• 한국가시화정보학회:학술대회논문집
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• 한국가시화정보학회 2006년도 추계학술대회 논문집
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• pp.1-6
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• 2006

Single-Camera Stereoscopic Vision three-dimensional measurement system has been developed based upon 30-PTV algorithm. The system consists of one camera $(1k\times1k)$ and a host computer. To attain three-dimensional measurements a plate having stereo holes has been installed inside of the lens system. Three-dimensional measurements was successfully attained by adopting the conventional 30-PTV camera calibration methods. As applications of the constructed measurement system, a water droplet mixed with alcohol was constructed on a transparent plastic plate with the contacted fluid diameter 4mm, and the particles motions inside of the droplet have been investigated with the constructed measurement system. The measurement uncertainty of the constructed system was 0.04mm, 0.04mm and 0.09mm for X, Y and Z coordinates.

• 패션비즈니스
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• 제17권1호
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• pp.30-41
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• 2013

Augmented reality techniques have been increasingly employed in the textile and fashion industry as well as computer graphics sectors. Three-dimensional virtual clothing CAD systems have also been widely used in the textile industries and academic institutes. Motion tracking techniques are grafted together in the 3D and augmented reality techniques in order to develop the virtual three-dimensional clothing and fitting systems in the fashion and textile industry sectors. In this study, three-dimensional virtual clothing sample has been prepared using a 3D virtual clothing CAD along with a 3D scanning and reconstruction system. Motion of the user has been captured through an RGB-D sensor system, and the virtual clothing fitted on the user's body is allowed to move along with the captured motion flow of the user. Acutal fabric specimens are selected for the material characterization. This study is a primary step toward building a comprehensive system for the user to experience interactively virtual clothing under real environment.

• International Journal of Precision Engineering and Manufacturing
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• 제8권2호
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• pp.59-63
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• 2007

We propose a controller design analysis for a cross-coupling control system, which is essential for achieving high contouring accuracy in multi-axis CNC systems. The proposed analysis combines three axial controllers for each individual feed drive system together with a cross-coupling controller at the beginning of the design stage in an integrated manner. These two types of controllers used to be separately designed and analyzed since they have different control objectives. The proposed scheme is based on a mathematical formulation of a three-dimensional contour error model and includes a stability analysis for the overall control system and a performance analysis in terms of contouring and tracking accuracy at steady state. A computer simulation was used to demonstrate the validity of the proposed methodology. The performance variation was investigated under different operating conditions and controller gains, and a design range was elicited that met the given performance specifications. The results provide basic guidelines in systematic and comprehensive controller designs for multi-axis CNC systems. A cross-coupling control system was also implemented on a PC-based three-axis CNC testbed, and the experimental results confirmed the usefulness of the proposed control system in terms of contouring accuracy.

• 한국분무공학회지
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• 제6권4호
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• pp.31-38
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• 2001

The Holographic Particle Velocimetry system can be a promising optical tool for the measurements of three dimensional particle velocities. In this study, the holographic panicle velocimetry system was used to measure the sizes and velocities of droplets formed by a commercial full cone spray nozzle. Uncertainty analysis was performed to identify the sources of all relevant errors and to evaluate their magnitude. The droplet velocities ranged from 10.3 to 13.3 m/s with average uncertainty of ${\pm}1.6m/s$, which is ${\pm}14%$ of the mean droplet velocity. Compared with relatively small uncertainties of velocity components in the normal direction to the optical axis, the uncertainty of the optical axis component is ${\pm}3.6m/s$. This is due to the long depth of field of droplet images in the optical axis, which is inherent feature of holographic system using forward-scattering object wave of particles.

• Applied Science and Convergence Technology
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• 제25권5호
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• pp.98-102
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• 2016

The level set method has recently become popular in the simulation of semiconductor processes such as etching, deposition and photolithography, as it is a highly robust and accurate computational technique for tracking moving interfaces. In this research, full three-dimensional level set simulation has been developed for the investigation of focused ion beam processing. Especially, focused ion beam induced nanodot formation was investigated with the consideration of three-dimensional distribution of redeposition particles which were obtained by Monte-Carlo simulation. Experimental validations were carried out with the nanodots that were fabricated using focused $Ga^+$ beams on Silicon substrate. Detailed description of level set simulation and characteristics of nanodot formation will be discussed in detail as well as surface propagation under focused ion beam bombardment.

