• Title/Summary/Keyword: momentum

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Analysis of the Angular Momentum for the Bar Clearance Motion in the Fosbury Flop (높이뛰기의 바 넘기 동작을 위한 각운동량 분석)

  • Sung, Rak-Joon
    • Korean Journal of Sport Biomechanics
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    • v.14 no.3
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    • pp.119-134
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    • 2004
  • The purpose of this study was to analyze the angular momentum characteristics of the Fosbury Flop high jump and the role of the body segments for the production of 3 angular momentum components. The subjects were three male jumpers who were former Korean national team players. Their jumping motions were analyzed using the DLT method of three-dimensional cinematography. The conclusions were as follows. 1. All the forward angular momentum needed to clear the bar was created in the take-off phase. Take-off leg was the great contributor of the forward angular momentum. On the other hand, free leg produced large opposite angular momentum. 2. All subject had some lateral angular momentum before the take-off phase. Head and free leg had major contribution to the lateral angular momentum production. Take-off leg produced opposite angular momentum. 3. All subject had some twisting angular momentum, which make the back of the athlete him to the bar, before the take-off phase. Free leg was the major contributor of the twisting angular momentum. Head and trunk was the second contributor of the twisting angular momentum. 4. Total angular momentum needed to clear the bar had no significant correlation to the jumping height. 5. Subject who made excessive angular momentum showed different pattern of angular momentum production and had a poor record compared to other subject.

Momentum Effect in the Oman Stock Market Over the Period of 2005-2018

  • GHARAIBEH, Omar Khlaif;AL-KHAZALI, Ahmad;AL-QURAN, Ali Zkariya
    • The Journal of Asian Finance, Economics and Business
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    • v.8 no.2
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    • pp.711-724
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    • 2021
  • The purpose of this paper is to investigate the profitability of the momentum effects on the Oman Stock Market (OSM). This study uses the monthly returns of all stocks listed on the OSM, with a total of 107 companies used in the study for the period from 2005 to 2018. According to the methodology developed by Jegadeesh and Titman (1993), this study builds momentum portfolios based on various sizes. Moreover, the January effect is also examined to recognize if this effect is related to the momentum effect. The results find that there is evidence of momentum returns and these returns are statistically and economically significant. The sub-periods confirmed the profitability of the momentum strategy. This paper shows that momentum returns are evident at different sizes; big, medium, and small-sized portfolios. Besides, the result shows that the classic January effect does not play an important role in the momentum returns. Thus, the implication is that the momentum should not take into account the annual, seasonal, and size returns. The capital asset pricing model (CAPM) or the three-factor model cannot explain momentum returns generated by individual stocks in the Oman Stock Market. These results are useful to academia and investors alike.

Roll/Yaw Momentum Management Method of Pitch Momentum Biased Spacecraft (피치 모멘텀 바이어스 위성시스템의 롤/요축 모멘텀 제어방식)

  • Rhee, Seung-Wu;Ko, Hyun-Chul;Jang, Woo-Young;Son, Jun-Won
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.37 no.7
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    • pp.669-677
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    • 2009
  • In general, the pitch momentum biased system that induces inherently nutational motion in roll/yaw plane, has been adapted for geosynchronous communications satellites. This paper discusses the method of roll attitude control using yaw axis momentum management method for a low earth orbit(LEO) satellite which is a pitch momentum biased system equipped with only two reaction wheels. The robustness of wheel momentum management method with PI-controller is investigated comparing with wheel torque control method. The transfer function of roll/yaw axis momentum management system that is useful for attitude controller design is derived. The disturbance effect of roll/yaw axis momentum management system for attitude control is investigated to identify design parameters such as magnitude of momentum bias and to get the insight for controller design. As an example, the PID controller design result of momentum management system for roll/yaw axis control is provided and the simulation results are presented to provide further physical insight into the momentum management system.

Analysis of intraday price momentum effect based on patterns using dynamic time warping (DTW를 이용한 패턴 기반 일중 price momentum 효과 분석)

  • Lee, Chunju;Ahn, Wonbin;Oh, Kyong Joo
    • Journal of the Korean Data and Information Science Society
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    • v.28 no.4
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    • pp.819-829
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    • 2017
  • The aim of this study is to analyze intraday price momentum. When price trends are formed, price momentum is the phenomenon that future prices tend to follow the trend. When the market opened and closed, a U-shaped trading volume pattern in which the trading volume was concentrated was observed. In this paper, we defined price momentum as the 10 minute trend after market opening is maintained until the end of market. The strategy is to determine buying and selling in accordance with the price change in the initial 10 minutes and liquidating at closing price. In this study, the strategy was empirically analyzed by using minute data, and it showed effectiveness, indicating the presence of an intraday price momentum. A pattern in which returns are increasing at an early stage is called a J-shaped pattern. If the J-shaped pattern occurs, we have found that the price momentum phenomenon tends to be stronger than otherwise. The DTW algorithm, which is well known in the field of pattern recognition, was used for J-shaped pattern recognition and the algorithm was effective in predicting intraday price movements. This study showed that intraday price momentum exists in the KOSPI200 futures market.

