We measured the surface force between a PDMS (polydimethylsiloxane) coated sphere and a PEEK (polyetheretherketone) or Si plane sample using a surface force apparatus that can measure the surface force with ultra-high accuracy. In particular, we focused on the differences in surface force characteristics between air and water environments. The measurement consisted of 4 processes: approach, lift-up, stabilization, and withdrawal processes. Significant differences in probe displacement between air and water were observed in each process. Furthermore, we compared the surface force characteristics between PEEK and Si plane samples. The results revealed that a comparison of the maximum surface forces (or adhesion forces) in air and water showed that they depend on the combination of materials. We deduced that the wettability of the material affected the adhesion forces. Specifically, the low affinity of the two surfaces to water resulted in hydrophobic attraction, while a hydration repulsion acts when one surface becomes hydrophilic.

It has been reported that the friction coefficient of DLC changes when an electric field is applied while the DLC is heated by laser. It has also been reported that the amount of smear generation in head smear generation in heat-assisted magnetic recording also changes depending on the applied electric field. These suggest that the amount of decomposition products of DLC can be controlled by applying an electric field to the friction interface. On the other hand, it has been reported that an amorphous carbon layer is formed when an alkyl diphenyl ether (ADE) lubricant is rubbed. This tribo-film is presumably due to the decomposition of ADE by tribo-chemical reactions. Therefore, we conducted friction tests with pentaphenyl ether (5P4E), 5P4E lubricant, while applying an electric field, and analyzed the tribo-film formed by Raman analysis. The results showed that the formation of an amorphous carbon tribo-film was easily achieved by the application of an electric field.

Heat-resistance of lubricants (Perfluorinated polyether system) for HAMR (Heat-Assisted Magnetic Recording) system of HDD was examined using Near Infrared Raman Spectroscopy (NIRRS) and Surface-Enhanced Raman Spectroscopy (SERS). Heating of lubricant creates fluorescence which disturbs Raman analysis as a result of thermal degradation. NIRRS with 1064nm laser in wavelength is useful to analyze Raman spectrum of heated lubricant because there is no fluorescence in that wavelength region. Another method to avoid fluorescence disturbance is SERS, because enhanced Raman intensity is much larger than fluorescence intensity. As a result, Demnum type backbone structure, C₃F₆O-, is thermally stronger than Fomblin type backbone, -C₂F₄O-. Also, phenyl group improves heat-resistance of lubricant. Lubricant with OH groups and with three or six phenyl groups exhibits high heat-resistance over 250℃. A lot of unknown peaks are observed for lubricant with fluorescence. There peaks are decomposed by-products by heating. Carbon peaks are also observed for decomposed lubricants. Carbonization also occurred by thermal decomposition. Those by-products may create smear which causes head crushing.

In non- axisymmetric hard disk drive (HDD), the flow must go through narrow spaces in between the disks and the arm thereby obstructing the positioning of the read and write arm which is responsible for data sensing. Using a model 2.25 the actual size of 3.5-inch HDD, we compared the flow fields between two intermediate planes in-between the disks and the arm and three mid-planes within the arm, in cylindrical coordinate fixed at a parameter α = 32°, defined as the arm isolation angle which separate the flow between the disk and the shroud opening region. We recorded and analyzed the qualitative flow visualization using a high-speed camera with different resolutions at these planes and revealed their statistical distribution using quantitative particle image velocimetry (PIV) analysis methods. Our methods revealed the radial (v_r) and circumferential velocities (v_θ) normalized by the local disk angular velocity (rΩ) around the arm as it relates to the flow from the disk and after the arm as it affects the flow from the shroud opening region. The results confirmed the irregular flow relating to the arm, disks and shroud opening region which has an immense effect on the rigid body rotation around the hub.

In recent years, hard disk drives (HDDs) have been mainly used in cloud data centers. As the annual amount of data generated has increased significantly, it has become essential to increase the capacity of HDDs constantly. Therefore, heat-assisted magnetic recording (HAMR) is expected to be a next-generation recording method. Currently, FePt media is used for HAMR, and there are two concerns. One is that the FePt media makes it difficult to achieve high BPI because it is difficult to achieve both the small grain and the high degree of order. The second is reliability problems because the FePt media has a high curie temperature of approximately 400°C. Specifically, there have been reports of a deterioration in the shape of the near field transducer (NFT), an occurrence of head contamination, and a deterioration of the head DLC (diamond-like carbon). On the other hand, analytical studies have shown that the NFT temperature during writing is below 300°C, so the mechanism of the above phenomenon is not clear. In this paper, to elucidate the heat transfer mechanism between the head and the media, we compared the thermal analysis results of the head-media model using the heat transfer coefficients from published papers with the data from published papers. As a result, it was concluded that the heat mainly transferred from the head to the media and that the head temperature was higher than the media temperature.

