Special Report - 웨어러블 기술과의 만남으로 더 가까워진 실감형 콘텐츠

조선영,Jo, Seon-Yeong 한국정보통신기술협회 2015 TTA저널 Vol.162 No.-

12Cr합금강의 부식열화에 의한 피로파괴 특성

조선영,김철한,배동호,Jo, Seon-Yeong,Kim, Cheol-Han,Bae, Dong-Ho 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.6

In order to investigate the fatigue fracture characteristics by corrosion degradation of 12Cr alloy steel, both the fatigue characteristics in air of them artificially degraded during long period and the corrosion fatigue characteristics were experimentally evaluated in various environments which were determined from electro-chemical polarization tests. And also, their fracture mechanisms were analyzed and compared, fractographyically. From their results, the fracture mechanical characteristics of it artificially degraded during long period in the distilled water, 3.5 wt.% NaCl solution and 12.7wt.%(1M) Na$_2$SO$_4$solution of 25, 60 and 90$\^{C}$ did not show distinguishable difference comparing with non-corroded one in regardless of temperature and degradation period. It means that degradation of the material by just surface corrosion does not remarkably affect to fatigue crack growth. On the other hand, the crack growth rates by corrosion fatigue increased due to activity increase of corrosive factors such as OH(sub)-,Cl(sup)- and SO$_4$(sup)- at the crack tip with temperature increase. Therefore, the crack growth rates by corrosion fatigue were more faster than that in air of the artificially degraded specimen due to the such difference of crack growth mechanism.

고온의 인공해수 중 12Cr강의 부식피로특성에 관한 연구

조선영,김철한,배동호,Jo, Seon-Yeong,Kim, Cheol-Han,Bae, Dong-Ho 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.5

In this study, corrosion fatigue characteristics of 12Cr alloy steel were investigated in 3.5wt.% NaCl solution of 150$^{\circ}C$ and 4.5bar. Behavior of corrosion fatigue cracks was measured by the indirect compliance method and compared with the results in distilled water and in air. 1) 12Cr alloy steel was susceptible to temperature. Its susceptibility was increased as the temperature was increased. 2) The crack growth characteristics of 12Cr alloy steel in distilled water were similar to 3.5wt.% NaCl solution. 3) The temperature of solution affects to the crack growth characteristics of 12Cr alloy steel. In corrosion solutions of 4.5bar, 150$^{\circ}C$, fracture surfaces of corrosion fatigue crack growth at a/W=0.3 was showed the trans-granular fracture suface. As the crack grew up, it was changed to inter-granular type. In condition of high temperature, The crack growth behaviors of 12Cr alloy steel were remarkable.

Turbine Blade재료의 부식민감성과 부식피로특성에 관한 연구

조선영,김철한,류승우,김효진,배동호,Jo, Seon-Yeong,Kim, Cheol-Han,Ryu, Seung-U,Kim, Hyo-Jin,Bae, Dong-Ho 대한기계학회 2000 大韓機械學會論文集A Vol.24 No.3

Corrosion characteristics on the 12Cr alloy steel of turbine blade was electro-chemically investigated in 3.5wt% NaCI and 12.7wt% Na2S04 solution, respectively. Electro-chemical polarization test, Huey test and Oxalic acid etching test were previously conducted to estimate corrosion susceptibility of the material. And, using the horizontal corrosion fatigue tester, corrosion fatigue characteristics of 12Cr alloy steel in distilled water, 3.5wt% NaCI solution, and 12.7wt%(1M) Na2S04 solution were also fracture-mechanically estimated and compared their results. Parameter considered was room temperature, 60'C and 90'C. Corrosion fatigue crack length was measured by DC potential difference method.Obtained results are as follows,1) 12Cr alloy steel showed high corrosion rate in 3.5wt% NaCI solution and Na2S04 solution at high tempratue.2) Intergranular corrosion sensitivity of 12 Cr alloy was smaller than austenitic stainless steel.3) Corrosion fatigue crack growth rate in 3.5wt% NaCI and 12.7wt%(IM) Na2S04 solution is entirely higher than in the distilled water, and also increased with the temperature increase.

