• Title/Summary/Keyword: LoG

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On the growth and properties of GaP single crystals (GaP단결정의 성장과 특성에 관하여)

  • 김선태;문동찬
    • Electrical & Electronic Materials
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    • v.5 no.3
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    • pp.284-294
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    • 1992
  • 합성용질확산법으로 GaP단결정을 성장시키고 몇가지 성질을 조사하였다. 정지상태에서 결정의 성장속도는 1.75[mm/day]이었고 결정성장용 석영관을 전기로내에서 하강시키므로써 양질의 GaP 단결정을 성장하였다. 에치피트밀도는 결정의 성장축 방향으로 3.8*$10^{4}$[$cm^{-2}$]부터 2.3*$10^{5}$[$cm^{-2}$] 까지 증가하였다. 성장된 GaP결정의 이동도와 캐리어농도는 실온에서 197.49[$cm^{2}$/V.sec]와 6.75*$10^{15}$[$cm^{-3}$]이었고 77K의 온도에서는 266.91[$cm^{2}$ /V.sec]와 3.13*$10^{14}$[$cm^{-3}$]이었다. 에너지갭의 온도의존성은 실험적으로 $E_{g}$(T)=2.3383-(6.082*$10^{-4}$) $T^{2}$/(373.096+T)[eV]로 구하여졌다. 저온에서 측정된 광루미네센스 스펙트럼은 구속된 여기자의 복사재결합과 재결합 과정에 포논의 참여로 인하여 에너지갭 부근의 복잡한 선 스펙트럼이 나타났고 얕은 준위의 Si도너와 Zn억셉터준위 사이에서의 복사재결합 및 이에 대한 1LO, 2LO의 포논복제가 나타났으며 S $i_{Ga}$ -S $i_{p}$의 쌍방출에 의하여 1.8932[eV]에서 넓은 반치전폭의 피크가 나타났다. GaP의 적외선 흡수는 TO, LO, LA, T $A_{1}$, T $A_{2}$ 포논들의 이중결합모드와 G $a_{2}$O의 진동모드 및 Si도너와 Zn억셉터들에 의하여 일어났다. Zn를 확산시키어 제작한 p-n GaP발광다이오드는 실온에서의 발광중심피크가 6250[.angs.]이었고 최대광출력은 0.0916[mW], 양자효율은 0.51%이었다.이었다.

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Total replacement of dietary fish oil with alternative lipid sources in a practical diet for mandarin fish, Siniperca scherzeri, juveniles

  • Sankian, Zohreh;Khosravi, Sanaz;Kim, Yi-Oh;Lee, Sang-Min
    • Fisheries and Aquatic Sciences
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    • v.22 no.4
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    • pp.8.1-8.9
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    • 2019
  • A 12-week feeding trial was designed to evaluate the effect of total replacement of fish oil (FO) with terrestrial alternative oils on growth, feed utilization, body composition, hematological parameters, and fillet fatty acid profile of mandarin fish juveniles. Four iso-nitrogenous (56% crude protein) and iso-lipidic (13% crude lipid) practical diets were formulated. A control diet contained 6% FO and three other experimental diets were prepared by replacing FO with linseed oil, soybean oil, and lard (designed as FO, LO, SO, and lard, respectively). Each diet was randomly allocated to triplicate groups of 25 fish ($1.8{\pm}0.03g/fish$) in a circular tank. Complete replacement of FO by three tested alternative oils had no remarkable impact on growth performance, feed utilization efficiency, and morphological and hematological parameters of juvenile mandarin fish. However, daily feed intake was found to be significantly higher for fish fed the SO diet compared with those fed the FO and LO diets. Fish fed LO and SO diets exhibited significantly higher levels of the whole body lipid compared to fish fed diet containing FO. Fillet fatty acid composition reflected dietary fatty acid profile. The highest level of ${\alpha}$-linolenic acid, linoleic acid, and oleic acid was observed in fish fillet fed LO, SO, and lard, respectively. Although the eicosapentaenoic acid level of fish fillet fed diet FO was higher than other treatments, no significant difference was found in docosahexaenoic acid content among all dietary groups. The results of the present study clearly demonstrate that the complete replacement of FO in mandarin fish diets is achievable. These findings are useful in dietary formulation to reduce feed costs without compromising mandarin fish growth.

Novel Method for Face Recognition using Laplacian of Gaussian Mask with Local Contour Pattern

  • Jeon, Tae-jun;Jang, Kyeong-uk;Lee, Seung-ho
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.10 no.11
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    • pp.5605-5623
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    • 2016
  • We propose a face recognition method that utilizes the LCP face descriptor. The proposed method applies a LoG mask to extract a face contour response, and employs the LCP algorithm to produce a binary pattern representation that ensures high recognition performance even under the changes in illumination, noise, and aging. The proposed LCP algorithm produces excellent noise reduction and efficiency in removing unnecessary information from the face by extracting a face contour response using the LoG mask, whose behavior is similar to the human eye. Majority of reported algorithms search for face contour response information. On the other hand, our proposed LCP algorithm produces results expressing major facial information by applying the threshold to the search area with only 8 bits. However, the LCP algorithm produces results that express major facial information with only 8-bits by applying a threshold value to the search area. Therefore, compared to previous approaches, the LCP algorithm maintains a consistent accuracy under varying circumstances, and produces a high face recognition rate with a relatively small feature vector. The test results indicate that the LCP algorithm produces a higher facial recognition rate than the rate of human visual's recognition capability, and outperforms the existing methods.

