This paper describes the “micromachining” of quartz wafers by anisotropic etching of alpha-quartz. No previous systematic studies of the anisotropic etching of alpha-quartz have been reported, although such technology has been used to fabricate miniature quartz tuning fork resonators for wrist watches. Such micromachining technology differs from conventional planar integrated circuit processes in that its purpose is to produce three-dimensional devices.
The purpose of this investigation was to predict cross-sectional shapes of micromechanical devices made of quartz wafers using photolithography and anisotropic etching. The etching rates of quartz wafers with 21 different angles of cut were measured, and were interpolated using spline function in order to determine etching rate of all quartz crystal surface. As a result, the cross-sectional shapes of devices fabricated on wafers with any angle of cut could be predicted by applying Jaccodine's method.

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A method is proposed for estimating a geometrical distortion of an imaging system. This method estimates the geometrical distortion from the change of the image intensity caused by a slight shift of the distortion. This method is based on our experience that when we wave a piece of glass, e.g., a fisheye lens, before an object, we can perceive the optical distortion of the transparent body by the motion of the object pattern. In this paper, we analyze the effect on the image intensity by the shifts of the object and the imaging distortion. An equation concerning the differential coefficients of the distortion, those of image, and image changes by the shifts is derived by Taylor expansion of the image intensity at each point. Then, least-square methods are introduced for the estimation of the differential coefficients of the distortion. Experimental results are presented which demonstrate the proposed method works well for a simulated random dot image. Another experiment using a real scanning electron microscope image which was distorted intentionally by a magnetic disturbance also showed the effectiveness of the method.

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Water vapor pressure of a saturated salt solution is inherently constant at a given temperature and utilized for calibration of hygrometers as a humidity fixed point. In this paper, the humidity fixed points were realized respectively in a glass desiccator and in a box with an air stirrer and examined experimentally.
The state of saturated solution and the change of ambient temperature are important and effective for realizing the humidity fixed point. It is suitable for a rapid attainment of humidity equilibrium that the saturated solution is in a state of slushy mixture with water and salt. Although the equilibrium relative humidity of the saturated solution does not change much with temperature, a transient change of the relative humidity is observed following a sudden change of ambient temperature. The transient change amounted to -1.5%RH/°C at the maximum.
The equilibrium relative humidities by respective saturated solutions of magnesium chloride, sodium bromide, sodium chloride and potassium chloride were accurately measured in a glass desiccator with use of a humidity sensor calibrated against the humidity standard of the National Research Laboratory of Metrology. The humidity values measured agree with those of the salt-humidity table in the literature and accordingly the reliability of the table was confirmed. The humidity fixed point by saturated salt solutions can be realized in a desiccator with the precision of 1%RH, if temperature is well controlled.
To improve utility for practical use, the humidity characteristics of the fixed point realized in a cubic box were also studied under various conditions, such as stirring in the box and changing surface area of saturated solutions. It becomes clear that the stirring is important for uniform distribution and for quick attainment of equilibrium of the humidity, and the time required for the humidity equilibration is decreased to about 30min under stirring condition.

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Slug-dye experiments were conducted to study the tidal exchange of the Seto Inland Sea with the largest hydraulic model in a horizontal scale 1/2000. To analyze the velocity at the margine of the dye cloud, image processing techniques have been developed. The techniques include the extraction of the boundary of the dye cloud and the flow direction through tuft images.

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A new synthesis method for digital multi-input multi-output partial state feedback control system with preview feedforward compensation is proposed. The preview feedforward compensation is discussed from two different points of view. (1) a preview feedforward compensation which minimizes a same performance index as that for the optimal feedback control system, (2) another preview feedforward compensation which minimizes a different performance index from that for the optimal feedback control system in order to improve the transient response. The performance index value is analytically derived when applying these preview feedforward compensations. In simulation and experimental studies, it is shown that the performance index value considerably decreases and the smooth transient response of the control system is attained by making used of the former preview feedforward compensation. It is also shown that the transient response is fairly improved by making use of the latter preview feedforward compensation. When some of the state variables are not directly detectable, the full state feedback control system with these feedforward compensations is transformed into the partial state feedback control system by using the straightforward method without designing an observer.

