• 농업과학연구
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• 제47권4호
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• pp.1109-1122
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• 2020

The aim of this study was to develop a marbling classification and prediction model using small parts of sirloin images based on a deep learning algorithm, namely, a convolutional neural network (CNN). Samples were purchased from a commercial slaughterhouse in Korea, images for each grade were acquired, and the total images (n = 500) were assigned according to their grade number: 1++, 1+, 1, and both 2 & 3. The image acquisition system consists of a DSLR camera with a polarization filter to remove diffusive reflectance and two light sources (55 W). To correct the distorted original images, a radial correction algorithm was implemented. Color images of sirloins of Hanwoo (mixed with feeder cattle, steer, and calf) were divided and sub-images with image sizes of 161 × 161 were made to train the marbling prediction model. In this study, the convolutional neural network (CNN) has four convolution layers and yields prediction results in accordance with marbling grades (1++, 1+, 1, and 2&3). Every single layer uses a rectified linear unit (ReLU) function as an activation function and max-pooling is used for extracting the edge between fat and muscle and reducing the variance of the data. Prediction accuracy was measured using an accuracy and kappa coefficient from a confusion matrix. We summed the prediction of sub-images and determined the total average prediction accuracy. Training accuracy was 100% and the test accuracy was 86%, indicating comparably good performance using the CNN. This study provides classification potential for predicting the marbling grade using color images and a convolutional neural network algorithm.

• 대한조선학회논문집
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• 제61권3호
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• pp.143-151
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• 2024

In this study, we present a mapping framework for 3D spatial reconstruction of digital twin model using navigation and perception sensors mounted on an Autonomous Surface Vehicle (ASV). For improving the level of realism of digital twin models, 3D spatial information should be reconstructed as a digitalized spatial model and integrated with the components and system models of the ASV. In particular, for the 3D spatial reconstruction, color and 3D point cloud data which acquired from a camera and a LiDAR sensors corresponding to the navigation information at the specific time are required to map without minimizing the noise. To ensure clear and accurate reconstruction of the acquired data in the proposed mapping framework, a image preprocessing was designed to enhance the brightness of low-light images, and a preprocessing for 3D point cloud data was included to filter out unnecessary data. Subsequently, a point matching process between consecutive 3D point cloud data was conducted using the Generalized Iterative Closest Point (G-ICP) approach, and the color information was mapped with the matched 3D point cloud data. The feasibility of the proposed mapping framework was validated through a field data set acquired from field experiments in a inland water environment, and its results were described.

• 한국전산유체공학회지
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• 제15권2호
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• pp.28-34
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• 2010

Conductive and radiative thermal model configurations of an imager of a geostationary satellite are presented. A two-plane method is introduced for three dimensional conductive coupling which is not able to be treated by thin shell plate thermal modeling technique. Especially the two-plane method is applied to massive matters and PIP(Payload Interface Plate) in the imager model. Some massive matters in the thermal model are modified by adequate correction factors or equivalent thickness in order to obtain the numerical results of thermal modeling to be consistent with the analytic model. More detailed nodal breakdown is specially employed to the object which has the rapid temperature gradient expected by a rule of thumb. This detailed thermal model of the imager is supposed to be used for analyses and test predictions, and be correlated with the thermal vacuum test results before final in-flight predictions.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제12권3호
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• pp.42-48
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• 1990

This is a case report on an unusual - heavy buccal frenum in young lady which was treated by frenectomy, vestibuloplasty and total-palatal mucosal free graft. The authors noticed that this abnormal condition lead several chronic complications in young patient as like as premature loss of upper molar teeth, early and rapid loss of alveolar bone around insertion of frenum, over - extended eruption of lower molar teeth and abnormal mandibular movements, etc. After frenectomy and surgical extension of buccal vestiblue on both upper and lower posterior regions, we obtained a full - sized palatal mucosal graft and moved it on upper and lower extension area seperately as two pieces of free grafts to offer inherent function of denture - bearing mucogingiva and same color - matching with oral mucosa and to prevent post - operative relapse of vestibular height. We discussed here about unusual abnormality and their complications of unusual buccal frenum and its treatment.

• 한국산업정보학회논문지
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• 제22권3호
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• pp.27-38
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• 2017

본 연구는 다수의 개인 사용자들이 휴대폰 카메라를 통하여 공연장 등에서 녹화한 다수의 영상을 스티칭하는 방법을 제시한다. 기존 고정형 리그(Rig)를 사용하는 360 카메라 솔루션과 대비하여, 시간 동기화, 반복적 변환행렬계산 및 카메라 센서 불일치 보정과 같은 새로운 문제들을 해결해야한다. 이 논문에서는 오디오를 사용한 시각동기화 방법, 색상 전달 방식에 따른 센서 불일치 제거, 전역 동작 안정화 알고리즘을 사용하여 변환 행렬의 업데이트를 함으로써 이러한 문제를 해결하였다. 또한, 카메라의 움직임이 크지 않은 경우에서, 제안 된 알고리즘은 화면 별 스티칭을 하는 경우 보다, 계산 속도와 화질 면에서도 우수한 성능을 보임을 실험을 통하여 확인하였다.

