Introduction to the special issue on patent processing

The processing of intellectual property documents, such as patents, has been important to the industry, business, and law communities. Recently, the importance of patent processing has also been recognized in academic research communities, particularly by information retrieval and natural language processing researchers. In addition, large test collections that include patents have recently become available, to enable the systematic evaluation of methodologies from a scientific point of view. In the light of these activities, this special issue is intended to collect advanced research papers on patent processing. As an introduction to the special issue on patent processing, this paper surveys the relevant literature and outlines the papers selected for the special issue.     

Contribution of hand and foot force to take-off velocity for the kick-start in competitive swimming

This study examines the hand and foot reaction force recorded independently while performing the kick-start technique. Eleven male competitive swimmers performed three trials for the kick-start with maximum effort. Three force platforms (main block, backplate and handgrip) were used to measure reaction forces during starting motion. Force impulses from the hands, front foot and rearfoot were calculated via time integration. During the kick-start, the vertical impulse from the front foot was significantly higher than that from the rearfoot and the horizontal impulse from the rearfoot was significantly higher than that from the front foot. The force impulse from the front foot was dominant for generating vertical take-off velocity and the force impulse from the rearfoot was dominant for horizontal take-off velocity. The kick-start’s shorter block time in comparison to prior measurements of the grab start was explained by the development of horizontal reaction force from the hands and the rearfoot at the beginning of the starting motion.     

Active recovery effects on local oxygenation level during intensive cycling bouts

We hypothesised that the oxygen supply to the fatigued muscles is improved after the recovery with exercise caused by aerobic metabolism in the slow twitch fibres during the recovery period. Ten males performed a 30 s maximum cycling (1st Exercise), followed by a 20 min rest interval (Interval Rest) in which participants were either sitting (No Exercise) or low intensive cycling (Active). Then they again underwent a 30 s bout of maximum cycling (2nd Exercise). The total work of the 2nd Exercise was higher in Active compared to No Exercise (297 ± 14 vs 276 ± 23 J · kg(-1), P < 0.01). After Interval Rest, the muscle oxygenation level (P < 0.05) and blood lactate concentration (P < 0.05) were lower in Active compared to No Exercise. In Active, the total work was higher in the 2nd Exercise than the 1st Exercise (297 ± 14 vs 277 ± 23 J · kg(-1), P < 0.01), and muscle oxygenation levels during the 2nd Exercise were also higher at 10 (P < 0.05) and 15 (P < 0.01) s after the beginning of the exercise. It was suggested that active recovery exercise would manage to increase the muscle oxygenation level, and improve the performance during the 2nd Exercise accompanied with blood lactate control.     

Cell-enclosing gelatin-based microcapsule production for tissue engineering using a microfluidic flow-focusing system

Gelatin-based microcapsule production using a microfluidic system and the feasibility of the resultant microcapsules for constructing spherical tissues surrounded by heterogeneous cells were studied. The first cell-encapsulation and subsequent cell-enclosing microparticle encapsulation were achieved using a microfluidic flow-focusing droplet production system. A hollow-core structure of about 150 μm in diameter was developed by incubating the resultant microparticles at 37 °C, which induced thermal melting of the enclosed unmodified gelatin microparticles. Mammalian cells filled the hollow-cores after 4 days of incubation. A cell layer on the cell-enclosing microcapsules was developed by simply suspending the microcapsules in medium containing adherent fibroblast cells. This method may prove useful for the generation of gelatin microcapsules using a microfluidic system for formation of artificial tissue constructs.     

Kinetics of throwing arm joints and the trunk motion during an overarm distance throw by skilled Japanese elementary school boys

The purpose of this study was to investigate joint kinetics of the throwing arms and role of trunk motion in skilled elementary school boys during an overarm distance throw. Throwing motions of 42 boys from second, fourth, and sixth grade were videotaped with three high-speed cameras operating at 300 fps. Seven skilled boys from each grade were selected on the basis of throwing distance for three-dimensional kinetic analysis. Joint forces, torques, and torque powers of the throwing arm joints were calculated from reconstructed three-dimensional coordinate data smoothed at cut-off frequencies of 10.5–15 Hz and by the inverse dynamics method. Throwing distance and ball velocity significantly increased with school grade. The angular velocity of elbow extension before ball release increased with school grade, although no significant increase between the grades was observed in peak extension torque of elbow joint. The joint torque power of shoulder internal/external rotation tended to increase with school grade. When teaching the overarm throw, elementary school teachers should observe large backward twisting of trunk during the striding phase and should keep in mind that young children, such as second graders (age 8 years), will be unable to effectively utilise shoulder external/internal rotation during the throwing phase.     

