Research on brain-machine-interfaces (BMIs) is widespread and rapidly growing in concert with the rapid advances of recent years in brain science and engineering, and systems technologies for interactions between human and machine are of major interest. It is very important for development of BMIs to analysis brain activities. In this paper, we present measurement of brain activation response for weight shifting and center of gravity movement trials using near-infrared spectroscopy (NIRS). We measured their brain activations by NIRS. To evaluate effects of skin blood flow, we used probes with two distinct distances (15mm and 30mm) for NIRS and simultaneously measured skin blood flow. We also measured the position of the center of gravity using the ground reaction meter. The results showed that oxy-Hb changes were influenced by direction of movement. We also found that NIRS signals generally reflected skin blood flow.

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In this paper, we propose a technology to automatically detect design problems of the product from user observation videos. In the proposed method, we attach color markers to necessary portions of a user and a product. Then we identify the coordinates of the markers in user observation videos by image analysis and color detection, compare the coordinates among markers qualitatively in every frame of the videos, and classify and encode user's postures in all frames of the videos. Through N-gram analysis of qualitative posture sequences in the video, we classify and encode the user's behavior patterns as specific sequences of qualitative postures. We assume that the behavior patterns which frequently appear only when the user does not understand the usage of the product should possibly indicate some design problem such as incomprehensibility or difficulty for using. By conducting some experiments to detect such behavior patterns from user observation videos, we show the effectiveness of the proposed method.

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Shuttlecock used in badminton match is light in mass, which is strongly influenced by air resistance. The highest launching velocity of the shuttlecock exceeds 300km/hr for professional badminton players. In this study, the improving performance of the badminton machine with the two rollers developed by the author is examined. Finite element models of a feather shuttlecock and the badminton machine with two rollers are made, and the projection simulations proceed with the moving behavior and contact stress of the shuttlecock. The coefficient of friction is examined from the surfaces in contact with the shuttlecock and the roller in the analysis. From the results of analysis, it is found that the roller with a large diameter attains the higher speed of the shuttlecock than the small rollers for every project. The taper angles of the roller edge and the insert height of the shuttlecock relative to the roller surface are optimized for attaining the maximum shuttle speed by the projection simulation and the response surface approach. In the results of the optimization, the performance of the machine has been improved as the shuttle speeds increased by about 7% and the stress causing the shuttle deterioration decreased. Additionally, the validity of the optimum condition has been confirmed by the corresponding shot experiments using the two-roller type badminton machine.

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Layout design of highly packed equipments is governed by not only its geometric conditions but also its physical conditions, such as thermal performance, structural strength, electromagnetic shielding. Its characteristic shares some concepts with the paradigm of multidisciplinary design optimization (MDO). However, applicability of MDO is still natively limited within continuous optimization problems. This paper proposes a basic idea for optimization-based layout design approaches, in which layout space is minimized and thermal performance is optimized simultaneously. In the approach, the three-dimensional layout topology is represented with sequence quintuple and optimized with simulated annealing (SA), while thermal performance is evaluated by thermal network method concurrently at the arranged stages in the double loop of the developed SA algorithm. The relationship between concurrency of evaluation and solution quality is discussed with numerical experiments.

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Several level set-based topology optimization methods have been recently proposed in which the boundaries of the optimal configuration are implicitly represented using the level set function. These methods naturally overcome numerical instability problems such as grayscale areas that typically appear in conventional topology optimization results. However, since most of them update design variables by solving certain partial differential equations, they lack the flexibility to deal with various constraints. This paper proposes a level set-based topology optimization method using mathematical programming, which facilitates the handling of optimization problems that have several constraint functionals. The level set function is updated using the Method of Moving Asymptotes (MMA), based on the sensitivities of the objective and constraint functionals. First, topology optimization using level set boundary expressions based on the concept of the phase field method is explained, and a new optimization algorithm for updating the level set function using mathematical programming is then developed. To confirm the validity and utility of our method, we apply it to multi-constraint optimization problems such as a minimum mean compliance problem that includes a stress constraint, and the design of compliant mechanisms including a displacement constraint.

