• 대한조선학회논문집
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• 제52권1호
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• pp.1-7
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• 2015

The weight estimation of floating offshore structures such as FPSO, TLP, semi-Submersibles, Floating Offshore Wind Turbines etc. in the preliminary design, is one of direct measures of both construction cost and basic performance. Through both literature investigation and internet search, the weight data of floating offshore structures such as FPSO and TLP was collected. In this study, the weight estimation model with the genetic programming was suggested for FPSO. The weight estimation model using genetic programming was established by fixing the independent variables based on this data. In addition, the correlation analysis was performed to make up for the weak points of genetic programming; it is apt to induce over-fitting when the number of data is relatively smaller than that of independent variables. That is, by reducing the number of variables through the analysis of the correlation between the independent variables, the increasing effect in the number of weight data can be expected. The reliability of the developed weight estimation model was within 2% of error rate.

• 한국농공학회논문집
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• 제59권1호
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• pp.11-20
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• 2017

This study is to estimate the spatial soil moisture using multiple linear regression model (MLRM) and 15 minutes interval Land Surface Temperature (LST) data of Communication, Ocean and Meteorological Satellite (COMS). For the modeling, the input data of COMS LST, Terra MODIS Normalized Difference Vegetation Index (NDVI), daily rainfall and sunshine hour were considered and prepared. Using the observed soil moisture data at 9 stations of Automated Agriculture Observing System (AAOS) from January 2013 to May 2015, the MLRMs were developed by twelve scenarios of input components combination. The model results showed that the correlation between observed and modelled soil moisture increased when using antecedent rainfalls before the soil moisture simulation day. In addition, the correlation increased more when the model coefficients were evaluated by seasonal base. This was from the reverse correlation between MODIS NDVI and soil moisture in spring and autumn season.

• 대한건축학회연합논문집
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• 제21권3호
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• pp.11-21
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• 2019

The purpose of this study was to present an analysis model for finding the correlation between visibility and evacuation time as users move in the outpatient department of the general hospital. The spatial scope of the study was limited to the first floor and second floor which are used for the outpatient department. Traffic density in outpatient departments was surveyed on site. Based on the surveyed traffic density, the evacuation simulation model was established for calculating the escape route and evacuation time for an individual user. The traffic density of the outpatient department as per the evacuation time was also calculated. With using evacuation simulations, the flow of evacuees was calculated through the density of traffic over the time of evacuation. Visibility data were set in the simulation model for users' escape routes. A correlation analysis between the product of evacuation flow measure and visibility measure of the evacuation population and evacuation time was performed. The analysis result showed negative correlation within a specific distance range. This study presented an analysis model showing that the evacuation condition considering spatial visibility in the outpatient department of general hospital visibility was negatively related to the analyzed evacuation time at the design stage.

• Structural Engineering and Mechanics
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• 제11권3호
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• pp.259-272
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• 2001

The impact behavior of a multigirder concrete bridge under single and multiple moving vehicles is studied based on correlated road surface characteristics. The bridge structure is modeled as grillage beam system. A 3D nonlinear vehicle model with eleven degrees of freedom is utilized according to the HS20-44 truck design loading in the American Association of State Highway and Transportation Officials (AASHTO) specifications. A triangle correlation model is introduced to generate four classes of longitudinal road surface roughness as multi-correlated random processes along deck transverse direction. On the basis of a correlation length of approximately half the bridge width, the upper limits of impact factors obtained under confidence level of 95 percent and side-by-side three-truck loading provide probability-based evidence for the evaluation of AASHTO specifications. The analytical results indicate that a better transverse correlation among road surface roughness generally leads to slightly higher impact factors. Suggestions are made for the routine maintenance of this type of highway bridges.

• 대한기계학회논문집A
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• 제30권7호
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• pp.787-793
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• 2006

Recently kriging model has been widely used in the DACE (Design and Analysis of Computer Experiment) because of prominent predictability of nonlinear response. Since DACE has no random or measurement errors contrast to physical experiment, space filling experimental design that distributes uniformly design points over whole design space should be employed as a sampling method. In this paper, we examine the maximum entropy experimental design that reveals the space filling strategy in which defines the maximum entropy based on Gaussian or exponential. The influence of these two correlation functions on space filling design and their model parameters are investigated. Based on the exploration of numerous numerical tests, enhanced maximum entropy design based on exponential correlation function is suggested.

• 한국항해항만학회지
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• 제40권2호
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• pp.51-56
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• 2016

Expressways mean the primary arterial highways with a high level of efficiency and safety. However, Gyeongbu and Namhae expressways connected with Busan ports are showing travel time delay by increased traffic including the medium/large-sized vehicles of about 20% compared to those of about 13% regardless of the peak periods. This study, thus, intends to analyze lane traffic characteristics in the basic 8-lane segments of the above-mentioned expressways, compute the planning and buffer times based on travel time reliability, find the lane speed showing a higher correlation with planning time between the lane speeds in the basic 8-lane segments, and finally suggest a correlation model for predicting the planning time in expressways.

