• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2014년도 하계학술대회
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• pp.133-134
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• 2014

Conventional stereo matching algorithms fail when they deal with anaglyph image as its input because anaglyph image does not have similar intensity on both view images. To ameliorate such problems, we propose a robust method to obtain accurate disparity maps. The novel Absolute Adaptive Normalized Cross Correlation (AANCC) for anaglyph data cost is introduced in this paper. Then, it is followed by occlusion detection and segmentation-based plane fitting to achieve accurate depth map acquisition. Experimental results confirm that the proposed anaglyph data cost is robust and gives accurate disparity maps.

• 대한기계학회논문집
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• 제18권11호
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• pp.2944-2953
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• 1994

Active range finders using laser beam have been widely used for the factory automation and quality assurance, but they may be unreliable if the object' slope is steep or its surface is specular. The reliability of an active range finder was analyzed for the variation of the reflected laser beam intensity. First, the properties of the object's reflection were modeled by using the bidirectional reflectance-distribution function(BRDF), and then the variation of the laser beam brightness was formulated for the different configuratioin of the object and sensor. The experimental data of the laser beam reflection were obtained for two materials, mild steel and stainless steel. The parameters of the proposed model were obtained by fitting the data of the mild steel to the model and it was found that the results calculated from the proposed model were in good agreement with the experimental data.

• 한국생산제조학회지
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• 제8권6호
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• pp.78-83
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• 1999

This study discusses a non-contact optical technique, electronic speckle pattern interformetry(ESPI), that is well suited for in-plane and out-of-plane deformation measurement. However, the existing ESPI methods that are based on dual-exposure, real-time and time-average method have difficulties for accurate measurement of structure, due to irregular intensity and shake of phase. Therefore, phase shifting method has been proposed in order to solve this problem. About the method, the path of reference light in interferometry is shifted and added to least square fitting method to make the improvement in distinction and precision. This proposed method is applied to measure in -plane displacement that is compared with the previous method. Also, Used as specimen AS4/PE따 [30/=30/90]s was analyzed by ESPI based on real-time to determine the characteristics of vibration under no-load and tension. These results are quantitatively compared with those of FEM analysis inmode shapes.

• Journal of Mechanical Science and Technology
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• 제14권5호
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• pp.518-529
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• 2000

A detailed and thorough parametric study of digital image correlation method is presented. A theoretical background and development of the method were introduced and the effects of various parameters on the determination of displacement outputs from the raw original and deformed image information were examined. Use of the normalized correlation coefficient, the use of 20 to 40 pixels for a searching window side, 6 variables searching, bi-cubic spline sub pixel interpolations and the use of coarse-fine search are some of the key choices among the results of parametric studies. The displacement outputs can be further processed with two dimensional curve fitting for the data noise reduction as well as displacement gradient calculation.

• Bulletin of the Korean Chemical Society
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• 제7권1호
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• pp.59-62
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• 1986

Folded Box coherent anti-Stokes Raman spectroscopy (FBCARS) spectra of the fundamental symmetric stretch(213 $cm^{-1}$) and the first overtone(421 $cm^{-1}$) of $I_2$ have been recorded over the pump wavelength range from 495 nm to 580 nm. The lineshapes were fitted using the least squares method and the A and C term of CARS were calculated. From the fitting of A and C terms, the real(R) and imaginary(I) term intensity of CARS were calculated using harmonic oscillator program. The calculated CARS excitation profile of $I_2$ with R and I term data was about 270 $cm^{-1}$ red shifted from the absorption spectrum.

• Journal of Information Processing Systems
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• 제15권1호
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• pp.7-21
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• 2019

In order to improve the edge segmentation effect of the level set image segmentation and avoid the influence of the initial contour on the level set method, a saliency level set image segmentation model based on local Renyi entropy is proposed. Firstly, the saliency map of the original image is extracted by using saliency detection algorithm. And the outline of the saliency map can be used to initialize the level set. Secondly, the local energy and edge energy of the image are obtained by using local Renyi entropy and Canny operator respectively. At the same time, new adaptive weight coefficient and boundary indication function are constructed. Finally, the local binary fitting energy model (LBF) as an external energy term is introduced. In this paper, the contrast experiments are implemented in different image database. The robustness of the proposed model for segmentation of images with intensity inhomogeneity and complicated edges is verified.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권9호
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• pp.3782-3796
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• 2020

A three-dimensional (3D) reconstruction is an important research area in computer vision. The ability to detect and match features across multiple views of a scene is a critical initial step. The tracking matrix W obtained from a 3D reconstruction can be applied to structure from motion (SFM) algorithms for 3D modeling. We often fail to generate an acceptable number of features when processing face or medical images because such images typically contain large homogeneous regions with minimal variation in intensity. In this study, we seek to locate sufficient matching points not only in general images but also in face and medical images, where it is difficult to determine the feature points. The algorithm is implemented on an adaptive threshold value, a scale invariant feature transform (SIFT), affine SIFT, speeded up robust features (SURF), and affine SURF. By applying the algorithm to face and general images and studying the geometric errors, we can achieve quasi-dense matching points that satisfy well-functioning geometric constraints. We also demonstrate a 3D reconstruction with a respectable performance by applying a column space fitting algorithm, which is an SFM algorithm.