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This paper presents a numerical analysis method for shape optimization in order to achieve stiffness maximization in thermoelastic fields. Mean compliance is used as an objective functional for the shape optimization problem. The mean compliance minimization problem on the thermoelastic fields is formulated on volume constraint condition. The shape gradient of the shape optimization problems is derived theoretically using the adjoint variable method, the Lagrange multiplier method and the formulae of the material derivative. Reshaping is accomplished using a traction method that was proposed as a solution to shape optimization problems. In addition, a new numerical procedure for the shape optimization is proposed. The validity of the proposed method is confirmed based on the results of 2D numerical analysis.

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The paper proposes a carbon taxation scheme using life cycle assessment (LCA) for clean energy vehicles (CEVs). This taxation scheme can enable to be discussed tax amount, tax revenue and total CO₂ emissions by changing the scenarios and parameters, such as: technology development, energy price and total driving distance. The authors figure out the tax rate 28.05[JPY/kg-CO₂], which makes the hybrid electric vehicle's life cycle cost (LCC) less than that of conventional gasoline vehicles. The simulation results show that LCC after taxation of electric vehicles (EVs) have lowest total cost when battery cost is 0.14 times the 2007 cost and have lower total cost than that of GVs when driven more than 221,600 km. In addition, EVs have lowest emissions when driven more than 63,000 km considered CO₂ emissions in the manufacturing phase, and it is expected that elders who drive shorter distances are best suited for hybrid electric vehicles and gasoline vehicles not electric vehicles considering LCCO₂. The proposed tax system can provide consumers with an incentive to choose vehicles with lower CO₂ emissions.

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This paper describes a nonlinear behavior of oval-type vibration in a cylindrical liquid storage tank which is high order vibration mode in the circumferential direction of the wall (axial half wave number m ≥ 1 and circumferential wave number n ≥ 2). When the vibration experiment of a cylindrical liquid storage tank was conducted by exciting its base, a nonlinear behavior of oval-type vibration occurred. At large excitation, oval-type vibration with sub-harmonics of order one-half occurred as well as that with the fundamental harmonics. Frequency analysis showed the oval-type vibration with sub-harmonics was dominant. The result demonstrated the nonlinearity of oval-type vibration. The nonlinear behavior of oval-type vibration was dynamically simulated by nonlinear explicit finite element analysis method considering fluid-structure interaction as well as large deformation. The numerical analysis results showed the same oval-type vibrations with fundamental harmonics and sub-harmonics of order one-half occurred as those in the experiment, that is, analytical vibration modes coincided with the experimental modes. It can be concluded the proposed numerical analysis method can simulate the nonlinear behavior of oval-type vibration accurately.

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Effects of base shape on natural frequency and damping of rocking of rigid body are presented. We pay attention to the fact that free vibration amplitude of rigid body decrease rapidly without dampers or damping materials. We consider rocking of rigid body is very attractive as a low cost dynamic vibration absorber. In the previous paper we propose new type rigid bodies which base shape are not flat in order to design damping characteristics of rocking of rigid body in wide range without fall. However, natural frequency of the rocking of the rigid bodies has strong amplitude dependency. In this paper, amplitude dependency of natural frequency of rocking rigid body is examined and approximate equations to calculate natural frequency and damping ratio of several types of rigid bodies are derived to discuss how to improve amplitude dependency of natural frequency. Effects of the base shape on amplitude dependency of natural frequency and damping ratio are discussed using the derived equations. From the discussion it can be seen that rigid bodies which base shape is near circular arc can improve amplitude dependency of natural frequency.