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The present paper gives high resolution spectral line estimation algorithms which involve optimized prefiltering of the observed signals consisting of sinusoids and white noise, before applying the linear phase prediction method. Two types of the prefilter are investigated for resolution enhancement: in the first one the coefficients are determined so as to minimize a specific criterion, and in the other one the center frequency and the bandwidth of the bandpass filter are decided to minimize an alternative criterion. It is clarified that the two kinds of prefiltering can improve significantly the resolution in the estimation of closely spaced frequencies and can reduce the biases in the estimates even if we utilize a low-order prediction model. The prefilters can be determined automatically in a data-adaptive way in accordance with the data number, signal-to-noise ratio and signal frequencies.

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This paper reports on the experimental clarification of a method of reducing the interacion effect between the input and output proper to the Dynamically Tuned Dry Gyro (TDG) through improvements of the Rebalance Control Circuit (RCC) and the use of subtorquers with the main torquers.
First, the hardware of each element of the RCC, which is necessary for noninteracting control, was designed and manufactured, based on the parameters and figures specifying the TDG used in this study. Then, transfer functions of the TDG were derived, taking into consideration the manufacturing accuracy of the element, and the element was examined analytically to see how relationships between inputs and outputs, and the reduction of interaction effect, were affected by its accuracy. Next, the frequency characteristics of direct and cross transfer functions were measured experimentally by applying electrical inputs to the TDG, and their characteristics were transformed to values eqivalent to those for applied mechanical inputs. It has become evident after these experiments that the gain in cross transfer function, which corresponds to the degree of reduction of the interaction effect, can be decreased remarkably without influencing the characteristics of the direct transfer function which characterizes the system performance of the TDG used in various missions. Finally, it is concluded from the analysis and experiment described above that a fundamental concept of design and manufacture of the hardware of a noninteracting control system necessary for the development of future TDG's with excellent performance has been established.

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The light weight design of robotic manipulators, office automation instruments and so forth is demanded for high speed operation and excellent energy efficiency. Then, step motors are widely used as digital actuators of position control system.
In this paper, the dynamic characteristics of the flexible arm postion control system drived by a single phase excited step motor are investigated theoretically and experimentally. In the analysis, first, the Lagrangian of the coupling system of a step motor and a flexible arm is obtained by use of the finite element method in consideration of the flexural vibrations of the arm. Then, the matrix equation of motion of the coupling system to arbitrary pulse is derived by applying the variational theorem and the Hamilton's principle to the Lagrangian, and the matrix equation is solved exactly by the Laplace transformation method and the residue theorem. Furhtermore, the continuous step response is obtained by use of the continuous conditions of the system at the moment when each pulse is applied to the step motor. The experimental results about the single step response and the continuous step one agree well with the numerical results, and the validity of the present analysis is confirmed.

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This paper describes a versatile multi-window vision system, which is developed for providing robots with flexible and multiple visual attention capability. Chapter 1 is introduction. A window is a local region to be processed for one attention. The multi window vision system provides a large number of windows. The location, shape, size, and resolution of each window can be controlled by a special LSI, independently and simultaneously. In Chapter 2, we describes the concept and architecture of the multi window vision system. The multi window vision system is designed to build a pandemonium model by means of multi microprocessors. In order to avoid the image access bottleneck in parallel processing, we introduced a transmiter-receiver into the multi window vision system. Chapter 3 describes the transmitter unit which broadcasts input images to the window receivers. In Chapter 4, the details of the logic circuits inside the window control LSI is described. The LSI chip controls window parameters which are location, size, shape, spatial sampling rate, window memory access, and the display of the window image. In Chapter 5, the image processing unit that implements the LSI chips is described. Chapter 6 shows the experimental results using the image processing unit. Chapter 7 is Concluding Remarks.

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A self-organizing fuzzy controller is able to use linguistic decision rules of control strategy and has a strong adaptive property by virture of its rule learning function. While a simple linguistic description of the learning algorithm first introduced by Procyk, et al. has much flexibility for applications to a wide range of different processes, its detailed formulation, in particular with control stability and learning process convergence, is not clear.
In this paper, we describe the formulation of an analytical basis for a self-organizing fuzzy controller by using a method of model reference adaptive control systems (MRACS) for which stability in the adaptive loop is theoretically proven. A detailed formulation is described regarding performance evaluation and rule modification in the rule learning process of the controller. Furthermore, an improved learning algorithm using adaptive rule is proposed. An adaptive rule gives a modification coefficient for a rule change estimating the effect of disturbance occurrence in performance evaluation. The effect of introducing an adaptive rule to improve the learning convergency is described by using a simple iterative formulation.
Simulation tests are presented for an application of the proposed self-organizing fuzzy controller to the pressure control system in a Boiling Water Reactor (BWR) plant. Results with the tests confirm the improved learning algorithm has strong convergent properties, even in a very disturbed environment.

