• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.8
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• pp.647-651
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• 2001

The dielectric breakdown of epoxy composites used for transformers was experimented and then its data were applied to Weibull distribution probability. First of all, speaking of dielectric breakdown properties, the more hardener increased, the stronger breakdown strength became at low temperature because of cross-linked density by the virtue of ester radical. The breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised and the electric filed is concentrated. In the case of filled specimens with treating silane, the breakdown strength become much higher. Finally, from the analysis of weibull distribution, it was confirmed that to low allowed breakdown probability under 0,.1%, the applied field value needed to be under 21.5MV/cm.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05b
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• pp.159-163
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• 2003

In this study, the DC dielectric breakdown of epoxy composites used for PCB material was experimented and then its data were simulated by Weibull distribution equation. The more hardener increased the stronger breakdown strength at low temperature because of cross-linked density by the virtue of ester radical, and the breakdown strength of specimens with filler was lower than it of non-filler specimens because it is believed that the adding filler forms interface and charge is accumulated in it, therefore the molecular motility is raised, the electric field is concentrated, and the acceleration of electron and the growth of electron avalanche are early accomplished. From the analysis of Weibull distribution, it was confirmed that as the allowed breakdown probability was given by 0.1[%], the applied field value needed to be under 21.5[kV/mm].

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.25 no.3
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• pp.82-92
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• 2021

In this study, we present a fast option pricing method for four asset equity-linked securities (ELS) using Brownian bridge. The proposed method is based on Monte Carlo simulation (MCS) and a Brownian bridge approach. Currently, three asset ELS is the most popular ELS among multi-asset ELSs. However, four asset ELS emerged as an alternative to three asset ELS under low interest rate environment to give higher coupon rate to investors. We describe in detail the computational solution algorithm for the four underlying asset step-down ELS. The numerical tests confirm the accuracy and speed of the method.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.23 no.3
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• pp.237-251
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• 2019

We extend the previous work [J. Korean Soc. Ind. Appl. Math. 21(3) 181] to two-and three-asset equity-linked securities (ELS). In the real finance market, two-or three-asset ELS is more popular than one-asset ELS. Therefore, we need to develop mobile platform for pricing the two-and three-asset ELS. The mobile implementation of the ELS pricing will be very useful in practice.

• Proceedings of the Korea Contents Association Conference
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• 2013.05a
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• pp.73-74
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• 2013

차세대 웹 기술인 시맨틱 웹(Semantic Web)이 각광을 받음에 따라, 시맨틱 웹과 관련된 다양한 기술들이 활발히 연구되고 있다. 특히, 시맨틱 웹의 핵심 사례인 링크드 데이터(Linked Data)는 웹으로 접근 가능한 형태의 URI로 시맨틱 데이터를 표현하고 서로 연결함으로써, 오픈 데이터로서 상호운용성 극대화 및 데이터의 통합을 용이하게 한다. 이는 바이오인포매틱스 기술 발전과 결합하여 웹에서 바로 이용 가능한 많은 의학 링크드 데이터 생산과 이를 활용한 다양한 의학용어 검색 서비스 개발 결과를 가져왔다. 하지만, 기존 의학용어 검색 서비스들은 각 기관이 보유하고 있는 의학정보를 기반으로 서비스되기 때문에 다양하고 정확한 정보를 얻기 위해서는 많은 시간과 노력을 투자해야 한다. 그래서 본 논문에서는 척추 분야 의학 관련 링크드 데이터를 활용해 정확도가 높고 확장이 용이한 척추정보 검색 서비스를 제안한다.

