• Journal of the Korean GEO-environmental Society
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• v.13 no.7
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• pp.5-12
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• 2012

Recently the installation of reinforced earth retaining walls in the domestic construction site has increased, surpassing conventional RC walls. These reinforced walls have various types depending on the reinforcing material, installation method and the form of face panel. However, there are difficulties in design and construction management due to the unproved safety of construction method. In case of reinforcing materials, despite the fact that they come in all different sizes and types produced by small businesses or partially imported with cheap price and low quality, no proper standards for designing the walls have been suggested. In order to apply reinforced retaining wall system to broad cases and design the walls effectively considering site conditions, specific design and construction guidelines for efficient construction management are needed. In conclusion, this study verified that reduction factors can be greatly affected by grain sizes and stiffness of backfill materials and granularity range, therefore in case of relatively large construction site, it is required to redesign the reinforced retaining wall by evaluating site installation resistance test, applying respective reduction factors to each backfill material and select the right geogrid depending on the usage of retaining wall so as to enhance the safety of reinforced earth retaining walls with efficiency.

• The Korean Journal of Emergency Medical Services
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• v.13 no.1
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• pp.87-96
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• 2009

Purpose : To grasp the mental burden for legal responsibility that rescue members have in the performance of job. Method : Questionnaire was presented to rescue members serving in 2 direct control safety centers of fire station located in Seoul, Daejon, Incheon, Kwangju, Busan, Daegu and Ulsan. Results : 1. Questioned whether they have mental burden for legal responsibility while performing job on the site, the rescue members responded : very burdensome in 38.0%, burdensome in 56.0%, moderate in 4.5%, not burdensome in 1.0%, no burden at all in 0.5%. 2. Questioned on the first aid treat for which they have the most mental burden, the rescue members responded : intubation into trachea laryngeal mask airway(LMA) in 40.4%, automatic external defibrillator in 16.3%, securing vein providing sap(medicine) in 10.8%, basic cardiopulmonary resuscitation in 7.2%, eliminating foreign matters inserted into body in 5.4%, stanching external bleeding and treating injury in 5.4%, fixing extremities and spine by using splint in 1.8%, measuring the symptom of vitality in 1.2%, providing oxygen in 0.0%. 3. Questioned whether experiencing legal problem or firm petition(complaint) raised by patient while serving as rescue members, they responded : experiencing a complaint in 41.6%, experiencing no complaint in 58.4%. Asked to indicate the stress level in the scale of which they suffered when lawsuit or firm petition was raised, 0(weak)-10(strong), they answered 8.8 in average. 4. Questioned whether 119 rescue members put the legal responsibility in case that they cause damage to patients intentionally in performing, they responded to the inquiry 3.66 in average(of 5.00). It represented meaningful differences (F=2.874, p=.024) whether they had license or not. 5. In future, legal action will raise against the rescue member by 99% because of people's rights improvement(63.1%), high expectations for the rescue system(29.5%), non-licensed rescue members(5.1%). Conclusion : It was found that the rescue members had severe mental burden for advanced life support which was investigated to have low enforcement rate in the preceding research, for instance, intubation into trachea securing vein management by using automatic external defibrillator. To improve the qualitative level of rescue service in the fire fighting, it may be required to construct the environment that eliminates the mental burden of rescue members for legal responsibility.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.9
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• pp.92-100
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• 2017

The Helicopter MRA Control Rod System has the important function of controlling the speed, height, and direction of helicoptersby adjusting the main rotor disc. However, the ingress of water into the inner control rod can cause ice damage in the rod during winter operation and also corrosion;these defects need to be rectified. The water flowed into the control rod through the upper side space, and the rod was cracked during icing expansion occurring at low temperature. The corrosion occurred due to the lack of coating process during the manufacturing process. To resolve these problems, the upper rod was sealed to prevent water inflow and a coating process was added to prevent corrosion. These solutions were verified by awaterproof test and a salt fog test. The phenomena, causes and measures were reviewed and the methods of improvement were established and proven. This proposed technology to prevent water infiltration and corrosion will contribute to the safety of rotary wing aircraft.

