• Journal of Mechanical Science and Technology
• /
• 제14권11호
• /
• pp.1216-1224
• /
• 2000

The collapse pressure of tubes is determined experimentally by Tschoepe and Maison for various materials with different geometries. The results are compared with those obtained by ASME Codes UG-31 and UG-28. A collage pressure is the pressure required for the incipient yielding stress of the tubes with and without ovality. This collapse pressure is compared with the experimental results by Tschoepe and Maison. The present investigation is towards finding the collapse pressure required to bring the entire wall of tubes into a state of plastic flow for the pipes, with ovality and without ovality. This collapse pressure is compared with the collapse pressure obtained through experiments in the present investigation. The experimental results are compared with the pressure obtained by FEM(finite element methods). The FEM results are then compared with results obtained through an approximate plastic analysis of the strain hardening material, SA312-TP304 stainless steel. The structural integrity evaluation is performed for the heat exchanger used in an actual nuclear power plant by using various methods described in this paper. The results obtained by the various analyses and the FEM are discussed. consequently, the paper is oriented towards an actual design purpose of d heat exchanger in an industrial environment, rather than for the purpose of an academic research project investigation.

• 방사성폐기물학회지
• /
• 제17권4호
• /
• pp.389-403
• /
• 2019

Large amounts of concrete waste are likely to arise from the decommissioning of a Kori-1 nuclear power plant. Several studies have been conducted on decommissioning concrete waste in recent decades, however, they have been limited to contaminated concrete issues or were small pilot-scale experiments. This study constructed two industrial-scale models of on-site concrete waste management for clean as well as contaminated concrete. To evaluate the performance of both the models, simulations were conducted using the Flexsim software. The concrete particle size distribution of Kori-1 and concrete processor properties based on widely used construction equipment were used as sources of input data for the simulations. It was observed that it may take over two years to complete the on-site concrete management processes owing to the performance of existing processors. In addition, it was demonstrated that it is essential to identify bottlenecks in the system and enhance the performance of the relevant processors to avoid delays of the decommissioning schedule. Our results suggest that this novel approach can contribute to developing schedules or expediting delayed activities in the Kori-1 decommissioning project.

• 대한인간공학회지
• /
• 제31권1호
• /
• pp.211-217
• /
• 2012

Objective: The aim of this study is to show a correct application procedure using the compact Korean anthropometric data application program called Korean Human Scale(KHS) for anthropometric design. Background: The nation-wide anthropometric survey project called 'Size Korea' developed KHS and distributed it to the public on the web site. But some insufficiency of the current web service of KHS misleads the users; they just put their own statue and pick up a meaningless data for a body dimension. Method: This study provides five steps to follow to read appropriate data from KHS for an anthropometric design. Results: As a case study, the depth dimension of the supervisory and control console used in the Korea nuclear power plant was determined following the procedure and compared with the console design guideline recommendation. Conclusion: The supplementary anthropometry table should be added on the web service of KHS for users to read a meaningful data for design. Application: If properly used, the KHS has a lot more potential application area than users can expect such as in control center design area.

• 품질경영학회지
• /
• 제33권1호
• /
• pp.32-41
• /
• 2005

This paper presents a six sigma application case study for an automobile steering wheel manufacturing process using rolled throughput yield improvement activity. Hidden factory and first pass yield concept is introduced and a DMAIC procedure is implemented to maximize the first pass yield. The result of the six sigma project amounts to the reduction of failure cost of 1.2 billion won per year in the steering wheel manufacturing process. This paper can benefit six sigma practitioners in some ways.

• 산업공학
• /
• 제13권4호
• /
• pp.751-758
• /
• 2000

Situation awareness is defined as a person's perception of the elements of the environment within a volume of time and space, the comprehension of their meaning and the projection of their status in the near future. Situation awareness is important in attempting to evaluate human behavior in operating complex systems such as aircraft, air traffic control, and nuclear power plant systems. From the literatures this study reviews the relationship between situation awareness and numerous individual, system and environmental factors, and also reviews the methodologies for the empirical measurement of situation awareness applicable to Korea Next Generation Reactor (KNGR) design project. Attention, working memory, workload, stress, system complexity, and automation are presented as critical factors limiting operator's situation awareness. Mental models and goal-directed behavior are hypothesized as important mechanisms overcoming these limits. This study summarized hypothesized guidelines for interface design to improve situation awareness of reactor operators. Some of the guidelines should be tested in the KNGR evaluation experiments in the future.

