• The Bulletin of The Korean Astronomical Society
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• v.38 no.2
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• pp.87.1-87.1
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• 2013

Ellerman bombs(EB) are small-scale bright features observed best in the wings of H alpha line. We used the Fast Imaging Solar Spectrograph(FISS) with the 1.6m New Solar Telescope at Big Bear Solar Observatory, in order to investigate characteristics of each EB. We analyzed H alpha line profiles of EBs, and classified EBs by their contrast profiles. To analyse characteristics of EBs, we applied power-law fitting ($C={\alpha}{\Delta}{\lambda}^{-n}$) to the EB contrast profiles. The amplitude ${\alpha}$ is a measure of the strength of an EB event (or the amount of released energy), and the power-law index n is a measure of spatial concentration of energy in the higher layers of the solar atmosphere. With the two parameters, we classified EBs into a few groups. We try to understand the physical properties of each group.

• 제어로봇시스템학회:학술대회논문집
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• 1991.10a
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• pp.469-475
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• 1991

In this paper, we suggest the exact perturbation analysis(Exact_PA) technique with respect to the buffer storage in tandem queueing networks, through which the optimal buffer storage design problem is considered. The discrete event dynamic equations for the departure time of a customer are presented together with the basic properties of Full Out(FO) and No Input(NI) with respect to the buffer storage. The new perturbation rules with respect to the buffer storage are suggested, from which the exact perturbed path can be obtained. The optimal buffer storage problem is presented by introducing a performance measure consisting of the throughput and the buffer storage cost. An optimization algorithm maximizing this performance measure is derived by using the Exact_PA technique. The proposed perturbation analysis technique and the optimization algorithm are validated by numerical examples.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.469-474
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• 2008

The reason for crashworthy landing gear is to contribute to the overall aircraft design goals in the event of a crash. One of crashworthy landing gear design approaches is inclusion of structural fuse. Structural fuse is used to control the mode of failure of landing gear. If structural fuse doesn't work at desired condition, other unexpected accidents can occur. In this paper, failure probability is calculated for landing gear structural fuse and improvement measure is introduced to improve failure probability of structural fuse.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.3
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• pp.371-374
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• 2009

In this paper, we introduce the concepts of effects and observable as generalizations of event and random variable, respectively. Also, we introduce the concept of $\sigma$-morphism and we investigate some results on $\sigma$-morphism as a probability measure on the set of effects.

• Communications for Statistical Applications and Methods
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• v.28 no.2
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• pp.151-159
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• 2021

In this article, our interest is to estimate the association between consecutive gap times which are subject to interval censoring. Such data are referred as doubly interval censored data (Sun, 2006). In a context of serial event, an induced dependent censoring frequently occurs, resulting in biased estimates. In this study, our goal is to propose a Kendall's 𝜏 based association measure for doubly interval censored data. For adjusting the impact of induced dependent censoring, the inverse probability censoring weighting (IPCW) technique is implemented. Furthermore, a multiple imputation technique is applied to recover unknown failure times owing to interval censoring. Simulation studies demonstrate that the suggested association estimator performs well with moderate sample sizes. The proposed method is applied to a dataset of children's dental records.

• The Korean Journal of Applied Statistics
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• v.10 no.1
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• pp.189-201
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• 1997

The primary purpose of this study is to develop a measure of tracking by using a modified kappa statistic. Understanding tracking phenomena in epidemiologic studies is quite important, because precautionary measure can be made in the early stage of the outcome event. Several authors proposed measures of tracking. Among them we compared ours against McMahan's using a simulation study. Finally we applied our procedure and McMahan's to real data. We may conclude that our statistic is adequate in explaining and detecting the tracking phenomenon.

• Journal of Acupuncture & Meridian Studies
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• v.11 no.6
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• pp.355-360
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• 2018

Introductions: Pneumothorax is the most frequent severe acupuncture-related adverse event occurring at the GB 21 acupoint. This study used ultrasonography (US) to measure the depth of the GB 21 acupoint in adults and assessed its applicability for ensuring safe acupuncture practices. Materials and methods: A US probe was used to measure the vertical depth from the skin to the pleural line of the apex of the lungs at the right and left GB 21 acupoints. The sex, age, body weight, height, and body mass index of each person were recorded. Student t test and generalized estimating equations were used for statistical analysis. Results: Sixty women and 41 men with a median age of 29 years were included in this study. The depth of GB 21 increased with body weight, height, and body mass index (p < 0.001). The mean depth of GB 21 in men (17.4 mm) was greater than that in women (14.6 mm; p < 0.001). The depth difference between the right and left shoulders was significant in men (p < 0.001) but not in women. Conclusions: US can be used to measure GB 21 acupoint depth. Further control studies on its use to ensure safe clinical practices, including preventing acupuncture-related pneumothorax, are warranted.

