• 제목/요약/키워드: construction productivity

검색결과 1,121건 처리시간 0.025초

노반, 궤도분야 철도인프라 BIM 원형 라이브러리 구축 (A Development of Railway Infrastructure BIM Prototype Libraries for Roadbed and Track)

  • 박형진;서명배
    • 한국전산구조공학회논문집
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    • 제30권5호
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    • pp.461-468
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    • 2017
  • BIM 설계에서 라이브러리의 구축 및 활용은 매우 중요하다. 기존 컨텐츠의 재활용이 가능하므로, 설계를 보다 효과적이고 효율적으로 진행할 수 있다. 건축분야와 달리 토목분야, 특히 철도시설분야에서는 라이브러리의 구축 및 표준화가 미진하다. 따라서 본 연구에서는 철도시설분야에 3차원 객체 라이브러리를 구축하고 표준화하고자 한다. 철도시설물 분류체계 및 관련도면을 수집 및 분석한다. 분석된 표준도면의 항목과 분류체계 항목을 매칭하였다. 각 항목별로 라이브러리가 필요한지 여부와 그럴 경우 어떤 소프트웨어가 적절한지를 검토하였다. 사용가능한 소프트웨어는 주로 Civil 3D와 Revit 등으로 나타났다. 향후 이를 바탕으로 철도인프라 3차원 라이브러리의 속성 항목 및 명세서를 설계하고 라이브러리를 구축할 예정이다.

레이저/아크 하이브리드용접기술의 최신 동향 (Recent Technological Tendency of Laser/Arc Hybrid Welding)

  • 김영식;길상철
    • Journal of Welding and Joining
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    • 제31권2호
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    • pp.4-15
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    • 2013
  • The laser/arc hybrid welding process is a new process combining the laser beam and the arc as welding heat source. The laser beam and arc influence and assist one another. By application of hybrid welding, synergistic effects are achievable, and disadvantage of the respective processes can be compensated. The laser-arc hybrid welding process has good potential to extend the field of applications of laser technology, and provide significant improvements in weld quality and process efficiency in manufacturing applications. This review analyses the recent advances in the fundamental understanding of hybrid welding processes using the works of the data base of Web of Science (SCI-Expanded) since the 2000 year. The research activity on the hybrid welding has been become more actively since 2006, especially in China, presenting the most research papers in the world. Since the hybrid welding process was adopted in manufacturing of the automobile in Europe in the early of 2000's, its adopting is widely expanded in the field of manufacturing of automobile, ship building, steel construction and the other various industry. The hybrid welding process is expected to advance toward higher productivity, higher precision, higher reliability through the mixing of high power and flexible fiber laser or disk laser and digitalized pulsed arc source.

Construction of asm2 Deletion Mutant of Actinosynnema pretiosum and Medium Optimization for Ansamitocin P-3 Production Using Statistical Approach

  • Bandi Srinivasulu;Kim Yoon-Jung;Chang Yong-Keun;Shang Guang-Dong;Yu Tin-Wein;Floss Heinz G.
    • Journal of Microbiology and Biotechnology
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    • 제16권9호
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    • pp.1338-1346
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    • 2006
  • Ansamitocin P-3 is a potent antitumor agent produced by A. pretiosum. A deletion mutant of A. pretiosum was constructed by deleting the asm2 gene, a putative transcriptional repressor. The deletion mutant showed a 9-fold enhanced ansamitocin P-3 productivity. The response surface method with central composite design was employed to further optimize the culture medium composition for ansamitocin P-3 production by the deletion mutant. The concentrations of four medium ingredients, dextrin, maltose, cotton seed flour, and yeast extract, which have been reported as major components for ansamitocin production, were optimized through a series of flask culture experiments. The optimum concentrations of the selected factors were found to be dextrin 6.0%; maltose 3.0%; cotton seed flour 0.53%; and yeast extract 0.45%. The maximum titer of ansamitocin P-3 was 78.3 mg/l with the optimized composition, about 15-folds higher than the unoptimized titer of 5.0 mg/l obtained with YMG medium.

