Riding comfort of a train on curved track is generally evaluated with an index on stationary lateral acceleration of vehicle body. However, it does not consider the influence of running vibration throughout the curve and also it can not be applied on transition curve. This paper suggests a new method that quantifies riding comfort on whole curved section including transition curves. Experiments with subject passengers are carried out using a simulator to estimate the correlation between the riding comfort and combinations of related three parameters on vehicle body, the conditions of which are made based on lateral accelerations measured on a vehicle body. The parameters are as follows : riding quality level calculated from the running vibration, stationary lateral acceleration due to a centrifugal force and lateral jerk on a transition curve. As a result, the following matters are clarified. (1) Riding comfort on whole curved section including transition curves can be quantified by the index combined with above mentioned three parameters. (2) The influence of each parameter on riding comfort is estimated quantitatively. (3) The deterioration of riding comfort due to the increase of stationary lateral acceleration caused by speed-up can be compensated by decreasing the vibration level of vehicle body.

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Power-assist system technology and its applications to manufacturing systems have attracted special interest recently. For example, automobile assembly processes utilizing power-assist systems have existed. Many power-assist systems for industrial uses possess simple power-assisting function only. Conveyance of controlled objects is generally processed by another system. Then, one of the authors has studied on the positioning method of a cart with motor by means of a smooth switching from the servo access control for the conveyance function to the impedance control for the power-assisting function. The nonstationary optimal control method and the nonstationary impedance control law are applied to obtain the smooth switching. However, this method requires a force sensor for detecting the operator's force. To improve the usefulness and safety of the system, a force sensorless control method for the system is studied in this paper. Instead of the force signal, this study utilizes the acceleration signal of the cart. The method shows its effectiveness by experiments.

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This paper describes the equivalent mechanical and electrical models for systems of the vibration suppression in flexible structures using piezoelectric elements. There are two main methods to suppress vibration of flexible structures. One is active vibration control and the other is passive vibration suppression. Because they include both mechanical and electrical systems, the mechanism of the vibration suppression is complicated and can not be understood easily. To make matters worse, the knowledge of the mechanical vibration suppression device and the electrical circuit are not utilized in those systems with piezoelectric elements. Hence, this paper describes the way to derive the equivalent mechanical and electrical models. Using those equivalent models, the mechanism of the vibration suppression can be easily comprehended and the knowledge of mechanical and electrical systems can be applied effectively.

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This paper proposes new methods which improve the robustness and the performance of the passive vibration suppression by a dual electrical absorber using piezoelectric elements and analog circuits. Two types of methods which use two inductances were proposed in this paper. Because the electrical systems of new methods have two resonance frequencies, those new methods could improve the performance and the robustness by choosing the inductances and resistances of the circuit. Optimum values of the circuit were derived for both cases with and without the variation of the stiffness of the main system. The effectiveness of new methods and the optimum values of the circuit were verified by calculation and experiment.

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Environmental concerns have increased demand for induction motors with low noise characteristics. Electromagnetic noise has been a particularly concern. Relation of electromagnetic noise and natural frequencies has been studied for more than twenty years. However, a new phenomenon has arisen, in which motor noise changes with increase in motor temperature. In this study, the relation-ship between electromagnetic noise and temperature was analyzed quantitatively. It was found the relation of electromagnetic noise and temperature as follows. In temperature 20-70°C, noise level does not varies, but in temperature 70-140°C noise level decreases drastically by 6 dB (A) at first and then increases by 3 dB (A). Natural frequencies of 273 Hz and 350 Hz appear at 20°C, and two natural frequencies unite at 70-140°C in the experiments. A two-degrees of freedom system with core and coil end considering temperature effects was used for calculation of the natural frequency. These calculated values agreed with experimental results. The relation between variation of the natural frequency and temperature in electromagnetic noise was analyzed and the cause of noise variation with temperature was clarified.

