• 비파괴검사학회지
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• 제11권1호
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• pp.52-60
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• 1991

The importance and role of preservice and inservice inspection(PSI/ISI) for nuclear power plant components are intimately related to plant design, safety, reliability and operation etc.. The Korea Atomic Energy Research Institute(KAERI) has been performing PSI/ISI in Korea since the PSI of Kori nuclear power plant, unit 1 had been performed in 1977. KAERI has localized PSI/ISI technology and has done much experience in ultrasonic flaw detection, evaluation and its excavation on the weldments of large pressure vessels. The results of flaw estimation using ultrasonic examination are compared with the actual flaw sizes revealed by field excavation. KAERI's experience regarding PSI/ISI was described and some discussions were added.

• Ecology and Resilient Infrastructure
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• 제3권3호
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• pp.162-168
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• 2016

본 연구는 국내의 대표적 로드킬 동물인 고라니 (Hydropotes inermis)의 연간 로드킬 발생건수를 추정하고자 하였다. 이를 위해 국내의 도로 통계와 로드킬 통계 자료를 분석하고, 국외의 사슴류 로드킬 발생건수에 관한 추정 사례를 검토하여 국내의 고라니 로드킬 추정 방법에 적용하였다. 연구결과 국내에서 고라니 로드킬은 연간 최소 6만 건 이상 발생하는 것으로 추정되었다.

• 한국해양공학회지
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• 제8권1호
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• pp.41-49
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• 1994

The leak-before-break(LBB) design on the large structures such as ship's hull, tank structure, pressure vessels etc. is one of the most inportant subjects for the evaluation and the assurance of safety. In these structures, various loads are acting. In some structural members, therefore, out-of-plane stress due to bending often may become with in-plane stress due to stretching. In the present report, the characteristics of fatigue life and peneration behaviour from a surface cracked plate under combined tension and bending have been studied experimentally and analytically by using eccentricity. Estimation of fatigue crack growth was done with the Newman-Raju formula before penetration, and with the stress intensity factor after penetration proposed by the author. Calculated aspect ratio showed the good agreement with the experimental result. It was also found that particular crack growth behaviour and crack shape after penetration can be satisfactorily evaluated using the K solution proposed.

• 전기학회논문지
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• 제66권9호
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• pp.1416-1423
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• 2017

Lane detection technology is one of the most important issues on car safety and self-driving capability of autonomous vehicle. This paper introduces an accurate lane detection scheme based on OCC(Optical Camera Communication) for moving vehicles. For lane detection of moving vehicles, the streetlights and the front camera of the vehicle were used for a transmitter and a receiver, respectively. Based on the angle information of multiple streetlights in a captured image, the distance from sidewalk can be calculated using non-linear regression analysis. Simulation results show that the proposed scheme shows robust performance of accurate lane detection.

• Journal of Information Processing Systems
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• 제13권2호
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• pp.285-304
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• 2017

Big data information and pattern analysis have applications in many industrial sectors. To reduce energy consumption effectively, the eco-driving method that reduces the fuel consumption of vehicles has recently come under scrutiny. Using big data on commercial vehicles obtained from digital tachographs (DTGs), it is possible not only to aid traffic safety but also improve eco-driving. In this study, we estimate fuel consumption efficiency by processing and analyzing DTG big data for commercial vehicles using parallel processing with the MapReduce mechanism. Compared to the conventional measurement of fuel consumption using the On-Board Diagnostics II (OBD-II) device, in this paper, we use actual DTG data and OBD-II fuel consumption data to identify meaningful relationships to calculate fuel efficiency rates. Based on the driving pattern extracted from DTG data, estimating fuel consumption is possible by analyzing driving patterns obtained only from DTG big data.

• Asian Journal of Atmospheric Environment
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• 제4권1호
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• pp.20-25
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• 2010

The gaseous $^{222}Rn$ concentration at the level of clouds was estimated by using the wet scavenging model of its decay products with the observed data of environmental radiation at the ground. And the origin of the $^{222}Rn$ was also discussed. The estimation was done for a precipitation event on Dec. 26-27, 2003, when a large increase of the radiation was observed in Tokai-mura in Ibaraki, Japan. From a backward trajectory analysis, the origin of $^{222}Rn$ atoms for that event was traced back to the northeastern part of China, and it was expected that the large amount of $^{222}Rn$ emitted in the northeastern part of China was transported to Tokai-mura by the Eurasian continental air mass.

• 한국건축시공학회지
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• 제12권3호
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• pp.266-274
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• 2012

The annual expenditure on diesel oil and heavy oil in the construction sector is the second largest among all industrial sectors. To meet the government's greenhouse gas reduction targets, the construction sector has until 2020 to cut its emissions by 7.1%. Unlike other high-tech industrial sectors, the construction sector has a fairly limited scope for technological improvements, which hampers its capacity to achieve the reduction target. To reduce emissions, it is necessary to establish an energy and emissions strategy at the project planning stage, and energy use and the resulting emissions must be estimated. This research aims to establish an estimation methodology for greenhouse gas emissions at the planning stage of construction projects. To estimate the project-related emissions, this research indentified the relationship among the types of emissions in a cross-sectional matrix form, and then provided a set of calculation methods for total project related emissions.

• Structural Engineering and Mechanics
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• 제54권2호
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• pp.363-378
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• 2015

Estimation of geotechnical properties is an essential but challenging task since they are major components governing the safety and reliability of the entire structural system. However, due to time and budget constraints, reliable geotechnical properties estimation using traditional site characterization approach is difficult. In view of this, an alternative efficient and cost effective approach to address the overall uncertainty is necessary to facilitate an economical, safe and reliable geotechnical design. In this paper a probabilistic approach is proposed for real-time updating by incorporating new geotechnical information from the underlying project site. The updated model obtained from the proposed method is advantageous because it incorporates information from both existing database and the site of concern. An application using real data from a site in Hong Kong will be presented to demonstrate the proposed method.

• 소음진동
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• 제2권3호
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• pp.193-202
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• 1992

The unbalance response analysis is one of the essential area in the forced vibration analysis of rotor bearing systems because of it usefulness in balancing and diagnosis as well as identification of parameters involved in rotor bearing systems. However some unbalance responses are not measurable due to the fact that rotor bearing systems are often encapsulated by fixtures or safety protectors. In the present paper, an efficent estimation scheme for unmeasured unbalance responses in rotor bearing systems is developed. The fundamental fearture of the proposed method is characterized by the linear formulae to estimate the unbalance responses from the measured unbalance responses and the finite element auxilliary model equation which is constructed to be identical to the prototype excluding the uncertain parameters such as bearing coefficients. The identification formulae for bearing parameters are also derived by using the unbalance response and the finite elements auxiliary model. Simulation is provided to verify the effectiveness of the proposed method.

• 한국가스학회지
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• 제13권3호
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• pp.43-48
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• 2009

The energetic and environmental problems have been getting serious after the revolution of modern industry. Therefore, demand of gas as an eco-friendly energy source is increasing. With the demand of gas, the use of gas is also increased, so injury and loss of life by the fire have been increasing every year. Hence the influence on flame caused by Vapor Cloud Explosion in enclosure of experimental booth was calculated by using the API regulations. And the accident damage was estimated by applying the influence on the adjacent structures and people into the PROBIT model. According to the probit analysis, the spot which is 5meter away from the flame has nearly 100% of the damage probability by the first-degree burn, 27.8% of the damage probability by the second-degree burn and 14.5% of the death probability by the fire.