• Journal of the Korean Society of Marine Environment & Safety
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• v.28 no.1
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• pp.153-160
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• 2022

This study presents the bogie arrangement of the load-out system for on-ground shipbuilding. The load-out system is one of the most important systems to perform the bogie arrangement of the on-ground shipbuilding technique without dry dock facilities, and this system is composed of four pieces of equipment: bogies, driving bogie with motors, trestles, and power packs. Also, the bogie arrangement analysis (BAA) is employed to simply calculate the reaction forces at the trestle for structural safety. In this context, the purpose of this study is to propose an optimal design method to perform the bogie arrangement satisfying structural safety requirements with minimal cost. It is expected that the proposed methodology will contribute to the effective practice as well as to the improvement of competitive capability for shipbuilding companies at the on-ground shipbuilding stage. Furthermore, we describe some problems and their solutions of the deformation that may occur in the bottom of the hull during the load-out process. As a result, it is shown that we applied it to the 114K crude oil tanker (Minimum bogie 54EA) and the 174K CBM LNG carrier (Minimum bogie 88EA), it can minimize the number of bogie and critical risks (Safety rate 1.61) during the load-out of on-ground shipbuilding. Through this study, the reader will be able to learn successful load-out operation and economic shipbuilding in the future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1346-1355
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• 2012

This study was carried out to investigate the characteristics of black jujube and Zizyphus jujube extracts during lactic acid fermentation. Both extracts were fermented using Lactobacillus fermentum YL-3. As a result, viable cell number rapidly increased until 24 hours, after which it gradually decreased. Before lactic acid fermentation, the $IC_{50}$ of black jujube, which was 0.014 mg/mL, was lower than that of Zizyphus jujube. Further, black jujube showed stronger antioxidant activity (374.21 mg AA eq/g) than Zizyphus jujube. Contents of total polyphenolics in both extracts were 15.46 mg/g and 13.61 mg/g, respectively, whereas contents of total flavonoids were 374.21 ${\mu}g/g$ and 64.25 ${\mu}g/g$. After lactic acid fermentation, there was no significant increase in DPPH or ABTS free radical scavenging activity. Total polyphenolic content of Zizyphus jujube decreased to 12.39 mg/g upon fermentation, whereas flavonoid content significantly increased to 291.58 ${\mu}g/g$. Further, polyphenolic and flavonoid contents of black jujube increased from 15.46 mg/g to 17.46 mg/g and from 374.21 ${\mu}g/g$ to 1,135.29 ${\mu}g/g$, respectively. These results demonstrate that 9-Times Steamed and Dried increased functional components. Especially, lactic acid fermented black jujube showed remarkably high antioxidant activity. These results confirm the potential use of lactic acid fermented black jujube as a valuable resource for the development of functional foods.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.2
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• pp.121-127
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• 1985

This study was designed to gain practical data on the use of soil conditioners for more efficient water managements and to establish the optimum levels of structural properties for soil conditioning. A sandy loam and a silt loam soil were each treated with two different soil conditioners, hydrophobic Bitumen or hydrophilic Uresol. The perspex tube 34 cm long were packed homogeneously with air dried soil up to 2 cm below the top, then covered over 2 cm of treated or untreated aggregates. The infiltration rate into the soil columns was measured under simulated rainfall condition. The evaporation study was carried out in the wind tunnel, and the changes of soil moisture distribution of the columns following and during the evaporation were determined by a gamma ray scanner. The infiltration rate of water into the soil column was increased to 18.7-50.8% by the Uresol treatment but it was decreased to less than 25% of control by the Bitumen treatment. Evaporation was decreased to 22.0-68.1% by the Bitumen treatment and to 38.7-68.4% by the Uresol treatment. The water use efficiency of Uresol treated column was increased to more than twice as much as that of untreated soil. Aggregate stability and wetting angle were related to water infiltration and evaporation. A positive and highly significant logarismic relationship was found between the infiltration rate and stability index-wetting angle, evaporation rate and instability index-wetting angle. It was considered that the structural stability is more important than wetting angle. This is true because the structural stability is always positively correlated to water saving, however wettability is positively correlated to the infiltration, and negatively correlated to water saving during the evaporation.