Edge Detection Method using Modified Coefficient Masks (변형된 계수 마스크를 이용한 에지 검출 방법)

  • Lee, Chang-Young;Chung, Suk-Moon;Kim, Nam-Ho
    • Journal of the Institute of Electronics and Information Engineers
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    • v.50 no.5
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    • pp.218-223
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    • 2013
  • The performances of previous edge detection methods such as Sobel, Prewitt, and LoG(Laplacian of Gaussian) are insufficient for images degraded in AWGN(additive white Gaussian noise). Therefore, in this paper, we proposed an edge detection algorithm using a modified coefficient masks with gradient masks and distance weight mask. In order to confirm and verify the performance of the proposed algorithm, we simulated and compared proposed algorithm to conventional methods on various standard images added AWGN with a standard deviation ${\sigma}$=15, 30 and proposed algorithm shows superior edge detection characteristics in processed images.

A Study on Edge Detection Algorithm using Modified Mask of Weighting (변형된 가중치 마스크를 이용한 에지검출 알고리즘에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.3
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    • pp.735-741
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    • 2014
  • Edge in images appears when a great difference shows up in light and shade between pixels and includes data of the subject's size, location direction and etc. The edge is generally detected by the methods such as Sobel, Roberts, Laplacian, LoG(Laplacian of Gaussian) and etc. However, in AWGN(additive white Gaussian noise) added images, quality of the edge becomes slightly uncertain. Therefore, this paper proposed edge detection algorithm using modified mask of weighting to improve the quality of the existing methods. And in order to verify the performance efficiency of the proposed method, processed image and PFOM(Pratt's figure of merit) has been used as valuation standard for a comparison with the existing methods.

A Study on Edge Detection Algorithm in Salt & Pepper Noise Environments (Salt & Pepper 잡음 환경에서 에지 검출 알고리즘에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.8
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    • pp.1973-1980
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    • 2014
  • Edge detection for such as image, lane and object recognition is important image processing method. And some traditional method for this, there are Sobel, Prewitt, Roberts, Laplacian, LoG(Laplacian of Gaussian) and so on. Characteristics of these methods are insufficient in the salt & pepper noise added image. In order to improve such a problem of conventional methods, in this paper, we proposed an algorithm applying the weighted mask for detecting an edge by setting the local mask centered on the adjacent of the central pixel if central pixel of the mask is non-noise, it is intactly set by element of estimated mask, after calculating estimated mask if it is noise.

An Algorithm on Edge Detection using Local Mask in Salt & Pepper Noise Environments (Salt & Pepper 잡음 환경에서 국부 마스크를 이용한 에지 검출에 관한 연구)

  • Lee, Chang-Young;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2014.05a
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    • pp.787-789
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    • 2014
  • Image processing is presently used in various areas such as smart phone, smart TV, and portable PC. Likewise, edge detection plays an important role in most of the applications. As such, studies for the detection of edge are continually underway. Roberts, Laplacian and LoG(lapacian of Gaussian) are the representative edge detection methods, but these methods do not offer optimal edge detection characteristic in case of the image that is damaged by Salt & Pepper noises. As such, this study presented algorithm with superior edge detection characteristic by utilizing the elements of local mask in Salt & Pepper noise environment.

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Algebraic Attacks on Summation Generators (Summation Generator에 대한 대수적 공격)

  • Lee, Dong-Hoon;Kim, Jae-Heon;Han, Jae-Woo;Hong, Jin;Moon, Duk-Jae
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.14 no.1
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    • pp.71-77
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    • 2004
  • It was proved that Hen is an algebraic ,elation of degree [n(l+1]/2] for an (n, 1)-combine. which consists of n LFSRs and l memory bits. For the summation generator with $2^k$ LFSRs which uses k memory bits, we show that there is a non-trivial relation of degree at most $2^k$ using k+1 consecutive outputs. In general, for the summation generator with n LFSRs, we can construct a non-trivial algebraic relation of degree at most 2$^{{2^{[${log}_2$}n]}}$ using [${log}_2$+1 consecutive outputs.

Edge Detection based on Contrast Analysis in Low Light Level Environment (저조도 환경에서 명암도 분석 기반의 에지 검출)

  • Park, Hwa-Jung;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.05a
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    • pp.437-440
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    • 2022
  • In modern society, the use of the image processing field is increasing rapidly due to the 4th industrial revolution and the development of IoT technology. In particular, edge detection is widely used in various fields as an essential preprocessing process in image processing applications such as image classification and object detection. Conventional methods for detecting an edge include a Sobel edge detection filter, a Roberts edge detection filter, a Prewitt edge detection filter, Laplacian of Gaussian (LoG), and the like. However, existing methods have the disadvantage of showing somewhat insufficient performance of edge detection characteristics in a low-light level environment with low contrast. Therefore, this paper proposes an edge detection algorithm based on contrast analysis to increase edge detection characteristics even in low-light level environments.

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A Study on Edge Detection Considering Center Pixels of Mask (마스크의 중심 화소를 고려한 에지 검출에 관한 연구)

  • Park, Hwa-Jung;Jung, Hwae-Sung;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2022.10a
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    • pp.136-138
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    • 2022
  • Edge detection includes information such as the shape, position, size, and material of an object with respect to an image, and is a very important factor in analyzing the characteristics of the image. Existing edge detection methods include Sobel edge detection filter, Roberts edge detection filter, Prewitt edge detection filter, and LoG (Lapacian of Gaussian) using secondary differentials. However, these methods have a disadvantage in that the edge detection results are somewhat insufficient because a fixed weight mask is applied to the entire image area. Therefore, in this paper, we propose an edge detection algorithm that increases edge detection characteristics by considering the center pixel in the mask. In addition, in order to confirm the proposed edge detection performance, it was compared through simulation result images.

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