• Current Research on Agriculture and Life Sciences
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• v.32 no.3
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• pp.159-163
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• 2014

Agricultural unmanned helicopters have become a new paradigm for aerial application. Yet, such agricultural helicopters require easy and affordable attitude control systems. Therefore, this study presents an affordable attitude measurement system using a DCM (direction cosine matrix) algorithm that would be applied to agricultural unmanned helicopters. An IMU using a low-cost MEMS and an algorithm to estimate the attitude of the helicopter were applied in a gimbals structure to evaluate the accuracy of the attitude measurements. The estimation errors in the attitude were determined in comparison with the true angles determined by absolute position encoders. The DCM algorithm and sensors showed an accuracy of about 1.1% for the roll and pitch angle estimation. However, the accuracy of the yaw angle estimation at 3.7% was relatively larger. Such errors may be due to the magnetic field of the stepping motor and encoder system. Notwithstanding, since the intrinsic behavior of the agricultural helicopter remains steady, the determination of attitude would be reliable and practical.

• Journal of Digital Convergence
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• v.16 no.11
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• pp.543-551
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• 2018

This study investigated the effects of corrective exercise and TECAR on cervical alignment, pain threshold, and pain in forward head posture patients. The subject includes 30 forward head posture patients. In the intervention methods, the experimental group combined corrective exercise and TECAR treatment. Only the corrective exercise was applied to the control group. Assessments were made on cervico vertebra angle (CV angle), pain pressure threshold (PPT) and neck disability index (NDI) visual analog scale (VAS). The intervention was conducted six times a week for two weeks. Both groups showed significant differences in CV angle, PPT, NDI, and VAS. Also, PPT, NDI, and VAS excluding CV angle were significantly improved in the study group compared to the control group. These results suggest that the intervention method that combines corrective exercise and TECAR treatment has a more positive effect on pain and ADL ability of forward head posture patient.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.5
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• pp.335-343
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• 2019

The third stage of the KSLV-II is equipped with the reaction control system that performs three axis-control during non-thrust coasting phase and performs a roll axis control during thrust phase. Toxic propellants such as hydrazine have been used for conventional rocket propulsions, however, recently, more studies have been conducted on the use of non-toxic eco-friendly propellants such as ADN and HAN. Especially, hydrogen peroxide has received a growing focus as an emerging propellant. It is considered an alternative of the toxic propellants because of economic advantage in producing the system, conducting operation test, and evaluation of the test result. In this paper, we describes the design, prototype, testing and evaluation of the test results with the 50 N-level hydrogen peroxide monopropellant thruster system which is currently under development.

• Journal of the Korea Society of Computer and Information
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• v.27 no.2
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• pp.9-14
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• 2022

In this study, we propose a method for moving a device such as a flexible air sculpture while stably maintaining the user's desired posture. To accomplish this, a robot system with a structure of a mobile robot capable of running according to a given trajectory was studied by applying the PI algorithm and horizontal maintenance posture control using IMU. The air sculptures used in this study often use thin strings in a fixed posture. Another method is to put a load on the center of gravity to maintain the posture, and it is a system with flexibility because it uses air pressure. It is expected that these structures can achieve various results by combining flexible structures and mobile robots through the convergence process of digital sensor technology. In this study, posture control was performed by fusion of the driving technology of AGV(Automatic Guided Vehicle),, a field of robot, and technologies applying various sensors. For verification, the given performance evaluation was performed through an accredited certification test, and its validity was verified through an experiment.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.12
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• pp.509-516
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• 2022

Accurate pose prediction of objects in 3D space is an important visual recognition technique widely used in many applications such as scene understanding in both indoor and outdoor environments, robotic object manipulation, autonomous driving, and augmented reality. Most previous works for object pose estimation have the limitation that they require an exact 3D CAD model for each object. Unlike such previous works, this paper proposes a novel neural network model that can predict the poses of unknown objects based on only their RGB color images without the corresponding 3D CAD models. The proposed model can obtain depth maps required for unknown object pose prediction by using an adaptive depth estimator, AdaBins,. In this paper, we evaluate the usefulness and the performance of the proposed model through experiments using benchmark datasets.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.3
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• pp.19-27
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• 2010

