• Title/Summary/Keyword: Predictive ability

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Quantitative structure activity relationship (QSAR) between chlorinated alkene ELUMO and their chlorine

  • Tang, Walter Z.;Wang, Fang
    • Advances in environmental research
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    • v.1 no.4
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    • pp.257-276
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    • 2012
  • QSAR models for chlorinated alkenes were developed between $E_{HOMO}$ and their chlorine and carbon content. The aim is to provide valid QSAR model which is statistically validated for $E_{LUMO}$ prediction. Different molecular descriptors, $N_{Cl}$, $N_C$ and $E_{HOMO}$ have been used to take into account relevant information provided by molecular features and physicochemical properties. The best model were selected using Partial Least Square (PLS) and Multiple Linear Regression (MLR) led to models with satisfactory predictive ability for a data set of 15 chlorinated alkene compounds.

The Variables Affecting Acculturative Stress of Women in International Marriages (국제결혼 이주여성의 문화적응스트레스와 관련요인에 대한 연구)

  • Lee, Jin-Suk
    • Korean Journal of Human Ecology
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    • v.19 no.6
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    • pp.919-932
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    • 2010
  • This investigation examined the association between demographic variables, acculturation and acculturative stress. Participants in the study were 360 Pilipino, Vietnamese, Chinese, Chinese-Korean and Japanese woman who had married internationally and were living in Jeonbuk-Do. Hierarchical regression analyses determined that among the independent variables examined, age, Korean language ability, marital satisfaction, and ethnic identity had significant predictive effects on the levels of acculturative stress experienced. Young women who had lower Korean language proficiency, lower marital satisfaction, and higher ethnic identity showed more higher level of acculturative stress. Implications of this research were discussed with particular attention given to possible support programs for women in international marriages.

3D-QSAR Studies of 8-Substituted-2-aryl-5-alkylaminoquinolines as Corticotropin-releasing Factor-1 Receptor Antagonists

  • Nagarajan, Santhosh Kumar;Madhavan, Thirumurthy
    • Journal of Integrative Natural Science
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    • v.8 no.3
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    • pp.176-183
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    • 2015
  • Corticotropin-releasing actor receptors (CRFRs) activates the hypothalamic pituitary adrenal axis, one of the 2 parts of the fight or flight response to stress. Increased CRH production has is associated with Alzheimer's disease and major depression and hypoglycemia. In this study, we report the important structural and chemical parameters for CRFR inhibitors using the derivatives of 8-substituted-2-aryl-5-alkylaminoquinolines. A 3D QSAR study, Comparative molecular field analysis (CoMFA) was performed. The best predictions were obtained for the best CoMFA model with a $q^2$ of 0.607 with 6 components and $r^2$ of 0.991. The statistical parameters from the generated CoMFA models indicated that the data are well fitted and have high predictive ability. The contour map resulted from the CoMFA models might be helpful in the future designing of novel and more potent CRFR derivatives.

3D-QSAR Studies of 3,5-disubstituted Quinolines Inhibitors of c-Jun N-terminal Kinase-3

  • Madhavan, Thirumurthy
    • Journal of Integrative Natural Science
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    • v.4 no.3
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    • pp.216-221
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    • 2011
  • c-Jun N-terminal kinase-3 (JNK-3) has been shown to mediate neuronal apoptosis and make the promising therapeutic target for neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, and other CNS disorders. In order to better understand the structural and chemical features of JNK-3, comparative molecular field analysis (CoMFA) was performed on a series of 3,5-disubstituted quinolines derivatives. The best predictions were obtained CoMFA model ($q^2$=0.707, $r^2$=0.972) and the statistical parameters from the generated 3D-QSAR models were indicated that the data are well fitted and have high predictive ability. The resulting contour map from 3D-QSAR models might be helpful to design novel and more potent JNK3 derivatives.

An Application of Dynamic Route Choice Model Using Optimal Control Theory (최적제어이론을 이용한 동적 통행배정 모형의 적용에 관한 연구)

  • 전경수;오세현
    • Journal of Korean Society of Transportation
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    • v.13 no.4
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    • pp.5-29
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    • 1995
  • Advanced Traveler Inoformation Systems*ATIS) , as a subsystem of ITS influence the travel choices of dreivers by providing them with historical, real-time and predictive information to supprot travel decisions and consequently improves the speed and quality of travel. For thesuccessul accomplishment of ATIS, the time-dependent variations of traffic in a road network and travel times of vehicles during their journey must be predicted . The purpose of this study is to evaluate the past developments in the dynamic route choice models and to apply the instantaneous dynamic user optimal route choice model. recently formulated with flow propagation constraints by Ran, Boyce and LeBlanc, to the real transportation network of Seocho-Ku in Seoul. As input data for this application, the time-dependent travel rates are estimated and the link travel time function is derived. The modelis validated from three view points : the efficiency of model itself the ability to predict traffic volume and travel time on links, and the optimal traffic control.