Optofluidic tweezer on a chip

A novel method to realize an optical tweezer involving optofluidic operation in a microchannel is proposed. To manipulate the optical tweezer, light from an optical fiber is passed through both PDMS (polydimethylsiloxane)-air surface lenses and an optofluidic region, which is located in a control channel. Two liquids with different refractive indices (RIs) are introduced into the control channel to form two different flow patterns (i.e., laminar and segmented flows), depending on the liquid compositions, the channel geometry, and the flow rates. By altering the shapes of the interface of the two liquids in the optofluidic region, we can continuously or intermittently control the optical paths of the light. To demonstrate the functionality of the proposed method, optical tweezer operations on a chip are performed. Changing the flow pattern of two liquids with different RIs in the optofluidic region results in successful trapping of a 25 μm diameter microsphere and its displacement by 15 μm.     

Kinetic analysis of the lower limbs in baseball tee batting

The purpose of this study was to investigate effects of the ground reaction forces on the rotation of the body as a whole and on the joint torques of the lower limbs associated with trunk and pelvic rotation in baseball tee batting. A total of 22 male collegiate baseball players participated in this study. Three-dimensional coordinate data were acquired by a motion capture system (250 Hz), and ground reaction forces of both legs were measured with three force platforms (1,000 Hz). Kinetic data were used to calculate the moment about the vertical axis through the body’s centre of mass resulting from ground reaction forces, as well as to calculate the torque and mechanical work in the lower limb joints. The lateral/medial ground reaction force generated by both legs resulted in the large whole body moment about its vertical axis. The joint torques of flexion/extension of both hips, adduction of the stride hip and extension of the stride knee produced significantly larger mechanical work than did the other joint torques. To obtain high bat-head speed, the batter should push both legs in the lateral/medial direction by utilising both hips and stride knee torques so as to increase the whole body rotation.     

Joint torque and mechanical energy flow in the support legs of skilled race walkers

This study analyzed the joint torque and the mechanical energy flow in the support legs of skilled male race walkers. Twelve race walkers were videotaped using a high-speed camera at a frame rate of 250 Hz set perpendicular to the sagittal plane of motion; their ground reaction forces were measured with two force platforms. A two-dimensional, 14-segment, linked model was used to calculate the kinetics of the support leg joints. In the initial part of the support phase, the mechanical energy flowed into the thigh and shank by the torque of the large hip extensors and knee flexors. In the middle part, the mechanical energy generated by the torque of the large plantar flexors flowed to the foot and from the foot to the shank by the ankle joint force. The mechanical energy flow by the forward joint force of the support hip was significantly related to the walking speed in the final part of the support phase. Our findings suggest that race walkers in the final part of the support phase should exert the torque of the knee extensors and hip flexors to transfer the mechanical energy more effectively to the support thigh and shank.     

Resolution of low-velocity control in golf putting differentiates professionals from amateurs

It is difficult for humans to apply small amounts of force precisely during motor control. However, experts who have undergone extended training are thought to be able to control low-velocity movement with precision. We investigated the resolution of motor control in golf putting. A total of 10 professional and 10 high-level amateur golfers participated. Putting distances were 0.6–3.3 m, in increments of 0.3 m. We measured the impact velocity and the club-face angle at impact, and the acceleration profile of the downswing. The professionals showed significantly smaller coefficients of variation with respect to impact velocity and smaller root mean square errors in relation to acceleration profiles than did the amateurs. To examine the resolution of motor control for impact velocity, we investigated intra-participant differences in the impact velocity of the club head at two adjacent distances. We found that professionals had higher velocity precision when putting small distance intervals than did amateurs. That is, professionals had higher resolution of low-velocity control than did high-level amateurs. Our results suggest that outstanding performance at a task involves the ability to recognise small distinctions and to produce appropriate movements.