• 한국수자원학회논문집
• /
• 제47권7호
• /
• pp.615-628
• /
• 2014

본 연구에서는 복하천 중상류 유역에 대해 유역수문모델 SWAT-K를 적용하여 1996년부터 2012년까지의 실제증발산량을 모의하여 연별, 월별 변동 특성을 분석하였으며, 유역물수지법으로 증발산량을 산정할 때 유역의 저류변화량 영향에 대해 고찰하였다. 대상유역의 연도별 실제증발산량은 최소 401mm에서 최대 494mm까지 발생하였고 평균적으로 강수량 대비 약 31%인 436mm 발생하였다. 월단위 실제증발산량은 모의기간동안 평균적으로 12월에 최소값 10mm, 7월에 최대값 84mm 발생한 것으로 분석되었다. 자료기간에 따른 연평균 저류변화량의 크기를 평가한 결과 강수량과 유츨량 자료만을 이용하여 유역물수지법으로 연평균 실제증발산량을 추정하기 위해서는 적어도 약 4~5년의 자료를 이용해야 적절한 것으로 분석되었다. 또한, 연구 대상유역에 대해 저류변화량을 고려하여 유역물수지법으로 연단위, 월단위 실제증발산량을 산정할 수 있도록 강수량에서 유출량을 감한 값과 저류변화량간의 선형의 관계식을 제시하였다.

• Architectural research
• /
• 제17권1호
• /
• pp.41-48
• /
• 2015

Early investigations focused mainly on manipulating the confinement effect to develop a reinforced concrete column with lateral hoops. Based on this legacy model, Li's model incorporated the additional confinement effect of a steel jacket. However, recent experiments on plain concrete cylinders with steel jackets revealed relatively large discrepancies in the estimates of strength enhancement and the post-peak behavior. Here, we describe a modified constitutive law for confined concrete with an unbonded external steel jacket in terms of three regions for the loading stage. We used a two-phase heterogeneous concrete model to simulate the uniaxial compression test of a $150mm{\times}300mm$ concrete cylinder with three thicknesses of steel jackets: 1.0 mm, 1.5 mm, and 2.0 mm. The proposed constitutive model was verified by a series of finite element analyses using a finite element program. The damaged plasticity model and extended Drucker-Prager model were applied and compared in terms of the level of pressure sensitivity for confinement in 3D. The proposed model yielded results that were in close agreement with the experimental results.

• Journal of the Korean Data and Information Science Society
• /
• 제27권2호
• /
• pp.429-435
• /
• 2016

일당증체량 (kg), 등지방두께 (mm), 90kg도달일령 (일), 등심깊이 (mm)와 정육율 (%)에 대한 유전력은 각각 0.40, 0.44, 0.40, 0.25와 0.48로 추정되었다. 모형 1과 모형 2에서 산육형질에 대한 육종가 및 순위간의 상관계수는 각각 0.995~1.000과 0.991~1.000의 범위에서 추정되었으며, 고도의 유의적인 수준 (p<0.0001)을 나타냄으로서 농장별로 추정된 육종가와 거의 일치하였다. 산육형질별 top 5%와 top 10%의 선발두수에 대한 농장별 상대적 선발비율은 그 동안 폐쇄축군을 유지하면서 각 농장들이 추구하는 개량형질에 따라서 현저히 다르게 나타났으며, 농장간 통합검정자료를 이용한 국가단위 유전능력평가 체계를 구축하여 우수 종돈을 선발하는 것이 더욱 바람직하다고 판단되었다.