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This paper deals with cluster feeding mechanism using loop type resonator's train. The resonator consists of loop and leg part, respectively. Each part was actuated by bimorph type piezoelectric members. The deflection of loop part and the bending of leg part generated by piezoelectric bimorphs makes an elliptic motion at the center point of the upper member. If resonators are put in a train and are actuated at the same frequency, it can feed objects on the upper surface of its train. The trial feeder, we developed, consists of 8 resonators (4 resonator pair). It could generate elliptic motion in arbitrary phase and could feed thin or soft objects that could not be fed with usual feeders. The feeding speed, that is obtained by dividing the feeding distance at the feeding time with camera vision, changed by phase shift of the input to leg part (z) with the input to loop part (y). The principle of feeding with the cluster feeder was clarified, and it was shown that the theoretical feeding speed fairly agree with the experimental ones. The cluster feeder can feed a thin or a soft object without damaging.

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This paper deals with the legless chair with seat motion which follows standing up action from a floor for an elderly with dysfuctions of lower extremities in their home. The trial model realized its motion with the mechanism, which has been devised and acquired the patent. The chair consists of the paired four-link mechanism linked by both end fixed wire and actuator placed under the elbow rest in order to obtain uplift stroke of the seat. Pseudo two degree of freedom movement pulled ahead with forward tilting of the upper body has been effectively realized by the link mechanism with the only one actuator in principle. The largest advantage of the mechanism has the seat motion which can be easily adapted only by position adjustment of the sliding pulley without difficult adjustment of wire length for individual specificity and secular change of the old people. Characteristics of quasi-static motion and mechanics were analytically clarified with the link model for human and mechanism. Movement of the mechanism and standing up action of the human body was obtained by analysis of image captured with CCD camera. The experimental values agree approximately with the theoretical results.

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We developed an instrument to aid transfer for aged person with leg fault. The instrument has a very simple structure to turn on the single fulcrum circumference and is able to reduce the load to care. For rational design, we analyze loads with a simple analytical model which is composed for rigid body link model for the instrument and human body, and linear spring model for the elasticity of bottom and seat cushion. The results of theoretical analysis explained lift up motion of the transfer. The maximum requirement moment was decreased monotonously with the decrease in an installation angle of a breastplate board. To minimize the maximum requirement moment, we should minimize the angle of tilting forward. It was possible to reduce the requirement force for lift up under 1/3 of the elder's weight by the use of the instrument.

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This paper describes a new numerical method to calculate efficiently the effect of a multilayered structure which is located on the coupling surface between structure and acoustic cavity. This method utilizes the transfer matrix built from analytical wave function sets for each layer. Solutions for Helmholtz equations derived from Biot's theory are applied for the layer of absorbing porous material such as polymer foams. Transfer matrix for multilayered structure is then applied to form boundary conditions between structure and acoustic cavity and the modified equations of motions for the coupled systems are obtained. The new calculation method employed transfer matrix for multilayered structure is finally validated by a numerical example which resulted into the reduction of calculation time by the factor up to 40 without the severe loss of accuracy comparing results by the standard finite element analysis.

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In this study, in order to improve effectiveness of the abnormal signal detection, the technique of constituting an Average Real signal Mother Wavelet (A-RMW) from two or more real signals has been proposed and its effectiveness has been confirmed. The main results obtained can be summarized as follows : (1) For constructing A-RMW by two or more signals, the Symmetric Complex Real signal Mother Wavelet (SCRMW) first was constructed respectively and then the average SCRMW was obtained by adding them. Finally the average SCRMW obtained above was normalized and the A-RMW was obtained. (2) The proposed constructing method of the SCRMW is different from the traditional Complex Real signal Mother Wavelet that the phase information of all the frequency components has been cut off and symmetric property can be obtained. (3) The proposal method is applied to the rattle noise source detection of a car, and its effectiveness is examined.

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Acoustically induced random vibration of satellite equipment panels is a critical design consideration in satellite development. The prediction of this random vibration is required in the early stage of satellite design in order to specify the random vibration environments of satellite equipment. Various prediction methods for the response prediction using Statistical Energy Analysis (SEA) have been developed, namely : (i) Lewis method, (ii) Point mass impedance method and (iii) Area coupling impedance method. However, first method has limited accuracy for a heavy and concentrated equipment, second one often overestimates, and third one requires a detailed parameter. In this paper, a new method combining the asymptotic apparent mass of specific equipment with Lewis method is proposed. This method takes the elastic behavior of satellite equipment instead of rigid mass into consideration. The acoustic excitation experiments for nine real satellites (404 equipment total) are conducted to compare the exiting methods with the new method in statistical sense. The result from the comparison shows that the new method provides most accurate prediction in important frequency range.