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The damping efficiency of a particle damper with hollow steel particles in a nonlinear vibrating system is investigated experimentally and analytically. The apparent of density of the hollow steel particle is almost the same as the plastics, but the melting point of the hollow steel particle higher than that of plastics. Therefore, it is expected that particle damping with hollow steel particles can perform at elevated temperatures where plastic particle damping cannot. The experimental study shows that significant damping can be achieved through used of hollow particle damping as well as plastic particle one. An analytical solution based on the discrete element method (DEM) is presented. DEM tracks the motion of granules based upon the direct numerical simulation integration of Newton's equations. Comparison between the experimental and analytical results shows that accurate estimates of the rms response of a primary system can be obtained. The height of granular materials and the clearance ratio were calculated by the gravity method. It is shown that the response of the primary system is independent of the area of the damper cavity in the case of that the mass ratio and the clearance ratio are the same.

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This paper presents sloshing suppression control of liquid with the desirable-speed transfer. In order to suppress the sloshing, mathematical model comprised of the continuous equation and the pressure equation is used and the sloshing phenomena are analyzed by using Boundary Element Method (BEM). Further, BEM model is transformed into the state-variable model. The proposed model can estimate not only first-order mode sloshing but also higher-order mode sloshing and predict the future behavior of liquid level more exactly. Moreover, the sloshing is suppressed by using Model Predictive Control method (MPC). We were able to move the container under minimum sloshing keeping the desirable speed.

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Stochastic jump phenomena in the random responses of a Duffing oscillator subjected to narrow band excitation are investigated. The stochastic jump phenomena correspond to the existence of multiple stationary responses, which differ in phase to the excitation. In our previous paper, the product of each real wavelet of response and excitation is proposed as the phase of each frequency component. But taking the moving average of the product over one period is necessary because of pulsation. In this paper, the product of the complex wavelet transform of the response and the complex conjugate of that of the excitation is used to evaluate phase of each frequency component. The central value of unstable region of the phase in the frequency response function is used as the center of the range of the principal value of the complex argument, and the value and bounds of unstable region are taken as the threshold for phase obtained from the wavelet transforms. Using this range of principal value of complex argument and thresholds, two states of the response are successfully identified, as well as the previously proposed criterion using real wavelet transform.

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In this paper, the authors have developed a new type of horizontal seismic isolation table which has large effect of vibration isolation for ordinary earthquakes and suppresses the resonance of the isolation system due to long-period seismic ground motions. The seismic isolation table is composed of a table board, X-Y rails, a baseboard, four coil springs which are attached perpendicular to the four sides of the table board and two constant-hardening type friction dampers which are attached along the X and Y rails. The trial seismic isolation table was made, and the effects of vibration suppression of the isolation table were discussed experimentally and numerically. The experimental and calculated results showed that the isolation table using four coil springs and two constant-hardening type friction dampers is effective for suppressing the vibration of an isolation table caused both by ordinary and long-period seismic ground motions.

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This paper studies the oil whip stability characteristics of a Jeffcott rotor supported in tilting-pad journal bearings theoretically. The effects of design parameters such as type of bearing seat, pad inertia, length to diameter ratio (L/D), pad number, load direction and stiffness of the shaft on the stability characteristics of the rotor-bearing system over the wide operating conditions are shown. Types of bearing seat make a great effect on the stability characteristics of the rotor-bearing system. In the case of pivotable bearing seat, the stability threshold shaft speeds increase with the preload factor under wide operating conditions. On the other hand, in the case of non-pivotable bearing seat, the stability characteristics do not change much with the increase in the preload factor. Increase in L/D ratio decreases the stability threshold shaft speed when Bearing Modulus λ is low. Pad inertia destabilizes the rotor at the high shaft speeds only when bearing modulus is low. Pad number and load direction make little effect on the stability.

