• 한국산림과학회지
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• 제19권1호
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• pp.49-54
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• 1973

면적(面積)이 광대(廣大)하며 지형(地形)은 험준(險峻)한 산림(山林)에서 그의 축적(蓄積)을 조사(調査)하기에는 여러 난점(難點)이 많다. 중량(重量)과 용적(容積)에 비(比)하여 그 가격(價格)이 저렴(低廉)한 임목(林木)의 축적(蓄積)을 조사(調査)하는데 많은 시간(時間)과 노력(勞力)을 소비(消費)함은 산림경영상(山林經營上) 아주 비경제적(非經濟的)이다. 그러므로 항공사진(航空寫眞)만을 가지고 용이(容易)하게 ha 당(當) 임분재적(林分材積)을 추정(推定)할 수 있도록 임분재적표(林分材積表)를 작성(作成)하고 임분재적(林分材積)과 관련(關聯)있는 인자(因子)의 재적추정(材積推定)에의 관여성(關與性)을 구명(究明)하였다. 재료(材料)는 임업시험장(林業試驗場) 광릉시험림내(光陵試驗林內)에 식재(植栽)한 잣나무림(林) 114개소(個所)이며 근래(近來)에 발달(發達)한 통계학(統計學)의 일종(一種)인 다변량해석(多變量解析)과 수량화(數量化)의 이론(理論)을 응용(應用)하였으며 계산(計算)은 한국과학기술연구소(韓國科學技術硏究所)(K.I.S.T.)의 전자계산기연구실(電子計算機硏究室)에서 행(行)하였다. 조제(調製)된 임분재적표(林分材積表)의 중상관계수(重相關係數)는 0.85~0.88 로 상당(相當)히 높은 정확도(正確度)를 갖고 있다.

• Journal of Forest and Environmental Science
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• 제24권3호
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• pp.165-169
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• 2008

This study attempts to analyze the relationship between forest volume and age based on 5th NFI data and spectral characteristics of satellite imagery using ASTER sensor in Korea. Forest stand volume and age had the negative correlation with the spectral reflectance in all of the band (Blue, Green, Red, SWIR). With increasing of stand volume and age, spectral reflectance decrease. The spectral reflectance of band1 showed the highest correlation between stand volume and spectral reflectance among the VNIR wavelength. The spectral reflectance band 1, 2 (visible wavelength) and stand age have high correlation compared to other bands. The correlation coefficients between forest volume and vegetation indices have low relationship. This result indicates that the reflectance of blue band may be important factor to improve the potential of optical remote sensing data to estimate forest volume and age.

• Interdisciplinary Bio Central
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• 제3권3호
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• pp.11.1-11.5
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• 2011

The MRI (magnetic resonance imaging) volumetric analysis of the brain was performed in 59 healthy elderly Koreans (aged 62-76 years; 34 male, 25 female) to investigate whether the previously reported significant correlations between body height and brain volumes in the young aged Koreans (20's) still exist in the old aged Koreans (60's and 70's). Unlike previously reported significant correlations in the young aged Koreans, neither the correlation between whole brain volume and body height in male nor the correlation between cerebellar volume and body height in female show any significance in the old aged Koreans. The significant correlation between body height and whole brain volume was still observed when both male and female data were combined (r=0.27, P<0.05), but the correlation coef-ficient and the level of significance markedly decreased from those of previously reported Korean youth data (r=0.67, P<0.01). Simple linear regression analysis shows decrease of explanatory power of height (measured in $r^2$) from 44% in the youth group to 7% in the old age group on the variance of whole brain volume. Multiple linear regression analysis shows that age and sex, rather than height, are major explanatory variables for whole brain volume in the old aged Koreans. The loss of correlations in the aged group is suspected to be mainly due to age related brain volume changes.

