Recently, the advancement of micro-computer and communication technologies makes it possible to construct a distributed control system. The distribution of the control system aims at not only fault-tolerance but also online maintenance and expansion. It is proposed for these objectives to give autonomy such that each controller can control its responsible control region even if some other controllers and their sensors fail or even before they are constructed. This property of the system is defined as autonomous controllability.
Necessary and sufficient conditions for autonomous controllability of a linear system with perfect information and with imperfect information are derived. Moreover, the difference between autonomous controllability and conventional controllability, which does not assume the failures and expansion of some controllers and their sensors, is clarified.
The problems to design a system satisfying autonomous controllability are how to divide the system, to make a simple and expandable structure and to allocate the control region to each controller. These problems are respectively resolved by weakly coupling condition among subsystems, uniform structure of each subsystem and state re-transformation method.
These discussions make it partially clear to relate control, reliability and expandability.

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The eqsilon method which is proposed by A. V. Balaklishnan is convenient for solving numerically optimal control problems. However, since this method approximates the problems by functionals which are to be optimized, even the possible analytic solutions contain error (called theoretical error).
In this paper, the theoretical error bound is proved to be propotional to a value ε in the epsilon method. Moreover, since in general numerical solutions are given instead of analytic solutions, there arises numerical error, so the theorem is also shown which gives the total of theoretical and numerical error.

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In this paper, properties of dynamic behaviors in nonlinear systems exhibiting chaos are investigated under small random perturbations.
The principal line of attack is to find the stationary distribution of the randomly perturbed systems and to evaluate the dependence on the initial state by expanding the deterministic sensitivity concept to the stochastic version.
Illustrative examples are discussed, including the comparative aspect between the deterministic sensitivity and the stochastic one.

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The algorithm of multiplier method is discussed from the view point of dual problem for nonlinear programming problem. We point out that if a sufficiently large penalty parameter is chosen, the updating algorithm of Lagrange multiplier will be similar to Newton's method for solving dual problem.
For the purpose of applying effectively this feature of updating algorithm and avoiding difficulty to minimize the multiplier function for a large penalty parameter, we propose a multiplier method employing information on condition number of Hessian matrix for its multiplier function. It is expected that the multiplier method employing information on condition number becomes a practical algorithm for nonlinear programming problems with many inequality constraints, because there is no need of memory space to store the information for Hessian inverse of dual objective function.

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In this paper, a variant of the basis factorization methods is developed for solving a multi-stage linear programming, in which the output of one stage is an input to the next stage. The method is devised to use the special staircase structure of the original basis. In this method, a set ofelementary column operations transforms the original basis into a staircase matrix which significantly reduces computational efforts for matrix inversion.
It is shown that the original basis can be obtained by a pivot among the several columns. Based on this fact, a new algorithm is proposed where the relative cost factor of the original non-basis is easily obtained by memorizing the column vectors corresponding to the variables which are included in the original basis but not in the working ones.
The algorithm has been coded by FORTRAN and applied to an in-plant energy control system. The results prove that the method is practical and superior to a conventional simplex method (MPS-II) in terms of computational time and storage.

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In urban economics housing has been treated as nondurable goods so far. If housing is nondurable, the spatial structure models of housing market are static and at long-run equilibrium and are concerned mainly with allocation of housing in a city. However, to consider dynamical models, housing must be thought of as durabl geoods, and in this case it is important to take account of maintenance, which compensates deterioration of housing quality.
In this paper, the behavior of housing suppliers to maintain housing is formulated as one of optimal control problems. Housing is characterized by its quality, and suppliers' profit is maximized with respect to maintenance investment. Some properties of their behavior are derived: The behavior is classified into six types, and if they cease to maintain housing, they will never do that again. Furthermore, the effects of the changes of housing structural characteristics on the maintenance are also considered.

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The ballistic galvanometer and the fluxmeter have been conventionally used for the precision measurement of magnetic flux, which are limited to 0.5∼1% accuracy due to the drift of DC components, the effect of the low input impedance and so on.
The fluxmeters are usually calibrated by either of two methods: one is the use of a standard magnetic field and a search coil, or another is the use of a mutual inductor and a constant DC current source. These methods are time consuming because of the complicated arrangements, operation and calculation.
To solve these problems, the author devised a fluxmeter calibrator (FC) on trial introducing a new concept. The FC consists of a crystal oscillator, a binary U/D counter, a programmable ROM and a DA converter, and generates the single sweep sine wave voltage which is shifted by its peak value. Main performances of the FC are as follows:
(a) Calibration range for magnetic flux: 10^-5∼10Wb
(b) Setting figures and resolution: 4 figures, 10^-9Wb
(c) Calibration accuracy: ±0.05% of range
In addition, the FC provides ability to self-calibrate by the output DC voltage or the manual input clock and calibrate within 2 seconds for each test point.

