• 한국운동역학회지
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• 제27권2호
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• pp.99-108
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• 2017

Objective: The purpose of this study was to analyze the effects of skill level and width between feet on kinematic and kinetic variables during jump rope single under with both feet. Method: Fifteen subjects in the skilled group (age: $10.85{\pm}0.40yrs$, height: $142.13{\pm}5.41cm$, weight: $36.97{\pm}6.65kg$) and 15 subjects in the unskilled group (age: $10.85{\pm}0.40yrs$, height: $143.31{\pm}5.54cm$, weight: $40.81{\pm}10.39kg$) participated in this study. Results: Participants in the skilled group minimized the anteroposterior displacement of their center of mass by modifying the width between their feet and decreased the range of motion (ROM) of their trunk in the sagittal plane. The preferred width during the jump rope decreased by 5.61~6.11 cm (32~37%) in comparison to width during static standing. The induced width was increased by 16.44~16.67 cm (82~85%), regardless of skill level. The kinematic variables of the left and right legs of members of the unskilled group were significantly different from those of members in the skilled group regarding the ROM of the hip, knee, and ankle joint. Otherwise, the members of the skilled group were consistent in terms of the kinematic variables of the right and left legs. Conclusion: The preferred width between feet during the jump rope was found to be beneficial for maintaining dynamic stability. The unskilled group exhibited asymmetry in left and right motion within the ranges of motion of the ankle, knee, and hip joints, regardless of the width. Therefore, long-term accurate jump rope motions will contribute to an improvement in the left and right imbalances of the entire body.

• 생명과학회지
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• 제19권12호
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• pp.1821-1828
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• 2009

본 연구는 육상 투척선수들의 plometric training과 weight training 프로그램 훈련이 순발력 및 민첩성과 최대 근력의 운동능력 향상에 어떠한 영향을 가져오는지 검증하기 위하여 고등학교 재학 중인 투척선수 21명을 대상으로 plyometric training과 weight training을 10주간의 트레이닝을 실시하여 여자 집단(10명)과 남자 집단(11명)으로 분류하여 다음과 같은 결론을 얻었다. 순발력에 있어서 제자리멀리뛰기, 서전트 점프, 30 m 달리기는 트레이닝 전에 비해 두 집단 모두 향상도를 보였으며, 여자 집단이 더 높은 향상도를 나타냈다. 민첩성에 있어서 사이드스텝, 버피 스텝, 전신반응 테스트는 트레이닝 전에 비해 모두 향상도를 보였으며, 사이드스텝과 버피 스텝은 여자 집단이 더 높은 향상도를 나타냈으며, 전신반응 테스트는 남자 집단이 더 높은 향상도를 나타냈다. 하지 근력에 있어서 squat, leg press는 트레이닝 전에 비해 모두 향상도를 보였으며, 여자 집단이 더 높은 향상도를 나타냈다. 무릎 관절 등속성 근력에 있어서 왼쪽, 오른쪽 신근력과 굴근력은 트레이닝 전에 비해 모두 향상도를 보였으며, 왼쪽 신근력은 남자 집단이 더 높은 향상도를 나타냈으며, 왼쪽 굴근력, 오른쪽 신근력, 오른쪽 굴근력은 여자 집단이 더 높은 향상도를 나타냈다. 상지의 근력에 있어서 Bench press, 배근력은 트레이닝전에 비해 모두 향상도를 보였으며, 여자집단이 더 높은 향상도를 나타냈다.

• 한국가정과교육학회지
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• 제28권4호
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• pp.159-167
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• 2016

본 연구는 청소년의 우유 섭취, 영양 섭취 및 체력 간의 관계를 알아보고자 실시되었다. 시도교육청과 학교의 협조를 받아 선정한 중소도시에 거주하는 298명의 청소년을 대상으로 평소 식사 및 체력장 기록을 조사하였다. 우유 유제품 섭취는 식사조사를 이용해 파악하였고, 우유 유제품으로 섭취한 1일 평균 칼슘 섭취량을 우유 200 mL 중의 칼슘 함량과 비교해 1일 평균 우유칼슘당량을 구하였다. 식사조사는 식사기록법에 의해 주중 2일과 주말 1일을 포함하는 3일간 실시하였고, 식사조사지의 식사 내용을 CAN-Pro 3.0에 입력해 영양소 섭취량을 구한 후 1일 평균 영양소 섭취량을 산출하였다. 체력장 기록은 학교에서 정규적으로 실시하는 자료에 따랐다. 조사 대상 청소년의 1일 평균 우유칼슘당량은 우유칼슘당량을 기준으로 분류한 저섭취군(${\leq}0.29$/일), 중섭취군(0.30-0.78/일), 고섭취군(0.79-5.66/일)에서 모두 권장 수준인 '2'보다 낮아 조사대상자의 우유 섭취가 전반적으로 부족하였다. 1일 평균 우유칼슘당량이 높을수록 50 m 달리기와 제자리멀리뛰기 기록이 유의적으로 높았다. 그리고 대부분의 에너지 영양소, 비타민, 무기질의 1일 평균 섭취량과 50 m 달리기, 제자리멀기뛰기, 오래달리기 기록이 높은 방향으로 유의적인 상관관계가 있었다(p<0.05). 따라서 청소년기에 우유 섭취와 함께 균형잡힌 영양 섭취를 하면 체력 향상에 도움이 되므로 중등학교 가정교과의 식생활교육에서 청소년기에 1일 2컵의 우유 섭취를 실천하도록 지도해야 하며 아울러 중등학교의 학교우유급식 활성화를 위한 제도적 뒷받침도 이루어질 필요가 있다고 하겠다.

