문무잡과(文武雜科) 방목(榜目)의 의사학적(醫史學的) 가치(價値)

유희영 대한한방신경정신과학회 1990 동의신경정신과학회지 Vol.1 No.1

Selecting Optimal Basis Function with Energy Parameter in Image Classification Based on Wavelet Coefficients

유희영,이기원,진홍성,권병두 대한원격탐사학회 2008 大韓遠隔探査學會誌 Vol.24 No.5

Land-use or land-cover classification of satellite images is one of the important tasks inremote sensing application and many researchers have tried to enhance classification accuracy. Previousstudies have shown that the classification technique based on wavelet transform is more effective thantraditional techniques based on original pixel values, especially in complicated imagery. Various basisfunctions such as Haar, daubechies, coiflets and symlets are mainly used in 2D image processing based onwavelet transform. Selecting adequate wavelet is very important because different results could be obtainedaccording to the type of basis function in classification. However, it is not easy to choose the basis functionwhich is effective to improve classification accuracy. In this study, we first computed the wavelet coefficientsof satellite image using ten different basis functions, and then classified images. After evaluating classificationresults, we tried to ascertain which basis function is the most effective for image classification. We also triedto see if the optimum basis function is decided by energy parameter before classifying the image using allbasis functions. The energy parameters of wavelet detail bands and overall accuracy are clearly correlated.The decision of optimum basis function using energy parameter in the wavelet based image classification isexpected to be helpful for saving time and improving classification accuracy effectively.

The Impacts of Decomposition Levels in Wavelet Transform on Anomaly Detection from Hyperspectral Imagery

유희영,박노욱 대한원격탐사학회 2012 大韓遠隔探査學會誌 Vol.28 No.6

In this paper, we analyzed the effect of wavelet decomposition levels in feature extraction for anomaly detection from hyperspectral imagery. After wavelet analysis, anomaly detection was experimentally performed using the RX detector algorithm to analyze the detecting capabilities. From the experiment for anomaly detection using CASI imagery, the characteristics of extracted features and the changes of their patterns showed that radiance curves were simplified as wavelet transform progresses and H bands did not show significant differences between target anomaly and background in the previous levels. The results of anomaly detection and their ROC curves showed the best performance when using the appropriate sub-band decided from the visual interpretation of wavelet analysis which was L band at the decomposition level where the overall shape of profile was preserved. The results of this study would be used as fundamental information or guidelines when applying wavelet transform to feature extraction and selection from hyperspectral imagery. However, further researches for various anomaly targets and the quantitative selection of optimal decomposition levels are needed for generalization.

자료 : 이석간 경험방 ③

유희영 대구한의대학교 제한동의학술원 1977 황제의학 Vol.2 No.2

고해상도 다중시기 위성영상을 이용한 밭작물 분류: 마늘/양파 재배지 사례연구

유희영,이경도,나상일,박찬원,박노욱,Yoo, Hee Young,Lee, Kyung-Do,Na, Sang-Il,Park, Chan-Won,Park, No-Wook 대한원격탐사학회 2017 大韓遠隔探査學會誌 Vol.33 No.5

이 논문에서는 고해상도 다중시기 위성영상을 이용한 밭작물 재배지 분류 가능성을 확인하기 위해 마늘과 양파 주산지를 대상으로 분류를 수행하였다. 마늘과 양파의 생육주기에 맞춰 영상을 수집하고 단일시기와 다양한 다중시기 자료의 조합으로 분류를 시도하였다. 단일시기 자료의 경우 파종이 모두 끝난 시기인 12월과 작물이 활발히 자라기 시작하는 3월 영상을 이용하였을 때 높은 분류 정확도를 보였다. 한편, 단일시기 자료 보다는 다중시기 자료를 이용하였을 때 더 높은 분류 정확도를 보였는데 자료의 수가 많은 것이 무조건 높은 분류 정확도를 반영하지는 않았다. 오히려 파종 시기 또는 파종 직후의 영상은 분류 정확도를 떨어뜨리는 역할을 하였고 마늘과 양파의 성장기인 3, 4, 5월 영상을 동시에 이용하여 분류하였을 때 가장 높은 분류 정확도를 얻었다. 따라서, 다중시기 위성영상을 이용하여 마늘과 양파를 분류하기 위해서는 작물 주요 성장기의 영상 확보가 매우 중요하다는 것을 확인할 수 있었다. In this paper, a study on classification targeting a main production area of garlic and onion was carried out in order to figure out the applicability of multi-temporal high-resolution satellite imagery for field crop classification. After collecting satellite imagery in accordance with the growth cycle of garlic and onion, classifications using each sing date imagery and various combinations of multi-temporal dataset were conducted. In the case of single date imagery, high classification accuracy was obtained in December when the planting was completed and March when garlic and onion started to grow vigorously. Meanwhile, higher classification accuracy was obtained when using multi-temporal dataset rather than single date imagery. However, more images did not guarantee higher classification accuracy. Rather, the imagery at the planting season or right after planting reduced classification accuracy. The highest classification accuracy was obtained when using the combination of March, April and May data corresponding the growth season of garlic and onion. Therefore, it is recommended to secure imagery at main growth season in order to classify garlic and onion field using multi-temporal satellite imagery.