In recent years, hard disk drives (HDDs) have been mainly used in cloud data centers, and their data structure uses the log-structured merge-tree (LSM-Tree) which undergoes many rewrites, resulting in a workload requirement of 550TB write/year. A 5-year product warranty is currently required, and there seems to be a desire to extend it to 6-7 years in the future. Therefore, reliability is one of the most important characteristics of HDDs. On the other hand, because current head media spacing (HMS) is less than 1nm, intermittent head to disk contact frequently occurs, increasing the risk of head wear, head smear, media scratches, and so on. As countermeasures, many studies have been conducted, including research on soft contact detection methods, bouncing, research on head protrusion, bouncing and surfing during touchdown, and so on. However, there seems to be little research on the mechanisms of intermittent contact and repeatable HMS fluctuations. In this paper, we calculated the static change amount of slider pitching to keep the slider pitch angle constant with respect to the disk when following the disk waviness. We also calculated the dynamic behavior of slider pitching when the change amount is input using a one-degree-freedom model. As a result, we found that one of the factors in HMS fluctuation was the phase delay of slider pitching, and its parameters were extracted.

Currently, HDDs are mainly used as storage devices in data center servers. However, it is known that the vibration caused by the sound pressure of the HDD cooling fan in the server increases the positioning error of the head and reduces the read/write speed. In a previous study, adaptive control was used to reduce the vibration, but it was found to be difficult to reduce the vibration when the disturbance frequency changed. In this study, the modal parameters of the filter in the first stage of the adaptive control in the previous study were changed as needed to design a control with a high reduction effect

To investigate the effect of belt width on the lateral motion (tracking) of the belt, the lateral motion of belts of various widths was measured in a two-roller belt system with misalignment. Furthermore, based on the experimental results, a prediction equation for the tracking rate considering belt width was proposed. The results suggest that belt width and roller diameter are related to the lateral motion of the belt.

In the final stage of film production, films are typically wound to form a roll, and it is known that air is entrained into the roll during the film-winding. Since the amount of air is one of the factors causing winding defects such as slippage and wrinkling, it has been desired to detect to the air layer thickness non-destructively and quantitatively. In our previous study, we proposed a non-destructive inspection of film rolls by using optical coherence tomography (OCT), which is a three-dimensional imaging technique based on low coherent light interference, and demonstrated that OCT can visualize in-roll structures of film rolls and detect air gap sizes in the film roll quantitatively. However, the air layer thickness cannot be detected if the thickness is smaller than the spatial resolution of OCT. In the present study, we propose a method to detect the air layer thickness smaller than the spatial resolution of OCT. To validate the method, we made film roll samples with air layers smaller than the spatial resolution of OCT by manually winding a film and applied the method to the samples. The experimental results showed that the proposed method can quantitatively detect the air layer thickness in film rolls with sub-microscale and showed a significant difference between air layer thicknesses of film rolls made by soft and hard windings. Although further validation under controlling the film-winding condition is needed, the proposed method will be a promising inspection to prevent the occurrence of winding defects.

In recent years, not only paper and plastic films but also metal foils have been increasingly transported and processed by roll-to-roll (RtoR), and depending on the transport speed and tension, wrinkles and slips can be occurred during transport. In order to elucidate the slip mechanism, we built an experimental machine that can vary the tension difference between the front and rear rollers while transporting the copper foil, calculated effective friction coefficients for each roller diameter and transport speed, and compared them with theoretical formulas. When the roller diameter is large, both results agree well, however when the roller diameter is small, the experimental values deviate from the theoretical values to a greater extent, and it was found that slipping is less likely to occur than the theoretical formulas.

Urinary incontinence in nursing homes is an important issue for patient comfort and hygiene. One of the most important issues is the accurate prediction of urinary bladder voiding time. In this study, we propose a method to estimate the expected time of voiding at an arbitrary time by obtaining the parameters of an bladder urine accumulation-urinary urge transfer model that takes into account the influence of the dynamics of body water content from the amount of urine stored in the bladder measured by an ultrasonic sensor.

In recent years, visual and auditory information presentation technology has been used for surgical simulation in the medical field, but there are few practical examples of tactile information presentation technology, which is important for safe and accurate surgery and palpation. In particular, measurement and presentation of tactile information at a remote location is needed for the practical application of remote palpation. In this study, we focused on the mechanical phenomena in the finger abdomen during the tracing motion and developed a device to present the sensation (tracing sensation). Specifically, we observed mechanical phenomena during tracing using OCT and force sensors. As a result, it was suggested that there are differences in the contact position and the change tendency of contact force depending on the hardness of the sample. In addition, we designed a system for presenting tracing sensations to a flexible object equipped with a sheet structure to realize these phenomena using a geometric model and confirm the operation of the prototype device.

In recent years, it has been acknowledged that the reduction in muscle mass due to aging can result in various health conditions, such as locomotive syndrome. It occurs when the breakdown of skeletal muscle proteins exceeds their synthesis, resulting in loss of motor function and the possibility of becoming bedridden. Currently, there is no specific treatment available for this condition, and research is actively being conducted to establish an effective treatment. It is important to note that these experiments are conducted in a controlled environment and may not necessarily reflect the effects of the drugs on humans. In conventional research on new drug development, animal experiments using mice administered with drugs or genetically engineered mice have been common. The study aimed to establish a muscle disease model that is more reproducible without the need for drugs or genetic manipulation techniques. To achieve this, a threedimensional artificial muscle was prepared using a C2C12 cell line, and culture experiments were conducted in a microgravity environment using a clinostat. The usefulness of the sealed vessel was confirmed by conducting a control experiment with normal culture performed in a 6-well plate. The experiment confirmed that the clinostat had a significant impact on the muscle organoids, resulting in a substantial reduction in contractile force. Additionally, the culture in the closed container showed no significant difference from the culture in the 6-well plate, indicating that it was possible to culture the organoids in an environment similar to that of normal culture.

