• Title/Summary/Keyword: 단계선택법

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Quantitative EEG research by the brain activities on the various fields of the English education (영어학습 유형별 뇌기능 활성화에 대한 정량뇌파연구)

  • Kwon, Hyung-Kyu
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.3
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    • pp.541-550
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    • 2009
  • This research attempted to find out any implications for strategies to design and develop the connections between the activities of the brain function and the fields of English learning (dictation, word level, speaking, word memory, listening). Thus, in developing the brain based learning model for the English education, attempts need to be made to help learners to keep the whole brain toward learning. On this point, this study indicated the significant results for the exclusive brain location and the brainwaves on the each English learning field by the quantitative EEG analysis. The results of this study presented the guidelines for the balanced development of the left brain and the right brain to train the specific site of the brain connected to the English learning fields. In addition, whole brain training model is developed by the quantitative EEG data not by the theoretical learning methods focused on the right brain training.

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A study on Factors Influencing COVID-19 on depression and anxiety in university students (코로나-19가 대학생의 우울과 불안에 미치는 영향 요인 연구)

  • Chun, Yeol-Eo;Hwang, Hye-Young;Lee, Ha-Neung
    • Journal of the Korea Convergence Society
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    • v.13 no.4
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    • pp.583-591
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    • 2022
  • In this study, the depression and anxiety of university students in the COVID-19 situation were identified, and the effects on depression and anxiety were indicated. Subjects were chosen randomly, and for the method a step selection multiple regression analysis was used. As a result of checking the factors affecting the subjects' general characteristics, stress level, preventive rule compliance level, and daily vitality level on depression and anxiety, the factors that had significant influence on depression were CPDI(𝛽=.230, p=.000), and K-ANX(𝛽=.472, p=.000). Other factors such as CPDI(𝛽=.276, p=.000), EDAS(𝛽=-.127, p=.019) and K-DEP(𝛽=.482, p=.000) were analyzed to have significant effects on anxiety. Therefore, the results of this study are thought to be meaningful as basic data that can be used to establish educational and counseling activities that help university students adjust to society and academically in the COVID-19 situation.

Family Gaps Across the Wages Distribution in Korea (자녀유무별 여성임금격차(Family gap) : 소득분위에 따른 비교연구)

  • Huh, Soo-Yeon
    • Korean Journal of Social Welfare Studies
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    • v.43 no.2
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    • pp.345-366
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    • 2012
  • This study analyze Family gaps(the wage gap between mothers and non-mothers) across the wages distribution in Korea using 2008 Korean Labor and Income Panel Study. Analysis models include Heckman's two stage estimation to control women's labor participation selection and Quantile regression method to examine the effects of children at different points of the wage distribution. The result indicates that first, comparing non-mothers, mothers with one child suffer statistically significant hourly wage losses at 25th, 50th, and 75th distribution, however not significant effects are found at lowest(10th) and highest(90th) distribution. Second, comparing non-mothers, mothers with two more children suffer statistically significant hourly wage losses at all distribution. Family gap differs across the wage distribution and highest family gaps are found at 25th distribution. With these results, the author suggests universal family policies to support mothers' labor participation and the reconciliation of work and family.

Measurement strategy of a system parameters for the PI current control of the A.C. motor (교류 전동기의 PI 전류제어를 위한 시스템 파라미터 계측법)

  • Jung-Keyng Choi
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.16 no.5
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    • pp.223-229
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    • 2023
  • This Paper propose the method that measure main system parameters for PI(proportional-integral) current control of a.c. motor adopting the vector control technique. For current control, the PI control input is could be tuning by several selective methods. Among the several methods, the method that using the main system parameters, wire resistance and inductance, are frequently used. In this study, the technique to dissect and measure these two system parameters through the results of simple feedback control. This analytic measurement method is measuring parameters step by step dissecting the results of P control using simple proportional feedback gain about the unit step or multiple step reference command. This strategy is an real time analytic measurement method that calculate current control gains of torque component and flux component both for vector control of A.C. motor without introducing the further measurement circuits and complex measuring algorithms.

