• The Bulletin of The Korean Astronomical Society
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• v.37 no.1
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• pp.36.1-36.1
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• 2012

Recent wide and deep surveys allow us to investigate the large scale structure of the Universe at high redshift. We present studies of the clustering of high redshift galaxies, using reprocessed UKIDSS DXS catalogue. We measure the angular correlation function of high redshift galaxies which is Extremely Red Objects (EROs). Firstly we found that their angular correlation functions can be described by a broken power-law. We also found that red or bright samples are more strongly clustered than those having the opposite characteristics, and that old, passive EROs are found to be more clustered than dustry, star-forming EROs. Additionally the average halo mass and other properties were estimated using the halo model. Finally the observed clustering of EROs was compared with predictions from the cosmological simulation.

• Korean Journal of Applied Biomechanics
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• v.30 no.3
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• pp.205-215
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• 2020

Objective: The purpose of this study was to investigate the relative angles and cross-correlation between body segments and ski among four alpine ski turning techniques. Method: 19 alpine ski instructors participated in this study. Each skier asked to perform 4- types of turning technique, classified by radius and level. 8 inertial measurement units were used to measure orientation angle of segment and ski on the anteroposterior and vertical axis. Results: Significant differences were found between types of turning in the segments-ski relative angle on the anteroposterior and vertical axis (p<.05). Although, cross-correlation showed a high correlation between angles of segment and ski, there were significant differences between types of turning. Conclusion: Based on our results, the relative movement and timing between each segment and ski is different according to the turning techniques, so the training methods should be applied differently.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.13 no.2
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• pp.92-98
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• 2003

A rate gyroscope has been used popularly to measure the angular motion of a given vehicle using a symmetric rotor spinning rapidly about its symmetry axis. Since the rapid rotation is required in this type of gyroscope, the motor has been used to make the rotor spin, so that it results in a heavy configuration. The toning-fork gyroscope has been developed to avoid this problem, which utilizes a Coriolis coupling term and vibration about one axis. Due to the Coriolis effect, the vibration of one axis is transferred to other axis when the angular motion along the vibrating axis is given to the system. The concept of a tuning-fork gyroscope was recently realized using MEMS techniques. However, the dynamic characteristics of the tuning-fork gyroscope has not been discussed in detail. In this study. we derived the equations of motion for the tuning-fork type gyroscope using the energy approach and investigated the dynamic characteristics by means of numerical analysis.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.247-252
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• 2002

A rate gyroscope has been used popularly to measure the angular motion of a given vehicle using a symmetric rotor spinning rapidly about its symmetry axis. Since the rapid rotation is required in this type of gyroscope, the motor has been used to make the rotor spin, so that it results in a heavy configuration. The tuning-fork gyroscope has been developed to avoid this problem, which utilizes a coriolis coupling term and vibration about one axis. Because of the coriolis effect, the vibration of one axis is transferred to other axis when the angular motion along the vibrating axis is given to the system. The concept of a tuning-fork gyroscope was recently realized using MEMS techniques. However, the dynamic characteristics of the tuning-fork gyroscope has not been discussed in detail. In this study, we derived the equations of motion for the tuning-fork type gyroscope using the energy approach and investigated the dynamic characteristics by means of numerical analysis.

• Journal of Educational Research in Mathematics
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• v.18 no.2
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• pp.263-281
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• 2008

This study is to provide a base for discussions on teaching and teaming of radian through a theoretical analysis of it. Radian possesses two-fold comprehensive properties of measurement as a magnitude and a pure number. As a magnitude of an angle, it has some theoretical advantages in mathematics and in physics, in spite of its non-superiority to other angular measures in practical sense. As a pure number, it has some advantages in that it simplifies theoretical developments of trigonometric functions and justifies omitting the unit in the calculations and final expressions in physics. Radian should be taught and learnt with an appreciation of the advantages of the two-fold properties. Activities to measure angles from various viewpoints may be helpful for this. Students' awareness of the advantages of radian needs to be stimulated and deepened repeatedly as related content appears.

