To design better molecules for nanometer-thick liquid lubricant films, it is important to understand how chemical structures of lubricant molecules affect viscous properties of the films. To conduct molecular dynamics (MD) simulations for obtaining such understandings, we developed coarse-grained (CG) molecular models of three types of perfluoropolyethers different in end group polarity and main-chain structure. These CG models reproduced the structural properties of the lubricant molecules derived from all-atom MD simulations. Using the models, we then conducted MD simulations of nanometer-thick liquid lubricant films subjected to confined shear between carbon surfaces with random roughness. We confirmed that, for roughness with short correlation length, the shear stress increased with increasing shear resistance among the liquid lubricant molecules due to the polarity of their end groups or the rigidity of their backbones.

We successfully demonstrated the availability of TOF-SIMS (Time of flight-secondary ion mass spectroscopy) in studying the thermal decomposition of the lubricant film on magnetic head slider under heating in the vacuum chamber of TOF-SIMS. By comparing the positive mass spectrum of wide range, we found that the molecular weight distribution of lubricant changed by heating and we confirmed that the thermal decomposition of the lubricant could be accelerated by the catalysis of Al₂O₃.

In the head-disk interface (HDI) of a hard disk drive (HDD), the effects of lubricant deformation on the flying characteristics of a head slider increase as the flying height decreases. Therefore, it is very important to investigate the deformation and flow characteristics of lubricant on a recording disk. In particular, in heat-assisted magnetic recording (HAMR), laser heating of the lubricant induces surface tension distribution and evaporation of lubricant, which may cause deformation of the lubricant film. In this paper, deformation and flow characteristics of liquid nano-film of perfluoropolyether (PFPE) film on solid substrate is investigated numerically and experimentally. Calculation results are compared with experimental results, and validity of the analytical model is investigated.

In recent years, the recording density of hard disk drive (HDD) is increasing remarkably by the development of machine technologies, and the gap between the magnetic disk and the magnetic flying head slider is less than 5 nm. Therefore, the effects of the surface force such as the van der Waals force and the meniscus force have to be taken into account for the design of HDDs. In this study, the mechanical characteristics of liq uid meniscus bridge were experimentally investigated using the meniscus response apparatus. The contact angle of n-tetradecane to the glass surface was controlled by coating the glass surface with oil repellent film. Especially, the effects of solid surface roughness on the dynamic characteristics were clarified.

The slider/disk spacing of magnetic disk drives has been reduced to the near contact phase where the slider/disk contact frequently occurs. Thus, the dynamic performance of slider is important to suppress the vibration caused by the contact. We have introduced a dynamic analysis method for air-bearing slider^[2][3], where the modal parameters, such as modal frequencies and modal damping ratios, are calculated. We investigated and evaluated the slider dynamic performance by using the method, and clarified that the damping characteristics is improved by providing recesses on the air bearing surface. The damping characteristics depends on the depth of recess, and the optimum depth, which maximizes the damping, exists. The damping characteristics also depends on the positional relation between the recess and the nodal line of slider vibration. The recess must be placed far from the nodal line to suppress the vibration by making the recess function efficient. The stiffness and damping distribution on the slider and the wave form of generated force caused by the slider vibration were calculated, and the mechanism of damping generation was examined.

Vibration characteristics of a head slider in hard disk drives in proximity and contact regimes becomes important because head-disk spacing must be decreased to less than 1 nm in order to increase recording density. This study first elucidates head-disk interfacial (HDI) force as a function of static head spacing based on rough surface adhesion contact models and air-bearing force model. Then, selecting the most probable surface force model, microwaviness (MW)-excited vibration of single-degree-of-freedom slider model was simulated by Runge-Kutta method. It was found that the slider snaps-into a contact state at a certain flying spacing but it snaps-out to a flying state when static head spacing is further decreased by increasing heater power. When MW amplitude is large, a large spacing variation which contains low frequency components of less than 100 kHz appears in this unstable region. It was discussed that these calculated results help us understand the mechanisms of various prior experimental evidences.

