The disk test on the disk-machine was carried out in order to determine the strength of slide-rolling contact under condition of specific sliding Σ₁=5.35 and the sliding velocity was changed in the range of Vg=0∼20 m/s. The surface treatmeants for our tests were case-hardening, tufftride treatment, boronizing, hard chrome-coating, and ceramic coating. These were combined together. The materials were mainly SCM415 and further chilled cast iron (FC30) according to JIS. Limiting load for scoring, specific wear, and coefficient of friction were investigated under above mentioned condition. The lubricating oil for this investigation was turbine oil. The limiting load for scoring and the specific wear were changed very widely according to the kind of surface treatment and material, but the value of coefficient of friction lies in a certain range and does not change so widely according to the above mentioned various conditons.

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This paper describes the static and dynamic characteristics and the application of silicone gel. The dynamic characteristics are experimentally investigated to 200 Hz. The static relation between the draw ratios and the stress is expressed by the three-dimensional relation of the ideal rubber. The dynamic stiffness increase and the viscous damping coefficient decrease with an increase in the frequency. Their values increase as the draw ratios are decreased. The gel is applied to the spring-mass system and the beam system. As a result, the applications of the gel restrain the resonance gain of the system that doesn't have the gel. The restraining effect increases with a decrease in the draw ratios. Results of the analysis show that the damper of the gel restrains the gain of their systems and is superior to the rubber.

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The three-dimensional dynamic response of an internally damped hollow truncated cone translationally or rotationally driven at the base is determined by the Ritz method. With the displacements of the hollow truncated cone assumed in the forms of algebraic polynomials, the dynamic energies of the body are evaluated on the basis of the three-dimensional theory of elasticity, and the equations of motion of the body are determined from the Lagrange equations. By the application of the method, the dynamic response curves are calculated numerically for the hollow truncated cones driven by a sinusoidally varying axial or transverse deflection, or angular rotation at the clamped base, together with the natural frequencies and the mode shapes, and the results are presented in some figures.

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A methodology of the shift synthesis of real eigenvalue problems is presented so that the structure modification can be synthesized for a given set of the change of eigenvalue and eigenvector. The change of the aimed eigenpair due to the design parameters is estimated by the first order perturbation of the finite element solution in the vicinity of the baseline structure. The approximate equation between the objective eigenpair and the estimated one is employed as a subsidiary condition for the functional comprised of the sum of the squared design parameters. The design parameters are determined by the minimization of the functional so that the modification is sought as near the beseline structure as possible. The numerical examples are carried out in regard to the modification of a cantilever beam and a simplified truck chasis by use of the bending stiffness of the beams as design parameters.

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This paper presents a dynamic identification method which is based on ARMA (Autoregressive/ Moving-Average) model fitting. The method has the advantage that only observed random time history is required for the dynamic characteristics identification without calculating transfer function. The method has the following two procedures. First, in order to estimate ARMA parameters from observed time history, an order-update recursive (LWR) algorithm is introduced. Second, modal parameters are calculated by use of ARMA parameters. As a fundamental example, a five degrees of freedom system is identified with the aid of numerical simulation. From the results, it is shown that estimated modal parameters agree well with the exact value, even without as much data as was required in the former method.

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It is a well-known phenomenon that unstable rotor vibration occurs when rotors, partially filled with liquid, are rotated through a certain range of rotational speeds. This type of self-excited vibration appears in large-scale continuous flow ultracentrifuges, due to heavier liquid forming laminations with greater weight density. The unstable vibration results from a forward whirl rotor motion. An electromagnetic bearing control, reacting to detection of the rotor displacement, can produce particular damping force characteristics as are required for stabilization. Our control technique features an additional cross coupling network between x and y directional channels. This is equivalent to the damping effect generated by the cross stiffness of the bearing reaction : Kxy and Kyx. The sign of the cross stiffness especially depends upon the whirl direction. This optional control strategy using the cross effect is successfuly experienced by combating unstable flow induced forward rotor vibration.

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This paper investigates the dynamical characteristics of a forced nonlinear vibrating system with a retarded argument. The entrained subharmonic oscillations of order l/2 of this system have been analysed, using the averaging scheme. It has become clear that quasi periodic vibrations and unbounded oscillations besides the subharmonic vibrations can occur over the frequency region, where the entrained subharmonic vibrations of the order of l/2 will appear, depending upon initial conditions. Then, as the retarded argument varies, we will be interested in the variety and structure of the boundaries which separate basins of attraction, making use of cell-to-cell mapping and the Poincar6 mapping method.

