• Journal of Welding and Joining
• /
• v.19 no.6
• /
• pp.600-607
• /
• 2001

A CCD camera with a laser stripe was applied to realize the automatic weld seam tracking in GMAW. It takes relatively long time to process image on-line control using the basic Hough transformation, but it has a tendency of robustness over the noises such as spatter and arc light. For this reason. it was complemented with adaptive Hough transformation to have an on-line processing ability for scanning specific weld points. The adaptive Hough transformation was used to extract laser stripes and to obtain specific weld points. The 3-dimensional information obtained from the vision system made it possible to generate the weld torch path and to obtain the information such as width and depth of weld line. We controled the wire feeding rate using informations of weld line.

• The Bulletin of The Korean Astronomical Society
• /
• v.35 no.2
• /
• pp.28.2-28.2
• /
• 2010

We investigate star clusters in the Stephan's Quintet using Wide Field Camera 3 of the Hubble Space Telescope and three filters (F438W, F606W, F814W). Stephan's Quintet located at ~ 85 Mpc, so most star clusters are seen like point source even in HST image. We perform the Point Spread Funtion fitting photometry to find star clusters. Then we have selected 749 star cluster candidates by visual inspection. Usinng simple steallr population models (Bruzual & Charlot, 2003), we estimate ages of these star clusters. Many young star clusters found in tidal features of NGC 7318 and NGC 7319. Also star clusters in the shocked region of NGC7318 have younger age than those in NGC 7319 tidal tail. These result implies interaction which distrupt NGC 7319 first, and collision between NGC 7318 A/B occurred. In contrast, old star clusters are mainly located in NGC 7317 and in the center of other galaxies. Implications of these result will be discussed.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.11 no.5
• /
• pp.107-112
• /
• 2011

In this paper, we introduce the implementation of the security system using iris recognition. This system acquires images with infrared camera and extracts the 2D code from a infrared image which uses scale-space filtering and concavity. We examine the system by (i) extract 2D code and (ii) compare the code that stored on the server (iii) measure FAR and FRR using pattern matching. Experiment results show that the proposed method is very suitable.

• Journal of Ocean Engineering and Technology
• /
• v.23 no.1
• /
• pp.60-66
• /
• 2009

This study presents an experimental investigation of the shallow water impact of a box type structure. The analysis was done based on the video images captured by a high speed camera, the flow field obtained by PIV (Particle Image Velocimetry), and pressure measurements in the divided region. The video images showed quite good agreement with the description given by Korobkin. The PIV measurements of the velocity field provided a clear view of the flow pattern for all three stages. The pressure was measured at the bottom of the tank with strain gauge type pressure gauges. The pressure measurements showed the characteristics of divided regions.

• Journal of Technologic Dentistry
• /
• v.24 no.1
• /
• pp.73-81
• /
• 2002

Accurate acquisition of surface geometries such as machined surfaces, biological surfaces, and deformed parts have been very important technique in scientific study and engineering, expecially for system design, manufacturing and inspection. Two camera method is relatively simple with an acceptable accuracy. In this paper, a new method is studied to acquire 3D geometric data of the small object such as a die in stone model. When the devices, cameras, laser beam and object are in a perfect plane, the calculation becomes very simple with less error. But this paper shows that arbitrarily positioned system can also be used to obtain 3D data.

• Journal of Institute of Control, Robotics and Systems
• /
• v.6 no.5
• /
• pp.396-403
• /
• 2000

A thermal imaging system is implemented for the measurement and the analysis of the thermal distribution of the target objects. The main part of the system is a thermal camera in which a focal plane array typed sensor is introduced. The sensor detects the mid-range infrared spectrum of target objects and then it outputs a generic video signal which should be processed to form a frame thermal image. Here, a digital signal processor(DSP) is applied for the high speed processing of the sensor signals. The DSP controls analog-to-digital converter, performs correction algorithms and outputs the frame thermal data to frame buffers. With the frame buffers can be generated a NTSC signal and transferred the frame data to personal computer(PC) for the analysis and a monitoring of the thermal scenes. By performing the signal processing functions in the DSP the overall system achieves a simple configuration. Several experimental results indicate the performance of the overall system.

