• 한국분무공학회지
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• 제21권1호
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• pp.13-19
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• 2016

Atmospheric spray characteristics were experimentally compared between liquid-gas and liquid-liquid sprays of a pintle injector. In order to study spray characteristics, water and air were used as the simulants and the visualization technic was adopted. Spray images were acquired by using a backlight method by a high-resolution CMOS camera. As a result, when the pintle opening distance increased, liquid sheets became unstabled and fluttering droplets increased. In the liquid-gas case, the breakup performance increased as the pressure of gas injected from the annular orifice increased. In the liquid-liquid case, atomization efficiency decreased as the pressure of liquid injected from the annular orifice increased. Spray angles presented a similar trend between two cases. At the same momentum ratio, the spray angle of liquid-liquid case was lower than the angle of liquid-gas case.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2004년도 추계학술발표회 논문집
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• pp.189-195
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• 2004

The purpose of this study was to establish the accuracy of the industral photogrammetry system constructed with INCA2 metric camera and V-STARS system on steel box girder measurement under industrial measurement condition. The objective of the measurement was to determine the distances of plane to plane or plane to libs, precise positions of the bolt holes and angles of the plane to plane on the steel box girder using coded targets, tape targets, edge targets and target adapters. The measurement undertaken has shown that industrial photogrammetry method were a very accurate and more importantly were produced quietly to measure the steel box girder.

• International Journal of Control, Automation, and Systems
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• 제6권4호
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• pp.607-612
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• 2008

This paper proposes a robot visual servo approach based on image appearance and a wavelet function neural network. The inputs of the wavelet neural network are changes of image features or the elements of image appearance vector, and the outputs are changes of robot joint angles. Image appearance vector is calculated by using eigen subspace transform algorithm. The proposed approach does not need a priori knowledge of the robot kinematics, hand-eye geometry and camera models. The experiment results on a real robot system show that the proposed method is practical and simple.

• 한국광학회지
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• 제17권6호
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• pp.525-531
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• 2006

3차원 물체의 합성된 컴퓨터 형성 홀로그램(CGH)을 새로운 형태의 3차원 좌표변환 기술을 사용하여 제작하였다. 제작될 3차원 물체는 CCD 카메라를 사용하여 시야각도(viewing angle)를 변화시키면서 여러개의 영상으로 기록하였다. 이렇게 얻어진 영상 데이터는 2차원 복소 매트릭스를 사용하여 수학적인 방법으로 계산되고, 최종적으로 합성된 3차원 CGH로 부호화하였다.

• 음성과학
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• 제11권4호
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• pp.29-42
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• 2004

This paper presents an implementation of real-time speaker localization using audio-visual information. Four channels of microphone signals are processed to detect vertical as well as horizontal speaker positions. At first short-time average magnitude difference function(AMDF) signals are used to determine whether the microphone signals are human voices or not. And then the orientation and distance information of the sound sources can be obtained through interaural time difference. Finally visual information by a camera helps get finer tuning of the angles to speaker. Experimental results of the real-time localization system show that the performance improves to 99.6% compared to the rate of 88.8% when only the audio information is used.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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• pp.903-906
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• 1993

Lipreading through visual processing techniques help provide some useful systems for the hearing impaired to learn communication assistance. This paper proposes a method to understand spoken words by using visual images taken by a camera with a video-digitizer. The image is processed to obtain the contours of lip, which is approximated into a hexagon. The pattern lists, consisting of lengths and angles of hexagon, are compared and computed to get the fuzzy similarity between two lists. By similarity matching, the mouth shape is recognized as the one which has the pronounced voice. Some experiments, exemplified by recognition of the Japanese vowels, are given to show feasibilities of this method.

• 대한공간정보학회지
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• 제10권5호
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• pp.67-74
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• 2002

The geometriccorrection of a satellite imagery is performed by making a systematic correction with satellite ephemerides and attitude angles followed by employing the Ground Control Points (GCSs) or Digital Elevation Models (DEMs). In a remote area or an inaccessible area, however, GCPs are unavailable to be surveyed and thus they can be obtained only by reading maps, which are not accurate in reality. In this study, we performed the systematic correction process to the inaccessible area and the precise geometric correction process to the adjacent accessible area by using GCPs. Then we analyzed the correlation between the two geo-referenced Korea Multiurpose Satellite (KOMPSAT-1 EOC) images. A new geometrical correction for the inaccessible area imagery is achieved by applying the correlation to the inaccessibleimagery. By employing this new method, the accuracy of the inaccessible area imagery is significantly improved absolutely and relatively.

• 동력기계공학회지
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• 제6권1호
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• pp.96-101
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• 2002

In this paper, we address the problem of controlling an end-effector to track and grab a moving target using the visual servoing technique. A visual servo mechanism based on the image-based servoing principle, is proposed by using visual feedback to control an end-effector without calibrated robot and camera models. Firstly, we consider the control problem as a nonlinear least squares optimization and update the joint angles through the Taylor Series Expansion. And to track a moving target in real time, the Jacobian estimation scheme(Dynamic Broyden's Method) is used to estimate the combined robot and image Jacobian. Using this algorithm, we can drive the objective function value to a neighborhood of zero. To show the effectiveness of the proposed algorithm, simulation results for a six degree of freedom robot are presented.

• 영미문화
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• 제9권1호
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• pp.71-90
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• 2009

David Harris argues that mass media suppress counter-hegemonic factors in order to reach audience. According to Harris's theory, the success of the film "Tess" depends on its effective adaptation from Thomas Hardy's novel Tess of the D'Urbervilles (1891). Tess (1979), directed by Roman Polansky, casting Nastassia Kinski for Tess, was acclaimed as a professional and commercial success, awarded with various prizes. Hardy's aim at criticizing Victorian English social and moral standard through Tess appears obscure in Polansky's film which focuses on the aesthetics of human body and capital. Polanski's Tess with urban white beauty does not emerge victimized by poverty, which the late twentieth century audience under the capitalist umbrella may abhor. To examine his use of music, sound effect, visual images by means of camera operation—angles, distances, close-ups and frequent movements—light and color, and mythic elements in the film, show Polansky's sharp perception of his contemporary audience's desire and conscientious work upon it.

• International Journal of Naval Architecture and Ocean Engineering
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• 제13권1호
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• pp.877-888
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• 2021

The water entry behaviors of projectiles with different cone-headed angles were studied numerically, experimentally and theoretically, mainly focusing on the hydrodynamic impact in the initial stage. Based on MMALE algorithm, it was proposed a formula of impact deceleration, which relied on the initial entry velocity and cone-headed angle. Meanwhile, in order to verify the validity of the simulation model, experiments using accelerometer and high-speed camera were carried out, and their results were in a good agreement with simulation results. Also, theoretical calculation results of cavity diameter were compared with experiments and simulation results. It was observed that the simulation method had a good reliability, which would make forecast on impact deceleration in an engineering project.