COMPARISON OF ANGULAR KINEMATIC PATTERNS BETWEEN CARVING TURN AND SKIDDING TURN DURING ALPINE SKIING

The purpose of this study was to investigate the movement patterns between segments (lower spine, pelvis, thigh, shank) and ski using the relative angular displacement on anteroposterior and vertical axis. Fourteen alpine ski instructors were participated in this study. Eight inertial measurement units were used to measure kinematic variables. Each skier was asked to perform ten carving turns and ten skidding turns on the groomed 15°slope, respectively. On the vertical axis, relative angular displacement of lower spine-ski was significantly increased during carving turn, whereas relative angular displacement of shank-ski was significantly increased during skidding turn. On the anteroposterior axis, relative angular displacement of lower spine-ski, pelvis-ski and thigh-ski were significantly increased during carving turn

COORDINATIVE PATTERNS BETWEEN CARVING TURN AND SKIDDING TURN DURING ALPINE SKIING

The purpose of this study was to investigate the coordinative patterns between segments and ski using the continuous relative phase (CRP) on anteroposterior and vertical axis during carving and skidding turn. Fourteen alpine ski instructors were participated in this study. Eight inertial measurement units were used to collect segment kinematic data. Each skier was asked to perform ten carving turns and ten skidding turns on the groomed 15° slope, respectively. CRP angles between all segments and ski were significantly increased during carving turn on the vertical axis. On the other hand, CRP angles between all segments and ski were significantly increased during skidding turn on anteroposterior axis. Therefore, skiers should perform the anti-phase movements of the lower spine-ski, pelvis-ski, thigh-ski and shank-ski on the vertical axis during the carving turn and the in-phase movements of the lower spine-ski, pelvis-ski, thigh-ski and shank-ski on the anteroposterior axis during skidding turn

SPRINTING CHARACTERISTICS OF WOMEN’S 100 METER FINALS AT THE IAAF WORLD CHAMPIONSHOPS DAEGU 2011

This study analyzed the sprinting characteristics of the finalists during the women's 100 m event in the IAAF World Championships Daegu 2011 in order to provide important information to track and field coaches and athletes. Five high speed cameras (Casio, Japan) with a sampling frequency of 300 Hz were used to calculate the number of steps, step length, and stride frequency of the eight sprinters in the women’s final event. There was a tendency to show a better performance time with a high number of steps (p=0.13) and shorter stride length (p=0.14) among the eight sprinters. Furthermore, stride frequency and performance time were negatively correlated as a higher stride frequency had a positive impact on performance time (p=0.02). Based on the relationship between COM velocity and lower extremity joint angles, the 4 top ranked sprinters showed the different strategies to maintain a high COM velocity during the mid portion of the race

SUCCESSFUL FACTORS OF 540° DWIHURYEOCHAGI IN TAEKWONDO

The purpose of our study was to provide fundamental information about success factors of 540° Dwihuryeochagi in Taekwondo. Twenty Taekwondo athletes who participated in the 2012 Taekwondo Kyukpa Wang (breaking king) championship: ten successful athletes (S, age: 23.1±1.6 yrs, height: 171.0±3.5 cm, body mass: 66.4±7.1 kg) and ten failed athletes (F, age: 22.3±1.8 yrs, height: 172.1±5.4 cm, body mass: 64.4±4.2 kg) were selected. Three-dimensional motion analysis using a system of 3 video cameras with a sampling of 60 fields/s was performed during the competition of 540 ° Dwihuryeochagi. Based on the findings, it is concluded that success factors of 540° Dwihuryeochagi were horizontal velocity of COM during P1, vertical velocity of COM during P2, and the time, kick distance, velocity and angle of lower extremities of P3-P4

LOWER EXTREMITY KINEMATICS OF SKI MOTION ON HILLS

This research study aimed to collect thre- dimensional joint angles of the lower extremity during a basic ski motion in order to provide more quantitative teaching guide-lines for ski instructors. Eleven infrared cameras were placed to cover the capture volume of three different stopping movements (e.g. “Pflug Fahren”) on hills. Six ski instructors participated in the test. Three trials of each stop were selected for comparison. Based on the results, skiers tended to use the edge of the ski and maintain a wider “V” shape at the shortest stop distance (e.g. 2m) compared to the other stops. Also, each skier had to invert the foot with a less flexed and more abducted knee and hip position as the stopping distance was decreased. This information will be useful for the development of more objective teaching guide-lines for beginner skiers

THE ORIGINS OF THE EAST ASIAN INCONGRUITIES IN THE MADDISON PROJECT DATABASE

The income gaps between Korea and her two richer neighbors, Japan and Taiwan in 1935, estimated by the Maddison Project using the backward projection method from 1990, are significantly different from the results based on directly comparing the price levels of 1935. We explore the sources of error in the estimation of PPP using GDP deflators. We find that the errors from the conceptual differences between PPP and GDP deflators are not large or systematically biased; the majority of errors come from the inconsistency of the two data sets, and the selection of the benchmark year. We estimate the GDP per capita of East Asian countries without incongruities, using information from all benchmark years available

Graphene Oxide and Its Inorganic Composites: Fabrication and Electrorheological Response

Composite particles associated with graphene oxide (GO) and inorganic materials provide the synergistic properties of an appropriate electrical conductivity of GO with the good dielectric characteristics of inorganic materials, making them attractive candidates for electrorheological (ER) materials. This review paper focuses on the fabrication mechanisms of GO/inorganic composites and their ER response when suspended in a non-conducting medium, including steady shear flow curves, dynamic yield stress, On-Off tests, and dynamic oscillation analysis. Furthermore, the morphologies of these composites, dielectric properties, and sedimentation of the ER fluids are covered