• Title/Summary/Keyword: Correlation model

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Analysis of Linear Regression Model with Two Way Correlated Errors

  • Ssong, Seuck-Heun
    • Journal of the Korean Statistical Society
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    • v.29 no.2
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    • pp.231-245
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    • 2000
  • This paper considers a linear regression model with space and time data in where the disturbances follow spatially correlated error components. We provide the best linear unbiased predictor for the one way error components. We provide the best linear unbiased predictor for the one way error component model with spatial autocorrelation. Further, we derive two diagnostic test statistics for the assessment of model specification due to spatial dependence and random effects as an application of the Lagrange Multiplier principle.

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Study of Design Flood Estimation by Watershed Characteristics (유역특성인자를 이용한 설계홍수량 추정에 관한 연구)

  • Park, Ki-Bum
    • Journal of Environmental Science International
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    • v.15 no.9
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    • pp.887-895
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    • 2006
  • Through this research of the analysis on the frequency flood discharges regarding basin property factors, a linear regression system was introduced, and as a result, the item with the highest correlation with the frequency flood discharges from Nakdong river basin is the basin area, and the second highest is the average width of basin and the river length. The following results were obtained after looking at the multi correlation between the flood discharge and the collected basin property factors using the data from the established river maintenance master plan of the one hundred twenty-five rivers in the Nakdong river basin. The result of analysis on multivariate correlation between the flood discharges and the most basic data in determining the flood discharges as basin area, river length, basin slope, river slope, average width of basin, shape factor and probability precipitation showed more than 0.9 of correlation in terms of the multi correlation coefficient and more than 0.85 for the determination coefficient. The model which induced a regression system through multi correlation analysis using basin property factors is concluded to be a good reference in estimating the design flood discharge of unmeasured basin.

A novel time scale of dynamic heterogeneity in a supercooled liquid system

  • Mun, Seok-Jin;Park, Gye-Hyeon;Park, Sang-Won;Jeong, Yeon-Jun
    • Proceeding of EDISON Challenge
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    • 2015.03a
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    • pp.138-146
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    • 2015
  • 액체 상태의 물질이 매우 급속하게 냉각되면 일반적으로 과냉각액체(supercooled liquid) 상태에 도달한다. 과냉각액체는 더 낮은 온도에서 유리상(glass phase)으로 상전이를 일으킨다고 알려져 있는데, 이때 나타나는 동역학적 불균일성(dynamic heterogeneity)은 상전이를 기술하는데 중요한 역할을 한다. 그러나 일반적인 액체의 상전이를 연구할 때 주로 사용되던 상관함수(correlation function)으로는 이러한 불균일성을 정량적으로 표현하기 어렵기 때문에 동역학적 민감도(dynamic susceptibility)나 multi-time correlation function 등 동역학적 성질(dynamic property)로부터 특징적인 시간 개념 및 거리 개념을 도출하려는 연구가 많이 진행되어 왔다. 본 논문에서는 일반적으로 특징적인 거리 개념을 도출해 내는데 사용되는 4점 밀도 상관함수(four-point density correlation function)인 dynamic susceptibility(${\chi}^4$)가 입자 밀도의 요동(fluctuation)의 상관관계(correlation)가 지속되는 특징적인 시간 개념에 대한 정보 또한 포함하고 있다는 점에 주목하였다. 이에 따라 ${\chi}^4$의 시간에 대한 적분인 ${\tau}_4$를 새롭게 도입하였으며 그 결과로 ${\tau}_4$는 three-time density correlation function으로부터 도출한 ${\tau}_{Dh}$와 같은 축척(scaling)을 가지는 것을 확인하였다. 과냉각액체에 대한 장난감 모형(toy model)의 일종인 "Lennard-Jones potential 하에서 운동하는 서로 다른 두 종류의 입자들"을 연구에 사용하였다.