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The GMDH (Group Method of Data Handling) is well-known technique for obtaining a mathematical model of complex phenomenon. The fuzzy GMDH has been reformulated by the possibility measure. In the fuzzy GMDH algorithm, possibilistic linear systems with fuzzy parameters are used to obtain a possibilistic linear model by using a multilayer procedure, given the observed data.
Water temperature in dam reserviors exerts influence on water supply, irrigation and so on. Accordingly, the prediction of water temperature is needed to avoid bad influences. In this paper, the fuzzy GMDH is applied to prediction of water temperatures. The data of air temperatures and water temperatures in the Daiichi Yahagi Dam are observed during from July 1st to July 31th, 1980. By the fuzzy GMDH algorithm, the model of water temperatures is built from these data. The estimated model is used to forecast water temperatures from August 1st to August 31th, 1980. As a result, 71% of all observed data are included in the estimated fuzzy outputs. Therefore good estimated intervals are obtained. The fuzzy GMDH can be used as interval analysis. A vague phenomenon must be forcasted by intervals which represent our ignorance.

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This paper is concerned with differential sensitivity analysis for optimal values of differentiable convex programming problems whose objective and constraint functions include parameters.
It is well known that the directional derivative of optimal-value function of convex programming problem can be represented as a min-max type positively homogeneous function with respect to the direction. Based on this fact, we investigate the relation between the generalized gradient and the local convexity or concavity (the Clarke regularity) of optimal-value function. The main results obtained here are (i) characterization of a subset of the generalized gradient of optimal-value function, (ii) relation between the Clarke regularity and the generalized gradients of optimal-value functions, and (iii) sufficient conditions for the optimal-value function to be locally approximated by convex or concave function (the Clarke regularity).

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The problem to find the initial markings which enable the specified firing counts of transitions ina Petri net is of particular importance in both practical and theoretical points of view. In practice, it corresponds to find initial resources necessary for realizing given occurrences of events. In theory, it constitutes alternative approach to the reachability problem when the specified firing counts are the nonnegative integer solution of the matrix equation of the reachability problems.
The notion of the Token Flow Graph (TFG) is introduced in this paper to analyze and solve the problem. TFG is obtained by expanding the original Petri net according to the firing count of each transition. It indicates the paths of possible token flow when the specified firing counts are realized. TFG and its extended form give the sufficient condition to bo satisfied by the initial markings which enable the specified firing counts, and, consequently, provide the way to find the enabling initial markings and the partial order of transition firings as well.

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This paper describes the shape representation of 3-D objects which utilizes the normal vector obtained from 2-D images.
It is proposed to use the 2-D plane which is obtained by projecting the Gaussian sphere perspectively as the characteristic space for representing 3-D objects, and the shape of the surface of any 3-D object is corresponding to the figure on this plane. As for some basic curved surfaces, the characteristic figures on the plane are shown and these are extracted in the characteristic space. Each of them is easily extracted using techniques for image processing. The method for the detection of ellipses in the characteristic space is described in detail. And, it is experimentaly clarified that the detection of two or more ellipses in the same characteristic space is possible. Since the extraction of the 2-D figure is carried out all over the plane, overall region analysis without an effect of the positional error becomes possible.
Moreover, the technique, by which the curvature of the curved surface is presumed by using the ratio of the area of the curved surface in the scene and the density of the normal vector in this characteristic space, is obtained. The method, by which both principal curvature and the tangential line vector are used, is proposed for representing the object which can not be satisfactorily represented only in the distribution of the normal vector. It is also shown that the characteristic space proposed earlier is also applicable to the method, because the change of the vector is shown as the figure in this characteristic space.

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The fine-wire microelectrode technique for recording activity of single neurons has been used more than two decades. We have developed a new microdrive which is more compact and mechanically stable than previous versions, and still requires only hand tools for construction.

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This paper proposes a design method of a discrete-time model reference adaptive control system for periodically time-varying plants. The idea is based on the discrete-time Fourier transform theory that a periodic signal with period NT, where T is a sampling time, has only N distinct values of angular frequency.

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This paper is concerned with the problem of designing observers for linear multivariable descriptor systems. A simple procedure is presented for constructing a low order observer of linear descriptor systems.

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