THE KINETIC ANALYSIS OF THE TAEKWONDO AXE KICK

The purpose of this study was to analyze the kinetics of taekwondo axe kick. Twenty junior high school level taekwondo athletes served as subjects, and their mean age, height, weight and training experience were 17.1 ± 1 years, 168.8 ± 5.8 cm, 59.9 ± 6.7 kg and 5.8 ± 1.6 years respectively. Two Kistler force plates and multifunctional record instruments were used to measure kinetic parameters in each phase of the axe-kick motion. The conclusions described as following: 1. the time to peak anterior-posterior ground reaction force of kicking leg prior to the time to peak vertical force. 2.the peak vertical ground reaction force and impulse of support leg were 1.79 times of body weight and 88.1 N-s during leg-lift phase, and 0.86 times of body weight and 64.9 N-s during legaxe phase. 3. It’s suggested that during the training should emphasize to decrease the response time in order to reduce the total time

THE DYNAMIC ANALYSIS OF THE APPLIED FORCE ON JAVELIN DURING FINAL THRUST BY AN ELITE JAVELIN THROWER

According to the javelin rules, a throw is valid only if the tip strikes the ground before any other part of the javelin. So it is important to precisely control the applied force on javelin for further distance and tip-first landing. Two synchronized Redlake high-speed cameras (250 Hz) were used to videotape an elite thrower; a javelin with three fixed non-collinear markers was used in experiment. The aerodynamics and Newton-Euler equation were taken into account in the 3D inverse dynamic analysis. The results showed that the force was mainly on the axial direction as the whole hand gripped the javelin. However, as the portion of hand touching the javelin became lesser, the direction of force was changed from axial to lateral direction. The lateral torque was significantly larger than axial torque during the whole phase, and their maxima were 24.08 and 1.31 Nm, respectively. The results measured by this method were similar to those by force sensor, and it could be suitable for use in further researches

THE BIOMECHANICALANALYSIS OF TAEKWONDO AXE-KICK IN SENIOR HIGH SCHOOL ATHLETIC

The purpose of this study was to investigate the biomechanical factors of the Taekwondo axe-kick and compare the differences between male and female athletes for timing kinematicsand kinetics. The data gained from 23 test subjects of the Taekwondo team from the junior high school (male:16, female:?). Base on the results and discussion of the study, we have reached the following conclusion: the average movement speed has significant difference between male and female groups. The average movement speed has significant positive correlation with the peak vertical ground reaction force (body weight), the peak front-rear ground reaction and impulse at the kicking leg. While the kicking leg attacked the target, the higher point of the kicking leg and the larger power at the peak tront-rear ground reaction force, the faster attacking velocity(the resultant of toe velocity) at the target

An Investigation on Gender and the Effects on Behavior in Early Childhood Classrooms

Researchers who have studied children behavior in early childhood classrooms have found that classrooms are the first place where children learn about acceptable behavior and societal norms. Gender and behavior have been studied on children of later ages, i.e.; elementary, middle, high school, and higher education, but little has been researched regarding children of younger ages. Researchers of this study used quantitative methods to investigate, gender and the effects on children behavior in early childhood classrooms? The researchers recruited a total of 105 preschoolers from seven different classrooms in the Southwest Central region in the United States, to investigate, if there were any significant differences in preschoolers’ behaviors when compared to their genders. Research findings showed that boys demonstrated higher aggressive and hyperactive distractible behaviors than girls, which adds to an emergent body of research on gender and its effects on behavior during early childhood

THE BIOMECHANICAL ANALYSIS OF THE TAEKWONDO FRONT-LEG AXE-KICK

The purpose of the study was to analyze the biomechanics of taekwondo front-leg axekick. One force plates, two synchronized high-speed cameras were used to measure biomechanical parameters in each phase of the front-leg axe-kick. The results included: 1. The average reaction time and movement time were 0.423 sand 0.327 s, which respectively occupied about 56% and 44% of attack time. 2. The maximum velocity of hip, knee and ankle were 1.74 m/s, 5.25 m/s and 7.43 m/s respectively. When the kicking leg touched the target, the velocity of knee and ankle were 0.78m/s, 1.72m1s, and 4.64m1s respectively. 3. The peak vertical GRF and impulse were 0.96 SW and 77.57N-s. For decreasing the movement time, it's suggested that an athlete should increase the power and flexibility of lower extremities during the training section

Epidemiological Assessment of Risk Factors Associated with Bovine Ephemeral Fever Virus Exposure among Sheep and Goats in South Korea

