• Title/Summary/Keyword: University class model

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A design of Cooperative Instruction Model based on WWW to improve learning attitude in a small-scale class (소인수학급에서 학습태도에 변화를 주는 웹기반 협동수업모델의 설계)

  • Sung, Young-Hoon;Lee, Jae-Inn
    • Journal of The Korean Association of Information Education
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    • v.6 no.2
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    • pp.154-162
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    • 2002
  • In a small-scale class, children gradually lose interests in studying and develop negative and passive attitudes in class activities due to the uniform education. Although many cooperative instruction WBI models are studied and designed, there has not been any research on cooperative instruction model appropriate for a small-scale class. In this study, instructors participate in classes, each in connection with other small-scale classes, and WWW based cooperative instruction model, WIEZ, which can affect students' learning attitude on long-term basis, was designed and embodied. Currently, WIEZ is being under experimental test in three schools at Kyung-nam where instructors design classes, and students divided into groups participate in classes in this system.

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Minimax Average MSE Designs for Estimating Mean Responses

  • Joong-Yang Park
    • Communications for Statistical Applications and Methods
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    • v.3 no.3
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    • pp.93-101
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    • 1996
  • The unknown response function is usually approximated by a low order polynomial model. Such an approximation always accompanies bias due to model departure. The minimax Average MSE (AMSE) designs are suggested for estimating mean responses. A class of first order minimax AMSE designs is derived and a specific first order minimax AMSE design is selected from the class by optimizing the secondary criterion related to the power of the lack of fit test.

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Severity-based Software Quality Prediction using Class Imbalanced Data

  • Hong, Euy-Seok;Park, Mi-Kyeong
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.4
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    • pp.73-80
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    • 2016
  • Most fault prediction models have class imbalance problems because training data usually contains much more non-fault class modules than fault class ones. This imbalanced distribution makes it difficult for the models to learn the minor class module data. Data imbalance is much higher when severity-based fault prediction is used. This is because high severity fault modules is a smaller subset of the fault modules. In this paper, we propose severity-based models to solve these problems using the three sampling methods, Resample, SpreadSubSample and SMOTE. Empirical results show that Resample method has typical over-fit problems, and SpreadSubSample method cannot enhance the prediction performance of the models. Unlike two methods, SMOTE method shows good performance in terms of AUC and FNR values. Especially J48 decision tree model using SMOTE outperforms other prediction models.

Life satisfaction and self-esteem of children from low-income class : Testing mediation model of depression (저소득층 아동의 삶의 만족도와 자아존중감 : 우울의 매개효과 검증)

  • Hong, Yeonran;Jang, Gunja;Choi, Cheungsook
    • Journal of the Korean Data and Information Science Society
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    • v.27 no.1
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    • pp.179-189
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    • 2016
  • The purpose of this study was to investigate the mediating effect of depression on the relationship between self-esteem and life satisfaction of children from low-income class. The subjects were 385 children from low-income class in two municipalities. As research methods, frequency, descriptive, correlation statistical analysis using SPSS 20.0 program was conducted. The hypothesized model was tested using structural equation model to identify that model fits best to the collected data. The analysis indicates that depression had direct and negative effects on the life satisfaction. Depression mediates partially the relationship between self-esteem and life satisfaction. This study provides theoretical and practical implications for increasing self-esteem had positive effects on decreasing depression and pressing for improvement of life satisfaction level of children from low-income class.

Analysis of Underwater Radiated Noise in Accordance with the ISO Standard and Class Notations Using the Hybrid Sound Propagation Model (하이브리드 음전달 모델을 이용한 ISO 및 선급별 수중방사소음 전달 특성 분석 )

  • Byungjun, Koh;Chul Won, Lee;Ji Eun, Lee;Keunhwa, Lee
    • Journal of the Society of Naval Architects of Korea
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    • v.59 no.6
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    • pp.362-371
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    • 2022
  • As considerable interests in noise emission from the ships have been increased, International Maritime Organization (IMO) standardized the Underwater Radiated Noise (URN) measurement process of commercial ships in deep seas by enacting the related ISO standard ISO 17208-1 and classification societies responded with the enactment or revision of corresponding notations. According to this trend, a new hybrid underwater sound propagation model based on underwater sound propagation theories was developed and its accuracy on analysis was verified through the result comparison with the results of other generally used models. Using the verified model, each URN propagation characteristics adjusted by the correction methods proposed in the ISO standard and class notations were analyzed and compared in two assumed URN measurement cases. The results showed that the effects of transmission loss corrections in the circumstances with less bottom reflections generally similar but they had rather large differences in the model analysis results with bottom-reflection-dominant conditions. It was concluded that the deep consideration of effective bottom-reflection-correction method should be made in future revisions of ISO standard and class notations.