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A Magnetic Bearing Wheel (MBW) with inclined magnetic poles is under development. This paper deals with fine tuning of the magnetic bearing controller. In general, it is very difficult to identify disturbance factors of the magnetic bearing, and no model-based controller can achieve sufficiently low disturbance condition. In this paper, it is shown that all disturbance factors can be accurately identified using displacement sensor output and electromagnet current in the low disturbance condition realized by the disturbance feedback controller in our 3rd report. In addition, if the results of disturbance factors are applied to the magnetic bearing controller, only the magnetic bearing controller can greatly decrease disturbance of MBW without additional disturbance sensors.

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This study deals with seismic isolation design in industrial facilities. Design spectrum modified for long period structure is suggested. Response spectrum calculated by linear analysis using actual seismic waves is different from response spectrum of seismic design for the range of long period. In addition, friction isolator is expected to absorb seismic energy. This effect should be utilized positively in seismic design. However, seismic isolation effect depends on the friction characteristic of system. Therefore, adjustment of frictional force becomes very important. This paper shows Friction Response Spectrum for long period by the synthetic seismic wave using design spectrum. The Friction Response Spectrum is able to obtain the optimum frictional force of seismic isolation instead of non-linear analysis and estimate response magnification of long period system with friction. Moreover, equivalent damping ratio is estimated from Friction Response Spectrum for long period system. Equivalent damping ratio can easily calculate response of friction system.

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This paper proposes new methods to find a transformation matrix used in predicting the dynamic characteristics of large space antennas in component mode synthesis. Current methods such as the Guyan reduction use mass and stiffness submatrices to calculate the transformation matrix. In the proposed methods, the transformation matrix is derived from both the internal and boundary modes. The effectiveness of the methods is verified by applying them to a cantilever beam and a truss structure. Numerical results show that the prediction accuracy of the dynamic characteristics depends on the number of modes used in finding the transformation matrix. Accurate prediction is possible when the number of used modes does not exceed the boundary degrees of freedom considered in the same kind of modes such as out of bending modes or torsion modes.

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To enhance transport safety and reliability of ropeway systems, it is essential to reduce the swing of the carriers by wind. As for swing damping equipment for the ropeway system, passive equipment which does not need a power supply can be realized easily for the system. In this passive equipment, it plays an important role to give damping force to additional mass in order to reduce the resonance amplitude of the ropeway system with this equipment. This paper proposes two-ball rolling type damping equipment in which damping force to additional mass is generated self and makes clear an adjustment method of parameters of this equipment. The effects of this equipment that we confirmed by simulation and experiments are reported as well.

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We had clearly shown in our previous research paper that semi-active seismic isolation systems with the controllable friction damper using the piezoelectric actuators, reduce response accelerations and displacements, when compared with the results of the passive systems. However it is difficult to apply this controllable friction damper to large structures, because super large piezoelectric actuators and large amplifiers are needed to drive the friction mechanism. For this reason, a new controllable friction damper using a hydraulic pump driven by giant magnetostrictive actuators was developed to solve this problem in this particular study. This hydraulic pump can make quick responses, when driven by the giant magnetostrictive actuators. It is also possible to make the hydraulic system easily enhance the capacity of the friction damper. Characterization experiments of the new controllable friction damper and excitation tests of the semi-active seismic isolation system with this new controllable friction damper were conducted. The results of these tests confirmed the effectiveness of this semi-active seismic isolation system with the new controllable friction damper.

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The previous paper reported on the practical model of φ40 pneumatic nutation motor. This time, we developed a new type pneumatic nutation motor of φ10 diameter, named the OFW-D type pneumatic nutation motor consisting of a diaphragm which has some pneumatic rooms, the OFW type bevel gears (a nutant bevel gear, a fixed bevel gear and a bevel gear pair of equal teeth number). Furthermore, a new type pneumatic nutation motor realized torque up without changing dimensions of a diameter direction using a principle of a lever is developed (named the OFW-DL type pneumatic nutation motor). In this report, first, the driving principle and design of these motors are presented. Next, the prototype of these motors are fabricated and tested. This paper concludes that the mechanism is suitable for realizing small and high-torque nutation motors.