• 한국의류산업학회지
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• 제20권1호
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• pp.63-74
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• 2018

The purpose of this study is to investigate the differences in riding characteristics and helmet wearing conditions between bicycle and PMV riders so that the basis data necessary for the development of suitable helmets for each group is provided. For this purpose, riding characteristics and helmet wearing conditions of bicycle and PMV users were investigated using online survey method and then the survey results were interpreted by in-depth interview conducted for bicycle and PMV users. The online survey results showed that the PMV group showed shorter driving distance and more driving frequency than bicycle group. This short driving distance was due to the limitation of battery capacity of PMVs. Helmet wearing rate was significantly lower in PMV group than in bicycle group, which was associated with relatively low chances to drive long distance on the motorway. In the PMV group, the 'urban helmets' were mainly used, in which the appearance of helmet was priorized, but in the bicycle group, the 'road cycle helmets' were mainly used, in which the light weight or ventilation were priorized. Urban helmets caused stronger pain and more fitting problems than road cycle helmets because the head shapes of Koreans were not properly applied to the helmet design. Since the fitting problem and pain intensity were the important causes that making PMV users not wear the helmets, it is necessary to develop the urban helmets reflecting the head shapes of Koreans in order to increase the helmet wearing rate of the PMV users.

• 대한전자공학회논문지SP
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• 제46권6호
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• pp.1-15
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• 2009

본 논문에서는 이동 중인 철도차량 제륜자의 두께, 편마모 및 제륜자와 차륜 사이의 거리를 자동으로 측정하는 시스템을 제안한다. 철도차량의 제륜자는 촬영 시스템이 설치된 곳을 지날 때 자동으로 촬영되며, 두께 등을 측정하기 위해 가장 먼저 영상 내에서 제륜자의 위치를 검출한다. 이는 제륜자의 위치가 영상 마다 다르기 때문이며 이를 적응적으로 찾기 위해, 제륜자와 차륜 사이에 나타나는 그림자 영역을 이용한다. 그림자 영역의 경계는 9차 다항식을 통해 모델링되며, 그 영역을 지나는 임의의 곡선 (초기 곡선)은 제약 곡선 피팅 방법을 통해 검출된다. 다음은 검출된 초기 곡선과 명암도 변화 정보를 이용하여 제륜자의 앞과 뒤, 차륜 상의 세 곡선 및 제륜자의 수직면을 지나는 직선을 검출한다. 최종적으로, 앞서 구한 곡선과 직선을 이용하여 제륜자의 두께, 편마모 및 제륜자와 차륜 사이의 거리를 측정한다. 실험에서는 제안된 방법을 실제 선로에서 촬영한 영상에 대해 적용해 보았으며, 그 결과 평균 0.654mm의 두께 측정 오차를 나타내었다.

• Archives of Plastic Surgery
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• 제47권1호
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• pp.62-69
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• 2020

Background Cryolipolysis, a preferred method for minimally invasive body contouring, involves the noninvasive cooling of adipocytes to induce lipolysis without damaging other tissues. This study aimed to evaluate the safety and efficacy of cryolipolysis for the treatment of excessive fat tissue. Methods Between May 2014 and December 2017, 231 patients with 448 areas of interest were enrolled and their records were retrospectively reviewed. We used five different vacuum applicators, and the best-fitting applicator was used for each area. One cycle of cryolipolysis was applied at a cooling intensity factor of 41.6. The efficacy was evaluated 12 weeks after treatment via review of clinical photographs, the pinch test, and ultrasonographic measurements of fat thickness. The occurrence of any complications was also assessed. Results The volume was reduced in all of the areas to which cryolipolysis was applied. The rate of reduction of the fat layer as measured via the pinch test was 19.2%, and the rate of the decrease in fat layer thickness as measured via ultrasonography was 22.8%. Fat reduction of the upper arm differed significantly from that of the abdomen and flank, but no significant difference was found between sexes. The side effects were limited to erythema, edema, bruising, and numbness at the treatment site and resolved without treatment. Conclusions Cryolipolysis, with new and better-fitting applicators, is safe, fast, and effective for the reduction of excessive fat tissue on the abdomen, back, flank, and extremities. It is a good option for treating excess adipose tissue in Asian patients.