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In the precision measurement and positioning fields, e.g. the semiconductor exposure machine, an air type anti-vibration apparatus is generally implemented. The above machine must continuously operate because of a high price. However, when an earthquake occurs, the exposure machine must be suspended in order to avoid mechanical contact. In detail, when seismometer's measurement is beyond the determined value, the operation of anti-vibration apparatus is stopped for safety. Although such countermeasures against earthquake are installed, there are many reports such that the exposure machines suffer heavy damage from earthquakes. To overcome the above issue, several methods to avoid the mechanical contact caused by the earthquake are proposed. Firstly, a control model of air type anti-vibration apparatus with one degree-of-freedom and two type seismic waves for simulation are shown. Next, by using the changeover concerning floor vibration feedforward and/or feedback parameters, it is shown that the relative displacement between the floor and isolated table can be suppressed while the acceleration level on the isolated table becomes large. Finally, focusing the frequency responses, especially both the transmissibility x/x₀ and (x-x₀)/x₀ in low frequency region, where x and x₀ mean the isolated table and the floor displacements respectively, the justification for both the suppression of relative displacement and the increase of acceleration level are explained.

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Energy consumption and CO₂ emission are world-wide problems. In Japan, a new project for reducing CO₂, called “Energy ITS project” has started since 2008 by NEDO (New Energy and Industrial Technology Development Organization). In this paper, a path following control method based on nonholonomic tracking control for autonomous drivinng of automotives is proposed to follow the determined path as accurately as possible. Path following control can treat the nonlinearities of the system, and it can follow the reference path more accurately. Different from tracking control, path following control separates velocity control and steering control. The performance of the designed control system which consists of a path following controller and a velocity controller is evaluated by simulation and experimental results.

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A piezoelectric linear ultrasonic microactuator with a cylindrical stator structure using electroformed Ni pipe is proposed. The length and diameter of the microactuator are about 8.2 and 2.0 mm, respectively. The stator consists of two piezoelectric ceramic (PZT) tubes connected by a 25 μm thick electroformed Ni pipe. Traveling wave propagation is generated on the electroformed Ni pipe in finite element method (FEM) simulations. The traveling wave propagation is obtained in the FEM simulation under the proper geometrical sizes, suitable boundary conditions and driving voltage signals. The trajectories of particles on the electroformed Ni pipe are elliptical motion. In the experiment, the traveling wave propagation was observed by a laser Doppler vibrometer system at the driving frequency of 701 kHz. Bi-directional motion of the slider was observed at the frequency of around 701 kHz and applied voltage V₁ of 10-40 V_p-p. At this condition, the maximum output force and maximum velocity were about 0.6 mN at V₁ = 30 V_p-p and 27.3 mm/s at V₁ = 40 V_p-p, respectively.

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To increase the applicability of ultrasonic linear motors, we have developed a holding mechanism for the transducer using parallel leaf springs. The present mechanism is compact since the parallel leaf spring structure has functions for both holding and preloading at the same time. Also, a special design for the spring characteristics provides a non-linear load-displacement region with buckling phenomena. These results in a constant preload for some range of the displacement, then the motor performance does not alter even after abrasion of contact surfaces. In this report, the relationship between the dimension of the leaf spring and the force-displacement curves was investigated in order to obtain the design appropriate for constant preloading. Moreover, the effect of the vibration reduction by the holding mechanism was investigated theoretically and experimentally. The vibration reduction was as small as less than 10 % since the stiffness in terms of the vibration direction was relatively small. Finally, the dynamic responses of the motor with the holding mechanism were measured for a sinusoidal control signal. No prominent peak was observed in the motor's responses, however, the motor velocity change was distorted near the natural frequency of the holding mechanism.

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This paper presents a controller design approach to provide the precise force control considering compensation for interference and disturbance in load devices. In the control system, a pneumatic actuator and a voice coil motor are combined as a dual-stage actuator to expand the servo bandwidth of the load control. The interference between the actuators, however, deteriorates the servo performance, especially at around the cross-over frequency. In addition, the disturbance generated by an abrasive motor deteriorates the tracking performance for the target value. In this research, therefore, a PQ method is adopted to achieve the high precision load control by expanding the servo bandwidth. Here, the compensators are designed to compensate for the interference, while a resonant filter is designed to suppress the disturbance with the specific frequency, paying attention to a vector locus of the open-loop characteristic. The proposed approach has been verified by experiments using an actual load device.