The safety and reliability of the vascular access puncture are fundamental in hemodialysis treatment. Placement of the cannula needle becomes problematic when the vessel condition becomes hard for advanced prediction. Improving the quality of the needle placement, in the indication of the ultra-sound guided puncture, for instance, proper insertion depth sensing is necessary to identify the needle tip location. This manuscript critically discusses measuring the needle insertion depth using a laser ranging and an inertial sensor mounted on the puncture needle. Experimental equipment was developed, which consisted of the laser displacement sensor and the tri-axis accelerometer mounting on the needle-holding jig. The jig provides a variety of insertion angles as the experimental condition and ensures smooth puncture movement in manual operation. The proposed method successfully assesses insertion depth by correcting the effects of sensor mount alignment to some degree, but its tolerability and calibration procedures still need to be improved.

Quantitative evaluation of body movement is necessary in various fields, such as objective evaluation of patients' recovery progress in rehabilitation and skilled operations of technicians. In particular, hand movements play a significant role in daily life. In previous studies, a ring-type sensor that can estimate fingertip force by measuring tendon tensions without interfering with tactile sensations was proposed. In this paper, we expanded the mechanical model with one ring-type sensor on the proximal phalanx to the model with two ring-type sensors on the proximal and middle phalanges and evaluated the model's validity. To evaluate the model, we performed experiments to synchronously measure fingertip force, ring-type sensor outputs, and PIP and DIP joint angles. Applying the acquired data to the model and setting the appropriate parameters, it was confirmed that the fingertip force can be estimated with the proposed mechanical model. In the future, to improve the model, it is necessary to compare the estimation accuracy to the methods in previous studies that estimate fingertip force with ring-type sensors and to establish a parameter determination method.

Chronic obstructive pulmonary disease (COPD) has been attracting attention as a respiratory disease that should be prevented because both the number of patients with COPD and the number of deaths associated with COPD are increasing, and a method that can help diagnosis in the home environment is desired. Therefore, this study introduces a mask-type device that piezoelectric ceramics installed in the mask and constructs a model considering the physical relationship between human respiration and the voltage measured through the piezoelectric ceramics. Furthermore, by applying signal processing based on this model, we will attempt to realize a pulmonary function evaluation system that estimates FEV_1.0%, which is used as an index for detecting obstructive disorders.

Japanese infrastructures that built rapid at economy growth. Inspection and repair of infrastructures are required. But shortage of engineers and dangerous workspace. Particularly wall surface is one of the hardest environments to inspect and repair by human. Thus, we think to develop the robot that inspect, and repair wall surface automatically. Our purpose to develop the small wall climbing robot for inspecting and repairing wall surfaces. We consider multi-legged robot with negative pressure adsorption mechanism. Multi-legged robot can walk on uneven terrain. We would like to know both performance of adsorption mechanism and walking method. We have developed simulation for evaluating the walking method that can walk on wall dose not decrease the adsorption force and develop experiment system for evaluating the exhaust system for predicting the adsorption force from adsorption mechanism

In the marketing field, visual information significantly influences the purchasing behavior of consumers. This study focuses on the relationship between product display and visual information, aiming to provide an objective index of attention attractiveness that can guide layout decisions and improve package designs. We propose a system for estimating the area of interest (AOI) in a product display using saliency detection, a typical method reflecting bottom-up attention. The estimation system uses images captured in an actual store. Employing a saliency detection method based on differences in spatial frequency spectra, the system calculates the saliency of each AOI for each product area and outputs it as an estimate of the AOI . We experimentally measured the eye gaze of 12 subjects to assess the adaptability of the system and the impact of top-down attention. Subsequently, we compared the estimated system with the actual gaze distribution. The results showed no overall correlation; however, a positive correlation was observed among the experimental collaborators, suggesting the potential for estimation. Furthermore, a positive correlation was noted in many non-planned purchases; however, this correlation decreased in planned purchases. These findings indicate that increased top-down attention results in an attention pattern different from that of the estimation map.

In this study, the primary objective was to quantitatively assess the impact of various package colours on the flavor perception of chocolate confectionery and on the emotional state of consumers during consumption. Experiments were conducted to appraise the effects of diverse package colours on the product image, overall impression of the packaging, and influence on the eating mood. The product image evaluation experiment indicated that orange, yellow, red, and brown packages elicited perceptions of milkiness, associated with sweetness and mildness, whereas purple, green, and black packages elicited sensations of bitterness, linked with a bitter taste and difficulty in consumption. In a mood evaluation experiment during consumption, the red package elicited a pronounced perception of the milkiness of the chocolate, whereas the black package triggered a distinct perception of bitterness. The results from biometric indices demonstrated that the black package condition had a stimulating effect on the pupil diameter, whereas the red package condition had a stimulating effect on the skin conductance response (SCR). This suggested that the vivid recollection of chocolate taste induced by the packaging might contribute to arousal, and the response to biometric indicators varied based on the perceived taste of the chocolate.