• 보건행정학회지
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• 제24권3호
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• pp.271-282
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• 2014

Background: Although the mortality rate in cancers has been decreased recently, it is still one of the leading causes of death in most of the countries. This study analyzed the relationship between surgery volume and in hospital mortality of cancer patients. The purpose of this study is to investigate the relationship in Korean healthcare environment and to provide information for the policy development in reducing cancer mortality. Methods: The study sample was the 20,517 cancer patients who underwent surgery and discharged during a month period between 2008-2011. The data were collected in Patient Survey by Korean Institute of Social Affairs. Logistic regression was used to analyse a comprehensive analytic model that includes a binary dependent variable indicating death discharge and independent variables such as surgery volume, organizational characteristics of hospitals, socio-economical characteristics of the patients, and severity of disease indicators. Results: In chi-square test, as the surgery volume increases, the in-hospitals mortality showed a downward trends. In regression analysis, the relationship between surgery volume and mortality showed significant negative associations in all types of cancer except for pancreatic cancer. Conclusion: In the absence of other information patients undergoing cancer surgery can reduce their risk of operative death by selecting a high-volume hospital. Therefore, policies to enhance centralization of cancer surgery services should be considered.

• Computers and Concrete
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• 제25권4호
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• pp.303-310
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• 2020

In this research, a hybrid mathematical model is derived using the higher-order polynomial kinematic model in association with soft computing technique for the prediction of best fiber volume fractions and the minimal mass of the layered composite structure. The optimal values are predicted further by taking the frequency parameter as the constraint and the projected values utilized for the computation of the eigenvalue and deflections. The optimal mass of the total layered composite and the corresponding optimal volume fractions are evaluated using the particle swarm optimization by constraining the arbitrary frequency value as mass/volume minimization functions. The degree of accuracy of the optimal model has been proven through the comparison study with published well-known research data. Further, the predicted values of volume fractions are incurred for the evaluation of the eigenvalue and the deflection data of the composite structure. To obtain the structural responses i.e. vibrational frequency and the central deflections the proposed higher-order polynomial FE model adopted. Finally, a series of numerical experimentations are carried out using the optimal fibre volume fraction for the prediction of the optimal frequencies and deflections including associated structural parameter.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제9권6호
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• pp.646-661
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• 2003

웹환경에서 모든 클라이언트 컴퓨터에 방대한 볼륨데이타를 저장하여 놓고 이것을 인터랙티브하게 가시화하는 것은 쉽지 않다. 한 가지 해결 방법은 볼륨데이타를 압축하여 데이타베이스 서버에 보관하여 놓고 요구에 맞추어 네트워크를 통하여 클라이언트 컴퓨터에 전송하여 가시화하는 것이다. 이러한 경우 압축에 많이 사용하는 알고리즘이 웨이블릿 변환이다. 이 논문에서는 서버 컴퓨터에서 볼륨데이타를 웨이블릿 알고리즘을 이용하여 압축하여 놓고 클라이언트 컴퓨터로 전송하여 디렉트볼륨렌더링하는 패러다임에 적합한 웨이블릿과, 압축률을 구하기 위한 실험을 한다. Engine, CThead, Bentum 볼륨데이타를 Har, Daubechies4, 12, 20 웨이블릿을 이용하여 각각 전체 데이타의 50%, 10%, 5%, 1%, 0.1%, 0.03%로 압축하여 디렉트볼륨렌더링을 이용하여 가시화한 후 육안 및 영상평가지표를 이용하여 평가하였다. 성능은 압축률이 낮은 범위에서는 Harr 웨이블릿이 우수하였고 압축률이 높은 곳에서는 Daubechies4와 Daubechies12 웨이블릿이 우수하였다. 바람직한 압축률은 육안으로 평가한 경우는 전체 데이타의 약 1%이고 영상평가지표를 이용하여 평가한 경우는 전체 데이타의 약 5-10%이었다.

• 한국측량학회지
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• 제38권2호
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• pp.131-140
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• 2020

Recently the importance of BIM (Building Information Modeling) that enables 3D location-based design and construction work is being highlighted around the world. In Korea, the road map has been established to settle the design based on BIM using drone survey results by 2025. As the first step, BIM would be applied to road construction projects worth more than 50 billion Korean Won from 2020. On the other hand, drone survey regulation has been enacted and the data for drone survey cost were also included on Standard of construction estimate in 2020. However, more careful improvement is required to reflect drone survey results in BIM design and construction. Currently, Engineering instructions and Standard of construction estimate specifies that earthwork volume must be calculated by cross section method only. So it is required to add the method of DEM (Digital Elevation Model) based volume calculation on these regulations to realize BIM application. In order for that, this study verified the method of DEM based earthwork volume calculation. To get an accurate DEM for accurate volume computation, drone survey was carried out according to the drone survey regulation and then could get an accurate DEM data which have errors less than 3cm in X, Y and 6.8cm in H. As each DEM cell has 3D coordinate component, the volume of each cell can be calculated by obtaining the height of area of the cell then total volume is calculated by multiplying total number of cells by volume of each cell for the construction area. Verification for the new calculation method compare with existing method was carried out. The difference between DEM based volume by drone survey and cross section based volume by traditional survey was less than 1.33% and it can be seen that new DEM method will be able to be applied to BIM design and construction instead of cross section method.

