• 한국자동차공학회논문집
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• 제5권5호
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• pp.170-177
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• 1997

In this study, an analysis technique using simple beam model for predicting structure crashworthiness of the passenger car side impacted with an angle by another passenger car was investigated. The simple model was composed of major beam-like side structure which carry almost all side impact load. A procedure of component collapse test, calculation of load carrying capability and dynamic simulation was carryed out sequentially. Transient dynamic algorithms and a computer program to simulate deformations and motions of the impacted car was developed. The developed procedure was applied to a 3 door passenger car side impacted with an angle of 75 degree and the analysis results show good agreements with the actual test results.

• Journal of Advanced Marine Engineering and Technology
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• 제32권8호
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• pp.1285-1295
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• 2008

A research on a simulator for a side walking path of a 16 degree-of-freedom (d.o.f) biped walking robot(BWR) which is composed of 4 d.o.f upper-part body and 12 d.o.f lower-part of the body is presented. For generation of stable side walking motion, the kinematics, dynamics and the zero moment of point(ZMP) of the BWR were analyzed analytically and included in the simulator. To operate the motion simulator for stable side walking of the BWR, a graphic user interface program was developed which needs inputs for the side distance between legs, base joint angle, walking type, and walking velocity. The simulator was developed to generate joint angle data of legs for side walking, and the data are transmitted to the BWR for stable side walking. In the simulator, a new path function for smooth walking motion was proposed and applied to the simulator and actual motion of a BWR. Also for actual side walking, an algorithm for estimating backlashes of the actuating joint motors was proposed and included in the simulator. To validate the performance of the proposed motion simulator, the simulator was operated and its side walking data of the simulator were generated for a period of side walking.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
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• pp.533-539
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• 1993

In this paper, two side-attack guidance laws for an underwater vehicle are considered. In order to find the guidance command, we first make use of the optimal guidance law with terminal impact angle constraint. Secondly, the optimal solution of tracking problem is used. This paper shows some brief theory which is used in deriving the side-attack guidance laws, and the method of computing these guidance laws. Simulations on underwater vehicle for a constant moving target prove that the suggested side-attack guidance laws have enhanced side attack performance over the optimal guidance law with miss distance weighting only. Furthermore, from simulation results. we conclude that the guidance law using the optimal solution of tracking problem is more efficient for the side-attack guidance than the optimal guidance law with terminal impact angle constraint.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2007년도 제28회 춘계학술대회논문집
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• pp.335-338
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• 2007

공대공미사일의 경우 초음속 하에서 고 기동성을 얻기 위하여 고받음각 능력이 요구되어진다. 옆 미끄러짐이 없는 대칭형 세장형 몸체의 경우라도 비대칭 와류는 생성된다. 이러한 비대칭 와류는 불필요한 측력 및 요잉모멘트를 발생시키고 이는 곧 방향 안전성을 저하시킨다. 본 연구는 전산해석을 통하여 초음속유동하에서 세장형 몸체 주변에 발생되는 비대칭와류 모사를 실시하였으며 비대칭 와류의 모사를 위해 선두부에 Bump를 장착하였다. 전산해석 결과 세장형 몸체 주변에 발생하는 비대칭와류를 모사 할 수 있었다.

• 대한방사선기술학회지:방사선기술과학
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• 제42권6호
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• pp.423-428
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• 2019

