• Title/Summary/Keyword: SERVE

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The Kinematic Analysis of the Tennis Flat Serve Motion (테니스 플랫 서브 동작의 운동학적 분석)

  • Oh, Cheong-Hwan;Choi, Su-Nam;Nam, Taek-Gil
    • Korean Journal of Applied Biomechanics
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    • v.16 no.2
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    • pp.97-108
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    • 2006

  • C. H. OH, S. N. CHOI, T. G. NAM, The Kinematic Analysis of the Tennis Flat Serve Motion, Korean Jiurnal of Sports Biomechanics, Vol. 16, No. 2, pp. 97-108, 2006. By the comparison and the analysis of the different factors during the tennis flat serve motion such as the required time per section, the movement displacement of the racket, the velocity of the upper limbs joints, the physical center of gravity, and the angle and the angular velocity of the upper limbs joints between an ace player and a mediocre player, these following results were drawn. First, the experiment result of the total time required per section in a tennis flat serve motion showed that an ace player was faster than a mediocre player by 0.4 seconds. This result suggested that it was required to increase the speed of the racket head by a swift swing to perform an effective flat serve motion. Second, the experiment result of the movement displacement of the racket in the tennis flat serve motion showed that an ace player greatly moved toward the left side on an x-axis. But both an ace and a mediocre player were shown to be at the similar points on a y-axis at the moment of the impact of the racket. An ace player was also shown to be located at a higher position on a z-axis by 0.23m. Third, the velocity of the center of gravity of an ace player was faster in every phase than that of a mediocre player in a tennis flat serve motion. Fourth, the velocity of the upper limb joints of an ace player was faster in every phase than that of a mediocre player in a tennis flat serve motion. Fifth, the experiment result of the speed of the racket head in tennis flat serve motion showed that a mediocre player was faster than an ace player in the first phase, but the latter was faster than the former in the second, third, and the fourth phases. Sixth, at the moment of impact of a tennis flat serve, an ace player had greater flexion of the angle of the wrist joints by an 11.8 degree than a mediocre player. An ace player also had greater extension of the angle of the elbow joint and the shoulder joint respectively by a 5.2 degree and a 1.4 degree with a mediocre player. Seventh, an ace player had greater angular velocity of the upper limb joints and the hip joints than a mediocre player at the moment of the impact of tennis flat serve. Eighth, an ace player was shown to have a greater change of the forward and the backward inclination (or the anterior and posterior inclination) of the upper body

  • https://doi.org/10.5103/KJSB.2006.16.2.097 인용 PDF

Differences in EMG of Trunk and Lower Limb According to Attack Method and Phase During Volleyball

  • Jeong, Hwan Jong;Baek, Gwang Eon;Kim, Ki Hong
    • International Journal of Internet, Broadcasting and Communication
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    • v.13 no.1
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    • pp.143-151
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    • 2021

  • The purpose of our study is to confirm the trend of the muscle activity of the trunk and lower limb muscles by the attack method and phase during volleyball exercise. To achieve this purpose, spike serve and spike were conducted for 9 male middle school students, and at that time, it was divided into four phase, such as run jump, take off, impact, and follow, and the rectus abdominis, erector spine, and left rectus femoris, left biceps femoris, left anterior tibialis, left gastrocnemius midialis, right rectus femoris, right biceps femoris, right anterior tibialis, right gastrocnemius midialis, were examined. Spike serve and spike were each performed three times, and randomly cross-allocated to extract accurate data. We was no difference in all muscles according to the attack method, and the muscle activity of the rectus abdominis was highest in the impact phase and the muscle activity of the vertebral spine muscle was highest in the close-up phase. In addition, all of the measured left and right lower limb muscles showed the highest muscle activity between the assisted devices. As a result, We found out that regardless of the method of spike serve and spike, the lower limbs in the run-up phase for a high jump, the vertebrae in the take off phase, the preparation phase for hitting the ball strongly, and in the impact phase at the moment of hitting the ball. It can be seen that it exerts the greatest power in the rectus abdominis.