• Journal of Nutrition and Health
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• v.29 no.1
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• pp.22-31
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• 1996

The purpose of this study was to investigate the effect of vitamin E and selenium on the antioxidative defense mechanism in the liver of streptozotocin(STZ)-induced diabetic rats. Sprague-Dawley male rats(120$\pm$10gm) were randomly assigned to one control and five STZ-diabetic groups. Diabetic groups were classified to STZ-0E (vitamin E free diet), STZ-40E(40mg vitamin E/kg of diet), STZ-400E(400mg vitamin E/kg of diet), STZ-S(0.5ppm Se/kg of diet) and STZ-400ES(400mg vitamin E and 0.5ppm Se/kg of diet) according to the level of vitamin E and selenium supplementation. Diabetes was experimentally induced by intravenous adminstration of 55mg/kg of STZ in citrate buffer(pH 4.3) after 4-weeks feedng of six experimental diets. Animals were sacrificed at the 4th day of diabetic states. Activities of the serum glutamic oxaloacetate transaminase(GOT) and the glutaminc pyruvate transaminase(GPT) in STZ-0E, STZ-40E and STZ-S rats were higher than those of control. Liver xanthine oxidase activities were similar to serum GOT and GPT. Liver superoxide dismutase(SOD) activities were higher in STZ-0E and STZ-40E groups by 33%, 22%, respectively than that of control. Glutathione S-transferase(GST) activities of liver were similar to GSH-Px activities. The contents of vitamin E in liver tissue were significantly lower STZ-0E, STZ-40E and STZ-S groups by 50%, 36%, 45% than that of control. Reduced glutathione(GSH) contents of liver were lower STZ-0E, STZ-40E, STZ-400E, STZ-S and STZ-400ES groups by 57%, 51%, 19%, 18%, 12% than that of control. Lipid peroxide values (LPO) in liver were higher 5.6, 2.3 and 2.3 times in STZ-0E, STZ-40E and STZ-S group than that of control. The present results indicate that STZ-induced diabetic rats are more sensitive to oxidative stress, leading to the acceleration of lipid peroxidation process, which can be more accelerated by feeding the low level of dietary vitamin E. In the coincident supplementation of high dietary vitamin E and selenium antioxidative enzymes activities and physiolosical antioxidants were increased more than those of the separate supplementation of vitamin E or selenium. Therefore, dietary vitamin E and selenium reduced peroxidative damage of tissue, promoting antioxidative defense mechanism against lipid peroxidation by diabetes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.11
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• pp.494-500
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• 2019

The purpose of this study was to determine a method to prevent damage during the transfer of loading through optimal design of loading transfer software for an ammunition-carrying armored vehicle. Typically, an ammunition carrier armored car is equipped with an automated charge transfer system. The load is intermittently damaged during the loading of the cargo, and this needs to be improved. The following improvements and verification tests were carried out. As impact speed increased, the loading speed was reduced 60%, and a special fixture utilizing a force gauge was developed and tested. If the maximum current of 11A for the servo controller is output when the load of the conveyor is generated by interference inside the loading tube, there is a possibility of charge breakage. If the maximum current is low, the load cannot be loaded. In the loading test for the ammunition carrier armored car with the actual charge, the improved design was found to be valid, as the load was not damaged and occurred nominally.

