• 대한원격탐사학회지
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• 제14권3호
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• pp.250-261
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• 1998

본 논문에서는 위성 영상을 이용하여 고속으로 수치지형표고 모델을 추출하기 위한 방법을 제안한다. 수치지형표고 모델 추출 방법은 위성의 위치와 자세를 계산하는 카메라 모델링 과정, 스테레오 영상으로부터 동일점을 찾아내는 정합과정 그리고 외부 표정 요소와 정합쌍을 이용하여 고도 정보를 추출하는 고도 정보 계산 과정으로 크게 구분된다. 이 중 정합 과정은 대상 영상의 모든 영역에 대하여 수행되므로 계산량이 많고, 수치지형표고 모델 추출 과정의 대부분의 수행시간을 점유한다. 따라서 본 논문에서는 수치지형표고 모델 추출 과정 중 대부분의 수행시간을 차지하는 정합 기법의 속도 향상을 통하여 수치지형표고 모델 제작 시간을 단축 시킨다. 본 논문에서 제안한 정합 기법의 속도 향상 방법은 두 가지로 분류된다. 첫째는 일반적으로 많이 사용되는 유사함수인 정규상관계수(NCC: Normalized Cross Correlation)에 비해 계산량이 적은 고속 GC(Gradient Correlation)을 사용한다. 둘째는 동일점을 찾기 위하여 사용되는 정합 창틀을 계산할 때, 이전에 미리 계산된 값을 이용하여 계산량을 감소시킨다. 실험에 사용한 입력 영상은 6000$\times$6000 크기의 충청 지역 level 1A SPOT위성 쌍의 일부분이다 실험 결과 기존의 수치지형표고 모델 추출 방법과 유사한 성능을 보이며 수행시간이 단축되는 것을 확인하였다.

• 정보처리학회논문지B
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• 제12B권2호
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• pp.115-122
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• 2005

영상이 다른 영상을 포함하고 있는 경우, 이득 영상의 인치 여부를 판단하는 부분 영상 매칭 방법은 대부분 자연 영상을 대상으로 연구되고 있다. 본 논문에서는 자연 영상이 아닌 텍스트 영상을 매칭하는데 효과적인 두 가지 기법, 즉 메쉬 기반 방법과 상관성 기반 방법을 제안하고자 하다. 메쉬 기반 방법은 두 영상의 일치하는 모서리론 찾은 후 겹치는 영역에 대한 메쉬 특징을 이용하여 유사 여부를 판단하는 것으로, 일치 영역 검색 단계와 유사성 측정 단계로 구성된다. 상관성 기반 방법은 FFT를 이용하여 두 영상의 상관성을 계산함으로써 유사도를 측정한다. 우편 자동화 시스템에서 텍스트 영상을 검증하는 분야에 세안 방법을 적용한 견과, 메쉬 기반 방법은 $90.1\%$, 상관성 기반 방법은 $92.7\%$의 성능을 나타내었다.

• 한국환경과학회지
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• 제23권3호
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• pp.399-407
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• 2014

In this study, before and after sunset carbon dioxide concentration and air temperature were observed in two points of atmosphere (lower observation point of the GL + 0.1 m, the upper observation point of GL + 1.0 m) on the foreshore at located in Suncheon Bay and their variations were analyzed. Observation was performed on the foreshore on 2~4 August 2010. Instrument (VAISALA, GMP343) was set two hours before sunset and then observation was made continuously for six hours. In three days, observed carbon dioxide concentration was 375~419 ppm, and the air temperature was in the range of $28.7{\sim}32.5^{\circ}C$. The average concentration of carbon dioxide was 388~399 ppm in the upper observation point and 386~396 ppm in the lower observation point. It was higher in the upper observation point and its fluctuations were similar in two observation points. Correlation coefficients between carbon dioxide concentration and air temperature in the upper observation point were in the range of -0.64~-0.88, and were calculated -0.65 to -0.90 in the lower observation point. For the carbon dioxide concentration, correlation coefficients between the upper part and the lower part were very high as 0.98 in three times. For the air temperature, correlation coefficients between the upper part and the lower part were very high as 0.97 and 0.99. In the same observation time, the slope of the linear regression function as carbon dioxide concentration in the lower observation point for the upper observation point was in the range of 0.97~1.01. Carbon dioxide concentration was slightly higher in the upper observation point. Because carbon dioxide in the lower observation point was closer on the surface of the foreshore and absorbed from atmosphere to the foreshore. In this study, it was showed that the vertical variation of carbon dioxide concentration was insignificant in the several meter scale of atmosphere on the surface of the foreshore.