  • https://doi.org/10.7236/IJIBC.2021.13.1.143 인용 PDF KSCI

Kinematical Analysis of Service Motion by Stance Types in Tennis Serve (테니스 서브 스탠스 유형에 따른 서비스 동작의 운동학적 분석)

  • Kim, Sung-Sup;Kim, Eui-Hwan
    • Korean Journal of Applied Biomechanics
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    • v.18 no.1
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    • pp.147-158
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    • 2008

  • The purpose of this study was to analyze the kinematical variables involved in two types of service motion in tennis pinpoint and platform stance, to find the fastest serving method. Seven skilled high school tennis players participated, and the kinematics were recorded by the Vicon motion analysis system. For the gathering and analysis of the data workstation, bodybuilder and polygon were used. During the back swing for the pinpoint stance, as the back leg moves forward the COM and the racquet moves more, thus taking 0.04 seconds longer than the platform stance. The body of the subject takes a bow-shape as the subject's foot moves back and their hip moves forward. This movement enables the subject to create more power during the backswing to impact. It also increases the spread of the COM racquet and the serve speed is increase. As there is no forward movement of the foot during the backswing of the platform stance, the COM and the racquet move less and thus the time required is shorter than that for the pinpoint stance by 0.04seconds. Similarly, the time spent creating the power for the serve is shortened, the COM racquet is narrower and the speed is lessened. However, the advantage of this serve is that it increases the stability.

  • https://doi.org/10.5103/KJSB.2008.18.1.147 인용 PDF

College Students' Images of Nurses (대학생의 간호사에 대한 이미지)

  • Kim, Bok-Lang;Kim, Seon-Hee;Kim, Ok-Sook;Nam, Young-Hwa;Lee, Kil-Ja;Chung, Bok-Yae
    • The Korean Nurse
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    • v.35 no.4
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    • pp.75-91
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    • 1996

  • The purpose of this study was to identify the college students' images of Nurses. Data were collected by open-ended questionnaire. 326 subjects were composed of nursing students and non nursing students who attended in universities and junior colleges at Pusan, Kyung-buk, and Chung-buk from April 30 to May 31, 1995. Collected data were analyzed by all researchers. Statements were categorized and endowed with Key meaning. The results were 1. Positive images of nurses were classified into 21 categories. They were , , , , , , , , , , , , , , , , , , , . 2. Among the positive images categories, statements about the were the most. Statements about , , , were a lot. 3. For nusing students, statements about the were the most. Statements about , , , were a lot 4. For non-nursing students statements about the were the most. Statements about , , , were a lot. 5. For nursing students who have no experience of the clinical practice statements about , , were a lot. 6. For nursing students who have not experience of the clinical practice, statements about , , were a lot. 7. Negative images of nurses were classified into 21 categories. They were , , , , , , , , , , , , , , , , , , , . 8. Among the negative image categories, statements about the were the most. satements about , , , , were a lot.

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An Analysis of Shoulder Joint Torque and Muscle Pattern Duing Tennis Serve by Isokinetic Motions on Isomed 2000 (Isomed 2000을 이용한 고등학교 테니스 선수 서브동작의 어깨관절 회전력과 근동원 양상 분석)

  • Kim, Sung-Sup;Kim, Eui-Hwan;Sung, Young-Ho;Kim, Tae-Whan;Chung, Jae-Wook
    • Korean Journal of Applied Biomechanics
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    • v.17 no.1
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    • pp.61-68
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    • 2007

  • The purpose of this study was to analyze the shoulder joint torque and muscle pattern performing as Tennis serve by Isokinetic motions on Isomed 2000. The subject, who was 5 males Korean national high school tennis players. By analyzing the flexion/extension of the shoulder, the peak torque of the internal/external rotation motion(at 60,180 and 300 degree/sec) at peak torque degree, the weight, peak torque, and power. combined with the timing of the electrode of the attached trapezius and posterior deltoid at the three part. From the data analysis & discussion the following conclusions were drawn. When doing a shoulder extension, the peak torque can be widely seen at 60degree per second. However the degree may be different depending on angular velocity. When doing an internal rotation at 90degree abduction, peak torque per weight was seen at 60degree per second. The degree of peak torque was at 31.6-44.2 and peak power was faster when angular velocity was increased. The aspect of muscle pattern was seen more at the internal rotation in the 90degree abduction rather than the shoulder extension. However the angular velocity was not influenced by muscle mobilization(in order of anterior deltoid, posterior deltoid and trapezius. To properly apply the above conclusion, when tennis players serve it is better the elbow be impacted by the extension. when doing isokinetic motion it is better to increase angular velocity and improve muscle power. also the anterior deltoid amongst the shoulder muscle should be improved to develop serve speed.

