• International Journal of Aerospace System Engineering
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• 제4권1호
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• pp.13-21
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• 2017

In this paper, we present some results on performance analysis for flap actuation system of aircraft. For this, by utilizing MATLAB/Simulink solution, which is widely used physical model-based design tool, we particularly construct the architecture of the analysis model consisting of the main three phases: 1)commanding and outer-controlling the flap angle through flight control computer; 2)generating hydraulic/mechanical power through control module and power drive unit; 3)transmitting torque and actuating the flap through torque tube and rotary geared actuators. For mimicking the motion of the actual flap, we apply each mechanical component, which is already being used in actual aircraft, to our performance analysis model so that it guarantees the congruency of the simulation results. That is, we reflect the actual specifications of flap hardware and software as parameters of the model. Finally, simulation results are presented to illustrate the model.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.1458-1463
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• 2004

Tracking is one of the most important pre-required task for many application such as human-computer interaction through gesture and face recognition, motion analysis, visual servoing, augment reality, industrial assembly and robot obstacle avoidance. Recently, 3D information of object is required in realtime for many aforementioned applications. 3D tracking is difficult problem to solve because during the image formation process of the camera, explicit 3D information about objects in the scene is lost. Recently, many vision system use stereo camera especially for 3D tracking. The 3D feature based tracking(3DFBT) which is on of the 3D tracking system using stereo vision have many advantage compare to other tracking methods. If we assumed the correspondence problem which is one of the subproblem of 3DFBT is solved, the accuracy of tracking depends on the accuracy of camera calibration. However, The existing calibration method based on accurate camera model so that modelling error and weakness to lens distortion are embedded. Therefore, this thesis proposes 3D feature based tracking method using SVM which is used to solve reconstruction problem.

• 대한물리의학회지
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• 제13권1호
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• pp.99-105
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• 2018

PURPOSE: The aim of this study was to evaluate the concurrent validity and clinical usefulness of the universal plastic goniometer to measure the range of motion of the internal and external rotation of the hip joint using the three dimensional motion analysis which can analyze the joints and segment movements in the most objective and quantitative method. METHODS: Clinical and kinematic data were collected from thirty individuals using a universal plastic goniometer and a ten camera motion analysis system. Passive hip rotation range was obtained three trials for left and right hip joints using two measure methods simultaneously. RESULTS: There were significant differences between all matching measures of the two measures of internal and external rotation of the hip joint (p<.05). The relationship between the two tests for all measurements of the internal and external rotation of the hip was statistically significant with correlation coefficient form r=.87 to .96. (p<.01). CONCLUSION: Clinical measurement of the internal and external rotation of the hip using a universal plastic goniometer is effective to assess the hip condition. However, application of universal plastic goniometer requires careful attention in more accurate evaluation and research verification of the internal and external rotation of hip joint.

• 대기
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• 제17권1호
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• pp.1-15
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• 2007

A constraint based on climatology is introduced to the cost function of the three-dimensional variational assimilation (3dVar) to correct the error of the zonal mean wind structure in the global data assimilation system at Korea Meteorological Administration (KMA). The revised cost function compels the analysis fit to the chosen climatology while keeping the balance between the variables in the course of analysis. The constraint varies selectively with the vertical level and the horizontal scale of the motion. The zonally averaged wind field from European Centre for Medium-Range Weather Forecasts Re-Analysis 40 (ERA-40) is used as a climatology field in the constraint. The constraint controls only the zonally averaged stratospheric long waves with total wave number less than 20 to fix the error of the large scale wind field in the stratosphere. The constrained 3dVar successfully suppresses the erroneous westerly in the stratospheric analysis promptly, and has been applied on the operational global 3dVar system at KMA.

• 제어로봇시스템학회논문지
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• 제7권4호
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• pp.309-318
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• 2001

In this paper, we describe methods that analyze a human gesture. A human interface(HI) system for analyzing gesture extracts the head and hand regions after taking image sequence of and operators continuous behavior using CCD cameras. As gestures are accomplished with operators head and hands motion, we extract the head and hand regions to analyze gestures and calculate geometrical information of extracted skin regions. The analysis of head motion is possible by obtaining the face direction. We assume that head is ellipsoid with 3D coordinates to locate the face features likes eyes, nose and mouth on its surface. If was know the center of feature points, the angle of the center in the ellipsoid is the direction of the face. The hand region obtained from preprocessing is able to include hands as well as arms. For extracting only the hand region from preprocessing, we should find the wrist line to divide the hand and arm regions. After distinguishing the hand region by the wrist line, we model the hand region as an ellipse for the analysis of hand data. Also, the finger part is represented as a long and narrow shape. We extract hand information such as size, position, and shape.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1995년도 추계학술대회 논문집
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• pp.565-568
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• 1995

This paper presents the position control of a closed-loop cylinder system using ER(electro-rheological)valve actuators. Following the field-dependent pressure analysis of the ER valve actuators on the basis of Bingham model of ER fluids, a 3 d.o.f. close-loop sylinder system having the heave, roll and pitch motions is proposed. The governing equations of motion are derived using Lagrange's equation, and a control model is established by considering system uncertain parameters such as load conditions. A sliding mode controller which has inherent robustness to system uncertainties is adopted to achieve robust tracking control performance. Tracking control results for sinusoidal trajectory were presented in order to demonstrate the effectiveness of the proposed control system.