위성영상 및 지구물리 영상자료의 호모몰픽 필터링 적용

유희영,이기원,권병두 한국지구과학회 2005 韓國地球科學會誌 Vol.26 No.1

Homomorphic filtering improves image by enhancing high components and reducing low components in the frequency domain based on FFT, as one of useful digital image processing techniques. In this study, the application program for homomorphic filtering was developed. Using this program, satellite imageries and geophysical image such as magnetic image data were processed and their results were analyzed. In case of applying to other techniques such as histogram equalization and kernel based masking for the same purpose, they often cause the slight distortion of boundary or overall change of brightness values on the whole image. Whereas, homomorphic filtering has ability to enhance selectively detailed components in a target image. Therefore, this technique can be effectively used for extraction or separation of complex types of characteristics contained in the satellite imagery. In addition, this technique would be applicable to investigate anomalous zone in various geophysical image data.

백금환(白金丸)의 효능(效能)에 관(關)한 실험적(實驗的) 연구(硏究)

유희영,강형욱 대한한방신경정신과학회 1990 동의신경정신과학회지 Vol.1 No.1

원격탐사 자료 기반 지형공간 특성분석을 위한 텍스처 영상 비교와 템플레이트 정합의 적용

유희영,전소희,이기원,권병두 한국지구과학회 2005 韓國地球科學會誌 Vol.26 No.7

As remote sensing imagery with high spatial resolution (e.g. pixel resolution of 1 m or less) is used widely in the specific application domains, the requirements of advanced methods for this imagery are increasing. Among many applicable methods, the texture image analysis, which was characterized by the spatial distribution of the gray levels in a neighborhood, can be regarded as one useful method. In the texture image, we compared and analyzed different results according to various directions, kernel sizes, and parameter types for the GLCM algorithm. Then, we studied spatial feature characteristics within each result image. In addition, a template matching program which can search spatial patterns using template images selected from original and texture images was also embodied and applied. Probabilities were examined on the basis of the results. These results would anticipate effective applications for detecting and analyzing specific shaped geological or other complex features using high spatial resolution imagery. 공간해상도 1m 이하의고해상도원격탐사영상의민간활용이활발해짐에따라, 이를위한전문분야별영상분석방법의개발요구가증가하고있다. 다양한영상분석기법중에, 주변화소들간의공간분포관계에의해특성이결정되는텍스처영상의분석은이러한목적을위한유용한영상분석방법중하나이다. 이연구에서는원시영상으로부터 GLCM 알고리즘에의해생성된텍스처영상에대해서방향인자, 마스킹커널의크기, 변수의종류에따른결과를비교, 분석한뒤각의결과영상의지형공간특성분석의적용성에대하여알아보았다. 또한원시영상과텍스처영상에서특성정보를포함하는템플레이트를설정하고이를기준으로반복적인패턴을자동으로검색하는템플레이트정합프로그램을구현하여이를원시영상과텍스처영상에적용하였고, 처리결과에기초하여향후적용가능성을검토하였다. 이연구의결과는일정한패턴으로나타나는지구과학적인지형특성이나고해상도위성영상정보를이용한인공지형지물의파악및분석에효과적으로적용될수있을것으로예상된다.

A Comparative Study of 3D DWT Based Space-borne Image Classification for Differnet Types of Basis Function

유희영,이기원,권병두 대한원격탐사학회 2008 大韓遠隔探査學會誌 Vol.24 No.1

In the previous study, the Haar wavelet was used as the sole basis function for the 3D discrete wavelet transform because the number of bands is too small to decompose a remotely sensed image in band direction with other basis functions. However, it is possible to use other basis functions for wavelet decomposition in horizontal and vertical directions because wavelet decomposition is independently performed in each direction. This study aims to classify a high spatial resolution image with the six types of basis function including the Haar function and to compare those results. The other wavelets are more helpful to classify high resolution imagery than the Haar wavelet. In overall accuracy, the Coif4 wavelet has the best result. The improvement of classification accuracy is different depending on the type of class and the type of wavelet. Using the basis functions with long length could be effective for improving accuracy in classification, especially for the classes of small area. This study is expected to be used as fundamental information for selecting optimal basis function according to the data properties in the 3D DWT based image classification.

Arabidopsis BAK1 과발현이 Rice 성장에 미치는 영향

유희영,조은영,오유진,남경희 한국육종학회 2007 한국육종학회 학술발표회 발표요지 Vol.38 No.1