Machine learning-based Predictive Model of Suicidal Thoughts among Korean Adolescents. (머신러닝 기반 한국 청소년의 자살 생각 예측 모델)

  • YeaJu JIN;HyunKi KIM
    • Journal of Korea Artificial Intelligence Association
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    • v.1 no.1
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    • pp.1-6
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    • 2023
  • This study developed models using decision forest, support vector machine, and logistic regression methods to predict and prevent suicidal ideation among Korean adolescents. The study sample consisted of 51,407 individuals after removing missing data from the raw data of the 18th (2022) Youth Health Behavior Survey conducted by the Korea Centers for Disease Control and Prevention. Analysis was performed using the MS Azure program with Two-Class Decision Forest, Two-Class Support Vector Machine, and Two-Class Logistic Regression. The results of the study showed that the decision forest model achieved an accuracy of 84.8% and an F1-score of 36.7%. The support vector machine model achieved an accuracy of 86.3% and an F1-score of 24.5%. The logistic regression model achieved an accuracy of 87.2% and an F1-score of 40.1%. Applying the logistic regression model with SMOTE to address data imbalance resulted in an accuracy of 81.7% and an F1-score of 57.7%. Although the accuracy slightly decreased, the recall, precision, and F1-score improved, demonstrating excellent performance. These findings have significant implications for the development of prediction models for suicidal ideation among Korean adolescents and can contribute to the prevention and improvement of youth suicide.

Estimation Model and Vertical Distribution of Leaf Biomass in Pinus sylvestris var. mongolica Plantations

  • Liu, Zhaogang;Jin, Guangze;Kim, Ji Hong
    • Journal of Korean Society of Forest Science
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    • v.98 no.5
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    • pp.576-583
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    • 2009
  • Based on the stem analysis and biomass measurement of 36 trees and 1,576 branches in Pinus sylvestris var. mongolica (Mongolian pine) plantations of Northeast China, this study was conducted to develop estimation model equation for leaf biomass of a single tree and branch, to examine the vertical distribution of leaf biomass in the crown, and to evaluate the proportional ratios of biomass by tree parts, stem, branch, and leaf. The results indicated that DBH and crown length were quite appropriate to estimate leaf biomass. The biomass of single branch was highly correlated with branch collar diameter and relative height of branch in the crown, but not much with stand density, site quality, and tree height. Weibull distribution function would have been appropriate to express vertical distribution of leaf biomass. The shape parameters from 29 sample trees out of 36 were less than 3.6, indicating that vertical distribution of leaf biomass in the crown was displayed by bell-shaped curve, a little inclined toward positive side. Apparent correlationship was obtained between leaf biomass and branch biomass having resulted in linear function equation. The stem biomass occupied around 80% and branch and leaf made up about 20% of total biomass in a single tree. As the level of tree class was increased from class I to class V, the proportion of the stem biomass to total biomass was gradually increased, but that of branch and leaf became decreased.

Localization of ripe tomato bunch using deep neural networks and class activation mapping

  • Seung-Woo Kang;Soo-Hyun Cho;Dae-Hyun Lee;Kyung-Chul Kim
    • Korean Journal of Agricultural Science
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    • v.50 no.3
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    • pp.399-406
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    • 2023
  • In this study, we propose a ripe tomato bunch localization method based on convolutional neural networks, to be applied in robotic harvesting systems. Tomato images were obtained from a smart greenhouse at the Rural Development Administration (RDA). The sample images for training were extracted based on tomato maturity and resized to 128 × 128 pixels for use in the classification model. The model was constructed based on four-layer convolutional neural networks, and the classes were determined based on stage of maturity, using a Softmax classifier. The localization of the ripe tomato bunch region was indicated on a class activation map. The class activation map could show the approximate location of the tomato bunch but tends to present a local part or a large part of the ripe tomato bunch region, which could lead to poor performance. Therefore, we suggest a recursive method to improve the performance of the model. The classification results indicated that the accuracy, precision, recall, and F1-score were 0.98, 0.87, 0.98, and 0.92, respectively. The localization performance was 0.52, estimated by the Intersection over Union (IoU), and through input recursion, the IoU was improved by 13%. Based on the results, the proposed localization of the ripe tomato bunch area can be incorporated in robotic harvesting systems to establish the optimal harvesting paths.

Application of Dynamic Complex Instruction Model (DCIM) to a Biology Class in the Graduate School and Its Effect in Changing Self-Directed Learning Ability and Academic Motivation Types (대학원 생물학 강좌에서 역동적 복합 수업 모형(DCIM)의 적용이 자기주도적 학습 능력과 학습 동기 유형의 변화에 미치는 영향)

  • Oh, Soonae
    • Journal of Science Education
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    • v.35 no.2
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    • pp.295-306
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    • 2011
  • Self-directed learning ability is more important than before. It is well-known that traditional teacher-directed lecture class, seminar-like oral presentation class, and even discussion/debate class have not been enough to enforce self-directed learning ability for students. To resolve the problem, a new dynamic complex instruction model (DCIM) was developed for undergraduate and graduate students and a basic frame of DCIM was published by Oh (2010). Here, it is examined if the application of DCIM to a biology class of graduate school can cause improvement of self-directed learning ability. For this, the self-directed learning readiness scale (West & Bentley, 1990) translated by Ryu (1997) and motivation scale (Hayamizu. 1997) translated by Oh (2001) were employed, and then measurements performed with the translated scales were done in the beginning and the last of two DCIM-adapted graduate biology classes at K university, Daegu, South Korea in the first semester of the year 2010. The results show that self-directed learning ability could be significantly improved through the DCIM-adapted class, compared to the result of a teacher-directed lecture class as a control group. With respect to the motivation, there was not found any statistically significant difference between control and experiment groups of graduate students. The present study seems to be meaningful in that it is the first work proving the effect of improvement of self-directed learning ability of graduate students through the DCIM-adapted classes.

