Kinetic comparison of a side-foot soccer kick between experienced and inexperienced players     

Kawamoto R  Miyagi O  Ohashi J  Fukashiro S 《Sports biomechanics / International Society of Biomechanics in Sports》2007,6(2):187-198

The aim of this study was to identify critical kinetic variables that lead to increased ball velocity during a side-foot passing kick in soccer. Seven experienced male soccer players and eight inexperienced players participated in the experiment. They were instructed to perform side-foot kicks along the ground with maximum effort with an eye on the target line. The joint angles, angular velocities, and torques of the kicking leg were determined based on the three-dimensional kinematic data. The mean ball speed of the experienced group (21.4 +/- 1.5 m/s) was significantly faster than that of the inexperienced group (16.0 +/- 1.0m/s; P < 0.001). The motions of the inexperienced players tended to be less dynamic than those of the experienced players. The most noticeable difference in the kinetics of the kick was found in the hip flexion torque throughout the back-swing phase until the leg-cocking phase. The mean peak value of the experienced group (168 +/- 20 N x or m) was significantly greater than that of the inexperienced group (94 +/- 17 N x or m; P < 0.001). To increase ball speed during a side-foot passing kick, the generation of hip-flexion torque during the earlier stage of kicking is critical.  相似文献   

The national politics of educational advocacy in the context of global governance: international funding and support for civil society engagement in Cambodia     

D. Brent Edwards Jr.  Willian C. Brehm  Inga Storen 《Compare》2018,48(2):171-188

This paper examines the Civil Society Education Fund’s (CSEF) impact on the non-governmental organisation education partnership (NEP) in Cambodia. With financial backing from the World Bank and the Fast Track Initiative, the CSEF is an initiative that is managed internationally by the Global Campaign for Education. Its goal is to help national networks of non-governmental organizations participate in education decision-making and to serve as a watchdog for progress related to internationally agreed upon goals. Through the CSEF, the deployment of various strategies, and other external factors, the NEP was able to able to achieve recognition, legitimacy and influence at the national level. However, the NEP has had to balance working with the state and working for the state. This case study highlights strategies used by civil society actors to engage state actors, the efficacy of international support, and the conflicts inherent in both.  相似文献   

Acceleration patterns in the lower and upper trunk during running     

Masahiro Kawabata  Kenta Goto  Ken Sasaki  Eiji Hihara  Takahiro Mizushina 《Journal of sports sciences》2013,31(16):1841-1853

Abstract

The purpose of the present study was to relate 3D acceleration patterns of the lower and upper trunk during running to running gait cycle, assess the validity of stride duration estimated from acceleration patterns, investigate speed-dependent changes in acceleration, and examine the test–retest reliability of these parameters. Thirteen healthy young men performed two running trials each on a treadmill and on land at three speeds (slow, preferred, and fast). The 3D accelerations were measured at the L3 spinous process (lower trunk) and the ensiform process (upper trunk) and synchronised with digital video data. The amplitude and root mean square of acceleration and stride duration were calculated and then analysed by three-way analysis of variance to test effects of running conditions, device location, and running speed. Bland-Altman analysis was used to evaluate the test–retest reliability. Marked changes in acceleration were observed in relation to foot strike during running. Stride durations calculated from the vertical accelerations were nearly equal to those estimated from video data. There were significant speed effects on all parameters, and the low test–retest reliability was confirmed in the anterior–posterior acceleration during treadmill running and the anterior–posterior acceleration at slow speed during treadmill and overground running.  相似文献   

Physiological responses at the lactate-minimum-intensity with and without prior high-intensity exercise     

Alessandro Moura Zagatto  Johnny Padulo  Adelino Ramos Sanchez da Silva  Paulo de Tarso Guerrero Müller  Willian Eiji Miyagi  Claudio Alexandre Gobatto 《Journal of sports sciences》2016,34(21):2106-2113

  相似文献   

The role of social trust in reducing long-term truancy and forming human capital in Japan     

Eiji Yamamura 《Economics of Education Review》2011,30(2):380-389

This paper attempts to examine how social trust influences human capital formation using prefectural level data in Japan. To this end, I constructed a proxy for social trust, based on the Japanese General Social Surveys. After controlling for socioeconomic factors, I found that social trust plays an important role in reducing the rate of long-term truancy in primary and junior high school. Results suggest that social trust improves educational quality.  相似文献   

Optimal parameter estimation of ε-filter employing distribution distance     

Noriaki Suetake  Go Tanaka  Hayato Hashii  Eiji Uchino 《Journal of The Franklin Institute》2012,349(8):2570-2584

