• International Journal of Naval Architecture and Ocean Engineering
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• v.11 no.1
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• pp.396-408
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• 2019

The tubes which are applied in jacket platforms as the supporting structure might be collided by supply vessels. Such kind of impact will lead to plastic deformation on tube members. As a result, the ultimate strength of tubes will decrease compared to that of intact ones. In order to make a decision on whether to repair or replace the members, it is crucial to know the residual strength of the tubes. After being damaged by lateral impact, the simply supported tubes will definitely loss a certain extent of load carrying capacity under uniform axial compression. Therefore, in this paper, the relationship between the residual ultimate strength of the damaged circular tube by collision and the energy dissipation due to lateral impact is investigated. The influences of several parameters, such as the length, diameter and thickness of the tube and the impact energy, on the reduction of ultimate strength are investigated. A series of numerical simulations are performed using nonlinear FEA software LS-DYNA. Based on simulation results, a non-dimensional parameter is introduced to represent the degree of damage of various size of tubes after collision impact. By applying this non-dimensional parameter, a simplified formula has been derived to describe the relationship between axial compressive residual ultimate and lateral impact energy and tube parameters. Finally, by comparing with the allowable compressive stress proposed in API rules (RP2A-WSD A P I, 2000), the critical damage of tube due to collision impact to be repaired is proposed.

• Journal of Korean Society of Disaster and Security
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• v.13 no.4
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• pp.93-104
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• 2020

Climate change has emerged as a social issue, and efforts have been made to overcome it in various ways. However, climate change due to global warming is likely to accelerate further than we expected, and the associated damage is also likely to increase. This tendency is expected to continue in the future, leading to difficulties for the existing water resource management system based on historical data. The precipitation in 2020 caused property damage and loss of life due to the extreme rainfall exceeding the design rainfall with the very unusual prolonged rainy days. With this 2020 flood, we should no longer be passive in managing flood risk due to uncertainties in climate change.

• Journal of the Earthquake Engineering Society of Korea
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• v.12 no.3
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• pp.1-10
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• 2008

The seismic performance of a structure designed without consideration of seismic loading can be effectively enhanced through seismic rehabilitation. The appropriate level of rehabilitation should be determined based on the decision criteria that minimize the anticipated earthquake-related losses. To estimate the anticipated losses, seismic risk analysis should be performed considering the probabilistic characteristics of the hazard and the structural damage. This study presents the decision procedure in which the probabilistic seismic demand model is utilized for the effective estimation and minimization of the total seismic losses through seismic rehabilitation. The probability density function and the cumulative distribution function of the structural damage for a specified time period are established in a closed form, and are combined with the loss functions to derive the expected seismic loss. The procedure presented in this study could be effectively used for making decisions on the seismic rehabilitation of structural systems.

• Journal of Korean Academy of Nursing
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• v.26 no.2
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• pp.290-303
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• 1996

There is a need to define the concept of suffering more appropriate in the context of Korean culture. This research is an attempt to analyze and develop the concept of suffering by applying the Hybrid Model suggested by Schwartz-Barcott and Kim. The data were collected from March 20, 1995 to September 17,1995. The subjects of the study were eight persons including in-patients and out-patients of a general hospital who were diagnosed as having cancer and those resting in sanatoria for natural treatment of cancer. Qualitative research methods of in-depth interview and participant observation were used for data collection. The contents of the interviews were recorded on tape. Data-analysis progressed according to the 3 phases suggested by the Hybrid Model. For each case, in-depth interview data and participant observation data were included and the attributes of suffering revealed in these data were analyzed. Finally, by summarizing the results from each case, the attributes of suffering, its dimensions, definition, and processes observed in the field were suggested. According to the results of the study, the followlng new definition of suffering is suggested : Suffering is a fundamental and inevitable experience of all human beings. When each individual experiences loss, damage, and pain which threaten one's personal integrity, suffering is perceived differently among each individual depending on their personal inner factors, one's significant others, exterior circumstances and stimuli, and the ultimate meaning of life. Suffering brings severe and unendurable distress which accompany despair, powerlessness, anxiety, bitterness, fear, anguish, guilt, depression, withdrawal and anger. The results of this study suggest that the more responsibility and burden a cancer patient felt, the more suffering she/he experienced and it tended to be more relevant to one's significant others and exterior circumstances and stimuli : the less responsibility and burden a cancer patient had, the less suffering she/he experienced and it tended to be related to one's inner factors. These findings have implications for nursing profession. When caring for patients who experience suffering, nurses need to consider the influence of responsibility, burden, and each dimension of suffering. Moreover, appropriate nursing interventions aimed at relieving pain and satisfying the spiritual need of patients experiencing loss need to be developed and implemented more widely.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.6_2
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• pp.599-611
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• 2007