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As is often pointed out, the in-plane vibration in a wedge or a sector plate is one of the most important problems in elastodynamics not to have been solved exactly so far. This problem may be related to the dynamic stress concentration and the scattering of elastic waves by cracks, notches and inclusions. This paper presents an exact series solution for the problem. The series satisfies the governing equations and the boundary conditions given at the two edges of a sector plate term by term. It is shown by use of the solution that the stress singularity at the vertex is the same to that of the corresponding problem in elastostatics.

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The parametrically excited oscillations in a rotating shaft system where a periodic axial force is applied are studied theoretically. The treated model is a four-degree-of-freedom system where a disc is mounted on an elastic shaft with a circular cross section. We investigate the followings : the forms of parametric excitation terms in the equations of motion, the kinds of parametrically excited oscillations which occur in this system, the influences of the shaft rotating speed on the width of the unstable regions, and so on. The differences from other kinds of parametrically excited systems, such as an unsymmetrical shaft system, an unsymmetrical rotor system, and a column system with a periodic axial force, are also clarified.

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An approach is proposed for estimating natural frequency and mode shape of an orthotropic plate which has attached spring-mass systems. The approach consists of three steps : 1) reduction of the governing equation of the plate with attached spring-mass systems to that of a plate with concentrated masses which vary with the vibrating frequency ; 2) application of the Receptance method to the reduced governing equation in order to obtain the solution for the governing equation by using the solution of a simple orthotropic plate with neither spring nor mass ; and 3) estimation of the natural frequency of the plate with attached spring-mass systems by substituting the above solution into the iterative formula proposed previously by the author. This approach can be applicable to an orthotropic plate with an arbitrary shape and boundary condition. As numerical examples, the approach is applied to three kinds of clamped orthotropic rectangular plates ; 1) with a spring support, 2) with a concentrated mass, or 3) with a spring-mass system. Thus natural frequency and mode shape are obtained for some flexural rigidities and aspect ratios.

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In the present paper, the frictional vibrations in a mechanical system are studied theoretically using an average method when the friction-velocity characteristic curves are given by several types of function. The steady-state vibrations, or limit cycles, obtained from the average method are compared with the corresponding approximate motions regarded as the positively exact solutions, which are obtained from the piecewise linear system with the friction-velocity characteristic curves approximated by a polygon having numerous segments. Moreover, the effectiveness of the use of the average method in the theoretical analysis of frictional vibrations is shown in three types of friction-velocity functions when the nonlinearities in the system are not too large. Lastly, an easily revisable method is offered in which almost exact solutions can be obtained by modifying the solved curves estimated from the average method.

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This paper describes an investigation into influence of the lengths of the slits and the number of those on squeal. In a disk with four slits at regular intervals there are two 2-0 modes which have two nodal diameters. One has a node in the center of a slit (sine mode), and the other has a node between two adjacent slits (cosine mode). The difference Δf₁ between the natural frequency of the sine mode and that of the cosine mode becomes greater as the slits grow longer. On the other hand, there is only one natural frequency of the 3-0 mode in the disk. Our squeal theory predicts that the second mode squal is reduced as theΔf₁ of 2-0 modes grows greater. Experimental results show that the second mode squeal disappears and the third one is generated when the slits are long. In conclusion, four slits are effective on the second mode squeal, but not on the third one. And also the n-th mode squeal is not generated when theΔf₁ of n-0 modes is large.

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The object of this paper is to study a method for passing through the critical speeds of rotating shaft systems, and in particular, to search optimal turning points and returning points for minimizing the maximum flexural amplitude by changing the driving acceleration after initial start-up. This method is based on the following idea : A large acceleration is available during transition through critical speeds because the maximum amplitudes of flexural deflection are reduced ; however it is unsuitable except for the region of critical speed because the torsional deflection increases. In order to realize the optimal operating curve, a linear optimal tracking system is applied. This control system consists of optimal state feedback and a compensation input. It has been proved that this control system reduces a transient torsional vibration due to a sudden torque change and a torsional resonance vibration when the shaft passes its resonance region.

