• 한국생활과학회지
• /
• 제19권2호
• /
• pp.271-283
• /
• 2010

This study was planned to investigate the effects of mathematical games with motion on young children's development. The study was performed to compose mathematical games with motion and just mathematical games for young children. The games were set up to be executed 16 times for 8 weeks. The results of this study were as follows: Mathematical games with motion had a significant effect on young children's mathematical problem-solving ability. Mathematical games with motion had a significant effect in every category on young children's ability for motion competence and mathematical games with motion had a significant effect on young children's socio-emotional development. There were significant differences between the control group and the experimental group except for the independence from teachers and peer interaction. Mathematical games with motion had a significant effect on young children's language ability.

• 한국지진공학회논문집
• /
• 제24권1호
• /
• pp.9-17
• /
• 2020

The stochastic point-source model has been widely used in generating artificial ground motions, which can be used to develop a ground motion prediction equation and to evaluate the seismic risk of structures. This model mainly consists of three different functions representing source, path, and site effects. The path effect is used to emulate decay in ground motion in accordance with distance from the source. In the stochastic point-source model, the path attenuation effect is taken into account by using the geometrical attenuation effect and the inelastic attenuation effect. The aim of this study is to develop accurate equations of ground motion attenuation in the Korean peninsula. In this study, attenuation was estimated and validated by using a stochastic point source model and observed ground motion recordings for the Korean peninsula.

• 전자공학회논문지S
• /
• 제35S권5호
• /
• pp.68-74
• /
• 1998

Block-based interframe interpolation algorithms cause severe block effect because the algorithm interpolates the skipped frame by using block based motion vector. Therefore, in this paper, we propose an algorithm that reduces the block effect in the interpolated frames. First, we propose an algorithm that obtains backward motion vector by using forward motion vector received from the transmitter. In order to predict well covered and uncovered region, backward motion vector is needed as well as forward motion vector. Second, we propose the algorithm which segments the motion boundary blocks into regions and obtains the motion vector of each region from candidates that consist of the motion vectors of neighbor blocks. This algorithm makes it possible that the moving object and the background, in spite of being in the same block, have different motion vectors from each other so that the block effect can be reduced. According to the results of simulation, the proposed algorithm is superior to conventional algorithm in subjective quality a swell as in objective quality.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 2000년도 추계학술대회 논문집
• /
• pp.179-183
• /
• 2000

This paper is concerned with achieving the high motion accuracy of linear motion bearing guide according to estimate accuracy average effect of bearing. Accuracy average effect can be obtained b analysis the relationship between motion error of the table and spatial frequency of the rail form error. And influences of ball diameter, ball number, and clock length on block motion error and block number on the table motion error are analyzed theoretically. In addition to, a simple experiment is performed in order to verify theoretical result.

• Smart Structures and Systems
• /
• 제19권4호
• /
• pp.415-429
• /
• 2017

This paper focuses on the impact of the wave passage effect on the long-span bridge. In order to make the wave passage effect more obvious, ground motion samples are selected from the near-fault ground motion of the 1999 Chi-Chi earthquake and an arch bridge with a 280m main span is selected as a bridge sample. The motion ground samples are divided into two groups according to the characteristics of near-fault. A sequence of fragility curves is developed. It is shown that the seismic damage is increased by the wave passage effect and the increase is more obvious in the near-fault ground motion.

• 대한조선학회논문집
• /
• 제44권3호
• /
• pp.267-278
• /
• 2007

This experimental study investigated on the eddy making effect on the roll motion of a rectangular barge in a two-dimensional wave tank. The structure was used to simulate a simplified rectangular barge in the beam sea condition. The structure with a draft one half of its height was hinged at the center of gravity and free to roll by waves. The rectangular barge was tested with regular waves with a range of wave periods that are shorter, equal to, and longer than its roll natural period. Particle image velocimetry (PIV) was employed to obtain the velocity field in the vicinity of the structure. The coupled interactions between the incident wave and the barge were demonstrated by examining the vortical flow fields to elucidate the eddy making effect during the roll motion. For incoming wave with a wave period same as the roll natural period, the barge roll motion was reduced by the eddy making damping effect. At the wave period shorter than the roll natural period, the structure roll motion was slightly reduced by the vertical flow around the barge. However, at the wave period longer than the roll natural period, the eddy making effect due to flow separation at structure corners indeed amplifies the roll motion. This indicates that not only can the eddy making effect damp out the roll motion, it can also increase the roll motion.

