• 한국컴퓨터정보학회논문지
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• 제21권5호
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• pp.31-40
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• 2016

In this paper, we analyse the characteristics of the edge image and propose a new entropy coding optimized to the compression of the edge image. The pixel values of the edge image have the Gaussian distribution around '0', and most of the pixel values are '0'. By using this analysis, the Zero Block technique is utilized in spatial domain. And the Intra Prediction Mode of the edge image is similar to the mode of the surrounding blocks or likely to be the Planar Mode or the Horizontal Mode. In this paper, we make use of the MPM technique that produces the Intra Prediction Mode with high probability modes. By utilizing the above properties, we design a new entropy coding method that is suitable for edge image and perform the compression. In case the existing compression techniques are applied to edge image, compression ratio is low and the algorithm is complicated as more than necessity and the running time is very long, because those techniques are based on the natural images. However, the compression ratio and the running time of the proposed technique is high and very short, respectively, because the proposed algorithm is optimized to the compression of the edge image. Experimental results indicate that the proposed algorithm provides better visual and PSNR performance up to 11 times than the JPEG.

• Asian Pacific Journal of Cancer Prevention
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• 제14권3호
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• pp.1715-1720
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• 2013

Background: The discovery that microRNAs (miRNAs) regulate proliferation, invasion and metastasis provides a principal molecular basis of tumor heterogeneity. Microvessel distribution is an important characteristic of solid tumors, with significant hypoxia occurring in the center of tumors with low blood flow. The distribution of miR-374a in breast tumors was examined as a factor likely to be important in breast cancer progression. Methods: Breast tissue samples from 40 patients with breast cancer were classified into two groups: a highly invasive and metastatic group (HIMG) and a low-invasive and metastatic Group (LIMG). Samples were collected from the center and edge of each tumor. In each group, six specimens were examined by microRNA array, and the remaining 14 specimens were used for real-time RT-qPCR, Western blot and immunohistochemical analyses. Correlation analysis was performed for the miRNAs and target proteins. Follow-up was carried out during 28 months to 68 months after surgery, and survival data were analyzed. Results: In the LIMG, the relative content of miR-374a was lower in the center of the tumor than at its edge; in the HIMG, it was lower at the edge of the tumor, and miR-374a levels were lower in breast cancer tissues than in normal tissues. There was no difference between VEGF-A and VCAM-1 mRNA levels at the edge and center of the tumor; however, we observed a significant difference between VEGF-A and VCAM-1 protein expression levels in these two regions. There was a negative correlation between miR-374a and target protein levels. The microvessel density (MVD) was lower in the center of the tumor than at its edge in HIMG, but the LIMG vessels were uniformly distributed. There was a significant positive correlation between MVD and the number of lymph node metastases (Pearson correlation, r=0.912, P<0.01). The median follow-up time was 48.5 months. LIMG had higher rate of disease-free survival (100%, P=0.013) and longer median survival time (66 months) than HIMG, which had a lower rate of 75% and shorter median survival time (54 months). Conclusions: Our data demonstrated miR-374a to be differentially distributed in breast cancer; VEGF-A and VCAM-1 mRNA had coincident distribution, and the distribution of teh respective proteins was uneven and opposite to that for the miR-374a. These data might explain the differences in the distribution of MVD in breast cancer and variation in breast cancer prognosis.

• 한국광학회:학술대회논문집
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• 한국광학회 2004년도 하계학술발표회
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• pp.84-85
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• 2004

• 한국지능시스템학회논문지
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• 제7권4호
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• pp.18-28
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• 1997

이 논문에서는 영상데이터를 여러개의 영상블록들로 나누고 이산 코사인변환 영역에서 물체의 에지에 해당하는 영상블록을 에지방향을 고려하여 적절히 분류함으로써 영상데이터를 효과적을 압축하였다. 벡터양자화에 의한 영상데이터의 압축은 높은 압축률을 실현할 수 있지만 영상내 물체의 에지부근이 손상되어 시각적인 화질이 저하되는 단점이 있다. 높은 압축률을 유지하면서도 시각적인 화질의 열화를 피하기 위하여 영상블록의 이산 코사인변환계수의 에너지 분포에 따라 에지블록을 8개의 부류로 분류하였다. 또한 이 분류과정을 통하여 얻어진 데이터를 가지고 신경회로망을 학습하여 구현한 에지블록의 분류과정과 성능을 비교하였다. 에너지분포에 의한 에지분류방법과 신경망으로 학습한 분류과정은 에지특성벡터에 의한 분류벡터양자화에 비해 더 높은 PSNR과 시각적으로 좋은 화질을 보여주었다.

• 한국통신학회논문지
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• 제34권4A호
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• pp.316-323
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• 2009

본 논문은 셀간 간섭을 제어하여 셀 경계 사용자의 데이터 전송율을 증가시키는 기술인 소프트 주파수 재사용시 전력 할당에 관한 것이다. 소프트 주파수 재사용 기술은 셀 경계 사용자의 데이터 전송율을 개선하는데 유용한 기술이나 주파수 재사용 지수가 증가되어 셀 평균 데이터 전송율을 감소시키는 문제가 있다. 본 논문에서는 하나의 중앙 제어기가 물리적 거리가 인접한 여러 개의 셀을 제어하는 환경에서, 셀 경계 사용자의 데이터 전송율 개선하면서도 셀 평균 전송율 감소를 최소화하도록 소프트 주파수 재사용을 위한 송신 전력 할당 기법을 제안한다. 시스템 시뮬레이션을 통하여 인접한 두 셀에 소프트 주파수 재사용 기술을 적용하여 소프트 주파수 재사용에 의한 셀 평균 데이터 전송율 감소 정도와 제안하는 전력 할당 기법에 의한 셀 평균 데이터 전송을 개선을 살펴본다.

