• Journal of Navigation and Port Research
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• v.33 no.5
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• pp.345-352
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• 2009

The issues of environmental pollution and labor safety on ship recycling in the undeveloped countries such as India, Bangladesh, etc have been proclaimed. For this, IMO has been actively participated in resolving such problems since 1998 and then finally the International Convention for the Safe and Environmentally Sound Recycling of Ships is going to be adopted in this year. The convention provides the design, construction, operation and preparation of ships in order to facilitate safe and environmentally sound recycling as well as the safe and environmentally sound operation of ship recycling facilities. Therefore, the purposes of this study are to introduce the major contents of ship recycling convention and its time of entry into force and to analyse stakeholders' strategies toward it so that Korea will have a better position for the establishment of a mechanism regarding regulation stringency on environmentally sound ship recycling.

• Journal of the Korean Society of Hazard Mitigation
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• v.5 no.4 s.19
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• pp.95-105
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• 2005

Korea is located away from plate boundaries which are not safe from earthquakes. However, having witnessed the large-scale earthquake in the Tangshan region in 1976 deemed as a safe plate, it should not be assured that Korea is absolutely safe from earthquakes. In addition, many seismologists have claimed that there indeed is a high possibility of earthquakes above mid scale that would occur in Korea. Because it is impossible to prevent earthquake, studies on seismic design and earthquake disaster control system are widely being conducted. However, studies on early response to earthquakes or recovery process are still very limited, and only a few studies for establishing earthquake damage evaluation system are being conducted. Thus, this study aimed to present essential data for establishing earthquake damage evaluation system that takes into account the real situation of structures in Korea. In this study, a nonseimically reinforced concrete apartment structure in Gangnamgu was selected as an standard type of such structures and its earthquake damage was estimated. The result of damage evaluation based on the derivation of vulnerability function and realtive story displacement was compared to that abtained using HAZUS Program Vulnerability Function.

• Journal of the Korean Institute of Gas
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• v.20 no.1
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• pp.29-39
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• 2016

Electrical apparatuses for use in the presence of explosive gas atmospheres have to be special designed to prevent them from igniting the explosive gas. Flameproof design implies that electrical components producing electrical sparks are contained in enclosures and withstand the maximum pressure of internal gas or vapours. In addition, any gaps in the enclosure wall have to designed in such a way that they will not transmit a gas explosion inside the enclosure to an explosive gas or vapours atmosphere outside it. In this study, we explained some of the most important physical mechanism of Maximum Experimental Safe Gap(MESG) that the jet of combustion products ejected through the flame gap to the external surroundings do not have an energy and temperature large enough to initiate an ignition of external gas or vapours. We measured the MESG and maximum explosion pressure of propane and acetylene by the test method and procedure of IEC 60079-20-1:2010.When the minimum MESG is measured, the concentration of propane, acetylene in the air is higher than the stoichiometric point and their explosion pressure is the highest value.

• Journal of the Korean Institute of Gas
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• v.17 no.5
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• pp.37-41
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• 2013

This paper presents the strength safety of stress and deformation behaviors using the finite element method as a function of the thickness of the protective helmets with and without an extruder on the top of the shell structure. The helmet that would provide head and neck protections without causing discomfort to the user when it was worn for long periods of time should be manufactured for increasing the safety and impact energy absorption. The stress analyzed results show that when the impulsive force of 4,540N is applied on the top surface of a helmet, the safe thickness is 3.7mm for the conventional helmet and 3.2mm for the modified new helmet. Based on the deformation analysis, the FEM results recommend that the safe thickness is 3.2mm for the conventional helmet and 2.0mm for the modified new helmet. Thus, it may be more safe design of the helmet, which has an extruded structure on the summit surface of the helmet.