  • https://doi.org/10.5103/KJSB.2007.17.1.061 인용 PDF

Effect of Nitrification Inhibition on Soil Phosphate Release and Nutrient Absorption and Growth of Rice Plant (질산화작용 억제 처리가 논토양의 인산 가용화와 벼의 양분흡수 및 생육에 미치는 영향)

  • Chung, Jong-Bae;Kim, Byoung-Ho
    • Korean Journal of Environmental Agriculture
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    • v.29 no.4
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    • pp.336-342
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    • 2010

  • In a pot experiment, we studied the effect of nitrification inhibition on Fe reduction and P release in paddy soil and growth and nutrient uptake of rice plant. Recommended level of fertilizers, 6 kg N, 5 kg $P_2O_5$ and 4 kg $K_2O$ per 10a, were applied, and for N fertilizer urea, urea+N-serve, and $KNO_3$ were included. Four 30-day-old seedlings were transplanted in a waterlogged 9 L pot filled with Yuga series soil, and 3 pots were prepared in each N fertilizer treatment. Changes of soil redox potential and concentration of ${NH_4}^-$, ${NO_3}^-$, $Fe^{2+}$ and ${PO_4}^{3-}$ in soil solution at 10 cm depth were monitored, and also the growth and nutrient uptake of rice plants were measured. Concentration of ${NH_4}^+$ in soil solution was highest in urea+N-serve treatment, and followed by urea and $KNO_3$ treatments. Addition of N-serve could effectively inhibit nitrification in the soil. In the treatment of $KNO_3$, relatively higher ${NO_3}^-$ concentration was found at 10 cm depth soil. In urea+N-serve treatment redox potential was lower than -100 mV during the experiment, but in the treatment of $KNO_3$ the potential was maintained above 0 mV until ${NO_3}^-$ remaining in soil solution. Reduction of Fe(III) and solubilization of P were highly correlated with redox potential changes in the three N fertilizer treatments. Concentrations of Fe(II) and ${PO_4}^{3-}$ in soil solution at 10 cm depth were much higher in the urea+N-serve treatment. The most vigorous rice seedling growth was found in the urea treatment. Although the availability of N and P in soil was enhanced in the urea+N-serve treatment through the suppression of nitrification, excessive solubilization of Fe could limit the growth of rice plants.

  • https://doi.org/10.5338/KJEA.2010.29.4.336 인용 PDF KSCI

A Study on Non-verbal Communication of korean Shaman Clothing (한국 무복(巫服)의 비언어적 커뮤니케이션에 관한 연구 - 진도 씻김굿을 중심으로 -)

  • 양미경
    • Journal of the Korean Society of Costume
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    • v.31
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    • pp.5-16
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    • 1997

  • This paper studies in terms of nonverbal communication the roles of Gut-clothinbgs used in Jin-Do Sit-gim Gut are classified as follows: 1) The message communicated through the ordinary clothings of a shaman is that he or she is waiting to serve as a presider of a Gut ceremony actiong as a mediator between the spirtual and the human world. 2) The shaman clothings representing many kinds of spirits are visualized figures which are closely related to the common wishes of most people in society e. g. physical and material well-being longevity fertility. 3) The clothings serve as a body figure in the Gut are classified into 5 groups. (1) Laid-on clothings give the message that the body is standing still. (2) Wrapped clothings serve as an incarnated body of the dead. (3) Spread clothings represent a lying body. (4) Oscillated clothings are the symbols of a spirit which moves from this world to another. (5) Burned clothings mean that the spirit has attained a complete seperation from this world.

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Mathematical Modeling of the Tennis Serve: Adaptive Tasks from Middle and High School to College

  • Thomas Bardy;Rene Fehlmann
    • Research in Mathematical Education
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    • v.26 no.3
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    • pp.167-202
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    • 2023

  • A central problem of mathematics teaching worldwide is probably the insufficient adaptive handling of tasks-especially in computational practice phases and modeling tasks. All students in a classroom must often work on the same tasks. In the process, the high-achieving students are often underchallenged, and the low-achieving ones are overchallenged. This publication uses different modeling of the tennis serve as an example to show a possible solution to the problem and develops and discusses one adaptive task each for middle school, high school, and college using three mathematical models of the tennis serve each time. From model to model within the task, the complexity of the modeling increases, the mathematical or physical demands on the students increase, and the new modeling leads to more realistic results. The proposed models offer the possibility to address heterogeneous learning groups by their arrangement in the surface structure of the so-called parallel adaptive task and to stimulate adaptive mathematics teaching on the instructional topic of mathematical modeling. Models A through C are suitable for middle school instruction, models C through E for high school, and models E through G for college. The models are classified in the specific modeling cycle and its extension by a digital tool model, and individual modeling steps are explained. The advantages of the presented models regarding teaching and learning mathematical modeling are elaborated. In addition, we report our first teaching experiences with the developed parallel adaptive tasks.

  • https://doi.org/10.7468/jksmed.2023.26.3.167 인용 PDF