Adjusting the driver seat to an appropriate position is crucial not only for ensuring the necessary visibility for the safe driving and reducing driving-related fatigue but also for facilitating comfortable driving operations. In this study, we examined the correlation between the front and back positions of the driver seat and the safe driving behavior, elucidating the impact of seat positioning on driver safety by comparing and evaluating changes in the driving behavior resulting from alterations in the front and back positions of the driver seat. We experimentally investigated the relationship between the front and back positions of the driver seat and the safe driving behavior. We systematically varied the front and back positions of the driver seat, used a head-mounted display to create a driving simulator, and trailed a car moving at a constant speed on a figure-eight driving course designed to simulate highway conditions. The evaluation focused on the driving speed and distance between vehicles. Our findings revealed significant differences in the driving speed and distance in the front and back positions of the driver seat, indicating that the front and back positions of the driver seat indeed influenced the safe driving behavior.

The purpose of this research is to develop a posture estimation method of nursing care givers using plantar pressure distribution. Since nursing care with improper posture can cause some diseases like a lower back pain, care givers had better be instructed about a proper posture of a nursing care in advance. Some researches of posture estimation of care givers have been conducted; however, some sensors were required to be attached to the care givers’ bodies for the motion measurements. Conversely, our proposed posture estimation method does not require any sensors to be attached to the body; a pressure sensor sheet is only required to be settled under the nursing care area, and the posture is estimated from plantar pressure distribution. That is, the height trend of the lower back is estimated from change in plantar pressure distribution by using a summation of the pressure distribution. The reason of estimating the lower back height is that in actual nursing care, lowering the lower back is important for preventing the back pain. In the experiments under the assumption that a care giver assisted a care recipient who moved from a bed to a wheelchair, a participant’s lifting up motion of a weight were conducted, and the postures of the participant were estimated by using the proposed method. As a result, the height trend of the lower back of the care giver were estimated correctly.

In recent years, augmented reality (AR) has been used in fields such as work support. Because AR overlaps the real environment with a virtual environment, the visibility of the real and virtual environments may deteriorate depending on the manner in which the virtual environment is displayed. Therefore, research has been conducted on view management to maintain and manage the visibility of the composite result of the real and virtual environments, and methods to appropriately position virtual objects in relation to the real environment have been proposed. However, the combination of the background color of the real environment and the color of the virtual object may result in low visibility, even when the object is displayed at the appropriate position. In this study, we investigated the effects of color schemes on the visibility of the annotation user interface (UI), aiming to clarify the color schemes with high visibility against the background color. Paired comparison revealed a positive correlation between visibility and differences in brightness and color for many background colors. Based on this result and the World Wide Web Consortium/Web Accessibility Initiative (W3C/WAI) findings that the visibility of color schemes with a brightness difference of 125 or more between the background color (the UI color in the experiment) and the text color and a color difference of 500 or more is high, a positive correlation was noted for many background colors. Therefore, we considered that the visibility could be improved by setting the UI color with the largest difference in brightness and color between the background color and the text color and setting the text color with the largest difference in brightness and color between the UI color and the text color. The results of an experiment to evaluate the proposed method showed that the visibility scores for the conditions set by the proposed method were significantly higher, and no significant difference was observed in eye fatigue, suggesting that the proposed method might improve visibility without having a negative effect on eye fatigue.

In this study, we evaluated a method for eliciting user attention without their conscious recognition. We focused on exploiting characteristics of the human visual field to determine the effectiveness of attention induction by rendering a portion of the visual field at an imperceptibly high resolution as the inducing stimuli. The proposed method utilizes a head-mounted display that aligns with the visual field characteristics of the user and presents a resolution accordingly. Moreover, areas intended to guide attention are maintained at a high resolution as guiding stimuli. To assess this approach, we conducted an experiment with 10 participants, measuring eye gaze and evaluating attentional behavior in a visual search task with and without the presentation of guided stimuli. The results indicated attention-inducing effects in certain directions of the visual field. Additionally, the findings suggested the possibility of latent attention being directed towards the guided stimuli, even without influencing conscious gazing behavior.

In this study, we investigated the impact of perceptual and emotional changes associated with field-of-view (FOV) expansion during straight-line walking on the gait of pedestrians. We developed an interactive FOV expansion system that varies FOV with the walking speed of pedestrians and compared it with walking under conditions where the FOV remains constant. The results of the experiments revealed that pedestrians who prefer walking at relatively fast speeds exhibit gait changes resembling brisk walking to maintain a broad FOV. On the other hand, pedestrians who prefer a leisurely pace tend to adopt a wide and cautious gait to avoid excessive or insufficient FOV expansion.

