60kg/mm2급 조질고장력강의 용접입열량에 따른 기계적 특성 변화

김은석,박경채,정인상 ( O . S . Kim,K . C . Park,I . S . Chung ) 한국열처리공학회 1994 熱處理工學會誌 Vol.7 No.1

For the purpose of studying the change of mechanical properties of weld parts, shielded metal arc welding, one-pole and two-pole submerged arc welding were accomplished weldability on 60㎏/㎟ quenched and tempered high strength steel. Charpy impact values of the weld metal in welded parts by SMAW and SAW were lower than those of the heat affected zone and increased in order of bond, coarsened, refined and carbon spheroidized regions in the heat affected zone. Grain size of prior austenite or M-A constituent did not significantly affect toughness of welded parts, but precipitated carbide films which forms at the grain boundaries or within matrix and volume fraction of pearilte were most important factor for toughness.

60kg/mm²급 조질고장력강의 용접입열량에 따른 기계적 특성 변화

김은석,박경채,정인상,Kim, O.S.,Park, K.C.,Chung, I.S. 한국열처리공학회 1994 熱處理工學會誌 Vol.7 No.1

For the purpose of studying the change of mechanical properties of weld parts, shielded metal are welding, one-pole and two-pole submerged arc welding were accomplished weldability on $60kg/mm^2$ quenched and tempered high strength steel. Charpy impact values of the weld metal in welded parts by SMAW and SAW were lower than those of the heat affected zone and increased in order of bond, coarsened, refined and carbon spheroidized regions in the heat affected zone. Grain size of prior austenite or M-A constituent did not significantly affect toughness of welded parts, but precipitated carbide films which forms at the grain boundaries or within matrix and volume fraction of pearilte were most important factor for toughness.

반사형 광 폴리머의 효율 안정을 위한 편광특성 분석

김은석,김남,Kim, Eun-Seok,Kim, Nam 대한전자공학회 2000 電子工學會論文誌-SD (Semiconductor and devices) Vol.37 No.7

Some polarization characteristics of reflection type photopolymer are investigated. Photopolymer on a Mylar substrate alters an incoming linearly polarized laser beam to an elliptical polarization. Due to the rotation of the polarization, the recording gratings show different diffraction efficiencies. The rotation angle is of order of 10-50% for the tested samples. It is found that the polymer layer does not changes the polarization direction but the Mylar substrate alone distorts the incoming polarization to a comparable degree. As align the polarization states of photopolymers to be parallel with a laser using a He-Ne laser(633nm), which is not sensitive to that material, it was possible to make high diffraction efficiency gratings. 광 폴리머(photopolymer)에 의한 편광 회전과 제작된 격자에서 나타나는 회절효율의 불안정을 분석하였으며, 특히 반사형 광 폴리머의 내부 복굴절(birefringence)에 의해 회절효율의 변화가 발생함을 밝혔다. 광 폴리머를 지지하고 있는 Mylar 기판(base sheet)은 고분자 물질로, 가공 중에 발생한 연신에 의해 복굴절이 발생하여 밤의 편광 상태를 회전시킴으로써 격자의 회절효율을 불안정하게 만드는 원인이 된다. Mylar 기판을 통과하는 빔의 편광 상태를 감광성이 없는 He-Ne 레이저를 사용하여 유리판 위에 접촉된 상태에서 방향을 조절하여 광원의 편광 상태와 평행하게 고정시킬 수 있었으며, 이로 인해 매우 안정적인 회절효율을 갖는 회절격자를 제작할 수 있었다.

공간 광 변조기를 이용한 홀로그래픽 스테레오그램의 제작

김은석,김남,Kim, Eun-Seok,Kim, Nam 대한전자공학회 1998 電子工學會論文誌, D Vol.d35 No.2

Holographic stereograms were made using a geometrical method easily. Becausethe conventioal sampling metod which is used in cylinder type stereograms, divide the anales of the object so it can't offer a binocular parallax effect very well, and it is also difficult to afficult to apply to the plane type stereograms. In this paper, holographic stereograms were made by use of a new method for the calculation of the sampling number(here, sampliing angles), and the TFT LCD. In order to calculate the sampling angles, geometrical method was used and 2-D images were projected onto diffuser screen through TFT LCD. Result stereorgrams which aremade by a sampling method proposed in this ppaer give a accurate binocular parallax and have a sufficient viewing zone and show that it is possible to make 3-D movies.

