• Korean Journal of Environment and Ecology
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• v.32 no.2
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• pp.140-146
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• 2018

Wild boars have expanded their habitats in Korea in recent years and caused serious social problems such as crop damage and appearance in urban areas. This study was carried out from May to October 2012 to investigate the environmental factors that affect crop damage based on actual cases reported in Geochang County of Gyeongnam Province, Korea. The analysis showed that the damages by wild boars occurred mainly between August and September, and rice was damaged most often while sweet potatoes were damaged most intensely. The results indicated that the damages were related to the wild boars' preference of crop and the seasonal availability of crops. Other factors that affected the crop damage included the slope, the topographic relief, and the distances from forest, stream, road, and residential area. There was no significant difference of environmental factor according to damage intensity, suggesting that the wild boars tended to attack the same cropland repeatedly and thus accumulating the damage. Our study suggests that reducing crop damages by wild boars will require cultivating crops less preferred by wild boars, installing electric fences, and controlling wild boar population with hunting and trapping.

• The Journal of the Korean dental association
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• v.58 no.10
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• pp.627-638
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• 2020

This study was conducted to identify the subjective damage caused by COVID-19 and its related factors. The study subjects were members of the Korean Dental Association (KDA). We investigated the damage to dental clinics and hospitals caused by COVID-19 between January and April 2020. After analyzing the final 3,189 responses, the rate of decrease in patients was the highest at 34.9% in March, and the rate of decrease in income was the highest at 34.0% in April. As a result of the multilevel analysis, the damage caused by COVID-19 was greater in regions with more confirmed patients, more careers, and fewer dental staff. The government should establish a compensation plan for hospitals and clinics to prevent the collapse of the medical system due to the prolonged COVID-19. In addition, support for dentistry should be provided to maintain the oral health care system in the future.

• Journal of Hydrogen and New Energy
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• v.28 no.6
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• pp.635-641
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• 2017

In this study, the components of packaged hydrogen filling station were analyzed and risk factors were examined. Risk scenarios were constructed and quantitative risk assessments were conducted through a general risk assessment program (phast/safeti 7.2). Through the risk assessment, the range of damage according to accident scenarios and the ranking that affects the damage according to the risk factors are listed, and scope of damage and countermeasures for risk reduction are provided. The quantitative risk assessment result of the packaged hydrogen filling station through this task will be used as the basic data for improving the safety of the packaged filling system and preparing safety standards.

• Journal of Advanced Marine Engineering and Technology
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• v.23 no.4
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• pp.453-461
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• 1999

The estimation of fatigue life at the design stage is very important in order to arrive at feasible and cost effective solutions considering the total lifetime of the structure and machinery compo-nents. In this study the practical procedure of prediction of fatigue life by use of cumulative damage factors based on Miner-Palmgren hypothesis and probability density function is shown with a $135,000m^3$ LNG tank being used as an example. In particular the parameters of Weibull distribution taht determine the stress spectrum are dis-cussed. At the end some of uncertainties associated with fatigue life prediction are discussed. The main results obtained from this study are as follows: 1. The practical procedure of prediction of fatigue life by use of cumulative damage factors expressed in combination of probability density function and S-N data is proposed. 2. The calculated fatigue life is influenced by the shape parameter and stress block. The conser-vative fatigue design can be achieved when using higher value of shape parameter and the stress blocks divded into more stress blocks.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.104-104
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• 2003

Geosynthetic Reinforcements - membrane drawn type, warp/knitted type, junction bonded type and composite type geogrids, strip type reinforcement - were used to compare the long-term perfor-mance by total factor of safety with reduction factors during service periods. To evaluate the reduction factors, wide-width tensile property, installation damage, creep deformation, chemical and biological degradation tests were performed. Long-term design strengths of geosynthetic reinforcements were calculated by using GRI standard Test Method GG4.

• Journal of Wetlands Research
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• v.21 no.2
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• pp.157-162
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• 2019

Recently, the occurrence of unusual heavy snow and cold are increasing due to the unusual global climate change. In particular, the temperature dropped to minus 69 degrees Celsius in the United States on January 8, 2018. In Korea, on February 17, 2014, the auditorium building in Gyeongju Mauna Resort was collapsed due to the heavy snowfall. Because of the tragic accident many studies on the reduction of snow damage is being conducted, but it is difficult to predict the exact damage due to the lack of historical damage data, and uncertainty of meteorological data due to the long distance between the damaged area and the observatory. Therefore, in this study, available data were collected from factors that are thought to be corresponding to snow damage, and the amount of snow damage was estimated categorically using a random forest. At present, the prediction accuracy was not sufficient due to lack of historical damage data and changes of the design code for green houses. However, if accurate weather data are obtained in the affected areas. the accuracy of estimates would increase enough for being used for be the degree preparedness of disaster management.