• 무역상무연구
• /
• 제48권
• /
• pp.127-155
• /
• 2010

The international transactions of capital goods such as industrial plant exports, overseas constructions, and shipbuilding exports, are so huge that tremendous amount of funds are required, and that most of the loans are long-term credits of over five years. In the export of huge capital goods, financing is more crucial than technology itself. Some of the importing countries are developing ones that are politically and economically unstable. Therefore the financing mechanism for these transactions is conclusive in winning these projects. Global financial market instability caused by US sub-prime mortgage financial crisis expanded all over the world, and the international transactions have been decreased due to global credit crisis. This indicates how much influential the financing market is in international transactions. The financing schemes are classified into supplier credit and buyer credit by who provides the financing. A supplier credit is a credit extended by an exporter(seller) to an importer(buyer) as part of an export contract. Cover for this transaction may be extended by an export credit agency('ECA') to the exporter. In a sales contract a seller shall provide fund required to manufacture goods, and in a construction contract a contractor shall provide fund required to complete a construction. A buyer credit is an arrangement in which an exporter enters into a contract with an importer, which is financed by means of a loan agreement A Comparative Study on a Supplier Credit and a Buyer Credit in International Transactions of Capital Goods 155 where the borrower is the importer. In a sales contract a buyer shall provide fund required to manufacture and procure the goods, and in a construction contract an owner shall provide fund required to complete a construction. Therefore an exporter is paid on progressive payment method. A supplier credit and a buyer credit have their own advantages and disadvantages in the respect of the parties respectively. These two financing methods are selectively used considering financing conditions such as funding cost, importer's and/or exporter's financial conditions, importing country's political risk.

• 한국산학기술학회논문지
• /
• 제18권10호
• /
• pp.48-53
• /
• 2017

농림축산식품부의 주요정책 중 하나가 농식품 수출액 100억 달러 달성이다. 2016년 현재 농식품 수출액은 65억달러로 수출목표 달성이 그리 쉽지는 않은 상황이다. 농림축산식품부 사업인 시설현대화사업, 첨단온실사업 등은 원예작물의 수출을 전제로 시행되고 있다. 이러한 정책 기조에서 수출활성화와 동시에 수입과일의 국내 직접재배를 통한 수입대체 효과를 고려할 필요가 있다. 온대 및 열대 신선과일 수입액은 2000년에 2천 억에서 2016년 1조 2천 억으로 6배 증가하였다. 온대 및 열대 신선과일 수입을 대체할 수 있는 방안을 찾아 시행한다면 농가소득을 올리고 과수농가의 성장도 이끌 수 있다. 우리나라에서 온 열대 과일 생산의 핵심과제는 난방비를 절감하는 것이다. 제주도 애플망고 생산 농가가 면세 등유와 발전소 온배수를 이용한 경우를 조사하여 비교 분석하였다. 분석결과에 의하면 난방비가 42.3% 감소하였다. 난방비 문제 해결 대안 중 발전소 온배수를 활용한 방안을 고려할 수 있다. 온배수를 이용하면 난방비를 획기적으로 줄일 수 있을 뿐만 아니라, 수입 과일을 국내 생산으로 대체하는 효과를 얻을 수 있다. 수입과일과의 가격경쟁을 위해서 현재 시행되고 있는 여러 정부지원사업(국비 보조20%, 융자 20%, 지방비 30%, 자부담 20%)을 수입과일 대체를 위한 생산농가에게 적용하게 되면 상당한 효과가 있을 것으로 판단된다. 이 연구는 발전소 온배수를 활용하여 수입되고 있는 온대 및 열대 과일의 국내 생산을 위한 정책구상에 대한 검토와 더불어 몇 가지 정책적 시사점을 제안하고 있다.