KSLV(Korea Space Launch Vehicle)-I is designed as a launch vehicle to enter a 100 kg-class satellite to the LEO(Low-Earth Orbit). Attitude angles of the upper-stage, including roll, pitch and yaw are controlled by cold gas thruster system using nitrogen gas. The thruster for the KSLV-I is the main pneumatic valve in the RCS(Reaction Control System). In this paper, the design, function tests, and environment tests of the thruster for KSLV-I are described. The developed thrusters are experimentally evaluated and successfully passed the required qualification and acceptance tests.

• Journal of the Korean Institute of Intelligent Systems
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• v.20 no.5
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• pp.677-682
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• 2010

This paper addresses a method of estimating roughly the human pose by comparing Haar-wavelet value which is learned in face detection technology using AdaBoost algorithm. We also presents its application to face recognition. The learned weak classifier is used to a Haar-wavelet robust to each pose's feature by comparing the coefficients during the process of face detection. The Mahalanobis distance is used to measure the matching degree in Haar-wavelet selection. When a facial image is detected using the selected Haar-wavelet, the pose is estimated. The proposed pose estimation can be used to improve face recognition speed. Experiments are conducted to evaluate the performance of the proposed method for pose estimation.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.3
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• pp.243-250
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• 2012

In this paper, a systematic consequence of evaluation method, procedure, and flight data analysis is investigated for application of ADS-33E-PRF to UAV. And it is applied to unmanned rotorcraft for evaluation. CNUHELI-020, which is developed in Chungnam National University, is used for assessment of handling quality: decoupled longitudinal and lateral/directional model were used to assess handling qualities. Evaluation flight maneuvers are categorized as hover/low-speed requirements, small-amplitude attitude change, and moderate-amplitude attitude change requirements.

• Journal of Radiation Protection and Research
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• v.38 no.4
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• pp.242-245
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• 2013

Monte Carlo method was applied to discriminate the external contamination on radiation workers in nuclear power plants for internal dose assessment generally used with a bed type scanning detector whole body counter. Korean voxel model with internal contamination was used to estimate the detection patterns of whole body scanning. Also, the BOMAB model with various external contamination was assumed to compare with detection of radionuclides inside the human body. From the comparison of detection efficiency between front and back side up, external contamination was easily distinguished.

• Proceedings of the ESK Conference
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• 1995.10a
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• pp.127-140
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• 1995

인간이 자연스럽게 선 자세를 취하는 경우, 그 신체의 균형은 주로 시각과 전 정미로계, 소뇌 및 근고유감각의 정보에 의하여 미세하게 조절된다. 그러나 일단 편마비, Parkinson's Disease, 골관절 질환, 실명등의 평형기능을 지해하는 장해를 받데 되면, 정상 적인 자세제어는 곤란하게 된다. 이러한 장해를 진단.치료해 가는 데에 재활의학에 있어서는 관절가동역 Test, 거수능력 Test, 일상생활동작 Test등의 평가방법이 이용되고 있고, 골관절 질환에 있어서는 방사선사진에 의존도가 높다. 그러나 어느 방법을 선택하든지간에 의사나 실제로 검사를 하는 검사자의 주관에 의한 것이 많고, 또 어느 정도 가능한가라는 정성적 판단이 대부분이다. 따라서 객관적이면서도 정량적으로 평가할 수 있는 지표를 찾아서 위의 방법과 병행하는 것이 진단에 있어서 더욱 신뢰성을 높이고, 환자 자신도 병의 진행과정과 치료효과를 쉽게 이해 할 수 있다고 생각된다.