위기 말고, 프로그램을 만들라

정용민 한국방송협회 2019 방송문화 Vol.- No.419

유도선수의 웨이트트레이닝 시 각 관절별적정 중량부하에 관한 연구

정용민,방현석 한국웰니스학회 2013 한국웰니스학회지 Vol.8 No.4

본 연구는 대학유도선수들을 대상으로 웨이트트레이닝 시 중량의 부하를 1RM의 50%, 65%, 80%로 각각 설정하여 각 관절별근력과 근지구력을 효과적으로 증가시킬 수 있는 적절한 부하량을 알아보기 위함이다. 대상자는 3년 이상 선수생활 및 광역시?도대회 4강 이내에 입상한 경험이 있는 유도선수 22명으로 하였다. 자료처리는 SPSS 18.0 program을 사용하여 공변량 분석을 실시하였다. 연구결과 운동 전·후의 비교에서 모든 관절의 신전과 굴곡 근력은 50%, 65%, 80% 부하 집단이 운동 후 모두 유의하게증가되었다. 운동 전 근력을 공변량으로 하여 운동 후 근력에 대한 공변량 분석 결과 신근은 견관절, 주관절과 슬관절에서 80%집단이 50%집단과 65%집단보다 높게 나타났다. 굴근은 견관절과 주관절에서 80%집단이 65%집단과 50%집단보다 높게 나타났고, 슬관절은 80%집단이 50%집단보다 높게 나타났다. 근지구력은 신전과 굴곡의 운동 전·후를 비교한 결과 50%, 65%, 80% 부하 집단의 모든 관절에서 운동 후 유의하게 증가되었지만, 집단 간 유의한 차이는 나타나지 않았다. 종합하여 볼 때 유도선수들의 웨이트트레이닝 시 견관절, 주관절, 슬관절의 근력 증가를 위해서는 1RM 80%의 고 중량을 사용하여 훈련하는 것이 바람직하며, 근지구력은 운동부하량의 구분 없이 지속적인 웨이트트레이닝 실시만으로 근지구력이 증가될 수 있다는 결론을 얻었다. In this study, we set each 50%, 65%, and 80% load of 1RM for college Judo athletes’ weight training. the purpose is to determine the proper load which can effectively increase the muscular endurance and strength of each joint. The subjects were 22 Judo athletes who have three years or more experience and won up semi-final of metropolitan cities and provinces tournament. The data processing was performed ANCOVA using SPSS18.0 program. Results of the study, both extension and flexion muscular strength of all joints under 50%, 65%, 80% groups of after exercise showed significant increase, compared before and after exercise. Result of ANCOVA for muscular strength of after exercise as covariance before muscular strength, in the case of the extension muscles, 80% group was higher than the 65% and 50% group in the shoulder, elbow, and knee joint. in the case of flexion muscles, 80% group was higher than the 65% and 50% in shoulder and elbow joint, and 80% group was higher than 50% group in knee joint. all joints of extension and flexion muscular endurance under 50%, 65%, 80% groups were increased significantly after exercise. there was no significant difference between groups. Comprehensively, for increase the muscular strength of shoulder, elbow and knee joints of Judo players, the use of high weight 80% of 1RM is desirable, and muscular endurance is increased just do the weight training continued without distinction of exercise load. was concluded.

Wavelet Transform 을 이용한 천이 수중 신호의 특징 벡타 추출 기법 ( Feature Vector Extraction Method for Transient Sonar Signals Using Wavelet Transform )

정용민,조용수,오원천 대한전자공학회 1995 대한전자공학회 학술대회 Vol.1995 No.7

한국어 단모음 인식을 위한 3차 Cumulant를 이용한 특정 벡터 추출 알고리즘 ( Algorithms for Feature Vector Extraction Using Third order Cumulants to Recognize Korean Single-Vowel )

정용민,조용수 대한전자공학회 1994 대한전자공학회 학술대회 Vol.1994 No.1

외부 굴절률 측정을 위한 초소형 에탈론 제작 및 그 응용

정용민,정윤송,김준기,유성우,오경환 한국통신학회 2004 한국통신학회 기타 간행물 Vol.2004 No.11

코치의 리더십행동의 불일치와 성취동기와의 관계

鄭容敏,表內淑 釜山大學校 師範大學 1994 교사교육연구 Vol.28 No.-

The purpose of this study was to show a coaching leadership style by investigating the relationship between discrepancy of leadership behavior and achievement motivaton. Questionnaires were given to 776 players(87 teams) of 9 sports belonging to middle and high schools in Pusan, and finally 695 questionnaires were analysed based on response set. The questionnaires were composed of three parts : 1) the LSS (Leadership Scale for Sports) by Chelladurai and Saleh(1980), 2) the scale of Competition-Related Motives in Sports by Willis(1982), 3) personal characteristics of players. Those materials were subjected to a series of statistical analyses. Item-to-total-correlation was used for item validity of the scales and Cronbach'α for internal consistency in items. Also, t-Test was available to identify the relationship between discrepancy of leadership behavor and achievement motivation. After those analyses of the data, the following conclusion could be drawn : 1. The most preferred leadership style is traininng and instruction, on the other hand, the least is autocratic behavior. So traininng and instruction is perceived best but autocratic behavior are not. 2. In democratic behavior the discrepancy is most excessive and in positive feedback it is quite the opposite. 3. In the relationship of the discrepancy of leadership style and achievement motivaton, there is significant difference with the discrepancy of traininng and instruction, autocratic behavior, and social support.