광류를 이용한 영상기반 무인항공기의 자세 추정

조선영(Seon-Yeong Jo),김종훈(Jong-Hun Kim),김정호(Jung-Ho Kim),조겸래(Kyeum-Rae Cho),이대우(Dae-Woo Lee) 한국항공우주학회 2010 韓國航空宇宙學會誌 Vol.38 No.4

UAV는 임무 수행을 위한 INS 장비와 광학 장비를 갖추고 있다. 이 논문에서는 UAV를 위한 알고리즘으로 칼만 필터와 광류를 이용하는 영상기반 자세추정 알고리즘을 제안한다. 광류는 UAV에 장착된 카메라의 영상으로부터 획득하며 UAV의 자세는 광류를 통해 측정된다. 이 논문에서 UAV 자세의 추정과 낮은 신뢰성을 보완하기위해 칼만 필터를 사용한다. 그리고 실험을 통해 알고리즘을 검증하였다. Rate table과 실제 비행영상을 이용하여 실험 하였으며, 본 논문에서 UAV의 자세 추정 알고리즘 검증 결과를 보였다. Rate table 실험에서 오차는 2도 이내였으며, AHRS를 통해 측정한 결과와 비슷한 경향을 보인다. 그러나 실제 비행 영상 실험에서 최대 Yaw 오차는 21도였으며, 최대 Pitch 오차는 7.8도로 나타났다. UAV (Unmanned Aerial Vehicle) have an INS(Inertial Navigation System) equipment and also have an electro-optical Equipment for mission. This paper proposes the vision based attitude estimation algorithm using Kalman Filter and Optical flow for UAV. Optical flow is acquired from the movie of camera which is equipped on UAV and UAV's attitude is measured from optical flow. In this paper, Kalman Filter has been used for the settlement of the low reliability and estimation of UAV's attitude. Algorithm verification was performed through experiments. The experiment has been used rate table and real flight video. Then, this paper shows the verification result of UAV's attitude estimation algorithm. When the rate table was tested, the error was in 2 degree and the tendency was similar with AHRS measurement states. However, on the experiment of real flight movie, maximum yaw error was 21 degree and Maximum pitch error was 7.8 degree.

무인 항공기의 영상기반 목표물 추적과 광류를 이용한 상대깊이 추정

조선영(Seon-Yeong Jo),김종훈(Jong-Hun Kim),김정호(Jung-Ho Kim),이대우(Dae-Woo Lee),조겸래(Kyeum-Rae Cho) 한국항공우주학회 2009 韓國航空宇宙學會誌 Vol.37 No.3

최근 무인 항공기(Unmanned Aerial Vehicle, UAV)는 다양한 임무수행이 가능한 무인 시스템이라는 점에서 크게 주목받고 있다. 특히 정찰, 추적 등의 임무는 영상을 이용하여 임무 수행이 이루어진다. 소형 무인 항공기의 경우 중량과 비용을 고려하여 단안 영상을 이용하는 임무 수행 연구가 활발하게 이루어지고 있다. 그러나 실제 지표면과 목표물이 고도 차이를 가지고 있어, 영상의 상대 깊이를 고려하지 않은 3차원 거리는 임무 수행 시 오차 요인으로 작용 할 수 있다. 본 연구에서는 상대 깊이 추정을 위한 평균이동 알고리즘, 광류, 부분 공간법에 관하여 차례로 제시한다. 평균이동 알고리즘은 영상 내 목표물 추적과 관심영역을 결정하며 광류는 영상의 밝기를 이용한 영상 이동 정보를 포함한다. 마지막으로 부분 공간법은 영상안의 움직임을 추정하며 각 영역의 상대깊이를 결정한다. Recently, UAVs (Unmanned Aerial Vehicles) are expected much as the Unmanned Systems for various missions. These missions are often based on the Vision System. Especially, missions such as surveillance and pursuit have a process which is carried on through the transmitted vision data from the UAV. In case of small UAVs, monocular vision is often used to consider weights and expenses. Research of missions performance using the monocular vision is continued but, actually, ground and target model have difference in distance from the UAV. So, 3D distance measurement is still incorrect. In this study, Mean-Shift Algorithm, Optical Flow and Subspace Method are posed to estimate the relative depth. Mean-Shift Algorithm is used for target tracking and determining Region of Interest (ROI). Optical Flow includes image motion information using pixel intensity. After that, Subspace Method computes the translation and rotation of image and estimates the relative depth. Finally, we present the results of this study using images obtained from the UAV experiments.

