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1.
Tachibana K Yashiro K Miyazaki J Ikegami Y Higuchi M 《Sports biomechanics / International Society of Biomechanics in Sports》2007,6(1):44-58
Although it is clear that rowers have a large muscle mass, their distribution of muscle mass and which of the main motions in rowing mediates muscle hypertrophy in each body part are unclear. We examine the relationships between partial motion power in rowing and muscle cross-sectional area of the thigh, lower back, and upper arms. Sixty young rowers (39 males and 21 females) participated in the study. Joint positions and forces were measured by video cameras and rowing ergometer software, respectively. One-dimensional motion analysis was performed to calculate the power of leg drive, trunk swing, and arm pull motions. Muscle cross-sectional areas were measured using magnetic resonance imaging. Multiple regression analyses were carried out to determine the association of different muscle cross-sectional areas with partial motion power. The anterior thigh best explained the power demonstrated by leg drive (r2 = 0.508), the posterior thigh and lower back combined best explained the power demonstrated by the trunk swing (r2 = 0.493), and the elbow extensors best explained the power demonstrated by the arm pull (r2 = 0.195). Other correlations, such as arm muscles with leg drive power (r2 = 0.424) and anterior thigh with trunk swing power (r2 = 0.33 5), were also significant. All muscle cross-sectional areas were associated with rowing performance either through the production of power or by transmitting work. The results imply that rowing motion requires a well-balanced distribution of muscle mass throughout the body. 相似文献
2.
关联规则挖掘是解决电子商务推荐问题的重要方法之一.针对传统关联规则挖掘算法在解决移动电子商务环境个性化推荐问题时反复扫描数据库,频繁项挖掘效率低,关联规则挖掘准确率低以及规则大量冗余等不足,提出一个基于事务矩阵和用户兴趣度的关联规则挖掘算法(Matrix-and-Interestingness-based Association Rules Mining,MIbARM).该算法仅需扫描一次数据库,并在挖掘过程中不断缩小算法搜索空间以避免生成冗余候选项,同时避免了冗余规则挖掘,从而提高了挖掘效率.最后,在四组人工数据和160种参数组合的数值实验环境下,引入Apriori、CBAR 及BitTableFI算法对MIbARM进行对比验证.结果表明,在不减少有趣规则的前提下,MIbARM不但可有效避免冗余候选项集的产生,而且大幅减少了冗余规则数量,极大提高了算法的搜索效率,同时提升了个性化推荐的质量,更适用于移动电子商务环境下的个性化推荐问题. 相似文献
3.
Homma M Homma M 《Sports biomechanics / International Society of Biomechanics in Sports》2005,4(1):73-87
We investigated coaching points for the technique of the eggbeater kick in synchronized swimming. The movements of the eggbeater kick for six female synchronized swimmers, all the top-ranking members at the Olympics and World Championships, were analyzed by using three-dimensional motion analysis. By comparing the movements of higher eggbeater-skilled swimmers with lower eggbeater-skilled swimmers, the coaching points for techniques of the eggbeater kick in synchronized swimming are clarified as follows. First, to hold the knees as high and as near the water surface as possible and to keep the heels close to the hips. Secondly, to keep the knees as wide as possible. Thirdly, to kick sideways producing lift force, and not to kick downward. Fourthly, to pull up the heels to nearly the water surface at the out-kick, with strong internal rotation of the thighs. Lastly, to move the feet as if treading water, with strong dorsiflexion and plantar flexion and adduction of the foot; that is to move the feet like the motion of the hands when sculling. Moreover, the movements of higher eggbeater-skilled swimmers can be termed 'horizontal kick type' and the movements of lower eggbeater-skilled swimmers can be termed 'vertical kick type'. 相似文献
4.
Abstract The frequency of one-legged stance and two-legged stance differs considerably among sports. We therefore expect the balance ability of athletes from different sports to vary. This study compared the sway characteristics during a static one-legged stance of soccer players, basketball players, swimmers, and non-athletes. The centre of pressure sway during one-legged stance of ten male participants representing each of the four groups was measured using a stabilometer. Centre of pressure sway was assessed by four sway factors: sway velocity, anterior-posterior sway, horizontal sway, and high-frequency sway. None of the four groups of participants showed significant differences in body sway between standing on the dominant leg and standing on the non-dominant leg. The soccer players had more high-frequency sway and less anterior-posterior sway and horizontal sway than the basketball players, swimmers, and non-athletes. These results suggest that soccer players have superior ability to maintain a stable one-legged stance. Further study is required to determine how much of the superior balance ability in soccer players is innate and how much is developed through training, as well as to determine the relationship between balance ability and playing performance. 相似文献
5.
Two experimental tests of three-storied reinforced concrete structural walls having large openings were performed.Based on an original macro model,a multiple modified macro-model was proposed to develop a simple method to design a reinforced concrete structural wall with large openings and various opening locations.The interaction between reinforcement ties and concrete struts formed along the perimeter of openings was neglected in the original model.However,the strut-and-tie node was proposed to take account of such interaction in the proposed model.The predicted behavior of two specimens using such a proposed model was compared with the experimental results.It is shown that the behavior of structural walls with large openings could be modeled well using the proposed model.Moreover,the study indicates that the proposed model is applicable even in cases of multi-story structural walls having large openings and various opening locations. 相似文献
6.