• 한국정밀공학회지
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• 제21권5호
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• pp.83-83
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• 2004

The analysis of relative pose(position and rotation) between stereo cameras is very important to determine the solution that provides three-dimensional information for an arbitrary moving target with respect to robot-end. In the space of free camera-model, the rotational parameters act on non-linear factors acquiring a kinematical solution. In this paper the general solution of active stereo that gives a three-dimensional pose of moving object is presented. The focus is to achieve a derivation of linear equation between a robot′s end and active stereo cameras. The equation is consistently derived from the vector of quaternion space. The calibration of cameras is also derived in this space. Computer simulation and the results of error-sensitivity demonstrate the successful operation of the solution. The suggested solution can also be applied to the more complex real time tracking and quite general and are applicable in various stereo fields.

• 한국정밀공학회지
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• 제21권5호
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• pp.89-90
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• 2004

The analysis of relative pose(position and rotation) between stereo cameras is very important to determine the solution that provides three-dimensional information for an arbitrary moving target with respect to robot-end. In the space of free camera-model, the rotational parameters act on non-linear factors acquiring a kinematical solution. In this paper the general solution of active stereo that gives a three-dimensional pose of moving object is presented. The focus is to achieve a derivation of linear equation between a robot's end and active stereo cameras. The equation is consistently derived from the vector of quaternion space. The calibration of cameras is also derived in this space. Computer simulation and the results of error-sensitivity demonstrate the successful operation of the solution. The suggested solution can also be applied to the more complex real time tracking and quite general and are applicable in various stereo fields.

• Journal of Korean Dental Science
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• 제15권2호
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• pp.166-171
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• 2022

This case report describes a dynamic digital esthetic rehabilitation procedure that integrates a new three-dimensional augmented reality (3D-AR) technique to treat a patient with multiple missing anterior teeth. The prostheses were designed using computer-aided design (CAD) software and virtually trialed using static and dynamic visualization methods. In the static method, the prostheses were visualized by integrating the CAD model with a 3D face scan of the patient. For the dynamic method, the 3D-AR application was used for real-time tracking and projection of the CAD prostheses in the patient's mouth. Results of a quick survey on patient satisfaction with the two visualization methods showed that the patient felt more satisfied with the dynamic visualization method because it allowed him to observe the prostheses directly on his face and be more proactive in the treatment process.

• 한국지능시스템학회논문지
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• 제21권5호
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• pp.537-542
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• 2011

거울 신경 세포는 동물이 어떤 동작을 할 때와 그 동물이 다른 동물의 동일한 동작을 하는 것을 관찰 할 때, 똑같은 세포 발화를 하는 신경세포이다. 본 논문에서는 거울 신경 세포의 발화 원리를 이용하여 비슷한 방법으로 보이지 않는 부분에 대한 객체의 움직임을 추적하는 방법을 3차원 재구축 방법을 통해 제안한다. 거울 신경 세포 시스템과 같은 발화 원리를 통해 의도 인지 시스템을 구축하기 위해, 스테레오 카메라를 통해 획득한 두 개의 이미지 데이터를 통해 깊이 정보를 계산하여 3차원으로 재구축한다. 3차원 재구축을 통해 만들어진 이미지 데이터를 옵티컬 플로우를 사용하여 3차원 이미지에서 객체의 움직임 방향을 추정한다. Estimation 알고리즘인 칼만 필터를 사용하여 객체의 움직임 추정을 잡음에 강인하게 한다. 객체의 움직임 추정을 통하여 객체의 움직임에 따라 구축된 이미지 데이터를 히스토리화 하여 데이터를 저장한다. 객체의 일부분 혹은 전체가 다른 물체로 인해 가려져 스테레오 카메라 시야에서 사라졌을 때, 과거에 저장된 히스토리로 부터 데이터를 가져와 가려진 부분에 대한 객체의 원래의 모습을 복원한다. 이 복원을 통하여 움직임 추정을 한다.

• Journal of information and communication convergence engineering
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• 제12권4호
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• pp.208-214
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• 2014

In this paper, in order to solve the problems of a narrow viewing angle and the flip effect in a three-dimensional (3D) integral imaging display, we propose an improved system by using an eye tracking method based on the Kinect sensor. In the proposed method, we introduce two types of calibration processes. First process is to perform the calibration between two cameras within Kinect sensor to collect specific 3D information. Second process is to use a space calibration for the coordinate conversion between the Kinect sensor and the coordinate system of the display panel. Our calibration processes can provide the improved performance of estimation for 3D position of the observer's eyes and generate elemental images in real-time speed based on the estimated position. To show the usefulness of the proposed method, we implement an integral imaging display system using the eye tracking process based on our calibration processes and carry out the preliminary experiments by measuring the viewing angle and flipping effect for the reconstructed 3D images. The experimental results reveal that the proposed method extended the viewing angles and removed the flipping images compared with the conventional system.