• Spatial Information Research
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• 제19권1호
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• pp.29-40
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• 2011

정지궤도 해색 센서(GOCI: Geostationary Ocean Color Imager) 는 세계 최초의 정지궤도 위성으로 매일 1 시간마다 8 장의 영상을 획득 할 수 있어 육상파 해양 모두 활용성이 높은 위성이다. 그러나 500m의 GSD(Ground Sample Distance)를 지니는 서해성도 영상은 육성 활용에 한계가 있다. 최근, 컴퓨터 비전분야에서 활발히 진행 중인 기술인 Super Resolution(이하 SR)는 유사 시간대에 촬영한 저해상도 영상으로부터 고해상도 영상을 제작하는 기술로, 이를 시간 해상도가 높은 시계열 위성인 GOCI에 적용한다면 해상도가 향상 된 영상을 제작하는 기술로, 이를 시간 해상도가 높은 시계열 위성인 GOCI에 적용한다면 해상도가 향상 된 영상의 취득이 가능하며, 또한 광학 위성 영상의 단점인 구름에 의해 손실된 지상 정보의 복원이 가능할 것이다. 본 연구에서는, GOCI 자료를 위한 효율적인 초해상도 영상 복원 알고리즘 개발을 위한 선행연구로써 위성 영상 취득과정과 유사한 환경의 시뮬레이션을 통해 시계열 자료를 제작하고, 제작된 자료를 제안한 알고리즘에 적용함으로서 0.1 단위의 픽셀 정합도를 확인하였고, 원본 영상과 RMSE 0.5763, PSNR 52.9183 db, SSIM Index 0.9486의 정확도를 나타낸 HR 영상을 복원하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.51-51
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• 2000

The ambiguity resolution is an essential task for the precise carrier phase differential GPS. In practice, however, there are still many problems in resolving the ambiguity in kinematic mode, especially in the urban areas. The multipath in received signal, the frequent change in visible satellites, and the cyclic slips make the ambiguity resolution very difficult task in real-time operation. In this paper, we consider a differential positioning with the float ambiguity that is free from the integer constraint. The float ambiguity estimation if carried out by the Kalman filter. The float and fixed ambiguities are combined together to determine the position in real-time kinematic mode.

• 정보저장시스템학회논문집
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• 제1권2호
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• pp.132-136
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• 2005

It is widely accepted that the reading mechanism of Super-RENS(super-resolution near field structure) and Super-ROM(super-resolution read only memory) is closely related with non-linear temperature dependent material properties such as refractive indices, phase change. Furthermore, the dynamic change of the temperature distribution also an essential part of reading mechanism of Super-RENS/ROM. Therefore, the knowledge of the temperature distribution as a function a time is one of the important keys to reveal the physics of reading mechanism in Super-RENS/ROM. We calculated time-dependent temperature distribution in a 3-dimensional Super-ROM disk structure when moving laser beam is irradiated. With a help of commercial software FEMLAB which employed finite element method, we simulated the temperature distribution of ROM structure whose pit diameter is 120-nm with 50-nm depth. Energy absorption by moving laser irradiation, time variations of heat transfer processes, heat fluxes, heat transfer ratios, and temperature distributions of the complicate 3-dimensional ROM structure have been obtained.

• 대한전자공학회논문지SP
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• 제41권5호
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• pp.225-233
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• 2004

본 논문에서는 기존에 PC 모니터와 프린터 사이의 색 재현성 향상을 위해서 사용되던 색역폭 매핑 방법을 디스플레이 장치에 적용하기 위한 실시간 색역폭 매핑 방법을 제시하였다. 다양한 디스플레이 장치가 개발됨에 따라서 각 디스플레이 별로 색 재현성의 차이가 발생하고 있으며 기존의 색역폭 매핑 방법을 디지털 TV의 디스플레이 장치에 적용하기 위해서는 수 나노초 단위의 처리 속도가 필요하다. 이를 위하여 본 논문에서는 절감 3차원 룩업 테이블(three-dimensional reduced resolution look-up table)의 하드웨어 구조를 제안하고 이를 이용하여 색역폭 매핑을 실시간으로 수행하는 방법을 제공한다. 제안된 하드웨어 구조는 먼저 simulation을 통하여 타당성을 검증하였으며 이후 FPGA와 ASIC으로 구현되어 디지털 TV의 디스플레이 장치의 화질 개선에 성공적으로 적용되었다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.317-320
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• 2003

In this paper, we present real-time, accurate face region detection and tracking technique for an intelligent surveillance system. It is very important to obtain the high-resolution images, which enables accurate identification of an object-of-interest. Conventional surveillance or security systems, however, usually provide poor image quality because they use one or more fixed cameras and keep recording scenes without any clue. We implemented a real-time surveillance system that tracks a moving person using pan-tilt-zoom (PTZ) cameras. While tracking, the region-of-interest (ROI) can be obtained by using a low-pass filter and background subtraction. Color information in the ROI is updated to extract features for optimal tracking and zooming. The experiment with real human faces showed highly acceptable results in the sense of both accuracy and computational efficiency.

