• 제목/요약/키워드: predictive ability

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How Derivational Prefix Instruction Impacts Incidental Vocabulary Acquisition and Reading Comprehension

  • Choi, Sung-Mook
    • 영어어문교육
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    • 제13권3호
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    • pp.1-22
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    • 2007
  • The study examined the effects of explicit derivational morphology instruction (henceforth DMI) on the incidental vocabulary acquisition and reading comprehension of 132 Korean 1st-year high school students who responded to a battery of tests (two vocabulary tests and a reading comprehension test). Multiple statistical tools were used to analyze the data: Analysis of Covariance (ANCOVA), Analysis of Variance (ANOVA), Simple Regression Analysis, Tests of Simple Main Effects, and effect size computation using Cohen's d. The results indicated that (a) DMI enhanced students' ability to infer word meanings in context, (b) DMI promoted high proficiency students' reading comprehension, whereas it impeded intermediate proficiency students' reading comprehension, (c) vocabulary knowledge has a strong positive predictive value for reading comprehension, and (d) the gaps of vocabulary knowledge across proficiency levels were still substantial, despite the observation that DMI promoted students' vocabulary acquisition. These results have a bearing on English as Foreign Language (EFL) reading pedagogy.

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최적화에서의 근사모델 관리기법의 활용 (A Framework for Managing Approximation Models in place of Expensive Simulations in Optimization)

  • 양영순;장범선;연윤석
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 2000년도 봄 학술발표회논문집
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    • pp.159-167
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    • 2000
  • In optimization problems, computationally intensive or expensive simulations hinder the use of standard optimization techniques because the computational expense is too heavy to implement them at each iteration of the optimization algorithm. Therefore, those expensive simulations are often replaced with approximation models which can be evaluated nearly free. However, because of the limited accuracy of the approximation models, it is practically impossible to find an exact optimal point of the original problem. Significant efforts have been made to overcome this problem. The approximation models are sequentially updated during the iterative optimization process such that interesting design points are included. The interesting points have a strong influence on making the approximation model capture an overall trend of the original function or improving the accuracy of the approximation in the vicinity of a minimizer. They are successively determined at each iteration by utilizing the predictive ability of the approximation model. This paper will focuses on those approaches and introduces various approximation methods.

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회전기계의 이상진동진단 시스템의 개발 (Development of Vibration Diagnosis System for Rotating Machine)

  • 양보석;장우교;김호종
    • 소음진동
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    • 제6권3호
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    • pp.325-332
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    • 1996
  • One of the greatest shortcoming in today's predictive maintenance program is the ability to diagnose the mechanical and electrical problems within the machine when the vibration exceeds preset overall and spectral alarm levels. In this study, auto-diagnosis system is constructed by using A/D converter to convert analog to digital singal. With this device the system analyses input signal to diagonosis machine condition. Many plots, which display machine condition, and input values of every channel are calculated in this system. If the falut is found, the system diagnoses automatically using fuzzy algorithm and trend monitoring. Prediction is also performed by the grey system theory. Operator finds out eh machine operating condition intuitively based on with personal computer CRT in using this system.

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Quantitative Structure-Activity Relationships for Radical Scavenging Activities of Flavonoid Compounds by GA-MLR Technique

  • Om, Ae-Son;Ryu, Jae-Chun;Kim, Jae-Hyoun
    • Molecular & Cellular Toxicology
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    • 제4권2호
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    • pp.170-176
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    • 2008
  • The quantitative structure-activity relationship (QSAR) of a set of 35 flavonoid compounds presenting antioxidant activity was established by means of Genetic Algorithm-Multiple Linear Regression (GA-MLR) technique. Four-parametric models for two sets of data, the 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging activity $(R^2=0.788,\;Q^2_{cv}=0.699\;and\;Q^2_{ext}=0.577)$ and scavenging activity of reactive oxgen species (ROS) induced by $H_2O_2 (R^=0.829,\;Q^2_{cv}=0.754\;and\;Q^2_{ext}=0.573)$ were obtained with low external predictive ability on a mass basis, respectively. Each model gave some different mechanistic aspects of the flavonoid compounds tested in terms of the radical scavenging activity. Topological charge, H-bonding complex and deprotonation processes were likely to be involved in the radical scavenging activity.

이산사건 시뮬레이션을 이용한 공간구조론의 검증 및 평가 (Verification and Evaluation of Spatial Structure Theory through Discrete Event Simulation)

  • 윤소희;김석태
    • 한국멀티미디어학회논문지
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    • 제19권12호
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    • pp.2000-2013
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    • 2016
  • The purpose of this study is to validate the validity of the methodology for analyzing the space with complex characteristics and to evaluate the existing spatial structure analysis theory. Seven example models are designed and analyzed data of spatial syntax analysis and visibility graph analysis. And analyzed the agent-based model using two analytical methods: the adjacent space and the whole spatial connection. The results of this study are as follows. Based on the analysis of the agent - based model for perfectly freewalking, the validity of the method is verified in terms of predictive ability and effectiveness. Agent-based models can be simulated considering various variables, so realistic predictions will be possible and a new biography of complex systems can be met.

차분 진화 알고리즘 기반 방사형 기저 함수 신경회로망 분류기의 최적화 방법 (Optimization Method of Differential Evolution-based Radial Basis Function Neural Networks)

  • 마창민;오성권
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1962-1963
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    • 2011
  • 본 연구에서는 패턴분류를 위해 최적화된 방사형 기저 함수 신경회로망(Radial Basis Function Neural Networks) 분류기를 제안한다. RBFNN은 입력층, 은닉층, 출력층의 3층 구조로 되어 있으며 Multi Dimension, Predictive ability, Robustness한 특징이 있다. RBFNN의 은닉층에는 기존의 활성함수가 아닌 Fuzzy C-means 클러스터링 알고리즘을 사용하여 입력 데이터의 특성을 고려한 적합도를 사용하였다. RBFNN은 은닉층의 노드수와 FCM 클러스터링의 퍼지화 계수, 연결가중치의 다항식 타입이 모델의 성능의 향상에 영향을 미치기 때문에 최적화가 필요하며 본 논문에서는 Differential Evolution(DE) 알고리즘을 사용하여 모델의 구조 및 파라미터를 최적화시켜 모델의 성능을 향상시켰다. 제안된 모델을 평가하기 위해 패턴분류에 많이 사용되는 Iris 데이터와 Wine 데이터를 이용하였다.

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마할라노비스-다구치 시스템과 로지스틱 회귀의 성능비교 : 사례연구 (Performance Comparison of Mahalanobis-Taguchi System and Logistic Regression : A Case Study)

  • 이승훈;임근
    • 대한산업공학회지
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    • 제39권5호
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    • pp.393-402
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    • 2013
  • The Mahalanobis-Taguchi System (MTS) is a diagnostic and predictive method for multivariate data. In the MTS, the Mahalanobis space (MS) of reference group is obtained using the standardized variables of normal data. The Mahalanobis space can be used for multi-class classification. Once this MS is established, the useful set of variables is identified to assist in the model analysis or diagnosis using orthogonal arrays and signal-to-noise ratios. And other several techniques have already been used for classification, such as linear discriminant analysis and logistic regression, decision trees, neural networks, etc. The goal of this case study is to compare the ability of the Mahalanobis-Taguchi System and logistic regression using a data set.

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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    • 제1권4호
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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.

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

  • 이진숙
    • 한국생활과학회지
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    • 제19권6호
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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
    • 통합자연과학논문집
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    • 제8권3호
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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.