• Journal of Advanced Marine Engineering and Technology
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• v.36 no.4
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• pp.512-519
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• 2012

This paper proposes a 3-D pose (positions and orientations) estimation system based on the recognition of circular ring patterns. To deal with monocular vision-based pose estimation problem, we specially design a circular ring pattern that has a simplicity merit in view of object recognition. A pose estimation procedure is described in detail, which utilizes the geometric transformation of a circular ring pattern in 2-D perspective projection space. The proposed method is evaluated through the analysis of accuracy and precision with respect to 3-D pose estimation of a quadrotor-type vehicle in 3-D space.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.8
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• pp.766-773
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• 2011

The inclination attitude of the Ground-Based Radar can be measured by the accelerometer due to its static operation environment, but the measurement error is generated from the angular acceleration of the accelerometer, which is created in mechanical oscillation by the dynamic environment, like the wind, gust, rotating antenna, etc. In this paper, the technique of reducing the measurement error of the attitude by the dynamic attitude is proposed and the result of the simulation and the analysis of tracking error by the attitude error are presented.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.4 no.4
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• pp.231-235
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• 2011

In these day, the number of people who have an abnormal posture caused by bad habit are increasing. Therefore, people suffer various disease and symptoms. For correcting the posture to cure, we need continuous monitor, expenditure of time and money. In this study, we develop a posture correcting aid system in other to monitor a posture continuously and leads to pose correctly and records postural variation which are attached to the neck and the waist. The devised system showed good potential for the correct posture guide and a cure of postural defect.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.2
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• pp.469-478
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• 2010

This paper proposes the effective shape descriptor for 3D foot pose estimation. To reduce processing time, silhouette-based foot image database is built and meta information which involves the 3D pose of the foot is appended to the database. And we proposed a modified Centroid Contour Distance whose size of the feature space is small and performance of pose estimation is better than the others. In order to analyze performance of the descriptor, we evaluate time and spatial complexity with retrieval accuracy, and then compare with the previous methods. Experimental results show that the proposed descriptor is more effective than the previous methods on feature extraction time and pose estimation accuracy.

• Proceedings of the Korea Information Processing Society Conference
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• 2021.11a
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• pp.787-790
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• 2021

본 논문에서는 최신 모션 인식 기술을 활용하여 골프 스윙 비디오에서 사람의 자세를 추정한 후 다양한 원인으로 오검출된 좌표들을 보정하여 자세 추정의 정확도를 높이는 방법을 제안한다. 기존의 사람 자세 추정 모델은 골프 스윙 데이터에서 오검출, 반전, 불안정성, 미검출의 문제를 보여 정확한 자세 추정을 어렵게 했다. 이를 해결하기 위하여 본 연구에서는 자세 추정시 발생하는 이상치 데이터들을 Bi-LSTM 으로 학습하고 골프 스윙의 특징을 고려한 간단한 규칙을 통하여 이상치 데이터를 효과적으로 검출하고 이를 보정하는 방법을 제안한다. 또한 다양한 실험과 분석을 통하여 제안하는 방법이 골프 스윙 모션에서 사람의 자세를 정확히 추정할 수 있음을 보인다.

• The Journal of the Korea Contents Association
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• v.14 no.2
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• pp.430-441
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• 2014

The present study is a descriptive survey to examine the knowledge of and attitudes towards musculoskeletal disorders and the bad postural habits in nursing students and to determine the relationships between the both sides. This study was performed using a structured questionnaire from September 2 through 17, 2013. The questionnaire copies collected from 272 nursing students were analyzed using t-test, one-way ANOVA, Pearson's correlation coefficient. The following are the results: First, the subjects won 2.75, 3.24 and 3.21 among 1 to 5 points in the knowledge of musculoskeletal disorders, the attitudes towards musculoskeletal disorders and the bad postural habits. Among the bad postural habits, they earned higher points in the postures of lying on the back in a sofa, carrying a bag on the shoulder and sitting with legs crossed. Second, significant negative correlations with the knowledge of and attitudes towards musculoskeletal disorders were shown only by the postures of sleeping lying on the side, lifting things with the waist bent at and sitting with hips placed on and no back attached to a chair. The results of this study are expected to be used as basic data to enhance the awareness that nursing students should correct their bad postural habits and to strengthen the knowledge of and attitudes towards musculoskeletal disorders at the time of developing any musculoskeletal health improvement program for nursing students.

