• Journal of Environmental Health Sciences
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• v.37 no.3
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• pp.226-233
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• 2011

Exactly 25 years after the Chernobyl nuclear disaster, 11th of March 2011 the Fukushima nuclear accident occurred in Japan and was ranked at level 7 same to the Chernobyl. A Korean and Japanese joint civil survey was conducted around Fukushima on April 13-17. The radiation survey data clearly shows a large hotspot area between 20 km and 50 km radius north and west direction from the accident reactors, with the highest radiation recorded being 55.64 ${\mu}Sv/hr$ in the air, 99.89 ${\mu}Sv/hr$ in the surface air, and 36.16 ${\mu}Sv/hr$ in a car, respectively. 3.65 ${\mu}Sv/hr$ in the air and 6.89 ${\mu}Sv/hr$ in the surface air were detected at the playground of an elementary school in Fukushima City. Spring came with full cherry blossoms in Fukushima, but it was silent spring of radiation contamination. Interviews with Fukushima nuclear refugees reveal serious problems about Japanese nuclear safety systems, such as there was no practical evacuation drill within 1-10 km and no plan at all for 10-30 km areas. Several reforms items for Korean nuclear safety system can be suggested: minimization of accident damage, clear separation of regulatory and safety bureaus with a new and independent administrating agency, community participation and agreement regarding the safety system and levels, which is the major concern of 80% Korean. To tackle threats of nuclear disaster in neighboring nations like China, a new position entitled 'Ambassador for nuclear safety diplomacy' is highly necessary. The nuclear safety of Korea should no longer be the monopoly of those nuclear engineers and limited technocrats criticized as a 'nuclear mafia'.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.6
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• pp.157-163
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• 2018

This study is aimed at controlling the fiber orientation and improve the fiber distribution in fiber-reinforced cement composites using blades that can be placed inside the existing nozzles. To optimize the blade parameters, multi-physics finite element analysis was performed that could account for the flow of the cementitious matrix material, the movement of the entrained fibers, and the interactions with the nozzle. As a result, this study defined the blade distance, length, and position as a function of the fiber length to be used in the field. The blades with a distance from 1.2 to 2.4 times the fiber length and length from 4 to 8 times the fiber length, as well as located at below 14 times the fzfiber length from the nozzle exit maintained the fiber orientation angle less than $5^{\circ}$. In addition, the blade-type nozzle proposed in the study can be attachable and detachable to the conventional casting equipment, and thus it can provide the usability and convenience in practical applications.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.11
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• pp.1168-1179
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• 2006

The validity of an unsteady two-dimensional(2-D) numerical hydrodynamic and pollutant dispersion model(2DNHPDM) was evaluated using the data obtained from I-sa streams in Sooncheon, Chonnam, during rain-fall run-off. Field observations was conducted for 35 hours during the 10 hours rainfall event on 7th May 2005. The water level, 2-D velocity, flow field, and COD at seven points selected along the river were measured at intervals of one hour. The model was applied to describe two-dimensional movement of dissolved pollutants in meandering non-uniform river. Major physical processes affecting the lateral and horizontal mixing of the river flow were simulated. The model was proved effective in describing the hydrodynamics and dispersion of the river pollutants from its major tributaries as well as non-point sources.

• Korean Journal of Geomatics
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• v.2 no.1
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• pp.57-64
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• 2002

Measuring the depth of water is very important in ensuring the protection and safety of seaside. There are many difficulties in making the contour bathymetric map, and contour line due to the limitation of continuous measurement of water depth and collimation with the conventional measuring and positioning methods. But the real-time kinematic GPS (RTK GPS) positioning using a carrier phase enables us to decide a precise position without breaking a signal even under the condition of a moving environment. It is also possible to obtain an accurate depth of water in real time with a fathometer through the measuring of time delay between sending and receiving epochs. This research aims at investigation of accuracy potential of RTK GPS in combination with Echo Sounder(E/S) for the coastal mapping. Apart from this purpose, the accuracy of ambiguity resolution with the OTF(On the Fly) method was tested with respect to the initialization time. The result shows that the accuracy is better than 1cm with 5-minute initialization in the distance of 10km baseline. The seaside topography was measured by the RTK GPS only, on the other hand the seafloor topography was surveyed in combination of RTK GPS and E/S. Comparing to the volume of seaside measured by RTK GPS and digital topographical map, the difference of only 2 % was achieved. This indicates that the coastal mapping with RTK GPS is successfully conducted. In addition it is also demonstrated that the 3-dimensional perspective model resulted from the undersea topography measured by RTK GPS and E/S is very close to that from the digital map. Through this study, it was verified that RTK GPS is to be very useful method in the analysis of coastal morphology owing to its capability of getting the precise DTM for the using of harbor reclamation, dredging, and the estimation of soil movement in a river.

• Land and Housing Review
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• v.12 no.3
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• pp.97-108
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• 2021

In bridge abutment structures, lateral squeeze due to lateral stress of embankment placement and thermal movement of the bridge structure leads to failure of approach slabs, girders, and bridge bearings. Recently, GRS (Geosynthetic-Reinforced Soil) integral bridge has been proposed as a new countermeasure. The GRS integral bridge is a combining structure of a GRS retaining wall and an integral abutment bridge. In this study, numerical analyses which considered construction sequences and earthquake loading conditions are performed to compare the behaviors of conventional PSC (Pre-Stressed Concrete) girder bridge, traditional GRS integral bridge structure and GRS integral bridge with bracket structures (newly developed LH-type GRS integral bridge). The analysis results show that the GRS integral bridge with bracket structures is most stable compared with the others in an aspect of stress concentration and deformation on foundation ground including differential settlements between abutment and backfill. Furthermore, the GRS integral bridge with/without bracket structures was found to show the best performance in terms of seismic stability.

