아스페르질루스종으로 오진된 수술 후 남겨진 폐내 거즈 -1예 보고-

오재윤,신화균,원용순,이재욱,양진성 대한흉부외과학회 2007 Journal of Chest Surgery (J Chest Surg) Vol.40 No.8

55세 남자환자가 간헐적인 기침, 피 섞인 가래를 주소로 입원하였다. 35년 전 그는 군대에서 결핵으로 인해 우측 상엽절제술을 받았다. 흉부 컴퓨터 단층촬영에서는 우측폐의 내부에 공기-초승달 징후를 포함하고 있는 종괴가 보였다. 우측상엽에 5×7 cm 크기의 종괴가 있었고, 경계가 분명하였다. 제거한 종괴를 살펴보니 이물질(거즈)을 포함하고 있었다. 저자들은 아스페르질루스종으로 오진된 폐내 잔존거즈를 체험하였기에 보고하는 바이다.

순차적 레이블링을 이용한 지문 융선 특징 검출

오재윤,엄재원,최태영 대한전자공학회 2003 電子工學會論文誌-SP (Signal processing) Vol.40 No.3

본 논문에서는 세선화 지문 영상의 순차적 레이블링을 이용하여 위치 이동, 크기 변화 그리고 회전에 무관한 새로운 지문 융선 특징 검출 알고리즘을 제안한다. 제안한 알고리즘은 먼저 지문의 중심점을 지나는 수직선을 이용하여 세선화 지문 영상의 융선을 순차적으로 레이블링 한다. 그리고 레이블링한 개개의 융선들로부터 특징을 검출한다 검출하는 특징은 융선의 종류와 융선에 존재하는 특징점의 융선 각도이다. 이러한 방법을 이용하여 지문 융선의 특징을 검출하면, 지문을 이루고 있는 여러 융선들의 종류를 알 수 있고, 각 융선에 존재하는 특징점의 종류 및 이들의 각도를 알 수 있다. 두 개의 세선화 지문 영상을 이용하여 실험한 결과, 제안하는 알고리즘이 위치 이동, 크기 변화 그리고 회전에 무관한 지문 융선 특징을 검출함을 확인하였다. A novel fingerprint ridge feature extraction using sequential labeling of thinned fingerprint image is proposed, which is invariant to position translation, scaling, and rotation. the proposed algorithm labels ridges of thinned fingerprint image sequentially using vertical line that goes through fingerprint core point. Then, we extract a feature from each labeled ridge and the extraction process is based on the type fo the ridge and a minutiae ridge angle in the ridge. The feature extracted through this process enables us to find out the kind of various minutiae and minutiae angle. As a result of the experiment using two thinned fingerprint images, we finally confirm that proposed algorithm is not related to position translation, scaling, and rotation.

안정된 일반형 예측 제어기의 강인한 제어기 설계

오재윤,주진만,박진배 제어로봇시스템학회 1995 제어로봇시스템학회 국내학술대회 논문집 Vol.1 No.2

중력장에서 두개의 탄성팔을 가지는 로보트의 모델링

오재윤 대한기계학회 1992 대한기계학회논문집 Vol.16 No.6

본 연구에서는 두개의 팔을 가지는 실험용 로보트를 모델링 하기위해 사용된 기법들을 제시한다. 로보트는 수직 평면상에서 움직이므로 중력의 영향을 받는다. 그리고 두팔은 모두 탄성을 가진다. 이 로보트는 탄성 멤버들을 가지는 로보트의 여 러 제어기법들을 연구하기위해 만들어졌다. 시스템의 특성들은 아주 유연한 멤버들 을 가지게끔 정해진다.이것은 제어를 위해 쓰이는 전자부품들에 요구되는 밴드폭을 제안하고, 탄성이 크고 빠른 로보트에서 관찰 되어지는 유연한 운동들을 흉내낸다. This paper presents techniques used to model a two arm experimental robot. Both arms are compliant and the robot operates in a vertical plane and is therefore influenced by gravity. The robot is being built to study different control strategies for robots containing compliant members. The system is built with extremely flexible members. This limits the required bandwidth of the control electronics, and mimics the flexible motions that are observed for stiffer faster robots. The objective of this paper is to develop a reduced order model of the robot system and to experimentally validate the model. Validation requires that the model includes gravitational effects. Therefore, an assumed modes model is developed which facilitates modeling of gravitational effects. In order to select the order and mode shapes for the model, an analytical solution is derived for a linearized continuous model. This is compared to the assumed modes model to determine the number of mode shapes needed to model the system. The final model, which includes shortening effects, correlates very well with experimental results.

수직평면상에서 작동하는 유연한 단일링크 매니퓰레이터의 모델링에 관한 연구

吳在倫 全北大學校 1994 論文集 Vol.38 No.-

This paper presents a technique to model a manipulator which has a flexible link and moves in a vertical plane, and experimentally validates the model. The flexible link is modeled as a Euler-Bernoulli Beam. Elastic deformation of the flexible link is represented using the assumed modes method. A comparison function which satisfies geometric and natural boundary conditions of a cantilever beam with end mass is developed and used as an assumed mode shape. Lagrange's equation is utilized for the development of a discretized model. This paper presents a simple technique to improve the correctness of the developed model. The final model including the shortening effect correlatives very well with experimental results. The free body motion simulation shows that two assumed modes for the representation of the elastic deformation is proper in points of model size and correctness.