The Analysis of the transfer of angular momentum on upper extremity during free Throw Motion in Basketball (농구 자유투 동작시 상지분절의 각운동량 전이 분석)

  • Yang, Dong-Young
    • Korean Journal of Sport Biomechanics
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    • v.13 no.1
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    • pp.185-204
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    • 2003
  • The purpose of this study was to obtain the data for stable and accurate techniques of the free throw in basketball. The subjects of this study were seven male basketball player consisted of college students athletes. Free throw motions were taken by video camera. The three-dimensional coordinates was processed by DLT. The variables were the velocity, the angular velocity of the upper extremity segments, degree, and angular momentum. The result of analysis is summarized as follows. 1. The velocity and angular velocity of the upper extremity segment was showed an gradual increase and a smooth velocity transfer, transferring from proximal segment to distal segment at free throw motion in basketball. 2. The local term and remote term angular velocity momentum of the proximal segment showed larger than that of the distal segment in X, Y, Z axis component all. 3. The remote term angular momentum was showed larger than that of the local term angular momentum in X, Y, Z axis component all. 4. The angular motion of the upper trunk and upper arm, upper arm and forearm was showed in opposite direction and symmetrical angular momentum in local term angular momentum of the Y and Z axis component. 5. All the segments of upper extremity segment was showed left rotation in remote term angular momentum of the Y axis component and right rotation in remote term angular momentum of the Z axis component.

Reaction Wheel Momentum Dumping with Magnetic Torquer Failure (자기토커 고장시 반작용휠 모멘텀 덤핑)

  • Son, Jun-Won
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.47 no.5
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    • pp.371-378
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    • 2019
  • High precision pointing satellite uses the reaction wheels for the attitude control and their momentum dumping is performed by the three magnetic torquers. In this paper, the effects of one magnetic torquer's failure on the momentum dumping will be reviewed. When the satellite on the high inclination angle orbit holds LVLH (Local Vertical Local Horizontal) attitude, pitch axis magnetic torquer failure causes the momentum dumping failure. But in case of other torquer's failure, momentum dumping is still possible with degraded dumping performance. When pitch axis magnetic torquer fails, momentum dumping is possible by changing the satellite attitude. This paper propose the satellite attitude change to make the momentum dumping possible when pitch axis magnetic torquer fails. In addition, if torquer arrangement is modified, momentum dumping is always possible regardless of any torquer's failure.

Performance and Root Mean Squared Error of Kernel Relaxation by the Dynamic Change of the Moment (모멘트의 동적 변환에 의한 Kernel Relaxation의 성능과 RMSE)

  • 김은미;이배호
    • Journal of Korea Multimedia Society
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    • v.6 no.5
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    • pp.788-796
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    • 2003
  • This paper proposes using dynamic momentum for squential learning method. Using The dynamic momentum improves convergence speed and performance by the variable momentum, also can identify it in the RMSE(root mean squared error). The proposed method is reflected using variable momentum according to current state. While static momentum is equally influenced on the whole, dynamic momentum algorithm can control the convergence rate and performance. According to the variable change of momentum by training. Unlike former classification and regression problems, this paper confirms both performance and regression rate of the dynamic momentum. Using RMSE(root mean square error ), which is one of the regression methods. The proposed dynamic momentum has been applied to the kernel adatron and kernel relaxation as the new sequential learning method of support vector machine presented recently. In order to show the efficiency of the proposed algorithm, SONAR data, the neural network classifier standard evaluation data, are used. The simulation result using the dynamic momentum has a better convergence rate, performance and RMSE than those using the static moment, respectively.

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Momentum and Ownership: The Evidence of Taiwan Stock Market (모멘텀과 투자자 지분율: 대만 주식시장)

  • Wu, Ming;Ko, Kwangsoo
    • Journal of the Korean Data Analysis Society
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    • v.20 no.6
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    • pp.3025-3035
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    • 2018
  • This study investigates the momentum phenomena of stocks listed on the taiwan stock exchange. The purpose of this study is to examine the differences in momentum phenomena among firm size, foreign investor ownership, individual investor ownership, and institutional investor ownership. The empirical results of the momentum phenomenon in the Taiwanese stock market are as follows. First, there is no momentum phenomenon during the whole sample period. Second, momentum profitability does not exist even if this study divides by firm size. However, the results are different if this study divides it by the investor ownership. Third, there is a significant positive momentum for firms with high individual ownership. Fourth, on the contrary, positive momentum was observed in firms with low institutional ownership. Finally, there was no momentum phenomenon when dividing by foreign ownership. This study has academic contribution in analyzing the momentum phenomenon in Taiwanese stock market considering the investor's ownership.

An Analysis of Patterns and Characteristics of Momentum Effect on Learning Science Concepts (과학개념 학습지속 효과의 유형과 그 특성 분석)

  • Kwon, Jae-Sool;Kim, Jun-Tae
    • Journal of The Korean Association For Science Education
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    • v.12 no.1
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    • pp.11-21
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    • 1992
  • This study tried to find out the effect to types of test items upon the momentum effect. The previous studies showed that the momentum effect is influenced by stduents' congnitive levels and the abstractness of test items. In this study focused on the types of test items The test items are divided into 4 different types of quantitative and qualitative, verbal and image. The result showed that qualitative items showed a longer momentum effect than quantitative ones. The image items and verbal items did not show significant difference in the duration of momentum effect. The interpretation of this would need a careful psychological analysis. Anyhow, this result reconfirmed the existence of the momentum effect and showed that the study on the momentum effect could be a Significant research paradigm.

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Angular Momentum Effect of Electron Scattering with Reduced Angular Momentum Expansion (축약 각운동량 전개(Reduced Angular Momentum Expansion) 방법으로 해석한 전자 산란의 각 운동량 효과)

  • Kang, J.H.
    • Journal of the Korean Magnetics Society
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    • v.18 no.1
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    • pp.36-38
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    • 2008
  • We calculate the electron scattering amplitude with reduced angular momentum expansion(RAME) and compare it with the plane wave approximation. By using WKB approximation it is shown that the curvature correction factor given by RAME is originated from the source wave centrifugal potential energy. The factor also can be understood as an effective wave number correction factor in plane wave approximation. Angular momentum and its relationship with scattering amplitude is explicitly shown.