• Ocean policy research
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• v.33 no.2
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• pp.57-82
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• 2018

This study aimed to review the reorganization of fisheries and the future tasks in accordance with the establishment of new fishery order in the Northeast Asian Seas. As the United Nations Convention on the Law of the Sea, which recognized the sovereign rights of Coastal States in a 200-nautical mile exclusive economic zone (EEZ), entered into force in 1994, the three countries of Korea, China and Japan ratified the United Nations Convention on the Law of the Sea in 1996 and started negotiations to establish a new fishery order consistent with the EEZ system. However, a conflict of interest occurred because of differences in fisheries between countries, negotiations many times have proceeded, resulting in the signing of fishery agreement between China and Japan in 1997, Korea and Japan in 1998, and Korea and China in 2000. Each fishery arrangement consists of a dual system of EEZ and provisional waters (middle waters, provisional waters). The two countries are engaged in mutual fishing based on coastal states in EEZ, and in the fishing operation under the principle of flag state in provisional waters. There are overlapping or ambiguous jurisdictions in the intermediate waters and provisional waters that are jointly available to both fisheries. The presence of these seas is a challenge to the establishment of a reasonable international fisheries management system for the entire Northeast Asian Seas. In this context, the challenges of the reorganization of the new fisheries order are as follows: 1) conversion to a fishery order for coexistence of fisheries, 2) expansion to an international fishery management system, and 3) establishment of a multilateral fishery cooperation system. Although the jurisdiction of their own waters has been expanded through the establishment of EEZ according to new fishery order, the need for mutual cooperation grows when considering the movement and migration of fishery resources, fishery management, fish consumption and trade. In addition to the fisheries cooperation between the governments, it is also necessary to revitalize the civil cooperation focused on fishermen who exploit fishing grounds together.

• Journal of the Society of Disaster Information
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• v.15 no.1
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• pp.76-83
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• 2019

Purpose: The purpose of this study is to present data of density and speed through the experiment of the counterflow by firefighter in corridor. Method: Experimental setup including a corridor in building was prepared for measuring data with 1.5m and 2m width. Normal flow and counterflow were created for each. Data were measured using camera and acquired by video image analysis. Results: The counterflow in corridor resulted in increasing average density of about $0.55P/m^2$ and decreasing average movement speed of about 0.61 m/s. These data measured during the time when the counterflow occurred. Conclusion: It was found that counterflow by firefighter in corridor momentary increasing the density and decreasing walking speed of evacuee. Further experiments of the counterflow effect in the total evacuation time are needed.

• Journal of the Korean Geosynthetics Society
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• v.19 no.4
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• pp.1-9
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• 2020

This study analyzes contaminant movement under transient flow in a rubble mound revetment offshore waste landfill barrier system that prevents contaminant runoff. The barrier system consists of bottom layer and side barrier. For the bottom layer system, impermeable clay layer is used. For the side barrier system, the HDPE barrier sheet (primary element) plays the main role, and the intermediate protection layer (supplementary element) is responsible for the barrier. Seepage, advection, dispersion numerical analysis was carried out using SEEP / W and CTRAN / W programs. As a result, under abnormal conditions considering the fluctuation in tidal range, the volume and direction of the flow velocity vector of the pore water change with time and the dispersion concentration of the contaminant changes. When comparing the case of 2 m tidal range and 8 m tidal range, the larger the tide value, the higher the concentration of contaminant under abnormal conditions. It was found that the rate of change of the concentration of the contaminant changed depending on the change in the tidal range, and as a result, the outflow of the pollutant was smaller than that in the steady flow state.

• International Journal of Computer Science & Network Security
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• v.22 no.2
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• pp.63-74
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• 2022

Repressive measures in the Crimea against the Ukrainian media and the ban on the entry of international and Ukrainian monitoring missions created the conditions for the function of providing information to be performed by representatives of civil society. Such a phenomenon was called Crimean citizen journalism and became a post-occupation phenomenon characteristic of the Crimean information sphere. The journalists' activities are aimed at reporting on human rights violations and repression against Ukrainian citizens who find themselves in conditions of information bans and restrictions. Crimean citizen journalism, which connects the peninsula with the mainland of Ukraine, is monothematic in nature, and its emergence has become a form of nonviolent resistance to the occupation of Crimea. The purpose of the study is to cover the characteristic features, the development of common Crimean citizen journalistic movement features as a social phenomenon, a phenomenon that arose after the occupation through the identification of a modern journalist portrait. The study uses the general scientific method of empirical research as the main one, the sociological method of a questionnaire survey, as well as the methods of classification, generalisation, observation, statistical calculation. An analysis of a survey of Crimean citizen journalists demonstrates the existence of an active, mobile community in Crimea that seeks to provide information and human rights nonviolent resistance to the occupation.

• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.2
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• pp.224-234
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• 2022

This study is conducted to propose an activation plan for fisherinas by analyzing in depth the needs for fisherina development. For this purpose, the result is derived through the analysis of literature, in-depth interviews and Delphi methods. As a result, the need for fisherina development is shown as follows: first, the saturation due to the increase of maritime recreational vessels; second, the possibility of economic development; third, the activation of the fishing village economy. Accordingly, the problems of the fisherina are derived, first, the conflicts with fishermen and recreational vessel users, second, the financial difficulties, third, the lack of infrastructure. The activation plans for fisherinas are as follows: first, forming a consultative body centered on stakeholders; second, ensuring financial soundness; third, building infrastructure by linking businesses; and fourth, systematic supplementary plans. These results will play an important role in expanding the underdeveloped domestic fisherina business and will be another step in activating the maritime leisure industry.