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Copyright of Journal of the Society of Plant Engineers Japan is the property of Society of Plant Engineers Japan and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rigakuryoho Kagaku is the property of International Press Editing Center Incorporation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of the Society of Plant Engineers Japan is the property of Society of Plant Engineers Japan and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ethnoarchaeological research can elucidate the relationship between the body, objects, and technology and is expected to become increasingly important in future archaeology. This paper presents findings from continuous research on pottery production and individual potters in a pottery village in Thailand. A quantitative analysis of pottery sizes and shapes and motion analysis of the potters were conducted. The results show that skilled potters maintain stable movements in the long term. This indicates one aspect of the nature of motor habits, which were developed through long-term repetitive training. The findings also reveal the acquisition process of motor habits, social and individual learning in pottery making, unintentional mutual imitation, and interaction between humans and tools. These results are based on archaeological and anthropological perspectives; however, the findings are also relevant to the field of psychology. [ABSTRACT FROM AUTHOR]

Methane hydrate is expected as domestic energy resources in near future in Japan. Especially the shallow-type methane hydrate and the associated methane plume are regarded as sustainable energy resources. In this paper, the investigation of the methane hydrate particle motion in the methane is presented. A quantitative analysis of the motions of the ascending methane hydrate particles seeping from the seafloor and reproduced by the numerical simulation is performed by the two-dimensional motion analysis technique and the behavior is discussed in detail. [ABSTRACT FROM AUTHOR]

The purpose of this study was to clarify the effect of continuous dribbling training on the dribbling movement mode and game performance of junior youth soccer players. The subjects were 32 junior high school soccer players: 17 in the training group, and 15 in the control group. Both groups did 2 hours of training 3 times a week for 16 months. The training group performed dribbling training while the control group performed agility and pass & control training for the first 40 minutes. The dribbling tests, motion filming and 11 vs 11 games with the third group were carried out before each group's training, after 3 months, 6 months, 10 months, and 16 months. The results showed that time in the dribbling test was decreased to a greater degree in the training group than in the control group. With zigzag dribbling, time showed a greater decrease only in the training group as training progressed. For double scissors feinting, the time in double scissors showed a greater decrease in the training group than in the control group. This was because the standard deviation of body axis inclination decreased in a crosswise direction in the YZ plane in the training group. Furthermore, the center of gravity velocity at ball carrying showed a significant increase only in the training group as training progressed. This was because the knee joint angle of the supporting leg decreased at the moment of ball touch, and the knee joint angular velocity of the supporting leg increased upon lifting from the ground in the training group. With double touch feinting, the ball velocity and center of gravity velocity showed greater increase in the training group than in the control group. This was because the knee joint angle of the supporting leg decreased at the moment of ball touch, and the knee joint angular velocity of the supporting leg increased upon lifting from the ground in the training group. With regard to game performance, the success rate in dribbling was significantly improved only in the training group. The success rate in passing showed a decrease in both groups after 3 months, but was significantly increased only in the training group. Consequently, this study clarified that continuous dribbling training intended for junior high school soccer players decreased the time in the dribbling test and changed the dribbling movement mode, thus improving dribbling skill. It is suggested that this improvement will contribute to enhancement of game performance in terms of dribbling and passing. [ABSTRACT FROM AUTHOR]

This study attempted to clarify the factors responsible for the change in hand propulsive force when stroke frequency was changed in the crawl. Eight male swimmers performed five 20-m front crawls. The first trial involved maximal effort, and then the stroke frequency was controlled during the next 4 trials. The instructed stroke frequencies were 70%, 80%, 90%, and 100% of the stroke frequency in the maximal effort trial. To calculate the hand resultant force, the pressure acting on the palm and the dorsum of the hand were measured, and the product of the pressure difference and the hand plane area was defined as the hand resultant force. Since the hand propulsive force is the propulsion component of the hand resultant force, its value was calculated from the normal vector of the hand plane and its unit vector by three-dimensional motion analysis. Additionally, the propulsion ratio was calculated to show how effectively the hand resultant force acted as the hand propulsive force. These variables were compared with the average for 1 stroke cycle and each movement phase, respectively (glide, pull, and push). The results indicated that as the stroke frequency increased, the dorsum pressure value increased significantly to negative (η2 = 0.82, p <0.001). Also, an increase in the pressure difference between the palm and the dorsum resulted in an increase in the hand resultant force. In the push phase, the increase in the hand resultant force was directly related to the increase in the hand propulsive force. In the glide phase, not only the fluid force, but also the propulsion ratio increased. This was assumed to be because the ratio of the dorsal plane to the propulsion direction was increased while the hand was moving in a vertical direction and a lateral direction in addition to a forward direction. This was considered to allow the fluid force to act more effectively in the propulsive direction, leading to an increase in the hand propulsive force. [ABSTRACT FROM AUTHOR]