• 한국지리정보학회지
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• 제13권4호
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• pp.138-147
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• 2010

부정확한 교통량 예측은 잘못된 교통계획 및 설계를 초래할 수 있으므로, 교통량 데이터를 이용한 교통량 예측은 교통계획 및 운영과 같은 공간의사결정과정에서 매우 중요하다. 교통량 예측의 정확도 향상을 위해 최근 공간통계분석방법인 크리깅 방법론을 이용한 연구들이 발표되고 있으며, 연구결과 기존의 전통적인 방법에 비하여 예측력이 높게 나타났다. 이에 본 연구는 먼저 미국 미주리 주의 세인트루이스를 대상으로 크리깅 분석방법론을 이용하여 교통량 데이터를 예측한 후 실제 측정값과 비교하여 그 정확도를 검증하였다. 이후 크리깅 방법론의 예측 값을 더욱 향상 시키기 위한 새로운 방안을 제시하였다. 그 방안으로 첫째, 베리오그램 인자 결정시 나타난 교통량 데이터의 특징인 이방성을 적용하였으며, 둘째, 교통량 데이터의 공간적 상관관계가 높은 주간고속도로를 이차변수로 설정하여 공동크리깅 분석을 실시하였다. 분석결과 일반 크리깅 방법보다 이방성을 적용한 분석에서 더욱 높은 정확도 나타났으며, 이방성의 적용 하에 실시한 공동크리깅의 결과에서 가장 좋은 예측 값이 나타났다.

• 한국환경복원기술학회지
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• 제6권4호
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• pp.52-61
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• 2003

This study was carried out to analyze the effects of stormwater retention and infiltration pond on reduction of flood peak and volume in a experimentally developed ecological pond. The experimental site has 542$m^2$ watershed area, 1,310mm yearly-averaged rainfall. And the area of the retention pond is 60$m^2$, the maximum water depth is 0.5m, the maximum and average storage is 15$m^3$and 9.3$m^3$d. And the area of infiltration pond is 58$m^2$, and the water depth varies 0.2m~0.5m. The monitoring system consists of one rainfall gage, one Parshall flume and acoustic water level gage, two rectangular weirs and acoustic water level gage for discharge gaging, and one data recording unit. Data from ten storm events in total, three storm events in year 2000 and seven storm events in year 2001, were collected. From the data the evaporation rate was achieved with the water balance equation, and the result shows 5.0mm/day in average. The result from the analysis of the effects on reduction of flood peak and volume, is that 14% reduction of flood volume and 15% reduction of flood peak in retention pond and 49% reduction of flood volume in infiltration pond.

• 한국빅데이터학회지
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• 제4권1호
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• pp.29-38
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• 2019

본 연구에서는 판매량 증대와 효율적인 재고 관리를 위해 지난 5년간 온라인 쇼핑몰 'A'에서 누적된 빅데이터를 활용하여 기온 변화에 따른 반팔 티셔츠와 아우터웨어(outer wear)의 판매량을 예측하는 판매 예측 모델을 제안한다. 제안한 모델은 2014년부터 2017년도까지 기온 변화에 따른 반팔 티셔츠와 아우터웨어의 판매량을 분석하여 2018년 기온 변화에 따른 반팔티셔츠와 아우터웨어의 판매량을 예측한다. 제안한 판매 예측 모델을 사용하여 반팔티셔츠와 아우터웨어의 판매량 예측값과 실제 2018년 판매량을 비교 분석한 결과 반팔티셔츠와 아우터웨어의 예측 오차율은 각각 ±1.5%와 ±8%를 나타내었다.