• Korean Journal of Remote Sensing
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• v.36 no.5_1
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• pp.835-846
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• 2020

Recent severe climate changes and extreme weather events have caused the uncommon types of forest ecosystem disturbances such as hails and gypsy moths. This paper describes the analysis of the forest ecosystem disturbances using ISODATA (Iterative Self-organizing Data Analysis Technique Algorithm) with the RapidEye and Sentinel-2 images, regarding the cases of the hail damages in Hwasun in 2017 and the gypsy moth damages in the Chiak Mountain in 2020. In the case of hail damages, the comparison of the June image of this study and the July field survey of the previous study showed that the damage severity increased from June to July as the drought overlapped after the trees were injured by the hails. In the case of gypsy moths, significant leaf damages were found from the image of June, and the damages were mainly distributed at the low-altitude slope near Wonju City. We made sure that satellite remote sensing is a very effective method to detect various and unusual forest ecosystem disturbances caused by climate change. Also, it is expected that the Korean Medium Satellite for Agriculture and Forestry scheduled to launch in 2024 can be actively utilized to monitor such forest ecosystem disturbances.

• Korean Security Journal
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• no.25
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• pp.109-130
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• 2010

As many countries in the world including the Republic of Korea have used all their national resources in the accelerating economic information warfare, illegal leakage of industrial technologies and information has increased rapidly. The costs required for damage prevention from 2007 to 2008 are estimated at approximately KRW 180 trillion which is expected to increase gradually in future. Because the tricks of leaking key technologies are also getting increasingly systematized, sophisticated and bigger, e.g., simple theft at the individual level or the conspiracy of all the staff taking part in the research activities, we should pay special attention to technology security in addition to technology development. While there are several factors affecting such the brain drain, they usually include personal, social, political and cultural factors, for instance, very heavy educational expenditure of children compared to relatively low pay, the speedy labor market circulation for experienced personnel, or political restrictions on researches. In this context, as part of efforts made to prevent the outflow of core personnel, individual companies and research institutes should establish systematically appropriate core personnel management systems for their own organizational or business goals and principles which are intented to ensure to give better treatment and benefit to core personnel and to exercise closer supervision over them. Furthermore, the conventional personnel management system should be radically and flexibly improved in the manner of encouraging the core personnel returning to the organization to combine their external experiences with practices, instead of penalizing them. At the same time, it is necessary to train and educate core personnel through mutual collaboration and in-house training facilities as well as external academic programs operated jointly at the level of the industry. Finally, as the issues concerning the outflow of core personnel are not just problems of relevant companies and other advanced countries have devoted their best efforts to secure their own key technologies at the national level, it is urgent for the industry and the competent authorities to cooperate closely.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.551-564
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• 2020

The fashion industry in Korea has grown into a core sector that contributes to the development of national industries, but it has shown negative growth due to the advent of a low-growth era. This study aims to explore core texts related to variable factors affecting the apparel industry in Korea (and the environmental change factors of apparel companies) by using network analysis from a diachronic point of view. In addition, we discuss the implications of enhancing the value of fashion industries in Korea based on articles in fashion newspapers over five years. The conclusion of this study is as follows. First, as a suggestion for political and economic aspects, the government should minimize the damage caused by political influence by presenting new policies, or by communicating about the practical aspects of geopolitical issues and changes linked to the fashion industry. Second, as a suggestion of socio-cultural aspects, it is necessary to reduce uncertainty about the future by establishing a strategic system through cooperation with institutions that can predict future directions. Third, as a suggestion for management changes in the apparel industry, apparel companies in Korea should recognize the importance of consciousness of promoting development for a better society from coexistence, rather than corporate profit.

• Earthquakes and Structures
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• v.14 no.4
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• pp.323-336
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• 2018