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The Prediction of DEA based Efficiency Rating for Venture Business Using Multi-class SVM (다분류 SVM을 이용한 DEA기반 벤처기업 효율성등급 예측모형)

  • Park, Ji-Young;Hong, Tae-Ho
    • Asia pacific journal of information systems
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    • v.19 no.2
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    • pp.139-155
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    • 2009
  • For the last few decades, many studies have tried to explore and unveil venture companies' success factors and unique features in order to identify the sources of such companies' competitive advantages over their rivals. Such venture companies have shown tendency to give high returns for investors generally making the best use of information technology. For this reason, many venture companies are keen on attracting avid investors' attention. Investors generally make their investment decisions by carefully examining the evaluation criteria of the alternatives. To them, credit rating information provided by international rating agencies, such as Standard and Poor's, Moody's and Fitch is crucial source as to such pivotal concerns as companies stability, growth, and risk status. But these types of information are generated only for the companies issuing corporate bonds, not venture companies. Therefore, this study proposes a method for evaluating venture businesses by presenting our recent empirical results using financial data of Korean venture companies listed on KOSDAQ in Korea exchange. In addition, this paper used multi-class SVM for the prediction of DEA-based efficiency rating for venture businesses, which was derived from our proposed method. Our approach sheds light on ways to locate efficient companies generating high level of profits. Above all, in determining effective ways to evaluate a venture firm's efficiency, it is important to understand the major contributing factors of such efficiency. Therefore, this paper is constructed on the basis of following two ideas to classify which companies are more efficient venture companies: i) making DEA based multi-class rating for sample companies and ii) developing multi-class SVM-based efficiency prediction model for classifying all companies. First, the Data Envelopment Analysis(DEA) is a non-parametric multiple input-output efficiency technique that measures the relative efficiency of decision making units(DMUs) using a linear programming based model. It is non-parametric because it requires no assumption on the shape or parameters of the underlying production function. DEA has been already widely applied for evaluating the relative efficiency of DMUs. Recently, a number of DEA based studies have evaluated the efficiency of various types of companies, such as internet companies and venture companies. It has been also applied to corporate credit ratings. In this study we utilized DEA for sorting venture companies by efficiency based ratings. The Support Vector Machine(SVM), on the other hand, is a popular technique for solving data classification problems. In this paper, we employed SVM to classify the efficiency ratings in IT venture companies according to the results of DEA. The SVM method was first developed by Vapnik (1995). As one of many machine learning techniques, SVM is based on a statistical theory. Thus far, the method has shown good performances especially in generalizing capacity in classification tasks, resulting in numerous applications in many areas of business, SVM is basically the algorithm that finds the maximum margin hyperplane, which is the maximum separation between classes. According to this method, support vectors are the closest to the maximum margin hyperplane. If it is impossible to classify, we can use the kernel function. In the case of nonlinear class boundaries, we can transform the inputs into a high-dimensional feature space, This is the original input space and is mapped into a high-dimensional dot-product space. Many studies applied SVM to the prediction of bankruptcy, the forecast a financial time series, and the problem of estimating credit rating, In this study we employed SVM for developing data mining-based efficiency prediction model. We used the Gaussian radial function as a kernel function of SVM. In multi-class SVM, we adopted one-against-one approach between binary classification method and two all-together methods, proposed by Weston and Watkins(1999) and Crammer and Singer(2000), respectively. In this research, we used corporate information of 154 companies listed on KOSDAQ market in Korea exchange. We obtained companies' financial information of 2005 from the KIS(Korea Information Service, Inc.). Using this data, we made multi-class rating with DEA efficiency and built multi-class prediction model based data mining. Among three manners of multi-classification, the hit ratio of the Weston and Watkins method is the best in the test data set. In multi classification problems as efficiency ratings of venture business, it is very useful for investors to know the class with errors, one class difference, when it is difficult to find out the accurate class in the actual market. So we presented accuracy results within 1-class errors, and the Weston and Watkins method showed 85.7% accuracy in our test samples. We conclude that the DEA based multi-class approach in venture business generates more information than the binary classification problem, notwithstanding its efficiency level. We believe this model can help investors in decision making as it provides a reliably tool to evaluate venture companies in the financial domain. For the future research, we perceive the need to enhance such areas as the variable selection process, the parameter selection of kernel function, the generalization, and the sample size of multi-class.