• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.451-456
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• 1997

각 사업소의 교정용 팬톰에 대한 유효성 여부를 판정하고, 측정결과의 정확도와 조직적 오차의 발생여부를 확인할 목적으로 현재 국내 원전에서 사용중인 In Vivo 시스템에 대한 성능 시험을 수행하였다. 성능시험의 내용과 절차는 미국의 관련 지침인 ANSI N13.30에 기초를 두었다. 전신 측정에 대한 성능시험 결과, 시험핵종의 편중, 정밀도 및 최소검출방사능은 ANSI N13.30에서 정한 용인한도 이내로 나타났으며, 또 폐, 하복부 및 갑상선 측정에 대한 성능시험결과에 있어서도 성능평가 항목의 값은 모두 용인한도 이내였다. 각 사업소의 교정용 팬톰과 성능시험용 팬톰이 기하학적 구조에서 다소 차이가 있다 할지라도 측정결과의 편중이 용인한도 이하였다는 사실로부터 각 사업소에서 보유하고 있는 교정용 팬톰의 유효성을 간접적으로 입증할 수 있었다.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2007.05a
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• pp.55-56
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• 2007

• Proceedings of the Korean Nuclear Society Conference
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• 2003.05a
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• pp.303.2-303.2
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• 2003

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2019.05a
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• pp.343-344
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• 2019

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2016.05a
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• pp.249-250
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• 2016

• The Journal of Advanced Prosthodontics
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• v.8 no.3
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• pp.201-206
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• 2016

PURPOSE. The aim of this study was to compare the radiopacity of 6 modern resin cements with that of human enamel and dentine using the Digora digital radiography system, to verify whether they meet the requirements of ANSI/ADA specification no. 27/1993 and the ISO 4049/2000 standard and assess whether their radiopacity is influenced by the thickness of the cement employed. MATERIALS AND METHODS. Three 3-thickness samples (0.5, 1 and 1.5 mm) were fabricated for each material. The individual cement samples were radiographed on the CCD sensor next to the aluminium wedge and the tooth samples. Five radiographs were made of each sample and therefore five readings of radiographic density were taken for each thickness of the materials. The radiopacity was measured in pixels using Digora 2.6 software. The calibration curve obtained from the mean values of each step of the wedge made it possible to obtain the equivalent in mm of aluminium for each mm of the luting material. RESULTS. With the exception of Variolink Veneer Medium Value 0, all the cements studied were more radiopaque than enamel and dentin (P<.05) and complied with the ISO and ANSI/ADA requirements (P<.001). The radiopacity of all the cements examined depended on their thickness: the thicker the material, the greater its radiopacity. CONCLUSION. All materials except Variolink Veneer Medium Value 0 yielded radiopacity values that complied with the recommendations of the ISO and ANSI/ADA. Variolink Veneer Medium Value 0 showed less radiopacity than enamel and dentin.

• Journal of Radiation Protection and Research
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• v.21 no.4
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• pp.255-262
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• 1996

This paper describes the results of intercomparison measurements of KAERI reference photon and beta radiation fields between the KAERI and the PNNL(Pacific Northwest National Laboratory), recently performed at KAERI radiation calibration and dosimetry laboratory on the basis of the ANSI N13.11 criteria for personal dosimeter performance test. Each laboratory used her own radiation detectors or measurement devices traceable to her national primary standard in measuring the exposure rates for photon fields, the absorbed dose rates for beta radiation fields. The agreements in reference radiation measurements between two laboratories were found to be less than ${\pm}2.0%$ for photon fields, ${\pm}1.0%$ for beta radiation fields. Therefore, it could be concluded that KAERI reference radiation fields comply well with the international standard and thus can further serve as a national basis for the researches and developments in radiation protection dosimetry in Korea.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.6
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• pp.883-888
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• 2010

This study have goal with conceptual design for Offshore Structures of high pressure control valve for localization. Ball valve for development accomplished with flow analysis based on provision of ANSI B16.34, ANSI B16.10, ANSI B16.25 In order to localize the Offshore Structures high pressure control valve. Numerical simulation using CFD (Computational Fluid Dynamic) in order to predict a mass flow rate and a flow coefficient form flow dynamic point of view. The working fluid assumed the glycerin (C3H8O3). The valve inlet and outlet setup a pressure boundary condition. The outlet pressure was fixed by atmospheric pressure and calculated until increasing 1bar to 10bar. CFD analysis used STAR-CCM+ which is commercial code and Governing equations were calculated by moving mesh which is rotated 90 degrees when ball valve operated opening and closing in 1 degree interval. The result shows change of mass flow rate according to opening and closing angle of valve, Flow decrease observed open valve that equal percentage flow paten which is general inclination of ball valve. Relation with flow and flow coefficient can not be proportional according to inlet pressure when compare with mass flow rate. Because flow coefficient have influence in flow and pressure difference. Namely, flow can be change even if it has same Cv value. The structural analysis used ANSYS which is a commercial code. Stress analysis result of internal pressure in valve showed lower than yield strength. This is expect to need more detail design and verification for stem and seat structure.

• The KSFM Journal of Fluid Machinery
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• v.17 no.2
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• pp.24-29
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• 2014

In general, a large-capacity axial flow fan is used for industrial processes or ventilation in a social overhead capital infrastructure. The main characteristics of the large axial-flow fan need a lot of electrical power consumption and operate 24 hours a day, 365 days a year. Since the large axial flow fan consumes several hundreds to thousands kW per hour, both manufacturer and consumer are struggling to select high efficiency products for saving energy and reducing operation cost. Therefore, the performance testing should be accurately conducted in experimental equipments. The performance estimation and uncertainty of measurement of the axial-flow fan gathered from the result from nozzle shaped testing equipments certified with ANSI/AMCA standard and duct shaped testing equipment under the same experimental condition. The experimental results from both facilities have maximum 17% differences in performance evaluation and uncertainty of measurement. As considering that the differences, it is doubt about the reliability of testing result. The test was repeated with the specific term during 12 months because it is important to fully reflect the real conditions and to decide the repeatability of data. The evaluation of duct type testing facilities was failed to get an uncertainty measure. Testing results were previously published. As a series of previous paper, axial fan (∅1690 mm) and duct type testing facilities were fabricated. The purpose of fabricating testing equipment was testing an uncertainty measurement under the controlled environments.

• Journal of Radiation Protection and Research
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• v.22 no.4
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• pp.263-272
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• 1997

A Radiation Alarm Monitor has been developed and manufactured in order to protect radiation workers from over-exposure. A visual and audible alarm system has been attached to initiate evacuation when accident occurs such as an unexpected change of radiation level or an over-exposure. The Radiation Alarm Monitor installed with microprocessor can record the information of radiation field change between 90 min. before the alarm and 30 min. after the alarm and also provide the data to an IBM compatible computer to analyze the accidents and to set a counterplan. It features a wide detection range of radiation field(10 mR/h-100 R/h), radiation field data storage, portability, high precision (${\pm}5%$) due to self-calibration function, and adaption of a powerful alarm system. According to ANSI N42.17A, the most stringent test standards, performance tests were carried out under various conditions of temperature, humidity, vibration, and electromagnetic wave hindrance at Korea Research Institute of Standards & Science (KRISS). As a result, the Radiation Alarm Monitor passed all tests.