• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.153-156
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• 2005

현재 육상과 해상간의 통신은 Inmarsat 단말기를 이용하여 전화, 텔렉스, 팩스, 전자메일(E-mail) 및 데이터 통신을 한다. 기존 전자메일 프로그램은 비싼 통신요금과 저속의 위성통신 환경에서 최대한 통신비용을 줄이기 위한 목적으로 개발되었다. 그리고 팩스를 이용하는 경우는 관련문서를 출력 후, 송신하기 때문에 시간과 비용이 낭비된다. 이에 현재 많은 나라에서 Inmarsat을 이용한 육상과 선박간의 서로 다른 네트워크 상의 정보를 공유할 수 있는 방법을 모색하고 있다. 따라서 본 논문에서는 기존의 육상과 해상간의 전자메일 시스템과 팩스 기능을 통합한 육상과 해상을 모두 지원하는 인터넷 기반의 팩스 서비스 시스템에 관한 연구이다. 이를 위하여 기존 전자메일 시스템과 공중전화망(PSTN : Public Switched Telephone Network)을 연결하는 하드웨어적인 모듈을 설계하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.80-81
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• 2022

자율운항선박 원격제어시스템의 실증을 위하여 기존 육상제어센터에서 선박을 제어하는 것은 현재 개발중인 시스템으로 인한 선박의 안전성 확보에 어려움이 있다. 이에 본 연구에서는 원격제어시스템을 시험하기 위하여 선박에서 육상제어센터로 명령을 주어 선박과 육상제어센터 내 모사장치를 통한 원격제어시스템을 테스트하였다. 본선의 통신네트워크(LTE, VSAT)을 통해 선장의 명령으로 선박의 육상제어센터의 모사장치를 제어하였다. 1차 소각도를 이용한 원격제어시험과 2차 Zig-zag 테스트를 실시하여, 개별 시스템의 문제점을 식별하고, 개별 시스템간의 통합을 위한 방안을 제시하였다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2021.11a
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• pp.219-220
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• 2021

자율운항 선박 지원 6종 서비스는 인공지능 센서 기반 선박 접/이안 및 계류지원 서비스, 화물 양적하 및 선박 입출항 지원, 선박과 터미널 간 실시간 정보 교류를 통한 운항정보 동기화, PSC 점검지원, 선박의 주요 기기를 육상 시범운영센터에서 표출하는 상태모니터링 지원 서비스, 해양사고 발생 시 신속한 조치을 위한 사고 대응지원 서비스로 구성되어 있다. 이 연구에서는 개발되는 6종 서비스 성능검증이 원활히 수행될 수 있도록 육상과 실선박에 설치되어야 하는 장비, 선박과 육상서비스 센터의 데이터 전송을 위한 네트워크 인프라 그리고 종합 상황실 역할의 육상 시범운영센터를 구축하여 안전운항을 위해 6종서비스가 이루어 져야한다.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.2
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• pp.96-109
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• 2021

Since terrestrial input plays a major role in coastal primary production, an understanding of land-ocean coupling (LOC) is key to understand coastal ecological changes. In this study, the LOC has been classified into three stages (i.e., the baseflow, plume event and residual flow). In order to characterize its pattern in Nakdong River estuary, multi-platform data were obtained from remote sensing (geostationary ocean color image (GOCI)), in-situ measurement (marine environment information system (MEIS)), on-site measurement (discharge data and meteorological data). The MEIS data were grouped into three stages of LOC using principal component analysis (PCA), and the LOC (2013 ~ 2018) was examined at each stage using multi-platform data. In the Nakdong River estuary, the maximum value of chlorophyll-a (chl-a) was unexpectedly appeared during the plume event. It is assumed that there was no significant increase in turbidity, expected during the typical plume event, together with the weak flushing effect, caused the enhanced phytoplankton growth. Compared with other estuaries, LOC is common in estuaries affected by freshwater inflow, but LOC has different pattern depending on the size of the plume. While estuaries that form small plumes of about 10 km (low freshwater discharge and weak flushing effect) observed high chl-a in the plume event because the phytoplankton can response to the increased nutrient more rapidly. estuaries that form large plumes of more than 100 km est (high freshwater discharge and strong flushing effect) follow the typical LOC pattern conceptualized in this study (high chl-a in the residual flow).