• Journal of the Korean Society of Radiology
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• v.5 no.4
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• pp.179-187
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• 2011

This study statistically analyzed the difference of the stability of maintaining a respiratory period shown according to position and use of a device to search the tendency and usefulness of a device. The supine position showed better maintaining respiratory cycles than the prone position. The 85% of subjects who showed bad maintenance pattern of a respiratory cycle were significantly different pattern with using belly board. It could be said that there was a significant correlation between the maintenance of a respiratory cycle and relative index of respirational stability(p=0.044, kappa=0.607). The movement due to respiration was one of important considerations in the radiation therapy on chest, abdomen, and even pelvis. This study could contribute to the high quality radiation therapy by statistic analysis of respiratory signals and its application.

• The Journal of Korean Academy of Sensory Integration
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• v.14 no.2
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• pp.46-57
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• 2016

Objective : The purpose of this study is to prove the effects of exercise intervention on postural control of children with cerebral palsy in Korea by systematic review. Methods : Total 18 studies were selected through Korean research database engine such as DBpia, KISS and RISS for the systematic review in this study. Key words used were 'cerebral palsy', 'postural control' and 'balance' and publication time period was limited only after October 2006 in the research selection. All the selected studies were reviewed in terms of quality level of evidence and methodological quality level, and then the results were analyzed with Patient, Intervention, Comparison, Outcome (PICO). Results : For the level of evidence, it is found that 8 studies show Grade I, 5 studies show Grade III, and 2 studies show Grade V. In terms of Methodological quality, majority of the studies showed 'Fare' level. Majority of target population of the studies was children with spastic diplegia. Most research design of the studies were randomized controlled trials. The results in several suited showed that the postural control exercise used in Korea has positive impact on improvement of motor and balance ability. Conclusion : Impact of the exercise intervention used in Korea for postural control of children with cerebral palsy has been evidenced in this study. It is proposed that further research need to be done considering several types of cerebral palsy.

• Journal of Aerospace System Engineering
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• v.12 no.3
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• pp.45-52
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• 2018

This paper deals with the analysis of the inner-loop algorithm of the Pixhawk which is a representative multi-copter open source. The algorithm is based on flight control-law structure. The inner-loop algorithm of the Pixhawk can be divided into a position controller and an attitude controller. The position controller generates the attitude of the multi-copter to move to the destination The position controller also generates the demand force and moment acting on each actuator. We confirm that the position controller saturates the desired acceleration and speed by using a proper relational expression. The expression can be used in order to prevent the sudden change in the attitude of a multi-copter.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.49 no.4
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• pp.23-35
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• 2012

This paper presents a 3-D pose (position and orientation) estimation method for an elliptic object in 3-D space. It is difficult to resolve the problem of determining 3-D pose parameters with respect to an elliptic feature in 3-D space by interpretation of its projected feature onto an image plane. As an alternative, we propose a two points-based pose estimation algorithm to seek the 3-D information of an elliptic feature. The proposed algorithm determines a homogeneous transformation uniquely for a given correspondence set of an ellipse and two coplanar points that are defined on model and image plane, respectively. For each plane, two triangular features are extracted from an ellipse and two points based on the polarity in 2-D projection space. A planar homography is first estimated by the triangular feature correspondences, then decomposed into 3-D pose parameters. The proposed method is evaluated through a series of experiments for analyzing the errors of 3-D pose estimation and the sensitivity with respect to point locations.