A Study on Sample Allocation for Stratified Sampling (층화표본에서의 표본 배분에 대한 연구)

  • Lee, Ingue;Park, Mingue
    • The Korean Journal of Applied Statistics
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    • v.28 no.6
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    • pp.1047-1061
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    • 2015
  • Stratified random sampling is a powerful sampling strategy to reduce variance of the estimators by incorporating useful auxiliary information to stratify the population. Sample allocation is the one of the important decisions in selecting a stratified random sample. There are two common methods, the proportional allocation and Neyman allocation if we could assume data collection cost for different observation units equal. Theoretically, Neyman allocation considering the size and standard deviation of each stratum, is known to be more effective than proportional allocation which incorporates only stratum size information. However, if the information on the standard deviation is inaccurate, the performance of Neyman allocation is in doubt. It has been pointed out that Neyman allocation is not suitable for multi-purpose sample survey that requires the estimation of several characteristics. In addition to sampling error, non-response error is another factor to evaluate sampling strategy that affects the statistical precision of the estimator. We propose new sample allocation methods using the available information about stratum response rates at the designing stage to improve stratified random sampling. The proposed methods are efficient when response rates differ considerably among strata. In particular, the method using population sizes and response rates improves the Neyman allocation in multi-purpose sample survey.

The Development of the Conceptual Model Visualization Program (개념모델 가시화 프로그램의 개발)

  • Choi, Hong-Seok;Okazaki, Akira
    • Science of Emotion and Sensibility
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    • v.13 no.3
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    • pp.573-580
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    • 2010
  • The earlier KANSEI evaluation had to choose not to overlap the opposite meaning of the words, had to choose that some figures are shown step by step and had to choose be prepared things in advance. However, The Study shows a method which visualizes the imprecise evaluations of human without choosing evaluation items which are not prepared figures. The program is used the way which is entered by hand-drawing that the subjects use the way to enter their subjective feelings about the evaluations presented by using the mouse or the graphics tablet. It is possible to express imprecise things about evaluations and the method of drawing is free. The program provides that we can express our thinking by drawing and there are a few limits and the prescribed standard. The area ratio of each circle is expressed as a pie chart and the area of circle what is drawn which is counted automatically at the same time. These things are possible not only to modify a transparency, a thickness of a line, a color and the area of circle what is drawn, but also to adjust the area of circle. The conceptual model is visualized that expresses something by hand-drawing such as a circle. The conceptual model has wide range of applications such as a personnel evaluation, a suffering evaluation and product evaluation. The program currently has been testing the effective of the program's possibilities which is used with the personnel appraisal tool of the nurses themselves who work in nurse support department where the St. Marianna University School of Medicine Hospital is. And also the program is proceeding with development to visualize the conceptual model by dynamic interfaces effectively and the program is applied such as KJ method and a program is used to express the kind of the patient's pain and its level.

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Attention-induced expansion in visual space (주의에 의한 시각 공간 확장)

  • 유명현;박정선;정찬섭
    • Korean Journal of Cognitive Science
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    • v.10 no.3
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    • pp.51-66
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    • 1999
  • Selective attention induces perceptual distortions. ranging from repulsion of objects located near the attended area(Suzuki & Cavanagh. 1997) to magnification of the u unattended objects (Tsal & Shalev. 1996). Two hypothetical mechanisms have been p postulated: a shift of receptive fields' positions away from the locus of attention(receptive-field-recruitment hypothesis) or the enlargement of perceived space around the a attended location(space-enlargement hypothesis). The present study distinguished between these hypotheses by investigating the spatial and temporal properties of attention-induced d distortions. Perceptual judgements on vernier alignment. line tilt. line length were used to measure attention-induced changes in perception. Attention was induced exogenously(by blinking a specific set of dots around the test stimuli} or endogenously(by instructing the subject to selectively attend the dots). After inducing attention. the test stimuli were briefly flashed. A staircase method was used to measure the attentional effect. A vertical line was perceived as repelled from the locus of attention. and a line segment appeared longer when attention was given to its vicinity. The effects decreased as the distance between the locus of attention or the time between the onset of attention and the stimulus presentation increased. The results imply that the space-enlargement hypothesis provides a better explanation for the attention-induced changes in perception than the receptive-field-recruitment hypothesis.

