• Proceedings of the Korean Nuclear Society Conference
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• 1996.05d
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• pp.176-181
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• 1996

원자로 용기 헤드부위의 관통관은 재질이 Inconel-600이며, 현재 세계각국에서도 원자로 헤드 관통관의 균열이 일부 발견되어 우리나라에서도 관심이 되고 있다. 국내 원전 헤드관 통관 수량도 고리 1,2호기의 경우 40개, 고리3,4호기(영광1,2) 61개, 울진 57개로서 관통관의 균열결함이 존재할 수 있다. 만약 균열이 성장하여 파손 되었을 시 원자로 냉각재 누설등 발전소 안전에 큰영향을 미치므로 균열의 원인으로 알려진 용접부위 잔류응력 및 발전소 정상운전 상태에서의 응력을 해석하였다.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.05a
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• pp.203-208
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• 2002

일반적으로 탄화수소를 비롯해 가연성물질은 쉽게 연소하거나 폭발한다. 특히 가스는 공정에서 가연성물질을 취급에 있어 밸브의 조작실수, 배관접합부파손 등으로 인해 누출된 물질이 주위에 공기와 혼합하여 착화원에 의해 화재 및 폭발이 발생할 수도 있으며, 또한 유해물질 상태로 유출되어 인명에 피해를 주는 경우도 있다. 산업현장에서 화재 및 폭발의 위험을 최소화하기 위해서는 공정의 안전과 최적화 조작이 이루어 져야 하는데, 이를 위해 우선 작업 조건 하에서 취급물질의 연소 특성치 파악이 필요하다/sup 1)/.(중략)

• 한국문화재보존과학회:학술대회논문집
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• 2002.11a
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• pp.31-40
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• 2002

1. 프랑스의 문화재보존과 복원 연구소 조직 현황소개 2. ARC-NUCLEART연구소 소개-연구소에서 문화재 보존을 위해서 사용 기술소개 - 지상과 해양의 고고학 발굴시 젖은 목재와 가죽작품 건조작업, 강화작 업, 보수작업 수행 -목재문화재 (조각상, 가구, 사적 바닥마루), 멸균 및 강화처리 - 가죽문화재의 복원 3. 연구소 시설 4. 화재 자질의 파손상태파악과 고고학가치의 목재와 가죽작품 보존 방법에 대한 연구 수행 5. ARC-NUCLEART에서 보존, 복원하는 문화재의 처리 용례 아크 뉘클레아르(ARC Nucleart)의 감마선조사기 설치

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.314-321
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• 2016

Adapting the maintenance criteria of Seoul City pavement is not applicable for borough pavement due to differences between the pavement of Seoul city and the borough, such as priority of maintenance, traffic volume, thickness of pavement, and pavement deterioration rate by distresses. To develop an efficient and reasonable evaluation method of the Seocho borough pavement condition within a limited budget, this study suggested the borough pavement condition evaluation model based on the PMS (Pavement Management System) of Seoul Metropolitan SPI (Seoul Pavement Index). The SPI was modified to predict the remaining life and determine the proper maintenance method for the pavement in Seocho borough. This was suggested to reflect the rate of the designed performance life and field performance life of pavement as well as the pavement condition at the stage of the completion of construction. Primary variables, such as crack, rutting and IRI in the final model affect the overall performance life due to their even composition. Therefore, the suggested model considering the lowered criteria, design performance factor, and construction factor can be used for the more efficient maintenance of Seocho borough pavement.

• Journal of Conservation Science
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• v.29 no.2
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• pp.161-170
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• 2013

The purpose of this study is to find the reasonable plan for the restoration method through the practical repair of excavated costume. The minimal repair only without adding the physical force as far as possible after investigating the state of excavated costume has been progressed in case of excavated costume since it is already degraded and weak due to the characteristics of organic matter at the moment when it is excavated. Moreover, it has been restored as the following course; The restoration has been applied according to the state of excavated costume with the maximum stability by classifying items capable of being restored considering the fabric state of excavated costume. The drawn thread from the weak in strength and the refined thread of the Juasa(simple gauze) or the light degraded silk thread has been used in case of thread for restoration. The cotton fabrics has been used in the fabric of cellulose system, the Juasa or the silk has been used in the silk depending on the kind of fabric in connection with the support fabric, some parts have been dyed with Alnus firma fruit and the persimmon, has been repaired by using the dyed fabric with the clove for the purpose of mothproof-antibacterial treatment. The method to repair has been carried out by classifying according to the state of damage and the way of formation of costume. The needlework method suitable for the part and state of damage by using the basting, the broad-stitching, backstitch, the blind stitch and the hemming stitch in connection with the needlework method for restoration.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.167-174
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• 2009