Machine foundations with impact loads are common powerful sources of industrial vibrations. These foundations are generally transferring vertical dynamic loads to the soil and generate ground vibrations which may harmfully affect the surrounding structures or buildings. Dynamic effects range from severe trouble of working conditions for some sensitive instruments or devices to visible structural damage. This work includes an experimental study on the behavior of dry dense sand under the action of a single impulsive load. The objective of this research is to predict the dry sand response under impact loads. Emphasis will be made on attenuation of waves induced by impact loads through the soil. The research also includes studying the effect of footing embedment, and footing area on the soil behavior and its dynamic response. Different falling masses from different heights were conducted using the falling weight deflectometer (FWD) to provide the single pulse energy. The responses of different soils were evaluated at different locations (vertically below the impact plate and horizontally away from it). These responses include; displacements, velocities, and accelerations that are developed due to the impact acting at top and different depths within the soil using the falling weight deflectometer (FWD) and accelerometers (ARH-500A Waterproof, and Low capacity Acceleration Transducer) that are embedded in the soil in addition to soil pressure gauges. It was concluded that increasing the footing embedment depth results in increase in the amplitude of the force-time history by about 10-30% due to increase in the degree of confinement. This is accompanied by a decrease in the displacement response of the soil by about 40-50% due to increase in the overburden pressure when the embedment depth increased which leads to increasing the stiffness of sandy soil. There is also increase in the natural frequency of the soil-foundation system by about 20-45%. For surface foundation, the foundation is free to oscillate in vertical, horizontal and rocking modes. But, when embedding a footing, the surrounding soil restricts oscillation due to confinement which leads to increasing the natural frequency. Moreover, the soil density increases with depth because of compaction, which makes the soil behave as a solid medium. Increasing the footing embedment depth results in an increase in the damping ratio by about 50-150% due to the increase of soil density as D/B increases, hence the soil tends to behave as a solid medium which activates both viscous and strain damping.

• Journal of Nutrition and Health
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• v.31 no.5
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• pp.906-913
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• 1998

This study an analyzes the effects of the P/S ratio of dietary lipids and antioxidant vitamin supplements on serum lipids level and fatty acid profile, the degree of lipid peroxidation, and the antioxidant enzyme activities in the liver of rats treated with 7,12-dimethylbenz($\alpha$) anthracene(DMBA). P/S ratio of dietary lipids was made into 0.5, 1 and 2 by mixing palm oil, soybean oil, sesame oil and perilla oil at 10%(w/w) fat level and n-6/n-3 ratio was fixed to 4. Antioxidant vitamin of $\alpha$-tocopherol or $\beta$-carotene was supplemented in addition to vitamin mixture which was given at 1 % of the standard diet. female Sprague-Dawley strain rats, about 60 days old, were divided into three groups(LP : low P/S ratio(0.5), MP : medium P/S ratio (1.0), HP , high P/S ratio(2.0)) and each group was sub-divided into three groups(S ; standard, T ; tocopherol supplemented, C : carotene supplemented): Two weeks after feeding experimental diets, all groups were treated with a single dose of DMBA(2mg/100g BW) by gastric intubation and fed experimental diet for 9 week. The results were as follows ; 1) Serum total cholesterol(TC) level was not significantly influenced by diet but tended to be lower in HP groups compared to LP and MP groups. Triglyceride level was the highest in LP groups and the lowest in $\alpha$-tocopherol supplemented groups. 2) Thiobarbituric acid reactive substance(TBARS) level, representing lipid peroxidation in hepatic microsome, tended to be increased as the unsaturation of dietary lipids increases. $\alpha$-Tocopherol supplement significantly decreased TBARS level. 3) The activities of superoxide dismutase(SOD) and glutathione peroxidase(GSHPx) in hepatic cytosol showed the tendency to be high with increasing P/S ratio of dietary lipids. SOD activity was not significantly influenced by antioxidant vitamin, but GSHPx activity was significantly increased in $\alpha$-tocopherol supplemented groups. In summary, high polyunsaturated fat diet was effective on reducing the serum level of total cholesterol and triglyceride, while it increased unsaturation and peroxidizability of serum fatty acid. With increasing P/S ratio of dietary lipids, lipid peroxidation was increased in the liver and antioxidant enzyme system was induced to inhibit lipid peroxidation against oxidative damage. $\alpha$-Tocopherol supplement was effective in lowering lipid peoxidation, but $\beta$-carotene supplement did not exhibit antioxidant effect. (Korean J Nutrition 31(5) 906~913, 1998)