In recent years, the demand for fine particle materials has been increasing in various industrial fields such as electronics, chemistry, and medicine. Ball mills are commonly used for the production of fine particle materials, but they have some problems. In particular, when the rotation speed is increased, the contents stick to the inner wall of the container and rotate together. That is called the critical condition, and the efficiency is significantly reduced. The three-dimensional ball mill, which rotate its container with two degrees of freedom, is proposed as a solution to overcome such problems. We found that the critical condition is suppressed by using three-dimensional ball mills. It was also reported that both frictional heat generated during pulverization and particle unevenness are reduced. Although some advantages can be found with this machine, there is few theories that explain what has been happened. In this study, we focused on the mechanism of suppressing the critical condition. First, based on the past study for ordinary ball mills, we created a theoretical formula for three-dimensional ball mills in critical condition. Next, using the formula, we simulated the motion of three-dimensional ball mills. Finally, we compared the simulation with the motion of the actual machine, and confirmed that they agreed well.

Copyright of Journal of the Japan Research Association for Textile End-Uses / Sen'i Seihin Shohi Kagaku is the property of Japan Research Association for Textile End-Uses / Sen'i Seihin Shohi Kagaku and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper presents examination of a proposed method for center of gravity (COG) velocity estimation during walking using information obtained from lower limb motion measurements. Lower limb joints and muscles around these joints are used during walking. Gait velocity changes according to lower limb muscle activity. Some earlier reports of relevant studies have suggested that lower limb muscle weakness reduces the walking rate, which increases the probability of falling. Therefore, the relation between the COG velocity and lower limb motion during walking must be clarified. For this study, we constructed gait COG velocity models that represent the relation between the COG velocity and lower limb joint power for each gait phase. For this experiment, gait was measured using a 3D motion analysis system and floor reaction force gauges. We estimated the gait COG velocity models’ parameters by applying Kalman filtering using measurement information. The results of analyses using gait COG velocity models indicate a quantitative relation between the COG velocity and the lower limb joint power during walking. Furthermore, results demonstrated that the lower limb joint power that influences the COG movement differs in each gait phase. This analytical method is anticipated for use in the evaluation of healthy feet and ill feet and for evaluating the balance of left and right feet.

Copyright of Journal of the Japan Research Association for Textile End-Uses / Sen'i Seihin Shohi Kagaku is the property of Japan Research Association for Textile End-Uses / Sen'i Seihin Shohi Kagaku and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In a previous report, the author presented a motion analysis method for rigid multibody systems, called nullspace matrix method of differential equation type. The method determines the nullspace matrix by solving a differential equation with respect to the nullspace matrix, while many other methods which use the nullspace matrix determine it algebraically. Due to this the presented method can obtain the nullspace matrix for systems with redundant constraints or continue the computation when the systems pass through the singular configurations by using relatively large value of stabilization parameters. The presented method uses the QR decomposition whose computational cost is moderately high. In addition, when the system passes through the singular configurations, the accuracy and stability of the presented method decreases since the differential equation for the nullspace matrix becomes incomplete. This paper improves the method in the previous report in the aspects of the computational efficiency and treatment of the singular configurations. The validity of the improved method is verified by numerical examples.