• 해사법연구
• /
• 제29권2호
• /
• pp.115-144
• /
• 2017

2007년 미국에서 시작된 글로벌 금융위기의 영향은 국내의 해운 조선 분야에도 크게 영향을 미쳤다. 이와 관련하여 국내 조선소는 해운경기 악화로 인한 상선 수주물량 감소의 대체수단으로 여러 방면에서 수주전략을 수립하였고, 선택한 분야가 해양플랜트였다. 그러나 국내 조선소는 해양플랜트 관련 계약이 갖고 있는 위험성 분석에 대한 대비 없이 단순한 매출액 확대와 일감확보를 위한 무리한 영업 수주전략을 추진하였다. 이러한 결과, 해양플랜트 발주자와 초기에 계약한 금액보다 많은 비용이 투입되거나 제조물 인도지연에 따른 지체상금을 지급해야 하는 법적인 문제로 확대되었다. 주요 법적분쟁의 원인은 해양플랜트공사 시 발생할 수 있는 비선형모델에 의한 위험성 분석, 공정관리의 미숙, 국내 조선소가 "Engineering Procurement Construction 일괄계약"을 사용하는 해양플랜트공사계약의 이해 부족에 기인한다. 특히, 위험성 관리 항목의 한 요소로써 계약상의 독소조항에 대한 충분한 검토가 이루어지지 않은 점에 있다. 이러한 계약서를 검토할 만한 인력도 부재하다. 따라서 이 연구에서는 계약목적물의 인도지연이 발생할 수 있는 구체적 위험성의 존재를 식별하고, 해양플랜트공사계약 상에는 어떠한 불공정조항이 존재하며, 그러한 불공정조항이 실제 양 당사자에게 어떻게 적용되는지를 국내 조선소의 프로젝트 관리자의 인터뷰와 선행연구를 참조하여 구체적 위험요소가 계약상으로 어떻게 함의되는가에 대해서 살펴보았다. 이를 통하여 해양플랜트공사계약상 제조물인도지연에 관한 계약당사자의 법적 책임관계와 국내 조선 해양플랜트 산업발전에 기여할 수 있는 개선방안을 도출하였다.

• 환경영향평가
• /
• 제9권4호
• /
• pp.277-290
• /
• 2000

The purpose of this study is to identify the problems of environmental impact assessment(EIA) and to suggest new EIA technology. The problems of EIA in Korea can be summarized as follows. First, the EIA does not reflect the impact of policy, plan and program on environment. Second, the project EIA does not consider the cumulative impacts such as additive impacts, synergistic impacts, threshold/saturation impacts, induced and indirect impacts, time-crowded impacts, and space-crowded impacts. Third, the EIA techniques in Korea are not standardized. Finally, the present EIA suggests only alternatives to reduce adverse impacts. To solve above-mentioned problems, the development of new EIA technology is essential. First, the new EIA technology should be developed toward pollution prevention technology and comprehensive and integrated environmental management technology. Second, new fields of EIA for pollution prevention contain strategic environmental assessment, cumulative impacts assessment, socio-economic impact assessment, cyber EIA and EIA technology necessary after the reunification of Korean Peninsula. Third, EIA technology for integrated environmental management contains the development of integated environment assessment system and the development of packaged EIA technology. The EIA technology for integrated environmental assessment system contains (1) development of integrated impact assessment technology combining air/water quality model, GIS and remote sensing, (2) integrated impact assessment of EIA, traffic impact assessment, population impact assessment and disaster impact assessment. (3) development of integrated technology combining risk assessment and EIA (4) development of integrated technology of life cycle assessment and EIA, (5) development of integrated technology of spatial planning and EIA, (6) EIA technology for biodiversity towards sustainable development, (7) mathematical model and GIS based location decision techniques, and (8) environmental monitoring and audit. Furthermore, there are some fields which need packaged EIA technology. In case of dam development, urban or industrial complex development, tourist development, landfill or combustion facilities construction, electric power plant development, development of port, road/rail/air port, is necessary the standardized and packaged EIA technology which considers the common characteristics of the same kind of development project.

• Ocean and Polar Research
• /
• 제38권3호
• /
• pp.225-234
• /
• 2016

This project sought to conduct an economic feasibility study regarding the commercial production of bio-hydrogen by the marine hyperthermophilic archaeon, Thermococcus onnurineus NA1 using carbon monoxide-containing industrial off-gas. We carried out the economic evaluation of the bio-hydrogen production process using the raw material of steel mill by-product gas. The process parameter was as follows: $H_2$ production rate was 5.6 L/L/h; the conversion of carbon monoxide was 60.7%. This project established an evaluation criterion for about 10,000 tonne/year. Inflation factors were considered as 3%. The operating costs were recalculated based on prices in 2014. The total investment required for development was covered 30% by capital and 70% by a loan. The operation cost for the 0.5-year test and integration, and the cost for the first three months in the 50% production period were considered as the working capital in the cost estimation. The costs required for the rental of office space, facilities, and other related costs from the construction through to full-scale production periods were considered as continuing expenses. Materials, energy, waste disposal and other charges were considered as the operating cost of the development system. Depreciation, tax, maintenance and repair, insurance, labor, interest rate charges, general and administrative costs, lubrication and miscellaneous expenses were also calculated. The hydrogen price was set at US$ 4.15/kg for the economic evaluation. As a result, the process was considered to be economical with the payback period of 6.3 years, NPV of 18 billion Won and IRR of 26.7%.