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Analysis of Volatile Components of a Chicken Model Food System in Retortable Pouches Using Multivariate Method (다변량 해석을 이용한 레토르트 파우치 계육 모형식품의 휘발성분 분석)

  • Choi, Jun-Bong;Kim, Jung-Hwan;Moon, Tae-Wha
    • Korean Journal of Food Science and Technology
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    • v.28 no.6
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    • pp.1171-1176
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    • 1996
  • The changes in volatiles of the model system were analyzed by GC and GC-MS before and after retorting. The GC data were analyzed statistically by applying the analysis of variance, and 42 peaks were selected at 5% significance level. Multivariate statistical analysis was performed with these 42 peaks as independent variables. Through the stepwise discriminant analysis, 8 peaks, which corresponded to the compounds such as 2-heptanone, cis-3-hexenal, 2-pentyl-furan, 1-methyl-trans-1,2-cyclohexanediol, 2-hexanone, 3-octanone, trans, trans-nona-2,4-dienal and 1-octen-3-ol, were obtained in sequence to distinguish the samples with and without retorting. The principal component analysis of a set of 8 independent variables resulted in 3 principal components which accounted for 96.1% of the variance, while the first principal component (PC 1) explained 76.5% of the total variance. In addition, through the factor analysis of the principal components, the peaks 11, 20 and 21 could be grouped togather in accordance with the direction and the size while the peaks 9, 33 and 39 constituted the second group in the direction.

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Prediction of golf scores on the PGA tour using statistical models (PGA 투어의 골프 스코어 예측 및 분석)

  • Lim, Jungeun;Lim, Youngin;Song, Jongwoo
    • The Korean Journal of Applied Statistics
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    • v.30 no.1
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    • pp.41-55
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    • 2017
  • This study predicts the average scores of top 150 PGA golf players on 132 PGA Tour tournaments (2013-2015) using data mining techniques and statistical analysis. This study also aims to predict the Top 10 and Top 25 best players in 4 different playoffs. Linear and nonlinear regression methods were used to predict average scores. Stepwise regression, all best subset, LASSO, ridge regression and principal component regression were used for the linear regression method. Tree, bagging, gradient boosting, neural network, random forests and KNN were used for nonlinear regression method. We found that the average score increases as fairway firmness or green height or average maximum wind speed increases. We also found that the average score decreases as the number of one-putts or scrambling variable or longest driving distance increases. All 11 different models have low prediction error when predicting the average scores of PGA Tournaments in 2015 which is not included in the training set. However, the performances of Bagging and Random Forest models are the best among all models and these two models have the highest prediction accuracy when predicting the Top 10 and Top 25 best players in 4 different playoffs.

Risk Assessment for a Steel Arch Bridge System Based upon Response Surface Method Compared with System Reliability (체계신뢰성 평가와 비교한 응답면기법에 의한 강재아치교의 위험성평가)

  • Cho, Tae-Jun
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.20 no.3
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    • pp.273-279
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    • 2007
  • Probabilistic Risk Assessment considering statistically random variables is performed for the preliminary design of an Arch Bridge. Component reliabilities of girders have been evaluated using the response surfaces of the design variables at the selected critical sections based on the maximum shear and negative moment locations. Response Surface Method (RSM) is successfully applied for reliability analyses lot this relatively small probability of failure of the complex structure, which is hard to be calculated by Monte-Carlo Simulations or by First Order Second Moment method that can not easily calculate the derivative terms in implicit limit state functions. For the analysis of system reliability, parallel resistance system composed of girders is modeled as a parallel series connection system. The upper and lower probabilities of failure for the structural system have been evaluated and compared with the suggested prediction method for the combination of failure modes. The suggested prediction method for the combination of failure modes reveals the unexpected combinations of element failures in significantly reduced time and efforts, compared with the previous permutation method or conventional system reliability analysis method.