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A new method of measuring instantaneous flowrate of unsteady laminar flow in a circular tube is developed.
The dynamic behavior of the unsteady flow has been investigated experimentally and analytically by the authors, as shown in the previous papers. It was confirmed by the experiment that the transfer function between the centerline velocity and the flowrate was valid to express the dynamics.
The inverse Laplace tranform of the transfer function gives a weighting function and then the flowrate in the time domain is obtained by the convolution of the weighting function and the centerline velocity, which is measured by a laser Doppler velocimeter in the case of the developed system. The calculation of the convolution is done by a microcomputer system and the wave form of the result, that is the flowrate, can be displayed on a CRT in real time.
It was verified by the experiment that this developed system was useful to measure the unsteady flowrate.

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It is well known that the reflection characteristics of object with rough surface in optical sense like the paddy field vary with the view angle, the solar angle and their growth level. This is the reason why it is difficult to exactly analyze the agricultural data obtained by the space-borne and the air-borne sensor MSS. It will be very convenient and helpful for observing some ground truth or correcting the MSS data if there is such a simple model as can simulate accurately and easily the reflection characteristics of object with rough surface.
In this paper, we describe a new and powerful reflection model for object with rough surface like the paddy field. This model is named “Equivalent Reflectance Model”.
This model can permit us good and reasonable explanation of the view angle characteristics temporal ones and things like that the ground truth or MSS data contain in themselves.
It can also give us the precise equivalent reflectance of the paddy field on any conditions.

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In recent years, over one million loudspeakers are manufactured a month for TV sets, radio sets, etc.. The purpose of the loudspeaker is to produce high-fidelity sound. As abnormal sound is not permissible, all of them must be inspected at the end of production line. It is painful for human inspectors to listen to the fullpower sound.
In this paper, a method to inspect the loudspeaker by acoustic signal processing techniques. The spectral map shows that it is not necessary to sweep the frequency of the driving signal but sufficient to fix it to the free air resonance frequency (f₀). In this system, f₀ is measured by a loudspeaker tester and a sine wave of frequency f₀ is generated by a micro-computer and a DA converter. Every loudspeaker is driven by this sinusoidal wave of its full power. Its sound, acquired synchronously to the driving frequency, is emphasized with a high frequency band-pass filter and digitized into 12 bits. Its power spectral distribution, obtained by Fast Fourier Transform through an array processor, is inspected by a linear classification method. In the classification process, we use the distance from the average power spectrum of normal loudspeakers. The number of abnormal loudspeakers tested is 38, which has been extracted during two days in a production line.
The result showed that the learning rate was 100% and the recognition rate was 89.5%. Misrecognized sounds were so critical that some human inspectors gave an undecisive classification. The automatic loudspeaker inspection method provides a better environment for human inspectors and is effective to quality control of the products.

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A simple analytical model of a fluidic pump with two diodes is made and the relation between the pumping efficiency and some system parameters is mainly discussed. Its validity is examined expermentally with a pumping system constructed by Zobel-type diodes (chamber diameter: 6cm, height: 1cm) and a pumping cylinder (diameter: 15cm), under some delivery heads (1-2.2m, 9.9m).
The results obtained are as follows:
(1) When the mean liquid level in the pumping cylinder, h, is set at the middle point between the critical suction and delivery levels, the pumping efficiency η has a maximum value (about 0.2 in this equipment).
(2) η is little affected by the amplitude of liquid level variation in the pumping cylinder, when the amplitude is not too small.
(3) An optimum delivery pressure, p⁺₀, exist for a delivery head or a mean delivery flow rate.
(4) As the suction pressure is equivalent to h, the vacuum source equipment could be saved by the decrement of h and the increment of p⁺₀.

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This paper concerns with a new moving part fluid-logic device based on a pneumatic amplifier with a positive feedback system.
A nozzle is built in an enclosed chamber and counter-faces the movable closed end of a set of bellows placed in the chamber. Air is fed from a constant pressure source into the enclosed chamber through the nozzle and flows out to the atmosphere through a vent orifice provided on the chamber wall. The orifice, the nozzle and the closed end form a pneumatic amplifier circuit with positive feedback caused by the bellows action and the circuit is so arranged to have bi-stable transfer characteristics. Pulsating pressure is introduced in the bellows and the pressure in the enclosed chamber maintains either a high pressure level nearly equal to the supply pressure or a low pressure level equal to the atmospheric pressure. By adjusting the gap between the nozzle and the closed end of the bellows initially, the device can be employed as an inverter with Schmitt-trigger and a bi-stable flip-flop.

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In this paper, singularity problem of articulated robot arms is discussed. The existence of singular points is an inherent problem in controlling articulated robot arms. The conventional motion resolution method using inverse matrices is not applicable at singular points. To make matters worse, in the neighbourhood of singular points, the closer a robot arm approaches singular points, the more the movement of joint angles is required for a given movement of the robot hand. It causes large errors in the motion of the robot hand because of the saturation of driving torques of joints.
Singularity low-sensitive motion resolving matrix is defined, which improves the motion of robot arms in the neighbourhood of singular points. This motion resolution method is applicable to all types of articulated robot arms whether redundant type or non-redundant type.

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