• Journal of KIEE
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• 제11권1호
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• pp.69-77
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• 2001

This paper describes an image processing algorithm capable of recognizing road lanes by using a CDF(cumulative distribution function). The CDF is designed for the model function of road lanes. Based on the assumptions that there are no abrupt changes in the direction and location of road lanes and that the intensity of lane boundaries differs from that of the background, we formulated the CDF, which accumulates the edge magnitude for edge directions. The CDF has distinctive peak points at the vicinity of lane directions due to the directional and the positional continuities of a lane. To obtain lane-related information a scatter diagram was constructed by collecting edge pixels, of which the direction corresponds to the peak point of the CDF, then the principal axis-based line fitting was performed for the scatter diagram. Noises can cause many similar features to appear and to disappear in an image. Therefore, to reduce the noise effect a recursive estimator of the CDF was introduced, and also to prevent false alarms or miss detection a scene understanding index (DUI) was formulated by the statistical parameters of the CDF. The proposed algorithm has been implemented in real time on video data obtained from a test vehicle driven on a typical highway.

• 한국정보통신학회논문지
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• 제10권3호
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• pp.549-555
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• 2006

에지검출은 영상처리와 컴퓨터비젼의 매우 중요한 연구분야이다. 그리고 일반적인 에지검출 연산자인 Robert, Sobel, Kirsh등의 연산자는 계단에지를 검출하는데는 적합하나 잡음에 매우 민감한 단점을 가지고 있다. 따라서 본 논문에서는 영상정보척도와 신경회로망을 이용한 잡음에 매우 강한 계단에지 검출방법을 제안한다. 계단에지의 명암도 분포의 차, 방향성, 연속성, 구조성 등의 계단에지의 기본적인 정보특성을 이용한 함수를 BP 신경회로망의 입력벡터로 구성한 결과 매우 위치가 정확한 계단에지를 얻을 수 있었다. 또한 실험 영상으로 장미 영상과 세포영상을 사용하여 매우 만족스런 실험 결과를 얻을 수 있었다.

• 대한원격탐사학회지
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• 제36권4호
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• pp.503-513
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• 2020

This paper presents a method to evaluate denoising filters based on edge locations in their denoised images. Image quality assessment has often been performed by using structural similarity (SSIM). However, SSIM does not provide clearly the geometric accuracy of features in denoised images. Thus, in this paper, a method to localize edge locations with subpixel accuracy based on adaptive weighting of gradients is used for obtaining the subpixel locations of edges in ground truth image, noisy images, and denoised images. Then, this paper proposes a method to evaluate the geometric accuracy of edge locations based on root mean squares error (RMSE) and jaggedness with reference to ground truth locations. Jaggedness is a measure proposed in this study to measure the stability of the distribution of edge locations. Tested denoising filters are anisotropic diffusion (AF), bilateral filter, guided filter, weighted guided filter, weighted mean of patches filter, and smoothing filter (SF). SF is a simple filter that smooths images by applying a Gaussian blurring to a noisy image. Experiments were performed with a set of simulated images and natural images. The experimental results show that AF and SF recovered edge locations more accurately than the other tested filters in terms of SSIM, RMSE, and jaggedness and that SF produced better results than AF in terms of jaggedness.

• 한국정보과학회논문지:소프트웨어및응용
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• 제34권11호
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• pp.961-970
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• 2007

국소적 미분 연산자를 이용한 대개의 에지 검출 방법을 사용하면 검출된 에지의 폭이 불균일하게 되거나, 확대된 영상에서 에지의 일부를 검출하지 못한다. 캠프 에지의 엄격하게 단조적인 자기 분포구간을 단순 계단 함수에 대응시키는 램프 에지의 완전 선명화 사상을 이용하면 자기분포의 비국소적 속성이 반영되는 변형된 미분이 도입되고, 이를 이용하면 다양한 에지 폭의 변화에 효율적으로 대응할 수 있는 에지 검출기를 구현할 수 있다. 본 논문에서는 MADD를 사용하여 형상의 확대나 다양한 에지 폭의 변화에 안정적으로 동작하는 검출기를 개발하였다. 기존의 알고리즘과 비교하여 본 결과 제안한 알고리즘의 우수성을 확인할 수 있었다.

• 전기의세계
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• 제23권4호
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• pp.39-45
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• 1974

In most previous research work, the transverse edge effect has been allowed for only by use of a relativity-increase factor. This paper gives a more exact treatment. A two-dimensional-field analysis is presented for the problem of sheet rotor linear induction motor with finite width the method used takes account of flux leakage in the space between the stator and secondary sheet rotor as well as in the secondary itself. Equations are derived for the flux density distribution in the air gap and for the starting face, in each case as a function of stator current. The cross gap flux density peaks towards athe edge of the stator. This phenomena is known as the transverse edge effect. Measurements of the flux density in the air gap and starting force on a linear induction motor with sheet rotor of different width showed a reasonable agreement,suggest that it would be desirable to take into account also, at least for this motor in which severe redistribution occurs.