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In this paper, an iterative PID controller design method with unfalsified control theorem and extended L2 gain criterion is considered. The design method utilizes fictitious reference signal which is derived from plant input-output data for candidate controller falsification. The proposed design method includes a procedure for adjustments of the performance specification which leads to the improvement of the convergence property. The effectiveness of the proposed method is evaluated by experiments on a magnetic levitation system.

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Piezoresistive materials are those whose electrical resistivity changes in response to changes in mechanical strain. Piezoresistive sensors, usually consisting of a piezoresistive device working in concert with a flexible structure, are widely used in a variety of sensors such as pressure sensors and accelerometers. This paper describes a newly developed topology optimization method for the design of the flexible structures used in piezoresistive sensors. First, the design specifications for obtaining sufficient output voltage in a Wheatstone bridge connected with a piezoresistive device, and the structural stiffness requirements are clarified, and the objective functions satisfying the required specifications are formulated. A multi-objective optimization problem is also formulated for use in finding an optimal structure that incorporates all the design specifications. An optimization algorithm is constructed based on the SIMP (Solid Isotropic Material with Penalization) method and SLP (Sequential Linear Programming). Finally, several examples are presented in order to confirm the usefulness of the proposed method for the design of piezoresistive sensors.

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In this paper, we have discussed on the effect of the knowledge sharing for the multiple robot system which is equipped with the advanced telecommunication systems. These days, the broad bandwidth telecommunication method has been brought into the world of robotics. This has enabled the mobile robots to have advanced communication tools. This is not only for master's or administrator's command but for the exchange of the knowledge obtained through the operation. This knowledge sharing system will realize the evolution of the knowledge level of the entire module group and help the equalization of the intelligence level. Therefore, we propose the utilization of the knowledge sharing robot system at manufacturing scenes, and demonstrate the effectiveness by the balancing procedure. Utilizing this knowledge sharing system, we have recognized the system's effective performance in autonomous and cooperative behavior at production line, and consequently, the feasibility of the cost reduction and improvement of the efficiency.

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We describe a new robotic assist device : a passive assist arm (pas-arm). Pas-arms are intended for direct physical interaction with a human operator, handling a shared payload. Pas-arms are physically passive. Their purpose is not to enhance human strength, but to provide virtual guiding surfaces, which constrain and guide the motion of the payload within a shared workspace. Pas-arms have three joints and a three dimensional workspace, but possesses only a two degrees of freedom, due to the reduction of degrees of freedom created by a combination of continuously variable transmissions (CVTs) and differential gears. The combination of CVTs and differential gears places one mechanical constraint on three angular velocities of the joints. Pas-arms have no joint actuators and no force sensors. Thus they are potentially well suited to safety and low cost. This paper proposes a basic concept of pas-arms and explains a principle and a construction of pas-arms. We discuss the relation of pas-arms to conventionally actuated robots and another type of assist arms. We also describe range of transmission ratio of CVTs.

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In endoscopic sinus surgery, the diseased part is so narrow that it's difficult to staff assistants around. So, surgeon has to hold the endoscope with his one hand and manipulate surgical tool by the other hand. Therefore, he cannot perform an operation satisfactorily so that endoscopic support mechanism is needed. We took in Mechanical Gravity Canceller : holds a posture without actuators to endoscopic support mechanism. And we developed high accuracy positioning endoscopic support mechanism with adjustability of the mechanical impedance characteristics. As evaluation experiment, we used realistic sinus head dummy and had otologist perform an operation to this head dummy with endoscopic support mechanism to compare to one-handed surgery. As a result, the force given to head dummy was reduced. Thus we can say this endoscopic support mechanism is effective for endoscopic sinus surgery.

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This paper concerns the modeling and control of a pneumatic artificial muscle applied to robotic manipulators. It is important to structure the static model by using the principle of virtual works considering the dissipated energy which consists of the frictional loss and the elastic loss in the modeling of a pneumatic artificial muscle. A special attention is directed to the modeling of an antagnostic drive unit as the actuator for robotic manipulators. A new design method is proposed for the manipulator control system incorporated with an antagnostic drive unit by introducing its inverse model derived. The basis of the present design method is a sophisticated application of the compensation method for two-stage control by linearization and servo compensation. Feasibility of the proposed method has been examined both through simulation and the 2-DOF control experiment using a 2-link horizontal manipulator. It has resulted in success to indicate the promising aspect of the proposed design method for control system using a pneumatic artificial muscle.