두개의 탄성링크를 가지는 Manipulator의 제어

吳在倫 全北大學校 1993 論文集 Vol.36 No.-

This paper develops a control algorithm for end point position control of an elastic two-link manipulator. first, an algorithm is developed to solve for the state variables as a function of end point position. This is used to determine a set of target state variables. A control algorithm is developed using a linear quadratic optimal control technique on an infinite time interval with the prescribed degrees of stability method to control the movement of the endpoint from a specified initial end point position to a specified terminal endpoint position. For the system dynamic equations, second order nonlinear differential equations including the shortening effect are linearized with respect to the terminal position and are put into first order. The simulation shows that the developed control algorithm results in effective end effector control with short response time and little overshoot. Also, the simulation shows that the results with one and two flexible modes for each arm have small differences in the early stage of the endpoint control but the results are almost identical later in the simulation.

주사선 알고리즘을 이용한 시뮬레이트된 방사선 사진에서 교차점 계산을 위한 기법의 개발

오재윤 전북대학교 공업기술연구소 1992 工學硏究 Vol.23 No.-

This paper develops a technique for efficiently computing the intersection points between rays and an object in a simulated radiograph. This technique allows interactive calculation of simulated radiographs for very complex parts. It needs a geometric model of a part which is approximated by a bounding surface made up of flat triangular polygons. Since rays have a point source, a perspective transformation is applied to convert the point source problem to one that has parallel rays. This permits to use a scan-line algorithm which utilizes the coherence of the grid of rays for the intersection calculations. The efficiency of the technique is shown by comparing compute time of the intersection calculations to a commercial software that computes each ray intersection independently.

대형트럭 승객거동과 상해치 해석을 위한 유한요소모델의 개발

오재윤,김학덕,송주현,O, Jae-Yun,Kim, Hak-Deok,Song, Ju-Hyeon 대한기계학회 2002 大韓機械學會論文集A Vol.26 No.8

This paper develops a finite element model for studying the occupant behavior and injury cofficients of a large-sized cab-over type truck. Since it does not have a room to absorb collision energy and deformation in front of the passenger compartment the deformation is directly transmitted to the passenger compartment. Moreover, since its steering column is attached on the frame, severe deformation of the frame directly affects on the steering wheel's movement. Therefore, if the occupant behavior and injury coefficients analysis is performed using a finite element model developed based on a sled test, it is very difficult to expect acquiring satisfactory results. Thus, the finite element model developing in this paper is based on the frontal crash test in order to overcome the inherent problems of the sled test based model commonly used in the passenger car. The occupant behavior and injury coefficients analysis is performed using PAM-CRASH installed in super-computer SP2. In order to validate the reliability of the developed finite element model, a frontal crash test is carried out according to a test method used fur developing truck occupant's secondary safety system in european community and japan. That is, test vehicle's collision direction is vertical to the rigid barrier and collision velocity is 45kph. Thus, measured vehicle pulses at the lower parts of the left and right B-pilla., dummy chest and head deceleration profiles, HIC(head injury criterial) and CA(chest acceleration) values, and dummy behavior from the frontal crash test are compared to the analysis results to validate reliability of the developed model.

예견 능동 현가시스템에 관한 연구

吳在倫 全北大學校 1996 論文集 Vol.41 No.-

This paper developes a half-car model with a preview type active suspension system. The developed model is study the effects of the preview type active suspension on vehicle ride. A control law for the preview type active suspension system is developed using the full state feedback linear optimal control technique. The preview is performed through a virtual axle locating in front of the front axle. The previewd road information is conveyed to the front and rear axles with a time delay. The time delay between axles is approximated using Pade approximation technique. The developed active suspension system is compared with three different suspension systems(① passive ② active without a preview ③ active with a wheelbase preview). The the active suspension systems have a much better performance in the dynamic responses such as suspension working space, dynamic tire deflection and vertical motion of sprung and unsprung masses than the passive one, and the developed suspension has a better performance than the other active ones. These results are reconfirmed when a bump type road disturbance is encountered.

시뮬레이트된 방사선 사진에서 엑스선과 물체의 교차점 계산을 위한 효율적인 알고리즘의 개발

오재윤,O, Jae-Yun 한국정밀공학회 1992 한국정밀공학회지 Vol. No.

This paper develops an algorithm for efficiently computing the intersection points between rays and an object in a simulated radiograph. This algorithm allows interactive calculation of simulated radiographs for very complex parts. It needs a geometric model of a part which is approximated by a bounding surface made up of flat triangular polygons. Since rays have a point source, a perspective transformation is applied to convert the point source problem to one that has parallel rays. This permits to use a scan-line algorithm which utilizes the coherence of the grid of rays for the intersection calculations. The efficiency of the algorithm is shown by comparing compute time of the intersection calculations to a commercial software that computes each ray intersection independently.