Many women undergo lumbopelvic pain (LPP) during pregnancy. The main factors for LPP are the physical stress related with change of posture and muscle relaxing around pelvis. Also it is thought that movement patterns during daily activity are associated with LPP. Therefore, this paper attempts to investigate the characteristic of movement patterns that have affect LPP during pregnancy. For this purpose, an experiment was conducted to measure standing up and sitting down of pregnant women using inertial sensor unit (IMU), which is simple device and is able to measure motions such as vibration or rotation quantitatively. Then movement evaluation parameters were calculated from measured data of lumber angular velocity. As the movement evaluation parameters, Maximum peak, Minimum peak, Peak to peak (PP: Range between Maximum peak and Minimum peak), Time of PP, PP divided by Time of PP, Root mean square of each parameter, and each parameter divided by Body mass index variation (BMIV) were calculated during both of standing up and sitting down for each of roll, pitch, and yaw angles. Finally, we consider whether there is any relevance between LPP and movement characteristics by comparing the movement evaluation parameters of LPP group with these of non-LPP group. As a result, it appears that Maximum peak, PP and PP/Time of PP of pitch angle during standing up have some relevance to LPP. Additionally, particular features of LPP group in roll and yaw angles and during sitting down were founded by accounting for BMIV to the proposed parameters.

This paper presents a proposed method for center of gravity (COG) velocity estimation during squatting using information obtained from lower limb motion measurements. A squat exercise uses the lower limb joints and the muscles around these joints. The squat exercise velocity changes according to the lower limb muscle activity. Some earlier reports of relevant studies have suggested that muscle weakness and neurological deterioration influence the COG velocity when standing up. Therefore, it is important to clarify the relation between the COG velocity and lower limb motion for efficient training and the prevention of falls among older people. For this study, we constructed a squat velocity model that represents the relation between the COG velocity and lower limb joint power during squatting. Although no joint power indicates each muscle activity in detail, it is possible to estimate muscle activities around the joints approximately by using the joint power. For this experiment, the squat exercise was measured using a 3D motion analysis system. The experiment was conducted for three stance widths. The COG velocity and the lower limb joint powers were calculated using information from the 3D motion analysis system. We estimated the squat velocity model parameters by application of Kalman filter using the measurement information. The analysis results for the squat velocity model indicated a quantitative relation between the COG velocity and the lower limb joint power during squatting. Furthermore, comparable results were obtained from three stance widths. This analytical method is anticipated for use in evaluation of motor function and exercise assisting device design.

This paper presents a method for analysis of motion of multibody systems. In the presented method, the null space matrix for the constraint Jacobian is determined by solving differential equations, not by solving algebraic equations which is common in other methods such as the coordinate partitioning method and the null space method. In the algorithm, the QR decomposition for the constraint Jacobian is utilized. Use of the differential equations for the null space matrix and the QR decomposition as well as the introduction of stabilization terms allow us to analyze without any problems motion of multibody systems which have redundant constraint and/or singular configuration. In addition, the presented method solves the Maggi's equation which is the equation obtained by eliminating the Lagrange multipliers from the equation of motion and by expressing the unknown variables only with the independent components. Thus the computational cost is not so high. The validity of the presented method is verified by numerical examples.

Hemiplegic patients often have reduced typing speed due to finger paralysis. Our motivation is to develop a keyboard that enables their typing speed to increase. For this purpose, we have developed a three-dimensional keyboard that reduces the distance that fingers move while typing. In this paper, our objective was to construct the finger model that combines the motion speed and muscle fatigue for design of keyboard that can be typed with fast motion speed and low muscle fatigue. In experiment, we measured the finger position using a magnetic 3D motion device and EMG when the participant pressed the proposed key. The experiment was carried out in a variety of the finger postures. We qualified the motion speed and muscle fatigue at each joint angle. Then, we weighted and combined two of the objective functions. We found out the Pareto solution and get an effective keyboard design straight. In the future, we verify the typing speed and finger muscle fatigue during typing the three-dimensional keyboard that is designed based on our finger model.