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We propose a bio-inspired visual processing system for pattern segmentation which parallelizes the information and shows high-speed performance and flexible features. Locally Excitatory Globally Inhibitory Network (LEGION) is one of the bio-inspired visual processing systems. The network is composed of an array of oscillators and Global Inhibitor. In the network, a global element had functions to receive input from the entire network and feedback. We propose a network structure in which each oscillator module shares the function and the global element can be regarded as a data field. As a result, we successfully enhance the features as a parallel and distributed system. We also propose a new oscillator model which has three modes; charge, discharge and stop. The period of oscillation is controlled by means of switching these modes and it enables the network to easily achieves both synchronization within oscillators which belong to the same object and desynchronization between different objects. We indicate the feature that the period of oscillation is proportional to the number of objects. We verify these features by simulations and experiments with real implementation of analog circuit and show the result of pattern segmentation with it.

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To determine the effects of aging on the accuracy of perceived foot position, we conducted following experiment to 10 elderly and 10 young participants. Participants were asked to adjust the position of the target line as close as possible to either most medial or most lateral parts of their foot, while they wore a modified cape that obscured their view of their feet. Once they felt that target line was appropriately placed along the foot, the distance between the line and the foot was measured. No age-related differences were identified when they were asked to place the line along with the most lateral part of their foot. Both age groups tended to place the line 10-20 mm over the foot. However, the elderly displayed smaller errors than young when they were asked to place the line along with the most medial part of their foot. We also discussed the possible reasons that explain these features in the article.

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We have been developing a robotic split-belt treadmill with different belt velocities and visual biofeedback of stance phase for the stroke patients to improve the symmetricity of their gait balance. In this treadmill system, a visual bio-feedback system of stance phase time of affected and unaffected legs is used. In this paper, a signal processing to eliminate spike and high frequency noises and oscillation of judge result of gait phase is discussed to indicate the stance phase time in real-time accurately. In addition, the effect of visual biofeedback of gait balance on their gait was analyzed in the determined biofeedback condition. Firstly, we conducted the gait experiment to determine the parameters in the signal processing such as cut-off frequency of low pass filter. In this experiment, the number of false judgment was calculated in normal gait, high cadence gait and simulated stroke gait. As a result, two parameters, cut-off frequency and the number of data to judge the gait phase, are set as 3.0 [Hz] and 10 respectively. In this condition, the gait phase of affected and unaffected legs are accurately displayed in front of stroke patient and physical therapist. Secondly, simulated stroke patients evaluated the effect of biofeedback of stance phase on the stance phase balance. As a result, the stance phase balance between affected and unaffected legs' stance phase was symmetrized by using visual biofeedback system.

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This paper proposes a novel human-friendly/cooperative work support robot. This system named PaDY (in-time Parts/tools Delivery to You robot) supports worker by delivering parts and tools to worker based on recognized worker's behavior in the car production site to reduce the worker's physical workload and improve work efficiency. The concept of PaDY, hardware of the prototype, statistic approach to recognize worker's procedure, work progress estimation method and motion planning method based on them are proposed.

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Many studies on baseball bats have been carried out in the world. And a lot of useful knowledge for development of bats, e.g., coefficient of restitution, trampoline effect and so on, have been obtained. However, effect of clamping conditions on hitting performance has not been clarified yet. Therefore, we have developed an evaluation system for coefficient of restitution on baseball bats using three kinds of clamping devices for bats, that is, “rigid clamp”, “rotating-free clamp”, and “free support”. In this paper, the evaluating system and some examples of experimental results have been reported. We concluded that differences in clamping method of metal baseball bat scarcely affected evaluating results of coefficient of restitution on hitting. The rotating-free clamp is well suited to the system from the viewpoint of the simplicity of experimental operation and adequacy of the data.

