• Journal of Korean Society of Coastal and Ocean Engineers
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• v.34 no.6
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• pp.258-265
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• 2022

In Korea, the hydraulic model tests for measuring the wave overtopping have been almost conducted with no bottom slope or single slope condition in Korea. In this study, the bottom seabed for the coastal road area was fabricated at the wave flume and the wave overtopping was measured. The overtopping rate was also measured with the numerical modelling by OLAFoam. The measuring data were compared with EurOtop manual. It could be known the the influence of the foreslope in front of the vertical wall was significant and the these effects should be concerned when designing the coastal structures. And also it could be known that OLAFoam could be used to predict the wave overtopping rate for the complex bottom topography.

• KNOM Review
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• v.22 no.1
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• pp.11-19
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• 2019

As technology develops, the latest security threats on the network applied to users are increasing. By attacking industrial or corporate systems with malicious purposes, hackers cause many social problems such as confidential information leakage, cyber terrorism, infringement of information assets, and financial damage. Due to the complex and diversified threats, the current security personnel alone are not enough to detect and analyze all threats. In particular, the Supervisory Control And Data Acquisition (SCADA) used in industrial infrastructures that collect, analyze, and return static data 24 hours a day, 265 days a year, is very vulnerable to real-time security threats. This paper introduces security information and event management (SIEM), a powerful integrated security management system that can monitor the state of the system in real time and detect security threats. Next, we compare SIEM solutions from various companies with the open source SIEM (OSSIM) from AlienVault, which is distributed as an open source, and present cases using the OSSIM and how to utilize it.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.393-399
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• 2023

Upper limb amputees wear an upper limb prosthesis for both aesthetic purposes and functional necessity, and in particular, in the case of amputee with both hands, it is essential to wear a myoelectric prosthetic hand capable of gripping action. The prosthetic hand operated by the EMG signal of the remaining muscles is a public insurance benefit item of the Industrial Accident Compensation Insurance, and test method standards are needed to be developed for the safety of the user and the effectiveness of the product performance. In this study, we developed systems for measuring the gripping force of myoelectric hand prosthesis by a load cell and for durability test of the prosthesis over repeated use with a proximity sensor, and propose a test method standard. Since the international test method standard has not yet been established, it is expected that Korea will be able to play a leading role in this standardization field in the future.

• Korean Journal of Mineralogy and Petrology
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• v.36 no.4
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• pp.303-312
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• 2023

The determination of the oxidation states of metal elements in manganese nodules sheds light on the understanding of the formation mechanism of nodules, providing insights into the paleo-environmental conditions such as the redox potential of the aqueous system. This study aims to reveal the oxidation states and chemical bonding of manganese in the natural polymetallic nodules, utilizing conventional X-ray photoelectron spectroscopy (XPS). Specifically, shallow manganese nodules from the Siberian Arctic Sea, effectively recording mineralogical variations, were used in this study. Detailed analysis of XPS Mn 2p spectra showed changes in the manganese oxidation state from the center to the outer parts of the nodules. The central part of the nodules showed a higher Mn⁴⁺ content, approximately 67.9%, while the outermost part showed about 63% of Mn⁴⁺ due to an increase in the Mn³⁺+Mn²⁺. The decrease in the Mn oxidation state with the growth is consistent with the previously reported mineralogical variations from todorokite to birnessite with growth. Additionally, the O 1s spectra presented a predominance of Mn-O-H bonds in the outer layers compared to the center, suggesting hydration by water in the layered manganates of outer layers. The results of this study demonstrate that XPS can be directly applied to understand changes in paleo-environmental conditions such as the redox states during the growth of manganese nodules. Finally, future studies using high-resolution synchrotron-based XPS experiments could achieve details in oxidation states of manganese and trace metal elements.

• Journal of Korean Society of Forest Science
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• v.98 no.4
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• pp.479-490
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• 2009

This research was carried out to understand the actual condition of Forest Management Agency System, Cooperative Forest Program and People's Forest Program with Public Participation and to boost the program. To carry out a quantitative survey among selected 5 Regional Forest Service and 27 National Forest Office, we investigated the activity-awareness concepts of officers on Importance, Performance, and problems of program. As a results, the difference of understanding on National Forest Management System involved with the results of agreement achieved. Also most serious problem of Forest Management Agency System were the shortage of participation will and the limitation of security benefit. The prime reason for the program problem is lack of investment in People's Forest Program. The final results on survey of National Forest Management System with the Importance and Performance as followed. It indicated that I(Keep Up Good Work) have 5 Factors, II(Concentrate Here) have 2 Factors, III(Low Priority) have 6 Factors, and IV(Possible Overkill) have 2 Factors. Base on above investigation, we finally suggest that new organization exclusive responsible for the improvement of management and encouragement of Build Transfer Operate.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.4 no.4
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• pp.378-387
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• 1994