As new magnetic recording techniques, thermal fly-height control (TFC) and heat-assisted magnetic recording (HAMR) have been investigated in order to increase the recording density of hard disk drives (HDDs). When the spacing is less than about 10 nm, the flow in the lubrication region is close to the free molecular flow, since spacing h is less than mean free path λ of the gas. In this paper, we derived the free molecular t-MGL equation considering temperature distributions and accommodation coefficients at the boundary, for examining thermo-molecular gas-film lubrication (t-MGL) characteristics in several nanometers. Moreover, we show numerically the effects of accommodation coefficients on the basic characteristics of pressures and shear stresses in free molecular region.

Heat assisted magnetic recording(HAMR) is suggested as a technique to realize next-generation high-density magnetic recording. The heat resistance of lubrication film and the diamond like carbon (DLC) film of the magnetic disk surface for the laser irradiation is important factor to realize the HAMR. In this study, we focus on the structural change of DLC film on disk surface by laser heating. Then, we observed the Raman spectra using the surface enhanced Raman spectroscopy. As the results, we confirmed that the structural change of DLC film was reduced with the disk rotational speed and it was estimated that the structural change did not occur on the actual rotation speed of HDDs.

The air flow in a hard disk drive (HDD) is turbulent flow at high Reynolds number about 10⁵ because of high speed rotation of the disks. One of the big issues in the development of HDD is the flow induced vibration (FIV) of the disks and the head arm. Therefore, the investigation on the details of the flow structures and its relationship with FIV are of great engineering importance. In this present work, fluctuating pressure measurement on the inner wall of simplified HDD model was performed changing the parameters; arm insertion angle, arm thickness, disk rotational speed. And guessed the flow phenomena commonly observed an any HDDs by relative evaluation of the results.

Turbulent flow in a hard disk drive model which contained two disks and a RW (read-and-write) arm was numerically analyzed at a disk rotation Reynolds number of about 105. The evaluation of the fluctuating torque revealed that the RW arm may be oscillated at a frequency which had some relationship with fluctuating pressure on the arm surface. The fluctuating pressure was stronger on the leeward surface of the RW than that of the windward. It was further indicated that the fluctuating torque on the RW arm was weakly correlated with the surface pressure fluctuation on the shroud wall.

Currently, hard disk drives (HDDs) are widely used as an auxiliary storage device. HDDs are still in great demand owing to their large capacity and low price. To achieve more recording capacity in HDDs, a more precise positioning accuracy of the magnetic heads is necessary. However, rotation of the disks causes an air-flow between the disks, and the head positioning accuracy deteriorates due to the air-flow-induced carriage vibration. In previous studies, experimental results confirmed that positioning error was improved by attaching linear protrusions on the leading edge of the carriage arms. However, the mechanism of this phenomenon has not yet been elucidated. In the current research, we evaluated the effect of leading-edge protrusions on the flow-induced carriage vibration by finite element method (FEM) analysis.

We report on the experimental study on the complex behavior of the fluid flow induced by a pair of coaxially rotating disks in a non-axisymmetric enclosure, which is commonly encountered in a hard disk drive. We focused mainly on the flow behavior in the disk region based on a series of measurements with particle image velocimetry. The experiment was carried out using refractive-index matched transparent model consists of a pair pf rotating disks with alternately inserted arms in a non-axisymmetric enclosure. The measurements were performed at four angles of the arm insertion on two observation planes at two Reynolds number conditions. Velocity vector fields parallel to the disk surfaces were obtained and we analyzed the circumferential and radial components of the flow velocities. Furthermore, differential parameters including vorticity and shear rate were calculated. The results reveal that the flow is largely influenced by the different angles of the arm insertion.

Recently, amount of information is increasing every year all over the world. Therefore, the data centers which can manage information are increasing too. Hard disk drives are used in the data centers because of their reasonability and high recording density. On the other hand, electric consumption has been increased with increasing data center amount. Therefore, the new structure of a spindle motor applied air bearing is proposed in this study. As new structure of the spindle motor, inner rotor is applied instead of outer rotor. The new structure is expected improve the characteristics of the air bearing. In this paper, the characteristic of the air bearing which is mounted new structural spindle motor was analyzed. In addition, this paper studied theoretically about effectivity of the air bearing. As a result, air bearing friction torque is lower than oil bearing one. In addition, angular stiffness of air bearing is larger than oil bearing.