Copyright of Rigakuryoho Kagaku is the property of International Press Editing Center Incorporation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rigakuryoho Kagaku is the property of International Press Editing Center Incorporation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Japanese Journal of Clinical Sports Medicine / Nihon Rinsho Supotsu is the property of Japanese Society of Clinical Sports Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Japanese Journal of Clinical Sports Medicine / Nihon Rinsho Supotsu is the property of Japanese Society of Clinical Sports Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To improve safety during automobile collisions, it is necessary to examine not only accident damage by the first collisions but also motion after the collision. However, it is difficult to specify the factor which affects the collision motion of the automobiles with various structures and mechanisms, though the theoretical and experimental analyses have been reported. In this study, in order to clarify factors which affect the automobile motion after side collisions, as the first step, the motion evaluation of the automobile subjected to side collision at front part was investigated by carrying out model collision tests, and fundamental theoretical analyses. Trajectory of automobile's center of gravity after the model collision test showed good agreement with the theoretical analysis result. In the future, influential factors are gradually considered in motion analysis by the fundamental theory and experimental approach by the model collision test used in this study, and the effect of their factors on the reconstruction of the collision accident is quantitatively clarified.

The objective of this study was to develop a motion analysis system to evaluate relations between the activation of the lower limb muscles, the pedal force and the movement of the lower limb during the pedaling motion. To confirm the effectiveness of the proposed analysis system, we analyzed the pedaling motion of nine cyclists to identify their pedaling skill. In the experiments, cyclists were instructed to perform their pedaling technique at two pedaling rates (80-90 rpm and 110-120 rpm). Surface electromyography (EMG) signals was recorded from tensor of latae (TFL), rectus femoris (RF), hamstrings (HAM) and gastrocnemius (GAS), and pedal force was measured by a power meter (Pioneer Corporation). Furthermore, the lower limb motion during the pedaling was measured using a 3D motion capture system to investigate the relations among measured data as mentioned above. The experimental results show that the proposed analysis system reveals the pedaling skill of cyclists and the relations between the EMG data, the pedal force and the movement during the pedaling motion. In this paper, firstly, the activation section of the lower limb muscles during the pedaling was determined quantitatively. Secondly, Tukey-Kramer test was conducted to determine whether there are significant differences (p < 0.05) between the pedaling effectiveness of the three groups (elite group, amateur group and beginner group). Finally, the pedaling skill of the cyclists was revealed based on the analysis results of the measurement experiments.

In recent years, development of the automated driving system is aggressively promoted for the purpose of reducing burden of drivers and for the enhanced safety. Transferring the intention of the driver to the automobile control, such as to stop on the way or to change destinations, is essential even if a direct control from the driver is no longer necessary. Therefore, an in-car interface to conduct intention of the driver promptly and accurately to the automobile control is needed. In this paper, we proposed an interface which recognizes the intended target of the driver using gestures and speech recognition. The speech recognition technology was previously developed. Hence, we developed an interface to recognize the direction in which the driver is pointing toward from the gesture. We hypothesize that we can estimate the direction in which the driver is pointing toward from the fingertip and eye position. Verification using three-dimensional motion analysis system showed that it is possible to recognize the direction of the object with a maximum error of 5.5° and an average error of 1.2°. After verifying the hypothesis, a position measurement device that integrates Leap Motion® and KINECT®, the non-contact sensor, was developed to recognize gestures of the driver in the automobiles. The maximum error of the angle recognition in accordance with the present device was 16.1°. However, the value of the error exists only in a certain interval. For this reason, by taking into account the movement of the eye position, and provide adequate tuning for each driver, proposed interface is sufficiently usable.

Soil behavior generated by a root-cutting blade moving under the ground of an automatic spinach harvester for spinach for eating raw is analyzed in this paper. It is difficult to harvest spinach for eating raw by using automatic harvester because stems and leaves of spinach are soft and easily bruised. Thus the harvester which can be widely used among farmers has not been developed. To overcome the difficulty, we have been developing the automatic spinach harvester which does not bruise spinach. A trajectory of a root-cutting blade is very important to achieve this automatic harvesting without bruising spinach because the motion of cutting the root of spinach is influenced by soil which the blade presses and moves in. In this paper, accordingly, some characteristics in the behavior of soil caused by the moving blade are clarified by using the distinct element method (DEM) to investigate the automatic harvesting. In conclusion two important characteristics, the velocity of the moving blade and the volume of soil in the passage field the blade moved, are pointed out and described.