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When a low temperature fluid flows into the bottom of a tank filled with a high temperature fluid, thermal stratification occurs because of differences in density. After a scram of a fast breeder reactor, the outlet temperature of the reactor coolant falls quickly, and a thermal interface appears in the hot plenum. Oscillation of the interface was observed in thermal-hydraulic tests with water as a simulant coolant. The characteristics of the oscillation were examined, and an analytical model was proposed which explained the mechanism of the oscillation growth. The low density fluid was entrained by the high density fluid flow and was sucked down periodically. The buoyant force of the sucked fluid supplied energy to the oscillation. The analytical results for the range of oscillation growth agreed well with the experiment.

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In the field measurements of pressure pulsations in the reciprocating compressor and piping system, the high frequency components are often measured. They have very high frequency compared with the frequency range of pressure pulsations which cause engineering troubles such as piping vibration. This report investigates the mechanism of the generation of the measured high frequency components. As a result, it is suggested that : (1) those components are generated by the quarter wave resonance in the drains or the vents used as a nozzle for the measurement and are found only in the nozzle, and (2) the installation of an orifice at the inlet of the nozzle is effective to eliminate the high frequency components due to the quarter wave resonance, but there is a possibility that the orifice will change the characteristics of the low frequency components in the nozzle.

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In the previous papers, a new active vibration control method, that is, a pole-zero active vibration control method, was proposed. It is the purpose of this paper to realize the vibrationless forge system with the pole-zero active control and to verify the capability of the proposed method. First, this paper investigates the control effect of the pole control method constructed by a feedback control. Then, adding the zero control method in terms of a feedforward control to the system, the pole-zero active control method is realized, and its effectiveness for the suppression of impact vibration is demonstrated. Next, with a view to clarifying the robustness of the control system, experimental conditions such as material of test piece, dropping stroke of hammer head, impact numbers are varied. In addition, by changing the natural frequency of an anvil support system, the characteristics of the control system are discussed.

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For manufacturing equipment of VLSI chips, etc., it is desirable to have isolation floors which are effective not only for strong earthquakes, but also for weak earthquakes and even ambient micro-vibration. A three-dimensional isolation floor was developed to satisfy such requirements. For horizontal isolation, each column of the floor was supported by a newly developed multi-stage rubber bearing which provided the floor with a horizontal stiffness corresponding to a natural frequency of 0.4∼0.5 Hz, and could undergo a horizontal displacement of 20 cm. For vertical isolation, the floor was equipped with inner frames suspended from beams of the floor by coil springs, on wich the equipment was mounted. The inner frames, loaded with the equipment, had a vertical natural frequency of 0.9 Hz. Seismic excitation tests and micro-vibration tests were carried out for a large-scale model of the floor having dimensions of 4×4×1.8^Hm and a weight of 9 550 kg. The tests showed that the floor performed very satisfactorily for various vibrations whose amplitudes ranged from 10^-3 to 10⁰ m/s² in acceleration, and from 10^-7 to l0^-1 m in displacement.

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In the case of the earthquake isolation of entire buildings, the performance of isolation for the internal equipment depends on damping characteristics. Three types of isolation systems using lead shear dampers, viscous shear dampers and their combinations of an equivalent capacity were examined to find the most suitable ones for the equipment in industrial facilities. In this study, the dampers generating the same deflexion of rubber bearings to an earthquake input were regarded to have the equivalent capacity. Mathematical analyses were carried out to investigate the performance of the isolation systems, which depended on the main properties of the system (the first natural frequency of the isolated building and the capacity of the dampers) and the input conditions (peak acceleration and dominant frequency of earthquake excitation). The results showed that the viscous shear dampers could not only attenuate the response accelerations of the internal equipment in all ranges of frequency, but also limit the excessive deflexion of rubber bearings more effectively than any other dampers. Consequently, the viscous shear dampers were considered to have the most desirable properties for the earthquake isolation systems suitable for buildings of industrial facilities.

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Three kinds of modeling methods in substructure testing were considered : free mode synthesis, constraint mode synthesis, and free mode synthesis with mass loading. When substructures are modeled using the principal modes, the system eigenmodes are expressed by superposition of these original modes. For this reason, in case that the substructures are modeled in free junction boundary conditions, definite constraint conditions occur in the system mode shapes in terms of some differential coefficients. This constraint increases the truncation error and makes the conversion worse. It is shown that the mass loading technique relieves this constraint, and has almost the same effect on reducing error as that of constraint mode modeling.