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Previously we reported a method for displaying the shape of an object by using an array of whisker sensors. The array of whiskers was pressed against the object to be measured and the deflection of each whisker was measured. The measurements were used as inputs to a neural network to recognize the shapes. However, the previous method needed a larger number of whiskers to recognize the wider surface, because the array of whiskers has to be in full contact with the entire surface. Therefore, this study presents a new method in which a much smaller number of whiskers are dragged across the surface of the measured object to distinguish the shapes. The method is performed in the following manner. Firstly, a smaller number of whiskers are dragged across an object and each whisker deflection direction is distinguished at discrete time intervals. Next, the neural network continuously monitors the output from the whiskers and produces a result that characterizes the surface at the current scan position. Lastly, by building up a map of the classification of the entire surface, the geometry of the measured object can be displayed. This study exhibits the hardware and software required for displaying shapes, and shows examples of the results obtained from the measurements of some objects.

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Recent years have brought hope that driving support systems tailored to the characteristics of each driver can be developed. To accomplish this, a driver model must be constructed that considers the driver's psychological function when inferring driver behavior. This paper thus proposes a method to infer driver behavior by capturing time-series steering angle data at the time of lane change. The proposed method uses a static type conditional Gaussian model on Bayesian Networks. By using this method, if the driver behavior of the subject and learned data nearness of features (norms) are below a certain level, it is possible to infer driver behavior with nearly 100% probability. Moreover, compared to the HMM models, this method reduces the rate of incorrect inference inclusion.

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The decrease of wheel load variation is effective in enhancing stability, safety of high-speed train. In this paper, we conduct the simulation analysis on wheel load variation in order to figure out the mechanism of wheel load variation in consideration of track irregularity such as sine wave and to investigate the influence of the relation between unsprung mass and static wheel load. As a result, we figured out as follows : The wheel load variation at high speed increases according as the wheel speed because the vertical inertia force of wheel increases widely by high-speed running along the flexible rail with irregularity. If sleeper passing frequency and the irregularity passing frequency is close to the primary natural frequency of the wheel/rail system, the wheel load variation becomes larger. The decrease of wheel mass is very effective in decreasing the wheel load variation in comparison with the decrease of static wheel load.

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This study presents details of the project that would estimate joint angles of human from captured images by using model matching method. While human subjects perform on a trampoline, the researcher converts the movement into information with a human inertia model. Performance is photographed by four high speed cameras. The posture of human subjects was determined by using model matching method. However, three dimensional model matching method has some weak points such that search range becomes huge. Accordingly, by solving an equation of free-flying system, the joint value of the following body movement is presumed using that of the present body movement. Finally, one forward somersault with half twist at layout position was reconstructed.

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Because of change in woman's social status, the number of working women is growing and the demand of the breast pump is increasing as well. Commercial products of the, breast pump are applying only negative pressure for sucking and many users feel a pain for a long term use. Whereas a baby is using peristaltic motion as the result of tongue and jaw action in addition to suction. In this research, therefore the breast pump with a baby-like motion is developed. In order to realize baby-like peristaltic motion, a cam mechanism is applied. Also, for producing negative pressure, a crank mechanism is utilized. As the result, it turns out that the breast pump developed is realized the same peristaltic motion and suction pattern as a baby.

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There has been a remarkable increase in demand to quantitatively measure and evaluate texture especially in the process of product design for cosmetics, apparel, and household products. The purpose of this study is to analyze the relationship between texture perception of geometry and pseudo skin and effect of lubricants. Solid lubricant and fluid lubricant on pseudo skin are selected as samples. Next texture of samples is evaluated by semantic differential method and texture scores is calculated. Then, suppress strength, dynamic friction, and tracing speed of a finger are measured while an examinee evaluated the texture of samples. From these results tribological characteristic of samples are calculated. Finally the relationship between tribological characteristics and texture score are analyzed using the multiple regression analysis method. In conclusion relationship between texture and tribological characteristics are clarified. Now it is able to evaluate the difference in textures which were considered difficult to distinguish.