To improve the properties of $PbTiO_3$ thin films successfully grown by thermal diffusion of 3 component layers of $Ti0_2/Pb/TiO_2(900{\AA}/900{\AA}/900{\AA})$ in preceding research, 3, 5, 7, 9, and 11 multilayer structures $(TiO_2/Pb/.../Tio_2)$ with thinner component layer of $200~300 {\AA}$ thick were deposited on Si substrate by RF sputtering, which were followed by RTA to form $PbTiO_3$ thin films. As a result, $PbTiO_3$ single phase was formed above $500^{\circ}C$. When the thickness of component layer reduced and the number of component layers increased, suppression of Pb-silicate and voids formation resulted in relatively sharp interfaces and the film composition became more homogeneous. Relative dielectric constants in MIM structure were independent of the annealing condition, but they increased with increasing thickness of the $PbTiO_3$ thin films. The maximum breakdown field in MIS structure reached 150kV/cm.

• Journal of the Korean earth science society
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• v.31 no.6
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• pp.584-599
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• 2010

The variation of atmospheric conditions including subrefraction, normal refraction, superrefraction, and ducting is an important factor that affects the quality of radar data by controling the propagation of radar beams. The occurrence frequency of the conditions is statistically analyzed using the atmospheric soundings from seven radiosonde stations in South Korea over two years. The occurrence of superrefraction and ducting at Baengnyeongdo is significantly higher than the others. Osan and Kwangju show significant variation in time. Among the different duct conditions, the surface duct is dominant at most stations except for Gosan. The elevated duct is dominant at Heuksando and Gosan. Duct is more frequent in summer than in winter at all stations. Baengnyeongdo shows the most frequent duct in spring, fall, and winter while Pohang had the highest frequency in summer. Osan and Kwangju show least duct during all seasons. The difference of variation of monthly duct occurrence between 00 UTC and 12 UTC is insignificant at all stations except for Osan and Kwangju. Kwangju, Heuksando and Gosan show relatively low frequency of duct with the monthly maximum barely reaching 60%. The highest number of elevation angles that are affected by duct was four at Osungsan radar (KSN). The maximum elevation angle is around $1.0^{\circ}$ at all stations and Jindo radar (JNI) shows the maximum value of $1.2^{\circ}$.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.7
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• pp.868-876
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• 2014

The objective of this study is focused on the analyzing combustion, carbon monoxide and hydrocarbon emission characteristics of marine diesel oil, utilized for naval propulsion engine, with varying pre-post injection timing of an optically accessible single cylinder engine. And also the combustion process is analyzed by means of a high speed camera visualization. On the result of retarding pre-injection timing toward main injection timing, the mean effective pressure and maximum pressure of combustion chamber are increased; however, the heat release rate is decreased. Furthermore, the emission rates of carbon monoxide and hydrocarbon are reduced in this case. In hence, when a post-injection timing is advanced, the mean effective pressure and maximum pressure are increased, because the combustion has been performed under the high temperature and high pressurized environment during main injection time, and the emission rates of carbon monoxide and hydrocarbon are increased. From the experimental results, it considered that retarding of pre-injection timing affects to shorten the ignition delay of main injection clearly, and to raise the flame intensity comparing to the advanced state. The ignition delay during post-injection is not appeared at any post-injection time, but the flame intensity has been weakened gradually according to the retarding of post-injection timing.

• The Korean Journal of Malacology
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• v.30 no.1
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• pp.1-8
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• 2014

Oxygen isotope analysis was carried out on a oyster (Crassostrea gigas) from the neolithic age Gagok-ri shell midden site, Dangjin, Korea to determine the seasonality of shellfish gathering and site occupation. Isotope samples were taken from the hinge section of the left valve of the oyster. The isotope values of the shell range from -2.02‰ to -6.05‰ vs PDB. The isotope profile shows a seasonal temperature cycle, providing information related to seasonality of shellfish gathering. The isotope values towards the edge of the hinge are gradually increasing, suggesting progressively cooling and a fall period of shell gathering and site occupation. The result shows that the oxygen isotope analysis using oyster shell hinges can be used for archaeological seasonality studies.