• Physical Therapy Rehabilitation Science
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• 제5권4호
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• pp.198-204
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• 2016

Objective: The purpose of this study was to examine the effects of hip joint exercise using an elastic band on dynamic balance, agility, and flexibility in healthy subjects. Design: Randomized controlled trial. Methods: Thirty-five subjects (between 19 and 23 years) were randomly allocated to two groups: hip flexion exercise (HFE) group (n=17) and the hip abduction exercise (HAE) group (n=18). The HFE group participated in flexion exercise of the hip joint using an elastic band for 50 minutes a day, three days a week for four weeks, while the HAE group participated in abduction exercises of the hip joint using an elastic band for the same period. Dynamic balance was measured using the timed up and go (TUG) test, agility was measured with the standing long jump, and flexibility was measured using the Schober's test (5 cm, 10 cm). Results: The HFE group showed significant differences in the TUG test, standing long jump, and the Schober's test (10 cm) after training (p<0.05). The HAE group showed significant differences in the TUG test, standing long jump and the Schober's test (5 cm, 10 cm) after training (p<0.05). However, there was no significant difference between the HFE group and the HAE group. Conclusions: Flexion and abduction exercises of the hip joint using and elastic band increased dynamic balance, agility, and flexibility in healthy subjects. Additional research on hip joint exercises using an elastic band for improving dynamic balance, agility and flexibility are necessary.

• 한국운동역학회지
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• 제21권5호
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• pp.503-510
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• 2011

The purpose of this study was to find the biomechanical research project result carried out at 2011 IAAF World championship in Daegu. This project was approved by the International Amateur Athletic Federation(IAAF) and financially supported by the Ministry of Culture, Sports and Tourism(MCST) and, Korea Association of Athletics Federations(KAAF). The total number of the project members was 20, including the members of the Scientific Committee, the Korean Society of Sport Biomechanics(KSSB) and graduate students as assistants. The objective of this project has been to analyze the performance in the track events(100 m, 110 mH) and field events(Long Jump, High Jump, Triple Jump, Pole Vault, Javelin Throw and Shot Put). This project was focused on the biomechanical research only. This kind of analysis has been carried out at major competitions for more than a decade, as it provides coaches and athletes with very useful information as an aid to training programmes and competition preparation. The biomechanical analysis of the top athletes in the world in each specialty serves as a reference for assessing technique and rationalizing the results achieved. The results will be disseminated world-wide and coaches will be in a better position to design training strategies in line with current world trends.

• 한국수자원학회논문집
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• 제48권2호
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• pp.137-147
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• 2015

본 논문에서는 홍천강과 섬진강을 대상으로 하천에 존재하는 다양한 형태의 여울을 체계적으로 분류하고, 물리적 및 수리학적 특성을 분석하였다. 여울의 길이와 폭 비율을 기준으로 긴 형태와 넓은 형태로 분류하고, 상 하류 폭의 변화 정도를 기준으로 집중 형태와 확산 형태로 분류하였다. 또한 흐름의 물결 형태에 따라 떨어지는 형태, 미끄러지는 형태, 약한 파도 및 약한 도수로 분류하였다. 떨어지는 형태와 미끄러지는 형태는 주로 큰 돌 주위의 다양한 입경을 지닌 하상에서 발생하였으며, 약한 파도와 약한 도수는 주로 잔 돌 주위에서 발생하였다. 여울의 흐름 방향 경사는 가운데 부분에서 위로 볼록하였으며, 하류측으로 갈수록 경사가 커졌다. 여울의 종적 구조에 따른 물결형태를 구분하여 보면, 여울의 집중 형태에서는 흐름 방향으로 약한 파도, 미끄러지는 형태 및 약한 도수가 발생하였다. 긴 형태의 경우, 흐름방향으로 약한 파도, 미끄러지는 형태 및 떨어지는 형태가 발생하였다. 넓은 형태의 여울에서는 약한 파도, 약한 도수 및 약한 파도, 약한 도수가 발생하였다.

