• Journal of Korean Society of Transportation
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• v.24 no.1 s.87
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• pp.19-28
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• 2006

To develop a crisis management for aviation safety, this study has defined crisis management includes risk management which is eliminates or lowers risks prior to accidents and emergency response after the accidents. This study takes a look at different kinds of crisis managements, risk managements and statistical methods of other nations and fields in order to develop a risk management model. Through surveys which have 102 risk factors that include air traffic control, maintenance and airport sectors, the weight of each risk factor was calculated and the probability was divided to develop a model for risk management. The risk management model of this study is conducted using four steps (risk management plan, risk factor identification, weight and probability analysis, decision making) and 4 standards of weight along with 5 standards of probability This study takes a look at Predictions through a quantitative method using a risk index for the risk management model An effective risk management model should have a wide and continuous collection of data and adopt various methods using this model. The crisis management could not be very effective only using a pre-active risk management. So it should also be conducted by using a pro-active response system to protect additional damage and to prevent accidents of the same nature. From the results, the most important points were the establishment of command and control accountabilities, and cooperation of related organizations.

• The Journal of Engineering Geology
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• v.26 no.1
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• pp.63-70
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• 2016

The aim of this study is the safety and an accident prevention in limestone terrain by the underground tunneling. The geology of the study area consists of a Paleozoic sedimentary sequence dominated by limestone, sandstone, shale, and carbonaceous shale. The sequence gently dips to the northeast but the joint contains steep with variable trend. A significant fracture zone is developed in the limestone and shale beds, sub-parallel to bedding, and follows in part the limestone-sandstone contact. Monitoring of groundwater levels in the area shows marked fluctuations in the water table, which repeatedly rose to a level of -4 m before sinking to -15 m. These cycles occurred in mid-May, 2007 and in early and middle June. The data indicate that these fluctuations were unrelated to rainfall that occurred during the study period. We infer that the fluctuations were associated with the development of underground karstic networks along the deep fracture zone, and overlying ground subsidence is likely related to the rapid sinking of groundwater and the associated strong downward suction force.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.250-255
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• 2017

When an earthquake occurs, it is necessary to evaluate the site-specific ground response while considering ground characteristics in seismic design. The design seismic force of Korean seismic design criteria is borrowed from the Uniform Building Code(UBC-1997). However, the criteria are based on the ground characteristics of the United States, which are different from the ground characteristics in Korea, and using them could cause over-or under-designing. Therefore, it is important to develop a proper design response spectrum for Korean ground characteristics. In this study, 158 ground sites in Korean urban areas were selected and compared to those in the western part of the United States, and their site-specific ground responses were analyzed. The classification standard in the seismic design criteria classifies the 158 sites into 37 sites, 107 sites, and 14 sites. Using 7 earthquake inputs, the criteria were compared for each group.The Korean design response spectrum underestimates the amplification of the short-period range and overestimates the amplification in the long-period range. There were large differences in the results of the and sites,which account for 77 percent of the 158 sites. Therefore, there is a need to modify the amplification factor in the Korean seismic criteria to properly reflect Korean ground characteristics.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.7
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• pp.33-38
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• 2017

The number of damaged lifeline structures have been increasing with urban acceleration under earthquakes. To predict the damage, damage mitigation technology of lifeline structures should be analyzed using damage prediction technology. Therefore, in this paper, the degree of the fragility of structures under an earthquake was evaluated stochastically through an evaluation of the seismic fragility. The aim was to develop damage prediction technology of sewage pipes among the lifeline facilities. The site response was performed using the data from 158 boreholes in Seoul and 7 real earthquake waves to determine the responses in real urban areas. The seismic fragility was deduced through a total of 29822 time history analysis. In addition, sewer pipes were evaluated and the persisting period was passed by applying the research results of strength reduction which is due to sulphate erosion. As a result, the difference in failure probability between 300 and 800 with the smaller diameter of the representative pipes was approximately double and the size of the pipes has a significant effect on the seismic fragility function. Moreover, the failure probability of a seismic load increases by up to 10 fold as the strength reduction rate increases. The results of this study can be used as a means of predicting the damage and countermeasures of sewer pipes and might be reflected in the seismic design of underground facilities.

• Journal of Korean Tunnelling and Underground Space Association
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• v.20 no.1
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• pp.145-160
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• 2018

Long subsea tunnel is subject to many restrictions in terms of spatial limitation when vertical or inclined shafts are built for tunnel ventilation. So, the construction of some artificial island is required to provide ventilation. But, because of construction difficulty and cost increase, it is necessary to minimize the artificial island construction. As a result, ventilation distance become longer and supply airflow becomes excessive due to air leakage, So, duct mounting for temporary ventilation is impossible or fan pressure and power increase exponentially. Therefore, in order to build a long subsea tunnel, it is necessary to overcome these practical problems and to develop technical solution that can keep the comfortable condition of tunnel environment during construction. In previous study, we have found that air leakage is the key factor in solving these problems and experimental results show that the new connection method has a leakage rate of about $1.46mm^2/m^2$ (Jo et al., 2017). In this study, we present the experimental results of the measurement of the leakage rate of the prototype with the new connection method, and analyze experimentally the improvement of the leakage rate when applying the flexible cover inside the duct to improve the leakage performance of the existing connection method.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2017.11a
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• pp.232-233
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• 2017

