• 한국운동역학회지
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• 제24권3호
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• pp.229-238
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• 2014

This study comparatively analyzed the speed and segment coordination characteristics of Taekwondo hand techniques, while different attention focusing strategies were utilized. Ten elite Taekwondo poomsae athletes participated, and three different strategies (no focus, target focus, body focus) were utilized in random order. The hand velocity and upper body segment coordination characteristics were analyzed, with the following results. First, the maximum magnitudes of the hand velocity differed between the focus conditions for the Araenaereomakgi and Momtongjireugi techniques. Second, the angular velocity and kinetic energy transfer patterns of the segments differed between the focus conditions, and in the case of the body focus condition, the movement was more correct according to the theory. Third, the shoulder and elbow joint coordination patterns differed between the focus conditions, with more efficient movement shown with the body focus condition. In conclusion, we confirmed the potential of effectively using an attention focusing strategy in a taekwondo teaching situation. However, the effect on the movement coordination and results of the movement could be changed by a difference in the cue provided or the type of the task. In addition, depending on the task, the attention focusing strategy could affect the efficiency of the movement. Therefore, coaches and masters of Taekwondo will have to constitute determine the appropriate attention focusing cues based on the task.

• 한국해양환경ㆍ에너지학회지
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• 제5권1호
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• pp.11-18
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• 2002

방향 및 주파수 성분을 포함하는 파랑집중에 의해 다방향 쇄파를 생성하였으며, 등기울기 및 등진폭 스펙트럼 모델을 적용하였다. 생성된 다방향 쇄파는 초기쇄파, 단일쇄파 다중쇄파로 구분된다. 다방향 쇄파의 특성을 파정 기울기 및 비대칭성으로 정의되는 파형인자들의 함수로 고찰하였다. 또한 파랑집중의 효율성 관점에서 쇄파 파랑특성의 전개를 분석하였다. 파정 전면 기울기 및 연직 비대칭성은 쇄파과정에 영향을 미치는 중요한 인자이나, 파정후면 기울기 및 수평 비대칭성은 쇄파 과정에서 거의 상수 값을 갖는다. 방향 성분의 중첩은 파랑집중의 효율성을 크게 강화하며, 이는 다방향파의 쇄파 특성이 일방향파의 쇄파 특성과 상이함을 나타낸다.

• 융복합기술연구소 논문집
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• 제11권1호
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• pp.7-12
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• 2021

The magnetic gear, which amplifies the torque by filtering the magnetic field generated by the low-speed permanent magnet with a modulator, can exclude gear contact and can be effectively applied when there are environmental restrictions. In this paper, we discuss the magnetic force characteristics of a magnetic gear using a magnetic focusing array that replaces a general permanent magnet array magnetized in a radial direction along the circumferential direction. The torque increasing effect of the discussed array, known as an arrangement that increases the principal component by focusing a radial magnetic field, is compared with that of a general magnetic gear. In particular, in a magnetic gear using such an array, the sensitivity of torque according to variables is analyzed to see how various variables known as factors affecting torque have an effect.

• Current Optics and Photonics
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• 제4권1호
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• pp.9-15
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• 2020

Fresnel zone plates have been widely used in many applications, such as x-ray telescopes, microfluorescence, and microimaging. To obtain an x-ray Fresnel zone plate, many fabrication methods, such as electron-beam etching, ion-beam etching and chemical etching, have been developed. Fresnel zone plates fabricated by these methods will inevitably lead to some nonideal factors, which have an impact on the focusing characteristics of the zone plate. In this paper, the influences of these nonideal factors on the focusing characteristics of the zone plate are studied systematically, by numerical simulations based on scalar diffraction theory. The influence of the thickness of a Fresnel zone plate on the absolute focusing efficiency is calculated for a given incident x-ray's wavelength. The diffraction efficiency and size of the focal spot are calculated for different incline angles of the groove. The simulations of zone plates without struts, with regular struts, and with random struts are carried out, to study the effects of struts on the focusing characteristics of a zone plate. When a Fresnel zone plate is used to focus an ultrashort x-ray pulse, the effect of zone-plate structure on the final pulse duration is also discussed.

• IEIE Transactions on Smart Processing and Computing
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• 제1권3호
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• pp.133-142
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• 2012

This paper presents a salient region detection algorithm for auto-focusing based on the characteristics of a human's visual attention. To describe the saliency at the local, regional, and global levels, this paper proposes a set of novel features including multi-scale local contrast, variance, center-surround entropy, and closeness to the center. Those features are then prioritized to produce a saliency map. The major advantage of the proposed approach is twofold; i) robustness to changes in focus and ii) low computational complexity. The experimental results showed that the proposed method outperforms the existing low-level feature-based methods in the sense of both robustness and accuracy for auto-focusing.