As the filter which can effectively remove the small amplitude noises on digital images, the $\epsilon \mathrm{-}\mathrm{filter}$ has been proposed. In order to effectively use this filter, a smoothing parameter $\epsilon \mathrm{-}\mathrm{filter}$ should be appropriately estimated before applying it. To address this problem, the authors proposed the parameter estimation method based on Hellinger distance (HD). In the method, HD between a residual signal and assumed noise distribution was evaluated, and a parameter $\epsilon$ of the $\epsilon \mathrm{-}\mathrm{filter}$ was estimated by finding the value giving minimum distance. However, the enough discussion on use of HD has not been made.In this paper, it is attempted to utilize not only the HD, but also various distribution distances in the parameter estimation, and their performances and characteristics are compared and analyzed experimentally. Furthermore, the parameter estimation method is extended to be applicable for the vector $\epsilon \mathrm{-}\mathrm{filter}$ for the color images. Consequently, through the experiments, it is shown that L1-norm or maximum norm is appropriate as the distribution distance used in the parameter estimation methods from the view points of the simplicity of the calculation and MSE performance in the filtering.  相似文献   

The effect of young children on their parents’ anime-viewing habits: evidence from Japanese microdata     

Eiji Yamamura 《Journal of Cultural Economics》2014,38(4):331-349

Anime is now considered an accepted form of animation and is considered to represent Japanese contemporary culture worldwide. There are many fans of anime and manga, creating a community known as otaku world. However, Japanese anime and manga have gained popularity in Western countries as well as in Japan. This paper attempts to ascertain the determinants of watching anime in Japan based on individual-level data from Japan. Despite the growth in the number of adult anime fans, children are still more likely to watch anime than adults are. Hence, this study investigates how adults are influenced by the presence of their children. After controlling for individual characteristics, it was found that people are more likely to watch anime when they have children aged less than 12 years who have not yet entered junior high school. Such an effect is larger for parents who belong to an older generation where people are less likely to prefer anime. This implies that the externality coming from children results in parents watching anime. The findings of this study show that externalities from surrounding people play a critical role in enlarging the market of modern cultural goods representing “Cool Japan.”  相似文献   

The role of water in Earth's mantle     

Eiji Ohtani 《国家科学评论(英文版)》2020,7(1):224

Geophysical observations suggest that the transition zone is wet locally. Continental and oceanic sediment components together with the basaltic and peridotitic components might be transported and accumulated in the transition zone. Low-velocity anomalies at the upper mantle–transition zone boundary might be caused by the existence of dense hydrous magmas. Water can be carried farther into the lower mantle by the slabs. The anomalous Q and shear wave regions locating at the uppermost part of the lower mantle could be caused by the existence of fluid or wet magmas in this region because of the water-solubility contrast between the minerals in the transition zone and those in the lower mantle. δ-H solid solution AlO₂H–MgSiO₄H₂ carries water into the lower mantle. Hydrogen-bond symmetrization exists in high-pressure hydrous phases and thus they are stable at the high pressures of the lower mantle. Thus, the δ-H solid solution in subducting slabs carries water farther into the bottom of the lower mantle. Pyrite FeO₂H_x is formed due to a reaction between the core and hydrated slabs. This phase could be a candidate for the anomalous regions at the core–mantle boundary.  相似文献   

Item Pool Maintenance in the Presence of Item Parameter Drift     

R. Darrell Bock  Eiji Murakl  Will Pfeiffenberger 《Journal of Educational Measurement》1988,25(4):275-285

Differential linear drift of item location parameters over a 10 -year period is demonstrated in data from the College Board Physics Achievement Test. The relative direction of drift is associated with the content of the items and reflects changing emphasis in the physics curricula of American secondary schools. No evidence of drift of discriminating power parameters was found. Statistical procedures for detecting, estimating, and accounting for item parameter drift in item pools for long-term testing programs are proposed  相似文献   

The sensitivity of the alternative maximal accumulated oxygen deficit method to discriminate training status     

Alessandro M. Zagatto  Fabio Y. Nakamura  Fabio Milioni  Willian E. Miyagi  Rodrigo A. B. de Poli  Johnny Padulo 《Journal of sports sciences》2017,35(24):2453-2460

The purpose of the study was to investigate the sensitivity of an alternative maximal accumulated oxygen deficit (MAOD_ALT) method to discriminate the “anaerobic” capacity while comparing: least trained (LT) participants (n = 12), moderately trained (MT) participants (n = 12), endurance trained (ET) participants (n = 16), and rugby (RG) players (n = 11). Participants underwent a graded exercise test on a treadmill and a supramaximal effort for assessing MAOD_ALT. MAOD_ALT was calculated as the sum of oxygen equivalents from the phosphagen and glycolytic metabolic pathways. MAOD_ALT was significantly higher (P < 0.05) in RG (64.4 ± 12.1 mL · kg^?1) than in ET (56.8 ± 5.4 mL · kg^?1; effect size [ES] = 0.77; +13.5%), MT (53.8 ± 5.3 mL · kg^?1; ES = 1.08; +19.8%), and LT (49.9 ± 4.5 mL · kg^?1; ES = 1.50; +36.4%). In addition, the magnitude-based inference analysis revealed that MAOD_ALT was likely (LT vs. MT), very likely (MT vs. RG, and ET vs. RG) and most likely (LT vs. ET, and LT vs. RG) different between all groups, except for MT and ET, which presented an unclear difference. In conclusion, MAOD_ALT was sensitive enough to distinguish the “anaerobic” capacity in individuals with different training status, especially for RG players compared with LT participants and MT participants.  相似文献