• Journal of radiological science and technology
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• v.3 no.1
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• pp.21-27
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• 1980

It is the experimental report by using 17cm, 19cm in thickness water-phantom to investigate optimum tube voltage in taking skull roentgenography. The obtained results are as follows: 1. An adequate kVp for P-A projection is range from 80-90. 2. An adequate kVp for lateral projection is range from 75-85.

• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.181-182
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• 2012

• 한국약용작물학회:학술대회논문집
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• 2012.05a
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• pp.115-116
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• 2012

• 한국약용작물학회:학술대회논문집
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• 2009.05a
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• pp.409-410
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• 2009

• Korean Journal of Plant Resources
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• v.19 no.4
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• pp.459-470
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• 2006

This study was carried out objectively to analyze the distributing flora for the conservation of natural environment and to construct the database in Mt. Joryeong, Chungcheongbuk-do, Korea. The period of survey was from November, 2004 to September, 2005, and the routes were A (Recreation $forest{\sim}Shinseon-bong$), B $(Shinseon-bong{\sim}Mapae-bong)$, C(Joryeong 3rd $gateway{\sim}Mapae-bong$), and D $(Yongseong-gol{\sim}Gitdae-bong)$. The vascular plants were summarized as 341 taxa; 85 families, 219 genera, 299 species, 36 varieties, and 6 forma. The rare and endangered plants designated by Korea Forest Service were 3 taxa; Paeonia japonica, Viola albida, and Rhododendron micranthum. The Korean endemic plants were 9 taxa; Cephalotaxus harringtonia, Salix caprea, Deutzia coreana, Spiraea prunifolia for. simpliciflora, $Lespedeza{\times}tomentella$, Vaccinium koreanum, Salvia chanroenica, Weigela subsessilis, and Cirsium setidens. And in the results of survey on resource plants, we confirmed 171 taxa of ornamental plants (50.1%), 222 taxa of edible plants (65.1%), 237 taxa of medicinal plants (69.5%) and 146 taxa of other useful plants (42.8%).

• Journal of Korean Society of Water and Wastewater
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• v.19 no.4
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• pp.462-472
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• 2005

This study was carried out to suggest the plans for installation of rural sewage treatment facilities through the analysis of these facilities installed in Chungchongnam-do Province. About 5% of all installation was carried out by the department of wastewater and related environment problems and the other case was carried out by the department of construction or residence. In wastewater caused by 250 and 300 persons, facilities capacity do not exceed about $50m^3/d$, caused by 2,500 and 3,000 persons, $500m^3/d$. Advanced sewage treatment process were first needed in the discharge area where affected the water environment greatly. However, in carrying out the water quality pollutant of the total amount management system in the other areas, they should be driven only over the scale of pollutant quota object facilities standard. Rural sewage must be included in the special accounts according to the regulations of local government, and sewage treatment cost should be collected to manage. Installation type uses integrating joint treatment method in case the distance among villages is short or one treatment facility independently.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2342-2347
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• 2011

This paper introduces the performance test of the prototype vehicle, which will be in operation for Urban Maglev Program. While common trains with steel wheels use rotary induction motors for propulsion, maglev trains gain thrust force from linear induction motors maintaining the constant airgap with levitation electromagnets. Therefore, not only the behavior of the linear induction motor should be well understood, but also the way of propulsion that minimizes its effect on the levitation system should be took into account. Performance test procedures of maglev trains are proposed and carried out, and the characteristics of acceleration and deceleration are verified to agree with the design criteria. Tests are mainly performed on the linear section of the test line, and the driving characteristics on the section with a 6‰ incline are examined additionally. As a result, the performance of the prototype vehicle in the reverse operation can satisfy the requirement about the acceleration and deceleration, 4.0$m/s^2$. And, the design modifications of the commercial vehicle and the performance specifications required on the demonstration line are investigated.

• Transactions of Materials Processing
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• v.7 no.3
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• pp.233-245
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• 1998

A new approach has been proposed for the incremental analysis of the nonsteady state large deformation of planar anisotropic elastic-plastic sheet forming. A mathematical brief review of a constitutive law for the incremental deformation theory has been presented from flow theory using the minimum plastic work path for elastic-plastic material. Since the material embedded coordinate system(Lagrangian quantity) is used in the proposed theory the stress integration procedure is completely objective. A new return mapping algorithm has been also developed from the general midpoint rule so as to achieve numerically large strain increment by successive control of yield function residuals. Some numerical tests for the return mapping algorithm were performed using Barlat's six component anisotropic stress potential. Performance of the proposed algorithm was shown to be good and stable for a large strain increment, For planar anisotropic sheet forming updating algorithm of planar anisotropic axes has been newly proposed. In order to show the effectiveness and validity of the present formulation earing simulation for a cylindrical cup drawing and front fender stamping analysis are performed. From the results it has been shown that the present formulation can provide a good basis for analysis for analysis of elastic-plastic sheet metal forming processes.

• Proceedings of the KIEE Conference
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• 2007.11b
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• pp.9-11
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• 2007

우리나라는 정부의 전력시장 구조개편 계획에 의거 2001년부터 전력시장을 도입하도록 하는 결정에 따라 초기단계 전력시장을 운영하기 위한 "발전경쟁 (CBP Cost Based Pool)시스템"을 국내기술로 개발하여 현재까지 운영중에 있다. 또한 단계적인 시장도입 정책에 따라 2004년 4일부터 운영할 예정이었던 전력시장운영시스템(MOS : Market Operating System)은 정부의 도매전력시장 개설중단이란 정책변경으로 우수한 성능과 기능을 보유하고 있음에도 불구하고 활용이 불투명하기 도 하였으나, 2007년 세계최초로 발전경쟁시장시스템에 접목하여 MOS 상업운전을 개시하여 경제급전 효과를 극대화 할 수 있게 되었다. 경제급전 및 계통안정운영을 위한 MOS 시스템의 기능중 하나인 급전지시시스템(MX : Massage Exchange)은 미국 ABB사에서 개발하였던 초기의 기능은 매우 초보적인 단계로 단순히 5분 에너지 급전지시값만 전달하는 것으로서 국내 급전운영체계의 반영이 미흡하였다. 이에 따라, 2005년 국내기술로 초기 시스템을 개발한 이후 2007년에는 에너지 급전지시값 외에 보조서비스 데이터 제공 등의 성능 개선을 통해 중앙급전소 급전원, 현장 발전운전원 등에게 정확하고 신속한 계통운영관련 DATA를 실시간으로 제공하여, 계통운전에 활용함으로서 전력계통의 안정운영과 효율적인 시장운영에 많은 도움을 주고 있다. 본 논문에서는 이와 같이 완벽한 계통운전의 실현과 효율적 시장운영에 중요한 요소로서 역할을 수행하고 있는 급전지시 시스템의 개요와 주요 내용에 대해 살펴보도록 하겠다.

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.597-598
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• 2006

자기누설탐상법은 비파괴검사 방법의 하나로 대상물체를 외부에서 착자시켜 결함이 발생할 경우에 결함부위에서 자기누설이 발생하도록 하여, 누설된 자기장을 측정하여 결함의 유무와 크기 등을 판정하는 시스템이다. 본 논문에서는 MFL 방식의 범용 NDT 검사기의 개발을 위해 영구자석을 이용하여 소형 비파괴 검사기를 설계하고, 3차원 유한요소법을 이용하여 해석하고 실제 데이터를 측정하여 그 결과를 비교 분석하였다.