• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.480-484
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• 2008

셀렝게(Selenga)강은 몽골에서 발원하여 세계최대의 담수호로 알려진 러시아 바이칼호로 유입되는 국제하천으로서 소비에트 연방해체 이후 계획경제가 무너지면서 다양한 물환경문제에 노출되어 있다. 몽골의 경우 도시개발이 급격히 진행되고 있으나 처리시설의 미비로 인한 오폐수 배출 및 무분별한 광산개발에 따른 수질오염문제가 현안이 되고 있으며, 러시아(브리아트공화국)는 계획경제의 붕괴에 따른 산업구조의 변화, 처리시설의 부족 및 운영의 비효율성, 산림자원의 개발에 따른 비점오염부하의 증가 등의 수질문제 해결이 요구된다. 몽골은 자연적인 특성상 광물질을 많이 포함하는 지표수 성상 및 매우 적은 강우량으로 인한 수자원의 부족, 지역별로 극심한 물공급량의 불균형, 산업개발에 따른 지하수 오염 등의 문제를 포함한 수자원 부족이 해결해야할 현안과제이고, 러시아는 수자원은 매우 풍부하나 공급시설의 낙후 및 비효율적인 운영으로 인한 물 공급 시스템의 개선이 절실히 요구되는 상황이다. 물 환경관리 체계를 보면 양국 공히 대내적으로는 이용 및 공급 주체별로 분화된 물 관리체제로 인해 부문간 통합성이 결여되어 있으며, 대외적으로는 셀렝게강 상 하류 물이용 개발, 수질보전 및 수생태계보호와 연관된 문제해결을 위한 몽골과 러시아간의 국제적인 협력시스템이 없는 실정이다. 경제개발에 따라 최근 수질오염 및 물이용 개발과 관련된 이해당사자 간의 갈등이 심화되고 있어 이를 지역, 국가, 국제적인 차원에서 조정할 수 있는 통합관리시스템의 구축과 이해당사자의 인식제고 및 자체적인 관리능력 배양을 위한 역량강화프로그램의 개발 운영이 요구되고 있다. 따라서 본 연구에서는 동지역에서 기초현황조사, 물 환경현안 파악, 물 관리정책 및 체계와 문제점을 파악하고 향후 DPISR(Drivers-Pressures-Impact-State- Response) 분석이 가능하도록 물환경관리와 연관된 물환경상태, 현안, 원인, 영향 및 대책을 종합적인 관점에서 분석하며, 해외의 주요 국제하천의 물 환경관리모델에 대한 사례분석 및 비교연구를 통해 물이용 및 개발과 관련된 이해상충 조정체계를 개발하고자 하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.1
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• pp.103-111
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• 2021

Naju Seokdanggan, Treasure No. 49, was dismantled and reconstructed due to poor performance. During construction, the crack area was reinforced and the inclination was improved. It is necessary to analyze the stiffness changes before and after the reconstruction of these cultural properties, and to establish a database of related information. In addition, there is a need for research on a scientific non-destructive testing method capable of predicting or evaluating the reinforcing effect. In this study, a simple equation for estimating the overall stiffness of the structural system was derived from information on the elasticity coefficient and the natural frequency measured by vibration tests before and after reconstruction work, and the applicability of the equation was examined. If the stiffness of important cultural properties is regularly investigated by the suggested method, it is judged that it can be used as data to estimate the time when structural safety diagnosis is necessary or when repair or reinforcement is necessary.

• Explosives and Blasting
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• v.28 no.2
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• pp.59-68
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• 2010

Building demolition and blasting work in urban areas has a possibility which has an effect on the structural stability of nearby structures. In this study, the compressive strength and chemical composition of decrepit concrete materials were estimated by Schmidt rebound test and XRD phase analysis. The damage index of the concrete materials was calculated by measured P-wave velocities. It was revealed that the constituents of the concrete materials affect on the compressive strength. The damage index decreases with increasing compressive strength and decreasing impact energy.

• Korean Journal of Construction Engineering and Management
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• v.11 no.6
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• pp.89-99
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• 2010

Military Barracks and Bachelor Officer's Quarters are public buildings representing architectural characteristics with repeating the same room modules. These buildings require easy dismantling and reusing for the next generation' military re-organization. For these reasons, since 2005, the modular construction has been applied to military buildings. The most important factors required for modular military buildings are standardization, lowcost construction and reusable construction method. However, conventional modular building system have not been matched with these requirements. This study suggests a new modular system for Bachelor Officer's Quarters using Six-sigma design tool. To reflect the voices of customers, market study and surveys were carried out. Through the QFD, the voices of customers were converted into quality characteristics of building system for BOQ. The various design concepts meeting customer's requirement were derived by the QFD and Pugh matrix methodology. The proposed modular building system shows 80% increased factory production rate and 62% decreased weight of steel frame as compared with the conventional modular building system.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.23-24
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• 2023

In this study, an easily recyclable separable glued-laminated timber (GLT)-steel beam was developed, and a structural design method was presented. The GLT and steel were mechanically composited using self-tapping screws. The GLT-steel beam was designed to fail in the compression of GLT. The bending moment and load-carrying capacity of the GLT-steel beam were predicted based on composite beam theory and compared with experimental test data. As a result, the GLT-steel beam exhibited ductile behavior, and compression failure of GLT was observed. The screw connection showed no damage while the steel plate was extended. The load-carrying capacity of GLT after failure was similar to the load resistance predicted by the compressive strength of GLT and the tensile strength of steel. This indicates that the ductile behavior of the GLT-steel beam can be safely designed by the tensile strength (yield) of steel.