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Helical steel cords have been in use as an important and convenient machine element for load and displacement transmission. In various mechanical devices, such as automobiles, helical steel cords have been applied as a kind of simple and mechanical remote operation system. Although helical steel cords have been used widely, the mechanism of fatigue failure has not sufficiently been clarified due to the complicated fracture phenomenon. It is important to understand the fatigue failure mechanism for the optimum design of helical steel cords. The purpose of this study is to clarify the fatigue failure mechanism of helical steel cords. Some experiments and analysis were carried out under tension and bending combined conditions. Especially, the relation between the location of the damaged wires, the failure mode and the cycles to failure were investigated.

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The achievement of the ultra-high-speed rotation is needed for performance improvement of the turbo machinery. The ultra-high-speed rotors, supported by herringbone grooved aerodynamic journal bearings, have a good advantage in miniaturization of these machineries. The objective of this work is to study herringbone grooved aerodynamic journal bearings for support and ultra-high-speed rotor. This paper described about the effects of the grooves, the bearing clearance, the groove depth and bearing-support-methods of the herringbone grooved aerodynamic journal bearings in the ultra-high-speed rotational regions. Two types of bearing test device, rigidly support type and O-ring support type, were developed. The experimental works were conducted by elevating the supply pressure and the flow rate gradually with monitoring the behavior of the rotor in vertical type test devices. As the results of this works, a 6.0 mm diameter and 30.75 mm length rotor has been operated at a rotational speed greater than 509 000 rpm by using the herringbone grooved aerodynamic journal bearing which has the groove depth of 4 gm and is supported by two O-rings.

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In the design and analysis of engine bearings for automobiles, the elastic deformation of bearing surface due to high pressure and temperature of oil film affects significantly on the bearing characteristics. Thermo-elasto-hydrodynamic lubrication analysis (TEHL) is usually used to consider such effects, but a large amount of calculation time is needed to obtain the numerical solution of oil film temperature by solving the conventional type of 3-dimensional energy equation in TEHL. This paper describes a rapid method of numerical calculation of oil film temperature in engine bearings. In this modeling, it is assumed that the temperature distribution in the oil film thickness direction takes the parabolic form. Under such and assumption, averaging the 3-dimensional energy equation over the film thickness, the 2-dimensional energy equation is newly obtained. The numerical solutions of oil film temperature based on the 2-dimensional model are compared with the solutions based on the 3-dimensional model. It is confirmed that the calculation time is remarkably reduced to obtain the oil film temperature with an allowable accuracy. Moreover, the predicted oil film temperature by the 2-dimentional model is compared with measured data, and the good agreement is seen between them.

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Aerodynamic journal bearings have been successfully applied to high speed laser scanner motors. In these devices, herringbone grooved aerodynamic bearings have been usually used due to their high stiffness and excellent stability at high speeds. However, there is a disadvantage that it is slightly difficult to make herringbone grooves on the shaft surface, which raises the manufacturing cost. In this paper, a newly designed aerodynamic journal bearing with diagonal grooves is proposed which is much easier to make than the conventional herringbone bearings. The static and dynamic characteristics of the proposed bearing are investigated theoretically and experimentally.

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We have developed a method utilizing low-coherence phase-shifting interferometry (LCPSI) to directly visualize molecularly thin lubricant films coated on diamond-like carbon (DLC) surfaces. In contrast to conventional point-by-point scanning methods, this method straightforwardly measures lubricant distributions in three dimensions using phase-shifted two-dimensional interferograms which are generated by a Michelson interferometer and a robust feedback controlled phase-shifting system. To effectively suppress the image noise caused by unwanted interference, we employed a low-coherence light source rather than a laser. Moreover, an image subtraction method, in which the pseudo lubricant thickness attributed to surface roughness and system noise is first measured on a non-lubricated disk and is then subtracted from the result obtained on the lubricated disk, was introduced to eliminate the influence of surface roughness and system noise. By measuring nanometer-thick perfluoropolyether films coated on DLC surfaces, we demonstrated that the LCPSI is capable of providing real-time three-dimensional measurements with a thickness resolution of sub-nanometer and a spatial resolution of several micrometers.