Recently, in the human-centered design of the car seat, mutual interactive relationship based on structural dynamics of the human-machine system has been analyzed, and this technique is used to the methodology for the automobile design. However, these topics have been studied for only vibration measurement in a steady state and studies to analyze human body behavior in practical lateral-directional transient acceleration have not been performed yet. The purpose of this study is to simulate biomechanical body behavior of vehicle occupant in lateral-directional transient acceleration. The proposed experimental device has characteristics of low cost and simplicity of use. The used experimental device is composed of the carriage, the car seat, rubber band, cushion, motion capture system and mobile force plate. In this paper, the seated body behavior with lateral-directional acceleration is simulated. Moreover, each joint angle and each ground reaction moment through the experiments are calculated and quantitatively evaluated by using this experimental device and singular value decomposition. As results of the experiments, each movement pattern reflected by lateral-directional transient acceleration is obtained as the remarkable feature quantities because the influences of the characteristic lateral-directional behavior on the human body are shown. Finally, the effectiveness of the proposed measurement technique and method to analyze the biomechanical behavior of vehicle occupant during lateral-directional transient motion and its quantitative evaluation based on singular value decomposition are validated.

Numerical simulation for a hydraulic operation stabilizing system of gas circuit breaker (GCB) driven by a hydraulic operating mechanism is treated . Valve collision and hydraulic column separation, created in hydraulic fluid by the movement of valves, are simulated. Constrictions between main piston and latching mechanism which is used to control the movement of the piston is taken into consideration. Results of simulation agree well with the experiments on the characteristics of the movement of valves, piston and hydraulic pressure. It is confirmed that the hydraulic mechanism with a hydraulic operation stabilizing system is stably operated, not affected by hydraulic column separation. Dimension of return circuit and latching mechanism which constitute a hydraulic operation stabilizing system are investigated. The range of diameter of restrictors in the circuit and latch angle to optimize a hydraulic operation stabilizing system are shown.

Copyright of Rigakuryoho Kagaku is the property of International Press Editing Center Incorporation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rigakuryoho Kagaku is the property of International Press Editing Center Incorporation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rigakuryoho Kagaku is the property of International Press Editing Center Incorporation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rigakuryoho Kagaku is the property of International Press Editing Center Incorporation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rigakuryoho Kagaku is the property of International Press Editing Center Incorporation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Rigakuryoho Kagaku is the property of International Press Editing Center Incorporation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Purpose] In this study, human body movement when lifting loads of different weights was recorded, and the characteristics were investigated. [Subjects] The subjects were 13 healthy males. [Method] Human body movement when lifting loads was recorded using a three-dimensional motion analyzer. There were 3 types of load: no-load, 10 kg, and 15 kg. [Result] The vertical movement range of the physical center of gravity, the knee joint flexion angle, the hip flexion angle, the hip joint extension moment, and the ankle joint plantar flexion moment were significantly increased by lifting heavy loads. The acceleration of the physical center of gravity upward was significantly decreased when lifting heavy loads. There were no significant differences in the ankle joint dorsiflexion angle, the anteversion angle of the body trunk, the knee joint extension moment, and the velocity of the physical center of gravity among the different loads. [Conclusion] The knee joint flexion angle, the hip joint flexion angle, the hip joint extension moment, and the ankle joint plantar flexion moment increased in line with increasing load. [ABSTRACT FROM AUTHOR]

[Purpose] We measured the line of sight of novice physical therapists, and by analyzing their investigative ability of motion, we tried to develop a skill index. [Subjects and Method] The subjects were 12 fourthyear students of a vocational training school. We showed them a video of a shoulder being raised after surgery for rotator cuff tear, and measured the stopping points before and after disclosing the profile. We also asked them to describe the type of disorder, points for attention, changes in points for attention, and points for attention in motion analysis, and investigated the line of sight characteristics. [Results] One subject answered the disorder type correctly, and there were significant differences between before and after profile disclosure, in the numbers of stopping points at the shoulder joint, the scapula area, and the elbow region. All subjects responded that the shoulder joint and scapula area were points for attention, answers which were in agreement with the measurement results. After disclosure, we determined the stopping points of those who answered that their points for attention had changed, and the number of points had reduced. [Conclusion] We consider that by presenting novices with a simple task, we can focus their sight on the points necessary for analysis, making it possible for them to gather information. [ABSTRACT FROM AUTHOR]