• 한국방송∙미디어공학회:학술대회논문집
• /
• 한국방송∙미디어공학회 2020년도 추계학술대회
• /
• pp.252-255
• /
• 2020

Unsupervised deep learning methods have shown impressive results for the challenging monocular depth estimation task, a field of study that has gained attention in recent years. A common approach for this task is to train a deep convolutional neural network (DCNN) via an image synthesis sub-task, where additional views are utilized during training to minimize a photometric reconstruction error. Previous unsupervised depth estimation networks are trained within a fixed depth estimation range, irrespective of its possible range for a given image, leading to suboptimal estimates. To overcome this suboptimal limitation, we first propose an unsupervised adaptive depth estimation method guided by minimum and maximum (min-max) depth priors for a given input image. The incorporation of min-max depth priors can drastically reduce the depth estimation complexity and produce depth estimates with higher accuracy. Moreover, we propose a novel network architecture for adaptive depth estimation, called the AdaMM-DepthNet, which adopts the min-max depth estimation in its front side. Intensive experimental results demonstrate that the adaptive depth estimation can significantly boost up the accuracy with a fewer number of parameters over the conventional approaches with a fixed minimum and maximum depth range.

• Journal of Astronomy and Space Sciences
• /
• 제29권1호
• /
• pp.1-10
• /
• 2012

In this study, global positioning system (GPS)-derived precipitable water vapor (PWV) and microwave radiometer (MWR)-measured integrated water vapor (IWV) were compared and their characteristics were analyzed. Comparing those two quantities for two years from August 2009, we found that GPS PWV estimates were larger than MWR IWV. The average difference over the entire test period was 1.1 mm and the standard deviation was 1.2 mm. When the discrepancies between GPS PWV and MWR IWV were analyzed depending on season, the average difference was 0.7 mm and 1.9 mm in the winter and summer months, respectively. Thus, the average difference was about 2.5 times larger in summer than that in winter. However, MWR IWV measurements in the winter months were over-estimated than those in the summer months as the water vapor content got larger. The results of the diurnal analysis showed that MWR IWV was underestimated in the daytime, showing a difference of 0.8 mm. In the early morning hours, MWR IWV has a tendency to be over-estimated, with a difference of 1.3 mm with respect to GPS PWV.

• Asian-Australasian Journal of Animal Sciences
• /
• 제15권4호
• /
• pp.591-595
• /
• 2002

Three hundred thirty five progeny testing steers of Korean beef cattle were evaluated ultrasonically for back fat thickness (BFT), longissimus muscle area (LMA) and intramuscular fat (IF) before slaughter. Class measurements associated with the Korean yield grade and quality grade were also obtained. Residual standard deviation between ultrasonic estimates and carcass measurements of BFT, LMA were 1.49 mm and $0.96cm^2$. The linear correlation coefficients (p<0.01) between ultrasonic estimates and carcass measurements of BFT, LMA and IF were 0.75, 0.57 and 0.67, respectively. Results for improving predictions of yield grade by four methods-the Korean yield grade index equation, fat depth alone, regression and decision tree methods were 75.4%, 79.6%, 64.3% and 81.4%, respectively. We conclude that the decision tree method can easily predict yield grade and is also useful for increasing prediction accuracy rate.

• 방송공학회논문지
• /
• 제24권2호
• /
• pp.281-291
• /
• 2019

3D 카메라 기술 중에서 초점의 흐려짐을 이용한 깊이 추정은 카메라의 초점거리 평면의 물체는 선명한 상이 맺히지만 카메라의 초점거리 평면으로부터 멀어진 물체는 흐린 영상을 만들어낸다는 현상을 이용해 3D 깊이를 추정한다. 본 논문에서는 단일 카메라를 이용하여 촬영한 영상의 흐림 정도를 분석하여 3D 깊이를 추정하는 알고리즘을 연구하였다. 단일 카메라의 1 개의 영상 또는 단일 카메라의 초점이 서로 다른 2 개의 영상을 사용하여 초점의 흐려짐을 이용한 3D 깊이를 추정하는 방법을 통해 최적화된 피사체 범위를 도출하였다. 1 개의 영상을 이용한 깊이 추정에서는 스마트폰 카메라와 DSLR 카메라 모두 250 mm의 초점거리를 사용하는 것이 가장 좋은 성능을 보였다. 2개의 영상을 이용한 깊이 추정에서는 스마트폰 카메라 영상은 150 mm와 250 mm로 그리고 DSLR 카메라 영상은 200 mm와 300 mm로 초점거리를 설정하였을 때 가장 좋은 3D 깊이 추정 유효 범위를 갖는 것으로 나타났다.

