• 한국운동역학회지
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• 제20권2호
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• pp.117-127
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• 2010

The axes of upper forearm coordinate system have been considered as principal axis of each segment which was component of elbow joint. The purpose of this study was to verify whether the mean direction(principal axis) of instantaneous axes of rotation for pure flexion/extension motion coincided with the flexion/extension axis of upper forearm coordinate system. The same procedure was done for pronation/supination motion. Furthermore, it was tested indirectly that there was an interaction effect between the two rotational motions. The results showed that most segment coordinate axes statistically were not consistent with the mean directions of flexion/extension and pronation/supination axes of rotation. From the results, it would be concluded that the ISB coordinate systems was proved to be a little valid for human movement analysis. There also was an effect of pronation/supination angles on flexion/extension motion.

• 천문학회보
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• 제40권2호
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• pp.30.3-31
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• 2015

We present a kinematic analysis of 172 likely member galaxies of the Ursa Major Cluster. In order to understand the dynamical state of the cluster, we investigate the correlation of the cluster morphology with rotation, the velocity dispersion profile, and the rotation amplitude parallel to the global rotation direction. Both the minor axis and the rotation are very well-aligned with the global rotation axis in the outer region at half radius (> 0.5 $R_{max}$), but not in the inner region. The cluster exhibits low velocity dispersion and rotation amplitude profiles in the inner region, but higher in the outer. Both profiles exhibit outwardly increasing trends, suggesting an inside-out transfer of angular momentum of dark matter via violent relaxation, as revealed by a recent off-axis major-merging simulation. From Dressler-Schectman plots in the plane of galactic positions, and velocity versus position angle of galaxy, we are able to divide the Ursa Major Cluster into two substructures: Ursa Major South (UMS) and Ursa Major North (UMN). We derive a mass of $3.2{\times}10^{14}M_{\odot}$ for the cluster through the two-body analysis by the timing argument with the distance information (37 for UMN and 36 for UMS) and the spin parameter of ${\lambda}=0.049$. The two substructures appear to have passed each other 4.4 Gyr ago and are moving away to the maximum separation.

• 한국초전도ㆍ저온공학회논문지
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• 제19권2호
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• pp.9-13
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• 2017

This study presents a simple method to control the seed orientation which leads to the various growth characteristics of a single grain REBCO (RE: rare-earth elements) bulk superconductors. Seed orientation was varied systematically from c-axis to a-axis with every 30 degree rotation around b-axis. Orientations of a REBCO single grain was successfully controlled by placing the seed with various angles on the prismatic indent prepared on the surface of REBCO powder compacts. Growth pattern was changed from cubic to rectangular when the seed orientation normal to compact surface was varied from c-axis to a-axis. Macroscopic shape change has been explained by the variation of the wetting angle of un-reacted melt depending on the interface energy between $YBa_2Cu_3O_{7-y}$ (Y123) grain and melt. Higher magnetic levitation force was obtained for the specimen prepared using tilted seed with an angle of 30 degree rotation around b-axis.

• 대한치과교정학회지
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• 제15권1호
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• pp.123-140
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• 1985

Variation in the facial pattern and effect of the rotational jaw growth on the facial proportion were studied in serial cephalometric radiographs of 40 Korean children (25 boys, 15 girls) ranging in age from 6 to 13 years. According to Y-axis (N-S-Gn) growth change during the 7 years of period, the subject who had exhibited 'wave-like' manner of Y-axis growth change within ${\pm}\;2^{\circ}$ was classified to the Parallelwise group and the subject who had exhibited Y-axis increase more than $+2^{\circ}$ was classified to the Clockwise rotation group and the subject who had exhibited Y-axis decrease more than $-2^{\circ}$ was classified to the Counterclockwise rotation group. For the comparison of each group, a total of 22 morphologic variables were employed and the data were analyzed by means of computer morphometrics and statistical methods. On the basis of the finding of this study, the following trends were established. 1. The Parallelwise group was $75\%$, the Clockwise rotation group was $12.5\%$ and the Counter-clockwise rotation group was $12.5\%$. 2. The growth pattern of cranial base was related to the rotation of mandible. 9. Maxillary prognathism was occured in the Counterclockwise rotation group and the rotation of palatal plane was occured in the Clockwise rotation group. 4. Mandibular prognathism was occured in the Parallelwise and the Counterclockwise rotation groups, especially in the Counterclockwise rotation group. 5. The degree of maxillo-mandibular divergency was constant in the Clockwise rotation group but decreased in the Counterclockwise rotation and the Parallelwise groups, especially in the Counterclockwise group. 6. There were no differences in the size of the anterior upper facial height (N-ANS) and the posterior lower facial height ((Go-Me)-PNS) but there were differences in the size of the anterior lower facial height (ANS-Me) and the posterior upper facial height ((S-N)-PNS) between each group. 7. The growth increment and the size of the facial depth was not related to the growth pattern of the face but the growth increment and the size of the facial height was related to the growth pattern of the face. 8. Proportional change due to the facial growth rotation was concentrated in the anterior lower face. 9. The most apparent difference between each group was happened in the size of the posterior cranial base (S-Ba) and the facial length (S-Gn).

• 한국안광학회지
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• 제10권4호
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• pp.255-259
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• 2005

난시 교정용 콘택트렌즈 착용 시 렌즈의 축 방향을 정확하게 하지 않을 경우이거나, 착용 후 순목 시 안검 등에 의해 콘택트렌즈가 회전할 경우가 있다. 이러한 현상이 있을 경우 완전교정상태가 잘못 교정된 상태로 되기 때문에 안정피로를 유발하여 시력의 저하를 가져올 수 있다. 이런 이유로 콘택트렌즈가 어느 정도 회전했는지의 파악이 필요하다. 콘택트렌즈가 회전했다면 착용 후 굴절검사에서 잔류 난시가 검출될 것이다. 이것을 이용해서 우리는 콘택트렌즈의 회전량을 계산하는 프로그램을 개발하였다.