A mathematical model for calculating the humidity change of the hermetic HDD was presented. This model explains how the water vapor absorbing materials behaves and how the water vapor flows through the hermetic parts of the HDD. This model was calculated by numerical simulation. Feasibility of this model was evaluated by comparing the simulated results with the measured values. This model can be used to predict the humidity of the HDD under arbitrary environmental conditions.

A highly precise positioning actuator for a Scanning Prove Microscopes (SPM) and a magnetic recording evaluation system has been developed. The positioning actuator is consisted of a displacement amplifier mechanism and a stacked piezoelectric element. In this paper, we propose a new two dimensional positioning actuator composed of two pair of piezoelectric actuators, parallel links with square support spring and a positioning stage. The control performance and the positioning accuracy are verified. Furthermore, the influence of the tracking actuator on the transient phenomena of the stacked piezoelectric element precise positioning stage has been discussed.

We proposed a method to determine the end of the positioning phase based on a support vector machine, and the effectiveness of the proposed method was verified by simulation. In this paper, we propose a method that uses both of the hard margin and soft margin to enhance the generalization capability. The effectiveness of the proposed method is verified by using a data obtained from a galvano scanner control system.

A new planetary gear using plastic gear and control system for photo-conductor (PC) drum drive in production printing is proposed. In order to obtain high image quality at low cost, driving technology using plastic gear to keep the PC velocity constant is needed. A feedback (FB) and feedforward (FF) controller is adapted to achieve ever higher performance. This paper proposed a new FF control strategy for reducing the periodic disturbance that is caused by transmission error of the planetary gears. The proposed control strategy reject the periodic disturbance based on switching scheme and open-loop observer. The advantage of proposed method is that periodic disturbance can be rejected without sacrifice of feedback performance. An experiment on prototype is carried out to verify the control performance. The experiment show that 90[%] periodic disturbance is reduced by the proposed control algorithm.

This paper proposes a grasping force control system by using a series-elastic actuator for master-slave systems. In the proposed system, the grasping force is controlled by controlling the fall velocity of the grasping object to be a very small value near zero, for example 1 mm/s. During slipping with very low velocity condition, the applied force to the object is kept near the minimum value to hold the object. This gives information about what is the minimum force to keep the object held. To evaluate the validity of the proposed system, it is implemented to a two-stage series-elastic actuator system. The experimental results showed that the falling velocity can be controlled to be around 1 mm/s and that an appropriate minimum force to grasp the object can be successfully found.

Dew condensation from Heated Papers in Multifunction Peripherals (MFPs) is a chronic problem. This paper attempts to solve the dew condensation problems such as abnormality image. The authors estimated the Dew condensation distribution of MFPs by the new developed dew condensation simulation, and searched the paper contact pattern by paper transportation simulation. The both results show that the abnormalities generate when dew condensation on face contact parts with paper exceed the value specified. To consider both results, the authors prepared the evaluation standard of dew condensation abnormalities generations. This technology enables that effective measures for MFPs dew condensation problems without actual prototyping.

Page turning technology is widely used in many applications, such as Automated Teller Machines (ATM) to deal with passbooks, automated machines to convert paper books to electronic books, and so on. Among them, ATM especially requires high reliability because ATM is used in unmanned operation. In this paper, a new page turning roller is developed for a high reliable page-turning process on ATM. ATM has to turn a high stiffness cover page and low stiffness inner pages of passbooks. The developed page turning roller has the ability to change the increasing rate of its pressure force during rotation. By applying the developed page turning roller, a page turning machine for ATM can stably turn cover pages and inner pages of passbooks.

In this study, we fabricated poly (lactic acid) nanosheet, that thickness is less than 100 nm, by using micro gravure printing. Nanosheet has several unique characteristics compared with bulk films, the large aspect ratio of such nanosheets leads to unique physical properties, such as transparency, noncovalent adhesion, and high flexibility. We investigated the effects of film transportation speed, rotational speed of micro gravure roll and solution concentration on film thickness of nanosheet fabricated by micro gravure printing. Moreover, physical property of nanosheets fabricated by micro gravure printing and spin coat methods were compared.