• Korean Chemical Engineering Research
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• 제53권6호
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• pp.814-817
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• 2015

A new ionic mass transfer correlation is derived for the fluid-saturated, horizontal porous layer. Darcy-Forchheimer model is used to explain characteristics of fluid motion. Based on the microscales of turbulence a backbone mass transfer relation is derived as a function of the Darcy-Rayleigh number, $Ra_D$ and the porous medium Schmidt number, $Sc_p$. For the Darcy's limit of $Sc_p{\gg}Ra_D$, the Sherwood number, Sh is a function of $Ra_D$ only. However, for the region of high $Ra_D$, Sh can be related with $Ra_DSc_p$. Based on the present backbone equation and the electrochemical mass transfer experiments which are electro plating or electroless plating, the new ionic mass transfer correlation is suggested in the porous media.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2006년도 한국컴퓨터종합학술대회 논문집 Vol.33 No.1 (B)
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• pp.352-354
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• 2006

패턴완성(Pattern Completion)은 사용되는 패턴 성분들 사이의 higher-order correlation 정보가 중요한 의미를 가질 수 있는 기계학습 문제 중 하나이다. higher-order correlation은 확률라이브러리모델(Probabilistic Library Model)로 구현되는 hypernetwork 개념을 도입해서 나타낼 수 있다. 하지만 확률라이브러리모델을 사용하여 higher-order 정보를 나타내려할 때 초기라이브러리가 모든 가능한 조합의 원소들을 가지도록 구성하기는 쉽지 않다. 그 대안으로 초기라이브러리 구성 시 학습패턴들을 subsampling하여 적은 숫자의 원소들만으로 higher-order correlation의 근사치를 나타내게 할 수 있다. 본 논문에서는 이와 같이 subsampling이 사용되어 구성된 확률라이브러리모델을 이용한 패턴완성시의 correlation의 order에 따른 효과를 분석하여 본다.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2007년도 추계종합학술대회
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• pp.328-331
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• 2007

본 논문은 Correlated MIMO-OFDM 페이딩 채널을 위한 클러스터 응답 모델의 용량에 대한 연구이다. 송신기에서 채널 정보를 알고 있는 경우와 채널 정보를 모르는 경우를 고려하여, 수신기의 correlation에 의한 용량과 송${\cdot}$수신기 양쪽의 correlation에 의한 용량을 비교 한다. 결과로부터 수신기의 correlation에 의한 용량이 송${\cdot}$수신기의 correlation에 의한 용량보다 더 좋은 것을 확인 할 수 있다. 또한 Water-filling 방법을 사용하여 송신 안테나에 파워를 할당한 경우 균일한 파워를 할당한 경우보다 Water-filling 이득에 의해 더 큰 용량을 가지는 것으로 나타난다. 그러나 클러스터의 수가 correlation 행렬의 최대 랭크보다 크고 SNR이 높은 영역인 경우 Water-filling에 의한 이득이 거의 없음을 보인다.

• Asian-Australasian Journal of Animal Sciences
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• 제15권8호
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• pp.1085-1090
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• 2002

Genetic parameters for birth weights (BWT), calving ease scores observed from calves born by heifers (CEH), and calving ease scores observed from calves born by cows (CEC) were estimated using Bayesian methodology with Gibbs sampling in different threshold animal models. Data consisted of 77,458 records for calving ease scores and birth weights in Gelbvieh cattle. Gibbs samplers were used to obtain the parameters of interest for the categorical traits in two univariate threshold animal models, a bivariate threshold animal model, and a three-trait linear-threshold animal model. Samples of heritabilities and genetic correlations were calculated from the posterior means of dispersion parameters. In a univariate threshold animal model with CEH (model 1), the posterior means of heritabilities for calving ease was 0.35 for direct genetic effects and 0.18 for maternal genetic effects. In the other univariate threshold model with CEC (model 2), the posterior means of heritabilities of CEC was 0.28 for direct genetic effects and 0.18 for maternal genetic effects. In a bivariate threshold model with CEH and CEC (model 3), heritability estimates were similar to those in unvariate threshold models. In this model, genetic correlation between heifer calving ease and cow calving ease was 0.89 and 0.87 for direct genetic effect and maternal genetic effects, respectively. In a three-trait animal model, which contained two categorical traits (CEH and CEC) and one continuous trait (BWT) (model 4), heritability estimates of CEH and CEC for direct (maternal) genetic effects were 0.40 (0.23) and 0.23 (0.13), respectively. In this model, genetic correlation estimates between CEH and CEC were 0.89 and 0.66 for direct genetic effects and maternal effects, respectively. These estimates were greater than estimates between BWT and CEH (0.82 and 0.34) or BWT and CEC (0.85 and 0.26). This result indicates that CEH and CEC should be high correlated rather than estimates between calving ease and birth weight. Genetic correlation estimates between direct genetic effects and maternal effects were -0.29, -0.31 and 0.15 for BWT, CEH and CEC, respectively. Correlation for permanent environmental effects between BWT and CEC was -0.83 in model 4. This study can provide genetic evaluation for calving ease with other continuous traits jointly with assuming that calving ease from first calving was a same trait to calving ease from later parities calving. Further researches for reliability of dispersion parameters would be needed even if the more correlated traits would be concerned in the model, the higher reliability could be obtained, especially on threshold model with property that categorical traits have little information.