• Journal of Ocean Engineering and Technology
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• v.11 no.3
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• pp.8-19
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• 1997

In this study an adequate type of offshore structure at the Sakhalin region as cold region is proposed and its structural design results are presented based on the reliability analysis. Structural safety assessment has been carried out for the proposed offshore structure at the Sakhalin area as designed by the reliability method. And a rational design procedure is presented based on the reliability analysis. Followings are drawn through the present study : - Four colum TLP structure is proposed as an adequate offshore structure type at the cold region like the Sakhalin region and the reliability-based structural design results are presented. It is seen that the proposed type is a more adequate and economic than the fixed type. - Safety assessment of the proposed structure applying the extended incremental load method is performed. - Referring the allowable safety level for offshore structures it has been found present TLP structure has sufficient structural safety at the system level as well as at the component level.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.4
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• pp.171-180
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• 2000

This study aims to present a more reasonable control value than the exiting one by comparing and analyzing control values and field instrumentation values of the whole excavation depth of the four case sites using geometric averaging as a statistical method. The range of the study is confined to three things: (1) the axial force of the braced excavation walls among a variety of items prescribed in the control values by stress deformation of walls and adjacent structures; (2) by approximation of the allowable and design value; (3) and by safety factor. As a res it is desirable to revise "(Long term allowable stress + Short term allowable stress)/2 ~ Short term allowable stress," presented in the present control values by stress deformation of walls and adjacent structures, to "(Long term allowable stress + Short term allowable stress)/5 ~ (Short term allowable stress)/3." The result also shows that since there is a difference of about 3.5%, it is not necessary to revise 70, 90, and 100 percent of LEVEL I, II, and III, prescribed in the control values by the allowable and design value approximation. In addition, modifying the control value by the safety factor, now 1.07, is unnecessary, although it varies little difference from the present value.

• Journal of the Korean Society of Safety
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• v.30 no.3
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• pp.67-72
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• 2015

Although attention to terrorism has increased sharply in recent years within many countries, it is by no means a new phenomenon. Majority of these countries have limited regulations or guidelines about terrorism. LOP (Level Of Protection) can be consider as a first step. This paper seeks to present a process to determine LOP and allowable damage. LOP is determined by asset value reason why it should be based on cost. The asset value is defined as "cost induced when asset is damaged". For example, the collateral damage outside the facility should be taken in consideration in the asset value. Allowable structural damage is assigned depending on LOP.

• Journal of the Korean Society of Safety
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• v.33 no.2
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• pp.145-151
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• 2018

In this study, the track-bridge interaction analysis was performed using an analytical model considering the track structure, thereby taking into account the linear conditions (R=650 m, cant variation $160{\pm}60mm$) and the dynamic characteristics of the bridge. As a result of the study, the allowable speed on the example bridge considered was calculated at 200 km/h based on vertical deflection, vertical acceleration, and irregularity in longitudinal level, but was also evaluated at 170km/h based on the coefficient of derailment, wheel load reduction, and lateral displacement of the rail head. It is considered desirable to set the speed 170km/h to the speed limit in order to secure the safety of both the bridge and the track. It is judged that there will be no problems with ensuring rail protection and train stability in the speed band.

• Journal of Wellbeing Management and Applied Psychology
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• v.4 no.2
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• pp.19-25
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• 2021

Purpose: The purpose of this study is to reduce odor complaints by identifying problems with odor management at the site of the water regeneration center and researching odor management methods. Due to the high population density of Korea, sewage treatment facilities are adjacent to residential and industrial areas. According to previous studies, the main malodor-emitting facilities of sewage treatment facilities were preliminary treatment facilities (2,220 times), sedimentation basins (4,628 times), and sludge treatment facilities (9,616 times). Research design, data and methodology: Compound malodors and designated malodor-producing substances were collected from five site boundaries of the water regeneration center and analyzed according to the official methods to test malodor, and a total of two times (August and September 2020) were conducted. Results: As a result of the measurement, in the green area in front of the center office, compound malodors were detected at a maximum of 8 times and at least 3 times during the dawn time. As for the designated malodor-producing substances, 0.1ppm of ammonia was detected in the green area in front of the center office and the park golf course. This is within 15 times the maximum allowable emission level of compound malodors and within 1ppm of the maximum allowable emission level of ammonia. Conclusions: Even if the dilution rate of the compound malodors did not exceed the maximum allowable emission level, the odor could be recognized, and more research is needed in the future to establish effective reduction measures according to the subjective and individual and seasonal odor characteristics.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.4
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• pp.169-176
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• 2001