다층용접배관 용접부에서 균열닫힘현상을 고려한 피로균열성장특성 평가

김철한,조선영,배동호,Kim, Cheol-Han,Jo, Seon-Yeong,Bae, Dong-Ho 대한기계학회 2001 大韓機械學會論文集A Vol.25 No.5

To obtain representative fatigue crack growth characteristic curve in residual stress field, fatigue crack growth test was carried out at various stress ratio and fatigue crack growth characteristic curve was represented using crack closure concept. Obtained results are as follows;K(sub)op/K(sub)max was independent of K(sub)max when R was lower than 0.5 and crack closure phenomenon was not observed when R is higher than 0.5. therefore neglecting crack closure behaviour, actual fatigue crack growth rate can be underestimated. Thus, considering crack closure phenomenon, fatigue crack growth characteristics curve of A 106 Gr B Steel weldment can be effectively estimated.

인 변성 폴리우레탄 에멀젼의 합성에 관한 연구

우종표 ( U Jong Pyo ),조선영 ( Jo Seon Yeong ) 한국유화학회 2003 한국응용과학기술학회지 Vol.20 No.4

N/A Aqueous polyurethane dispersion was synthesized using phosphorus compound which received significant attention for the replacement of halogenated flame retardants. In this study, polyols which have phosphorus moity in their structural unit were synthesized by two-step polycondensation reaction using dimethyl phenylphosphonate, ethylene glycols, adipic acid, and 1,4-butanediol. In the next step, polyurethane dispersion was prepared using these polyols, isophorone diisocyanate with dimethyl propionic acid. The particle size of polyurethane latex was reduced from 347㎚ to 240㎚ with increasing DMPA content. It was observed that the LOI values of prepared coatings increased from 27% to 35% with increasing phosphorus content.

슬러지의 선택적 분리를 위한 침전지의 직렬운전에 관한 연구

정팔진 ( Jeong Pal Jin ),조선영 ( Jo Seon Yeong ),정진필 ( Jeong Jin Pil ),이은주 ( Lee Eun Ju ) 한국물환경학회 2003 한국물환경학회지 Vol.19 No.6

A wide variety of research concerning the functions about biological reactor has been performed in many practical area. Besides these functions, a particular interest is the selection of activated sludge which comes into the final clarifiers. It has been found that microorganisms which prevent the setting and it can be controlled with this method. As a result, the influence a bulking can be reduced. On the other hand, bulking controls by microorganisms of selective setting character have been rarely studied at the activated sludges aeration basin. Our present study, is focus to, see how much effective the series operation(S-1) is compared to the parallel(P-1) one by studying the management of the final clarifiers functioning in the two different ways : parallel and series. There were mainly three stage for the operating period. First stage(Run-1 ; was the bulking which is induce, in particular period and the settleability in each reactor was compared at second stage(Run-2) when the sludge bulking was produced. Finally, P-1 and S-1 which is experimented in Run-2 were switched at third stage(Run-3). When microorganisms, which is cause the bulking, grew massively, sludge settleability of S-1 is superior to that P-1. This outcome stemmed from the fact that only by microorganisms, which have a good settleability were returned to the clarifiers of S-1 reactor at the first stage. In addition, although microorganisms grew massively, as well as a good sludge settleability was kept at the second stage because microorganisms, which are the cause of bulking were wasted.

그룹웨어 ASP 사업의 현재와 미래 -비즈메카 그룹웨어를 중심으로

윤준호 ( Yun Jun Ho ),조선영 ( Jo Seon Yeong ),최원석 ( Choe Won Seog ) 한국정보처리학회 2003 정보처리학회지 Vol.10 No.6