• 산업공학
• /
• 제17권2호
• /
• pp.218-225
• /
• 2004

This study aims to investigate effect of external load and motion repetitiveness on perceived discomfort. An experiment was performed for measuring discomfort scores at varying conditions, in which external load, motion repetitiveness and arm posture were employed as experimental variables. The arm posture was controlled by shoulder flexion and abduction, and by elbow flexion. Fifteen healthy college-age students without history of musculoskeletal disorders voluntarily participated in the experiment. The results showed that the effect of external load, motion repetitiveness and shoulder posture on discomfort were statistically significant, but that elbow posture did not significantly affect discomfort ratings. The effect of external load was much larger than that of any other variables, and that of repetitiveness was second only to external load. Discomfort scores significantly increased linearly as the levels of external load and motion repetitiveness increased. This implies that although they were not fully reflected in the existing posture classification scheme such as OWAS, RULA, etc., the effect of external load and motion repetitiveness should be taken into consideration for precisely quantifying work load in industry. Based on regression analysis, equivalent values of external load and motion repetitiveness in terms of discomfort scores were provided, which would be useful for better understanding the degree of their effect on work load.

• 한국항해항만학회지
• /
• 제27권5호
• /
• pp.451-458
• /
• 2003

일반적으로 메타센터높이가 작은 선박이나 고속선의 경우에는 조종운동 시 큰 횡동요각을 유발하는 것으로 알려져 있다. 이러한 선박의 조종성능 예측 시에는 조종운동에 횡동요의 영향을 고려해야만 보다 정확한 결과를 얻을 수가 있다 즉, 조종운동을 다루는 전후동요, 좌우동요, 선수동요에 횡동요를 포함시키는 4자유도 운동방정식이 요구된다. 본 연구에서는 지금까지 여러 연구자들에 의해 제안되어 있는 4자유도 조종운동 수학모델을 검토 분석하고, 이들 실험자료를 재정리하여 보다 간결하고 실용적인 새로운 수학모델을 제안한다. 아울러 기존의 복잡한 수학모델과 새로운 수차모델에 의한 조종운동 시뮬레이션을 각각 수행하고 그 결과를 비교 검토하여 본 연구에서 제안한 수학모델의 유용성을 검증한다.

• Geomechanics and Engineering
• /
• 제29권2호
• /
• pp.133-143
• /
• 2022

The catastrophic earthquake-induced failure of slopes concentrically distributed at near-fault area, which indicated the special features of near-fault ground motions, i.e. horizontal pulse-like motion and large vertical component, should have great effect on these geo-disasters. We performed shaking table tests to investigate the effect of both horizontal pulse-like motion and vertical component on dynamic response of slope. Both unidirectional (i.e., horizontal or vertical motions) and bidirectional (i.e., horizontal and vertical components) motions are applied to soft rock slope model, and acceleration at different locations is reordered. The results show that the horizontal acceleration amplification factor (AAF) increases with height. Moreover, the horizontal AAF under unidirectional horizontal pulse-like excitations is larger than that subject to ordinary motion. The vertical AAF does not show an elevation amplification effect. The seismic response of slope under different bidirectional excitations is also different: (1) The horizontal AAF is roughly constant under horizontal pulse-like excitations with and without vertical waves, but (2) the horizontal AAF under ordinary bidirectional ground motions is larger than that under unidirectional ordinary motion. Above phenomena indicate that vertical component has limited effect on seismic response when the horizontal component is pulse-like ground motion, but it can greatly enhance seismic response of slope under ordinary horizontal motion. Moreover, the vertical AAF is enhanced by horizontal motion in both horizontal pulse-like and ordinary motion. Thence, we should pay enough attention to vertical ground motion, especially its horizontal component is ordinary ground motion.

• 한국실내디자인학회논문집
• /
• 제23권5호
• /
• pp.25-32
• /
• 2014

The purpose of this study is to analyze the expression method and visual characteristics of material utilized the lighting in terms of a visual aspect. The method of study is to establish standards for analysis and to classify type of visual effect and expression of that focused on preliminary study. And It is to grasp the visual expression characteristics of new materials. through analysis standards. The results of the study are as follows. First, 'decorativeness', 'symbolization', 'motion-images' and 'interactivity' were selected as the type of visual expression through the precedent studies. And it was classified the visual effects as 3 types like 'a light-emitting effect', 'steric effects' and 'movement effect'. Second, We could know that 'light-emitting effect' was expressed in 7-new materials, 'three-dimensional effect' was expressed in 3-new materials, and 'motion effect' in 4-new materials. Through that. We could know that the new materials represented with 'light-emitting effect' are much more than the other new materials. Third, the results of this study show that 'decorativeness' in the visual types was appeared to 'light-emitting effect' and 'three-dimensional effect'. 'symbolization' to 'light-emitting effect' and 'motion effect', 'motion-images' to 'three-dimensional effect' and 'motion effect' and 'interactivity' to 'light-emitting effect', 'three-dimensional effect' and 'motion effect'. And It was appeared to three effects in 'interactivity'. We could know that it is more effective to be presented the visual effect simultaneously to communication with the visual perception.