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The Correlation Factors on the Analysis of Demand Factors for Apartments (주택수요 예측인자 영향도 분석에 의한 상관인자선정)

  • Yang Seung-Won;Park Keun-Joon
    • Korean Journal of Construction Engineering and Management
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    • v.6 no.1 s.23
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    • pp.80-88
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    • 2005
  • This research describes an interactive process of analysing the demand factors for apartment on Cheonan area Using subjective statistical data for demand factor the process are categorized into main factors explained for the sensitiveness of correlation coefficient. This investigation is based on an analysis of the work of time series data One of the propose of this research is determining the correlation factors that can be effectively used in the model of forcasting. The results show a significant correlation coefficient on correlation matrix to iud the optimum correlation factors. The paper thus shows how to gain greater influntial factors on principal component analysis Consequently, this paper provides useful information about correlationship, but has limit of regional boundary for effectiveness.

Urokinase Inhibitor Design Based on Pharmacophore Model Derived from Diverse Classes of Inhibitors

  • Shui, Liu;Bharatham, Nagakumar;Bharatham, Kavitha;Lee, Keun-Woo
    • Bioinformatics and Biosystems
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    • v.1 no.2
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    • pp.115-122
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    • 2006
  • A three-dimensional pharmacophore model was developed based on 24 currently available inhibitors, which were rationally selected from 472 compounds with diverse molecular structure and bioactivity, for generating pharmacophore of uPA (Urokinase Plasminogen Activator) inhibitors. The best hypothesis (Hypo1) comprised of five features, namely, one positive ionizable group, one hydrogen-bond acceptor group and three hydrophobic aromatic groups. The correlation coefficient, root mean square deviation and cost difference were 0.973, 0.695, and 94.291 respectively, suggesting that a highly predictive pharmacophore model was successfully obtained. The application of the model showed great success in predicting the activities of 251 known uPA inhibitors (test set) with a correlation coefficient of 0.837, and there was also none of the outcome hypotheses that had similar cost difference and RMS deviation (RMSD) with that of the initial hypothesis generated by Cat-Scramble validation test with 95% confidence level. Accordingly, our model should be reliable in identifying structurally diverse compounds with desired biological activity.

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A Deep Learning-based Streetscapes Safety Score Prediction Model using Environmental Context from Big Data (빅데이터로부터 추출된 주변 환경 컨텍스트를 반영한 딥러닝 기반 거리 안전도 점수 예측 모델)

  • Lee, Gi-In;Kang, Hang-Bong
    • Journal of Korea Multimedia Society
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    • v.20 no.8
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    • pp.1282-1290
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    • 2017
  • Since the mitigation of fear of crime significantly enhances the consumptions in a city, studies focusing on urban safety analysis have received much attention as means of revitalizing the local economy. In addition, with the development of computer vision and machine learning technologies, efficient and automated analysis methods have been developed. Previous studies have used global features to predict the safety of cities, yet this method has limited ability in accurately predicting abstract information such as safety assessments. Therefore we used a Convolutional Context Neural Network (CCNN) that considered "context" as a decision criterion to accurately predict safety of cities. CCNN model is constructed by combining a stacked auto encoder with a fully connected network to find the context and use it in the CNN model to predict the score. We analyzed the RMSE and correlation of SVR, Alexnet, and Sharing models to compare with the performance of CCNN model. Our results indicate that our model has much better RMSE and Pearson/Spearman correlation coefficient.

HQSAR Study of Microsomal Prostaglandin E2 Synthase (mPGES-1) Inhibitors

  • San Juan, Amor A.;Cho, Seung-Joo;Cho, Hoon
    • Bulletin of the Korean Chemical Society
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    • v.27 no.10
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    • pp.1531-1536
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    • 2006
  • Microsomal prostaglandin $E_2$ synthase (mPGES-1) is an enzyme that is associated with inflammation, pain, fever and cancer. Hologram quantitative structure activity relationship (HQSAR) was conducted on the series of MK-886 compounds acting as mPGES-1 inhibitors. A training set with 24 compounds was used to establish the HQSAR model. The best model was chosen based on the cross-validated correlation coefficient ($q^2$=0.884) and the correlation coefficient($r^2$=0.976). The model was utilized to predict the activity of the eight-test set of compounds giving the predictive $r^2$ value of 0.845. The descriptors of the model are based on fragment distinction (atoms, bond and connectivity) and fragment size (2-5 atoms). The atomic contribution maps generated from HQSAR were useful in identifying the important structural features responsible for the inhibitory activity of MK-886 inhibitors. Based on the generated model, the presence of hydrophobic biphenyl group seems to enhance inhibition of mPGES-1 that is in agreement with the previous experiments. In addition, it seems important for a halogen to be substituted to the biphenyl ring and for an acyl group to be attached to the indole moiety for enhanced activity.