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Position controls of pneumatic cylinders are considered to be very difficult, because of nonlinearities in the system such as friction in the ram and ramchamber compliance. A pneumatic cylinder system consisting of an electro-pneumatic servovalve and a doubleacting ram is studied experimentally to develop an effective use of the system for the follow-up control on position. A velocity control loop is added to compensate for the position response. Parameters of the control law are designed such that the damping coefficient of the dominant pole of the control system is 0.707 (the optimum damping coefficient). A learning strategy which was proposed by one of the authors in the previous paper is applied to the present system. Effects of the velocity control loop on the convergence of the learning and the control error are examined. The validity of the design of the control law is confirmed.

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A method to design a servomechanism by applying sliding-mode control to a nonlinear multivariable system is proposed. The derived servomechanism is completely decoupled during sliding motion, so that a set of servomechanisms with single input-single output is obtained. The input-output relations are given by transfer functions of which the poles are arbitrarily assigned. The system types of the servomechanisms can also be determined arbitrarily. The advantageous properties of sliding mode control to parameter variations and disturbances hold in this servomechanism. An example is given in order to illustrate the design procedure.

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An extended Howze-Pearson compensator avoiding pole-zero cancellations in a block decoupling system is considered. The basic relation that the compensator satisfies in order to realize block decoupling and arbitrary pole assignment is investigated. A design method to obtain the compensator is derived according to the basic relation. The dynamical order of the compensator is explicitly given by using the coprime fraction description of the system transfer matrix. The results are extended to the case for which partial pole-zero cancellations are allowed.

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This paper describes how to increase the stiffness of a servomechanism in a direct-drive NC hobbing machine. Since the equivalent inertia moment of the work-table is very small in the direct-drive NC hobbing machine, the rotating vibration caused by load torque fluctuation becomes very large. To solve this problem, the authors tried to apply damping torque to the servomechanism by an inertial damper. This increased the stiffness without any resonance over a wide frequency range of exciting force. The effect of this inertial damper is verified by theoretical analysis and experiments. Some gear cutting experiments proved that this easy method is practically enough to decrease the rotating vibration of the work-table in the cutting process.

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Instability phenomenon in feedback positioning mechanisms is well known in magnetic disk equipments, but it seems to the author that a comprehensive explanation of the cause of the instability have not been made. This paper presents a plain explanation of the instability encountered in a simple positioning mechanism which has one degree of vibration freedom in addition to one degree of rigid body freedom, when the negative feedback positioning force applied to one mass is provided by linear combination of the displacement and velocity of another mass. From the modal analysis of the closed system, it is found that although the increase in the negative feedback gain of the displacement increases the natural frequency of the in-phase mode, it decreases the natural frequency of the out-of-phase mode and results in instability. It is also found that the negative feedback of the velocity acts as an unstable damping for the out-of-phase mode.

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In this paper, a force control method for manipulators is presented with consideration given to object dynamics based on the adaptive control. This method for the manipulator system is an extension of the previously proposed method for gripper systems, with additional consideration given to the mass effect at the tip of the manipulator. Since present industrial robotic manipulators commonly employ the input/output position servo control system, one of the purposes of this study is to use the proposed control system to simultaneously control the position of the manipulator, the forces on the manipulator and the forces against given objects. However, it is not easy to control the manipulator, without knowledge of the objects, because the dynamics of the object inevitably comes into the overall feedback control system. Then, it is necessary to adjust the control gains, depending on handling of the objects. For this purpose, a method of the adaptive force control based on the position, and force hybrid control is presented, with consideration given to the static and dynamic characteristics of objects. Some simulations and experiments are carried out for a one-degree-of-freedom manipulator system to adjust pushing and/or holding forces to various objects, whether they be soft or hard, and they showed wider applicability and more flexible manipulation of the conventional servo controlled manipulators.

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Four-Wheel-Steering (4 WS) systeme for automobiles have been developed to improve steering response and running stability. In this paper, a new method of the 4 WS system is proposed, which is designed by the technique of a linear model following control. This 4 WS system is based on the following two concepts. 1) Front and rear wheels are steered cooperatively as the control inputs to the vehicle's motions of 2-degree-of-freedom so that the vehicle motions can be designed to have arbitrary characteristics. 2) The dynamics of the 4 WS vehicle is designed to follow a virtual vehicle model which is described in a controller. According to the theoretical analysis and numerical calculation, it is found that both steering response and running stability can be improved.

