• Proceedings of the Korean Society of Computer Information Conference
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• 2020.01a
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• pp.37-39
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• 2020

인터넷 상에서의 허위정보 생산과 유통은 주로 가짜 뉴스를 통하여 이루어진다. 과거에는 신문이나 공중파 TV등 뉴스 기사의 생산과 유통이 매우 제한적이었지만 지금은 인터넷의 발달로 누구나 쉽게 뉴스를 생산하고 유통할 수 있다. 뉴스 생산의 용이성은 정보 공유의 즉각성과 수월성이라는 장점을 제공하지만 반대로 불확실한 뉴스 남발로 인한 정보의 신뢰성 하락과 선량한 피해자를 양산하는 단점 또한 존재한다. 이는 가짜 뉴스가 사회적 문제로 대두되고 있는 이유이다. 에이전트나 스파이더 등의 소프트웨어를 통해 인터넷으로 급속도로 전파되는 가짜 뉴스를 전통 방식인 소수의 전문가가 수동으로 잡아내는 것은 불가능하다. 이에 기술발달로 잡아내기 힘들어진 가짜뉴스에 대해, 역으로 발달된 기술을 활용하여 잡아내려는 시도가 늘어나고 있다. 본 논문에서는 가짜뉴스를 판별하는 다양한 기법들을 탐색하고 해결방안을 제시하고자 한다.

• Geotechnical Engineering
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• v.13 no.2
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• pp.77-90
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• 1997

A resonable and economical method which can predict permeability of rock mass in underground is needed to overcome the uncertainty of groundwater behavior. For this par pose, one prediction method of permeability has been studied. The artificial neural networks model using error back propagation algorithm, . one of the teaching techniques, is utilized for this purpose. In order to verify the applicability of this model, in-situ permeability results are simulated. The simulation results show the potentiality of utilizing the neural networks for effective permeability prediction of rock mass.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.05a
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• pp.68-71
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• 2018

In this paper, we propose a synchronization protocol for underwater acoustic networks which aims to minimize the effects of long propagation delay and uncertain delay variations and employs packet train scheme with considering low data rate. The proposed protocol uses an one-way delay measurement method by transmitting consecutive packets and acquires synchronization only considering propagation delay variations by calculating packet arrival time differences. We perform simulations under various network conditions, such as node mobility, time interval for packet transmission, network range, and elapsed time after synchronizing. The simulation results shows the superiority of our protocol, compared with a previously proposed protocol.

• International Commerce and Information Review
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• v.15 no.4
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• pp.391-418
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• 2013

The development of web 2.0 technologies created the popularization of social media. People use social media for information communication with many purposes. Under such an environment, this paper examines the acceptance of word-of-mouth information dissemination through social media. The determinants of acceptance and the effect of acceptance on purchase intention as the result of information on social media pertaining to overseas tourism are researched in detail. The consumer choice for international travel involves a decision making with high uncertainty and thus people are using the word of mouth information strongly. Empirical analysis using SPSS, AMOS analysis software was performed on sample data consisting of 385 collected surveys. This paper shows the neutrality of eWOM, the professionalism of senders, and that the practicability of eWOM significantly affects the acceptance of the information. In addition, the acceptance of eWOM information has a significant effect on the spread of eWOM and customers' purchase intention. The paper shows that the practicability of information and the professionalism of word-of-mouth information should be improved.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.1384-1388
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• 2009