Control of Feed Rate Using Neurocontroller Incorporated with Genetic Algorithm in Fed-Batch Cultivation of Scutellaria baicalensis Georgi

  • Choi, Jeong-Woo;Lee, Woochang;Cho, Jin-Man;Kim, Young-Kee;Park, Soo-Yong;Lee, Won-Hong
    • Journal of Microbiology and Biotechnology
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    • 제12권4호
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    • pp.687-691
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    • 2002
  • To enhance the production of flavonoids [baicalin, wogonin-7-Ο-glucuronic acid (GA)], which are secondary metabolites of Scutellaria baicalensis Georgi(G.) plant cells, a multilayer perceptron control system was applied to regulate the substrate feeding in a fed-batch cultivation. The optimal profile for the substrate feeding rate in a fed-batch culture of S. baicalensis G. was determined by simulating a kinetic model using a genetic algorithm. Process variable profiles were then prepared for the construction of a multilayer perceptron controller that included massive parallelism, trainability, and fault tolerance. An error back-propagation algorithm was applied to train the multiplayer perceptron. The experimental results showed that neurocontrol incorporated with a genetic algorithm improved the flavonoid production compared with a simple fuzzy logic control system. Furthermore, the specific production yield and flavonoid productivity also increased.

간호리더십에 대한 개념 분석 (Concept Analysis of Nursing Leadership)

  • 김정숙;김윤민;장금성;김복남;정석희
    • 간호행정학회지
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    • 제21권5호
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    • pp.575-586
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    • 2015
  • Purpose: The purpose of this study was to provide a concept analysis of nursing leadership. Methods: The concept analysis process of Walker and Avant (2011) was used. A review of the literature was conducted using several databases, including PubMed, CINAHL, Ovid-Medline, DBpia, and KISS. The databases were searched using the following terms 'nursing leadership', 'nursing' & 'leadership', and 'nurse & 'leadership', and for studies published from January 2000 to March 2015. Strict inclusion and exclusion criteria were applied. Results: Analysis of these studies indicated nursing leadership attributes were individual growth, collaboration, nursing excellence, creative problem solving, and influence. The antecedents of nursing leadership were the individual maturity level, construction of mutual trust and confidential relationships, and a job requirement. The consequences were improvement in nursing productivity, development of a supportive work environment, and satisfaction with the nursing profession. Conclusion: The findings in this study provide a definite concept of nursing leadership. The findings also provide the theoretical evidence for the development of nursing leadership competencies in nursing students and professional nurses.

EJB기반 모바일 전자상거래 컴포넌트의 설계 및 구현 (Design and Implementation of EJB-based Components for Mobile Commerce)

  • 신동규;신동일;차석일;장철수;이경호;김중배
    • 정보처리학회논문지D
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    • 제9D권4호
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    • pp.703-712
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    • 2002
  • 컴포넌트 기술은 재사용성을 기반으로 어플리케이션 개발의 생산성을 높일 수 있어 소프트웨어를 신속하고 효과적으로 개발할 수 있는 기술로써 채택되고 있으며, 이들 중 EJB 컴포넌트는 자바를 기반으로 하며 산업계에서 널리 이용되고 있는 기술이다. 본 논문에서는 모바일 전자상거래 시스템의 구성 요소중 게시판과 쇼핑몰을 EJB 컴포넌트로 설계, 구현함으로써 재사용성과 상호운용성을 지원하는 구축 방안을 제시하였다.

신기능성 표면처리강판 제조기술의 최근 진보 (Recent Progress in New Functional Coating Technology)

  • 김태엽
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2012년도 춘계학술발표회 논문집
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    • pp.37-37
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    • 2012
  • The coated steels, mainly with zinc by either hot-dip galvanizing or electroplating, are widely used for panels of automotive, electrical appliances and construction, whose size of world market have reached 130 million tons in 2008. Current issues for the coated steels can be integrated in terms of high functionality, low cost, environment-friend and available resource. The best solution can be provided if thin layer coating with higher quality is produced by an eco-friendly process, and PVD, physical vapor deposition, can be an alternative practice to existing coating processes. PVD technologies have been very common ones in electronic and semiconductor industries, but recognized as non-profitable processes for the coated steels due to low process speed and lack of continuous operation skills. Systematic researches from 1990s in Europe, even though discouraged by a shutdown of the first Japanese PVD coating plant in 1999, have realized several continuous PVD coating plants, and also enhanced launching of developments in steel industries. To be successful with PVD coating technologies over existing ones, productivity to meet economics should be created from a highly sophisticated process. Some PVD technologies fit for the high-speed process will be introduced together with experiences from industrial applications.