• 복식
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• 제52권6호
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• pp.1-13
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• 2002

This paper investigated the costumes of young girl dancers in Yon wha dae moo(연화대무: Lotus Stage dance) which were documented on the Ak-hak-guae-bum(악학궤범: Protocol of music) and the Jin-yeon-eui-guae(진연의궤: Archives of Royal Feast). The fashion of the costumes can be changed into three phases, based mainly on the changes of Hap-rip(합립: silk hat), Dan-eui(단의: long jacket) and Sang(상: apron type skirt). In the first phase the costume consisted of Hap-rip, round neck-line Dan-eui and tiered skirt decorated with pleat and Yu-so(유소: decorated cords). In the second phase. it consisted of Hap-rip, v-shape neck-line Dan-eui and skirt without pleat. In the third phase, it consisted of Yeon-wha-gwan(연화관: Lotus shape cap), round neck-line Dan-eui of later era and skirt with pleat and Yu-so. Yon-wha-dae dance appears to be adopted from Ja-ji-mu( 자지무: chinese dance) that originated in West and Central Asia. In both dances. young girl dancers danced mainly jump and spin. The costume of round neck-line Dan-eui seems to have been affected by the fashion in Dang Dynasty when young girls loved to wear Dan-ryung(단령: male coat with round neckline). And it satisfied the need of mobility for the dance which was Performed mainly with jump.

• Asia pacific journal of information systems
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• 제7권1호
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• pp.67-83
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• 1997

The utility of learning techniques in investment analysis has been demonstrated in many areas, ranging from forecasting individual stocks to entire market indexes. To date, however, the application of artificial intelligence to financial forecasting has focused largely on short predictive horizons. Usually the forecast window is a single period ahead; if the input data involve daily observations, the forecast is for one day ahead; if monthly observations, then a month ahead; and so on. Thus far little work has been conducted on the efficacy of long-term prediction involving multiperiod forecasting. This paper examines the impact of alternative procedures for extended prediction using knowledge discovery techniques. One dimension in the study involves temporal granularity: a single jump from the present period to the end of the forecast window versus a web of short-term forecasts involving a sequence of single-period predictions. Another parameter relates to the numerosity of input variables: a technical approach involving only lagged observations of the target variable versus a fundamental approach involving multiple variables. The dual possibilities along each of the granularity and numerosity dimensions entail a total of 4 models. These models are first evaluated using neural networks, then compared against a multi-input jump model using case based reasoning. The computational models are examined in the context of forecasting the S&P 500 index.

• 한국기계가공학회지
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• 제14권4호
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• pp.21-27
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• 2015

Induction bending is a method that allows the bending of any material that conducts electricity. This technology applies a bending force to a material that has been locally heated by an eddy current induced by a fluctuating electromagnetic field. Induction bending uses an inductor to locally heat steel through induction. This results in a narrow heat band in the shape to be bent. In general, the reduction of thickness attenuation of a large-diameter steel pipe is not allowed to exceed 12.5%. In this paper, in order to meet the standard of thickness attenuation reduction, a non-uniform heating temperature jump-bending process was investigated. As a result, the developed bending technique meets the requirements of thickness attenuation reduction for large-diameter steel pipes.

• Journal of Acupuncture Research
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• 제26권2호
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• pp.171-179
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• 2009

Objectives: The purpose of this study was to investigate the changes of obesity, blood composition and physical ability in obese children on body weight control program. Methods : The body weight control program included exercise, nutrition education and auricular acupuncture was performed 4 times a week during 12 weeks. 32 obese children whose body fat ratio were over 30% participated in this study. Measuring materials were body composition(weight, muscle mass, fat mass, fat ratio, BMI), physical measurement(height, waist circumference, chest circumference, hip circumference), physical ability(grip strength, sit-ups, sitting trunk flexion, sit-down stand-up test, standing long jump, opened eyes foot balance, side step), blood composition(WBC, Hb, ESR, Total Cholesterol, TG, GOT, GPT, BUN, Creatinine, Glucose) and survey(changes of eating habits, changes of living habits, knowledge of obesity, self-confidence, self-esteem). Results : From the results, positive changes were made in BMI, height, waist circumferences, chest circumferences, hip circumferences, sit-ups, sitting trunk flexion, sit-down stand-up test, standing long jump, opened eyes foot balance, side step, Hb, ESR, GOT, GPT and changes of eating habits through the body weight control program. Conclusions : This results suggest that body weight control program including exercise, nutrition education and auricular acupuncture may be effective for helping obese children.