• 제어로봇시스템학회논문지
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• 제22권8호
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• pp.643-649
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• 2016

This paper presents a new image cache algorithm for real-time implementation of high-resolution color image warping. The cache memory is divided into four cache memory modules for simultaneous readout of four input image pixels in consideration of the color filter array (CFA) pattern of an image sensor and CFA image warping. In addition, a pipeline structure from the cache memory to an interpolator is shown to guarantee the generation of an output image pixel at each system clock cycle. The proposed image cache algorithm is applied to an FPGA-based real-time color image warping, and experimental results are presented to show the validity of the proposed method.

• 한국CDE학회논문집
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• 제11권4호
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• pp.315-325
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• 2006

It is very often necessary to search for similar parts during designing a new product because its parts are often easily designed by modifying existing similar parts. In this way, the design time and cost can be reduced. Thus it would be nice to have an efficient similarity comparison algorithm that can be used anytime in the design process. There have been many approaches to compare shape similarity between two solids. In this paper, two parts represented in B-Rep is compared in two steps: one for overall appearances and the other for detail features. In the first step, geometric information is used in low level of detail for easy and fast pre-classification by the overall appearance. In the second step, feature information is used to compare the detail shape in high level of detail to find more similar design. To realize the idea above, a multi resolution algorithm is proposed so that a given solid is described by an overall appearance in a low resolution and by detail features in high resolution. Using this multi-resolution representation, parts can be compared based on the overall appearance first so that the number of parts to be compared in high resolution is reduced, and then detail features are investigated to retrieve the most similar part. In this way, computational time can be reduced by the fast classification in the first step while reliability can be preserved by detail comparison in the second step.

• 한국환경과학회지
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• 제13권10호
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• pp.891-902
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• 2004

In order to predict air pollution and Yellow-sand dispersion precisely, it is necessary to clarify the sensitivity of meteorological field input interval. Therefore numerical experiment by atmospheric dynamic model(RAMS) and atmospheric dispersion model(PDAS) was performed for evaluating the effect of temporal and spatial resolution of meteorological data on particle dispersion. The results are as follows: 1) Base on the result of RAMS simulation, surface wind direction and speed can either synchronize upper wind or not. If surface wind and upper wind do not synchronize, precise prediction of Yellow-sand dispersion is strongly associated with upwelling process of sand of particle. 2) There is no significant discrepance in distribution of particle under usage of difference temporal resolution of meteorological information at early time of simulation, but the difference of distribution of particles become large as time goes by. 3) There is little difference between calculated particles distributions in dispersion experiments with high temporal resolution of meteorological data. On the other hand, low resolution of meteorological data occur the quantitative difference of particle density and there is strong tendency to the quantitative difference.

• 한국측량학회지
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• 제31권6_2호
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• pp.559-565
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• 2013

Spatial resolution of land covers from remotely sensed images can be increased using super-resolution mapping techniques for soft-classified land cover proportions. A further development of super-resolution mapping technique is downscaling the original remotely sensed image using super-resolution mapping techniques with a forward model. In this paper, the model for increasing spatial resolution of remote sensing multispectral image is tested with real SPOT 5 imagery at 10m spatial resolution for an area in Bac Giang Province, Vietnam in order to evaluate the feasibility of application of this model to the real imagery. The soft-classified land cover proportions obtained using a fuzzy c-means classification are then used as input data for a Hopfield neural network (HNN) to predict the multispectral images at sub-pixel spatial resolution. The 10m SPOT multispectral image was improved to 5m, 3,3m and 2.5m and compared with SPOT Panchromatic image at 2.5m resolution for assessment.Visually, the resulted image is compared with a SPOT 5 panchromatic image acquired at the same time with the multispectral data. The predicted image is apparently sharper than the original coarse spatial resolution image.

• 대한의용생체공학회:의공학회지
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• 제22권3호
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• pp.223-229
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• 2001

In this paper, we have compared the direct fan-beam reconstruction method with the rebinning method in terms of computation time and spatial resolution using computer simulation. As a result, the direct fan-beam method is superior to the rebinning method in the spatial resolution though the former needs longer computation time. However, if we adopt the quarter-detector-offset technique to improve the spatial resolution, the rebinning method outperforms the direct fan-beam method. The computation times have been evaluated using the fast algorithms optimized to reduce the number of interpolation calculations at the back-projection, and the spatial resolutions have been compared using the computer generated phantoms.