In recent years, roll-to-roll-printed-electronics have attracted attention to manufacture flexible devices such as polymer electrolyte fuel cell or lithium-ion secondary battery. The technology can mass-produce flexible devices bacause the technology continuously forms electric circuit by dropping conductive ink on film which is transported by many rollers. However, the technology has not been put to practical use bacause there are many problems in this technology. Where, trough and wrinkling gives an example as the defects which is occurring in the process. If these defects occur on the film in manufacturing process, performance of formed circuit significantly decreases. Consequently, we need to prevent defects. Therefore, in this study, we suggest preventing method of these defects by image recognition technique as a pre-stage to construct of mechanism.

Plastic film is produced by Roll-to-Roll system. In this system, Plastic film could be stored in a small space by wound into a roll. However, in roll defect causes big economic loss. Especially gage band still remains an open research problem. Furthermore, in recent years, plastic film is necessary to re-consider the wrinkling and the slippage because it tends to thin. These problems depend on the stress state of the winding roll. Therefore, it is necessary to predict the stress state to prevent defect occurring wound roll. In addition, internal stress of wound roll will be changed due to viscoelastic properties over time. In this study, optimization of winding condition and internal stress analysis of wound roll considering viscoelastic property and web thickness distribution is presented and experimentally verified at a constant tension. As a result, the predicted values are in agreement with the measured values.

How a wound roll stress distribution will change when a nip roller is used during winding, and how a wrap angle around the nip roller will affect the roll stress distribution, these are investigated by simulating a winding process of two-dimensional models composed of a web, winding core and nip roller using a FEM software. The results show that the roll stress distribution is classified into the following three groups, (G-I) no nip roller, (G-II) nip roller with zero wrap angle and (G-III) nip roller with non-zero wrap angle (90, 180 deg.). The roll stresses increase in this order. The stress distribution of (G-III) is almost the same even though the wrap angle changes. Macroscopic slipping patterns (like J-line) of wound rolls indicate that large friction forces due to a nip load pull the outer layers to the core rotational direction.

Winding defects such as “Telescoping”, “Axial wrinkle”, and “Core mark” reduce the production yield of roll to roll manufacturing process. This paper describes the mechanisms of typical winding defects, and the design method of winding tension for preventing winding defects on a highly functional film at production line.

The plastic film is used by various purposes and attention is attracted as a wrapping materials and function materials. We feed web wound off by a roll shape and convey it with a roller, added value, and finally wind it in the manufacturing factory. It's requested to wind a web with no problem at a wide width at high speed to offer it for a low price. It's the same meaning as to make a large quantity of defective articles that a defect is included in rewind. It's necessary to control a radius direction stress and a circumference direction stress in the purpose which doesn't give a defect to rewind. The result which tried control is described using simulation software "web master" by this report.

Dragonfly wing is passively deformed in the tip side from the nodus in flapping flight. Wing deformation is thought to correspond to feathering motion. However, dragonfly perform a feathering motion actively. In this study, the effect of passive deformation of the wing on aerodynamic force in flapping flight with feathering motions was investigated using fluid-structure interaction analysis. In this analysis, nodus wing models, which can deform passively, and rigid wing model, which cannot deform, are used. Feathering angle is three types: 0, 20, 40 deg. As a result, when the feathering angle is 20 deg or less, the nodus wings reduce drag force by deformation of wing during downstroke. However, when the feathering angle is 20 deg or more, overlarge deformation of wing decreases lift force. Therefore, the wing with the appropriate level of flexibility can reduce drag force without wasting energy of feathering motion.

In flying insects, dragonfly has special high flight performance. Therefore, in this study, pressure on dragonfly wing surface were measured for understanding much more about the dragonfly flight mechanisms. In particular, the pressure on dragonfly wing surface were measured during gliding and many things were studied for development of the light flexible pressure sensor for using measurement pressure during flapping flight. First, in this pressure experiment, the pressure on the 3 points of the hind-wing surface were measured. In this experiments in glider mode, the pressure on the hind-wing bottom surface generated positive pressure at center and wing tip points. Additionally, the pressure on the hind-wing top surface generated negative pressure at each measured points. Second, in studied for development of the pressure sensor, Ag nanoparticle ink were discharged as wiring material with an inkjet printer and inorganic and organic materials were researched for sensing position of the pressure sensor.