래스터 기반 DEM 모델을 이용한 수문지형인자의 산정은 DEM의 해상도(셀크기)에 영향을 받으며, 이러한 DEM의 해상도에 따른 불확실성은 강우-유출모델의 결과에 전파되어 모델의 모의결과에 오차를 발생시키는 원인이 된다. 또한 흐름경로의 결정은 수문모델링에서 DEM으로부터 수계를 형성하고 유역을 생성 및 분할하는데 있어 결정적인 역할을 하며, 각 셀의 경사는 흐름방향을 결정하고 흐름길이는 흐름경로를 따라 측정된 거리로서 결정된다. 이러한 모든 일련의 과정들은 셀간의 연산을 통해 이루어지며, 이러한 점에서 DEM의 해상도에 따른 DEM 처리연산 및 수문지형인자의 변동성은 중요한 고려사항이라 할 수 있다. DEM의 해상도에 따른 영향을 규명하기 위해서는 주요 수문지형인자를 대상으로 DEM의 해상도에 따른 민감도를 분석하는 것이 일반적이며, 따라서 본 연구에서는 위천, 황강 및 금호강 유역에 대해 DEM의 셀크기에 따른 유역면적, 유로연장과 최원유로연장, 유역평균경사와 같은 수문지형인자의 변동성을 분석하였다. 셀크기가 증가함에 따라 유로연장 및 최원유로연장이 감소하는 추세는 보이고 있지만 셀크기의 증가로 인해 반드시 흐름길이 및 유로연장이 감소 또는 증가되는 것은 아니며, 더 많은 유역에 대한 적용을 통해 유로연장에 대한 변동을 규명할 필요가 있을 것으로 판단된다. 또한 유역평균경사는 대체로 셀크기 $10\sim30m$에서 가장 큰 감소를 보이고 있으며, 셀크기 30m 이상에서는 감소크기가 점차 완만하게 나타난다. 그리고 셀크기가 증가할수록 유역평균경사에 대한 누가빈도곡선의 기울기는 점차 급해지고 누가빈도가 증가할수로 각 셀크기간의 유역평균경사의 감소에 큰 영향을 미침을 알 수 있다. 이는 비록 유역평균경사에 대한 누가빈도분포의 추세가 모든 해상도에 대해 유사하게 나타나고 있지만 급경사부에 대해서는 데이터 축약으로 인해 유역평균경사에 있어 상당한 감소를 발생시킬 수 있기 때문이라 판단된다.

• Journal of the Korean earth science society
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• v.41 no.5
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• pp.478-489
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• 2020

This study presents an analysis of infrasonic signals from two accidental explosions in Gwangyang city, Jeonnam Province, Korea, on December 24, 2019, recorded at 12 infrasound stations located 151-435 km away. Infrasound propagation refracted at an altitude of ~40 km owing to higher stratospheric wind in the NNW direction, resulting in favorable detection at stations in that direction. However, tropospheric phases were observed at stations located in the NE and E directions from the explosion site because of the strong west wind jet formed at ~10 km. The transmission losses on the propagation path were calculated using the effective sound velocity structure and parabolic equation modeling. Based on the losses, the observed signal amplitudes were corrected, and overpressures were estimated at the reference distance. From the overpressures, the source energy was evaluated through the overpressure-explosive charge relationship. The two explosions were found to have energies equivalent to 14 and 65 kg TNT, respectively. At the first explosion, a flying fragment forced by an explosive shock wave was observed in the air. The energy causing the flying fragment was estimated to be equivalent to 49 kg or less of TNT, obtained from the relationship between the fragment motion and overpressure. Our infrasound propagation modeling is available to constrain the source energy for remote explosions. To enhance the confidence in energy estimations, further studies are required to reflect the uncertainty of the atmospheric structure models on the estimations and to verify the relationships by various ground truth explosions.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.36 no.2
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• pp.80-86
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• 2024

Large-scale earthquakes are occurring globally, especially in the South Asian crust, which is experiencing a state of tension in the aftermath of the 2011 East Japan Earthquake. Uncertainty and fear regarding the possibility of further seismic activity in the near future have been on the rise in the region. The National Disaster Management Research Institute has previously studied and analyzed the overflow characteristics of a tsunami and the rate of flood forecasting through tsunami numerical simulations of the East Sea of South Korea. However, there is currently a significant lack of research on the Southern Coast tsunamis compared to the East Coast. On the Southern Coast, the tidal difference is between 1~4 m, and the impact of the tides is hard to ignore. Therefore, it is necessary to analyze the impact of the tide propagation characteristics on the tsunami. Occurrence regions that may cradle tsunamis that affect the southern coast region are the Ryukyu Island and Nankai Trough, which are active seafloor fault zones. The Southern Coast has not experienced direct damage from tsunamis before, but since the possibility is always present, further research is required to prepare precautionary measures in the face of a potential event. Therefore, this study numerically simulated a hypothetical tsunami scenario that could impact the southern coast of South Korea. In addition, the tidal wave propagation characteristics that emerge at the shore due to tide and tsunami interactions will be analyzed. This study will be used to prepare for tsunamis that might occur on the southern coast through tsunami hazard and risk analysis.