• 한국통신학회논문지
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• 제36권5B호
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• pp.502-510
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• 2011

본 연구에서는 보행 시 발의 3차원 움직임에 대한 보다 정확한 동작 각도를 측정하고, 기존의 마커 방식에 의한 유선 동작 분석 시스템의 불편함을 해결하기 위해서 양상에 실제 사용 가능한 족부 진단용 우선 이동형 시스템을 개발하였다. 시스템의 주요 모듈은 3축 가속도계와 3축 자이로계로 이루어진 관성 측정 장치와 블루투스 전송 모듈로 구성되었다. 피험자는 전주 소아과 족부 임상 전문의에게 평발과 아킬레스건염을 진단 받은 소아과 환자 5명의 10족 에 대한 측정을 하였으며, 족부 전문의의 이학적 소견과 대비하여 개발 시스템에서 측정한 값과 근전도 데이터를 바탕으로 그 타당성을 평가하였다. 발목의 ROM은 외측 복사뼈에서 측정된 최대 피크와 최소 피크의 차이로 측정하였고, 이 값에 근거하여 평발이 심할수록 외번의 비율이 상대적으로 높아짐을 보였다. 근전도 측정 결과 내번근으로 작용하는 전경골근의 보상 작용으로 인해 전경골근의 근 활성도가 높게 측정되었고, 아킬레스건염에 의해 족배굴곡이 제한됨으로 인해 족저굴곡근으로 작용하는 비복근의 근 활성도가 높아짐을 보임으로서 족부 질환에 따르는 발의 비정상적인 움직임과 특정 근육의 활성 사이에 상관성이 있음을 확인 하였다.

• 한국분무공학회지
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• 제8권1호
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• pp.1-8
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• 2003

The flow analysis of the axial fan of rotary burner was performed by SIMPLE(Semi Implicit Method for Pressure Linked Equations) algorithm and finite volume mothod performed in the case of 3-D, incompressible, turbulent flow. In this study, the coordinate transformation was adapted for the complex geometry of axial fan, and the standard $k-{\varepsilon}$ model and wall function method were used for analysis of turbulent flow. Multi-block grid system was used for flow field and divided into four domains such as the inlet, outlet, flow field of rotating vane, and tip clearance. Fan rotation was simulated by rotational motion using MRF(Multiple Rotating Reference Frame) in steady, incompressible state flow.

• Ocean Systems Engineering
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• 제13권4호
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• pp.349-365
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• 2023

Targeting a floating wave and offshore wind hybrid power generation system (FWWHybrid) designed in the Republic of Korea, this study examines the impact of the interaction, with multiple wave energy converters (WECs) placed on the platform, on platform motion. To investigate how the motion of WECs affects the behavior of the FWWHybrid platform, it was numerically compared with a scenario involving a 'single-body' system, where multiple WECs are constrained to the platform. In the case of FWWHybrid, because the platform and multiple WECs move in response to waves simultaneously as a 'multi-body' system, hydrodynamic interactions between these entities come into play. Additionally, the power take-off (PTO) mechanism between the platform and individual WECs is introduced for power production. First, the hydrostatic/dynamic coefficients required for numerical analysis were calculated in the frequency domain and then used in the time domain analysis. These simulations are performed using the extended HARP/CHARM3D code developed from previous studies. By conducting regular wave simulations, the response amplitude operator (RAO) for the platform of both single-body and multi-body scenarios was derived and subsequently compared. Next, to ascertain the difference in response in the real sea environment, this study also includes an analysis of irregular waves. As the floating body maintains its position through connection to a catenary mooring line, the impact of the slowly varying wave drift load cannot be disregarded. To assess the influence of the 2^nd-order wave exciting load, irregular wave simulations were conducted, dividing them into cases where it was not considered and cases where it was included. The analysis of multi-degree-of-freedom behavior confirmed that the action of multiple WECs had a substantial impact on the platform's response.

• 대한산업공학회지
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• 제22권3호
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• pp.387-398
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• 1996

In this study the cell arrival processes from pre-buffer into multiplexer for MPEG(Motion Picture Experts Group) coding video sources are analyzed with consideration of the traffic periodicity in frame level. The analysis is performed by introducing the two arrival models, that is, periodic on/off source model and periodic uniform arrival model. Modulated $N^*D$/D/1 queueing system is utilized in periodic on/off source model, while ${\Sigma}{N_i}^*D_i$/D/1 queueing system is used in periodic uniform arrival model. The presented models are validated by comparing with computer simulations. Numerical results for periodic uniform arrival model are shown to be very accurate, but those of periodic on/off source model are shown to be inaccurate as the number of sources are increased.