A probe for gap-controlled friction force microscopy (FFM) is presented. Electrodes were added to both the probe and micro electrode parts and normal electrostatic force was generated for compensation of normal force between the probe and sample. In addition, the probe had a see-saw structure and two actuators were fabricated at both ends of the probe in order to generate attractive and repulsive forces. A probe with about 30-μm electrode gaps were successfully fabricated by separately fabricating the probe and electrode parts with spacer structures and assembling them. Moreover, feasibility of gap control was experimentally confirmed.

DNA separation is one of the fundamental procedures for gene analyses. In this study, we developed an electrophoresis microchip that can separate large size DNA (larger than 10 kbp). Our chip had an array of micro-fences in a channel and the separation was achieved based on the principle of size exclusion chromatography (SEC). The SEC-based separation has an advantage that the DNA molecules do not suffer large deformation during the migration in a molecular sieve. This is especially important for the separation of large DNA molecules since they can be easily ruptured by a mechanical stress. To achieve the separation, we conducted the model-based analysis and estimated the optimal electrophoretic voltages for the separation. Based on the estimated conditions, we succeeded in the separation of T4 DNA and λ DNA with our chip.

In recent years, the various studies of trapping and operating single cells by using a microfluidic device have been proceeded. Many conventional methods requires a fluid operating unit outside the device. Therefore, it is difficult to carry the device during operation. In this study, we integrate a small cell trapping device with miniature peristaltic pumps and a chip made by multidirectional photolithography method. The cells on the highly portable device are easily stored in an incubator and observed under the microscope.

In brain science and psychology, one of the most important purposes of recent studies about neural network, biological circuit in brain, is to establish a method of treatment for the central nervous system disease, such as Alzheimer. Neurons in a neural network is stimulated and controlled by visible lights by Optogenetics methods. In this paper, we propose a microchip integrated micro electrodes, micro lenses, and pinholes. The proposed microchip is capable of stimulating a neural network with two focused lights which have different affection to the neuron, and measuring the electrical reaction of the neural network.

In a conventional cell stretching device, it was difficult to observe the initial and in-situ cellular response to stretching. Our group has also been focusing on the development of stretching device to address problems. Although we could measure a cell response by using previous device, the measurement efficiently was not high because it had only 6 culture chambers for measurement. This paper presents a novel cell stretching micro device having micro chamber array for in-situ observation of stretched cell. The presented device consists of elastic micro chambers and SU-8 blocks. The device was fabricated by conventional photolithography. This device has 134 micro chambers, which enable to observe cell response to stretching in the real time. It was demonstrated that the fabricated device could be used to observe in-situ cell responses to stretching.

Recently, flight characteristic of dragonfly has been investigated by many researchers. Dragonfly wing has many micro spike structures on the wing. These spikes exist on two sides of wing. The length and shape of spikes are 10 to 100 micron meters and circular cone. It is important to clear the effect of micro spike structure on characteristics of dragonfly flight. In this study, a plate with micro spikes is fabricated, flow around the plate was carried out flow visualization and the pressure drag and pressure force of the vertical flat plate with micro spikes was measured. As a result of measurement of, the drag coefficient and the pressure force are reduced and flow separation is delayed with the micro spike structure at lower Reynolds number. As a result of, measurement of the drag coefficient and the pressure force are increased with the micro spike structure at higher Reynolds number.

A sensorless noninvasive method for measuring blood viscosity has been developed for a magnetically-levitated centrifugal blood pump. The blood viscosity can be calculated from the measured phase difference between the input current to the magnetic bearing and the impeller displacement. The experimental results using porcine blood, which has a non-Newtonian property, showed the difference between the viscosity measured by a cylinder viscometer and one by the magnetic bearing was 0.3 mPa·s. In the range of 0.5 to 4.5 L/min, the variation of the measured viscosity was less than 0.2 mPa·s. The results indicate the proposed method can be applied to measure the blood viscosity for clinical use.

