• Journal of the Korean Society for Library and Information Science
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• v.40 no.2
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• pp.217-242
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• 2006

This Study reviewed 86 research articles using inferential statistics published in 2001-2004 in 4 korean core journals in the field of library and information science. Sampling methods, response rates and nonresponse bias, reliability test, and inferential statistic techniques used in the articles were critically reviewed and analyzed. Nonprobability sampling was mostly used. Average response rate was 74.47%. Parametric statistics were mostly used. Some misunderstandings in using each inferential statistics, especially Reliability Test, Multiple Regression, Factor Analysis, MDS, etc. were reported in this study.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.1
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• pp.45-52
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• 2016

This paper suggests a new method of finding regularization parameter for image restoration problems. Wiener filter requires priori information such that power spectrums of original image and noise. Constrained least squares restoration also requires knowledge of the noise level. If the prior information is not available, separate optimization functions for Tikhonov regularization parameter are suggested in the literature such as generalized cross validation and L-curve criterion. In this paper, self-regularization method that connects bias term of augmented linear system and smoothing term of Tikhonov regularization is introduced in the frequency domain and applied to the image restoration problems. Experimental results show the effectiveness of the proposed method.

• Journal of the Korean Data and Information Science Society
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• v.23 no.6
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• pp.1093-1102
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• 2012

In this paper, we predicted the interest spread using the VAR (vector autoregressive) model. Variables used in the VAR model were selected among 56 domestic and foreign macroeconomic time series through crosscorrelation and Granger causality test. The performance of the VAR model was compared with the univariate time series model, AR (autoregressive) model, in view of MAPE (mean absolute percentage error) and RMSE (root mean square error) of forecasts for the last twelve months.

• Journal of the Korean Data and Information Science Society
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• v.24 no.6
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• pp.1439-1448
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• 2013

The analysis of variance for randomized block design or two way classification data is well known. In this paper, particularly, we considered two stage nested design in which the levels of one factor is not identical for different levels of another factor. We investigate the structural properties of two stage nested design and the properties of error sum of squares for random effect model. For the application of two way nested design, we consider two-period crossover design which is used commonly for the equivalence test to bio-similar product. The confidence interval estimation of the difference of two population means in the crossover design is discussed based on statistical package SPSS.

• The Journal of the Korea institute of electronic communication sciences
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• v.11 no.11
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• pp.1129-1134
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• 2016

This paper suggests a new method of finding regularization parameter for image restoration problems. If the prior information is not available, separate optimization functions for Tikhonov regularization parameter are suggested in the literature such as generalized cross validation and L-curve criterion. In this paper, unified Bayesian interpretation of Tikhonov regularization is introduced and applied to the image restoration problems. The relationship between Tikhonov regularization parameter and Bayesian hyper-parameters is established. Update formular for the regularization parameter using both maximum a posteriori(: MAP) and evidence frameworks is suggested. Experimental results show the effectiveness of the proposed method.

• Tunnel and Underground Space
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• v.19 no.5
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• pp.421-431
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• 2009

As an indirect method, Schmidt hammer test has been employed to investigate correlation between uniaxial compressive strengths and blow values. To conduct the experiment, researchers have examined 11 types (1,417 blocks) of rock, which include igneous, metamorphic and sedimentary rocks in Korea. Every kind of rocks shows different blow behaviors in which correlations of rocks have been analyzed, thus leading to results in new formulas for strength predictions. Cross-check for reliability demonstrates high confidence. Newly proposed test method is highly valued for future research on Korean rocks.

• The Korean Journal of Applied Statistics
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• v.32 no.6
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• pp.909-922
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• 2019

In this paper, we study the adaptive least absolute shrinkage and selection operator (LASSO) for the unstable autoregressive (AR) model. To identify the existence of the unit root, we apply the adaptive LASSO to the augmented Dickey-Fuller regression model, not the original AR model. We illustrate our method with simulations and a real data analysis. Simulation results show that the adaptive LASSO obtained by minimizing the Bayesian information criterion selects the order of the autoregressive model as well as the degree of differencing with high accuracy.

• Journal of the Korea Convergence Society
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• v.11 no.12
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• pp.451-456
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• 2020

This study compared the utility of walking aids, and activities of daily life depending on the ability of people with mobility disabilities to use walking aids. Data were extracted from the Korea Welfare Panel Study in 2014. Data of 435,947 individuals were analyzed using chi-square and t-tests. The findings from this study showed that disabled persons who cannot use walking aids independently were more likely to have a severe disability level and a lower level of daily activities than the independent group. The level of social participation and leisure activities were also significantly lower in the dependent than the independent group. Therefore, walking aids should be tailored for individuals depending on their level of independence for using walking aids.

• Journal of the Korean Geotechnical Society
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• v.22 no.10
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• pp.139-150
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• 2006

A study has been made of the Schmidt hammer rebound test for the estimation of engineering and physical characteristics of sedimentary rocks. As there is no universal formular for the estimation of rock strength due to geological conditions, in this study only sedimentary rocks are adopted to testing. The aim of study is to make the information more meaningful and useful for engineers and contractors by providing rapid, cheap and easy method. The obtained parameters were correlated and regression equations were established among Schmidt hammer rebound number, uniaxial compressive strength, tangent Young's modulus, indirect tensile stress, water absorption and porosity of rocks with high coefficients of correlation with each other.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.05a
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• pp.519-522
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• 2020

1989년에 WWW(World Wide Web)이 도입 되면서 세계적으로 인터넷의 보급이 시작되었다. 정보화 시대라고 알려진 3차 산업혁명 이후로 대량의 정보들이 소셜 미디어를 통하여 생산되었다. 소셜미디어는 2007년에 인터넷 사용자들 중 56%의 이용률을 보였지만 2008년 2분기에는 75%의 이용률로 증가함에 따라 대부분의 사용자들이 많이 사용하며 의존하게 되었다. 또한 소셜 미디어를 통해 발생 되는 데이터들을 이용하여 기업들은 이윤 창출을 할 수 있다. 하지만 이러한 소셜 미디어는 악의적인 목적을 통해 주가 조작, 정치적 선동 등을 할 수 있는 가짜 뉴스와 허위 정보들을 생성할 수 있으며 이에 따라 대책이 시급하다. 또한 가짜 뉴스는 사람이 글을 작성할 수도 있지만 최근 인공지능 기술의 발달에 따라 프로그램을 통해 자동적으로 생성 될 수도 있다. 본 논문에서는 이와 같은 실제 뉴스와 인공지능을 기반으로 한 뉴스를 분석한다. Kaggle에서 실제 뉴스 데이터를 수집하여 헤드라인을 OpenAI의 GPT-2 언어 모델을 통해 뉴럴 가짜 뉴스를 생성 하였다. 파이썬의 NLTK 모듈을 이용하여 전처리를 진행하였고 t-검정과 박스 플롯을 활용하여 분석을 진행하였다. 분석된 주요 속성들을 의사결정트리를 통해 모델 검증을 하였고 k-fold 교차검증을 통해 분류 모델을 평가하였다. 결과로 전체 분류 정확도 평균 89%의 성능을 보여주었다.