• Asian-Australasian Journal of Animal Sciences
• /
• 제27권2호
• /
• pp.155-160
• /
• 2014

The purpose of this study was to estimate genetic parameters of ultrasound measurements for longissimus dorsi muscle area (LMA), backfat thickness (BFT), and marbling score (MS) in Hanwoo cows (N = 3,062) at the ages between 18 and 42 months. Data were collected from 100 Hanwoo breeding farms in Gyeongbuk province, Korea, in 2007 and 2008. The cows were classified into four different age groups, i.e. 18 to 22 months (the first pregnancy period), 23 to 27 (the first parturition), 28 to 32 (the second pregnancy), and 33 to 42 (the second parturition), respectively. For each age group, a multi-trait animal model was used to estimate variance components and heritabilities of the three traits. The averages of LMA, BFT, and MS measurements across the cows of all age groups were 50.1 $cm^2$, 4.62 mm, and 3.04, respectively and heritability estimates were 0.09, 0.10, and 0.08 for the respective traits. However, when the data were analyzed in different age groups, heritability estimates of LMA and BFT were 0.24 and 0.47, respectively, for the cows of 18 to 22 months of age, and 0.21 for MS in the 28 to 32 months old cows. When the cows of all age groups were used, the estimates of genetic (phenotypic) correlations were 0.43 (0.35), -0.06 (0.34) and 0.21 (0.32) between LMA and BFT, LMA and MS, and BFT and MS, respectively. However, in the cow age group between 28 and 32 (18 and 22) months, the estimates of genetic (phenotypic) correlations were 0.05 (0.29), -0.15 (0.24) and 0.38 (0.24), for the respective pairs of traits. These results suggest that genetic, environmental, and phenotypic variations differ depending on cow age, such that care must be taken when ultrasound measurements are applied to selection of cows for meat quality.

• 응용통계연구
• /
• 제29권5호
• /
• pp.787-806
• /
• 2016

사회환경 변화와 정보기술 발전에 따라 한 조사에 다양한 조사모드(survey mode)를 활용하는 혼합조사(mixed-mode survey)가 확대되고 있으며, 포함오차 축소, 비용절감, 응답률 향상 등의 장점을 가진다. 그러나 혼합조사는 선택효과와 측정효과가 혼재된 모드효과 발생으로 조사품질에 대한 우려가 있다. 통계개발원은 이러한 혼합조사의 모드효과를 파악하기 위하여 2014년에 병행적 혼합모드 시험조사를 수행하였다. 본 연구는 시험조사 자료에 대해 자기기입식 종이조사와 웹조사 간 모드효과를 선택효과와 측정효과로 분리하여 계량적으로 분석하였다. 선택계층의 효과를 분리하였을 때, 조사항목에 따라 과대 또는 과소 응답하는 측정효과가 존재하는 것을 확인하였다.

• Geomechanics and Engineering
• /
• 제35권4호
• /
• pp.411-424
• /
• 2023

Reasonable estimates of tunnel lining dislocations in the operation stage, especially under longitudinal differential settlement, are important for the design of waterproof gaskets. In this paper, a modified shell-joint model is proposed to calculate shield tunnel dislocations under longitudinal differential settlement, with the ability to consider the nonlinear shear stiffness of the joint. In the case of shell elements in the model, an elastoplastic damage constitutive model was adopted to describe the nonlinear stress-strain relationship of concrete. After verifying its applicability and correctness against a full-scale tunnel test and a joint shear test, the proposed model was used to analyze the dislocation behaviors of a shield tunnel in Shanghai Metro Line 2 under longitudinal differential settlement. Based on the results, when the tunnel structure is solely subjected to water-earth load, circumferential and longitudinal joint dislocations are all less than 0.1 mm. When the tunnel suffers longitudinal differential settlement and the curvature radius of the differential settlement is less than 300 m, although maximum longitudinal joint dislocation is still less than 0.1 mm, the maximum circumferential joint dislocation is approximately 10.3 mm, which leads to leakage and damage of the tunnel structure. However, with concavo-convex tenons applied to circumferential joints, the maximum dislocation value reduces to 4.5 mm.