• Journal of Preventive Medicine and Public Health
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• v.53 no.3
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• pp.164-167
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• 2020

Objectives: As of March 3, 2020, the Shincheonji religious group accounted for the majority of Korean cases of coronavirus disease 2019 (COVID-19). Nonetheless, the most likely cause of the broad spread of COVID-19 among members of the Shincheonji religious group remains largely unknown. Methods: We obtained data of laboratory-confirmed cases related to the Shincheonji religious group from press releases by Korean public health authorities and news reports. We measured the period from the date of illness onset to the date of COVID-19 confirmation. Results: We analysed data from 59 cases (median age, 30 years). The estimated median period between the date of symptom onset and the date of COVID-19 confirmation was 4 days (95% confidence interval, 1-12). Conclusions: There was a delay in COVID-19 confirmation from the date of illness onset among the cases linked to the Shincheonji religious group. This delay likely contributed to the occurrence of many cases of COVID-19 in the group.

• Journal of the Korean Society for Precision Engineering
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• v.12 no.11
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• pp.140-147
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• 1995

This paper deals with conversion from the STL file to the Slice to the Slice cross-sectional information for Stereolithography. The STL file is widely used for Stereolithography, but it is very difficult to convert STL file into Slice file directly. Because it consists of an ordered list of triangular net without any topological information other than the orientation of each facet. So, The system is accomplished by data flow through several intermediate stages such as Reference. SL1. .SL2L. .SL3. and .SLC file. The data processing is performed in 5 steps: 1) Create a Reference file including common information. 2) Modify STL file within the effective range of SL machine. 3) Calculate a point of intersection between plane equation and line equation. 4) Sort z values in ascending order using quick sort algorithm. 5) Search the adjacent points and formulate a closed loop usingsingly linked linear list. The system is developed by using Borland C++ 3.1 compiler in the environment of Pentium PC, and verified to be satisfactory by making some prototypes of electric household appliances.

• International Journal of Computer Science & Network Security
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• v.24 no.6
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• pp.99-108
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• 2024

The Internet of Things (IoT) is a novel concept that allows a large number of objects to be connected to the Internet while also allowing them to be controlled remotely. The Internet of Things is extensive and has become an almost inseparable part of our daily lives. Users' personal data is frequently obtained by these linked gadgets and stored online. In recent years, the security of acquired data has become a major concern. As devices grow more linked, privacy and security concerns grow more pressing, and they must be addressed as soon as possible. IoT implementations and devices are particularly vulnerable to attacks that might adversely affect customer security and privacy, which might have an impact on their practical utility. The goal of this study is to bring attention to the security and privacy concerns that exist in IoT systems. To that purpose, the paper examines security challenges at each level of the IoT protocol stack, identifies underlying impediments and critical security requirements, and provides a rapid overview of available security solutions for securing IoT in a layered environment.

• Convergence Security Journal
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• v.20 no.2
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• pp.77-83
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• 2020

According to a statistical survey, despite the continuous improvement of the economic level, the participation rate of donations is decreasing. As a cause of this phenomenon, the problem of reliability of donation organizations is a big part. In order to increase viewers' intention to donate, this study developed a donation campaign linked data service that shows information that can increase the credibility of donation organizations and storytelling of donation recipients. Specifically, a user scenario of a data service that is properly operated in conjunction with a donation campaign that is broadcast shortly was defined, and a user interface was designed by reflecting the characteristics of the TV platform. In addition, a prototype based on the DVB-MHP standard was developed to analyze the effect of the data service utilization on viewers' intention to donate.

• Convergence Security Journal
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• v.22 no.2
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• pp.91-98
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• 2022

Because the movie has the characteristics of a cultural product where experience is important, a promotional strategy is used to convert viewers into movie audiences by providing indirect experiences of movies through professional movie information programs. Considering that the movie information program is a strategic publicity medium that raises the audience's intention to watch a movie, a study on the data service that provides useful additional information to the viewer in conjunction with the movie information program is meaningful. Against this background, this study contains the core research contents in the development of data service linked with movie information program. Specifically, additional information of the movie information program was defined. And to provide the additional information to the data service, the digital broadcasting international standard DVB-SI-based additional information transmission method was devised.