• 중소기업융합학회논문지
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• 제6권4호
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• pp.99-106
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• 2016

본 논문에서는 White 색상을 달성하기 위한 R, G, B 혼합비율 Type을 기반으로 상대적으로 열화된 BER성능을 달성하는 파장 대역에 Forward Error Correction (FEC) 기법을 적용하여, 전체 시스템의 BER성능을 향상 시킬 수 있는 가시광 통신 시스템을 제안한다. FEC기법으로 Low Density Parity Check (LDPC) 코드를 적용하였으며, LDPC 부호는 Shannon의 한계치에 가장 근접하는 오류정정 부호로 평가되고 있으며, 오류마루(error floor) 현상이 나타나지 않고, 완전 병렬처리가 가능하여 고속 복호가 가능한 장점을 가지고 있다. 이와 같은 시스템에서 LDPC채널 코딩을 각 파장 대역에 부분적으로 적용함으로써, 주파수 효율 감소 및 데이터 전송률 감소를 완화 할 수 있다.

• 대한원격탐사학회지
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• 제28권3호
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• pp.277-285
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• 2012

The GOCI imagery can be an effective alternative to monitor short-term changes over terrestrial environments. This study aimed to assess the radiometric characteristics of the GOCI multispectral imagery for land applications. As an initial approach, we compared GOCI at-sensor radiance with MODIS data obtained simultaneously. Dynamic range of GOCI radiance was larger than MODIS over land area. Further, the at-sensor radiance over various land surface targets were tested by vicarious calibration. Surface reflectance were directly measured in field using a portable spectrometer and indirectly derived from the atmospherically corrected MODIS product over relatively homogeneous sites of desert, tidal flat, bare soil, and fallow crop fields. The GOCI radiance values were then simulated by radiative transfer model (6S). In overall, simulated radiance were very similar to the actual radiance extracted from GOCI data. Normalized difference vegetation index (NDVI) calculated from the GOCI bands 5 and 8 shows very close relationship with MODIS NDVI. In this study, the GOCI imagery has shown appropriate radiometric quality to be used for various land applications. Further works are needed to derive surface reflectance over land area after atmospheric correction.

• 한국멀티미디어학회논문지
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• 제17권2호
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• pp.257-265
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• 2014

3D입체영상은 인간의 눈을 지향하면서 하드웨어의 발전에 따라 새롭게 부각되고 있다. 그러나 3D입체영상은 두 대의 카메라 또는 두 개의 렌즈를 사용하면서 2D영상의 제작에 비해 많은 시간과 노력을 필요로 한다. 본 연구에서는 3D입체영상의 제작기법을 활용하여 라이더영상을 제작하기 위한 시스템의 장단점을 분석하고, 효과적인 입체감의 형성을 위한 요소를 적용하여 연출의도에 부합하는 3D입체 라이더영상을 제작할 수 있는 방안을 모색하였다. 연구결과 3D입체 라이더영상은 장르적 특성으로 인해 경량화된 일체형 시스템이 효과적이었으며, 후반작업에서의 Time Remapping, 색보정, 그래픽요소의 추가를 고려한 로케이션 촬영이 요구되었다.

• 대한원격탐사학회지
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• 제30권1호
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• pp.1-12
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• 2014

본 연구의 목적은 최신 상용 소프트웨어에서 지원하고 있는 영상 모자이크 기법을 비교 분석하고, 제작된 모자이크 영상들의 정량적인 품질평가 방법을 제시하는 것이다. 상대적으로 뛰어난 성능을 나타내는 것으로 알려져 있는 모자이크 기법을 계절적 특성이 서로 다른 7장의 KOMPSAT-2 위성영상에 적용하였고, 각각의 결과를 시각적으로 비교 분석하였다. 또한, 제작된 모자이크 영상의 성능을 비교 할 수 있는 정량적 평가지수를 제안하고, 시각적 결과와 비교 검증을 수행함으로써 제안된 품질평가 지수의 적용 가능성을 제시하였다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 춘계학술대회 논문집
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• pp.95-100
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• 2006

Measurements of ocean color from space since 1970s provided vital information with reference to physical and biogeochemical properties of the oceanic waters. The utility of these data has been explored in order to map and monitor highly toxic/or harmful algal blooms (HABs) that affected most of coastal waters throughout the world due to accelerated eutrophication from human activities and certain oceanic processes. However, the global atmospheric correction and bio-optical algorithms developed for oceanic waters were found to yield false information about the HABs in coastal waters. The present study aimed to evaluate the potential use of red tide index (RI) method, which has been developed by Ahn and Shanmugam (2005), for mapping of HABs in Korean and neighboring waters. Here we employed the SSMM to remove the atmospheric effect in the SeaWiFS image data and the achieved indices by RI method were found more appropriate in correctly identifying potential areas of the encountered HABs in Korean South Sea (KSS) and Chinese coastal waters during 1999-2004. But the existence of high absorbing and scattering materials greatly interfered with the standard OC4 algorithm which falsely identified red tides in these waters. In comparison with other methods, the RI approach for the early detection of HABs can provide state managers with accurate identification of the extent and location of these blooms as a management tool.