• Journal of the Korea Convergence Society
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• v.11 no.4
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• pp.311-321
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• 2020

The purpose of this study was to analyze the recognition of secondary pre-physical education teachers' recognition for the learning athletics using Q methodology. P-sample was composed of 28 pre-secondary P·E teachers. The selected Q samples were arranged in the normal distribution form. The collected data were analyzed by factor analysis through varimax rotation using QUANL PC program. This study found four types of recognition on learning athletics. Type I is defined 'the type of recognition for education value.' Type II is defined 'the type of emphasizing assistant activities.' Type III is defined 'the type of an appeal difficulty to learn athletics skill.' Type IV is defined 'the type of emphasizing the basic movement value.' Based of the results of this study, the implications and direction to future research on athletics activities are suggested.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.9
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• pp.1833-1839
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• 2011

In this study, Global Gravitational Model EGM2008, EGM96 and 16,786 gravity points measured on land were compared and analyzed. On the assumption that land gravity data is most accurate, the correlation coefficient, differences, MSE and difference variance along the height were computed between land gravity data and EGM2008, EG96. The correlation coefficient, land gravity data and EGM2008, was computed most largely with 0.824 and the correlation coefficient with EGM96 was computed with 0.538. The standard deviation of differences between land gravity and EGM2008, EGM96 were 13.196 magl, 18.685 mgal respectively. Also the difference variance scope of EGM2008 was smaller than EGM96. There was no large variance of free-air anomaly differences between land gravity data and EGM2008 along the height however free-air anomaly differences with EGM96 varied along the height changes. Consequently EGM2008 nicely expresses Korea gravity field more than EGM96.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.2B
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• pp.175-185
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• 2011

This study investigates tsunami force acting on a group of onshore structures numerically by using three-dimensional one-field model for immiscible multi-phase flows, which is based on Navier-Stokes solver. In particular, we studied on the characteristics of tsunami with respect to the arrangement of onshore structures and the distance from seawall trough numerical experiments. For validation of the numerical method used in this study to calculate tsunami force, numerical results for tsunami force on the structures in coastal area are compared with available experimental data. Furthermore, a detail study on the efficiency of the numerical method is performed for the estimation of tsunami force based on the hydrostatic and hydrodynamic methods in which the numerical results are used. The obtained results are compared to the previous experimental one and design criteria. Considering both experimental results and numerical analysis results, semi-empirical formula by regression analysis is proposed. As a result, it was confirmed that the numerical analysis is effective to estimate on tsunami force acting on onshore structures.

• Journal of Digital Convergence
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• v.17 no.5
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• pp.391-398
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• 2019

This study aimed to investigate the factors that influence the attitude toward doping and to provide useful information for developing a doping prevention program suitable for Korean athletic players. One hundred and seventy-two players who enrolled in Korea Association of Athletics Federations were participated in this study and they filled in the questionnaire about demographic factors, information on doping, perfectionism, and perceived motivational climate. Collected data were analyzed by using stepwise multiple linear regression for exploring the main factor that affect the attitude toward doping depending on field and track events. All adult players have more permissive attitude toward doping than adolescents. In track event, while players who are sensitive to coach's criticism have more permissive attitude toward doping, players who focused on personal standards have more repressive attitude toward it. These results would be useful to develop anti-doping strategy for Korean field and track players.

• Journal of Digital Convergence
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• v.19 no.11
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• pp.555-564
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• 2021

This study aims to examine the relationship between the expertise of track and field coaches, the team atmosphere, and athletic satisfaction in elite sports. To achieve this research purpose, data were collected using questionnaires from 221 student athletes from junior high to university students registered with the Korea Association of Athletics Federation in 2021 and collected using Google online questionnaires in consideration of the pandemic situation. For data processing, frequency analysis, exploratory factor analysis, reliability analysis, correlation analysis, and multiple regression analysis were performed using the statistical program SPSS 22.0, and the following conclusions were drawn. First, it was found that the expertise of the athletics coaches had a positive (+) effect on the team atmosphere. Second, among the sub-factors of athletics coach expertise, only athlete management was found to have a negative (-) effect on daily life satisfaction, a sub-factor of athletic satisfaction. Third, it was found that among the sub-factors of the team atmosphere, only role characteristics and leader characteristics had a positive (+) effect on social approval satisfaction, a sub-factor of athletic satisfaction.

• Geophysics and Geophysical Exploration
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• v.25 no.1
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• pp.1-13
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• 2022

For surveying shallow gas reservoirs in the Pohang basin, we proposed a seismic exploration method applicable to the transition zone in which land and marine areas are connected. We designed the seismic acquisition geometry considering both environments. We installed land nodal receivers on the ground and employed vibroseis and airgun sources in both land and marine areas. For seismic exploration in the transition zone, specific acquisition and processing techniques are required to ensure precise matching of reflectors at the boundary between the onshore and offshore regions. To enhance the continuity of reflection events on the seismic section, we performed amplitude and phase corrections with respect to the source types and applied a static correction. Following these processing steps, we obtained a seismic section showing connected reflectors around the boundary in the transition zone. We anticipate that our proposed seismic exploration method can also be used for fault detection in the transition zone.