• Journal of Industrial Convergence
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• v.21 no.7
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• pp.41-49
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• 2023

In recent years, various educational institutions have used online certificate services to verify academic achievement related to graduation and grades. However, the certificate of the existing system has limitations in verifying and tracking whether it is true or not and detailed academic background. In this regard, cases of forgery/falsification of online/offline certificates continue to occur. This study proposes a blockchain-based verification method that is safe from forgery and alteration, focusing on university institutions. Necessary information such as detailed class categories for each department, attendance, and detailed grades was collected/analyzed to create a linkage relationship through blockchain. In addition, the system/network environment required for blockchain sharing was considered, and it was implemented as an extension module in the form of an independent web application. As a result of the block chain verification, it was proved that the safe trust verification of educational information and the relationship between detailed information can be traced. This study aims to contribute to the improvement of academic credential verification services and information security for Korean educational institutions in the future.

• Journal of Aerospace System Engineering
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• v.14 no.3
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• pp.42-50
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• 2020

For calibration of the non-uniformity characteristics of the space-borne infrared (IR) sensor, a black body system shall provide estimated representative surface temperature at various reference temperatures by using the limited number of temperature sensors. The black body system proposed in this study has an I/F flange integrated on the rear side of the black body for installation of the heat pipe to transfer the residual heat after the black body heat-up. This design allows for obtaining a circular symmetric thermal contour of black body with low surface temperature gradient, leading to much easier representative temperature estimation. Additionally, this provides mechanically stable thermal I/F under launch and on-orbit environmental loads, as well as allowing a fail safe design by using the two heat pipes. Also, a highly accurate temperature estimation is possible even if the temperature sensors are attached on the surface on the rear side of the black body. The effectiveness of the thermal design of the proposed black body has been verified through the on-orbit thermal analysis. Based on the results, the representative surface temperature was estimated according to the number and position of the temperature sensors.

• Journal of Energy Engineering
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• v.5 no.2
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• pp.146-152
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• 1996

A small power reactor core of 108 MW$\_$th/ was designed with some design constraints: 2 year refueling cycle length, soluble boron free operation, low power density, and proven fuel assembly design - Uljin 3'||'&'||'4 design specifications. CASMO-3 and KINS-3 was used to evaluate operational capability for power level control via control rods. Cycle length, power peaking factor, M.T.C., and power coefficients were also checked. Designed core loaded with KOFAs satisfied all design goals. We found that much more burnable poisons are to be loaded with axial enrichment zoning. Control rod assemblies should be located at every other assemblies with more than 3 banks. Additional shutdown banks are proposed for the safe plant cooldown, which could be located at core periphery.

• The Korean Journal of Applied Statistics
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• v.33 no.2
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• pp.137-145
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• 2020

Phase I clinical trials (Dose Finding Studies) are the first step in administering new drugs developed through animal experiments or in vitro experiments to humans. An important area of interest in designing Phase I clinical trials is determining the dose that provides the greatest efficacy and acceptable safe dose to the patient. In this paper, we propose a method to determine the maximum tolerated dose considering efficacy and safety using Biased coin design and stopping rule. The proposed method is compared with existing methods through simulation.

• Journal of the Korean Institute of Gas
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• v.7 no.3 s.20
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• pp.58-64
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• 2003

This paper presents design safety analysis of pressure vessels. The gas pressure and thermal loads are applied to the pressure vessel simultaneously. In this study, ASME Sec. VIII Div. 2 code was accepted for the safety design of high-pressure vessel. And this result was analyzed using a coupled thermal-mechanical FEM analysis technique. The FEM computed result shows that ASME design code may not guarantee for combined loads of high gas pressure and thermal loads. And solid pressure vessel may be safe compared to other pressure vessels with supporting rings round the cylinder body.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2004.11a
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• pp.237-240
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• 2004

Sulfur Hexafluoride, SF6 is widely used for leak detection and as a gaseous dielectric in transformers, condensers and circuit breakers. SF6 gas is also effective as a cleanser in the semiconductor industry. This paper presents a numerical study of the sealing force of disk type seal in SF6 gas safety valve. The sealing force on the disk seal is analyzed by the FEM method based on the Taguch's experimental design technique. Disk seals in SF6 gas safety valve are designed with 9 design models based on 3 different contact length, compressive ratio and gas pressure. The calculated results of Cauchy stress and strain showed that the sealing characteristics of Teflon PTFE is more effective compared to that of FKM(Viton), which is related to the stiffness of the materials. And also, the contact length of the disk seal is important design parameter for sealing the SF6 gas leakage in the safety valve.