• 농업과학연구
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• 제40권2호
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• pp.163-167
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• 2013

Objective of the study was to compare reflectance spectrum in the blade and the vein parts of cabbage and kale leaves. A total 6 cabbage and kale leaves were taken from a plant factory in Chungnam National University, Korea. Spectra data were collected with a UV/VIS/NIR spectrometer (model: USB2000, Ocean Optics, FL, USA) in the wavelength region of 190 - 1130 nm. Median filter smoothing method was selected to preprocess the obtained spectra data. We computed reflectance difference by subtraction of averaged spectrum from individual spectrum. To estimate correlation at different parts of cabbage and kale leaves, cross - correlation method was used. Differences between cabbage and kale leaves are clearly manifested in the green, red and near - infrared ranges. The percent reflectance of cabbage leaves in the NIR wavelength band was higher than that of kale leaves. Reflectance in the blade part was higher than in the vein part by 18%. Reflectance difference in the different parts of cabbage and kale leaves were clear in all of the wavelength bands. Standard deviation of reflectance difference in the vein part was greater for kale, while the value in the blade part was greater for cabbage leaves. Standard deviation of cross - correlation increased from 0.092 in the first sensor (UV/VIS) and 0.007 in the second sensor (NIR) to 0.099 and 0.015, respectively.

• 대한치과교정학회지
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• 제53권6호
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• pp.358-364
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• 2023

Objective: This study aimed to three-dimensionally evaluate the pharyngeal airway space (PAS) of patients with anterior open bite (AOB) by using cone-beam computed tomography (CBCT) and compare the findings with those obtained in individuals with normal occlusion. Methods: The open bite group (OBG, n = 25) consisted of patients with an anterior overbite of -3 mm or less, while the control group (n = 25) consisted of age- and sex-matched individuals with an anterior overbite of 1-3 mm, Angle Class I malocclusion (1° ≤ point A-nasion-point B angle ≤ 4°), and a normodivergent profile (22° ≤ Frankfort mandibular plane angle ≤ 28°). After the CBCT data were reconstructed into a three-dimensional image, the PAS was segmented into four parts, and the volume of each part was measured. Pharyngeal airway length (PAL) and the area and transverse width of the part showing minimal constriction were also measured. Pearson's correlation analysis was used to evaluate the correlation between changes in the PAS and the amount of anterior overbite. Results: The OBG showed a significantly narrower airway space in the nasopharyngeal, hypopharyngeal, and total airway volumes. The OBG also showed a significantly smaller area and transverse width of the part with minimal constriction. The OBG showed a significantly longer PAL, but there was no correlation between the amount of anterior overbite and the changes in PAS. Conclusions: The PAS was associated with AOB. Patients with AOB had a narrower PAS and a smaller part showing minimal constriction.

• Journal of Information Technology Applications and Management
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• 제22권3호
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• pp.105-114
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• 2015

This paper presents a fast Time Difference of Arrival (TDOA) estimation for sound source localization. TDOA is the time difference between the arrival times of a signal at two sensors. We propose a partial cross correlation method to increase the speed of TDOA estimation for sound source localization. We do this by predicting which part of the cross correlation function contains the required TDOA value with the help of the signal energies, and then we compute the cross correlation function in that direction only. Experiments show approximately 50% reduction in the cross correlation computation time thereby increasing the speed of TDOA computation. This makes it very relevant for real world surveillance.