By integrating the image and position information from intraoperative modality, surgical navigation system and positioning robot, it is possible to realize new precision-guided surgery that does not depend on each manufacturer or specific model. In the study, we have developed a modular navigation system as the software for the "Tensor robot" that measures the knee soft tissue balance during performing Total knee arthroplasty (TKA). In this paper, we report on the Cadaver experiments by using these integrated equipments.

The research aimed at assessing ones postural balance with weighted body against to externally perturbed situations. Kinetic features of postural dynamics under horizontal vibration was investigated in sagittal plane. A perturbation platform was provided to stimulate standing subject in anterior-posterior direction with random vibration. Postural movements and ground reaction forces were acquired by using an optical motion capture system and a force plate mounted on the perturbation platform. Six healthy young male subjects were participated on our experiment. In addition to normal standing condition, subjects carried external weights with a backpack in varieties of 2 kg and 4 kg. The results suggests that backpack loads increases thorax and pelvis inclination to the forward, and requires slightly larger joint moments of lower extremities. Also ranges of the center of pressure translations were diminished under loaded conditions in their control of postural stability.

Measurement system of gait performance for estimation of fall experience of elderly people is introduced. Dual task walk test, in which recall question like the name of Japanese prefecture is imposed on subjects while walking, is conducted. In addition gait parameters such as stride length, walk rate, toe clearance and toe angle of each step are measured using tiptoe-mounted inertial sensor and subject's voice is recorded using voice recorder, respectively. A tablet type of computer with specially developed application is used to wirelessly control the inertial sensor and voice recorder, to count the number of answer and to record the personal information of subjects. The relation between the change rate of difficulty of the question as the required time for one answer and that of the gait parameter is compared. The experimental results show that the change rate of the gait parameter for fall experienced subjects is larger than that of the difficulty of the question and can be used to classify the fall experience of elderly people.

In this paper, influence of surface roughness on feeling of stiffness is investigated in term of touch motion. Five silicone samples, each of which has different surface roughness and the same hardness, were fabricated. Sensory evaluation on feeling of stiffness for the samples was conducted. In sensory evaluations, panelists evaluated stiffness of samples according to two kinds of instruction. One is that panelists evaluated the samples freely. The other is that panelists evaluated them with feeling the surface roughness. From the results of sensory evaluation, it was found that surface roughness obviously affected feeling of stiffness in the case of instruction that panelists evaluated them with feeling the surface roughness. During sensory evaluation, fingertip trajectories and contact force to the samples were measured. As a result, it was found that touch motions differ depending on the instructions for sensory evaluation.

In recent years, the information terminal using a touch panel has become widespread. Touch panel is a device that people touches directly. Therefore, touch feeling of touch panels is important. However, methods for evaluating touch feeling of touch panel surfaces have not been established. In this study, an objective evaluation method for touch feeling of touch panel surface is established based on the tactile sensor system developed in previous studies. Firstly, the sensory evaluations for touch panel samples with different surface treatments were conducted. Next, touch panel surfaces were measured by using tactile sensor system, and evaluation parameters by using sensor output were calculated in order to evaluate touch feeling. Finally, the evaluation parameters were compared with the results of sensory evaluation. As a result, it was confirmed that the tactile sensory system is useful to evaluate the touch feeling of touch panel surface objectively.

This paper presents a tactile device that bends the nail inside to change tactile sensations on the fingertip. We have called this device “Tactile nail chip”. We have developed some prototypes of the tactile nail chip. In this paper, we propose the tactile nail chip made of a quenching ribbon steel. Its structure is simple and it is prepared in various dimensions. Thus, it is easy to attach the device to individual users. Discrimination tests on weight and roughness show the availavility of the proposed device.

This paper addresses a novel force feedback system with Magneto-Rheological fluid, called MR Fluid. Force feedback interfaces, in general, have focused on force display at a contact point. If the force display was extended from a point to surface, applications of the force interaction could be expanded. MR Fluid has characteristics to change its viscosity by magnetic force. Therefore, we developed MR cushion, packed MR Fluid module, with controlling multiple magnets for the surface force feedback system. In this paper, two kinds of surface force feedback systems, by electromagnets and by the magnet position control using linear actuators, are proposed. Finally, several basic performance for these systems are experimented.