• 한국해양공학회지
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• 제16권5호
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• pp.1-6
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• 2002

Extreme waves are generated in a model basin based on directional wave focusing. The targeted wave field is described by double summation method and it is applied to serpent-type wavemaker system. The extreme crest amplitude at a designed location is obtained by syncronizing the phases and focusing the directions of wave components. Two distinguished spectrums of constant wave amplitude and constant wave steepness are adapted to describe the frequency distribution of component waves. The surface profile of generated wave packets is measured by wave guage array and the effects of dominant spectral parameters governing extreme wave characteristics are investigated. It is found that frequency bandwidth, center frequency, shape of frequency spectrum and directional range play a significant role in the wave focusing. In particular, the directional effect significantly enhances the wave focusing efficiency.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.169-172
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• 2002

When a plane shockwave reflects ken a concave wall, it is focused at a certain location, resulting in extremely high local pressure and temperature. This focusing is due to a nonlinear phenomenon of shock wave. The focusing phenomenon has been extensively applied to many diverse folds of engineering and medical treatment as well. In the current study, the focusing of shock wave over a reflector is numerically investigated using a CFD method. The Harten-Yee total variation diminishing (TVD) scheme is used to solve the unsteady, two-dimensional, compressible, Euler equations. The incident shock wave Mach number $M_{s}\;of\;1.1{\~}l.3$ is applied to the parabolic reflectors with several different depths. Detailed focusing characteristics of the shock wave are investigated in terms of peak pressure, gasdynamic and geometrical foci. The results obtained are compared with the previous experimental results. The results obtained show that the peak pressure of shock wave focusing and its location strongly depend on the magnitude of the incident shock wave and depth of parabolic reflector. It is also found that depending up on the depth of parabolic reflector, the weak shock wave focusing process can classified into three distinct patterns : the reflected shock waves do not intersect each other before and after focusing, the reflected shock waves do not intersect each other before focusing, but intersect after focusing, and the reflected shock waves intersect each other before and after focusing. The predicted Schlieren images represent the measured shock wave focusing with a good accuracy.

• 만화애니메이션 연구
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• 통권46호
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• pp.1-22
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• 2017

정보통신기술의 빠른 발전과 디지털콘텐츠 산업의 확대로 인해 관련 실용학문분야는 교육의 내용과 환경에서 새로운 패러다임이 요구되고 있다. 특히, 디지털콘텐츠 산업의 핵심 분야인 애니메이션 교육은 창의와 융합 그리고 실무교육이 중시되며 교육 내용과 방법에서 많은 개선이 시도되었다. 하지만, 기존 컴퓨터실 형태의 획일적 교육 공간은 애니메이션 교육특성을 충분히 반영하지 못하고 있는 실정이다. 이에, 본 연구는 애니메이션 분야 직무 역량과 애니메이션 프로젝트 제작의 특성이 반영된 효율적인 실습교육 공간 구성을 제안하고자 한다. 이를 위한 연구의 전개는 첫째, 기존의 애니메이션 교육공간의 한계점에 대해 사례를 통해 분석하고, 그 문제점을 도출한다. 또한, Pre-production, Main-production, Post-production의 세 단계로 구성된 애니메이션 제작의 작업적 특성과 순차적 업무에 따른 여섯 개 세부 직무의 역량에 대해 고찰한다. 둘째, 애니메이션 제작공간의 구성을 파악하기 위해 공간구문론을 차용한 6가지 공간 유형에 대해 고찰한다. 셋째, 애니메이션 제작특성, 세부직무역량 요소, 6가지 공간 유형을 분석 툴로 하여, 애니메이션 제작 스튜디오인 Walt Disney의 작업환경과 공간구성에 대해 사례분석을 진행한다. 다섯째, 문헌연구와 사례연구의 결과를 연계적으로 분석하여 애니메이션 프로젝트 진행을 위한 효과적인 교육 공간 구성의 특성을 도출한다. 본 연구를 통해 프로젝트 실무와 직무역량요소의 특성이 반영된 교육 공간 구성을 제시하는데 의의가 있으리라 사료된다. 또한, 본 사례분석을 통해 애니메이션 교육공간 구성을 일반화 하는데 한계가 있으나, 기존과 차별화된 프로젝트 교육 공간구성을 위한 참고자료로 활용가치가 있으리라 기대한다.

• 무역학회지
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• 제45권1호
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• pp.13-29
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• 2020

With the development of the Internet environment, cross-border crowdfunding has emerged as a novel method to attract foreign investors online. Focusing on 324 South Korea-based crowdfunding projects from Kickstarter, which is a representative cross-border crowdfunding platform, this study explores the trends of South Korea-based funding projects and examines the effects of key determinants on crowdfunding outcomes. Regarding the characteristics of crowdfunding projects, analysis results show that the appropriate goal amount and funding period, sufficient updates of project status, and active communication is critical for success. Additionally, from the perspective of project creators, this research finds that creators need to pay greater attention to writing their detailed biographies. Finally, examining the characteristics of project backers, this study shows that attracting project backers from various countries would be desirable rather than focusing on Korean sponsors from the start.

• International journal of advanced smart convergence
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• 제13권2호
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• pp.110-118
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• 2024

This study examines factors influencing nonusers' resistance to the adoption of the metaverse, focusing on propagation mechanisms. It elucidates the role of innovation resistance within the metaverse adoption process. We applied the Innovation Resistance Model in the context of the metaverse and considers three major groups of factors influencing resistance to the metaverse: innovation characteristics (perceived usefulness, compatibility, perceived risk, and complexity), consumer characteristics (personal innovativeness), and propagation mechanisms (mass media, online media, and personal communication). An online survey of college students who do not use the metaverse revealed that perceived usefulness, compatibility, personal innovativeness, and online media were negative predictors of resistance to the metaverse. Conversely, perceived risk, mass media, and personal communication were positive predictors of resistance to the metaverse. Furthermore, innovation resistance was found to play a mediating role in the metaverse adoption process. Drawing upon the findings, we suggested marketing strategies to decrease resistance to the metaverse.