Among natural disasters that lead to devastating damage, floods from heavy rains have been causing hundreds of victims and a great loss of their properties every year. Basically, there is no other way to deal with the problem considering the characteristics of natural disaster, but more specific studies for a preventive measure of flood has been in progress so far. However, the controversy over the problem is going on due to the objection of some environmental organizations or some economic reasons. The key point is to select the most likely area for a preventive measure of floods where a huge amount of the national budget is put into it. This is the factor which judges whether it would be a success or failure. This study aims to provide some basic data for deciding the priority order in a disaster preventing plan by drawing more potential damage areas from the connection with GIS and using them into the economic analysis for flood prevention industries.

• The Journal of the Korea Contents Association
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• v.18 no.2
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• pp.169-177
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• 2018

There is a lot of loss of life due to natural disasters. In particular, flood damage caused by heavy rainfall in urban areas causes serious damage. Therefore, in this study, we conducted a study on the optimal evacuation route for safe evacuation of urban areas. We set up a methodology by reviewing Flo-2D model and A* algorithm. A Flo-2D model was used to derive the hazardous area, and we selected the starting points with many people and suggested ways to select safe evacuation sites. And the route was derived from the starting point to the safe evacuation point by using the A * algorithm. This study could be used not only for evacuation route but also for road maintenance and evacuation facilities.

• Journal of the Korean Society of Marine Environment & Safety
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• v.18 no.5
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• pp.481-487
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• 2012

Recently, the construction of the small Al alloy ships is an increasing trend in viewpoint such as the disposal issue of a retired ship, the enhancement of environmental regulation and resources recycling etc. for FRP ships. However, Al alloy ship which can achieve high speed by light weight in marine environment is exposed to a problem on materials damage by cavitation-erosion which is generated by large impact pressure with the collapse of air bubbles due to cavitation. Consequently, in this study, water cavitation peening technology was applied in Al alloy for ship to enhance durability life by preventing cavitation damage. So, the water cavitaton peening application time that presented the excellent cavitation characteristic investigated. The weight-loss of 5456-H116, 5083-H321 and 5052-O Al alloy at the optimum water cavitation peening time were improved to 42.11 %, 50.0 % and 25.7 %, respectively.

• Journal of the Korean Geophysical Society
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• v.9 no.4
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• pp.455-462
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• 2006

In this paper, we used the electrical resistivity survey as a simple and reasonable technique to evaluate the effectiveness of grouting. And, a mechanism was also analyzed to understand how the electrical resistivity is affected by the loss of fine material in the core of a dam. From this mechanism, it was confirmed that electrical resistivity value of the damage section may be up or down depending on the survey conditions. This result seems to be contrary to the previous study that electrical resistivity of the damage zone become alway low. To clarify what was investigated, the electrical resistivity before and after grouting was compared and analyzed. As the result, it was concluded that grouting effectiveness was successfully assessed by electrical resistivity survey.

• The Journal of the Petrological Society of Korea
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• v.26 no.1
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• pp.55-62
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• 2017

A Lahar on the volcanic area is one of the important hazard that can cause the loss of life and property damage. In order to estimate lahar hazard area at Ulleung Island, we simulated lahar inundation area using Laharz_py. We assumed 400 m of additional elevation for DEM to draw proximal hazard zone of Ulleung Island that H/L ratio were selected 0.45 and 0.5. And lahar volumes for simulation were estimated to 30,000, 50,000, 70,000, $100,000m^3$, respectively. In the results, 5 streams are located near a proximal hazard zone, Jeodong (east), Sadong and Okchon (southeast), Namyang (southwest), and Chusan (north), Nari basin is also considered that has a possibility of lahar during downpour. The results of this study can be used as basic data to make a hazard map for reduce the damage that can be caused by volcanic hazards occurred on Ulleung Island.

• Journal of the Korean Institute of Intelligent Systems
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• v.22 no.6
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• pp.715-721
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• 2012

A threat evaluation is the technique which decides order of priority about tracks engaging with enemy by recognizing battlefield situation and making it efficient decision making. That is, in battle situation of multiple target it makes expeditious decision making and then aims at minimizing asset's damage and maximizing attack to targets. Threat value computation used in threat evaluation is calculated by sensor data which generated in battle space. Because Battle situation is unpredictable and there are various possibilities generating potential events, the damage or loss of data can make confuse decision making. Therefore, in this paper we suggest that substantial threat value calculation using learning bayesian network which makes it adapt to the varying battle situation to gain reliable results under given incomplete data and then verify this system's performance.