• Title/Summary/Keyword: 왜도

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The Relation between Treeing Breakdown Prediction and Acoustic Emission in Low Density Polyethylene (저밀도 폴리에틸렌의 트리 파괴 예지와 음향방출과의 관계)

  • 백관현;심종탁;김재환
    • The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.8 no.2
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    • pp.77-84
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    • 1994
  • This paper is measured partial discharge of low density polyethylene by using acoustic emission measuring method when the electrical tree grow its length in LDPE. Acoustic emission's pulses and its amplitudes of partial discharge are measured by acoustic emission measuring devices. Theorem of skewness are used for breakdown prediction of LDPE. So, it is found that the breakdown of LDPE could be predicted by its skewness's value. There are two kind of specimen of no void and specimen of artificial void, this one's electrical tree grows very faster than that one's.

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A study on the distribution of the distance of Mal movement in Yut board game (윷놀이에서 말이 가는 거리의 분포)

  • Kim, Do-Hyeong;Oh, Chang-Hyuck
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.6
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    • pp.1281-1288
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    • 2010
  • We consider Yut board game with four Yut sticks which are of the same shape and the same size so that they have the same probability of showing back when they are tossed. Since, in Yut board game, a player have to toss four sticks one more when sawi Mo or sawi Yut appears, the player may be interested in the distance which Mal can move in one's turn. Therefore, the probability mass function of the distance is obtained and probabilities with several values of back probability are summarized in a table. Also, the expectation, the variance, the skewness, and the kurtosis of the distribution are calculated and their values are also tablized for some values of back probability.

Beach Profile Change and Equilibrium due to Irregular Waves in the Nearshore Region (천해 불규칙파에 의한 해빈변형 및 평형)

  • Kang, Hyo-Jin
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.8 no.1
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    • pp.95-102
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    • 1996
  • The skewness of near-bottom velocity distribution caused by the nonlinear interaction of the second order waves proposed by Wells (1967) has been re-evaluated. The direction of cross-shore sediment transport was related to the sign of the third moment (skewness) of velocity distribution, and a new concept of neutral depth which can explain the recovery of beach equilibrium after a disturbance is suggested. The seasonal change of beach profile due to the change of wave condition (storm-swell profile) is interpreted in terms of nonlinear interaction of the waves rather than the conventional wave steepness. The beach is eroded (storm profile) when the nonlinear interaction of the waves is strong (storm wave), whereas the beach is accreted (swell profile) when the nonlinear interaction is weak (swell wave).

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Firework plot as a graphical exploratory data analysis tool for evaluating the impact of outliers in skewness and kurtosis of univariate data (일변량 자료의 왜도와 첨도에서 특이점의 영향을 평가하기 위한 탐색적 자료분석 그림도구로서의 불꽃그림)

  • Moon, Sungho
    • The Korean Journal of Applied Statistics
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    • v.29 no.2
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    • pp.355-368
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    • 2016
  • Outliers and influential data points distort many data analysis measures. Jang and Anderson-Cook (2014) proposed a graphical method called a rework plot for exploratory analysis purpose so that there could be a possible visualization of the trace of the impact of the possible outlying and/or influential data points on the univariate/bivariate data analysis and regression. They developed 3-D plot as well as pairwise plot for the appropriate measures of interest. This paper further extends their approach to identify its strength. We can use rework plots as a graphical exploratory data analysis tool to evaluate the impact of outliers in skewness and kurtosis of univariate data.

Urban Flood Prediction using LSTM and SOM (LSTM과 SOM을 적용한 도시지역 침수예측)

  • Lee, Yeonsu;Yu, Jae-Hwan;Kim, Byunghyun;Han, Kun-Yeun
    • Proceedings of the Korea Water Resources Association Conference
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    • 2021.06a
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    • pp.325-325
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    • 2021
  • 딥러닝을 이용한 침수해석은 강우자료와 그에 대한 1차원 EPA-SWMM 결과인 총월류량을 인공신경망에 학습시키고, 학습시킨 인공신경망을 테스트하기 위해 또다른 강우자료를 인공신경망으로 예측해서, 이것이 해석결과를 얼마나 잘 나타내는지 확인하고, 인공신경망이 모의한 총월류량을 잘 나타낸다면 인공신경망을 잘 학습시킨 것으로 판단하여 새로운 강우가 발생했을 때 새로운 강우자료에 대해 매번 새로 1차원, 2차원해석을 하는 것을 대신하여 인공신경망만으로 총월류량을 예측할 수 있게 되는 것이다. 강우자료를 입력자료로 사용하게 되는데, 강우량만으로는 그 강우의 특성을 전부 나타낸다고 할 수 없기 때문에 지속기간과 총강우량, 왜도(skewness), 표준편차를 추가적인 입력자료로 사용한다. 1차원, 2차원 해석결과인 총월류량은 입력자료에 대한 타깃자료가 되어, 인공신경망을 테스트하거나 실제로 이용할 때 비슷한 지속기간과 총강우량, 왜도, 표준편차를 가진 강우가 발생했을 때 타깃자료를 이용해 총월류량을 예측하는 것이다. 인공신경망이 얼마나 잘 학습되었는지 확인하기 위해서 침수지도를 작성해볼 필요가 있다. 1차원, 2차원 모의해석으로 나온 총월류량과, 인공신경망을 이용해 예측한 총월류량을 이용해 각각 침수지도를 작성하여 시각적 자료로 변환하여 비교하고, 침수지도가 일치한다면 인공신경망이 잘 학습되었다고 판단할 수 있고, 새로운 강우가 발생하면 학습시킨 인공신경망을 통해 1차원, 2차원 모의해석을 하지 않고도 총월류량을 예측할 수 있다.

