• Korean Journal of Cognitive Science
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• v.16 no.4
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• pp.243-254
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• 2005

Pulfrich effect implies the possibility that motion information is processed by the system that processes depth information, and this possibility by supported by various neurophysiological studies. Although Pulfrich effect is processed by the system that processes binocular disparity, the representative depth information, there has not been a psychophysical research to determine the characteristics of the interaction between Pulfrich effect and binorular disparity using a stimulus containing the two information sources. Present research examined the characteristics of the interacation between Pulfrich effect and binocular disparity by nenuring the depth and rotation direction of a rotating cylinder comprised of random dots under two different conditions: 1) consistent rendition where the Pulfrich effect and binocular disparity depth the depth and rotation direction of the cylinder in a consistent manner 2) inconsistent rendition where they did not. , The perceived depth of the cylinder in the consistent condition was larger than that in disparity/Pulfrich effect only condition. Interestingly, the perceived rotation direction of the cylinder in the inconsistent condition was modulated by the relative strength of the disparity and the Pulfrich effect. These results imply that binocular disparity and Pulfrich effect are processed by a common neurophysiological methanism.

• Quality Improvement in Health Care
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• v.23 no.2
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• pp.11-20
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• 2017

Purpose: The purpose of this study was to determine the effects of rotation direction during curved walking on gait parameters in stroke patients. Methods: A group of thirty subjects with stroke (Berg Balance Scale score${\geq}41$ were fifteen, Berg Balance Scale score${\leq}40$ were fifteen) were enrolled in this study. Testing indications included two directions for rotation in each subject. These indications were for rotation toward the affected and unaffected side in stroke patients. The gait speed, affected side single support duration, affected side double support duration were recorded. The obtained data were analyzed by using paired t-test and Wilcoxon signed rank test in the group that are below and above 40 points of Berg Balance Scale score. Results: There was significant increase affected side single support duration was turned the affected side in stroke patients that presented a Berg Balance Scale score${\geq}41$ (p<.05). There were significant increase gait speed, affected side single support duration, and significant decrease affected side double support duration while subjects were turned the affected side in stroke patients that presented a Berg Balance Scale score${\leq}40$ (p<.05). Conclusion: This result may be effective to rotate in the paralyzed direction to improve the ability of the paralyzed lower limb to gain weight during gait training for stroke patients with a Berg Balance Scale score<40. Therefore, walking training program for hemiplegic patient needs to be suggested in the direction of turning for suitable balance ability.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.948-951
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• 2007

In order to improve the performance of LCD, chiral dopant is added to liquid crystal mixture. When we decide the rubbing direction, we must consider the rotation direction of liquid crystal molecules by chiral dopant. When the rotation direction of liquid crystal molecules caused by dielectric torque decided by rubbing direction and that decided by chiral dopant are coincided, the performance of LCD would be improved along to our initial cell design intentions.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1994.10a
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• pp.145-151
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• 1994

Welded connections have been designed on basis of allowable stresses, wherein the response to loading is assumed to be totally elastic. This is the vector analysis method, which resolves the stresses determined from the direct stress formula and the torsion formula into a vector combination to obtain a solution. It has been known that this method gives conservative answers and typically a very high factor of safety. An analytical method based on the Instantaneous Center of Rotation has been developed which predicts the ultimate strength of an eccentically loaded fillet welded connection. The method of Instantaneous Center of Rotation results in weld resistance capacities greater than the vector analysis method, by recognizing the variation in fillet weld strength with respect to the direction of the applied loading and actual load-deformation response of elemental fillet welds. The procedure of numerical analysis is iterative and complex. The relations between vector analysis method and the method of Instantaneous Center of Rotation on eccentrical distance subjected to variation of load direction are presented in this paper. Considering of the effects on configuration of weld groups, the method of Instantaneous Center of Rotation are provided a more exact results of the numerical analysis.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.10a
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• pp.33-43
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• 1994

A series of tensile tests have been performed to investigate the hardening behavior of rolled steel sheets. Tensile tests consist of three stages. At the 1st stage, full size tensile specimens were prestrained in the direction of rolling, then mid-sized tensile specimens were cut from the gauge sections of the full size specimens at angles to the rolling direction. At the 2nd stage, mid-sized specimens were prestrained by predetermined magnitudes of strains and miniature tensile specimens were prepared from each of the mid-sized specimens at every 10 degrees. At the final stage, from tests on miniature tensile specimens the hardening behavior of the prestrained sheets has been investigated. According to the experimental results, orthotropic symmetry is reserved during tensile elongation, and one of the orthotropy axes is continuously rotated to specimen axis. Existing theories seem to fail to explain the rotation of orthotropy axis. A new phenomenological model is proposed to explain the strain induced rotation of orthotropy axes.

• Korean Journal of Applied Biomechanics
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• v.20 no.3
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• pp.293-301
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• 2010

The purpose of this study was to investigate the kinematic difference between skilled and less skilled group for the forward walk at dance sports rumba. Six female players(skilled group: 3, less skilled group: 3) were participated as the subjects. To obtain the three-dimensional location coordinates in the joints and segments, it shot with 100Hz/s using 8 video cameras. Step length, shoulder rotation angle, orientation angle and angular velocity of pelvis were analyzed for each trail. The skilled group showed a bigger movement than the less skilled group at the shoulder rotation angle and ROM. The skilled group showed a bigger movement than the less skilled group at the up/down obliquity and internal/external rotation movement for pelvis. And the skilled group showed a bigger movement than the less skilled group at Maximum angle (down obliquity) of P2 and Maximum angle (up obliquity) of P3 to pelvis ROM. The skilled group showed a faster angular velocity than the less skilled group at P2 (+ direction, posterior) of anterior & posterior tilt, P2 & P3 (- direction, up) of up & down obliquity, and P2 (+ direction, external) of internal & external rotation.