• Nuclear Engineering and Technology
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• v.54 no.1
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• pp.84-96
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• 2022

In the worst case, a temporary ignition source (also known as transient combustibles) between two electrical panels can damage both panels. Mitigation strategies for electrical panel fires were previously developed using fire modeling and risk analysis. However, since they do not comply with deterministic fire protection requirements, it is necessary to analyze the boundary values at which combustibles may damage targets depending on various factors. In the present study, a sensitivity analysis of input variables related to the damage threshold of two electrical panels was performed for dimensionless geometry using a Fire Dynamics Simulator (FDS). A new methodology using a damage evaluation map was developed to assess the damage of the electrical panel. The input variables were the distance between the electrical panels, the vertical height of the fuel, the size of the fire, the wind speed and the wind direction. The heat flux was determined to increase as the vertical distance between the fuel and the panel decreased, and the largest heat flux was predicted when the vertical separation distance divided by one half flame length was 0.3-0.5. As the distance between the panels increases, the heat flux decreases according to the power law, and damage can be avoided when the distance between the fuel and the panel is twice the length of the panel. When the wind direction is east and south, to avoid damage to the electrical panel the distance must be increased by 1.5 times compared to no wind. The present scale model can be applied to any configuration where combustibles are located between two electrical panels, and can provide useful guidance for the design of redundant electrical panels.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.50 no.3
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• pp.271-278
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• 2024

The human skin is an organ that protects the body from physical and chemical factors. The skin is the largest and most massive of the body's organs and is composed of the epidermis, dermis, and subcutaneous tissue. Constant UV exposure to the skin can cause DNA damage, oxidation of proteins, and contribute to adult diseases. Nypa fruticans Wurmb (NF), rich in phytochemicals (polyphenols and flavonoids), has been traditionally used for treating respiratory and other diseases. This study investigated the effects of NF ethyl acetate fraction (ENF) on DNA damage healing and inhibition of wrinkle-related factors in UVB-stimulated Hs68 cells. Westernblotting was used to assess the expression of DNA damage-related proteins and wrinkle-related protein factors. In addition, the wound recovery capability of ENF was confirmed through wound-healing experiments. ENF significantly suppressed the expression of DNA damage-related proteins Phosphorylated H2AX (γ-H2AX), checkpoint kinase 2 (Chk2), protein53 (p53), and Phosphorylated protein53 (p-p53). Furthermore, ENF inhibited the expression of wrinkle-related proteins matrix metalloproteinase-1 (MMP-1), matrix metalloproteinase-3 (MMP-3), and matrix metalloproteinase-9 (MMP-9). High concentrations of ENF also enhanced wound healing in Hs68 cells. ENF is thought to have the potential to heal DNA damage by significantly suppressing the expression of γ-H2AX, Chk2, p53, and p-p53, as well as to inhibit wrinkle formation by suppressing the expression of MMP-1, MMP-3, and MMP-9. These results suggest that ENF can be used as a natural resource to suppress skin damage caused by UVB by regulating the γ-H2AX, Chk2, p53, and MMP pathways in Hs68 cells induced by UVB.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.06b
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• pp.141-146
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• 1999

In the stage of process design, many factors affecting tool life should be considered. Wear, Damage Accumulation and excessive die Stress are those. Most Engineer think wear and damage accumulation affection deeply to the cold forging dies and wear for the hot forging dies. In this report, the example that wear and stress distribution affect tool life in hot forging together will be introduced and the way to solve that problem using Finite Element Method.

• International conference on construction engineering and project management
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• 2005.10a
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• pp.758-763
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• 2005

For international projects in general and the projects in the Gulf area in Particular, the most common cause of construction disputes and claims is construction delay. This paper will present different surveys to identify the causes of delay, the parties responsible, and how delay can be avoided. This paper will outline how these factors impact damage assessment and entitlement. Furthermore, a case study will be presented to show how the responsibility and damages due to delay are assessed and how entitlements are calculated.