Background: Bovine ephemeral fever virus (BEFV) is an arthropod-borne virus classified as a type species of the genus Ephemerovirus, family Rhabdoviridae. BEFV is the causative agent of bovine ephemeral fever (BEF), a non-contagious disease of acute febrile clinical signs in cattle and water buffalo. Some species might act as reservoir hosts, and antibodies to BEFV have also been found in asymptomatic sheep, goats, pigs, and many wild animals. This study aimed to conduct a retrospective cross-sectional serological screening in South Korea to address BEFV seroprevalence and identify risk factors for becoming seropositive for the virus in sheep and goats. Materials, Methods & Results: The apparent prevalence rates were considered to be the animal-level prevalence, defined as the proportion of serum neutralization test (SNT)-positive animals out of the total number of animals tested in the study area, and flock prevalence was defined as the proportion of SNT-positive flocks out of the total number of tested flocks in the area. A flock was classified as positive if at least one animal was SNT-positive. At the national level in 2011, 28 of 177 flocks (15.8%; 95% CI, 11.2−21.9%) and 71 of 498 heads (14.3%, 95% CI: 11.5-17.6%) that were analyzed showed serum neutralizing antibodies against BEFV. Our results revealed that age class, vector control, and geographic location affected seroprevalence to differing extents. In the univariate analysis, older age was a significant risk factor (OR, 2.327; 95% CI, 1.147-4.721; P = 0.017 in adults). The management risk factor attributes showed that preventive measures, such as routine application of insecticides in farms, decreased the odds of seropositivity for BEFV (OR, 0.514; 95% CI, 0.267-0.991; P = 0.044). Vector control was a significant protective factor, while animal species, flock size, and flock structure were not significantly associated. Differences in seroprevalence between variations in the presence of ruminant farms, lakes, or rice paddies within a 1-km radius or type of land use were not statistically significant (P > 0.05). We observed a significant difference in the individual likelihood of being positive in the southern provinces with respect to that in the northern provinces (OR, 2.166; 95% CI, 1.228-3.824; P = 0.007). Differences in seroprevalence between variations in the eastern and western regions were not statistically significant (P > 0.05). The retrospective study results showed that the virus was widely distributed in sheep and goats in South Korea, with seropositive rates ranging from 7.8% to 19.7% between 2003 and 2008.Discussion: This is the first report of circulating antibodies against BEFV in sheep and goats in South Korea. The serological prevalence of BEFV infection in sheep and goats was significantly different between different age cohorts, vector control, and geographical locations: it was higher in the older group and the southern and western regions of South Korea. Determination of seropositivity rates often leads to an understanding of virus circulation dynamics and is useful in the formulation of disease control measures. Our results demonstrated that vector control was a significant protective factor; therefore, the summer control of vectors could be better implemented in provinces with elevated seropositivity rates. The results of this seroprevalence study may serve as a basis for future epidemiological studies on BEFV infection in South Korea

Greater Privacy Protection for Online Credit Card Payment

Privacy is always one of the primary concerns in electronic commerce. Consumers must have the right to keep their buying habits and personal information confidential, especially when it comes to on-line credit card payment. Not just only because this payment method has been becoming the trend of modern consuming practice, but also it involves the sensitivity of privacy information. Based on the need-to-know principle, transaction information should be distributed properly among participants to be against aggregation and analysis. In this paper, the privacy required for on-line credit card payment is described, and the privacy protection on three common payment protocols such as SSL, SET and 3D SET are also analyzed in detail. Two solutions are then proposed to enhance privacy protection for cardholder

THE CALCULATION ON THE ROTATIONAL KINEMATICS ABOUT THE LONGITUDINAL AXIS OF JAVELIN BY THREE METHODS

The motion of javelin is complicated after it is released. Itis necessary to use some skills to calculate the rotation kinematics about the longitudinal axis of javelin. In this study, the Euler angle, the Cardan angle and the screw axis methods were used to calculate these kinematic variables. Two synchronized Redlake high-speed cameras (250 Hz) and a javelin with three fixed reflective markers were used in the experiment. Generally the results by three methods were close, and all of the three methods are suitable for the calculation on these variables. In the Euler angle and Cardan angle methods, the order of rotation sequence needs to be taken account, however no similar problem occurred in screw method. The results suggested that the longitudinal axis should be set as second axis in either Euler angle or Cardan angle methods to avoid Gimbal Lock (singularity) problem

Queer Ecologies: A Final Syllabus/Zine Product of Our Independent Study

This zine is the product of our independent study course Queer Ecologies, which is an exploration of bio-social systems using a queer and feminist theoretical lens. We aim to look critically at knowledge formation and construct alternative visions for more just and sustainable relationships between science, nature, and ourselves. While queer theory most directly interrogates the normative structure of heterosexuality both in humans and in biology more broadly, these studies include analyses of hierarchy, power, and value. Queer Ecology can be used to examine phenomena such as climate change, extinction, pollution, species hierarchies, agricultural practices, resource extraction, and human population debates – all of which are deeply tied to cultural valuations of the natural world. We also examine the core questions and debates in the field pertaining to gender and environment, queer ecofeminism, and the development of environmentalism from global perspectives