• Mass Spectrometry Letters
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• 제7권4호
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• pp.102-105
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• 2016

This study explored the feasibility of using a carburization technique to enhance the ion intensity of isotopic analysis of ultra-trace levels of uranium using thermal ionization mass spectrometry (TIMS). Prior to fixing uranium samples on TIMS filaments, graphite powder suspended in nitric acid was deposited on rhenium filaments. We observed an enhancement of $^{238}U^+$ intensity by a factor of two when carburization was used, and were able to roughly optimize the amount of graphite powder necessary for carburization. The positive shift in heating current when evaporating filaments upon carburization implies that uranium was chemically altered by carburization, when compared to normal fixation processes. The good agreement between our method and known standards down to an ultra-trace level shows that the proposed technique can be applied to isotopic uranium analysis down to abundances of ~10 pg.

• 소성∙가공
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• 제4권3호
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• pp.267-281
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• 1995

Preform design is one of the critical fields in metal forming. The finite element method(FEM) has been effective in designing preforms and process sequence, for which the backward tracing scheme of the rigid-plastic FEM has been explored. In this work a program using the backward tracing scheme by the rigid-plastic FEM is developed for three-dimensional plastic deformation, which is an extension of the scheme from two-dimensional cases. The calculation of friction between workpiece and die, and handling of boundary conditions during backward tracing require sophisticated treatment. The developed program is applied to upsetting of a rectangular block and to side pressing of a cylindrical workpiece. The results of the two applications show feasibility of the program on three-dimensional plastic deformation.

• 한국식생활문화학회지
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• 제29권6호
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• pp.549-556
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• 2014

This study aimed to determine consumer satisfaction according to selection attributes of specialized coffee shops and also understand the effects of consumer satisfaction on recommendation intention and revisit intention. Through positive analysis, the study produced the following results. In the factor analysis of selection attributes of specialized coffee shops, there were six factors: 'quality', 'brand image', 'economic feasibility', 'menu diversity', 'the atmosphere and convenience of the shop', and 'service'. Among these factors, 'brand image', 'economic feasibility', and 'menu diversity' were found to exert a significant influence on consumer satisfaction. Second, consumer satisfaction had a significant influence on recommendation intention and revisit intention. Third, consumer intention to revisit specialized coffee shops showed a significant influence on recommendation intention.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1447-1457
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• 2008

The operation of the Seat-type Express Electric railway (SEE) has been watched for an alternative plan according to the increase of competition among the vehicle in metropolitan city. The purpose of this study was to examine a feasibility for the adoption of the SEE by analysis of various condition in the double tracked Souel-Chuncheon line. Fare estimate, station selection for SEE, managerial plan, demanding forecasting and analysis were performed to compute financial efficiency. The results showed financial validity on Revenue Cost Ratio (R/C), Financial Net Present Value (FNPV), Financial Internal Rate of Return (FIRR). This results indicate the evidence that SEE is a new means which is able to complement for finance, transportation capacity in metropolitan city.

• Ocean and Polar Research
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• 제32권3호
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• pp.255-265
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• 2010

This study evaluated economic feasibility and provided rationale for the development of the Korean Operational Oceanographic System (KOOS). KOOS is supposed to be established for the preservation and management of marine environments, and for the safety of ocean activities. Economic issues associated with operational oceanographic systems are discussed. During the operational period of KOOS associated with conservative small-input scenarios, and according to the macroeconomic inputoutput analysis, the system was estimated to generate 8.3 times its actual proposed economic investment (about KRW 327.7 billion). Other rationales that cannot be easily quantified were also discussed.

• 경영과학
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• 제30권2호
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• pp.1-10
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• 2013

Case studies are made to investigate the relationship between the accuracy of energy production estimation and project feasibility indicators such as rate of return on equity (ROE) and debt service coverage ratio (DSCR) for three wind farm projects. It is found out that 1% improvement in the accuracy of energy production estimation may enhance the ROE by more than 0.5% in the case of P95, thanks to improved financing terms. AHP survey shows that MCP correlation of measured in situ wind data with long term wind speed distribution and hands-on experiences of flow analysis are more important than other factors for more precise annual energy production estimation.

• 한국기술혁신학회:학술대회논문집
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• 한국기술혁신학회 2017년도 추계학술대회 논문집
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• pp.535-546
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• 2017

국가 R&D 사업에 대한 예비타당성조사 시 R&D 중복성에 대한 검토는 중복된 투자를 방지하여 재정 투자의 효율성을 높이는데 중요하다. 본 연구에서는 예비타당성조사 담당자들을 대상으로 중복성 검토에 대한 중요요인, 개선사항, 판단기준, 판단주체에 대한 설문조사 분석을 진행하였고, 외부 전문가 그룹의 인식차이와 비교하였다. 설문조사 결과에 대한 통계 분석을 통해 중복성 검토에서 가장 중요한 요인은 '중복성 판단기준, 시스템의 데이터베이스 및 검색 알고리즘'으로 확인되었고, 3가지 요인에 대한 개선이 중복성 검토를 개선하는데 가장 중요함을 확인하였다. 또한 다중회귀분석을 통해 주요 요인들이 중복성 검토결과의 정확성에 미치는 영향성을 분석하여 요인들의 유의성에 대해 확인하였다. 본 연구를 통해 예비타당성 조사 시 R&D 중복성에 대한 검토가 향후 어떤 방향으로 개선되어야하는지에 대해 시사점이 제시된다.

• 한국정밀공학회지
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• 제16권3호통권96호
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• pp.18-24
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• 1999

ThisPaper investigates the feasibility of using acoustic emission signal analysis for the detection of built-up edge during machining. Experiments were conducted on a CNC-lathe using conventional carbide insert tools under various cutting conditions. The cutting forces were also measured for comparisons. Experimental evidence is presented which indicates that the presence of a built-up edge can significantly affect the generation of acoustic emission in metal cutting. It is shown that under conditions in which a built-up edge is generated, the variation of $AE_{rms}$ signal with cutting speed can be quite different from the generally accepted linear, monotonic increase as previously reported. The feasibility of utilizing $AE_{rms}$ in built-up edge sensing is suggested.

• 한국압력기기공학회 논문집
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• 제14권2호
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• pp.88-95
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• 2018

In this study, to enhance the seismic performance of nuclear power plants (NPP), a small laminated rubber bearing (LRB) is chosen as a seismic design option of the vulnerable equipment. Prior to the application of equipment base isolation, it is necessary to review the feasibility that the technique contributes enough to the seismic performance of NPP by analysis. At first, some preliminary design of small LRBs for equipment is carried out. Design parameters such as horizontal and vertical stiffnesses, design natural frequencies are checked by calculation and analysis for the four design options considering various upper weights. Performance test of small LRB is to be carried out to verify static performance using the results.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.276-279
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• 2015

Along with the increase of the quantity of data in various industries, the construction industry has also developed various systems focusing on collecting data related to the construction performance such as productivity and costs achieved in construction job sites. Numerous researchers worldwide have been focusing on developing efficient methodologies to analyze such data. However, applications of such methodologies have shown serious limitations on practical applications due to lack of data and difficulty in finding appropriate analytic methodologies which were capable of implementing significant insights. With development of information technology, the new trend in analytic methodologies has been introduced and steeply developed with the new name of "big data analysis" in various fields in academia and industry. The new concept of big data can be applied for significant analysis on various formats of construction data such as structured, semi-structured, or non-structured formats. This study investigates preliminary application methods based on data collected from actual construction site. This preliminary investigation in this study expects to assess fundamental feasibility of big data analytic applications in construction.