• Journal of Korean Ophthalmic Optics Society
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• v.18 no.4
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• pp.441-447
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• 2013

Purpose: The present study was conducted to investigate the axial rotations of toric soft lens during the change of lens wearer's posture, and the relationship between its rotation and corneal astigmatism. Methods: The amount, direction, and speed of toric soft contact lens rotation were measured for 42 eyes (aged 20s) with the rule astigmatism in the straight and lying postures, and it compared between their changes according to corneal astigmatism. Results: There was no significant difference in the axial rotation of lens for the astigmatism prescription between the straight and lying postures. However, the rotation angle was significantly different according to the posture of lens wearer. Rotating directions in straight posture were nasal direction for 20 eyes and temporal direction for 22 eyes. In lying posture, lenses of most wearers were rotated to a direction of lying posture, and the initial rotating speed was very fast in initial wearing for -0.75 D toric lenses, but consistency for -1.25 D toric lenses. The rotation angle in lying posture showed significantly different according to the amount of corneal astigmatism, the lens speed was also significantly different according to the wearing time but not the amount of corneal astigmatism. Conclusions: The axial rotation of toric soft lens was different by the lens wearer's posture and its amount was the greater with the higher degree of corneal astigmatism. Thus, these factors should be considered for the development of toric lens design.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.83-86
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• 2002

Numerical simulations are conducted for laminar flow past a sphere rotating In the transverse direction, in order to investigate the effect of the rotation on the characteristics of flow over a sphere. The Reynolds numbers considered are Re=100, 250 and 300 based on the free-stream velocity and the sphere diameter, and the rotational speeds are in the range of $0{\leq}{\omega}{\leq}1$, where ${\omega}^{\ast}$ is the maximum velocity on the sphere surface normalized by the free-stream velocity. At ${\omega}^{\ast}=0$ (without rotation), the flow past the sphere experiences steady axisymmeoy, steady planar-symmetry and unsteady planar-symmetry, respectively, at Re=100, 250 and 300. However, with rotation, the flow becomes planar-symmetric for all the cases investigated and the symmetry plane is orthogonal to the axis of the rotation. The flow is also steady or unsteady depending on both the Reynolds number and the rotational speed, and the vortical structures behind the sphere are significantly modified by the rotation. For example, at Re=300, hairpin vortices completely disappear in the wake at ${\omega}^{\ast}=0.4\;and\;0.6$, and at ${\omega}^{\ast}=1$ vortical structures of a high frequency are newly generated due to the shear layer instability. It is also shown that with increasing rotational speed, the time-averaged drag and lift coefficients increase monotonically.

• Journal of Korean Ophthalmic Optics Society
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• v.20 no.4
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• pp.445-454
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• 2015

Purpose: The present study was aimed to investigate the effect of tear volume on a change of axial rotation according to wearing time of toric soft contact lens and gaze directions. Method: Toric soft contact lenses with double thin zone design applied on 62 eyes. Then, changes in non invasive tear film break-up time and the rotational direction/amount of lens when changing gaze direction were respectively measured after 15 minutes and 6 hours of lens wear. Results: Lens rotation to temporal direction was more found when changing gaze direction after lens wear. However, its rotation was varied according to wearing time and the subjects' tear volume. Furthermore, the frequency of lens rotation to temporal direction was higher in dry eyes compared with normal eyes at nearly all gaze directions after 15 minutes and 6 hour of lens wear. The rotational amount of lens was generally greater in dry eyes after 15 minutes of lens wear. However, its difference between normal eyes and dry eyes was not great after 6 hours of lens wear. Conclusion: The present study revealed that axial rotation of toric soft contact lens was varied according to the wearer's tear volume and lens rotational patterns at the initial, and extending periods of lens wear were different. The change in rotational pattern of toric soft contact lens from these results means the possibility of visual change after extending lens wear, and the identification of its correlation with tear volume suggests the necessity of considering factors for choosing appropriate toric soft contact lens.

• Human Ecology Research
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• v.55 no.2
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• pp.125-140
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• 2017

This study composed spatial cognition tasks within the system of geometric area to study children's spatial cognition development systematically. It surveyed children's execution of direction, rotation, symmetry, conjugation, and part/whole cognition tasks. A spatial geometry cognition task set (consisting of total 27 sub-tasks) was presented to 60 children (20 each in groups of 3-, 4-, and 5-year-old) in order to confirm how children's execution of spatial geometry cognition changed depending on children's age and sex as well as if the execution of the spatial geometry cognition showed a difference after each task area. As a result, the execution of the whole direction task and the part/whole task gradually increased between age 3 and age 5. The execution of the whole rotation task, whole symmetry task, and whole conjugation task rapidly increased between age 3 and age 4. Significant sexual difference did not appear in the execution of spatial geometry cognition tasks. The execution of the conjugation and part/whole task was high in each task area, and the execution of the direction, rotation, and symmetry task was relatively low. In addition, the difference of task execution appeared in the sub-tasks of direction, symmetry, and conjugation areas. This result suggests the theoretical discussion possibility of children's spatial geometry cognition development. In addition, the empirical results of this study can be applied to child education plans and activity compositions appropriate for child development.