• The magazine of the Korean Society for Advanced Composite Structures
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• v.5 no.2
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• pp.26-31
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• 2014

This invention is purposed to provide an innovative solution for the inside of roof structures, which is cultural assets. The Asian old houses generally have several layered roofs on top of the structures. If a fire has started inside of the roof, it is hard to be extinguished before eliminating all the upper layers of the roof. This invention provides pre constructed embedded pipes, which is flammable and easy to be dissolved by the fire. The material of pipe is composed of rubbers, of which the combustion point is so low that the extinguishing of initial fire is possible without additional fire service. The inside of pipe is filled with halon gas. If the filled gas is consumed after ignited by fire, additional fire extinguishing water is supplied. If the flexible pipes are totally combusted by a big fire, the sprinkler at the end of inflexible pipe will work continuously, which is located between flexible and inflexible pipes. The extinguishing pipe network is suggested as dividing whole roof as multiple sections for a swift fire extinguishing in case of intentional or natural fire attack to our invaluable cultural assets.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.343-356
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• 2016

The Korea Radioactive Waste Agency (KORAD) has developed a dual-purpose metal cask for the dry storage of spent nuclear fuel that has been generated by domestic light-water reactors. The metal cask was designed in compliance with international and domestic technology standards, and safety was the most important consideration in developing the design. It was designed to maintain its integrity for 50 years in terms of major safety factors. The metal cask ensures the minimization of waste generated by maintenance activities during the storage period as well as the safe management of the waste. An activation evaluation of the main body, which includes internal and external components of metal casks whose design lifetime has expired, provides quantitative data on their radioactive inventory. The radioactive inventory of the main body and the components of the metal cask were calculated by applying the MCNP5 ORIGEN-2 evaluation system and by considering each component's chemical composition, neutron flux distribution, and reaction rate, as well as the duration of neutron irradiation during the storage period. The evaluation results revealed that 10 years after the end of the cask's design life, $^{60}Co$ had greater radioactivity than other nuclides among the metal materials. In the case of the neutron shield, nuclides that emit high-energy gamma rays such as $^{28}Al$ and $^{24}Na$ had greater radioactivity immediately after the design lifetime. However, their radioactivity level became negligible after six months due to their short half-life. The surface exposure dose rates of the canister and the main body of the metal cask from which the spent nuclear fuel had been removed with expiration of the design lifetime were determined to be at very low levels, and the radiation exposure doses to which radiation workers were subjected during the decommissioning process appeared to be at insignificant levels. The evaluations of this study strongly suggest that the nuclide inventory of a spent nuclear fuel metal cask can be utilized as basic data when decommissioning of a metal cask is planned, for example, for the development of a decommissioning plan, the determination of a decommissioning method, the estimation of radiation exposure to workers engaged in decommissioning operations, the management/reuse of radioactive wastes, etc.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.3
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• pp.75-82
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• 2010

The static strengths of the existing RC beams were experimentally investigated in this paper to understand the strength characteristics of existing structural members and to get appropriate data in strengthening RC members in the remodelling construction. Ten RC beams were prepared by cutting and extracting directly from the demolition site of apartment housings and tested in order to evaluate the flexural and shear strengths of existing RC beams by their geometric condition. From the test results, it was found that most of the specimens had a sufficient structural capacity except for some special case, for example, specimens with severe cracks or concrete losses caused by improper casting. Therefore, the severely deteriorated members originated from bad concrete casting or careless construction process should be repaired and strengthened in remodelling construction.

• Journal of Korean Society of Steel Construction
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• v.13 no.4
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• pp.337-349
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• 2001

This study present an optimum deck and girder system design for minimizing the life-cycle cost (LCC) of orthotropic steel deck bridges. The problem of optimum LCC design of orthotropic steel deck bridges is formulated as that of minimization of the expected total LCC that consists of initial cost, maintenance cost, expected retrofit costs for strength, deflection, and fatigue. To demonstrate the effect of LCC optimum design of orthotropic steel deck bridges, the proposed optimum LCC design is compared with the conventional method for orthotropic steel deck bridges design. From the numerical investigations, it may be positively stated that the proposed optimum design procedure for orthotropic steel deck bridges based on the LCC will lead to more rational, economical and safer design.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.1
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• pp.121-133
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• 2020

Underwater cutting has a different mechanism than dry cutting, and there are more restrictions than benefits. Due to these constraints, research and development of underwater cutting has been very limited. At present, reactor dismantling is emerging as an important task worldwide, and reactor pressure containers, a key part of the reactor, are decommissioned based on underwater cutting. Reactor pressure containers are high-level radioactive waste, which is one of the main goals of today, such as to bridge the gap between environmental, safety, and cutting performance; hence, a process suitable for cutting should be applied. Therefore, many studies are being conducted on underwater cutting in connection with the dismantling of nuclear reactors in various areas in order to find appropriate processes. This paper first introduces the core technology of underwater cutting processes and discusses various processes. The emphasis is then placed on the adequacy of the reactor dismantling application. More specifically, we examine the suitability for the mechanical and thermal cutting processes, respectively, to find a solution suitable for dismantling a reactor. We discuss how each solution can sufficiently perform the specified functions at each stage of reactor dismantling and suggest that these processes can perform all of the work of underwater cutting.