FCM을 이용한 3차원 영상 정보의 패턴 분할

김은석,주기세,Kim Eun-Seok,Joo Ki-See 한국정보통신학회 2006 한국정보통신학회논문지 Vol.10 No.5

본 논문은 공간 부호화 패턴들을 이용하여 3차원 얼굴 정보를 정확하게 측정하기 위하여 초기 얼굴 패턴 영상으로부터 이미지 패턴을 검출하기 위한 새로운 알고리즘을 제안한다. 획득된 영상이 불균일하거나 패턴의 경계가 명확하지 않으면 패턴을 분할하기가 어렵다. 그리고 누적된 오류로 인하여 코드화가 되지 않는 영역이 발생한다. 본 논문에서는 이러한 요인에 강하고 코드화가 잘 될 수 있도록 FCM 클러스터링 방법을 이용하였다. 패턴 분할을 위하여 클러스터는 2개, 최대 반복횟수는 100, 임계값은 0.00001로 설정하여 실험하였다. 제안된 패턴 분할 방법은 기존 방법들(Otsu, uniform error, standard deviation, Rioter and Calvard, minimum error, Lloyd)에 비해 8-20%의 분할 효율을 향상시켰다. In this thesis, to accurately measure 3D face information using the spatial encoding patterns, the new algorithm to segment the pattern images from initial face pattern image is proposed. If the obtained images is non-homogeneous texture and ambiguous boundary pattern, the pattern segmentation is very difficult. Furthermore. the non-encoded areas by accumulated error are occurred. In this thesis, the FCM(fuzzy c-means) clustering method is proposed to enhance the robust encoding and segmentation rate under non-homogeneous texture and ambiguous boundary pattern. The initial parameters for experiment such as clustering class number, maximum repetition number, and error tolerance are set with 2, 100, 0.0001 respectively. The proposed pattern segmentation method increased 8-20% segmentation rate with conventional binary segmentation methods.

A Mark Automatic Checking System to Inspect Character String on Chip

김은석,Kim, Eun-Seok The Korea Institute of Information and Commucation 2007 한국정보통신학회논문지 Vol.11 No.3

칩의 마크는 종류별로 다르고 매우 작아서 작업자가 육안 검사로 처리하기에는 매우 어려운 작업이다. 본 논문에서는 칩의 마크를 인식하여 잘못된 마크를 판별하는 마크 자동 검사 시스템에 대하여 제안한다. 불량항목을 검사하기 위해서 템플릿 매칭 방법과 다양한 불량 판별 조건을 사용한다. 그리고 불량판별 조건은 문자 ROI 명암도, 문자 ROI 매칭, 문자 명암도, 브로컨, 브렌치로 분류된다. 제안된 방법은 마크 불량 판별에 커다란 성능향상이 보임을 일련의 실험들을 통하여 보여준다. The character strings on chips and components are so tiny and numerous that it is a very difficult work for people to perform. In this paper, we propose a mark automatic checking system, which will determine whether chip is wrong-mark or not by recognizing characters on chips. Lots of faulty detection conditions and template matching methods are used to inspect the faulty mark items. The faulty detection classifies conditions as five kinds-darkness, matching, area, broken and branch. A series of experimentation show that the method proposed here can offer an effective way to determine wrong-mark on chips.

Accurate Boundary detection Algorithm for The Faulty Inspection of Bump On Chip

김은석,Kim, Eun-Seok The Korea Institute of Information and Commucation 2007 한국정보통신학회논문지 Vol.11 No.4

제안된 방법은 다른 이미지 서브트랙션 방법에 대하여 커다란 성능향상을 보임을 일련의 실험들을 통하여 보여준다. 일반적으로 수 마이크로 단위로 계측되는 반도체의 검사 정밀도를 높이기 위해서는 라인스캔 카메라가 이용된다. 그러나 불량 검사는 스캔속도와 조명조건에 매우 민감하기 때문에 정확한 경계검출 알고리즘이 필요하다. 본 논문에서는 반도체 칩의 범프 불량 검출의 정확성을 높이기 위해서 서브픽셀을 적용한 경계 검출을 제안하였다. 범프 에지는 범프 중심점에서 네 방향으로 1차 도함수에 의해서 검출되고 서브픽셀 방법으로 정확한 에지 위치를 찾는다. 그리고 범프 돌기, 범프 브리지, 범프 변색에 의해 범프 크기 가 변할 수 있기 때문에 에러를 최소화 하기 위해서 최소자승법을 이용하여 정확한 범프 경계를 구한다. 실험 결과 제안된 방법은 기존의 다른 경계 검출 알고리즘에 비하여 커다란 성능향상을 보였다. Generally, a semiconductor chip measured with a few micro units is captured by line scan camera for higher inspection accuracy. However, the faulty inspection requires an exact boundary detection algorithm, because it is very sensitive to scan speed and lighting conditions. In this paper we propose boundary detection with subpixel edge detection in order to increase the accuracy of bump faulty detection on chips. The bump edge is detected by first derivative to four directions from bump center point and the exact edge positions are searched by the subpixel method. Also, the exact bump boundary to calculate the actual bump size is computed by LSM(Least Squares Method) to minimize errors since the bump size is varied such as bump protrusion, bump bridge, and bump discoloration. Experimental results exhibit that the proposed algorithm shows large improvement comparable to the other conventional boundary detection algorithms.