The Precise measurement of the knee's Congruence angle is required for diagnosis of patella dislocation. The purpose of this study is to consider the distortion diagram and usefulness about the test of the bilateral side and one side through the evaluating congruence angle from Merchant view of patellofemoral joint to central X-ray. We've evaluated the sulcus angle and Congruence angle following central X-ray's changes when we took Merchant view of patellofemoral joint aimed to right lower limb from human whole body phantom. The subject of the evaluation was classified as normal group and varus group, and the varus group has experimented with External rotation of legs as 15° and 30°. When normal groups result as 0, 7.5, 15 cm, it was measured as 17.25 ± 1.34°, 19.60 ± 1.41°, 20.55 ± 1.77° each. The gap between minimal and maximum angle was 3.3°, and the value was shown as getting bigger when it further away from the centeral X-ray. When Congruence angle in 15° varus group was 0, 7.5, 15 cm, it was each 16.45 ± 1.34°, 17.10 ± 0.99°, 17.80 ± 1.13°. And when Congruence angle in 30° varus group was 0, 7.5, 15 cm, it was measured each 18.35 ± 1.63°, 18.95 ± 1.06°, 19.60 ± 1.41°. The difference between minimum and maximum of angle in 15° varus group and 30° varus group was each 1.35° and 1.25°, the angles have shown as increasing the further away from the center. The patellofemoral joint showed that the congruence angle increases as the further away from Central X-ray, and also it is judged that is possible to change the congruence angle by a degree of varus knee. Thus, accurate measurement of the congruence angle is shown to advantage that methods for examining by split each side at two times than methods for examining both sides at a time. Therefore, it is expected to helpful on the diagnostic side of patella dislocation and subluxation.

• 한국산학기술학회논문지
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• 제13권8호
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• pp.3513-3520
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• 2012

본 연구는 뇌졸중 환자와 정상 성인이 앉은 자세에서 동적으로 변화하는 지지면의 각도에 적응하여 신체를 정위시키는 능력에 차이가 있는지 알아보기 위해 실시되었다. 뇌졸중 환자 12명(남 6명, 여 6명)과 정상 성인 12명(남 6명, 여 6명)을 대상으로 실시하였고, 앉은 자세에서 지지면을 2가지 방향(우세측, 비우세측)으로 기울였을 때 수직선과 머리와 체간이 이루는 각도를 영상 동작 분석 시스템을 이용하여 측정하였다. 앉은 자세에서 우세한 쪽을 올렸을 때 뇌졸중 환자와 정상 성인의 사이의 머리와 체간의 각도는 유의한 차이를 보였다(p<0.05). 앉은 자세에서 비우세한 쪽을 올렸을 때 뇌졸중 환자와 정상 성인 사이의 머리와 체간의 각도는 유의한 차이를 보였다(p<0.05). 앉은 자세에서 비우세한 쪽을 내렸을 때 뇌졸중 환자와 정상 성인 사이의 머리와 체간의 각도는 유의한 차이를 보였다(p<0.05). 앉은 자세에서 우세한 쪽을 내렸을 때 뇌졸중 환자와 정상 성인 사이의 머리의 각도는 유의한 차이를 보였으나(p<0.05) 체간의 각도는 유의한 차이를 보이지 않았다(p>0.05). 본 연구의 결과, 뇌졸중 환자들이 정상 성인에 비해 동적으로 변화하는 지지면의 각도에 적응하여 신체를 정위시키는 능력에 있어서 다양한 결손이 있음을 확인하였다. 뇌졸중 환자가 앉은 자세에서 환경의 변화에 적응하여 신체를 정위시키는 능력의 분석을 통해 뇌졸중 환자의 앉은 자세 조절의 문제점을 좀 더 명확히 이해할 수 있을 것으로 여겨진다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년도 제30회 춘계학술대회논문집
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• pp.71-76
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• 2008

본 연구에서는 아음속 영역에서 유도무기의 일반적 형상인 세장형 몸체를 갖는 서로 다른 선두부 형상의 두 모델을 이용하여 받음각에 다른 세장형 모델 윗면의 압력 분포를 측정하였다. 아음속 영역에서 서로 다른 선두부 형상을 갖는 두 모델의 받음각에 따른 공력실험 결과로 특정 받음각에서의 측력 및 요잉모멘트가 최대가 되는 것을 확인하였으며 비대칭 정상상태와 비대칭 비정상상태의 경계를 알 수 있었다. 또한 시간에 따른 측력, 항력 및 요잉모멘트의 결과로 같은 받음각이라도 선두부의 형상에 따라 안정성이 다른 결과를 보였다. 받음각에 따른 세장형 몸체 표면 압력 분포를 측정한 결과 받음각이 증가할수록 표면압력 분포는 비대칭적으로 형성됨을 알 수 있었다.