• Fire Science and Engineering
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• v.17 no.4
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• pp.76-85
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• 2003

In this study, we write down the definitions, their causes and the techniques of analysis as a theoretical consideration of common cause failures, and investigate the limitation and the importance of the common cause failures by applying to the analysis on the fire protection as a representative safety facility. As you can know in the reliability analysis, most impressive cause is the malfunctions of pumping operations; especially the common cause failure of two pumps is dominant. In other words, it is possible to assess system-reliability as twice as actual without CCF From these, CCF is extraordinarily important and the results are highly dependent on the CCF factor. And although it would increase with multiple installations, the reliability are not defined as linear with those multiplications. In addition, the differences in results due to the models for analysis are not significant, whereas the various sources of data produce highly different results. Therefore, we conclude that the reliabilities are dependent on the quality of the usable data much better than the variety of models. As a result, the basic and engineering device for the preventions of CCF of the multiple facilities is to design it as reliably as to design the fire-water pump. That is to say, we must assess those reliabilities using PFD whether they are appropriate to SIL (Safety Integrity Level) which is required for the reliability in SIS (Safety Instrumented System). The result of the analysis on the reliability of the fire-water supply with CCF shows that PFD is 3.80E-3, so that it cannot be said to be designed as safely as in the level of SIL5. However, without CCF, PFD is 1.82E-3 which means that they are designed as unsafely as before.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.4
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• pp.500-508
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• 2011

This study was carried out to investigate the effects of jujube extracts on intestinal microflora, along with their antioxidant activities, according to extraction method. The antimicrobial activities of the extracts were measured using the agar diffusion method with a jujube extract concentration of 50 mg/mL. Neither the first nor second jujube extracts were inhibitory against the tested intestinal bacteria. However, water extracts of jujube significantly enhanced the growth of lactic acid bacteria, especially Bifidobacterium bifidum and Bifidobacterium adolescentis. Total phenol compounds and flavonoid compounds were higher in the 1st than in the 2nd water extracts. The EDA values of both water and ethanol extracts increased in proportion to the extract concentration. The 1st water extract showed the highest value among all the others, which was 85.60% at the concentration of 0.05 mg/mL. Furthermore, the 1st water extract showed stronger antioxidant activity than the other samples with an activity of 679.91 mg AA eq/g. These results support the potential use of jujube water extracts as a functional food component and a valuable resource for the development of nutraceutical foods, to increase the growth of Bifidobacterium spp. in the human intestine.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2003.05a
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• pp.181-186
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• 2003

The satellite navigation system is widely used for identifying a user's position regardless of weather or geographic conditions and also make effect on new technology of marine LBS(Location Based Service), which has the technology of geographic information such as the ENC. Generally, there are conceivable systems of marine LBS such as ECDIS, or ECS that use the ENC itself with powerful processor in installed type on ships bridge. Since the ENC is relatively heavy structure with dummy format for data transfer between different systems, we should reduce the ENC to small and compact size in order to use it in mobile platform. In this paper, we assumed that the mobile system like PDA, or Webpad can be used for small capability of mobile platform. However, the ENC should be updated periodically by update profile data produced by HO. If we would reduce the ENC without a consideration of update, we could not get newly updated data furthermore. As summary, we studied considerations for ENC reduction with update capability. It will make the ENC be useful in many mobile platforms for various applications.