In recent years, robots have become familiar to human society. Human beings behave with considering the intention of surrounding persons in daily life. However, a household robot that is currently popular is mostly what it is not possible. Humans have gained a lot of information by the visual information. Thus, by analyzing the human gaze movement, it was possible to estimate the human intention and the state in relation. If this reflected in the behavior of the robot, the robot would run the appropriate support action for human. In this paper, we propose a method for estimation of human attention. As the results, proposed method is possible to perform the estimation of human attention for multiple persons.

A number of traffic accidents have occurred due to human errors such as inattentive driving and drowsy driving. Sleepiness is considered as one of the causes of these traffic accidents. For this reason, establishment of the sleepiness evaluation method during driving a car has been required. In this paper, we measured changes in cerebral blood flow during driving a car using a portable near-infrared spectroscopy device. The results show that oxygenated hemoglobin tends to decrease with the rise of the sleepiness level evaluated by facial expression and that there are negative correlations between oxygenated hemoglobin and sleepiness level in many trials. This suggests the possibility of sleepiness evaluation of a driver using near-infrared spectroscopy.

This paper proposes a novel particle filter using ensemble average. The proposed method is constructed by some particle sets (ensambles) that have different initial hyper-parameters, and performs same operation of a particle filter algorithm to each ensamble. The proposed method can estimate both system states and hyper parameters of the system, by weighted average that is calculated by the logarithm likelihood of each ensemble and the spread of ensembles. In this paper, to compare the conventional particle filter with the novel particle filters, we tests the proposed method under the one dimension nonlinear system and observation model.

Human beings are doing a smooth communication with the auditory, visual and haptic information. Multimodal interfaces are utilized the communication operation assist could be improved by visual and auditory information given the time difference in presentation. In our previous research, the validity of multimodal assists with time difference is experimented by vibration control task for a pendulum. Experimental results show that giving a time difference to the information is effective in the machine operation performance. However, the results depend on the task. Therefore, the experiment is conducted by drive simulation, as a more general task. And in this paper, validity of proposed assist with the tasks is verified, as a first step, the effect on the operating characteristics of each assist. Finally, experimental results show that giving the visual assist is effective in reducing the angle error, and the auditory assist is effective in reducing the position and angle error.

Recently, the remote robot is used in many places. So it must have user interface that can be intuitive and easy to operate. Method of presenting a several images to the operator is commonly used. However, this method is forcing the operator to select the video that is suitable for operation and the operator feel the burden. In this paper, we measured time for three-dimensional pointing using gesture user interface and single video camera. The suitable viewpoint is designed based on dividing the work area that results from video and human property.

The motor imagery is often used for Brain Computer Interface(BCI). Motor execution has visual feedback, however, the motor imagery doesn’t have it. Therefore, BCI is less accurate because of imbalance of brain activity. In this paper, we conducted training of biofeedback that exhibit visual stimuli of brain activity during motor imagery. The result shows that the brain activation by motor imagery approached the activation by motor execution and stability of brain activity was improved. It reveals that biofeedback can be used for accuracy of BCI.

In this experiment, we measure brain activities by Near-infrared spectroscopy (NIRS) when a person is feeling the discomfort caused by vibration. We use a variation of oxygenated hemoglobin (oxy-Hb) as an evaluation index. As a result, two kinds of trends were seen in the brain activities of test subjects. At the other groups increase of oxy-Hb levels is remarkable in prefrontal cortex outer portion, reduction of oxy-Hb levels is pronounced in the medial prefrontal cortex in the other group. These brain reactions were found to be that there is discomfort and the high correlation that people feel the vibration.

In an aging society, the demand of robots to do housework has grown. The robot which automates domesticities is actively studied and developed with the rise of the demand. Folding cloth is a typical burden work and takes a lot of time of the housework. However, to fold clothes automatically by the robot is difficult and take a lot of time due to difficulty of flexible object handling. Therefore, this study proposes a workbench that resolve deflection by control fan in workbench using data of acquired height by xtion. And this study intended to consider method that decrease time of resolve deflection experimentally.