• 전자공학회논문지B
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• 제33B권5호
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• pp.118-126
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• 1996

In object analysis by image processing, finding lines plays a universal role. And these lines can be easily found by detecting ridges and valleys in digital gray scale images. In this paper, a new method of detecting ridges and valleys by using local min/max operations was presented. This method detects ridges and valleys of desired width by using erosion and dilation properties of local min/max operations, and requires no information of ridge or valley direction. Therefore the method is efficient and computationally simple in comparision with the conventional analytical method.

• 한국지형학회지
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• 제18권4호
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• pp.261-270
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• 2011

연구지역인 웅천천 유역은 차령산지의 남서쪽 말단부에 위치하여 황해와 맞닿아 있다. 본 연구는 지형 규모의 연계성 차원에서 차령산지에 발달한 지형선구조 체계가 국지적 시야의 연구지역 지형경관에 나타나는 바를 확인하여 기술·설명하고자 한다. 연구지역에서 확인되는 주요 지형선구조는 NE-SW, NNE-SSW, NNW-SSE, N-S, E-W 등의 방향이며, 그 중 NNE-SSW, NE-SW방향 선구조가 지형경관에 가장 뚜렷하게 반영되어 인식할 수 있다. 주요 산체와 곡지는 NNE-SSW 방향성을 지니며, NE-SW방향의 선구조 곡지는 비교적 규모가 크고, 저기복 구릉, 산록단구, 하안단구, 범람원 등의 다양한 지형요소가 발달하는 곳이 많다. 반면 NNW-SSE, N-S, E-W 방향 선구조 곡지는 대체로 좁고 깊지 않은 곡지로 나타나지만 선구조는 선명하게 유지하고 있다. 또한 연구지역의 선구조 곡지의 규모와 곡지를 흐르는 하천 차수 간에는 상관성이 없다.

• Journal of Advanced Marine Engineering and Technology
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• 제29권2호
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• pp.217-224
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• 2005

A new roof edge detection method based on multi level scales of wavelet function is proposed in this paper roof edge and its direction are obtained in this new methods at one time. Besides. scale characteristics of detecting roof edge is analyzed. And a few new methods on fingerprint image pre-processing are described. A method segmenting foreground/background of fingerprint images is proposed, in which Prior estimation of direction field is not required any more. A segmentation method based on multi-scale roof edges is implemented. and the valid scale range of the method is defined. too. And the method is used to segment ridges and valleys in fingerprint images simultaneously The exact direction fields made up of the direction of each point in ridges can be obtained when detecting ridges exactly based on the roof edge detector, in comparison with the traditional coarse estimation of direction fields. Obviously. it will establish a solid foundation for the sequent fingerprint identification.

• 대한환경공학회지
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• 제34권7호
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• pp.454-458
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• 2012

2005년부터 2010년까지 서부 경남지역 마을상수도 6,569건에 대한 지역별 수질특성, 항목별 수질특성, 수원별 수질특성 등의 수질 현황을 조사한 결과는 다음과 같다. 지역별 수질현황을 조사한 결과 불소의 평균농도는 함양지역이 0.19 mg/L, 질산성질소의 평균농도는 남해지역이 3.7 mg/L, 경도, 증발잔류물질, 황산이온의 평균농도는 의령지역이 177 mg/L, 271 mg/L, 80 mg/L로 각각 높게 나타났다. 계곡수를 취수원으로 사용하는 마을상수도는 일반세균, 탁도가 지하수를 취수원으로 사용하는 마을상수도보다 높게 검출되었으며, 지하수를 취수원으로 사용하는 마을상수도는 질산성질소, 증발잔류물, 경도, 황산이온, 불소, 철 등이 높게 검출되었다.

• 한국음향학회:학술대회논문집
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• 한국음향학회 1994년도 FIFTH WESTERN PACIFIC REGIONAL ACOUSTICS CONFERENCE SEOUL KOREA
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• pp.791-795
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• 1994

In this paper, the echo phenomena of Yingying Pagoda(ancient Chinese architecture), which may be resulted from interferences of reflection and diffraction by the pagoda eaves when pulse sound source is at some suitable positions, are investigated by an 1:2 scale model. There are valleys in frequency spectrum due to the interferences. On the other hand, taking eaves as wedges approximately, numerical spectral estimates are obtained from the closed-form impulse solution for diffraction of pulse point-source radiation by an infinite rigid wedge. The results of the numerical computations are similar to those of the model experiments. The study is a helpful guide to reconstruction or maintenance of this kind of ancient buildings.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.1374-1376
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• 2003

NASA, NSF and USGS jointly conducted a LIDAR survey over several sites in the Antarctic Dry Valleys and its vicinity, acquiring numerous surface points by NASA's Airborne Topographic Mapper (ATM) conical laser scanning altimetry system. The data set have high blunder ratio, and the conical scanning pattern resulted large variation of the point densities. Hence, to reduce the undesirable effects due to these characteristics and process the huge number of points with reasonable time and resources, we developed a novel approach to generate large-scale and high-resolution DEMs in robust, efficient and nearly automatic manners. Based on this approach we produced DEMs and then verified them with reference data.