• 한국농공학회지
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• 제28권4호
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• pp.49-56
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• 1986

This study was carried out to investigate mechanical characteristics of the uniformly loaded skew-plate at 4 kinds of boundary condition : i) all edges are clamped (BC-1) , ii) all edges are simply supported (BC- 2), iii) two opposite edges are clamped and the other two edges are free (BC-3), and iv )two opposite edges are simply supported and the other two edges are free (BC-4). Various skew angles, 0$^{\circ}$, 10$^{\circ}$, 15$^{\circ}$, 30$^{\circ}$, 40: 45: and 60, of the plate were tested for the above boundary conditions. Resutts obtained from the study are summarized as follows ; 1.The lateral displacement at the center of a skew- plate was decreased as the skewangle increased at all of the boundary conditions. The decrements of the conditions of BC-3 and BC-4 were considerable. And, difference of the displacement between the boundary conditions was decreased as the skew-angle was increased. 2. X-moments (to the Y-axis) at the center of a skew- plate and the minimum principal moments were shown as a similar pattern of change with respect to the skew-angle variation between BC-i and BC-2 and between BC-3 and BC-4, and the pattern of change at the conditions of BC-3 and BC-4 were shown higher rates than those for the conditions of BC-i and BC-2 3.Y-moments (to the X- axis) at the center of a skew-plate and the maximum principal moment were decreased as the skew-angle increased in a similar pattern at all of the boundary conditions. 4.X-moments at the obtuse angle side of a skew-plate were shown as a parabolic pattern of change (frist increased after then decreased) as the skew-angle increased, and a skew-angle resulting the maximum absolute moment was depended on the boundary conditions. 5.Y-moments at the obtuse angle side of a skew-plate were affected by the skewangle much more at the boundary condtions of BC-2 and BC-4 than at the conditions of BC-i and BC-3. 6.Maximum principal moments at the obtuse angle side of a skew-plate at the skew angle of 40$^{\circ}$- 45$^{\circ}$ were resulted almost the same value at all of the boundary conditions .

• 한국군사과학기술학회지
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• 제5권3호
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• pp.77-86
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• 2002

An experimental study of the vortex interaction characteristics of a delta wing/LEX configuration was conducted in a wind tunnel using the micro water droplet and laser beam sheet visualization technique. The main focus of this study was to analyze the effect of the angle of attack and sideslip angle on the vortex interaction and vortex breakdown. These tests were accomplished at angles of attack between $16^{\circ}$ and $28^{\circ}$ and sideslip angle between $0^{\circ}$ and $-15^{\circ}$ at free-stream velocity of 6.2 m/s. Flow visualization data provide a description of the vortex interaction between LEX and wing vortices, and of the vortex breakdown. The introduction of LEX vortex stabilized the vortical flow, and delayed the vortex breakdown up to higher angle of attack. The vortex interaction and breakdown was promoted on the windward side, whereas they are suppressed on the leeward side.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1997년도 추계학술대회 논문집
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• pp.112-115
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• 1997

In this paper, we investigated the liquid crystal(LC) alignment and generation of pretilt angle by using photo-alignment techniques on two kinds of polyimide(Pl) surface. It was found that the uniform alignment for nematic(N) LC is obtained in a cell with slanted UV light irradiation on PI surface without side-chain. We successfully observed that the pretilt angle of NLC is generated about 3.3 degrees in a cell with an incidence angle of 70 degrees on PI surface without side chain. It is considered that the pretilt angle generation in NLC is attributed to interaction between the LC molecular and the polymer.