This study aims to present a more reasonable control value than the exiting one by comparing and analyzing control values and field instrument8tion values of the whole excavation depth of the four case sites, using geometric averaging as a statistical method. The range of the study is confined to the horizontal displacement of braced excavation walls among a variety of items, prescribed in the control values by approximately of the allowable and design values, and by safety factors. As a result, it is desirable to revise 70, 90, and 100 percent of LEVEL I, II, and III, respectively. The horizontal displacement values of the allowable and design values approximations should change to 104, 133, and 148 percent of the allowable and design values, respectively. In addition, modifying the horizontal displacement control value of the braced excavation walls is not needed. The horizontal displacement value, presented in the control value as a safety factor, is now 1.19, as it has a slight difference from the present value.

• Journal of the Korean Society of Safety
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• v.27 no.6
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• pp.14-19
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• 2012

The Helium cooled ceramic reflector(HCCR) test blanket module(TBM) has been designed and developed to participate the ITER(International Thermonuclear Experimental Reactor) test blanket program in Korea. The TBM was one of the main objectives for developing ITER for proving the tritium self-sufficiency and the heat transfers to produce the electricity with the breeding blanket concept. Among the TBM components, the first wall(FW) was the most important component in safety since it was directly faced a high level of a heat and fast neutrons from the plasma side and could protect the others components inside TBM. In this paper, the FW has been designed through the thermo-mechanical analysis considering ITER operation conditions. With the developed simple models, the stress limit analysis based on RCC-MR code which is the nuclear power plant design codes in France was evaluated for the allowable design criteria. The results showed that the designed FW model satisfied $1.5S_m$ or $3S_m$ of the allowable stress($S_m$) in RCC-MR code at the maximum stress region in the FW.

• Explosives and Blasting
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• v.31 no.2
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• pp.50-58
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• 2013

Since various types of safety facilities have been located around blasting construction site, each of the institutions with regard to blast works has prepared limit criterion of blast vibration, respectively. But these criterions applied for limiting vibration are causing harmful effect including construction cost increasement and construction time extension due to exceedable high level application. In this study, more reasonable limit of blast vibration was suggested after reviewing criterions based on existing design and construction cases and analyzing of problems of applied criterions.

• Fire Science and Engineering
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• v.27 no.5
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• pp.26-31
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• 2013

In nuclear power plant, anchor bolts for pressurizer supports are sufficiently used in terms of safety reason, but field inspections have reported that some bolts exceed the limit of their allowable hardness. Because the high level of hardness may lead to failures due to the stress corrosion or fracture toughness, a regular inspection is required for the bolts in nuclear power plant. Thus, this research measures the hardness of bolts currently used in pressurizer supports and then estimates maximum allowable stresses preventing failures by stress corrosion and fracture toughness. Using the ANSYS program, the stresses of the bolts in the regular condition and accidental condition have been calculated, and the possible maximum stress has been compared with the estimated allowable stresses. From the results, the stresses of bolts in the accidental condition satisfy the allowable safety stress from the stress corrosion failure. However, in the future, it shall be needed to consider the reflection of the structure assembling method on the assembling procedure to ensure the pressurizer integrity during maintenance period time.

• Journal of the Korean Institute of Gas
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• v.4 no.1 s.9
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• pp.9-15
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• 2000

In order to investigate the structural defects of a cylindrical-type toluene storage tank, we carried out the acoustic emissions. The storage tank was manufactured with high strength steel in 1978 and its's first and second courses from bottom were entirely repaired, recently. Acoustic emissions were monitored with real time according to load sequences in the $75{\~}84\%$ level range of maximum allowable load. Our results show a non-genuine acoustic emissions as well as a genuine characteristics. The pseudo emissions considered as valve noises were transiently occurred on shut-off processes of inlet valve regardless of water loading. The acoustic emission events occurred during water filling phase were estimated due to defects, and in the $75{\~}84\%$ test load level no evidences of defect growth were observed. Those defects were ascertained as weld cracks and porosities through the post radiography testing conducted near active sensors.