• Journal of Convergence for Information Technology
• /
• v.11 no.10
• /
• pp.20-26
• /
• 2021

In this paper, we studied the rotation angle estimation methods required for image alignment in an image recognition environment. In particular, a rotation angle estimation method applicable to a low specification embedded-based environment was proposed and compared with the existing method using complex moment. The proposed method estimates the rotation angle through similarity mathcing of the 1D projection profile along the radial axis after converting an image into polar coordinates. In addition, it is also possible to select a method of using vector sum of the projection profile, which more simplifies the calculation. Through experiments conducted on binary pattern images and gray-scale images, it was shown that the estimation error of the proposed method is not significantly different from that of complex moment-based method and requires less computation and system resources. For future expansion, a study on how to match the rotation center in gray-scale images will be needed.

• Korean Journal of Applied Biomechanics
• /
• v.25 no.3
• /
• pp.293-300
• /
• 2015

Objective : The purpose of this study was to compare the kinematic data of the horizontal rotation movements of shoulder, hip, knee during two-handed backhand drive stroke according to two different ball directions. Methods : The kinematic variables were analyzed such as the joint angles of the lower body, horizontal rotation angles of the shoulder, hip, inter-knee segment, body twist angle and difference in angle of forward swing. Two-handed backhand drive stroke was analyzed through a three-dimensional motion analysis. The collected data were analyzed by a paired t-test, and the statistical significant value was set at ${\alpha}=.05$. Results : The findings of this study were as follows; First, there was no difference in the total angles of lower limb joints from the forward swing position to impact posterior. Second, there was no difference in the horizontal rotation angles of E1 shoulder, hip, and E2 shoulder but the horizontal rotation angles of E1 knee, E2 hip, knee, E3, and E4 shoulder, hip, and knee were different in all events. Third, there was no difference in the body twist angle of the maximum horizontal rotation. In addition, there was no difference in the angle of the body twist by the ball direction in the shoulder-hip, the hip-knee and the shoulder-knee. Conclusion : Horizontal rotation angle determines ball directions.

• Journal of Korean Physical Therapy Science
• /
• v.30 no.3
• /
• pp.14-22
• /
• 2023

Background: This study was to investigate the relationship between scapular downward rotation ratio (SDRR), lower trapezius (LT) muscle, and rounded shoulder angle (RSA) on each side in subjects with scapular downward rotation syndrome (SDRS). Design: Cross-sectional Study Methods: Fifteen subjects have participated in this study. The RSA and SDRR were assessed using a tape measure in standing posture. The RSA was computed by the angle made by two lines: one was the distance between the root of the scapula and the acromion, and the other was the distance between the acromion and the horizontal line in the root of the scapula. The SDRR was computed by two horizontal lines: one was the distance between the mid-line and root of the scapula, and the other was the distance between the mid-line and inferior angle of the scapula. LT muscle strength was performed in a prone position by the hand-held dynamometer. Results: There was a positive correlation between SDRR and LT strength in the less affected sides (r=.59; p=.02), however, there was no correlation between RSA and LT strength in the more affected sides (p>.05).

• Proceedings of the Korean Geotechical Society Conference
• /
• 2001.03a
• /
• pp.161-166
• /
• 2001

Overconsolidated clays have a different stress history according to the deposit environment. The stress history is classified into (i) rotation angle of stress path, (ii) overconsolidation ratio, and (iii) magnitude of length of recent stress path. Stress-strain behaviour of overconsolidated clays strongly depends on these stress history. In this study a series of drained stress path tests were carried out. Test results indicated that stress-strain behaviour of overconsolidated clay(focused on strain rate) depends on OCR and length of recent stress path, especially rotation angle.

• PNF and Movement
• /
• v.18 no.2
• /
• pp.223-231
• /
• 2020

Purpose: The purpose of the study was to compare the effects of different methods of pelvic control on abdominal muscle activity and lumbopelvic rotation angle during active straight leg raising (ASLR) in patients with chronic back pain. Methods: The study participants were patients with low back pain (n = 30). They were instructed to perform ASLR with pelvic control, ASLR with pelvic belt, and ASLR only. Surface electromyography data were collected from the ipsilateral rectus femoris (IRF), ipsilateral internal oblique (IIO), contralateral external oblique (CEO), and ipsilateral rectus abdominal (IRA) muscles, and lumbopelvic rotation angle was measured using a motion analysis device. Results: Activation of all abdominal muscles was greater in the ASLR with pelvic control group than in the ASLR with pelvic belt and ASLR groups. The lumbopelvic rotation angle was lower in the ASLR with pelvic control group than in the other two groups (p < 0.05). Conclusion: These results suggest that ALSR with pelvic control is an effective means of increasing abdominal muscle activity and reducing unwanted lumbopelvic rotation in patients with chronic low back pain. Controlling the pelvis using the opposite leg is an effective form of ASLR exercise for patients with chronic low back pain.