• Korean Journal of Remote Sensing
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• v.39 no.2
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• pp.129-142
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• 2023

This study analyzed the ratio of carbon monoxide (CO) and carbon dioxide (CO₂), CO and nitrogen dioxide (NO₂) for cities and regionsin Korea and China using column-averaged carbon dioxide dry-air mole fraction (XCO₂) of the Orbiting Carbon Observatory-2/3, CO and NO₂ vertical column density (named XCO, XNO₂ in thisstudy) of TROPOspheric monitoring instrument from April 2018 to April 2022, and presented the relationship between socioeconomic indicators (population, number of vehicles, Gross Regional Domestic Product) and ratio, and differences in characteristics between Korea and China. First, CO₂ and CO were analyzed after calculating ΔXCO₂ and ΔXCO removing the background value and trend line due to the difference in atmospheric residence time of three gaseous substances (CO₂, CO, and NO₂). Comparing the three values by regions, ΔXCO and ΔXCO₂ were relatively higher in China and XNO₂ were higher in Korea and the ratio of both values (ΔXCO/ΔXCO₂, ΔXCO/XNO₂) was higher in China than in Korea. ΔXCO/ΔXCO₂, ΔXCO/XNO₂ and socioeconomic indicators have a positive correlation suggesting that the concentration of air pollutants and greenhouse gases is higher as the city is large and the economic activity is active. Regarding the differences in the ratio characteristics of Korea and China, the relationship between ΔXCO and ΔXCO₂ showed a negative correlation in Korea and a positive correlation in China. When the relationship between ΔXCO and XNO₂ was examined for summer and winter, the change of ΔXCO by season was not significant in Korea, whereasthe change of ΔXCO and XNO₂ by season waslarge in China resulting in the relationship between two countries appeared differently. These results suggest that seasonal variability and national emission characteristics should be considered in the process of analyzing the ratio of greenhouse gases to air pollutants.

• Journal of Soil and Groundwater Environment
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• v.13 no.1
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• pp.1-12
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• 2008

The purpose of this study is to characterize the hydrogeochemical characteristics of hot spring waters and to interpret the source of noble gases and the geochemical environment of the hot spring waters distributed along the eastern area of the Korean peninsula. For this purpose, We carried out the chemical, stable isotopic and noble gas isotopic analyses for eleven hot spring water and fourteen hot spring gas samples collected from six hot spring sites. The hot spring waters except the Osaek hot spring water show the pH range of 7.0 to 9.1. However, the Osaek $CO_2$-rich hot spring water shows a weak acid of pH 5.7. The temperature of hot spring waters in the study area ranges from $25.7^{\circ}C$ to $68.3^{\circ}C$. Electrical conductivity of hot spring waters varies widely from 202 to $7,130{\mu}S/cm$. High electrical conductivity (av., $3,890{\mu}S/sm$) by high Na and Cl contents of the Haeundae and the Dongrae hot spring waters indicates that the hot spring waters were mixed with seawater in the subsurface thermal system. The type of hot springs in the viewpoint of dissolved components can be grouped into three types: (1) alkaline Na-$HCO_3$ type including sulfur gas of the Osaek, Baekam, Dukgu and Chuksan hot springs, and (2) saline Na-Cl type of the Haeundae and Dongrae hot springs, and (3) weak acid $CO_2$-rich Na-$HCO_3$ type of Osaek hot spring. Tritium ratios of the Haeundae and the Dongrae hot springs indicate different residence time in their aquifers of older water of $0.0{\sim}0.3$ TU and younger water of $5.9{\sim}8.8$ TU. The ${\delta}^{18}O$ and ${\delta}D$ values of hot spring waters indicate that they originate from the meteoric water, and that the values also reflect a latitude effect according to their locations. $^3He/^4He$ ratios of the hot spring waters except Osaek $CO_2$-rich hot spring water range from $0.1{\times}10^{-6}$ to $1.1{\times}10^{-6}$ which are plotted above the mixing line between air and crustal components. It means that the He gas in hot spring waters was originated mainly from atmosphere and crust sources, and partly from mantle sources. The Osaek $CO_2$-rich hot spring water shows $3.3{\times}10^{-6}$ in $^3He/^4He$ ratio that is 2.4 times higher than those of atmosphere. It provides clearly a helium source from the deep mantle. $^{40}Ar/^{36}Ar$ ratios of hot spring water are in the range of an atmosphere source.