• Title/Summary/Keyword: logistic function

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Classification via principal differential analysis

  • Jang, Eunseong;Lim, Yaeji
    • Communications for Statistical Applications and Methods
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    • v.28 no.2
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    • pp.135-150
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    • 2021
  • We propose principal differential analysis based classification methods. Computations of squared multiple correlation function (RSQ) and principal differential analysis (PDA) scores are reviewed; in addition, we combine principal differential analysis results with the logistic regression for binary classification. In the numerical study, we compare the principal differential analysis based classification methods with functional principal component analysis based classification. Various scenarios are considered in a simulation study, and principal differential analysis based classification methods classify the functional data well. Gene expression data is considered for real data analysis. We observe that the PDA score based method also performs well.

Optical encryption of multiple images using amplitude mask and 2D chaos function (진폭 마스크와 2D 카오스 함수를 이용한 다중 이미지 광학 암호화)

  • Kim, Hwal;Jeon, Sungbin;Kim, Do-Hyung;Park, No-Cheol;Park, Young-Pil
    • Transactions of the Society of Information Storage Systems
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    • v.10 no.2
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    • pp.50-54
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    • 2014
  • Object image using DRPE(Double Random Phase Encryption) in 4f system is encrypted by space-division method using amplitude mask. However, this method has the weakness for the case of having partial data of amplitude mask which can access the original image. To improve the security, we propose the method using the 2-dimension logistic chaos function which shuffles the encrypted data. It is shown in simulation results that the proposed method is highly sensitive to chaos function parameters. To properly decrypt from shuffled encryption data, below 1e-5 % errors of each parameter should be required. Thus compared with conventional method the proposed shows the higher security level.

A Statistical Mobilization Criterion for Debris-flow (통계 분석을 통한 산사태 토석류 전이규준 모델)

  • Yoon, Seok;Lee, Seung-Rae;Kang, Sin-Hang;Park, Do-Won
    • Journal of the Korean Geotechnical Society
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    • v.31 no.6
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    • pp.59-69
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    • 2015
  • Recently, landslide and debris-flow disasters caused by severe rain storms have frequently occurred. Many researches related to landslide susceptibility analysis and debris-flow hazard analysis have been conducted, but there are not many researches related to mobilization analysis for landslides transforming into debris-flow in slope areas. In this study, statistical analyses such as discriminant analysis and logistic regression analysis were conducted to develop a mobilization criterion using geomorphological and geological factors. Ten parameters of geomorphological and geological factors were used as independent variables, and 466 cases (228 non-mobilization cases and 238 mobilization cases) were investigated for the statistical analyses. First of all, Fisher's discriminant function was used for the mobilization criterion. It showed 91.6 percent in the accuracy of actual mobilization cases, but homogeneity condition of variance and covariance between non-mobilization and mobilization groups was not satisfied, and independent variables did not follow normal distribution, either. Second, binomial logistic analysis was conducted for the mobilization criterion. The result showed 92.3 percent in the accuracy of actual mobilization cases, and all assumptions for the logistic analysis were satisfied. Therefore, it can be concluded that the mobilization criterion for debris-flow using binomial logistic regression analysis can be effectively applied for the prediction of debris-flow hazard analysis.

A Study on the Parameter Estimation for Testing Effort Function of Software (소프트웨어 테스트 노력 함수의 파라미터 산출에 관한 연구)

  • 최규식;김필중
    • Journal of Information Technology Applications and Management
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    • v.11 no.2
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    • pp.191-204
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    • 2004
  • Many software reliability growth model(SRGM) have been proposed for past several decades. Most of these propositions assumed the S/W debugging testing efforts be constant or even did not consider them. A few papers were presented as the software reliability evaluation considering the testing effort was important afterwards. The testing effort forms which have been presented by this kind of papers were exponential, Rayleigh, Weibull, or Logistic functions, and one of these 4 types was used as a testing effort function depending on the S/W developing circumstances. We consider the methology to evaluate the SRGN using least square estimator(LSE) and maximum likelihood estimator(MLE) for those 4 functions, and then examine parameters applying actual data adopted from real field test of developing S/W.

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Acceleration the Convergence and Improving the Learning Accuracy of the Back-Propagation Method (Back-Propagation방법의 수렴속도 및 학습정확도의 개선)

  • 이윤섭;우광방
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.39 no.8
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    • pp.856-867
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    • 1990
  • In this paper, the convergence and the learning accuracy of the back-propagation (BP) method in neural network are investigated by 1) analyzing the reason for decelerating the convergence of BP method and examining the rapid deceleration of the convergence when the learning is executed on the part of sigmoid activation function with the very small first derivative and 2) proposing the modified logistic activation function by defining, the convergence factor based on the analysis. Learning on the output patterns of binary as well as analog forms are tested by the proposed method. In binary output patter, the test results show that the convergence is accelerated and the learning accuracy is improved, and the weights and thresholds are converged so that the stability of neural network can be enhanced. In analog output patter, the results show that with extensive initial transient phenomena the learning error is decreased according to the convergence factor, subsequently the learning accuracy is enhanced.