• 한국지능시스템학회논문지
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• 제12권3호
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• pp.227-230
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• 2002

지문인식을 위한 중요한 전처리 과정중의 하나는 영상의 이진화 과정이다 이진화 과정은 그레이 레벨의 영상( gray scale input image)을 받아들여 이진의 영상(binary image)으로 만드는 것이다. 이진화 과정에 있어서의 어려운 점은 적절한 임계값(threshold value)을 찾는 것이다. 된 논문에서는 국부적인 융선과 골의 밝기의 특성에 따라 적절한 임계값을 선택하는 적응 이진화 방법을 제시한다. 실험을 통하여 게시된 방법은 기존의 방법과 비교하여 족은 성능을 보여주고 있음을 입증하였다.

• The Korean Journal of Ecology
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• 제12권3호
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• pp.145-160
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• 1989

Daehuksan Island (125°23'-125° 28' E and 34°37'-34°42' N, ca 19.7㎢) in the southwestern part of Mokpo, Korea, is a part of the Dadohae National Marine Park. Most of the actual vegetation of the island is substitutional vegetation under various human impact such as grazing, cutting for firewood. And natural vegetation is partially distributed in the tutelary shrine forests, deep valleys, etc. During 1987, phytosociological investigation of this was carried out on the basis of Braum-Blanguet's method. The forest vegetation was classified into 1 association and 7 communities, Camellia japonica, Machilus thunbergii, Ardisio-Castanopsietum sieboldii, Daphniphyllum macropodum-Quercus acuta, Pyrrosia lingua-Pinus densiflora. Rhododendron mucronulatum-Pinus thunbergii, Carpinus coreana, and Psedosasa japonica community. Grassland vegetation was classified into Gleichenia japonica, Gleichenia dichotoma, Arundinella hirta-Miscanthus sinensis, Artemisia princeps var. orientalis. Imperata cylindrica var. koenii Artemisia princeps var. orientalis-Pennisetum alpecuroides, Carex boottiana, and salt marsh vegetation. Thypa orientalis, Spergularia marina, Phragmites communis, Carex scabrifolia, and Triglochin maritimum community. Based on them, the actual vegetation map was made in 1:50,000 scale.

• Journal of the Optical Society of Korea
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• 제15권1호
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• pp.15-21
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• 2011

This paper proposes a new approach to palmprint verification based on the gradient, in which a palm image is considered to be a three-dimensional terrain. Principal lines and wrinkles make deep and shallow valleys on a palm landscape. Then the steepest slope direction in each local area is first computed using the Kirsch operator, after which an orientation map is created that represents the dominant slope direction of each pixel. In this study, three orientation maps were made with different scales to represent local and global gradient information. Next, feature matching based on pixel-unit comparison was performed. The experimental results showed that the proposed method is superior to several state-of-the-art methods. In addition, the verification could be greatly improved by fusing orientation maps with different scales.

• The Korean Journal of Ecology
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• 제13권3호
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• pp.181-190
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• 1990

Chodo Archipelago ($125^{\circ}$45 $-126^{\circ}$13 E and $34^{\circ}$15 $-34^{\circ}$25 N, ca. $56.7km^2$), a part of the Dadohae National Marine Park, largely is covered with substitutional vegetation under various human impact such as grazing, cutting for firewood. However natural vegetation is partially distributed in the tutelary shrine forests, deep valleys and etc. From October 1988 to June 1989, phytosociological investigation of this forest vegetation was carried out by Braun-Blanquet s method. The forest vegetation was classified into 1 association and 7 communities. Ardisio-Castanopsietum sieboldii, Machilus thunbergii, Quercus acuta, Litsea japonca, Eurya japonica-Pinus thunbergii mixed forest, Pinus densiflora, Pinus rigida afforestation. Carpinus coreana community. Based on the classification, the actual vegetation map was drawn in 1 : 50,000 scale.