Furthermore, in the former group, an increase in dynamism, openness, novelty, and enjoyment during walking was observed, along with a notable shift in post-walking mood towards an activated direction. These findings suggest the potential for interactive FOV expansion during physical activity to exert effects akin to mental doping. In the future, our objective is to optimize the system and explore suitable control methods for adjusting the presented FOV. Simultaneously, we aim to narrow down the triggering conditions for the effects induced by FOV expansion and strive to enhance the generalization performance.

In recent years, as the information society has advanced, the demand for programming learning to develop information technology human resources has increased. However, challenges such as the inability of certain individuals to sustain learning persist. Visual-based learning systems have been developed to address these issues and have demonstrated enhanced learning efficiency than traditional methods. Nevertheless, proficiency in text-based skill acquisition remains essential. This study focuses on a system that generates code based on visually implemented programs. In particular, we introduced real-time syntax highlighting in the code output and assessed its effectiveness. The results indicated that the system incorporating the proposed method exhibited significantly higher subjective learning efficiency and enhanced applicability of skills and knowledge acquired through the system. Moreover, the level of confusion during learning was notably lower compared with that in conventional methods. The introduction of the proposed method facilitated a clearer understanding of the relationship between the operation target block and the output code, thereby reducing confusion and increasing learning motivation. This implies that the proposed method holds the potential to create a programming learning environment with heightened motivation and reduced confusion.

To record human hand techniques and shear them to humans and robots are our final goal. In this study, we develop a nail-colored tactile sensor that records human fingertip force and investigate tactile score as a method for recording time-series tactile data. Regarding the nail color tactile sensor, there was a problem in which the relative position of the nail and the sensor deteriorated each time the sensor was attached and detached, which deteriorated the estimation accuracy. We investigated the collection of training data and ways to improve estimation accuracy using the model. As a result of the investigation, we confirmed that the accuracy of vertical force estimation can be improved by attaching and detaching the sensor seven times when acquiring learning data and by using Xception. We also recorded vertical force using this sensor, converted the time series data into tactile score, and reproduced fingertip force. As a result, I found it a little difficult to reproduce the finger force while visually viewing the tactile score. In the future, we will verify the effectiveness of the method in transferring skills between humans and humans and between humans and robots.

A micro-meter-sized droplet called a satellite droplet can be generated when the capillary bridge is broken. This method of generating the satellite droplet is called the capillary bridge breakup method. The droplet oscillates using surface tension as a restoring force and eventually becomes spherical. The frequency and decay time of the oscillation can be related to the surface tension and viscosity of the test liquid, respectively. Using this relation, we have developed a method to obtain viscosity and surface tension values from the surface tension oscillations of the satellite droplet. The previous measurement results for Newtonian fluids such as water and linear hydrocarbons are in good agreement with literature values. In this study, the applicability of this method to milk, a colloidal solution that might exhibits non-Newtonian properties, was examined. As a result, several behaviors not seen in Newtonian fluids were observed, such as the formation of extremely small droplets and multiple droplets. Furthermore, simultaneous measurement of viscosity and surface tension was possible for several dilutions of milk.

Capillary bridge breaking method (CBB) is known as a satellite droplet generation method. It is known that the oscillation is induced by surface tension during the generation process. Due to its high reproducibility of experiment, a method for evaluating physical properties using CBB has been proposed, and CBB is also used to validate a performance of numerical simulations. In this study, we performed numerical simulation of surface tension oscillation using OpenFOAM. Then we validate the performance of OpenFOAM by comparison with experimental oscillation data and physical properties.

Microscopic work done under a microscope can be a very inefficient process. There are many delicate tasks where unskilled operators often make mistakes. For this reason, time is wasted in learning how to use microtools that are suited to the size and characteristics of microscopic objects. In this study, a powerless displacement reduction mechanism using magnetic force have been developed. The developed mechanism can reduce fingertip displacement from a few centimeters to several tens of micrometers with a single mechanism, and the full stroke and displacement reduction rate can be adjusted by the gap between the magnetic poles. The usefulness of precision tweezers constructed with this device for microscopic work has been investigated. -

In this study, piezoelectric thin-film earphone speakers were designed, fabricated, and evaluated. To enhance the acoustic output, the device design was optimized by finite element analysis. The two types of prototype speakers were fabricated using the piezoelectric PZT thin film deposited on a stainless-steel substrate on which polyethylene films were covered as a diaphragm membrane to improve the acoustic output. The vibration displacement and sound pressure of the speakers were measured. We confirmed that the sound output was improved by using polyethylene film as the vibrating film in both of the two shapes. The speaker with the taper cantilevers achieved a sound pressure level of 90 dB at 4 kHz in the rubber tube.

In manufacturing equipment, there are high expectations for so-called in-line monitoring technology, which detects damage while the original function of the equipment is operating from the viewpoints of real-time performance and speed. This study proposes a non-contact acoustic emission (AE) method for in-line monitoring. AE is weak elastic wave generated by cracks, rubbing and other damages in materials. We focused on the fact that AE waves originating from the bearings of rotating rollers propagate through the cylindrical body as guided waves and also propagate slightly into the air. The experiment showed that an air-coupled ultrasonic sensor inclined to the object could detect AE waves resulting from damage inflicted on the outer ring of a rotating bearing in a non-contact manner. This technique is promising for an inspection technology for manufacturing equipment or industrial machinery where direct sensor installation is impossible.