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Plastic film, formed as wound roll, is often stored and transported. Then the in-roll stress may vary over time due to viscoelastic property of the film. As a result, it could lead to wound roll defect such as slippage or blocking. One of the causes is that the film creeps in radial direction and circumferential direction depending on the stress and the temperature of the wound roll at a given time. It is important to consider the viscoelastic property on theoretical estimation of the in-roll stress in order to prevent the defect efficiently. In this study, a polypropylene film is applied as a plastic film and the creep compliances are measured by compression/tensile creep tests under various conditions. From the experimental results, it is shown that the film has anisotropic creep behavior, which depends on stress and temperature. Additionally, it is shown that stress and temperature significantly affect the radial creep compliance and the circumferential creep compliance, respectively. Furthermore, to estimate the creep compliance values on arbitrary stress/temperature condition, a prediction model expressed by the creep function is obtained based on the measurement values, which is able to apply on winding model.

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Plastic film, formed as wound roll, is often stored, transported and heat-treated under the various temperatures which can be different from the winding temperature. Then the in-roll stress may vary over time due to thermal strain and viscoelastic property of the film. As a result, it could lead to wound roll defect such as slippage or wrinkling. Therefore, it is extremely important to theoretically estimate the in-roll stress in order to prevent the defect efficiently. In this study, a thermal-viscoelastic winding model is presented. On the winding model, creep function which is extended to consider dependence of stress/temperature on the viscoelastic property and entrained-air effect, is applied on viscoelastic component of thermal-viscoelastic mechanical model. From verification experiment on which a polypropylene film is used as a plastic film, the result indicates that the predicted values generally correspond to the experimental values on the radial stress. Additionally, relationship with the predicted time variations of the in-roll stress and the wound roll defect is showed.

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Small gears with high precision are necessary to satisfy the requirements in strength and noise of compact geared motors. Nicks are formed accidentally in the manufacturing process of gear and they have bad influences on the strength and noise of small gear. Therefore nicks must be removed in the final process of manufacturing. However it is difficult to remove nicks from surface-hardened small gears after heat treatment because the tooth groove of small gears is narrow. Therefore tool and method suitable for nick removal are necessary. In order to solve this problem, a gear-shaped tool composed of alumina-fiber-reinforced plastic (hereafter called ALFRP) and a removal method of nicks from small gears using it are proposed in this report. The manufacturing process of ALFRP gear-shaped tool is developed. ALFRP gear-shaped tool is rotated with a work gear and is oscillated in the axial direction in the proposed removal process. An experiment is carried out, in which the proposed removal method is applied to the surface-hardened gear by carburizing. The experimental result shows that the ALFRP gear-shaped tool and removal method are effective to remove nicks from surface-hardened gears.

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The previous paper showed that helical gears with small number of teeth and large helix angle manufactured by form rolling have higher load capacity and more efficiency than hobbed ones. However, they have large deviations on tooth trace. In the present paper, a new method for reducing the deviations is proposed after a mechanism of causing the deviation being realized. As a result, it was found that a periodic fluctuation in the working pitch radius during form rolling process cause the helix deviations. On the basis of the knowledge, a new form rolling method was proposed. This method consists of two processes which give the shift of a half rotation phase of a work-gear to cancel the fluctuation. It was confirmed that proposed method enables to reduce the helix deviation.

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To predict precisely the tooth surface strength of transmission gears has been a very important issue in developing a new vehicle-transmission with high reliability, because failures such as pitting or spalling on the tooth surface have recently determined the gear life. Mass produced transmission gears have some unevenness in helix deviation between the teeth, which is caused by runout of the cutter arbor, heat treatment distortion, assembly errors, etc. It is important to clarify quantitatively the influence of the variability in helix deviation on the tooth surface strength of gears; however, no report on the subject has been published. In this study, gear surface fatigue endurance tests were carried out using carburized gears with five types of uneven helix deviation between the teeth. The results were examined, and the author introduces a new parameter, “Modified Hertzian pressure” that is based on cumulative fatigue damage rule on the tooth surface and the variation of Hertzian pressure during gear mesh. It is demonstrated that tooth surface fatigue life can be estimated quantitatively using this parameter. Based on the information obtained, the influence of the variability in helix deviation on the tooth surface strength is discussed.