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Negotiating curves at speeds higher than normal is desired. For the purpose of improving the riding comfort, an active tilting system for railway cars is studied. This system is composed of a curve detector, curve data memories, microcomputers for making control signals, feedback circuits of swing angles, and air servo mechanisms. The whole construction of the system, the method of detecting the entrances of curved tracks, the contents of the objective control signals made by microcomputers, the criteria of the riding comfort, and the system optimization through the running tests are described.

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A pressure servo control system is necessary for the study of ventricular dynamics. Such a pressure servo system is developed here using a DC-servo motor and a digital controller. A bias signal is effective in decreasing the steady-state error in pressure control. Considering the repeatability of pressure control, we tried to implement the algorithm of calculating the bias signal automatically and met with good results.

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A new position measurement method for conduit pipelines buried under public roads is proposed. In the new method, a piece of equipment consisting of two modules, a vehicle and a probe, move inside a pipeline. The probe measures the pipeline inclination and curvature radius. The pipelines position is calculated by cumulating the inclination and the attitude obtained from the curvature radius measurement. Furthermore, position measurement accuracy is analyzed and evaluated with standard deviations of the inclination or curvature radius. The usefulness of this measurement method is confirmed through an experiment using a pipeline 80 mm in internal diameter and 40 m in length. The horizontal and vertical position measurement error is found to be smaller than 20 cm in the experiment.

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It is important to measure the characteristics of solid friction in a mechanical control system because the solid friction affects the accuracy of positioning and causes a jerking motion. Direct measuring of its characteristics requires a velocity transducer, an accelerometer, a force transducer, and so on. It is difficult to install those sensors in a control system. This paper describes the application of extended Kalman filtering to a solid friction estimation problem. This technique can estimate state variables and unknown inputs from system output. Thus, it does not need the sensors mentioned above. The effectiveness of this technique is ascertained by simulation studies.

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This paper describes a method of recognition of five vowels by machine lip reading. The feature values of height and width of lip shape and bottom position of jaw were extracted. Compared to the feature values of only lip shape, adding jaw information revealed a significant difference of discrimination. By introducing a rule based on the Mahalanobis' generalized square distance and the maximum likelihood discrimination function, rejecting the recognition of ambiguous feature values of a vowel and instructing the subject to reenter the vowel decreased the failed recognition rate. Finally, an instruction system which recognies by successively adding the reentered feature values to statistics of the maximum likelihood discrimination function was developed. Using this system, the vowels were correctly discriminated by 100 %.

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It is important to estimate precisely the sound pressure level distribution in a factory with machine tools and other sound sources. In a factory, the barrier is used as one of the means of soundproofing. In addition, the sound diffraction caused by the machine tools and tool cabinets, which act as substitutes for barriers in the factory, have a significant effect on the sound pressure level distribution. This paper deals with the simulation of the sound pressure level in a factory with barriers, which is analyzed with sound energy equations and the Monte Carlo method. Effects of diffraction caused by the barrier, working ratio, room constant, frequency, etc., on the sound pressure level are made clear.

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This paper analyzes the dynamic behavior and stresses in a gantry crane structure during traversing motion using a simulation model. Mathematical equations for the deflection curve of a crane structure are given, and the equivalent masses and spring constants are obtained through the static condensation method. The theoreticant analysis is in good agreement with the experimental results. Non-dimensional coefficients with regard to vertical and horizontal deflections and a method of describing vertical and horizontal deflections in the static state by using those coefficients will be useful in the design of gantry cranes. In addition, the result shows that the maximum stress in a structure is sensitive to the swing angle of its load, which be a significal point of discussion in the future national and international design standards for gantry-type cranes.

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The true root stresses of internal spur gears with various numbers of teeth and addendum modification coefficients are calculated by means of 2-dimensional elasticity theory and mapping function, and the position of the critical section on the compressive side of internal spur gear tooth is indicated. The stress concentration factors at the position of the critical section are calculated under various loading conditions. A practical formula for compressive true root stress of an internal spur gear tooth is derived on the basis of these calculated results. Furthermore, the root stresses calculated by this practical formula are compared with those calculated by FEM, and with measured ones, and the validity of the practical formula is confirmed.