• Nuclear Engineering and Technology
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• v.21 no.1
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• pp.18-31
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• 1989

To analyze the impact of air pollution control on electricity generation cost, a computer program was developed. POGEN calculates levelized discounted power generation cost including additional air pollution control cost for coal power plant. Pollution subprogram calculates total capital and variable costs using governing equations for flue gas control. The costs are used as additional input for levelized discounted power generation cost subprogram. Pollution output for Rue Gas Desulphurization direct cost was verified using published cost data of well experienced industrialized countries. The power generation costs for the year 2001 were estimated by POGEN for three different regulatory scenarios imposed on coal power plant, and by levelized discounted power generation cost subprogram for nuclear power. Because of uncertainty expected in input variables for future plants, sensitivity and uncertainty analysis were made to check the importance and uncertainty propagation of the input variables using Latin Hypercube Sampling and Multiple Least Square method. Most sensitive parameter for levelized discounted power generation cost is discount rate for both nuclear and coal. The control cost for flue gas alone reaches additional 9-11 mills/kWh with standard deviation less than 1.3 mills/kWh. This cost will be nearly 20% of power generation cost and 40% of one GW capacity coal power plant investment cost. With 90% confidence, the generation cost of nuclear power plant will be 32.6-51.9 mills/kWh, and for the coal power plant it will be 45.5-50.5 mills/kWh. Nuclear is favorable with 95% confidence under stringent future regulatory requirement in Korea.

• The Journal of Information Systems
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• v.18 no.4
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• pp.19-40
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• 2009

승자독식(Winner Takes All)이라는 글로벌 경쟁원리로 인해 세계 주요 국가들 사이에 R&D 경쟁이 갈수록 치열해지고 있다. 이에 우리나라에서도 R&D 지원 확대 및 다양한 정책기획 활동 등이 전개되었다. 이러한 노력에도 불구하구 국가 차원에서 기획 및 정책조정이 효과적으로 추진되지 못하고 있으며, 국가연구개발사업 차원에서는 "기획의 양척 과다와 질적 부실"이라는 비판이 제기되고 있다. 반면에 기술 융복합화의 가속화 등 R&D 환경의 불확실성은 더욱 높아졌으며 국가연구개발사업의 규모 증가와 함께 연구기획의 복잡성은 더욱 더 높아졌다. 최근에는 국가 차원의 비전수립과 중장기 정책기획에 기초하여 사업기획과 과제기획을 연계 수행하는 등 기획을 통해 과제를 도출하는 하향식 접근이 강조되면서 기획의 중요성은 더욱 커졌다. 최근 연구기획의 새로운 기법으로서 정보분석 방법론(Information Analysis Method)이 대두되고 있다. 국가연구개발사업의 효율적 기획을 위하여 기존 기술기획 위원회(Peer Review) 방식 외에 정보분석 방법론을 통한 보완이 필요하다. 본고의 목적 크게 두 가지로 설명할 수 있다. 첫째, 현재 진행되고 있는 연구기획 및 연구기획 방법론으로 기장 많이 활용되고 있는 전문가 위원회의 한계를 제시하였다. 둘째, 최근 대두되고 있는 정보분석 방법론과 정보분석 시스템 구축, 그리고 이를 활용한 10대 기술(반도체, 디스플레이, 디지털 망원전파, 이동통신, BcN, 차세대 컴퓨팅, SW솔류션, 디지털콘텐츠, 임베디드 SW, 지식정보보안)에 대한 유망기술 발굴 실증분석을 실시하였다.

• Fire Science and Engineering
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• v.27 no.2
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• pp.25-30
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• 2013

'Heaundae Woosin Building' fire was the case that a fire breaking out on the $4^{th}$ floor spread out the $38^{th}$ floor which is a top story and the penthouse was destroyed by fire. After this fire, the fire safety for high rise buildings has been on the rise and several new laws and regulations related in the buildings were created. The study is to analyze Heaundae officetel building case using FDS which is one of the CFD programs for fire. The methodology of this study is to analyze the case comparing with fire spread and route from a virtual fire simulation and related articles and a video clip of actual scene fire. This study shows that a fire spreading on top of levels spent approximately 30 minutes and, which is similar to the actual fire case. Also the pattern of spread has similarity with the case. However, even if the actual fire case shows the fire pattern was "V shape", the smoke-view presents the fire dose not spread horizontally as much as the real fire case. The result shows uncertainty of the modeling based on many grids and a limitation of putting interior finish input sources and the direction of the wind might cause the difference. Also, to analyze factors influencing on a vertical fire, another fire modeling is performed by in condition of modeling environment considering concrete interior finish between buildings and no wind. The result presents the fire spread in smoke-view does not spread vertically as much as the actual case.