• 한국가시화정보학회:학술대회논문집
• /
• 한국가시화정보학회 2005년도 추계학술대회 논문집
• /
• pp.40-45
• /
• 2005

Velocity and density distributions of a high-speed and initial $CO_{2}$ jet flow have been analyzed simultaneously by a developed three-dimensional digital speckle tomography and a particle image velocimetry(PIV). Three high-speed cameras have been used for tomography and PIV since a shape of a nozzle for the jet flow is asymmetric and the initial flow is fast and unsteady, The speckle movements between no flow and $CO_{2}$ jet flow have been obtained by a cross-correlation tracking method so that those distances can be transferred to deflection angles of laser rays for density gradients. The three-dimensional density fields for the high-speed $CO_{2}$ jet flow have been reconstructed from the deflection angles by a real-time tomography method and the two-dimensional velocity fields have been calculated by a PIV method simultaneously and instantaneously.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2009년도 9th International Meeting on Information Display
• /
• pp.1341-1344
• /
• 2009

A novel method to control the viewing direction by moving aperture location in 4-f illumination optics to control light direction is proposed. Based on integral imaging principle, the relayed point light sources by 4-f optics are modulated by a spatial light modulator, displaying three-dimensional images. In the proposed method, we locate the aperture, which acts as a band pass filter, around an optic axis to control the light direction. Resultantly, assuming that we know the viewer position by a tracking system, we can display appropriate three-dimensional images over large viewing angle.

• Journal of Welding and Joining
• /
• 제22권6호
• /
• pp.43-49
• /
• 2004

In this study, a visual sensor system which can detect I-butt weld joint with height variation and includes a seam tracking algorithm was investigated. Three-dimensional position of an object can be acquired by using the method of distance measurement, i.e., an optical trigonometry which results from the spatial relations between the camera, the object and the structured light by a visible laser. Effects of laser intensity and iris number for the image quality as well as object material were investigated for the optical system design. For the image processing, a region of interest is defined from the whole image and a line image of laser is drew by using the gray level difference in the image. From the drew laser line, the weld joint can be recognized in searching the biggest point position calculated from the central difference method. Through a series of welding experiments, a good tracking performance was confirmed under GMA welding.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1992년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 19-21 Oct. 1992
• /
• pp.541-547
• /
• 1992

The phased array antenna has the ability to perform adaptive sampling by directing the radar beam without inertia in any direction. The adaptive sampling capability of the phased array antenna allows each sampling time interval to be varied for each target, depending on the acceleration of each target at any time. In this paper we design a three-dimensional adaptive tracking algorithm for the phased array radar system with a given set of measurement parameters. The tracking algorithm avoids taking unnecessarily frequent samples, while keeping the angular prediction error within a fraction of antenna beamwidth so that the probability of detection will not be degraded during a track update illuminations. In our algorithm, the target model and the sampling rate are selected depending on the target range and the target maneuver status which is determined by a maneuver detector. A detailed simulation is conducted to test the validity of our tracking algorithm for encounter geometries under various conditions of maneuver.

• International journal of advanced smart convergence
• /
• 제5권4호
• /
• pp.57-65
• /
• 2016

This paper aims to improve the quality of cultural experience by providing a three - dimensional guide service that enables users to experience themselves without additional guides and cultural commentators using the latest mobile IT technology to enhance understanding of cultural heritage. In this paper, we propose a method of constructing cultural contents based on location information such as user / cultural heritage using markerless tracking based augmented reality and GPS. We use marker detection technology and markerless tracking technology to recognize smart augmented reality object accurately and accurate recognition according to the state of cultural heritage, and also use Android's Google map to locate the user. The purpose of this paper is to produce content for introducing cultural heritage using GPS and augmented reality based on Android. It can be used in combination with various objects beyond the limitation of existing augmented reality contents.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제3권1호
• /
• pp.108-118
• /
• 2009

In this paper we develop an indoor location tracking system and its 3D tracking monitoring viewer, viz., 3D Navigation Viewer (3DNV). We focus on the integration of an indoor location tracking system with the Virtual Reality Modeling Language (VRML), to facilitate a representation of the user's spatial information in virtual indoor environments that is synchronized with the physical location environment. The developed indoor location tracking system employs beacons as active transmitters, and a listener as a passive receiver. The distance information calculated from the difference speeds of RF and Ultrasonic signals is exploited, to determine the user's physical location. This is essential in supporting third parties like doctors and caregivers in identifying the activities and status of a particular individual via 3DNV. 3DNV serves as a unified user interface for an indoor location tracking system, showing the viewpoint and position of the target in virtual indoor environments. It was implemented using VRML, to provide an actual real time visualization of the target's spatial information.