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A Plasma-Etching Process Modeling Via a Polynomial Neural Network

  • Kim, Dong-Won;Kim, Byung-Whan;Park, Gwi-Tae
    • ETRI Journal
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    • v.26 no.4
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    • pp.297-306
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    • 2004
  • A plasma is a collection of charged particles and on average is electrically neutral. In fabricating integrated circuits, plasma etching is a key means to transfer a photoresist pattern into an underlayer material. To construct a predictive model of plasma-etching processes, a polynomial neural network (PNN) is applied. This process was characterized by a full factorial experiment, and two attributes modeled are its etch rate and DC bias. According to the number of input variables and type of polynomials to each node, the prediction performance of the PNN was optimized. The various performances of the PNN in diverse environments were compared to three types of statistical regression models and the adaptive network fuzzy inference system (ANFIS). As the demonstrated high-prediction ability in the simulation results shows, the PNN is efficient and much more accurate from the point of view of approximation and prediction abilities.

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Combining Ridge Regression and Latent Variable Regression

  • Kim, Jong-Duk
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.1
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    • pp.51-61
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    • 2007
  • Ridge regression (RR), principal component regression (PCR) and partial least squares regression (PLS) are among popular regression methods for collinear data. While RR adds a small quantity called ridge constant to the diagonal of X'X to stabilize the matrix inversion and regression coefficients, PCR and PLS use latent variables derived from original variables to circumvent the collinearity problem. One problem of PCR and PLS is that they are very sensitive to overfitting. A new regression method is presented by combining RR and PCR and PLS, respectively, in a unified manner. It is intended to provide better predictive ability and improved stability for regression models. A real-world data from NIR spectroscopy is used to investigate the performance of the newly developed regression method.

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Design of Hybrid Architecture of Neurofuzzy Polynomial Networks (뉴로퍼지 다항식 네트워크의 하이브리드 구조 설계)

  • Park, Byoung-Jun;Park, Ho-Sung;Oh, Sung-Kwun;Jang, Sung-Whan
    • Proceedings of the KIEE Conference
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    • 2001.11c
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    • pp.424-427
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    • 2001
  • In this study, we introduce a concept of neurofuzzy polynomial networks (NFPN), a hybrid modeling architecture combining neurofuzzy networks (NFN) and polynomial neural networks(PNN). NFN contributes to the formation of the premise part of the rule-based structure of the NFPN. The consequence part of the NFPN is designed using PNN. The parameters of the membership functions, learning rates and momentum coefficients are adjusted with the use of genetic optimization. We introduce two kinds of NFPN architectures, namely the basic and the modified one. Owing to the specific features of two combined architectures, it is possible to consider the nonlinear characteristics of process system and to obtain the better output performance with superb predictive ability.

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Crown Ratio Models for Tectona grandis (Linn. f) Stands in Osho Forest Reserve, Oyo State, Nigeria

  • Popoola, F.S.;Adesoye, P.O.
    • Journal of Forest and Environmental Science
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    • v.28 no.2
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    • pp.63-67
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    • 2012
  • Crown ratio is the ratio of live crown length to tree height. It is often used as an important predictor variable for tree growth equation. It indicates tree vigor and is a useful parameter in forest health assessment. The objective of the study was to develop crown ratio prediction models for Tectona grandis. Based on the data set from the temporary sample plots, several non linear equations including logistics, Chapman Richard and exponential functions were tested. These functions were evaluated in terms of coefficient of determination ($R^2$) and standard error of the estimate (SEE). The significance of the estimated parameters was also verified. Plot of residuals against estimated crown ratios were observed. Although the logistic model had the highest $R^2$ and the least SEE, Chapman-Richard and Exponential functions were observed to be more consistent in their predictive ability; and were therefore recommended for predicting crown ratio in the stand.

Model-based iterative learning control with quadratic criterion for linear batch processes (선형 회분식 공정을 위한 이차 성능 지수에 의한 모델 기반 반복 학습 제어)

  • Lee, Kwang-Soon;Kim, Won-Cheol;Lee, Jay-H
    • Journal of Institute of Control, Robotics and Systems
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    • v.2 no.3
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    • pp.148-157
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    • 1996
  • Availability of input trajectories corresponding to desired output trajectories is often important in designing control systems for batch and other transient processes. In this paper, we propose a predictive control-type model-based iterative learning algorithm which is applicable to finding the nominal input trajectories of a linear time-invariant batch process. Unlike the other existing learning control algorithms, the proposed algorithm can be applied to nonsquare systems and has an ability to adjust noise sensitivity as well as convergence rate. A simple model identification technique with which performance of the proposed learning algorithm can be significantly enhanced is also proposed. Performance of the proposed learning algorithm is demonstrated through numerical simulations.

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