• PNF and Movement
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• v.16 no.2
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• pp.169-178
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• 2018

Purpose: This study aimed to investigate the effect of angular joint mobilization (AJM) on the shoulder pain, range of motion, and functional improvement in a patient with shoulder adhesive capsulitis. Methods: The patient diagnosed with right shoulder adhesive capsulitis by an orthopedic surgeon was a 60-year-old male, right hand/arm dominant, with a height of 175 cm and weight of 75 kg. The patient received 12 sessions of AJM once or twice per week for eight weeks. AJM was applied for 5 min each of flexion, abduction, external rotation, internal rotation, for a total of 20 min per session. The visual analog scale, the goniometer, and the Oxford shoulder score were used to measure pain, range of motion, and shoulder pain & disability index, respectively. Results: After all the treatments, the pain decreased from 6 to 2 points. The range of motion increased in flexion by $54.3^{\circ}$ from $125^{\circ}$ to $179.3^{\circ}$, abduction by $38^{\circ}$ from $140^{\circ}$ to $178^{\circ}$, external rotation by $54.4^{\circ}$ from $30.3^{\circ}$ to $84.7^{\circ}$, and internal rotation by $25^{\circ}$ from $45^{\circ}$ to $70^{\circ}$. The shoulder disability index decreased from 33 points to 17 points. Conclusion: This study found that AJM has a positive effect on the improvement of shoulder pain, range of motion, and function in a patient with shoulder adhesive capsulitis. Further studies on AJM are needed in the future.

• Korean Journal of Applied Biomechanics
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• v.34 no.2
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• pp.45-52
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• 2024

Objective: The purpose of this study was to measure the morphological characteristics of the foot and biomechanical variables of the lower extremity joints during vertical jump and investigate the relationship between foot morphology and biomechanics of vertical jump. Method: 24 men in their 20s (age: 22.42 ± 1.41 yrs, height: 173.37 ± 4.61 cm, weight: 72.02 ± 6.21 kg, foot length: 251.70 ± 8.68 mm) participated in the study. Morphological characteristics of the foot included the length of the first toe, the length of the second toe, and the horizontal length from the center of ankle joint to the achilles tendon (Plantar Flexion Moment Arm [PFMA]). Biomechanical variables were measured for plantar flexor strength of the ankle joint and peak angular velocity, moment, and power of the lower extremity joint during vertical jump. Results: There was a significant correlation between the length of the first toe and plantar flexion strength at 30°/s [r=.440, p=.016], the angular velocity of the metatarsophalangeal [MTP] joint [r=-.369, p=.038] while significant correlations between PFMA and the angular velocities of the knee joint [r=.369, p=.038] and ankle joint [r=.420, p=.021] were found. There were also significant correlations between the length of the first toe and the maximum moment of the hip joint [r=.379, p=.034], and the length of the second toe and the power of the hip joint [r=-.391, p=.029]. Finally, significant correlations between PFMA and the power of the ankle joint [r=.424, p=.019] and MTP joint [r=.367, p=.039] were found. Conclusion: Based on the results of this study, the length of the toe and PFMA would be related to the function of the lower extremity joint. Therefore, this should be considered when designing the functional structure of a shoe. Furthermore, this relationship can be applied to intensive training for the plantar flexors and toe flexors to improve power in athletic performance.

• Journal of KSNVE
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• v.11 no.1
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• pp.132-140
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• 2001

The vibratory gyroscope can effectively measure the angular velocity as the oscillating and position-sensing mode are exactly tuned. The veering Phenomenon impedes the exact tuning, which is caused by the mode coupling of two modes. In this paper, the gyroscope's structure with two frames is introduced to minimize the veering phenomenon that destabilizes the tuning process of oscillating and position-sensing mode. Experimental results show that the Proposed structure can achieve the mode intersection without veering phenomenon.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.689-692
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• 1998

Matching two images is an essential step for many computer vision applications. A new approach to the scale and rotation invariant scene matching is presented. A set of andidate parameters are hypthesized by mapping the angular difference and a new distance measure to the hough space and by detecting maximally consistent points. The proposed method is shown to be much faster than the conventinal one where the relaxation process is repeated until convergence, while providing robust matching performance, without a priori information on the geometrical transformation parameters.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.11
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• pp.160-166
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• 2002

In this paper, data acquisition and analysis of a measuring machine for marine engine's cams is discussed. A rotary encoder and linear scale of the machine to measure angular and linear displacement respectively are interfaced to the PC via encoder board with 2 channels. The design and measuring data are interpolated by cubic spline curves to compute the precision error which is defined by the maximum and minimum distances between two curves. The minimum zone fit of ISO is employed to evaluate the geometric deviation. The developed system takes only 5 minutes to measure and analyze while the CMM takes over 1 hours even with a skilled operator.