• 한국안광학회지
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• 제11권2호
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• pp.77-83
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• 2006

본 연구에서는 프리즘 처방을 위해 편심된 안경렌즈의 산각위치에 따른 수차와 경사각에 따른 수차를 계산하였다. 프리즘 처방을 위해서 일반적으로 일반 렌즈를 편심시켜 만든다. 광축과 주시축 사이의 차이는 수차를 발생시키기 때문에, 이런 경우 산각의 위치가 중요하다. 우리는 계산을 통하여 산각 회전 띠의 축이 (+)렌즈의 전면 곡률 중심을 지나는 것이 후면곡률 중심을 지나는 것보다 비점수차가 적게 발생하였고, 산각 회전 띠의 (-) 렌즈의 후면곡률 중심을 지나는 것이 전면보다 비점수차가 적게 발생한다는 결과를 얻었다. 렌즈의 굴절력이 클수록 비점수차가 작았다.

• 천문학회보
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• 제43권1호
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• pp.44.3-45
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• 2018

Magnetic fields affect star formation in a broad range of scales from parsec to hundreds au. In particular, interferometric observations and ideal magneto-hydrodynamic (MHD) simulations have reported that formation of a rotation-supported disk at the earliest young stellar objects (YSOs) is largely suppressed by magnetic fields aligned to the rotational axis of YSOs: magnetic braking. Our recent ALMA observations toward L1448 IRS 2, which has a rotation detected and its magnetic fields aligned to the rotation axis (poloidal fields) in ~500 au scales, show that the fields switch to toroidal at the center in ~100 au scales. This result suggests that magnetic braking may not be so catastrophic for early disk formation even in YSOs with magnetic fields aligned to the rotational axis.

• Current Applied Physics
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• 제18권11호
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• pp.1261-1267
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• 2018

In this paper, an off-axis digital holographic microscopy compensated with self-hologram rotation is presented. The process is implemented via subtracting the unwrapped phase maps of the off-axis parabolic hologram and its rotation $180^{\circ}$ to eliminate the tilt induced by the angle between the spherical object wave O and the plane reference wave R. Merit of the proposed method is that it can be done without prior knowledge of physical parameters and hence can reconstruct a parabolic hologram of $1024{\times}768$ pixels within tens of milliseconds since it doesn't require a digital reference wave. The method is applied to characterize rough gold bumps and the obtained results were compared with those extracted from the conventional reconstruction method. The comparison showed that the proposed method can characterize rough surfaces with excellent contrast and in realtime. Merit of the proposed method is that it can be used for monitoring smaller biological cells and micro-fluidic devices.

• Journal of Information Processing Systems
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• 제16권1호
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• pp.120-131
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• 2020

In order to solve the problem of point clouds coordinate conversion of non-directional scanners, this paper proposes a basic Rodrigues rotation method. Specifically, we convert the 6 degree-of-freedom (6-DOF) rotation and translation matrix into the uniaxial rotation matrix, and establish the equation of objective vector conversion based on the basic Rodrigues rotation scheme. We demonstrate the applicability of the new method by using a bar-shaped emboss point clouds as experimental input, the three-axis error and three-term error as validate indicators. The results suggest that the new method does not need linearization and is suitable for optional rotation angle. Meanwhile, the new method achieves the seamless splicing of point clouds. Furthermore, the coordinate conversion scheme proposed in this paper performs superiority by comparing with the iterative closest point (ICP) conversion method. Therefore, the basic Rodrigues rotation method is not only regarded as a suitable tool to achieve the conversion of point clouds, but also provides certain reference and guidance for similar projects.

• 한국안광학회지
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• 제20권2호
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• pp.133-140
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• 2015

목적: 본 연구에서는 축 안정화 디자인이 상이한 두 토릭소프트콘택트렌즈의 회전축과 회전량이 자세와 응시방향에 따라 달라지는 지를 알아보았다. 방법: 20~30대 52안을 대상으로, Lo-Torque$^{TM}$디자인 및 ASD 디자인(accelerated stabilized design) 토릭소프트콘택트렌즈를 피팅한 후 정면을 포함한 5가지 응시방향과 누운 자세에서의 회전량을 측정하였다. 결과: 정자세에서 정면 및 수직방향 응시 시 Lo-Torque$^{TM}$ 디자인 렌즈는 코쪽, ASD 디자인 렌즈는 귀쪽으로 회전하는 비율이 높은 것으로 나타났다. 수평방향 응시시에는 두 렌즈 모두 응시방향과 반대로 축회전이 일어났다. 위쪽을 응시할 때의 회전량이 가장 작았으며 코쪽을 응시할 때의 회전량이 가장 많았다. $5^{\circ}$ 이내의 회전량을 보인 경우는 정면과 수직방향을 응시할 때의 Lo-Torque$^{TM}$ 디자인 렌즈에서 더 많았으며, 수평방향 응시 시에는 ASD 디자인 렌즈에서 더 많았다. 또한, 누운 직후에는 Lo-Torque$^{TM}$ 디자인 렌즈의 회전량이 더 적었으나 1분 후에는 ASD 디자인 렌즈의 회전량이 더 적었다. 결론: 본 연구에서는 토릭소프트콘택트렌즈 착용 후 응시방향 및 자세에 의해 유발되는 축회전이 축 안정화 디자인에 따라 달라짐을 확인하였다.