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To investigate the mechanics of eyelet tab staking, the fastening of a lap joint with lip or petal flanges is carried out for the existence of restraint at the internal edge of an eyelet. The staking modes of the joint unions at different press fitting force are obtained, and results are discussed by use of crushing strength and slipping torque. The fastening characteristics in the eyelet tab staking, which are found to elevate crushing strength by about 5 to 8 %, and slipping torque by about 5 to l0 % were restrained at the internal edge of the eyelet.

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The effects of various kinds of factors on the fatigue strength of machined screw thread connection generally used as the fastener of machine components are examined. Effects of materials (i. e. heat-treatment), fastening force, yielding pre-tension or pre-compression before the oscillating loading test and lubrication between the connecting surfaces are chosen as the factors. Fatigue tests are performed for both types of screw thread, and bolt-nut connections made of normalized or tempered S 45 C, and obtained results are investigated in detail. Consequently, the effects on the fatigue strength are clarified. Furthermore, the strain hardening caused at each step of the machining and loading process is discussed.

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The loosening of a bolt-nut connection induced by a tangential load applied to a clamped plate is investigated theoretically and experimentally. The results obtained are as follows : 1. A driving torsional torque is induced on the bearing surface of the bolt head by slip of the bolt head on the fixed plate. 2. The above torsional torque is either in the tightening or loosening direction of the bolt according to the distribution of loads on the bearing surface of the bolt head. 3. If the resisting frictional torque on the screw thread part of the bolt in the mating nut is overcome by the above torsional torque, rotation of the bolt is caused in the nut which remains fixed on the clamped plate. The rotation of the bolt is either in the tightening or loosening direction depending on the direction of the above torsional torque. If the total sum of loosening rotation is greater than that of tightening, then the result is the loosening of the bolt. 4. The above torsional torque and the resisting frictional torque are much smaller than those expected from the coefficient of sliding friction.

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This paper relates the turbulent motion in the lubricant fluid film with centrifugal effect and the lubrication theory for thrust bearings operating in the turbulent regime. Using Prandtl's mixing length theory, three-dimensional turbulent mean velocity distributions including pressure gradients and the centrifugal effect are calculated, and the cross-coupling of the non-planar flow of the lubricant film is discussed. From these results, a turbulent lubrication equation including the centrifugal effect is derived, and pressure distributions, load carrying capacities and friction torques of a sector-inclined thrust bearing are calculated.

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This paper describes a study on the performance characteristics of sector-shaped pad thrust bearings subjected to the effects of both turbulence and fluid inertia forces. The basic lubrication equations are derived by integrating the momentum and continuity equations in the polar coordinates throughout the film thickness ; and a numerical calculation technique combining the control volume integration and the Newton-Raphson iteration method is applied to solve the equations. The static characteristics such as the film pressure, the load carrying capacity and the center of pressure are calculated for various values of extent angles and inner-to-outer radius ratios of bearing pads. The theoretical results of the load carrying capacity are compared with the experimental results. It is found that the fluid inertia forces have significant effects on the static characteristics of the bearings. Good agreement is obtained between theoretical and experimental results.

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The objective of this paper is to present the effects of the elastic deformation of a bearing sleeve on the performance of a journal bearing. A simplified model of a connecting rod big end bearing, consisting of a uniform thin shell over 270° circumference and a remaining rigid shell over 90° circumference, is investigated experimentally under static and dynamic loading, where the eccentricity exceeds unity. Under static loading the pressure distribution, the elastic deformation and the strain on the surface of the bearing sleeve are obtained experimentally and agreed well with theoretical results. Under dynamic loading, maximum eccentricity occurred when the jeurnal centre was located near the centre of the flexible shell, hence the direction of the journal eccentricity is on the opposite side of a rigid shell. Two types of pressure peaks appeared during a load cycle, one when the journal centre was located near the rigid shell, and the other when it was located near the centre of the flexible shell.

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This paper discusses the finite-width slider flying characteristics at a high bearing number Λ in a rarefied gas regime by solving the Boltzmann equation by a numerical iteration. In the infinite-width case, the load capacity difference between the slip flow solution and the present solution for the linearized Boltzmann equation was known to be very slight over Λ=100, but the present calculations for the finite-width slider show a load capacity difference of 10-20%, even at high bearing numbers, when the dimensionless load W/P₀LB is in the range of 0.2-0.5. This happens because the side leakage makes the compressibility influence and the dimensionless pressure small, compared with that in the infinite-width case.