There are currently 730,000 bridges in Japan. Although in 2018, 25 % of the road bridges had more than 50 years old, an indicator of the aging of the transport infrastructure, this indicator will reach 63% in 2033. Furthermore, human resources, such as professional workers and engineers working on the inspection and maintenance, are gradually decreasing. Therefore, adequate inspection and maintenance are not always conducted; this is considered a serious social problem in Japan. To solve this problem, we have previously proposed a self-powered vibration-based structural health monitoring system. The core part of the system is the novel vibration-sensing device discussed, which implements a giant magnetostrictive material. In this paper, the structure of the sensor is investigated to solve the problems of the prototype device before. The bridge girder on which the sensor is installed is tilted by several degrees, so the pressure does not act evenly on the material. Therefore, we propose a structure using concave-convex spherical contact. The experimental results showed that the bending stress could be reduced and the generated power could be improved compared to the previous prototype sensor.

In this paper, we propose a direction estimation method using a self-rotating inertial sensor and a distance estimation method using an LSTM-based deep learning model to improve the positioning accuracy of two-dimensional moving objects such as AGVs. By rotating the inertial sensor, the direction is accurately calculated by correcting the sensor offset. With this method, it was confirmed that the direction error was reduced from 52° to 5° in 30 minutes of evaluation in a stationary state. In addition, we developed a distance estimation method using a deep learning model based on the information from the inertial sensor. We evaluated it using an AGV on a rectangular path and confirmed that it can estimate the moving distance with an accuracy of 0.7%.

Analysis methods for non-Gaussian stochastic processes are required for various applications in the areas of reliability analysis, signal processing, system identification, and so on. On the other hand, most of the conventional studies in terms of non-Gaussian random excitation have been limited to theoretical vibration response analysis, and non-Gaussian vibration experiments using actual systems are still in the developing stage. In this paper, a non-Gaussian random exciter using a waveform generation method based on the Cai and Lin model is developed, and the probability density shapes and power spectrum of the waveforms output from the actual shaker were evaluated. From the evaluation results, it was found that the developed experimental setup can output waveforms that accurately follow the given probability density function and power spectrum, confirming the basic operation as a non-Gaussian random exciter.

Infrastructure built in 1950s has exceeded its service life and has become a social problem because of its deterioration. To solve the problem, it is important to expand inspection technology and to make efficient repair plans for infrastructure such as water pipes and bridges. Especially research and development of inspection technology related to digitization using ICT is expected. In a previous study, we conducted experiments using a IoT sensor to determine the mean square value of acceleration for rings which have different pipe thicknesses and observed that the mean square value of acceleration changes as the pipe thickness changed. Thus, we will attempt to expand the area of application of the inspection method using the mean square value of acceleration for structural components such as beams and others. In this study, we conducted a formulation of the mean square value of acceleration for several structural components and discussed its physical importance in terms of sensing. As a result, it was confirmed that the spatial distribution of the mean square value of acceleration for simple support beams converges to a certain shape as the upper frequency limit increases. It was also confirmed that the magnitude of the absolute value of mean square value of acceleration is greatly affected by the maximum mode order.

The 1495 PowerPoint lecture materials on processing technology, AI, and IoT in the subject of "Production System Design" were classified into diagrams, images, and videos, and the maximum evaluation rates in the questionnaire were 17%, 46%, and 48%, respectively. Videos and images were effective as lecture materials. The student IoT usage rate was 70%.90% of students were positive about using AI after employment, indicating that

AI will play a supporting role in the future. We predicted that students' presentation themes regarding the use of IoT would be categorized into manufacturing (34%), agriculture, forestry and fisheries (25%), and lifestyle/environment (31%).Social issues and personal interests played a large role in theme selection. As a result, students' interest in IoT technology has greatly expanded from mechanical engineering to other fields.

This is an activity report in 2023 of the industry-academia-government-finance collaborations for manufacturing DX that has been jointly planned and promoted by Musashino Bank and Toyo University and developed in Saitama area since 2018. As reported in IIP2023, this academy is based on the combination of lecture series for collecting new technology information and exercise series of basic technology mainly concerning on IoT for manufacturing as well as presentations and discussions among participants. In this report, I briefly introduce its activity in 2023 with some considerations on gained knowledge through running this kind of collaborative works.

