• Journal of Advanced Research in Ocean Engineering
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• 제3권4호
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• pp.184-192
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• 2017

The Korea Offshore Wind Power (KWOP) cooperation is planning to construct offshore wind energy farms with an overall rated power of 2.5 GW along the southwestern coast by 2019. Hitherto, various structural types of support structures for offshore wind turbines have been being proposed, but these structures have lacked economic analysis studies. Therefore, their economical superiority to existing types has been difficult to guarantee. An offshore structure with economic efficiency will have a minimum amount of mobilizing equipment and short offshore construction period because of the application of rapid installation methods. Thus, the development of a new support structure with economic efficiency is generally considered to be necessary. Accordingly, this paper proposes a newly developed and more economical jacket type for the offshore support structure. This study confirmed its structural safety and performance by conducting a structural analysis and eigenvalue analysis. The manufacturing and installation costs were then estimated. As a result, the new jacket type of offshore support structure proposed in this study significantly reduced the manufacturing and installation costs. Therefore, it is expected that the proposed jacket will contribute to reducing construction expenses for new wind power farms and invigorating wind power farm businesses.

• Computers and Concrete
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• 제17권5호
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• pp.579-596
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• 2016

This paper describes a method of the refined plastic hinge approach in the framework of the higher-order element formulation that can efficaciously evaluate the limit state capacity of a whole reinforced concrete structural system using least number of element(s), whereas the traditional design of a reinforced concrete structure (i.e. AS3600; Eurocode 2) is member-based approach. Hence, in regard to the material nonlinearities, the efficient and economical cross-section analysis is provided to evaluate the element section capacity of non-uniform and arbitrary concrete section subjected to the interaction effects, which is helpful to formulate the refined plastic hinge method. In regard to the geometric nonlinearities, this paper relies on the higher-order element formulation with element load effect. Eventually, the load redistribution can be considered and make full use of the strength reserved owing to the redundancy of an indeterminate structure. And it is particularly true for the performance-based design of a structure under the extreme loads, while the uncertainty of the extreme load is great that the true behaviour of a whole structural system is important for the economical design approach, which is great superiority over the conservative optimal strength of an individual and isolated member based on traditional design (i.e. AS3600; Eurocode 2).

• Structural Engineering and Mechanics
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• 제47권2호
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• pp.265-286
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• 2013

A study on economic performances of consecutive multi-span suspension bridges is carried out. In this part of the study, material amount and structural cost estimation formulas of the bridges is derived based on the structural ultimate carrying capacity. The bridge cost includes the part of superstructure and the part of substructure. Three types of bridge foundations, bored piles, concrete caissons and floating foundations, are considered in substructure. These formulas are to be used for the parametric study of the bridge cost in order to define its more economical layout under different conditions in the part two of the study.

• Steel and Composite Structures
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• 제24권3호
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• pp.277-285
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• 2017

Single-storey industrial buildings are one of the most often type of structures built among various skeletal framed steel constructions. These metallic buildings offer an exceptional opportunity to minimise the material employed, contributing to a more sustainable construction. In particular, the mansard portal frame is a typology made up of broken beams that involves different lengths and discontinuous slopes. This study aims the weight reduction of the standard mansard portal frame with design purposes by means of varying four parameters: the kink position, the eaves-apex slope, the span and the columns height. In this work, we suggest some guidelines that can improve the economical competitive capabilities of their structural design. In all the cases analysed, the joints of the portal frame are placed over the theoretical non-funicular shape to uniform loads. This allows reducing the bending moment and the shear force, but increasing the axial force. In addition, the performance of mansard and typical pitched portal frames submitted to the same boundary conditions is compared in terms of efficiency in the use of steel. In the large majority of the cases, mansard typologies are lighter than the common pitched frames and, hence, more economical.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.311-316
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• 2004

전문건설업계는 공사대금의 미 회수 등 외부요인에 의한 경영악화가 심화되고 있으며, 장기어음수급에 따른 어음 할인료부담 가중으로 공사의 채산성이 악화되고 있다. 이에 따라서 정부는 현금성결제수단을 도입하였으나 현재 이행실태가 일부 기업을 제외하고 미미한 실정이다. 따라서 본 연구는 현금성결제수단 중 기업구매자금 대출수단에 대해 타당성을 분석하고 손익기준점을 통한 경제적인 대금지급수단의 기준안을 제시하고 기초적인 데이터를 제공하는데 목적이 있다.