영상 의학적 소견과 상반된 증상으로 내원한 요추 추간판탈출증 환자 2례

김은석,한경완,이한,정호석,이효은,조재희,김창연,Kim, Eun-Seok,Han, Kyung-Wan,Lee, Han,Jung, Ho-Suk,Lee, Hyo-Eun,Cho, Jae-Hee,Kim, Chang-Youn 척추신경추나의학회 2009 척추신경추나의학회지 Vol.4 No.2

Objective: The purpose of this study is to investigate the effects of oriental medicine conservative treatment on patients who show symptoms at the legion opposed to that shown in Magnetic Resonance Image(MRI) findings. Subject & Method: Oriental medicine treatment such as acupuncture and herbs was applied to two patients who were diagnosed as lateral herniated intervertebral disc of lumbar spine via MRI but whose pain and muscular force attenuation were shown at the opposed lower limb, for measuring its effects. Results: As for the two cases, the patients were favored in the Visual Analog Score (VAS) and the Straight leg Raising(SLR) test after the oriental medicine conservative treatment. In one case, the muscular force in the lower limb was favored. Conclusion: Based on the results in this study, oriental medicine conservative treatment might be effective on patients who show symptoms at the legion opposed to that shown in MRI findings.

홀로그래픽 스테레오그램에 관한 샘플링 이론과 관찰영역의 확대

김은석,김남,Kim, Eun-Seok,Kim, Nam 한국광학회 1996 한국광학회지 Vol.7 No.4

실물을 이용한 홀로그램과 다르게 홀로그래픽 스테레오그램은 비교적 적은 수의 2차원 영상정보를 합성하여 제작된다. 부적절한 샘플링에 의해 나타나는 영상 사이의 간섭특성을 조사하였으며 새로운 샘플링 이론을 제안하고 이를 홀로그래픽 스테레오그램 제작에 이용하였다. 또한 관찰범위를 확대하기 위한 광학 시스템을 제시하였다. 이러한 분석결과들은 일반적인 홀로그래픽 스테레오그램의 제작과 컴퓨터를 이용한 홀로그래픽 스테레오그램의 제작에 응용할 수 있다. Unlike holograms of real objects, holographic stereograms(HS) are made using a relatively small number of synthesized 2D images. The influence of aliasing artifacts caused by insufficient or improper sampling is presented, and a new sampling theory is proposed, which is used to making holographic stereograms. Also, the optical system for extension of viewing distance and viewing zone is proposed. Results of this analysis can be applied to design normal holographic stereograms and computer based holographic stereograms.

응력제거 열처리가 60kg/mm2급 조질 고장력강의 용접부 미세조직과 기계적 특성에 미치는 영향

김은석,정인상,박경채 ( O . S . Kim,I . S . Chung,K . C . Park ) 한국열처리공학회 1993 熱處理工學會誌 Vol.6 No.3

For the purpose of studying the influence of stress relieving on microstructures and mechanical properties of weld metal, manual arc welding, onepole and twopole submerged arc welding were accomplished on 60㎏/㎟ quenched and tempered high strength steel. After stress relieving, a lot of carbides were precipitated, developed and subsequently coarsened at the grain boundaries and within matrix due to multiple tempering effect in manual arc welding, resulting in deterioated toughness. Meanwhile pearlite and cementite films were spheroidized and shortened in submerged arc welding, resulting in improved considerable toughness. It was observed that main effect of stress relieving was to reduce solut supersaturation by nucleation and growth of carbide precipitates, and stress relieving led to some reduction in the yield and tensile strength but did not significantly affect elongation.