A thermo-mechanical stress prediction improvement of using the classical lamination theory via Saint-Venant’s principle for laminated composite plates

정용민,김준식 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.2

Saint-Venant’s principle was introduced as the principle of the stress resultant equivalence for one dimensional structures, such as beams, cylindrical and prismatic structures. According to the principle, the stress distributions may be different around the area where forces are applied, but their resultants are invariant. In this paper, we apply the Saint-Venant’s principle to improve the thermomechanical stresses calculated by the Classical lamination theory (CLT). First we solve the CLT for laminated composite plates, calculate the transverse shear stresses using three-dimensional stress equilibrium equations, and obtain the improved displacement field with perturbation terms via transverse shear constitutive equations. At this point, these perturbation terms are unknown, which can be determined by applying the stress resultant equivalence (or the Saint-Venant’s principle). Once the terms are calculated, the improved displacements and stresses are obtained. To verify the accuracy of the proposed approach, simply-supported plates under mechanical and/or thermal loadings are taken as a test-bed, in which symmetric and anti-symmetric cross-ply layups are considered. The results obtained are compared to those of three-dimensional elasticity as well as first-order shear deformation theory. Finally the errors induced by the present approach are systematically analyzed in terms of the stress resultants.

다기능 5축 복합가공기 구조 최적설계 및 동강성 평가

정용민,장성현,황현영,최영휴,하종식 한국공작기계학회 2008 한국공작기계학회 추계학술대회논문집 Vol.2008 No.-

This paper describes a structural design. optimization for light weight and minimum compliance using G.A. and a study on dynamic stiffness evaluation of a 5-axes multi-tasking machine tool. Dynamic stiffness is one of important factors regarding to machine tool accuracy. In design optimization, we optimized the thickness of structural member which minimize the compliance and weight of the machine structure under several constraints. Furthermore, dynamic stiffness, in this study, were obtained by using both FEM analysis and an experimental dynamic stiffness test, that is a random excitation test by using a hydraulic exciter. Both the theoretical and experiment analysis results showed good agreement with each other. Finally, some discussion and review from the view point absolute dynamic stiffness were made based on the analysis results.

면외 워핑함수를 고려한 보 구조물의 기계 및 열응력 해석

정용민,김준식 한국전산구조공학회 2016 한국전산구조공학회논문집 Vol.29 No.3

본 논문에서는 기존에 개발된 생브낭의 원리를 이용한 응력개선방법에 부가적인 면외 워핑함수를 도입하여 후처리함으로써 기계 및 열응력을 개선할 수 있는 방법을 소개하였다. 열응력 예측이 중요한 문제로 다루어지고 있으며, 이에 따라 수많은 보이론들이 개발되어왔다. 일반적으로 고차이론들이 열응력 예측에 유용하다고 알려져 있지만, 자유도가 많아 계산과정이 복잡하다는 단점이 존재한다. 이러한 단점들을 보완하기 위해, 본 연구에서는 계산이 비교적 간단한 고전 보이론의 변위장에 면외 워핑함수를 부가적으로 도입하고 합응력 등가를 통해 후처리함으로써 보 구조물의 열응력을 정확하게 예측할 수 있는 방법을 제시하였다. 그리고 다양한 경계조건을 가지는 수치예제들을 통해 탄성해와 비교함으로써 그 정확도를 검증하고, 면외 워핑함수가 응력개선에 미치는 영향에 대해 분석하였다. In this paper, a methodology, which is able to predict the thermal stresses accurately yet efficiently, is presented for beam structures via Saint-Venant’s principle. In general, higher-order beam theories have been known to be effective for the prediction of thermal stresses. In contrast to this, we propose the method to predict the thermal stresses of beam structures by post-processing the classical beam theory via Saint-Venant’s principle. The approach includes an out-of-plane warping displacement to account for the through-the-thickness thermal deformation. With this, one can accurately recover the thermal stresses as compared to the elasticity solutions. In fact, they are identical for the beams made of isotropic materials. The effect of out-of-plane warping is also investigated, it turns out that the effect is negligible in mechanical stress analysis but not in thermal stress analysis.

『통일시민』과 시민성교육을 통한 통일교육

정용민 한국도덕윤리과교육학회 2018 한국도덕윤리과교육학회 학술대회 자료집 Vol.2018 No.08