In the film manufacturing industry, Hiromu Hashimoto et al. previously proposed a formula to predict defects such as troughs and wrinkles occurring during the transport of PET films. However, experiments revealed significant deviations from the expected values within the predicted range after replacing traditional steel rollers with rubber rollers and changing the film to rolled copper foil. To address this issue, I have conducted research and verification of the existing prediction formulas. This formula predicts defects based on multiple parameters of the film and rollers. Further research identified two main causes of the deviation. One is the change in the effective friction coefficient due to the load dependency of rubber, resulting in a significant difference in the friction coefficient under high tension compared to the initial input parameters. Another cause is the substantial change in Young's modulus between the rolled copper foil and PET film, with the plasticity range of the copper foil exceeding the original formula's predicted range. To overcome these issues, this study modeled the contact surface between copper foil and rubber roller and analyzed the changes in the friction coefficient. Subsequently, data analysis was conducted using the mathematical software Matlab, and auxiliary coefficients were introduced to correct the irrational data after the material change of the film,thereby enabling more accurate prediction of defect occurrence during the transport of films made of different materials.

We have prepared organic conducting nanocomposites of polypyrrole in the conductive portion, and indium tin oxide (ITO) or zirconia (ZrO₂) nanoparticles as dispersants. The polypyrrole-inorganic oxide nanoink successfully achieved stable colloidal dispersion of polypyrrole in water, which usually aggregate in aqueous liquids. The polypyrrole-ITO nanocomposites exhibited up to a conductivity of 15 S/cm, while that of the polypyrrole-ZrO₂ was 2.3 S/cm. Applying the polypyrrole-inorganic oxide to an olfactory receptor chip, we measured the resistance during ammonia injection as an odorant, in order to explore its potential as an olfactory sensor.

This paper presents Optical Coherence Stressgraphy (OCSE) based on PS-OCT, which can obtain stress tomography from low coherence interference fringe patterns caused by photo-elastic effect at a cross-section. OCSE can visualize the difference between the secondary principal stress as fringe patterns by photo-elastic effect using PS-OCT. The stress distribution can be obtained by finding the spatial frequency of photo-elastic low-coherence interference fringes shown in the stokes parameter tomographic map S_a(x, z)/S₀(x, z) . In this experiment, OCSE was applied to laser welded material of PAR and PBT/PC alloy material. As a result, this system can offer the tomographic retardation map S3 which was verified to be depth-resolved and be dependent on the residual stress by laser welding. It was found that there is a correlation between the maximum stress by OCSE and the number of chemical cracks. Consequently, it was suggested that the proposed OCSE can visualize non-destructively and micro-tomographically the residual stress even for nontransparent.

We have developed a method to visualize micro-defects on curved surfaces using an imaging system to obtain a color mapping of light directions reflected from the surfaces. Furthermore, we constructed an image processing algorithm for automatic detection of these micro-defects. In this paper, it is shown that the method has the capability to automatically detect micro-defects on curved surfaces with depths ranging from 0.1 μm to several tens of μm.

Many of the public infrastructure facilities currently in use were constructed during the period of high economic growth and are rapidly becoming obsolete. On the other hand, the number of workers who inspect these infrastructure facilities has been decreasing in recent years. In particular, inspection work on underground infrastructure uses hand-held underground radars that are manually pushed to take measurements, which requires a great deal of labor and time. Therefore, the introduction of autonomous mobile robots is required from the perspective of improving inspection work efficiency and saving labor. High self-position estimation accuracy is required for autonomous movement and for identifying the location by comparing the coordinates of underground objects with information from underground radar. In this study, we adopted visual odometry using road surface video images as a self-localization method, and constructed and evaluated an outdoor experimental system to verify self-localization outdoors.

In recent years, automated machine learning (AutoML) has been developed with democratizing machine learning. AutoML tools can generate classifiers and prediction equations with a few clicks by simply collecting data and setting up the desired problem, and their use is expanding. On the other hand, classifiers and prediction formulas generated by AutoML are not necessarily easy to implement in edge devices such as IoT sensors. In this study, we implement several machine learning models generated by AutoML on IoT sensors and discuss how to realize the problem of identifying anomalies in the machine structure. We focused on a simplified discrimination method of deterioration of a water pipe and its implementation with an IoT sensor module by machine learning. We used DataRobot, an AutoML platform, to generate 66 models to determine the deterioration of water pipes. Furthermore, we considered the discrimination accuracy of models based on decision boundary of machine learning algorithms. The results show that the logistic regression has best accuracy, followed by the decision tree algorithms which have good accuracy.

Owing to aging of distribution water main, the accident such as leakage and explosion are occurring. To prevent above accidents, it is important to quantify the condition of water main by Non-Destructive Testing (NDT) and reflect it in renewal and repair plans. One of method to maintain the main efficiently, deterioration diagnosis method for distribution water main using the eigen frequency of in-plane bending mode in circular cylindrical shell is already suggested. The eigen frequency of in-plane bending mode is expected to have high accuracy in detection of deterioration, because the eigen frequency is proportional to pipe thickness. In actually water main is subjected to ground soil elastic force and water pressure in the inter-outer edge. However, in previous study, the effects of the edge boundary conditions were not considered. Thus, we focused on the annular disk model. The annular disk model is expected to expansion for modeling of the edge boundary condition. In this paper, the fundamental consideration of eigen frequency analysis of in-plane bending mode was conducted using annular disk model.