• 자원환경지질
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• 제33권3호
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• pp.217-228
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• 2000

We use spectral correlation method to analyze gravity and magnetic anomalies of Euiseong Sub-basin for distribution of rock facies and gelogic structures. The analysis reveals distinct polarity between gravity and magnetic anomaly correlation ; intermediate to mafic intrusives, extrusives, and the Tertiary basin shows positive gravity (+G) and positive magnetic (+M) correlation. Granitic gneiss and felsic volcanics negative gravity 9-G) and negative magnetic (-M) correlation. The Palgongsan granite, felsic to mafic extrusives and Mesozoic granites are characterized by -G and + M correlation. +G and -M correlations in the sedimentary formations are interpreted by uplift of pre-Cretaceous basement rocks . The + G and + M correlation characteristics in northeastern part of Euiseong Sub-basin including the Tertiary sedimentary basin result from the uplift of crustal materials. Major axes of spectrally correlated amomalies have mostly NW-SE or NE-SW directions. The former is due to the intrusives along strike-slip faults, and the latter which is observed in sedimentary formations is related to geological structures of basement associated new insight into the boundary between Euiseong and Milyang Sub-basin.

• 한국항공우주학회지
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• 제37권9호
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• pp.916-922
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• 2009

우주공간에서 임무를 수행하는 인공위성의 열설계는 열모델을 활용한 열해석 결과를 바탕으로 수행되므로, 열모델의 정확성은 매우 중요하며 이것은 보정과정을 통하여 향상된다. 열모델의 보정은 인공위성이 열진공 챔버에 장착된 형상을 모사하는 모델링에서 시작하여 실제형상과 열모델간의 일치성에 대한 검증, 거시적 변수에서부터 미시적 변수에 이르기까지 열모델 변수에 대한 조정 등을 거쳐 주어진 성공 조건을 만족할 때까지 열모델을 지속적으로 수정하는 과정으로 이루어진다. 본 연구에서는 열모델 보정의 성공 기준을 수립하고 인공위성 열-구조 모델 열진공 시험결과를 활용한 열모델 보정을 수행하여 보정 기준을 충족시켰다. 본 연구에서 보정이 완료된 열모델은 저궤도 인공위성 상세 열설계에 적용될 수 있었다.

• 한방안이비인후피부과학회지
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• 제20권1호통권32호
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• pp.228-238
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• 2007

Objectives ; Sasang Constitional Medicine is a part of Korean traditional Medicine, and classify human constitution into four types. Scalp and hair is a part of skin. Skin is one of constitutional charasteristic element. So we researched a correlation between Sasang constitutions and Korean adult scalp and hair condition. This is a basic study to find constitution can be a important factor to care scalp and hair. Methods ; We examined Sasang constitutions and scalp and hair condition of 80 human who aged from 20-50. Scalp disease, dandruff was observed by video micro scope and sebum tape diagnosis. Thickness of hair was measured by Laser Scan Micrometer(LSM-3100). Itching sense and life habit was also investigated. Constitution diagnosis and scalp, hair diagnosis was investigated seperately as a blind test and the data was statistically analyzed with chi-square test, correlation analysis, one-way analysis of varience. Results ; 1. In Sasang Constitution, Taeumin group had significant tendency of oilily scalp. 70% of Taeumin group had oilily scalp. 2. The group of dry or oilily scalp had more itching sense and more sensativity of scalp compaired to neuter scalp group. 3. There was no correlation between height, weight, thickness of hair, itching sense, scalp disease and Sasang constitution. 4. There was correlation between loss of hair and drinking alcohol, obesity, curly hair, soft scalp. Conclusions ; Korean adult scalp and hair condition had correlation with Sasang constitution.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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• pp.208-211
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• 2004

Landmark matching is one of an important algorithm for navigation of satellite images. This paper proposes a fast landmark matching algorithm using a MGLI (Moving Guide-Line Image). For searching the matched point between the landmark chip and a part of image, correlation matrix is used generally, but the full-sized correlation matrix has a drawback requiring plenty of time for matching point calculation. MGLI includes thick lines for fast calculation of correlation matrix. In the MGLI, width of the thick lines should be determined by satellite position changes and navigation error range. For the fast landmark matching, the MGLI provides guided line for a landmark chip we want to match, so that the proposed method should reduce candidate areas for correlation matrix calculation. This paper will show how much time is reduced in the proposed fast landmark matching algorithm compared to general ones.