• Journal of Digital Convergence
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• v.11 no.10
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• pp.359-366
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• 2013

Due to the development and market expansion of image analysis and recognition technology, video security such as CCTV cameras and digital storage devices, are required for real-time monitoring systems and intelligent video security systems. This includes the development of more advanced technologies. A rotatable PTZ camera, in a CCTV camera system, has a zoom function so you can acquire a precise picture. However it can cause blind spots, and can not monitor two or more moving objects at the same time. This study concerns, the intelligent tracking of multiple moving objects, CCTV systems, and methods of video surveillance. An intelligent video surveillance system is proposed. It can accurately shoot broad areas and track multiple objects at the same time, much more effectively than using one fixed camera for an entire area or two or more PTZ cameras.

• Korean Journal of Applied Biomechanics
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• v.19 no.4
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• pp.779-791
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• 2009

The purpose of this study is to develop a program that computes the position of the instantaneous center of rotation while an object moves in a circular motion. For this study, a mathematical algorithm was developed and implemented on the experimental data. Data for pitching (40m carry) and putting (4m) strokes were obtained from a skilled female golfer. A computer program (Centering 1.0) calculated the experimental data and found the radius of the instantaneous center of rotation. When the data were taken broadly, the program produced an error distance of radius. When the data were divided gradually, the program produced a very close instantaneous center of rotation. On comparing pitching and putting strokes, putting was found to have a greater radius than pitching. The instantaneous centers of rotation of putting were not in the golfer's body rather, they were 3m away from the club head. The Centering 1.0 program can calculate the instantaneous center of rotation with at least three sets of experimental data.

• Journal of Aerospace System Engineering
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• v.13 no.3
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• pp.78-86
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• 2019

This paper describes the stiffness optimization of the torsion spring hinge of the large SAR antenna considering the deployment performance. A large SAR antenna is folded in a launch environment and then unfolded when performing a mission in orbit. Under these conditions, it is very important to find the proper stiffness of the torsion spring hinge so that the antenna panels can be deployed with minimal impact in a given time. If the torsion spring stiffness is high, a large impact load at the time of full deployment damages the structure. If it is weak, it cannot guarantee full deployment due to the deployment resistance. A multi-body dynamics analysis model was developed to solve this problem using RecurDyn and the development performance were predicted in terms of: development time, latching force, and torque margin through deployment analysis. In order to find the optimum torsion spring stiffness, the deployment performance was approximated by the response surface method (RSM) and the optimal design was performed to derive the appropriate stiffness value of the rotating springs.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.04a
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• pp.282-286
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• 1995

일반적으로 관성계 내의 물체에 대한 동적특성의 파악을 위해서는 속도, 가속도 및 각속도, 각가속도에 대한 정보를 필요로 하며 자이로는 이중에서 각속도를 측정하는 장치이다. 운동하는 질량에 회전각속도가 인가될 때 발생되는 코리올리힘을 측정하여 회전각속도를 검출하는 개념의 각속도 센서인 진동자이로는 성능이 회전형 자이로에 비해 떨어지나 구조가 간단하고 소형이며 대량생산이 가능한 장점이 있다. 진동자이로의 효시로는 1950년 영국의 Sperry Gyroscope Company의 "Gyroton"이며, 전자기력을 이용한 가진과 측정이 그 특징으로서 실험실 조건에서 지구의 자전속도를 측정할 수 있었다. 그후 1960년대에 General Electric에서 "VYRO"라는 모델을 개발했는데 압전소자를 이용하여 가진과 측정을 하는 방법이 사용되었다. 1980년대에 Watson Ind., Soderkvist등은 센서자체가 압전물질로 만들어진 자이로를 실험하였고 1990년도에 들어서는 진동자이로의 원리를 마이크로 머시닝 기술과 연계시켜서 소형 경량화와 대량생산을 목표로 연구가 일부 진행되고 있다. 현재 제품화되어 실제 응용되고 있는 예로는 무라다사의 삼각프리즘 형태의 자이로, 토킨사의 원통형 자이로 등이 있으며 이러한 자이로는 캠코더 화면의 안정화 장치에 주로 사용되고 있다. 본 논문에서는 압전소자의 압전, 전왜 방정식으로 출발하여 자이로헤드의 동적 거동을 해석하였다. 진동자이로는 물체의 공진주파수에서의 진동현상을 이용하며, 두 방향의 고유진동수를 일치시켜야 하는 등의 설계조건이 있다. 이러한 조건을 만족하도록 사각보 구조를 기본으로 하여 새로운 형태의 자이로헤드를 고안하였다. 자이로헤드의 구동회로를 설계, 해석하고 각속도를 측정할 수 있는 검출회로를 설계하여 설계된 진동자이로의 동적 특성을 확인하고 보정회로를 이용하여 사용 주파수 영역을 넓혔다.이용하여 사용 주파수 영역을 넓혔다.러한 강이성들이 보장되는 제어이론들 중 H$_{\infty}$ 제어이론이 많이 연구/응용 되고 있다. 특히 공칭 플랜트 모델과 함께 사용되는 플랜트 모델과 함께 사용되는 플랜트 불확실성 모델은 직접적으로 성능 및 안정도에 영향을 미치므로 주의 깊게 선정해야 한다. 방법의 실질적인 적용에는 어려움이 있다. 본 연구에서는 기존의 방법들의 단점을 극복할 수 있는 새로운 회귀적 모우드 변수 규명 방법을 개발하였다. 이는 Fassois와 Lee가 ARMAX모델의 계수를 효율적으로 추정하기 위하여 개발한 뱉치방법인 Suboptimum Maximum Likelihood 방법[5]를 기초로 하여 개발하였다. 개발된 방법의 장점은 응답 신호에 유색잡음이 존재하여도 모우드 변수들을 항상 정확하게 구할 수 있으며, 또한 알고리즘의 안정성이 보장된 것이다.. 여기서는 실험실 수준의 평 판모델을 제작하고 실제 현장에서 이루어질 수 있는 진동제어 구조물에 대 한 동적실험 및 FRS를 수행하는 과정과 동일하게 따름으로써 실제 발생할 수 있는 오차나 error를 실험실내의 차원에서 파악하여 진동원을 있는 구조 물에 대한 진동제어기술을 보유하고자 한다. 이용한 해마의 부피측정은 해마경화증 환자의 진단에 있어 육안적인 MR 진단이 어려운 제한된 경우에만 실제적 도움을 줄 수 있는 보조적인 방법으로 생각된다.ofile whereas relaxivity at high field is not affected by τS. On the other hand, the change in τV does not affect low field profile but strongly in fluences on both inflection fie이 and the maximum relaxivity value. The results shows a fluences on both inflection field and the