• Journal of Magnetics
• /
• v.22 no.1
• /
• pp.7-13
• /
• 2017

The magnetoresistance (MR) properties of antiferromagnetic (AFM) IrMn based giant magnetoresistance-spin valve (GMR-SV) was investigated in view point of the artificial rotation effect of ferromagnetic (FM) layer in the plane induced by an applied field during the post annealing temperature. The MR curves measured with an azimuthal angle region of ${\phi}=0^{\circ}-360^{\circ}$ are depended on the annealing temperature and the magnetization easy axis of two free NiFe layers and two pinned NiFe layers in dual-type GMR-SV film. Especially, the annealing temperature and sample rotation angle(${\theta}$ ) maintained to the magnetic sensitivity (MS) of 1.4 %/Oe with an isotropic region angle of $110^{\circ}$ are $100^{\circ}C$ and $90^{\circ}$, respectively.

• Proceedings of the KIEE Conference
• /
• 1999.07g
• /
• pp.2821-2823
• /
• 1999

In this paper we proposed an algorithm for rotation-invariant pattern recognition and rotated angle estimation between two patterns by employing selective template matching. Generally template matching has been used in determining the location of pattern but template matching requires a number of calculating correlation. To reduce the number of correlation we used steady-state genetic algorithm which is effective in optimization problem. We apply this method to distinguish specific pattern from similar coin patterns and estimate rotated angle between patterns. Our result leads us to the conclusion that proposed method performed faster than classical template matching

• Korean Journal of Applied Biomechanics
• /
• v.23 no.3
• /
• pp.271-278
• /
• 2013

The purpose of this study was to determine the effect of Pilates Reformer training on gait improvement of subjects with asymmetric pelvic rotation. The seven subjects with greater pelvic rotation in right swing were assessed twice, 4 weeks apart, during which there was submitted to a Pilates Reformer training (three 40 min session per week). The kinematic data consisted of pelvic rotation and flexion angle of hip and knee joint was measured during gait. In comparison between both leg swings, max, min and range values of pelvic rotation was not significantly difference. After training, range of pelvic rotation in right swing was significantly decreased, but in left swing was not. In comparison between both leg swings, the values of max of hip and knee joint angle was significantly difference. After training, max values of angle of knee joint in right swing was significantly increased, but in left swing was not. The result of this study revealed that Pilates Reformer training was effective in improving gait to symmetric pelvic rotation.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.58 no.3
• /
• pp.605-613
• /
• 2009

In this paper, we studied for the real-time azimuthal measurement of HMD (Head Mounted Display) to control the tele-operated vision system on the mobile robot. In the preexistence tele-operated vision system, a joystick was used to control the pan-tilt unit of the remote camera system. To give the sense of presence to the tele-operator, we used a HMD to display the remote scene, measured the rotation angle of the HMD on a real time basis, and transmitted the measured rotation angles to the mobile robot controller to synchronize the pan-tilt angles of remote camera with the HMD. In this paper, we suggest an algorithm for the real-time estimation of the HMD rotation angles using feature points extraction from pc-camera image. The simple experiment is conducted to demonstrate the feasibility.

• Proceedings of the IEEK Conference
• /
• 2009.05a
• /
• pp.360-362
• /
• 2009

In this paper, we studied for the real-time azimuthal measurement of HMD(Head Mounted Display) using the feature points detection to control the tele-operated vision system on the mobile robot. To give the sense of presence to the tele-operator, we used a HMD to display the remote scene, measured the rotation angle of the HMD on a real time basis, and transmitted the measured rotation angles to the mobile robot controller to synchronize the pan-tilt angles of remote camera with the HMD. In this paper, we suggest an algorithm for the real-time estimation of the HMD rotation angles using feature points extraction from pc-camera image.