• Journal of Microbiology and Biotechnology
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• 제28권8호
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• pp.1346-1351
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• 2018

Oxidoreductases are effective biocatalysts, but their practical use is limited by the need for large quantities of NAD(P)H. In this study, a whole-cell biocatalyst for NAD(P)H cofactor regeneration was developed using the economical substrate glycerol. This cofactor regeneration system employs permeabilized Escherichia coli cells in which the glpD and gldA genes were deleted and the gpsA gene, which encodes $NAD(P)^+-dependent$ glycerol-3-phosphate dehydrogenase, was overexpressed. These manipulations were applied to block a side reaction (i.e., the conversion of glycerol to dihydroxyacetone) and to switch the glpD-encoding enzyme reaction to a gpsA-encoding enzyme reaction that generates both NADH and NADPH. We demonstrated the performance of the cofactor regeneration system using a lactate dehydrogenase reaction as a coupling reaction model. The developed biocatalyst involves an economical substrate, bifunctional regeneration of NAD(P)H, and simple reaction conditions as well as a stable environment for enzymes, and is thus applicable to a variety of oxidoreductase reactions requiring NAD(P)H regeneration.

• 대한안전경영과학회지
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• 제13권2호
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• pp.203-210
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• 2011

Incheon Port has been served as not only the center of the Yellow Sea and port for trade with China but also domestic gateway port for the metropolitan area, playing a professional role as the greatest domestic Port which processes a variety of items such as imported raw materials, bulk cargo, oil and gas and so on. This study was conducted based on step by step business process between port entry and departure of ship, and incurred cost according to port industry classification and performance on the port facility. Bulk cargo and general cargo such as grain, food, steel, scrap metal, wood, coal, LNG, LPG and oil etc., which have a vast majority of import goods, have been treated by 57,062 thousand tons and 7,409 thousand tons of container cargo were processed at Incheon Port in 2009. Bulk vessels and carriers moving items such as LPG, LNG and oil recorded 38,836 thousand won and full-container vessels recorded 11,001 thousand won as the amount of notified port facility usage fees in 2008.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.148-154
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• 2009

By the skyscraper building, increase of skin area and expansion of curtain wall system will be the important factors of acceleration in extending supply of BIPV system. In the future interior environmental evaluation is not a necessary to the residents but an essential term which will bring enormous influence. In the interior environmental evaluation, natural light will let the residents with direct contact with outside circumstances and make them feel opened. also only the daylight has radiant energy and color rendering that will have a great influence to residents' mental, operation efficiency and advancing productivity. This research compares and analyzes BIPC system in office spaces with two general sunlight's module. In addition to natural light's efficiency for BIPC system's comfort and confirmed economical efficiency will be applied to basic research data. Hence forth, ensuring indoor intensity of illumination and controlling light system to reducing energy research data will be demanded to increase the amount of supplying BIPC system. Also continuance research in the possibility of applying BIPC system in various buildings, room temperature affected by location of windows and its condensation, and economical evaluation will be required.

• 콘크리트학회논문집
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• 제19권4호
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• pp.507-514
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• 2007

이 논문은 기존 내진설계와 비교하여 면진설계의 효용성과 경제적 효과에 대한 연구 결과를 정리한 것이며, 면진설계에 있어서는 납봉삽입적층고무베어링 (LRB)만을 사용한 경우와 비교하여 슬라이딩베어링과 LRB를 혼용한 면진시스템의 내진 거동을 함께 제시하였다. 연구 결과, 면진은 구조물에 대하여 지진동으로 인한 효과를 감소시키는데 매우 효과적이며, 층 가속도의 감소로 사용성을 증가시킬 수 있음이 입증되었다. 또한 층 가속도와 밑면 전단력의 감소라는 관점에서 슬라이딩베어링과 LRB를 혼용한 면진시스템이 LRB만을 사용한 경우보다 더 효과적임을 증명하였다. 하지만 경제적 효과 면에서는 증가된 성능에 비례하여 지불해야만 하는 비용도 커진다는 사실에 특별히 주의할 필요가 있는 것으로 나타났다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2008년도 춘계 학술발표회 제20권1호
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• pp.941-944
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• 2008

PVA 섬유, 강섬유를 다량으로 혼입한 고인성 시멘트 복합체가 개발되고 이를 구조물에 활용하고자 하는 연구가 전 세계적으로 수행되고 있다. DFRCC는 경제적 효율성을 고려한다면 현재까지 구조물 전체 부분에 적용하기보다는 특별한 요소나 보수재료서 적용하는 것이 경쟁력이 있을 것으로 사료된다. 저자들은 DFRCC를 FRP-콘크리트 합성 바닥판과 습식 스프레이 보수공법에 적용하는 기술을 개발하고 있다. FRP-콘크리트 합성 바닥판에 적용할 경우에는 현장 적용하여 3개월 경과하더라도 구조성능 또는 내구성능이 저하되는 문제가 발생하지 않았고 매우 양호한 상태를 유지하였다. 그리고 국산 PVA 섬유 사용 DFRCC 보수 모르타르를 20년이 경과된 하수박스암거에 적용한 경우에는 한 결과, 일본산 PVA 섬유를 사용한 경우와 차이가 거의 없었다. 관련 규격인 KS F 4042의 압축 및 휨 강도기준을 모두 만족하는 것으로 나타났다. 이상과 같이 DFRCC를 구조물에 적용할 경우에는 구조물 종류에 따라서 경제적으로 성능 향상에 크게 기여할 수 있을 것으로 판단된다.