• Journal of Internet Computing and Services
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• v.17 no.3
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• pp.33-43
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• 2016

In this study, 3D-image based course material has been suggested as a potential pedagogical tool for laboratory courses for aviational maintenance in vocational high schools. With a special focus on assembly/disassembly of the combustion chamber, 3D contents described here are created by Soildworks 2014 based on the textbook widely used in aviational high schools. By analyzing several textbooks currently adopted at various schools, we have clearly shown that the current text-based teaching method is far from being effective regarding providing adequate learning environment for high school students who study aviational maintenance. From the analysis of the conventional textbooks, it is seen that it is urgent that we should come up with more effective and efficient way of teaching methods for these topics at vocational high schools. Using Solidworks, we have developed very vivid 3D image-based course material for topics related to a combustion chamber in the airplane. Newly developed 3D material is seen to clearly show step by step procedures of assembly and disassembly of the combustion chamber which has crucial importance in the aviational laboratory courses. Especially the transparent feature in Solidworks could make it possible to observe the parts covered by outer casing, which can not be seen even in any laboratory class with real objects. 3D animated views could provided unprecedented learning environment for students to acquire core knowledge with ease for the maintenance of a combustion chamber. In order to provide easy access for students to this 3D-based course material, the exclusive viewer is also developed using MS office powerpoint 2007. An example of a learning plan using 3d course material is suggested as well.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.46 no.7
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• pp.542-550
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• 2018

This paper presents design of a bearingless main rotor of SNUF (Seoul National University Flap) blade equipped with active trailing-edge flap to reduce the hub vibratory loads during helicopter forward flight. For that purpose, sectional design of the flexbeam is carried out using the thin-walled composite material rotating beam vibration analysis program (CORBA77_MEMB) in EDISON. Using the multi-body dynamics analysis program, DYMORE, blade dynamic characteristics and those of the loads control are examined using the active trailing-edge flap in terms of the flexbeam sectional design.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.2
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• pp.157-165
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• 2016

In wartime conditionsmilitary combat vehicles are required to be driven on rough roads that have significant obstacles. A wheel type dog-horse robot with a rotary suspension system was applied to overcome the obstacles. To achieve real-time analysis, a simplified model was proposed by using velocity transformations. Through comparison with the multi-body dynamics model, the efficiency and accuracy of the proposed modeling was proven.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.2
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• pp.435-442
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• 2010

The analysis of rigid body traveling along the rotating Timoshenko shaft has been a topic of interest. The problem arose from the observations that as a structure is subjected to moving loads, dynamic deflection as well as stresses can be significantly higher than those for static loads. The establishment of analytical method for the development and maintenance of performance is required in the fields of the machining operations and the position control using ball screw. The equations of motion for the rotating shaft subjected to the two moving forces are derived by using Hamilton's principle. Influence of system parameters such as the speed ratio, the mass ratio and the Rayleigh coefficient is discussed on the response of the moving system.

• Journal of the Korea Institute of Military Science and Technology
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• v.1 no.1
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• pp.128-144
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• 1998

The BEM for linear elastic stress analysis is applied to the highly rotating axisymmetric body problem which also involves the thermoelastic effects due to steady-state thermal conduction. The axisymmetric BEM formulation is briefly summarized and an alternative approach for transforming the volume integrals associated with such body force kernels into equivalent boundary integrals is described in a way of using the concept of inner product and vector identity. A discretization scheme for higher order BE is outlined for numerical treatment of the resulting boundary integral equations, and it is consequently illustrated by determining the stress distributions of the turbine rotor disk of the small turbojet engine(ADD 500) for which a FEM stress solution has been furnished by author.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.7
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• pp.685-692
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• 2016

In this paper, we not only take advantage of the SIFT features in banknote recognition, which has robustness to illumination changes, geometric rotation as well as scale changes, but also propose the hierarchical banknote recognition algorithm, which comprised of feature vector extraction from the frame grabbed image of the banknotes, and matching to the prepared data base of multinational banknotes by ANN algorithm. The images of banknote under the developed UV, IR and white illumination are used so as to extract the SIFT features peculiar to each banknotes. These SIFT features are used in recognition of the nationality as well as face value. We confirmed successful function of the proposed algorithm by applying the proposed algorithm to the banknotes of Korean and USD as well as EURO.