• Information Systems Review
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• v.19 no.1
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• pp.1-23
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• 2017

Since the development of information communication technologies, social networking sites (SNSs) have been diffused to the world with benefits such as building and maintaining relationships among people. SNSs have become more popular with the development of mobile devices. Despite this advantage, SNSs also present unexpected effects on people, such as cyberbullying and identity theft. Cyberbullying has emerged as one of the most serious issues among people who use SNSs. In fact, almost 20% of teenagers confessed that they have been cyberbullied on SNSs. In consideration of this serious social issue, this study investigates the influences of self-disclosure and self-control on the cyberbullying victimization experience from the perspective of Social Exchange Theory. Self-disclosure is a basic characteristic of SNSs. It is classified into self-disclosure for access to SNS and self-disclosure for relationship building and maintaining on SNSs. The cyberbullying victimization experience is classified into being cyber-excluded and being cyber-attacked. We examine how two types of self-disclosure and self-control affect two types of cyberbullying victimization experience based on the survey data of people who are in their 20s and are greatly familiar with SNSs.

• The Korean Journal of Financial Management
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• v.26 no.3
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• pp.31-64
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• 2009

This article investigates the short-term cash flow exposures to Korea's major trading partners' currencies based on the kospi and kosdaq firm data from 2000 to 2008. The cash flow approach allows us to analyze the influence on operational performances of individual firm's hedging strategies. Taken all three foreign exchange rates together, more than 30% of the sample firms exhibit significant exposure. Given that the short-term cash flow is rather easy to hedge, the result proves a poor exchange rate risk management practices of Korean firms. Kosdaq firms are more exposed than Kospi firms. On the contrary to the previous researches using stock prices, the operational cash flows show a positive relationship with the value of foreign currencies. The exchange rate-firm sample further shows that the size and leverage affect the level of exposure.

• The Journal of the Korea Contents Association
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• v.19 no.8
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• pp.276-283
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• 2019

The purpose of this study is to evaluate the usefulness of automatic exposure control (AEC) by analyzing entrance surface dose (ESD) and entropy on using automatic exposure and manual exposure. The experimental method was to measure the dose by placing a semiconductor dosimeter on the Rando Phantom for the Pelvis, Abdomen, Skull, and Chest regions. The DICOM file was simultaneously acquired and then entropy was analyzed by using Matlab. As a result, when using the automatic exposure control, dose of all sites was lower than manual exposure's dose and entropy was high. In addition, paired t-test was performed for each item and p<0.05 was found in each item. In conclusion, the use of automatic exposure control can be a useful method to contribute to the optimization of the exposure dose and the image quality by reducing the amount of unnecessary radiation amount and information loss that can occur in X-ray examination.

• Journal of the Korean Data Analysis Society
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• v.20 no.6
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• pp.2841-2852
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• 2018

This study examines regression modeling method using zero-inflated distribution in relation to estimation of exposure distribution required in advertisement media planning. Exposure distribution is the percentage of audiences that are exposed each time the ad is repeated. Such an exposure distribution plays a very important role in providing basic information necessary for calculating various indicators for quantitatively measuring the advertising effect. Especially, due to the decrease of advertising price and the spread of various media, the frequency of the advertisement or the broadcasting of specific advertisements has been greatly increased compared to the past. As a result, the frequency of exposure is relatively decreasing. In this situation, the number of individuals who are not exposed to the media, that is, are not exposed to advertising structurally is increasing. This research proposes advertising exposure distribution models using a zero-inflated regression model, and conducts a comparative study using actual cases.

• The Journal of the Korea Contents Association
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• v.16 no.4
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• pp.434-441
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• 2016

Using bigdata analysis procedures, the present study sought to review and explore the various aspects of self-disclosure and boundary impermeability of worldwide twitter users. A total of 415 million tweets issued by 54 million users were collected during 6 months and the users of top 10 languages were investigated. And the effect of languages of twitter users on the boundary impermeability, disclosure rate of user profile, profile image, geographical information, URL in profile and user description were analyzed in this study. The results showed that the boundary impermeability and all the self-disclosure rates of twitter users (profile, profile image, geographical information, URL in profile, user description) were significantly (p<0.001) different among language groups of users. The self-disclosure rates and the average points of Portuguese, Indonesian and Spanish users were higher than those of Arabic, Japanese, Turkish and Korean users. The results also showed a positive relationship between boundary impermeability and the number of tweets (including retweets) issued by each users.

• Journal of Food Hygiene and Safety
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• v.35 no.5
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• pp.452-458
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• 2020

In this study we aimed to find out pesticide types with probability for underestimation of dietary exposure to pesticide residues in Korea by comparing the residue definitions between Korea and Codex standards. In addition, we sought to establish priorities regarding the necessity of review concerning pesticide types and their impacts based on the risk assessment and dietary exposure underestimation. As a result, we found that according to the residue definition information, 44 pesticides have probability for underestimation in terms of dietary exposure assessments. Among them, 24 pesticides have priority for review of dietary exposure underestimation and its impacts on risk assessment, based on the ADI values of pesticides, Korean MRL information and toxicological information of metabolite. The 24 pesticides were as follows: acibensolar-S-methyl, chlorfenapyr, chlorothalonil, cyantraniliprole, cyclaniliprole, cyflumetofen, dithiocarbamates, fenamidone, fenpyroximate, fluazifop-P-butyl, fluopicolide, flupyradifuron, fluxapyroxad, glyphosate, hexythiazox, isoprothiolane, isopyrazam, myclobutanil, penthiopyrad, propiconazole, spinetoram, spiromesifen, spirotetramat, trifloxystrobin. Furthermore, chlorfenapyr, chlorothalonil, dithiocarbamates and fenamidone may have considered a top priority for review due to greater toxicity of metabolite. This study could be of great use for improvement on risk assessment approaches in South Korea regarding pesticide residues in food commodities.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.123-123
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• 2017