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When stainless steel, a difficult work material, is cut, cutting forces increase and cutting temperature rises significantly. Consequently, the tool life of high-speed steel becomes markedly short. To reduce the cutting temperature, the tool is cooled internally with water, and to reduce cutting forces, high-velocity cutting oil is applied. With the method of cooling and lublication technique tool life becomes far longer, compared with that in ordinary cutting. Accordingly, this procedure would be very effective for cutting other difficult work materials.

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This paper considers a single-item, uncapacitated lot-sizing problem in MRP system, and new heuristic approaches, called Forward-Forward (FF) method and Forward-Backward (FB) method, are proposed. These methods are based on Silver-Meal (SM) method. For the initial production plan obtained by SM method, a cost minimum procedure for successive two lot-sizing periods is repeated forward from the first period or backward from the last period, which results the decrease of total cost for whole planning horizon. And to evaluate the performance of FF and FB methods, four heuristic approaches (FF, FB, SM, Part-Period-Balancing) are compared in fixed horizon and rolling horizon environments. By testing each method for various coefficiences of cost (set-up, holding) and demand variance, the cost deviation from the minimum cost by Wagner-Whitin (WW) method is analyzed. The result has showed that FF, FB methods may outperform the other heuristics and even WW method for, rolling horizon.

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The emotional state of the operator is closely related to physiological data. The authors have developed a system for physiological data acquisition to observe emotional responses among multiple operators. In due consideration of cost, resolution and invasion, cardiac pulse and the skin temperature of the face are selected as indices of the emotional state. The authors have developed a handy -sized device measuring every cardiac pulse interval, which enables us to carry out field experiments. Skin temperature is remotely measured by thermography and image processing. An experiment involving an audience in a theater has been done, applying the above-mentioned system. Results of the experiment indicate that emotional response is observed from the audience member's cardiac pulse interval and skin temperature of face.

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In human communication, an optimal speech speed for clear understanding has been studied, with special references made to learning a speech and to the individual dependency on the speech speed. The time duration of the speech, a typical pause and a specific phrase in the speech, and also a pitch period for the speech were automatically measured. In the situation where one speaks in the optimal speech speed supposed by himseif, there was no significant dependency between the voice speed and the pause duration, and there was a positive correlation between the voice speed and the pitch period. In the premature learning stage, the optimal speech speed depended on the individual, while after learning was completed, the individual optimal speed converged on the general human optimal speed. The results are useful in the development of a machine which responds to a human speaker with the speaker's optimal speed.

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An analytical method to predict the electromagnetic force in an electromagnetic forming system is presented. A spiral flat coil is approximated by coaxial circular rings carrying the discharge current from a high voltage capacitor bank. The penetration of the magnetic field of the coil into a conductive circular disk is analyzed based on the boundary-value problem for the diffusion equation. The thickness of the disk is assumed to be large compared with the skin depth. Magnetic field, eddy currents and electromagnetic force density in the disk are calculated numerically. Coil current and the magnetic field distribution in the gap between the coil and the disk agree well with the experiment, showing the validity of the analysis.

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An experiment on the free bulging of circular plates of annealed aluminum alloy by a "pancake" coil of single layer is presented in the first part. The bulging process is observed in detail by high speed photography. It is shown that the deformation begins at the annular part of the disk and the central part is bulged at the final stage of the process. A method of the simulation of the process is developed in the next part. The penetration of the magnetic field applied by the coil current into the disk is formulated by the diffusion equation to obtain impulsive electromagnetic pressure. The thickness of the disk is assumed to be large enough compared with the skin depth. An equation for the dynamic elastic-plastic deformation of a clamped disk loaded by magnetic pressure is derived. The simultaneous equations are solved numerically. The calculated bulging process agress pretty well with the experimental observation showing the validity of the simulation.

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Thermal stresses developed during the ceramic-metal solid state bonding process were analized using the finite element method. This method considers the temperature dependence of each material property and applies the elastic-plastic deformation theory for the metal. The analysis of various insert metal's properties reveals that the thermal stresses can be better accomodated with a lower Young's modulus, and that an optimum value for the insert metal's thermal expansion coefficient can be established. An approximate linear correlation is found when arranging the resultant thermal stresses as a function of the thermal expansion coefficient times Young's modulus.

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