Bilateral leg extension power and fat-free mass in young oarsmen 总被引：1，自引：0，他引：1
We evaluated the impact of bilateral leg extension power and fat-free mass on 2000 m rowing ergometer performance in 332 young oarsmen (age 21+/-2 years, height 1.76+/-0.05 m, body mass 62+/-6 kg; mean+/-s). The 2000 m rowing performance time was correlated with height (1.62-1.93 m; R2=0.23, P<0.001), body mass (53-95 kg; R2=0.53, P<0.001), fat-free mass (47-82 kg; R2=0.58, P<0.001) and bilateral leg extension power (1202-3302 W; R2=0.38, P<0.001). Multiple regression analysis selected fat-free mass and bilateral leg extension power as regressor variables. Fat-free mass explained 58% of the variability in rowing performance and the inclusion of bilateral leg extension power improved the power of prediction by 5%. The results suggest that rowing involves almost every muscle in the body and that bilateral leg extension power is very important during this activity. 相似文献
7.
This article reconsiders the relationship between transnationalism from above and from below, focusing on the consumer behavior of migrant workers. Although transnationalism from below may be regarded as positive resistance to dependence on nation-states and global capital, it also facilitates incorporation into global consumer cultures. This article reports how Bangladeshi return migrants have been enchanted by consumer practices in industrialized countries and have transmitted them into Bangladesh. Return migrants bring consumption habits as well as savings and remittances from industrialized countries. Returnees consequently spread consumer culture to their homelands efficiently, promoting the penetration of global capital and further migration. 相似文献
8.
Takuro Higuchi 《Inter-Asia Cultural Studies》2013,14(3):467-475
Since Seattle 1999, plenty of summit protests around WTO, G8/20, IMF, WB, COP, and so on happened in each of the different summit sites in the last decade. Such incidents were amazingly accepted because of their mass actions and widespread networks of activists sustaining a series of mass actions. As some researchers argue, those of generating networks are based on horizontality and autonomy, and they have already prefigured a powerful model for (re)organizing society. However, on the other hand, some researchers also argue the major shortcomings. In theory, the ‘Global Activist Network’ has been constructed since Seattle, although in practice there has still been a serious spatial gap between the Western part of the world and the other side of the world. Actually, the global activist network has excluded Asia. However, in 2008, the G8 summit was held in Japan. This paper, thus, aims to show that the global activist network since Seattle, which was limited to Europe and North America, has expanded to involve Asia through the 2008 G8 summit in Japan. The 2000 G8 in Japan was right after the Seattle in 1999, yet, due to its single-issue and national character of the movements, globally expanding networks didn't reach Japan. However, movements around the 2003 anti-Iraq war brought in the autonomous character of the alter-globalization movement and referred to the legacy of autonomous activisms. During the 2008 G8, some autonomous activists in Japan took over the diversity of tactics and networks of activists inherited since PGA, DAN and ‘Dissent!’. 相似文献
9.
Chris Forlin Norimune Kawai Satoshi Higuchi 《International Journal of Inclusive Education》2013,17(3):314-331
Within a tradition of a dual regular and special education system in Japan, the Government is promoting education reform that encourages an inclusive approach to education. This research investigates whether teachers are being trained for successful inclusion in Japan by reviewing the perceptions of all pre-service teachers in one university regarding their readiness for becoming inclusive practitioners. A move towards an inclusive approach to education in Japan is being promoted through collaboration and support between teachers trained in regular and special education. Thus, different perceptions of pre-service teachers preparing to work either in elementary schools or in special schools are a particular focus of this research. Discussion considers the need for better teacher preparation due to the very low understandings of inclusion and Japanese pre-service teachers’ perceived lack of skills, knowledge, experience, or training for an inclusive approach. 相似文献
10.
Stroke phase discrimination in breaststroke swimming using a tri-axial acceleration sensor device 总被引：3，自引：1，他引：2
Yuji?OhgiEmail author Hiroshi?Ichikawa Masanobu?Homma Chikara?Miyaji 《Sports Engineering》2003,6(2):113-123
Our previous study has demonstrated that the swimmer’s wrist acceleration in the crawl stroke and the breaststroke had distinctive
characteristics between subjects (Ohgiet al. 2000). In addition, stroke phase discrimination could be achieved for the crawl stroke by using the swimmer’s wrist acceleration.
This study provides evidence that the swimmer’s tri-axial wrist acceleration could be used for stroke phase discrimination
in the breaststroke. Swimmers’ triaxial wrist accelerations were measured and their underwater stroke paths calculated. The
authors examined the characteristics of the wrist acceleration, such as a local maximum or minimum, with reference to the
swimmers’ stroke paths. As a result, it was suggested that the three phases of the breaststroke, the recovery, the insweep
and the outsweep, could be distinguished using thex-axis (ulnar-radial axis) and they-axis (distal-proximal axis) acceleration. This methodology allows us to identify which stroke phase would be changed in skill
training or over training, and the acceleration sensor device has the potential to become a precise stroke pedometer or stroke
monitoring tool in the near future. 相似文献