기후변화의 영향으로 개발밀도가 높은 도시지역은 호우로 인한 피해가 지속적으로 증가하고 있다. 최근, 극한 호우에 의해 발생되는 도시침수의 피해를 저감하기 위해 시설물 대책에만 의존하기 보다는 지자체가 수립하는 공간계획을 통해 토지이용, 건축물 등을 아우르는 종합적인 예방전략 마련이 강조되고 있다. 하지만 지자체 도시계획 담당자가 기후변화를 고려해 방재대책을 마련하는데는 국가 차원의 표준화된 방법론의 부재, 침수해석을 위한 전문적 지식이 요구되는 등의 한계가 있다. 본 연구에서는 지자체가 도시계획에 실효성 있는 방재대책을 마련하는데 직접적으로 활용할 수 있는 도시침수에 대한 상세 위험도 주제도를 개발하고자 한다. 이를 위해, 우선적으로 중장기적인 측면에서 기후변화의 영향과 도시지역의 유출 특성을 고려해 방재계획을 수립할 수 있는 강우 시나리오 기준으로 지속시간 1시간에 대한 재현빈도 30년과 100년을 제시하였다. 기후변화의 영향을 고려한 강우 시나리오 기준에 따라 도시지역 내 내수 외수의 침수발생 원인을 고려해 침수심 지도를 생성하고자 한다. 이를 위해 범용적으로 적용할 수 있는 침수해석 모형인 HEC-RAS와 SWMM을 선정하고, 공간적 제약이 없이 폭 넓게 적용할 수 있도록 모형의 구축 절차를 간소화한 방법을 제안하였다. 간소화된 침수해석 모형 결과를 토대로 강우 시나리오별 침수심 지도를 제작하고, 강우 시나리오와 침수심을 기준으로 위험정도에 따라 Red zone, Orange zone, Yellow zone, Green zone으로 영향권을 설정하였다. 실질적으로 각 영향권에 적합한 도시계획 차원에서의 방재대책 수립이 가능하도록 노출특성과 취약성 분석을 실시하였다. 노출특성은 영향권에 노출된 토지이용면적(m2)과 거주인구수(명)로 평가하고 취약성은 영향권 내 취약한 건축물 수(지하 또는 노후 건축물), 보호대상시설물 수로 평가하였다. 침수 발생이 예상되는 영향권별 노출특성과 취약성 분석 결과를 토대로 위험이 높은 지역(Red zone)은 공간규모를 축소해 상세 위험도 공간정보 주제도를 개발하였다. 또한 위험도가 높은 지역은 작은 공간 단위로 노출특성과 취약성을 분석해 상세 위험도 주제도를 개발하였다. 본 연구에서 개발한 상세 위험도 공간정보는 지자체가 도시계획 수립단계에서 실질적인 방재대책을 강구하는데 활용할 수 있을 것으로 기대한다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.11
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• pp.1462-1467
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• 2018

A number of algorithms for improving the image quality of low light images have been studied using a single image or multiple exposure images. The low light image is low in contrast and has a large amount of noise, which limits the identification of information of the subject. This paper proposes the hardware design of algorithms that improve the quality of low light image using 2 multiple exposure images taken with a dual camera. The proposed hardware structure is designed in real time processing in a way that does not use frame memory and line memory using transfer function. The proposed hardware design has been designed using Verilog and validated in Modelsim. Finally, when the proposed algorithm is implemented on FPGA using xc7z045-2ffg900 as the target board, the maximum operating frequency is 167.617MHz. When the image size is 1920x1080, the total clock cycle time is 2,076,601 and can be processed in real time at 80.7fps.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.631-633
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• 2010

본 논문에서 제시하는 통합 관리 지능형 에이전트 기술은 개인정보보호 사고의 원인분석을 통해 도출된 요구기능을 통합 구현하는 기술이다. 본 기술은 PC 및 인터넷 이용자들의 개인정보 침해에 따른 경제적 피해를 줄이고, 안전한 인터넷 문화를 정착하여 인터넷 이용자들의 인터넷 경제활동 활성화에 기여할 뿐만 아니라, 개인정보 노출방지 등을 통해 명의도용 등의 사고를 예방하여 실물경제활동도 촉진하는 효과가 있다. 먼저, 피싱 파밍 등의 개인정보 침해에 대응한 상황인식 기반 피싱 파밍 자동분석 기술을 적용함으로써 인터넷 사이트를 통한 경제활동의 신뢰가 확보되어 인터넷 금융, 온라인 쇼핑몰 등의 인터넷 경제활동을 촉진하게 되며, 개인정보 노출에 따른 피해를 줄임으로써 다양한 형태의 명의도용 사고를 방지할 수 있다.

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.217-219
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• 2004

전자문서교환(EDI, Electronic Data Interchange)은 기업과 기업 간에 컴퓨터와 컴퓨터의 통신을 통하여 필요한 거래문서를 구조화된 형식으로 교환하여 업무를 처리하는 방식을 말한다. 이러한 전자문서의 유통은 절러 위험요소로부터 완전히 해방되지는 못한다. 본 연구에서는 향후 국내에서 발생 될 위협요소 중 우선적인 보호가 요구되는 것으로 메시지 노출로 인한 프라이버시 침해 및 중요 내용의 노출문제와 메시지 수정 문제 및 발신처 인증 문제. 그리고 수신자의 수신사실에 대한 부인을 위험요소로 선정하였다. 또한, 이를 막기 위한 보안서비스를 메시지 비밀보장. 무결성, 메시지 발신처 인증 및 수신내용 부인불능 등을 선정하여 이들의 구현방안을 제시하였다.