• 한국지구과학회:학술대회논문집
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• 2006.02a
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• pp.239-244
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• 2006

충청북도 영동 지역에 분포하는 영동층군은 옥천변성대에 있는 소규모 퇴적분지중의 하나이다. 영동층군의 지질과 고생물에 관한 연구는 옥천변성대의 조구조운동과 관련한 퇴적분지 발달 규명과 아울러 경상분지와의 상호대비가 가능케 함으로써 이 시기의 한반도의 지질을 이해하는데 있어 매우 중요한 정보를 제공해 줄 수 있다(김규봉 등, 1986). 영동층군의 층서고생물학적 연구는 김규봉 등(1986), 전희영 등(1993), 최성자 등(1995)등의 연구가 있다. Shimamura (1927)는 영동층군에서 케이로레피드과(Cherolepidiaceae)에 속하는 식물화석의 산출을 처음 보고하였다. 이후 전희영 등(1993), 최성자 등(1995)이 영동층군에서 케이로레피드과에 속하는 식물화석을 다시 보고함으로써 영동층군에서 식물화석이 많이 산출될 가능성이 확인되었다. 본 연구에서는 식물화석의 연구에 중점을 두고 야외지질조사를 통하여 영동층군의 기존 화석산지와 새로운 화석산지로부터 많은 식물 화석을 채집하였다. 식물 화석은 모두 인상화석으로 보존되었으며 세일층의 층리면에 평행하게 밀집된 상태로 나타나지만 대부분 파편상으로 나타난다. 식물화석은 고환경이나 고생태에 대한 중요한 단서를 제공하고 과거의 기후를 알려주는 중요한 지시자로 사용되고 있다. 특히 케이로레피드과의 식물은 백악기의 대표적인 고기후의 지시자로서 잘 알려져 있다. 케이로레피드과의 식물은 분류상 구과류에 속하며 백악기에 걸쳐 세계적인 분포를 보이고 있는 화석이다. 본 연구는 영동층군에서 산출된 구과류 화석을 대상으로 고생물학적 연구를 수행하여 산출화석의 특징을 기재하고 체계적으로 분류함으로써 산출화석의 고식물학적 의미를 밝히고자 하였다. 또한 산출 화석의 특징과 지질학적 특징을 통해 중생대 백악기 영동지역의 고기후를 해석함으로써 고기후적 및 고생태학적 의미를 연구해 보고자 하였다.에서는 시스템 등급에 영향을 준다. 향후에는 더욱 더 다양한 상호의존 모델들이 정량화될 필요성이 있다고 본다. 진행하였다. 줄여서 보다 더 정확하고, 지능적인 규칙구성요소 추출 방법론을 제시하고 구현하여 지식관리자의 규칙습득에 대한 부담을 줄여 주고자 한다. 도움을 받을 수 있게 되었다.을 거치도록 되어있다. 교통주제도는 국가의 교통정책결정과 관련분야의 기초자료로서 다양하게 활용되고 있으며, 특히 ITS 노드/링크 기본지도로 활용되는 등 교통 분야의 중요한 지리정보로서 구축되고 있다..20{\pm}0.37L$, 72시간에 $1.33{\pm}0.33L$로 유의한 차이를 보였으므로(F=6.153, P=0.004), 술 후 폐환기능 회복에 효과가 있다. 4) 실험군과 대조군의 수술 후 노력성 폐활량은 수술 후 72시간에서 실험군이 $1.90{\pm}0.61L$, 대조군이 $1.51{\pm}0.38L$로 유의한 차이를 보였다(t=2.620, P=0.013). 5) 실험군과 대조군의 수술 후 일초 노력성 호기량은 수술 후 24시간에서 $1.33{\pm}0.56L,\;1.00{\ge}0.28L$로 유의한 차이를 보였고(t=2.530, P=0.017), 술 후 72시간에서 $1.72{\pm}0.65L,\;1.33{\pm}0.3L$로 유의한 차이를 보였다(t=2.540, P=0.016). 6) 대상자의 술 후 폐환기능에 영향을 미치는 요인은 성별로 나타났다. 이에 따른 폐환기능의 차이를 보면, 실험군의 술 후 노력성 폐활량이 48시간에 남자($1.78{\pm}0.61L$)가 여자($1.27{\pm}0.45L$)보다 더 높게 나타났으며 (t=2.170, P=0.042), 72시간에도 역시 남자($2.1