case of Observation Noise with Random StatisticsYoshiki TAKEUCHI, Hajime AKASHI1979 Volume 15 Issue 3 Pages 345-352
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAn algorithm of minimal variance state estimation is shown for a class of continuous-time linear stochastic systems with coefficients depending on a finite state Markov chain. The class of the systems considered in this paper is more general than that of problems previously treated, in that the statistics of the observation noise can be also depend on the Markov chain. The minimal variance state estimate by using continuous-time observations is not feasible because the mathematical measurability of the noise covariance is guranteed by the differential operation which can not be realized in finite steps. For this reason, the available observations are assumed to be sampled from a continuous-time process in a short period on a finite set of time points. Except for a Bayesian type formula for the a posteriori probabilities of the Markov chain, the algorithm consists of a set of difference equations similar to stochastic differential equations in the case of continuous-time observations. A numerical example is shown to illustrate the performance of the algorithm.View full abstractDownload PDF (984K) -
Shinji ARAYA, Satoru SONE1979 Volume 15 Issue 3 Pages 353-359
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn the railway system, passengers are transported intermittently from one station to another by trains which are operated on a time schedule. The passengers flow is considered as a dynamic one, because both the train schedule and the traffic demands vary as a function of time. From the user's point of view, it is necessary to estimate the passengers flow to evaluate the train schedule quantitatively.
This paper considers the estimation problem of the dynamic passengers flow for such a system. First, a network model which represents the dynamic passengers flow is proposed. Then, it is shown that by the model a dynamic flow can be treated as a static flow without any approximation. Finally, a method for solutions is proposed with an assumption that each passenger chooses a route so as to minimize his travelling time and number of changes.View full abstractDownload PDF (919K) -
Hiroyuki TAMURA, Osamu NARAI1979 Volume 15 Issue 3 Pages 360-365
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper deals with a technique of tradeoff analysis in multiobjective systems. For this purpose a technique called IPSM (Interpretive Preference Structual Modeling) is proposed. It is obtained as an application of Warfield's ISM (Interpretive Structural Modeling) to our problem. In IPSM we analyze a decision-maker's preference relations among many Pareto-optimal solutions of the multiobjective systems under the interactive cooperation between the decisionmaker and the model-builder (computer), and extract the decision-maker's preference structure as a hierarchical directed-graph where the vertices of the graph correspond to the Pareto-optimal solutions and the directed edges correspond to the preference relations. To show the effectiveness of the approach in this paper a numerical example of consumption-pollution problem is included.View full abstractDownload PDF (803K) -
Oichi ATODA1979 Volume 15 Issue 3 Pages 366-372
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAn optical technique is introduced for pseudo-color representation of height or deformation of a solid object, a flow velocity distribution of fluid and so on. First, a photograph is taken in which parts of movement, height, etc. are coded into their own center frequency of spatial bandpass processes. For example, a photograph of a flow of fluid carrying aluminium powder on its surface is taken under periodical illumination of a flashing stroboscope. Then the frequency-coded transparency is converted into a colored image by an optical spatial filtering processor being illuminated by spatially coherent white light and having an off-axis slit as the spatial filter.
A simple mathematical procedure is derived for estimating an output color of the processor from the spatial power spectral density of the input transparency. In the derivation the tristimulus values are expressed respectively by the output powers of the three linear systems whose power transfer functions are easily calculated under the given slit configuration. It is shown that the small-signal resolution of the processor is approximately equal to that of an incoherently illuminated optical system of the same configuration and size having an on-axis slit of the same width. It is recommended that the slit width is approximately 1/5 of the slit offset from the optical axis for optimally compromising the excitation purity with the resolution, and that the bandwidth vs. center frequency ratio should be less than 1/5 to make chromaticity determined mostly by the center frequency and little affected by the spectral shape of input signals.
Experimental results are shown in colored figures. The rangeability of input frequency is roughly 1:1.5, but it can be adjusted using a prism if necessary.View full abstractDownload PDF (3186K) -
Teruo MIYASHITA, Chikara SATO1979 Volume 15 Issue 3 Pages 373-376
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new kind of oscilloscope is proposed and realized. The oscilloscope named the graphic oscilloscope is capable of displaying graphic patterns whose shapes and positions can be changed by analog inputs.
This system generates, by its analog circuits, more than ten kinds of basic characters such as a circle, a triangle, a line vector and so on. More complex patterns are synthesized by combining the basic characters under the control of a microprocessor.
Two application examples, a two-channel analog CRT meter and a face pattern display are illustrated. They give us satisfactory results showing the basic functions of the graphic oscilloscope.View full abstractDownload PDF (1670K) -
Manabu NISHIKAWA, Bunjiro ICHIJYO1979 Volume 15 Issue 3 Pages 377-382
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSThis paper describes a differential-gap varying method for measuring the dielectric constants and thicknesses of thin films.