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Schedule Optimization in Resource Leveling through Open BIM Based Computer Simulations

  • 김현주
    • 한국BIM학회 논문집
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    • 제9권2호
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    • pp.1-10
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    • 2019
  • In this research, schedule optimization is defined as balancing the number of workers while keeping the demand and needs of the project resources, creating the perfect schedule for each activity. Therefore, when one optimizes a schedule, multiple potentials of schedule changes are assessed to get an instant view of changes that avoid any over and under staffing while maximizing productivity levels for the available labor cost. Optimizing the number of workers in the scheduling process is not a simple task since it usually involves many different factors to be considered such as the development of quantity take-offs, cost estimating, scheduling, direct/indirect costs, and borrowing costs in cash flow while each factor affecting the others simultaneously. That is why the optimization process usually requires complex computational simulations/modeling. This research attempts to find an optimal selection of daily maximum workers in a project while considering the impacts of other factors at the same time through OPEN BIM based multiple computer simulations in resource leveling. This paper integrates several different processes such as quantity take-offs, cost estimating, and scheduling processes through computer aided simulations and prediction in generating/comparing different outcomes of each process. To achieve interoperability among different simulation processes, this research utilized data exchanges supported by building SMART-IFC effort in automating the data extraction and retrieval. Numerous computer simulations were run, which included necessary aspects of construction scheduling, to produce sufficient alternatives for a given project.

200kW 탑형 태양열발전시스템을 위한 Heliostat 반사면 구조 설계 (Design of Structure of Heliostat Reflective Surface for 200kW Tower Type Solar Thermal Power Plant)

  • 박영칠
    • 한국태양에너지학회 논문집
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    • 제31권2호
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    • pp.53-62
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    • 2011
  • Heliostat in the tower type solar thermal power plant is a sun tracking mirror system to reflect the solar energy to the receiver and the optical performance of it affects to the efficiency of whole power plant most significantly. Thus a proper design of structure of the heliostat reflective surface could be the most important step in the construction of such power plant. The work presented here is a design of structure of optical surface of heliostat, which will be used in 200kW solar thermal power plant. The receiver located at 43(m) high from ground in tower has $2{\times}2$(m) rectangular shape. We first developed the software tool to simulate the energy concentration characteristics of heliostat using the ray tracing technique. Then, the shape of heliostat reflective surface is designed with the consideration of heliostat's energy concentration characteristics, production cost and productivity. The designed heliostat's reflective surface has a structure formed by canting four of $1{\times}1$(m) rectangular flat plate mirror facet and the center of each mirror facet is located on the spherical surface, where the spherical surface is formulated by the mirror facet mounting frame.

Anti-Corrosion Performance and Applications of PosMAC® Steel

  • Sohn, Il-Ryoung;Kim, Tae-Chul;Ju, Gwang-Il;Kim, Myung-Soo;Kim, Jong-Sang
    • Corrosion Science and Technology
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    • 제20권1호
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    • pp.7-14
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    • 2021
  • PosMAC® is a brand of Zn-Mg-Al hot-dip coated steel sheet developed by POSCO. PosMAC® can form dense surface oxides in corrosive environments, providing advanced corrosion resistance compared to traditional Zn coatings such as GI and GA. PosMAC® 3.0 is available for construction and solar energy systems in severe outdoor environments. PosMAC®1.5 has better surface quality. It is suitable for automotive and home appliances. Compared to GI and GA, PosMAC® shows significantly less weight reduction due to corrosion, even with a lower coating thickness. Thin coating of PosMAC® provides advanced quality and productivity in arc welding applications due to its less generation of Zn fume and spatters. In repeated friction tests, PosMAC® showed lower surface friction coefficient than conventional coatings such as GA, GI, and lubricant film coated GA. Industrial demand for PosMAC® steel is expected to increase in the near future due to benefits of anti-corrosion and robust application performance of PosMAC® steel.