• Journal of Korea Multimedia Society
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• v.17 no.11
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• pp.1325-1334
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• 2014

Recently game addiction of young people has become a social issue. Therefore, many studies, mostly surveys, have been conducted to diagnose game addiction. In this paper, we suggest how to distinguish levels of addiction based on EEG. To this end, we first classify four groups by the degrees of addiction to internet games (High-risk group, Vigilance group, Normal group, Good-user group) using CSG (Comprehensive Scale for Assessing Game Behavior) and then measure their Event Related Potential(ERP) in the Go/NoGo Task. Specifically, we measure the signals of P300, N400 and N200 from the channels of the NoGo stimulus and Go stimulus. In addition, we extract distinct features from the discrete wavelet transform of the EEG signal and use these features to distinguish the degrees of addiction to internet games. The experiments in this study show that High-risk and Vigilance group exhibit lower Go-N200 amplitude of Fz channel than Normal and Good-user groups. In Go-P300 and NoGo-P300 of Fz channel, High-risk and Vigilance groups exhibit higher amplitude than Normal and Good-user group. In Go-N400 and NoGo-N400 of Pz channel, High-risk and Vigilance group exhibit lower amplitude than Normal and Good-user group. The test after the learning study of the extracted characteristics of each frequency band from the EEG signal showed 85% classification accuracy.

• Journal of Distribution Science
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• v.16 no.10
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• pp.55-64
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• 2018

Purpose - The most important goal of corporate management is the maximization of firm value in the market. Executives of companies are making effort to increase corporate value and initiate various management strategies, which is to develop the products or service with value. Through these efforts, consumer satisfaction grows and loyalty increases, which leads to the positive change of customer satisfaction index. The purpose of this research is to find out the abnormal return after the KCSI(Korean Customer Satisfaction Index) is announced. Research design, data, and methodology - This research data is collected from 11 years' stock price in KOSPI market and KCSI. The authors analyze the abnormal return triggered by the announcement of KCSI through the event study. Results - First, newly enlisted companies in the KCSI show statistically significant short-term abnormal rate of return. Second, the value of the customer satisfaction index is not the level of customer satisfaction but the direction of the change in the CSI. Conclusion - Customer satisfaction has the important intangible asset in the marketing area. However, firms' investment for CS is not an easy decision, because of the difficulty to measure the effect on corporate market value. This research investigates the change of the market value after the announcement of KCSI. Based on the results, firms have to keep trying to increase KCSI relative to the previous year. And the small company has to struggle for being newly listed in the KCSI.

• Annual Conference on Human and Language Technology
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• 2018.10a
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• pp.101-105
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• 2018

이 논문은 가장 잘 알려진 어휘부중 하나인 워드넷의 활용 범위 확장을 위해 워드넷 신셋에 "사건구조 프레임(Event Structure Frame)"을 주석하는 연구에 관한 것이다. 워드넷을 비롯하여 현재 사용되고 있는 어휘부는 풍부한 어휘의미정보가 구조화되어 있지만, 사건구조에 관한 정보를 포함하고 있지는 않다. 이 연구의 가장 큰 기여는 워드넷에 사건구조 프레임을 추가함으로써 워드넷과의 연결만으로 핵심적인 어휘의미정보를 모두 추출할 수 있도록 해준다는 점이다. 예를 들어 텍스트 추론, 자연어처리, 멀티 모달 태스크 등은 어휘의미정보와 배경지식(상식)을 이용하여 태스크를 수행한다. 워드넷에 대한 사건구조 주석은 자동사건구조 주석 시스템인 GESL을 이용하여 워드넷 신셋에 있는 예문에 먼저 자동 주석을 하고, 오류에 대해 수동 수정을 하는 반자동 방식이다. 사전 정의된 23개의 사건구조 프레임에 따라 예문에 출현하는 타겟 동사를 분류하고, 해당 프레임과 매핑한다. 현재 이 연구는 시작 단계이며, 이 논문에서는 빈도 순위가 가장 높은 100개의 동사와 각 사건구조 프레임별 대표 동사를 포함하여 총 106개의 동사 레마에 대해 실험을 진행하였다. 그 동사들에 대한 전체 워드넷 신셋의 수는 1337개이다. 예문이 없어서 GESL이 적용될 수 없는 신셋을 제외하면 1112개 신셋이다. 이 신셋들에 대해 GESL을 적용한 결과 F-Measure는 73.5%이다. 향후 연구에서는 워드넷-사건구조 링크를 계속 업데이트하면서 딥러닝을 이용해 GESL 성능을 향상 할 수 있는 방법을 모색할 것이다.