In this research, tunnel stern was applied on the asymmetric high-speed catamaran to evaluate vessel's hydrodynamic performance by numerical method, and the tunnel stern types are distinguished by angle of inclination of tunnel exit region into 3cases ($0^{\circ}$, $3^{\circ}$ and $6^{\circ}$). Consequently, it is confirmed that the total resistances of tunnel stern which have $0^{\circ}$ of inclination are lower about 4.8-17.9% than the bare hull in the wide speed range, but those of $3^{\circ}$ and $6^{\circ}$ of inclination tunnel stern are higher than bare hull about 5-14% and 5-29%, respectively. On the other hand, trim angles of $0^{\circ}$ of inclination tunnel stern show similar trend with those of bare hull in whole ranges of FnV but those of $3^{\circ}$ and $6^{\circ}$ of inclination tunnel stern are stabilized and declined respectively after FnV=1.54. These phenomena indicated that increasing angle of inclination of tunnel exit region had negative influence on resistance performance, however, it could make vessel's operation performance better than bare hull.

• Journal of the Korea Society of Computer and Information
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• v.16 no.9
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• pp.185-192
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• 2011

The purpose of this paper is to propose the design and implementation of a korean style internet-based test system on the basis of efficiency and stability for middle server. The current assessment system has some unstable elements with regard to transmission procedure, cost, system load and stability. This paper proposes a series of activities for the performance improvement of korean style internet-based test system which finally produced various excellent results in the administration of expense control, human resources, and special operational affairs. The proposed system's technological factors using middle server have been tested through a basic simulation pilot system. Actual development procedure starts from the analysis required by improving the shortcomings of existing internet-based test systems. A efficiency comparison with existing system and newly developed system was made in the area of number of operators, abnormal processing, system maintenances. Korean style internet-based test system using middle server has shown great efficiency increased to the maximum of 2 times about the effectiveness of processing for various parts. The korean style internet-based test system using middle server have been given good evaluations with regard to the convenience of their use and the management system for operators and supervisors.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.147-151
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• 2005

Retort pouch is widely used in food industry for a long-term preservation and safe food production. By applying retort pouch technique to waxycorn storage, the quality of waxycorn could be maintained and the storage expense could be saved during storage. Water activities(Aw) of retort waxycorn were below 0.80 except blanching treatment, and it is known that microbial propagation is subdued below 0.80. Commercial value of waxy corn was deteriorated when it was frozen quickly at $-40^{\circ}C$ before treating Retort due to obscurity of chromatocity, while the color change was not noticeable when it was treated with Retort at $121^{\circ}C$ for 10min. For all treatments, very small amounts of free sugar were detected, however, there were no significant differences between treatments. As storage period was longer, shelf lifes of waxy corn in control and waxy corn treated with blanching were more shortened when waxy corn was stored at $15,5^{\circ}C$ before Retort, while waxy corn with boiling treatment was not significantly different compared with that in storage in freezer.

• Food Science of Animal Resources
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• v.25 no.4
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• pp.383-390
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• 2005

To evaluate the sensory characteristics of domestic or imported chilled and frozen bellies, twelve samples were purchased and tested Sixty panels of sensory evaluation were consisted of six groups by sex and age. Frozen bellies were no difference in flavor, taste and tenderness. However, many panels favor the juiciness and acceptability of imported ones significantly compared to those of domestic ones(P<0.001). Especially, frozen bellies from northern America were tended to be more accepted than other products. The imported ones were significantly preferred to domestic ones irrespective of age. The results of sensory evaluation of frozen bellies between imported and domestic ones were also confirmed by tested people. It was significantly preferred in domestic frozen bellies(P<0.05). However, one of the domestic from C company was not significantly different from northern products, but was more favor significantly than EU ones(P<0.05). According to the age of tested panels, 20's age preferred the domestic ones of C company. In contrast, the groups of 30's and 40's age preferred the northern American produce.

• The Journal of Korean Society of Virology
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• v.30 no.3
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• pp.189-202
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• 2000

This study was conducted to see what types of bovine rotaviruses were isolated at Jedong farm in Jeju province and Seohwa farm in Chungnum province. The results were as follows. 1. Rotavirus was positively detected in 18 out of 39 fecal samples from calves with diarrhea in Jeju province and in 13 out of 18 fecal samples from calves with diarrhea in Chungnam province. 2. The electropherotype pattern of dsRNA for 31 viruses was shown to be 4 : 2 : 3 : 2 type like traditional group A and the imigration pattern of dsRNA was the long type like NCDV (G6), JBR (G6), B223 (G10) and KK3 (G10). 3. The serotypes of the 18 viruses of Jedong and 9 viruses of Seowha were shown to be group A, subgroup I, G6, and P1 by ELISA and PCR analyses. The serotypes of S-2, S-6, S-9 and S-12 viruses of Seowha were shown to be group A, subgroup I, G10, but was not shown to be P type. 4. The partial nucleotide sequence of VP4 of S-8 was 97% homology with that of BRV 033. VP4 of J-10 showed 96% homology with that of BRV 033 in nucleotide sequence.