• 한국지능시스템학회:학술대회논문집
• /
• 한국퍼지및지능시스템학회 2001년도 춘계학술대회 학술발표 논문집
• /
• pp.126-130
• /
• 2001

In this paper, we propose the design methodology of target tracking system using fuzzy basis function expansion (FBFE) based on virus evolutionary genetic algorithm(VEGA). In general, the objective of target tracking is to estimate the future trajectory of the target based on the past position of the target obtained from the sensor. In the conventional and mathematical nonlinear filtering method such as extended Kalman filter (EKF), the performance of the system may be deteriorated in highly nonlinear situation. To resolve these problems of nonlinear filtering technique, by appling artificial intelligent technique to the tracking control of moving targets, we combine the advantages of both traditional and intelligent control technique. In the proposed method, after composing training datum from the parameters of extended Kalman filter, by combining FBFE, which has the strong ability for the approximation, with VEGA, which prevent GA from converging prematurely in the case of lack of genetic diversity of population, and by identifying the parameters and rule numbers of fuzzy basis function simultaneously, we can reduce the tracking error of EKF. Finally, the proposed method is applied to three dimensional tracking problem, and the simulation results shows that the tracking performance is improved by the proposed method.

• 대한의용생체공학회:의공학회지
• /
• 제9권2호
• /
• pp.153-158
• /
• 1988

A three-dimensional surface is reconstructed from contour information as identified on two-dimensional computed tomographic slices. Gradient operator with curvature constraint would be applied to extract the contour automatically, and backtracking is also adopted to reduce the tracking error. The surface between the consecutive slice is efficiently reconstructed using a triangular surface tiles. Hidden surface elimination, shading and parallel projection of the reconstructed surface are provied on the display screen.

• 한국정보통신학회논문지
• /
• 제11권3호
• /
• pp.627-633
• /
• 2007

이 논문은 선적 및 하역 작업을 위해 겐추리 크레인으로 들어오는 컨테이너 트레일러의 위치 추적 시스템에 대하여 기술한다. 위치 추적 시스템은 트레일러가 겐추리 크레인에 접근하였을 때 트레일러의 정지 지점을 운전자에게 알려준다. 위치 측정 센서는 RF 신호와 초음파 방식을 채택한 크리켓 mote 모듈을 사용하였다. 실시간 전송을 위해 위치 측정 주기를 단축하였으며 삼각측량 방법에 따른 3 차원 위치 계산식과 환경적 요인에 의한 거리 측정 오류 감소 방법을 제시하였다. 측정된 위치는 블루투스 통신을 통해 주기적으로 운전자 앞의 PDA (Personal Digital Assistant)에 전송된다. 실내외 테스트 결과 위치 오류는 3 cm 이내로 개선되었으며 위치 측정 표시 주기는 평균 0.5초였다.

• 수산해양기술연구
• /
• 제40권1호
• /
• pp.78-85
• /
• 2004

SSBL ${\circ}$ 핑거동기 바이오텔레메터리 방식과 시스템을 사용하여 핑거를 부착한 어류의 행동 추적실험을 실시하였다. 이상의 연구 성과를 정리하면 다음과 같다. 1) 수조의 추적실험에서는 어류의 대략적인 행동을 관측할 수 있기 때문에 어류의 이동경로의 계측치와 대체적인 관측치를 비교하면서 어류의 이동경로와 속도 등을 조사하였다. 계측한 잉어의 행동이 관측치와 대체적으로 일치하였으며, 3차원으로 추적이 가능하였다. 잉어의 평균 이동속도는 11.2cm/s로 거의 적당한 결과를 얻을 수 있었다. 2) 계류장의 추적실험에서는 상하, 좌우 방향으로 회전가능한 지지 파이프에 수파기를 설치하고 수파기를 회전시키며 자연상태에서 어류의 이동경로와 속도 등을 조사하였다. 방어의 행동이 상세하게 추적 가능함을 확인할 수 있었으며, 방어의 평균이동 속도는 439cm/s이었다. 이상에 의해 본 연구에서 개발한 SSBL ${\circ}$ 핑거동기 바이오텔레메터리 방식에 의하면 수신계의 고도화만으로도 핑거를 부착한 어류의 상세한 행동추적 이 가능함을 확인할 수 있었다.