HDD vibration problem is important for equipment quietness, failure prevention, heat trouble, and so on. Owing to the vibration suppression, the dynamic absorber was well used technology. In this paper, the dynamic absorber for HDD housing vibration was proposed based on the model of harmonic oscillator heat bath. At first, the design problem of dynamic absorber was defined for harmonic oscillator heat bath noise. Furthermore, the numerical calculation was conducted. As the result, to exist of dynamic absorber was revealed because of mean square value of main system in case of with dynamic absorber was decreased than the case of no absorber. Moreover, the minimum mean square value was dramatically changed by mass ratio. Especially, the minimum mean square value was depended on the ratio of angular frequency between dynamic absorber and harmonic oscillator heat bath. Finally, the consideration of operational principle of proposed dynamic absorber was conducted.

The occurrence of resonance between electrodes has been mathematically proven using a wave equivalent circuit. Conventionally, resonance phenomena have been observed only in piezoelectric materials, but they are determined not as a property of piezoelectric materials, but as the properties of elastic wave waves. In general, two electrodes with air in between them show infinite resistance, and no current flows. It is understood that the electrical characteristics between the electrodes where the resonance phenomenon is occurring with respect to electromagnetic waves also produce resonance characteristics. It was explained that resonance characteristics can be obtained for electromagnetic waves as well as for crystal oscillators of elastic waves. For the generation of modes, the basic process was calculated in detail assuming a reflector. The resonance characteristics between electrodes were also explained. As a result, various wave devices can be considered based on the resonance phenomenon between electrodes. Energy is concentrated. Large Q value, A resonator with a high frequency, an antenna that combines a magnetic field induced by an electric current at the resonance point and an electric field induced by proximity, a magnetic field induced from a large current at the resonance point, and an electromagnetic force generated from the current. There is a possibility of realizing a linear motor in a simple system.

Capsule endoscopes are often used for medical examinations of the digestive system. Currently, endoscopy examination takes a few days to be completed because capsules do not have any actuator. Thus, studies have been conducted to address this issue, particularly focusing on impulse-driven and vibration-driven actuators. In this study, an inclined plate-legs actuator inspired by Setaria viridis was developed. The actuator can be driven by external vibration utilizing friction anisomorphism of inclined plate-legs. Small-sized inclined plate-legs actuator were designed and fabricated, considering as parameters the angles (45°, 60°, and 75°) and lengths (4 mm, 6 mm, and 8 mm) of the plate-legs; their friction anisomorphism was evaluated and the corresponding mechanisms were considered. Moreover, the running velocities of the actuators were measured when vibrations with different frequencies and amplitudes were applied. The experimental results confirmed that the actuators run with different mechanisms between lower and higher frequencies. At lower frequencies (< 40 Hz), the velocity increased with an increase in the vibration frequency. At frequencies (> 40 Hz), the actuator velocities exceeded the target speed of >10 mm/s. Therefore, the proposed design of vibration-driven actuator has potential to be applied in capsule endoscopes.

Micro manipulation technologies have been studied for manipulating objects that human cannot operate directly. In the micro manipulation, the operator should be skilled because the only information from the environment is image and the human cannot feel force from the object. Therefore, force feedback is required in order to improve operationality and safety. In this study, we developed a prototype of micro manipulator with long end effector which can be moved in the narrow space such as under objective lens of microscopes. We adopted electrical motor and implemented micro-macro bilateral control which can transfer enlarged/reduced position and force between human operator and micro manipulator. We confirmed that the micro-macro bilateral control was achieved and the developed manipulator can grasp 1.6 mm diameter screw with human operation. We also showed that intuitive operation was difficult because nonlinear disturbance such as friction or cogging torque was estimated as external force even though the manipulator did not contact to any object. These disturbance was enlarged and presented to the operator.

In order for a work robot to immediately start working after positioning and stopping, it is necessary to suppress free vibrations that occur when the robot stops. In the case of 1-degree-of-freedom vibration of a constant coefficient system, free vibration can be suppressed using the input shaping method in which the duration of the excitation force during acceleration and deceleration is a multiple of the natural period. However, in the case of a robot that turns while changing its posture, the moment of inertia is a function of time, so there is a problem that the period is not constant. Therefore, we express the moment of inertia as a function of time and derive a theoretical impulse response by applying the Sturm-Liouville type differential equation solving method.

This paper describes a method to reduce the transmitted force to electronic equipment mounted in the cabin of a construction machinery using a voice coil motor and capacitors. A construction machinery is usually operated on uneven surfaces, and the unevenness of the road surface causes impact vibrations in the cabin. This free vibration of the cabin induces transmission forces to the equipment mounted in the cabin. Because the transmitted force can cause electronic equipments to fail, the transmitted force should be reduced to protect it. Therefore, we propose a method to reduce the transmitted force using an electromagnetic damper consisting of a voice coil motor and a capacitor. Before the impact is applied to the cabin, electric charge is stored in the capacitor. When the cabin is impacted, an electromagnetic force is generated by passing an electric current from the capacitor to the voice coil motor. Because the waveform of the transmitted force is determined by the natural frequency and damping ratio of the cabin, the optimum capacitance and resistance were derived considering the natural frequency and damping ratio of the cabin, respectively. The effectiveness of the proposed method was verified through simulations and experiments.