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The wear of ultra-high molecular weight polyethylene (UHMWPE) cup is a major problem of artificial hip joints that are used in replacement arthroplasty. A recent study shows that the temperature of the femoral head in artificial hip joints increases to more than 41 °C during walking. The wear of the artificial hip joints increases if it is exposed to a temperature of 42 °C or higher for a long time. The purpose of this study was to investigate the influence of bulk temperature on the friction and wear characteristics of artificial hip joints. A pin-on-disc testing machine that shows multi-directional sliding motion was used in this experiment. The pins were made of UHMWPE (GUR1050), and the material of the discs was stainless steel grade 316 (SUS316). The sliding speed was 20 mm/s, the mean contact pressures were 3.5 MPa and 20 MPa, and the test time was 14 hours. The bulk temperature was adjusted to 36 °C and 42 °C with a temperature controller. The lubricating liquid used was calf serum diluted by 25 percent, and it was regularly exchanged during friction experiments. The amount of its exchange was 1 - 4 ml/h, which was controlled by the inflow and outflow of the lubricating liquid in a liquid bath. This experiment has shown that the transfer film in the rubbed area of SUS316 discs decreased with the increase in the bulk temperature. Furthermore, the coefficient of friction and the wear of UHMWPE showed an obvious increase with the temperature rise. Therefore, it was considered that the temperature rise of the femoral head in artificial hip joints is related to the wear mechanisms of UHMWPE in vivo.

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The cutting performance of indexable insert drill that has non-axisymmetrical geometry is investigated. A solid drill that has axisymmetrical and twisted geometry is also used to compare the cutting characteristics. The diameter of drills is 16mm and carbon steel is used as work material. The application effects of MQL that oil mist is supplied from oil holes in the tool are also examined. The temperature of peripheral corner edge of outer insert is measured using a two-color pyrometer with an optical fiber. The tool temperature of indexable insert drill is higher than that of solid drill and it reaches approximately 525°C at highest. On the other hand, the thrust force of indexable insert drill is lower than that of solid drill and it do not change so much with cutting speed. The surface roughness of indexable insert drill is approximately 1.15-5.4μm and this is higher than that of solid drill in each cutting speed. However, it is improved by supplying the oil mist.

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Recently, the achievement of further high-efficiency and high-quality polishing of glass disks as substrates of hard disk drives has been strongly required for reducing the production cost, increasing the storage capacity and downsizing the drive. In order to meet the requirements, it is very important to clarify and improve the polishing properties of suede polishing pads widely used in polishing glass disks and however, a very few researches concerning the pads have been conducted. Thus to overcome the problem, we performed the polishing experiments for glass disks in actual and found that the surface structure of the suede pads is key factor for improving the polishing efficiency. Based on the findings, we proposed a new polishing method that the polishing pad / workpiece contact zone is made intermittent and abrasives are uniformly supplied on the contact zone. As a result, it was found that high-efficiency and high-quality finishing were achieved by the method, as compared with the conventional polishing method.

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This paper deals with the method to prevent cutting burr at face milling of stainless steels. Without laser heat treatment for workpiece, SUS304 caused largest burr height in three type stainless steels. SUS430 was easier to be hardened using laser heat treatment compared with SUS304 and SUS403. As for SUS304, it was possible to reduce burr height. However, it was impossible to prevention burr generation perfectly. As for SUS430 and SUS403, choosing optimum cutting conditions, it was possible to prevention burr generation perfectly. Therefore, laser heat treatment for workpiece is efficient to prevent cutting burr at face milling of stainless steels.

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