• Title/Summary/Keyword: contractor

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Application of CFD Program for Analyzing the Hydrodynamic Characteristics of Baffled PAC Contactor (격벽식 분말활성탄 접촉조의 흐름해석을 위한 전산유체역학 프로그램의 적용)

  • Ahn, Chang-Jin;Ahn, Sang-Jin
    • Journal of Korea Water Resources Association
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    • v.35 no.2
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    • pp.221-229
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    • 2002
  • For the efficient design of baffled Powdered activated carbon(PAC) contractor, which has been widely used in water treatment plant(WTP) against the algae-related odor problems, a CFD(computational fluid dynamics) program was applied. In order to verify the performance of FLOW-3D program, the previously reported results of tracer tests from a pilot-scale PAC contractor(working volume of 288 liters) were compared to those from FLOW 3D. The results of FLOW-3D simulation were very similar to those from tracer tests conducted with the Pilot-scale PAC contactor. On the other hand, the hydrodynamic characteristics of baffled contractor in the P-WTP were simulated by using FLOW-3D. Simulation results on the distribution of PAC particles showed that there are some stagnant parts in the back side of baffles in which PAC Particles are not present. These stagnant parts might decrease the adsorption capacity of PAC particles. When the baffles were changed to maze-type intra-basin baffling, PAC particles were evenly distributed and the amount of stagnant parts reduced. In conclusion, it is anticipated that FLOW-3D simulation could be a viab1e tool for analyzing the hydrodynamic characteristics of structures used in drinking water treatment plant.

Benchmarking of US General Contractor's Pre-construction Services for a CM at Risk Project to Improve Contractor's Competitiveness (책임형 CM사 경쟁력 확보 및 선진화를 위한 미국 건설사의 시공이전단계 서비스 벤치마킹 연구)

  • Lee, Chang-Jae;Lee, Sang-Hyo;Ahn, Yong-Han
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.21 no.3
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    • pp.9-18
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    • 2017
  • Construction Management at Risk (CMAR) is a project delivery method that enables CM companies to deliver projects at a Guaranteed Maximum Price (GMP). General contractors can apply CMAR from the initial design phase right through the construction phase to reduce risks and improve project performance. One of the major advantages CMAR offers is that it permits a general contractor to provide a comprehensive suite of preconstruction services, including estimating, a constructability review, value engineering, drawings and a specification review, green building, and Building Information Modeling(BIM), among others. However, general contractors in South Korea currently provide only limited preconstruction services using CMAR because few CMAR projects have yet been implemented in Korea and their experience using the method is therefore limited. This benchmark study of how foreign general contractors utilize CMAR in their projects, particularly during the preconstruction process, its purpose, and the roles and responsibilities of each of the different participants in successful implementations thus provides invaluable information and will serve as a useful guide for Korean contractors seeking to incorporate CMAR preconstruction services in their projects and thus improve the competitiveness of their construction businesses.

A Study on Qualification for Possessory Lien on and Auction of Unregistered Buildings (미완성건물의 유치권 및 강제경매 대상적격에 관한 연구)

  • Lee, Jae Seog;Jung, Bo Seon;Lee, Sang Youb
    • Korea Real Estate Review
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    • v.28 no.4
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    • pp.53-62
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    • 2018
  • When the contractor does not receive payment for his work due to the client's funding default, he can take various legal measures against the client, in addition to refusing to transfer the building under construction to the client. To claim top payment priority and to demand the equal enforcement of the law by applying for compulsory auction or auction by exercising the right of lien, the contractor should know the construction phase or the point in time when he could exercise a lien or apply for a forced auction of the unregistered building. This study was conducted to examine qualification for lien and auction of an unregistered building. First, the general criteria for qualification for lien from qualification for ownership were examined. This means that an unregistered building can be subject to lien from a certain point in time in the construction phase, where the ownership is qualified as an independent real estate with minimal pillars, roofs, and walls. Second, the contents of the narrow and broad auction qualification were analyzed. As the contractor can select the appropriate legal means to reimburse the construction cost for the unregistered building, the results of this study are expected to provide the bases for qualification for lien on and auction of unregistered buildings.

Risk Assessment on the Water BOT Business Participation in China : Domestic EPC Contractor's View (해외기업의 중국 수처리 BOT시장 참여 저해 위험요인 분석 : 국내 EPC 건설기업의 관점)

  • Choi, Jae-ho;Li, Shoushuang;Lee, Seungho
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.5D
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    • pp.695-703
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    • 2008
  • China water market has huge potential for increased use of BOT mode and one of the most attractive markets of doing business. However, the current China water BOT market shows that many foreign companies are retreating from the market while Chinese water companies fast growing. From the view no domestic companies have track records in China BOT water market, the research identified twenty market access barriers in terms of construction laws, regulations, BOT-related policy and the recent market situation. These are evaluated based on interview results with 10 professionals direct or indirect having a China water BOT experience. All the factors are found to be highly influential to foreign company's decision on the market participation. Among those, no fixed return policy and low water price, difficulty in water price adjustment and approval, and no government guarantees, all directly related to the project viability and under the control of government, were the most critical factors, implying government's role is the key in increasing the market competition by attracting more foreign participation on the market. In addition, new construction law regulating foreign EPC contractor's construction work, namely Decree 113, and requirement of applying competitive bidding in selecting EPC contractor in a BOT project are also considered signigicant barriers on foreign participation, which contradicts international norm and therefore necessitates an adjustment on current decision process in domestic companies.