• Proceedings of the IEEK Conference
• /
• 2003.11b
• /
• pp.83-86
• /
• 2003

This paper suggests user's interface with computer by means of detecting gaze under HMD, head mounted display, environment. System is derived as follows; firstly, calibrate a camera in HMD, which determines geometrical relationship between monitor and captured image. Second, detect the center of pupil using algorithm of the center of mass and represent a gazing position on the computer screen. If user blinks or stares at a certain position for a while, message is sent to computer. Experimental results show the center of mass is robust against glint effects, and detecting error was 7.1%. and 4.85% in vertical and horizontal direction, respectively. To adjust detailed movement of a mouse takes 0.8 sec more. The 98% of blinking is detected successfully and 94% of clicking detection is resulted.

• Proceedings of the KIEE Conference
• /
• 2006.04a
• /
• pp.15-17
• /
• 2006

This paper presents a new global intensity compensation method for extracting moving object in a visual surveillance system by compensating time variant intensity changes of background region. The method that compensates a little changes of intensity due to time variant illumination change and automatic gain control of camera is called global intensity compensation. The proposed method expresses global intensity change with a mapping table to describe complex form of intensity change while the previous method models this global intensity change with a simple function as a straight line. The proposed method builds the mapping table by calculating the cross histogram between two images and then by selecting an initial point for generating the mapping table by using Hough transform applied to the cross histogram image. Then starting from the initial point, the mapping table is generated according to the proposed algorithm based on the assumption that reflects the characteristic of global intensity change. Experimental results show that the proposed method makes the compensation error much smaller than the previous GIC method

• Proceedings of the KIEE Conference
• /
• 2008.07a
• /
• pp.5-6
• /
• 2008

차단기, 개폐기, 배전반과 같은 전력기기에 대한 성능시험시, 전압과 전류, 제어신호를 측정하고, 필요한 경우 고속카메라를 이용해 시험장면을 촬영한 다음, 이들을 종합적으로 분석하여 시험결과를 판정한다. 이때, 대부분 개별 시스템으로 전압-전류 시험파형과 시험영상을 측정하고 분석하기 때문에, 시간 동기화가 불가능하여 시험현상이나 시료동작특성 분석에 많은 어려움이 있다. 따라서 개별 시스템으로 측정한 신호를 동기 시켜 동시에 분석할 수 있는 프로그램이 있다면, 시험결과 판정뿐만 아니라 시험 중에 발생하는 전기적 과도현상이나 시료의 동작특성분석에 많은 도움이 될 것이다. 이러한 목적을 위해, PT&T에서는 측정시스템과 고속카메라를 이용하여 측정한 전압-전류 시험파형과 시험영상을 동기 시켜 동시에 분석할 수 있는 프로그램인 Dual Viewer를 개발하였다. 본 논문에서는 Dual Viewer에 대한 기능과 특징에 대해 소개하고자 한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
• /
• 2015.07a
• /
• pp.542-543
• /
• 2015

본 논문에서는 차량에 설치된 스테레오 카메라를 이용하여 객체 후보를 검출하는 기법을 제안한다. 단일 카메라를 이용하면 색상 정보만을 획득할 수 있지만 스테레오 카메라를 이용하면 추가적으로 깊이 영상(depth image)을 획득할 수 있다. 깊이 정보를 이용하면 카메라의 주변 환경을 재구성 할 수 있으며, 객체 후보 검출의 성능을 향상 시킬 수 있다. 스테레오 매칭(Stereo matching)을 통해 획득한 깊이 영상을 열 단위 분석을 통해 객체로 판단되는 영역을 검출한다. 검출한 영역 경계 부근의 오류를 줄이기 위해 밝기 차를 분석한다. 실험을 통해 제안하는 시스템이 효과적으로 객체 후보를 검출하는 것을 확인하였다.