The Design of an Extended Complex Event Model for the Event Correlation Based Network Management Systems (이벤트 상관 기반의 네트워크 관리 시스템을 위한 복합 이벤트 모델의 설계)

  • Lee, Ki-Seong;Lee, Chang-Ha;Lee, Chan-Gun
    • Journal of KIISE:Information Networking
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    • v.37 no.1
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    • pp.8-15
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    • 2010
  • In this study, we present an extended complex event model by considering both of the complex event and the aspect-oriented programming. We propose an advanced scheme for the event specification suited for the event correlation based network management systems by merging these two models. Specifically, we extend the model to support hierarchical event structures and let the model recognize point-cuts of aspect-oriented programming as events. We provide the event operators designed to specify the events on instances and handle temporal relations of the instances. Lastly, we compare the proposed model with other event models and present the benefits of it.

Camera Calibration Using the Fuzzy Model (퍼지 모델을 이용한 카메라 보정에 관한 연구)

  • 박민기
    • Journal of the Korean Institute of Intelligent Systems
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    • v.11 no.5
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    • pp.413-418
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    • 2001
  • In this paper, we propose a new camera calibration method which is based on a fuzzy model instead of a physical camera model of the conventional method. The camera calibration is to determine the correlation between camera image coordinate and real world coordinate. The camera calibration method using a fuzzy model can not estimate camera physical parameters which can be obtained in the conventional methods. However, the proposed method is very simple and efficient because it can determine the correlation between camera image coordinate and real world coordinate without any restriction, which is the objective of camera calibration. With calibration points acquired out of experiments, 3-D real world coordinate and 2-D image coordinate are estimated using the fuzzy modeling method and the results of the experiments demonstrate the validity of the proposed method.

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ANALYSIS OF RAYLEIGH-BENARD NATURAL CONVECTION WITH THE SECOND-MOMENT TURBULENCE MODEL (이차모멘트 난류모델을 사용한 Rayleigh-Benard 자연대류 유동 해석)

  • Choi, Seok-Ki;Kim, Seong-O
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03a
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    • pp.111-117
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    • 2008
  • This paper reports briefly on the computational results of a turbulent Rayleigh-Benard convection with the elliptic-blending second-moment closure (EBM). The primary emphasis of the study is placed on an investigation of accuracy and numerical stability of the elliptic-blending second-moment closure for the turbulent Rayleigh-Benard convection. The turbulent heat fluxes in this study are treated by the algebraic flux model with the temperature variance and molecular dissipation rate of turbulent heat flux. The model is applied to the prediction of the turbulent Rayleigh-Benard convection for Rayleigh numbers ranging from $Ra=2{\times}10^6$ to $Ra=10^9$, and the computed results are compared with the previous experimental correlations, T-RANS and LES results. The predicted cell-averaged Nusselt number follows the correlation by Peng et al.(2006) ($Nu=0.162Ra^{0.286}$) in the 'soft' convective turbulence region ($2{\times}10^6{\leq}Ra{\leq}4{\times}10^7$) and it follows the experimental correlation by Niemela et al. (2000) ($Nu=0.124Ra^{0.309}$) in the 'hard' convective tubulence region ($10^8{\leq}Ra{\leq}10^9$) within 5% accuracy. This results show that the elliptic-blending second-moment closure with an algebraic flux model predicts very accurately the Rayleigh Benard convection.

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