Apportionment of Liquidated Damages and Compensation for Delay Damages in Domestic Construction Project : Analysis and Improvement (국내 현행 공기지연 책임에 따른 지체상금 및 손실보상의 문제점 및 개선방안)

  • Kim, Kyong Ju;Kim, Kyoungmin;Kim, Jong Inn;Wei, Ameng;Kim, Eu Wang
    • Korean Journal of Construction Engineering and Management
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    • v.24 no.1
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    • pp.12-20
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    • 2023
  • To calculate the amount of owner-caused and contractor-caused delays based on a simplified delay analysis, which has been customarily used in Korea, has a limitation in reflecting the impact of the concurrent delay and the acceleration work. It also resulted in the apportionment of liquidated damages by applying the ratio of the number of delays between the owner and the contractor. This study analyzes that the conventional method does not meet the international standards. In order to improve the problem of construction delay analysis and the apportionment of liquidated damages based on it, owner delays, contractor delays, concurrent delays, and the impact of acceleration should be analyzed together. This study suggests that in the apportionment of liquidated damages, the extension of time should be extended by the sum of concurrent delays and the owner-caused delays, and liquidated damages should be imposed on delays incurred after the extension of time. It can be seen that it conforms to the international standards. The results of this study are expected to contribute to improving the problems of delay analysis and liquidated damages calculation, which have been conventionally accepted.

Design and Implementation of an Ethereum-Based Deliverables Management System for Public Information Software Project (이더리움 기반 공공정보 소프트웨어 사업산출물 관리 시스템 설계 및 구현)

  • Lee, Eun Ju;Kim, Jin Wook
    • KIPS Transactions on Computer and Communication Systems
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    • v.11 no.6
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    • pp.175-184
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    • 2022
  • Blockchain is being studied in various fields such as logistics, fintech, medical care, and the public sector. In the public information software project, some deliverables are omitted because the developed deliverables and the deliverables requested by the project management methodology do not match, and an additional process is required for payment. In this paper, we propose the deliverables management system for public information software project which is configured a distributed environment using the Ethereum blockchain and which has an automatic payment system only when all deliverables are approved. This system can keep the service available in case of system failure, provide transparency and traceability of deliverables management, and can reduce conflicts between the ordering company and the contractor through automatic payment. In this system, the information of deliverables is stored in the blockchain, and the deliverables that their file name is the hash value calculated by using the version information and the hash value of the previous version deliverable, are stored in the SFTP server. Experimental results show that the hash value of the deliverables registered by the contractor is correct, the file name of the deliverables stored in the SFTP server is the same as the hash value registered in the Ethereum blockchain, and the payment is made automatically to the Ethereum address of the contractor when all deliverables are approved.

A Study on the Application of Performance Based Logistics (성과기반군수(PBL) 적용방안 연구)

  • Choi, Seok-Cheol
    • Journal of the Korea Institute of Military Science and Technology
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    • v.11 no.2
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    • pp.88-94
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    • 2008
  • It is very important for weapon systems to manage the logistic support for the better combat readiness. Therefore, in this paper we review the issues of logistic support and suggest alternatives to effectively manage the logistic support for weapon systems by using performance based logistics, especially during operations and support phase.

A Study on the Development of Design Information CITIS Prototype (설계정보 CITIS 프로토타입 구현에 관한 연구)

  • 박정선;김성희
    • The Journal of Information Technology and Database
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    • v.6 no.1
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    • pp.47-57
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    • 1999
  • CITIS(Contractor Integrated Technical Information Service) is a service standard which specifies guidelines which are required for the fulfillment of a contract between a purchaser and a supplier. It was initiated as a military standard and is now becoming a commercial standard. In this paper, we propose how the guidelines, which were usually developed by Client/Server methods in previous works, can be implemented in WWW environments, and show a prototype which can be used for the confirmation of CAD drawings between contractors(purchaser and provider). We have a hope our study can provide a small foundation for the building of CITIS references.

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한국의 IQUE 적용방향 제시 - 항공분야를 중심으로 -

  • Jang, Sang-Yong
    • Journal of Korean Society for Quality Management
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    • v.21 no.2
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    • pp.27-34
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    • 1993
  • Quality Assurance Method of Defense Logistics Agency, U. S. A., was changed from Contract Quality Assurance Program to In-Plant Quality Evaluation in May, 1990. IQUE focuses on working with contractor in spirit of team work to measure and continuously improve processes and resulting product quality. The goals are to achieve customer satisfaction, improved product quality, and a reduction in the costs of items and ownership. It is suggested to adopt and apply the IQUE method to the effective accomplishment of Korean aircraft projects.

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Snow Tunnelling Project at the South Pole (남극 극지점 기지에서의 얼음 터널 프로젝트)

  • 지왕률
    • Tunnel and Underground Space
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    • v.13 no.1
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    • pp.1-5
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    • 2003
  • The United States Antarctic program (USAP) through its principal Support Contractor Raytheon polar Services Co. (RPSC), has recently finished a 3 years projects, almost 936m length of underground utility tunnels at Amundsen-Scott station. It accommodates the piping that conveys fresh water from current well sites, as well as waste water to repositories in abandoned wells. The under snow tunnels allow year-round access for system operations and maintenance.