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The printing method of the dye sublimation printer is to push and heat a dye-based ribbon by a thermal print head, and transfer the dyes to desired positions on a printing paper. From the view point of energy saving the load as low as possible is desired for the dye sublimation printer because the lower normal load reduces total friction in the printer. However, the image quality printed on the printing paper became worse when the applied load was reduced. Thus an estimation method of determining the optimum load must be established. In this paper the dyes on the ribbon were assumed to be transferred and diffused to the paper at real contact area. Thus real contact area of three different types of papers against an optical prism was measured with a contact microscope. As a result, the correlations between the optical density and the real contact area were experimentally obtained. The optimum loads for the thermal print head were predicted from a viewpoint of real contact area.

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Supercritical water (SCW) is obtained at pressures above 22.1 MPa and temperatures above 648 K and is advantageous because of its great solubility in organic liquids. Waste treatment of toxic substances, such as the decomposition of polychlorinated biphenyle (PCBs) and their application to the recycling of plastics using SCW is very effective and has less negative influence on environmental destruction. However, SWC was found to corrode a reactive container remarkably, and as a result, the shortened longevity of the container obstructed its industrial use. Moreover, a large-scale reactive container is necessary for the recycling of waste plastics and resources. Therefore, the use of an expensive Ni based alloy in the container is difficult from an economical standpoint. Application of austenitic stainless steel, comparatively economical in Ni based alloy, is has been tried for the container material, but provides insufficient corrosion resistance under the conditions of SCW. In this study, improvement of the corrosion resistance by the nitride process of SUS316L alloy under the supercritical state is considered. (1) Under the influence of a nitrided process, SUS316L alloy endures during usage as a container material in the vicinity of 640K due to the decrease in the corrosion rate by transpassive corrosion. (2) There is a correlation between the corrosion speed and the permittivity for the nitrided SUS316L alloy. Thus, the longevity of a reactive container correlates to a value of the permittivity of solution. (3) Above the value of 25 permittivity, it is unsuitable for use as a reactive container because of the flaking off of the nitride layer of the SUS316L alloy surface.

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Near-dry machining attracts increasing attentions for environmental and economical benefits. However, it has not been fully utilized in industry because of its premature stage of development and this situation has largely resulted from the lack of fundamental understanding of the tribological action regarding its lubrication media. In order to take a full advantage of near-dry machining, therefore, this study investigated basically the lubrication mechanism using orthogonal cutting in controlled atmospheres and carried out practical drilling with MQL system which is the most representative and successful near-dry operation. As a result, it was found that oxygen and ester adsorbed onto the nascent clean surface created by cutting, and the ester presented a high lubrication effect. Although adsorption of oxygen provided a preferable influence on cutting steel, it caused low performance when cutting aluminum alloy. In practical drilling, further, oxygen demonstrated a favorable influence on cutting steel and the presence of oxygen failed in drilling aluminum alloy.

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The objective of the present research is to develop systematic methods for planning and analysis of the geometric tolerances of the three-dimensional machine products. The tolerance zones of the geometric features have been investigated, in the previous paper, based on the definitions of the geometric tolerances, and the parameters have been defined to describe the statistical deviations of the geometric features within the tolerance zones. Mathematical methods are discussed, in the present paper, to estimate the statistical deviations of the positions and the orientations of the geometric features, based on the deviation parameters and the relationships between the datum features and the target features. In particular, emphasis is given to the analysis of the statistical deviations of the geometric features under the MMC (maximum material conditions), which specifies the interaction between the dimensional tolerances and the geometric tolerances. The proposed method is applied to the analysis of the deviations of the geometric features, to which both the dimensional tolerances and the geometric tolerances are required.

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Design parameters of industrial products are usually decided by testing some prototypes. The reduction of the number of prototyping and experiments leads to the short lead-time and low cost. Design Navigation Method (DNM) has been proposed to optimize the parameters that have complex relations to multiple evaluation items. DNM is built on the experimental design method and the information integration method, which evaluates multiple evaluation items with a unified criterion as the amount of information. However, DNM has not considered interaction effects among design parameters. In this paper, the problem in case that interaction effects are significant is discussed, and a modified-DNM is proposed as an analysis method in such case. As a case study, the modified-DNM is applied to a design problem of an electric circuit. Through the case study, it is confirmed that modified-DNM calculates optimized design parameters holding balance of multiple evaluation items although interaction effects are significant.

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