The simulation of dynamic load was conducted based on surface profile on asphalt concrete pavement, vehicle speeds, and suspension types using a truck simulation program. The results of the simulated dynamic load based on different surface profile, vehicle speeds, and suspension types are analyzed. As pavement roughness and vehicle speed are increased, the dynamic load was increased. Walking beam suspension produces greater dynamic load than air spring suspension. Pavement damage index is calculated based on covariance of dynamic load and Paris-Erdogan fracture parameter, n which is based on creep compliance tests of asphalt mixtures used in Korea. The higher covariance of dynamic load, confidence level, and fracture parameter are used, the greater pavement damage index is obtained. Specification of pavement roughness can be developed in various vehicle speeds and asphalt mixtures, and pay factor can be determined after constructing asphalt concrete pavement using pavement damage concepts.

• Composites Research
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• v.14 no.6
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• pp.16-23
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• 2001

Analysis of mechanical behavior for a pultruded-wound hollow rod is presented. For this purpose, the pultruded-wound hollow rod is manufactured by the new winder attached to the conventional pultrusion system. And the conventional pultrusion process is newly altered to manufacture pultruded-wound specimens. A computer program, POST II, is modified to perform this study, In the nonlinear finite element formulation, the updated Lagrangian description method based on the second Piolar-Kirchhoff stress tensor and the Green strain tensor are used. For the finite element modeling of the composite hollow rod, the eight-node degenerated shell element is utilized. In order to estimate the failure, the maximum stress criterion is adopted to the averaged stress in the each layer of the finite elements. As numerical examples, the behavior of glass/up composite hollow rod is investigated from the initial loading to the final collapse. Present finite element results considering stiffness degradation and stress unload due to failure shows excellent agreement with experiments in the ultimate load, failure and deformations.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.3
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• pp.603-610
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• 2017

Various type of pavement deterioration such as crack, bumpy, pothole is rapidly increasing according to the accelerated environmental changes like heavy rainfall, frequent snowing, difference temperature, etc. Accident related to pothole that cause fatal traffic accidents has been increased more than five times over the next five years starting from 2008. As direct or indirect damage by pothole which caused injuries and car damages increases every year, quicker and more efficient management measures are necessary. This study presents the algorithm for materials quantity take-off. The algorithm was suggested by correlation in pothole size and area. Suggested algorithm were confirmed the validity through the 15 field survey in capital area. According to the results of survey, usually the residual materials at which 5~7 kg was generated decreased to 1~2 kg. It showed that automatic pothole detection system is expected not only to reduce materials and resources, but also to contribute to quality improvements of pavement through more accurate material take-off from the situation of constructing rely on their own judgement.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.30 no.8
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• pp.103-111
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• 2002

Steady-state creep analysis of power generation turbine blade is carried out considering thermal loads and centrifugal forces. Creep strains and stresses of the turbine blade are calculated for 3-D finite clement model of the turbine blade. From the numerical results, creep life of the turbine blade is predicted. The results of creep analysis during about 200 hours indicate that creep strains of the turbine blade do not reach the rupture strain of GTD111. Creep stresses of the turbine blade are relaxed as time increases. Maximum creep strain occurs at the tip section of the airfoil pressure surface. The maximum creep strain of the turbine blade is expected close to the rupture strain after 50,000 hours approximately. The turbine blade may not have creep damage for the starting procedure of the turbine.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.7
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• pp.592-600
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• 2007

Nowadays, researches for replacing material systems for cryotanks by composites have been being performed for the purpose of lightweight launch vehicle. In this paper, a type 3 propellant tank, which is composed of the composite developed for cryogenic use and an aluminum liner, was fabricated and tested considering actual operating environment, that is, cryogenic temperature and pressure. For this aim, liquid nitrogen (LN2) was injected into the fabricated tank and in turn, gaseous nitrogen (GN2) was used for pressurization. During this test procedure, strains and temperatures on the tank surface were measured. The delamination between hoop layer and helical one, was detected during the experiment. Several attempts were followed to investigate the cause analytically and experimentally. Thermo-elastic analysis in consideration of the progressive failure was done to evaluate the failure index. Experimental approach through a LN2 immersion test of composite/aluminum ring specimens suitable for simulating the Type 3 tank structure.