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Automatic fire detection system using Bayesian Networks (베이지안 네트워크를 이용한 자동 화재 감지 시스템)

  • Cheong, Kwang-Ho;Ko, Byoung-Chul;Nam, Jae-Yeal
    • The KIPS Transactions:PartB
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    • v.15B no.2
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    • pp.87-94
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    • 2008
  • In this paper, we propose a new vision-based fire detection method for a real-life application. Most previous vision-based methods using color information and temporal variation of pixel produce frequent false alarms because they used a lot of heuristic features. Furthermore there is also computation delay for accurate fire detection. To overcome these problems, we first detected candidated fire regions by using background modeling and color model of fire. Then we made probabilistic models of fire by using a fact that fire pixel values of consecutive frames are changed constantly and applied them to a Bayesian Network. In this paper we used two level Bayesian network, which contains the intermediate nodes and uses four skewnesses for evidence at each node. Skewness of R normalized with intensity and skewnesses of three high frequency components obtained through wavelet transform. The proposed system has been successfully applied to many fire detection tasks in real world environment and distinguishes fire from moving objects having fire color.

Molecular Phylogenetic Position of Abbottina springeri (Cypriniformes: Cyprinidae) Based on Nucleotide Sequences of RAG1 Gene (RAG1 유전자의 염기서열에 기초한 왜매치 Abbottina springeri (잉어목, 잉어과)의 분자계통학적 위치)

  • Kim, Keun-Yong;Bang, In-Chul
    • Korean Journal of Ichthyology
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    • v.22 no.4
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    • pp.273-278
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    • 2010
  • Partial nucleotide sequences of nuclear protein-coding recombination activating gene 1 (RAG1) gene of two Abbottina and five Microphysogobio species residing in Korea were analyzed to elucidate the molecular phylogenetic position of A. springeri Banarescu and Nalbant. In RAG1 tree A. rivularis was clearly separated from the monophyletic lineage composed of A. springeri, Biwia zezera and Microphysogobio species. Within this lineage B. zezera showed sister-group relationship to the monophyletic group composed of A. springeri and five Microphysogobio species. Thus, our phylogenetic tree revealed the polyphyletic nature of two Abbottina species from Korea, which result is well congruent with the previous phyletic assumption based on osteological features. The current classification of Abbottina and Microphysogobio based on morphological criteria, such as the presence or absence of papillae on lips and size of swim bladder with or without encapsulation, does not reflect their true evolutionary history.

Why Is Begging the Question a Fallacy?: the Purpose of Arguments and Evaluations of Begging the Question (선결문제 요구의 오류는 왜 오류인가?: 논증의 목적과 선결문제 요구의 오류 평가)

  • Sunwoo, Hwan
    • Korean Journal of Logic
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    • v.19 no.2
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    • pp.185-232
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    • 2016
  • In order to explain why begging the question is a fallacy, some of the challenges must be met. First we need to understand what begging the question is in subtle ways. In addition, it is necessary to reflect on the nature and the purpose of arguments in order to explain why begging the question is a fallacy. In this paper, I first have a general proposal about the main purpose of arguments. Then I place my own multi-layered theory of begging the question proposed in a previous study in the context of the proposals in this paper for the main purpose of arguments. Moreover, I develop a more comprehensive theory of why begging the question is a fallacy. Finally, I examine and criticize the main previous theories of begging the question, such as Frank Jackson's theory, Douglas Walton's theory, David Sanford's theory, John Biro's theory.

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An Analysis of the Effects of WTI on Korean Stock Market Using HAR Model (국내 주식시장 변동성에 대한 국제유가의 영향: 이질적 자기회귀(HAR) 모형을 사용하여)

  • Kim, Hyung-Gun
    • Environmental and Resource Economics Review
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    • v.30 no.4
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    • pp.535-555
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    • 2021
  • This study empirically analyzes the effects of international oil prices on domestic stock market volatility. The data used for the analysis are 10-minute high-frequency data of the KOSPI index and WTI futures price from January 2, 2015, to July 30, 2021. For using the high-frequency data, a heterogeneous autoregression (HAR) model is employed. The analysis model utilizes the advantages of high frequency data to observe the impact of international oil prices through realized volatility, realized skewness, and kurtosis as well as oil price return. In the estimation, the Box-Cox transformation is applied in consideration of the distribution of realized volatility with high skewness. As a result, it finds that the daily return fluctuation of the WTI price has a statistically significant positive (+) effect on the volatility of the KOSPI return. However, the volatility, skewness, and kurtosis of the WTI return do not appear to affect the volatility of the KOSPI return. This result is believed to be because the volatility of the KOSPI return reflects the daily change in the WTI return, but does not reflect the intraday trading behavior of investors.

Effect of GA3 Treatment on Seed Germination, Seedling Growth and Useful Component Content of Angelica acutiloba (Siebold & Zucc.) Kitagawa (GA3 처리 왜당귀의 종자 발아, 유묘 생육 및 유용성분 특성 분석)

  • Dae Hui Jeong;Hong Woo Park;Young Ki Kim;Hae Yun Kwon
    • Korean Journal of Plant Resources
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    • v.36 no.5
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    • pp.508-516
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    • 2023
  • Germination, growth characteristics, and content of useful components were analyzed through GA3 treatment of Angelica acutiloba (Siebold & Zucc.) Kitagawa seeds, to provide basic data for cultivation technology. The moisture absorption rate of the seeds was 62.07% after 2 hours of soaking, and the highest value was 122.15% after 48 hours. The appropriate seed germination temperature for the species ranged from 10℃ to 25℃. It was confirmed that the growth of seedlings increased as the GA3 concentration increased, but there was no significant difference in the content of useful components according to the GA3 treatment.