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Feature reduction for classifying high dimensional data sets using support vector machine (고차원 데이터의 분류를 위한 서포트 벡터 머신을 이용한 피처 감소 기법)

  • Ko, Seok-Ha;Lee, Hyun-Ju
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.877-878
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    • 2008
  • We suggest a feature reduction method to classify mouse function data sets, which integrate several biological data sets represented as high dimensional vectors. To increase classification accuracy and decrease computational overhead, it is important to reduce the dimension of features. To do this, we employed Hybrid Huberized Support Vector Machine with kernels used for a kernel logistic regression method. When compared to support vector machine, this a pproach shows the better accuracy with useful features for each mouse function.

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Evaluation on the Prediction Model for the Compressive Strength of Concrete mixing Blast Furnace Slag Powder at early-aged by Maturity Method (적산온도에 의한 고로슬래그 미분말 혼입 콘크리트의 초기재령 압축강도의 예측 모델식 적용성 평가)

  • Yang, Hyun-Min;Park, Won-Jun;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2012.05a
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    • pp.251-252
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    • 2012
  • The exiting studies on the strength prediction by maturity method is mainly focused on concrete using OPC, meanwhile the study on the concrete mixing blast furnace slag powder (BFSP) is insufficient. The purpose of this study is to investigate the relationships between compressive strength and equivalent age by existing Maturity functions, i.e., Nurse-saul function Arrhenius function. This study also compared and examined the strength prediction of concrete mixing BGSP using ACI model and Logistic Curve prediction equation. Therefore, it is intended that fundamental data are presented for quality management and process management of concrete mixing BFSP.

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Support Vector Bankruptcy Prediction Model with Optimal Choice of RBF Kernel Parameter Values using Grid Search (Support Vector Machine을 이용한 부도예측모형의 개발 -격자탐색을 이용한 커널 함수의 최적 모수 값 선정과 기존 부도예측모형과의 성과 비교-)

  • Min Jae H.;Lee Young-Chan
    • Journal of the Korean Operations Research and Management Science Society
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    • v.30 no.1
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    • pp.55-74
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    • 2005
  • Bankruptcy prediction has drawn a lot of research interests in previous literature, and recent studies have shown that machine learning techniques achieved better performance than traditional statistical ones. This paper employs a relatively new machine learning technique, support vector machines (SVMs). to bankruptcy prediction problem in an attempt to suggest a new model with better explanatory power and stability. To serve this purpose, we use grid search technique using 5-fold cross-validation to find out the optimal values of the parameters of kernel function of SVM. In addition, to evaluate the prediction accuracy of SVM. we compare its performance with multiple discriminant analysis (MDA), logistic regression analysis (Logit), and three-layer fully connected back-propagation neural networks (BPNs). The experiment results show that SVM outperforms the other methods.

Studies on the Mathematical Analysis of Growth Kinetics in Tobacco (Nicotiana tabacum L. ) I. Growth Curve and Growth Velocity of Total Dry Weight. (담배의 생장반응에 관한 수리해석적 연구 I. 전건물중의 생장곡선과 생장속도)

  • 김용암;변주섭
    • Journal of the Korean Society of Tobacco Science
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    • v.3 no.2
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    • pp.109-114
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    • 1981
  • This experiment was conducted with three varieties (Hicks, Burley 21, Sohyang) and cropping systems (Improved mulching, Mulching, Non mulching) of NC 2326 to analyze growth kinetics by means of growth function involving its velocity and accelerated velocity. The basic growth data were obtained by harvest method at interval of ten days from transplanting to hundred days and analyzed by , regression equation, determinant of matrix, and differentiation. The plot of total dry weight of leaves, stalk and roots per a plant vs. time forms a sigmoid curve and its function fitted logistic satisfactorily. Tobacco plant grows at an accelerated velocity. And growth velocity, symmetric about an inflection point, is proportional to biomass attained and to the difference between biomass attained and the maximum, and to the decrease according to the biomass. Of varieties and cropping systems, the most maximum velocity was 9.58g per day per plant in mulching cultivation of NC 2326 and maximum accelerated velocity was 264mg per $day^2$ per plant in Burley 21.

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Demand Forecasting for New Service using the Diffusion Model (확산모형 (Diffusion Model)을 이용한 새로운 서비스 수요예측)

  • Kim, Gyeong-Taek;Park, Se-Gwon
    • Journal of Korean Institute of Industrial Engineers
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    • v.13 no.1
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    • pp.25-29
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    • 1987
  • When the historical data are available, the diffusion model, which describes the time pattern of the adoption process of a new product or technology or service, has been used as a reasonable predictor in the telecommunication demand forecasting area. This paper shows that the diffusion model is applicable when the historical data are not available. The model used is in the form of a "logistic" function. The parameters of the function are estimated using the questionnaire and the historical data of reference products. From the questionnaire, an initial and an upper limit long run value of the market share are estimated, and the diffusion time to the upper limit value is determined by the relation between the investment and the utility.

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