In this method, an electrode assembly of two high tension circular plate electrodes is used. The electrodes are arranged symmetically parallel to a grounded plate electrode that is jointly moved by a micrometer head.
Many of the errors of the conventional method are eliminated in the method used here.
It is also shown that this method serves as an experimental tool for simultaneous determination of the permitivity and the thickness of a film theoretically as thick as even 0.1μm (1000Å) with a high degree of accuracy.
In our experiments, the data for the thickness and dielectric constant of a polyester film are found to be consistent and in reasonable agreement.View full abstractDownload PDF (1722K) -
Yasuo TACHIBANA1979 Volume 15 Issue 3 Pages 383-388
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSAlmost all industrial plants have nonlinear properties. Therefore, when an output of the system is controlled to be constant, the equiliblium point is varied by the mean value of the unregulatable inputs (disturbances) and the system parameters. If the changes of the equiliblium points can be detected, they are useful information for setting of controllers to the linearlized system at the equilibrium point or for detecting the abnormalities of the system. In actual plants PID controllers are widely used for feedback controls and for feedforward controls to feedback controls. The reason for this is due to the ease of their parameter setting even in the case that the equilibrium points vary between some bounds. The adaptability of PID is principally depending on the effect of I-element used in a feedback controller.
In this paper one detection method of equilibrium changes is presented. This is based on the observation of the output value of an I-element in a PID controller used for set point control. For the two cases, one with known statistical properties of the disturbances and the other with real time observation of them, the properties of the proposed method are discussed. For the numerical example, some results obtained from the simulation of a rolling process of a steal mill are presented.View full abstractDownload PDF (748K) -
Nobuharu AOSHIMA, Yasuhiko MIYAGAWA1979 Volume 15 Issue 3 Pages 389-394
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSA new method of generating signals whose amplitude distributions are Gaussian and whose power spectra can be given arbitrarily is proposed. Gaussian distributed random numbers generated by adding uniformly distributed random numbers are placed in an inverse Fourier transform region where each number is considered to represent a frequency component of a random time signal. By varying random numbers, the inverse Fourier transform is repeated. By specifying the variance of the random numbers as a function of frequency, the power spectra of the time function can be given arbitrarily.
The Gaussian signal whose spectrum is limited in a certain band and whose autocorrelation function is triangle is considered as an example. When the ensemble averages are considered, their amplitude distributions are Gaussian, but in considering finite time length sample functions, their band widths cannot be made too narrow, because a sufficiently large number of independent sample points should be taken from one sample function.
The inverse Fourier transform is carried out by FFT algorithm in a computer and the obtained values are converted to analog signals by a D-A converter. To obtain smooth analog signals, an interporation method based on the sampling theorem equation is developed.
To generate long time signals, an interrupt method is used, where signal output and computation are performed in parallel. In this method the frequency of obtained signal is limited to a maximum by computation time. Up to 500Hz signals could be generated by the authors' experiments. A generating method of higher frequency signals is also devised.
Gaussian signals whose spectra are band-limited and whose autocorrelation functions are triangular shape are generated by a minicomputer. Their amplitude distributions, power spectra and autocorrelation functions are measured and they are shown to have sufficiency good qualities.View full abstractDownload PDF (938K) -
Hiroyuki TAMURA, Yutaka NAKAMURA1979 Volume 15 Issue 3 Pages 395-401
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSIn this paper, we introduce a new concept of convex dependence in two-attribute space Y×Z as an extended concept of the utility independence, where we consider the change of shapes of conditional utility functions. The concept of the convex dependence forms the basis of a wide range of trade-off analysis and generates various decompositions of a utility function u(y, z), which include Keeney's additive/multiplicative decomposition and Fishburn's bilateral decomposition as special cases.View full abstractDownload PDF (783K) -
Zenta IWAI, Yoshihiro KUBO1979 Volume 15 Issue 3 Pages 402-403
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (231K) -
Kageo AKIZUKI, Fumio TADA1979 Volume 15 Issue 3 Pages 404-405
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (245K) -
Seiichiro HANGAI, Shoji IWASAKI, Shun-ichi OMORI1979 Volume 15 Issue 3 Pages 406-407
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
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Shunshiro OONISHI, Konosuke AKITA1979 Volume 15 Issue 3 Pages 408-409
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
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Haruhiko ASADA, Hideo HANAFUSA1979 Volume 15 Issue 3 Pages 410-411
Published: June 30, 1979
Released on J-STAGE: March 27, 2009
JOURNAL FREE ACCESSDownload PDF (264K)
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