• 국제학술발표논문집
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• The 4th International Conference on Construction Engineering and Project Management Organized by the University of New South Wales
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• pp.256-261
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• 2011

Labor productivity is a significant factor related to control time, cost, and quality. Many researchers have developed models to define method of measuring the relationship between productivity and various constraints such as the size of working area, maximum working hours, and the crew composition. Most of the previous research has focused on estimating productivity; however, this research concentrates on estimating labor productivity and developing time and cost data for repetitive concrete pouring activity. In Korea, "Standard Estimating" only contains the average productivity data of the construction industry, and it is difficult to predict the time and cost of any particular project; hence, there are some errors in estimating duration and cost for individual activity and project. To address these issues, this research collects data, measures productivity, and develops time and cost data using labor productivity based on field conditions from the collected data. A probabilistic approach is also proposed to develop data. A case study is performed to validate this process using actual data collected from construction sites and it is possible that the result will be used as the EVMS baseline of cost management and schedule management.

• 대한안전경영과학회지
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• 제8권3호
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• pp.67-75
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• 2006

Scheduling of dismantling old research reactor need to consider time, cost and safety for the worker. The biggest issue when dismantling facility for research reactor is safety for the worker and cost. Large portion of a budget is spending for the labor cost. To save labor cost for the worker, reducing a lead time is inevitable. Several algorithms applied to reduce read time, and safety considered as the most important factor for this project. This research presents three different dismantling scheduling scenarios. Best scenario shows the specific scheduling for worker and machine, so that it could save time and cost.

• Journal of Construction Engineering and Project Management
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• 제10권1호
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• pp.16-32
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• 2020

Cost and time control of projects is important in preventing project failure. However, achieving effective cost and time control in practice is often challenging. The challenges of project cost and time control in practice are investigated by carrying out a questionnaire survey on the top 150 construction contractors in the UK followed by in-depth semi-structured interviews of practitioners from 15 construction companies in the country. Quantitative analysis reveals that design change is the most important factor inhibiting the ability of UK contractors from effectively controlling both the cost and time of construction projects. Four of the top five factors inhibiting effective cost control are also the top factors inhibiting effective time control albeit in a different order. These top factors-design changes, inaccurate evaluation of project time/duration, risk and uncertainty, non-performance of subcontractors and nominated suppliers were also found to be endogenous factors to the project. Additionally, qualitative analysis of the interviews reveals 16 key challenges to prevent for effective project cost and time control in practice. These are classified into four categorised based on where they stem from as follows; from the organisation (1. Lack of integration of cost and time during project control, 2. lack of management buy-in, 3. complicated project control systems and processes, 4. lack of a project control training regime); from the construction management/project management approach (5. Lapses in integration of interfaces, 6. project control not being implemented from the early stages of a project, 7. inefficient utilisation and control of labour, 8. limited time devoted to planning how a project will be controlled at the outset); from the client; (9. Excessive authorisation gates, 10. use of adversarial and non-collaborative forms of contracts, 11. communication problems within client set-up, 12. obstructive client representatives) and; from the project team (13. Lack of detailed/complete design, 14. lack of trust among the project partners, 15. limited time devoted to project control on site, 16. non-factual reporting). The study posits that knowledge of these project control inhibiting factors and challenges is the first step at ensuring they are avoided and enable the implementation of a more effective project cost and time control process in practice.

• Journal of Electrical Engineering and Technology
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• 제4권1호
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• pp.43-48
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• 2009

The purpose of the this paper is to make decision of the maintenance priority of power distribution system using Time-Varying Failure Rate(TVFR) with interruption cost. This paper emphasizes the practical use of the reliability indices and interruption cost. To make a decision of maintenance priority on power distribution system equipment, the quantification of the reliability level should be represented as a cost. In this paper, the TVFR of power distribution system equipment applied in this paper utilizes analytic method to use the historical data of KEPCO. From this result, the sensitivity analysis on TVFR of equipment was done for the priority, which represents that high priority of the equipment has more effect on system reliability, such as SAIDI or SAIFI, than other equipment. By this priority, the investment plan is established. In this result, customer interruption cost(CIC) could be extracted, and CIC is used as weighting factor to consider a importance of customer. After that, the result calculated the proposal method in this paper is compared with other priority method, such as lifetime, failure rate or only sensitivity.

• 방사성폐기물학회지
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• 제4권4호
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• pp.385-391
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• 2006

연구용원자로 해체비용은 해체대상물에 대한 특성 및 제원에 맞게 해체작업을 분류하고 구성요소를 설정하여 단위비용인자를 바탕으로 한 공학적 비용 산정 방법으로 해체비용을 산정한다. 연구용원자로에 대한 해체비용은 크게 인건비, 장비 및 재료비로 구성이 되는데 해체작업에 소요되는 인건비는 해체대상물에 소요되는 작업시간을 바탕으로 계산을 한다. 본 논문에서는 연구용원자로 해체비용 산정 시 인건비 계산에 필요한 단위비용인자 및 작업 난이도 인자를 산출하였다.

• 한국도로학회논문집
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• 제19권5호
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• pp.153-162
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• 2017

PURPOSES : This study was conducted to analyze the effects arising from extending the duration of nighttime road construction on improving road quality and durability. METHODS : Most previous studies estimating the social cost of various construction conditions did not consider road pavement cooling time as a factor in improving road pavement quality. This study investigated the feasibility of achieving higher road quality and durability by extending the duration of nighttime road construction time extension. For this investigation, the effects of such an extension on traffic conditions were analyzed based on micro-simulation studies and scenario-based cost-benefit analyses, using factors including traffic volume, delay, construction cost, and road pavement cooling time. RESULTS : The results of the traffic simulation studies and cost-benefit analyses indicate that the current road construction method that emphasizes completing nighttime road construction by 6 a.m. reduces pavement life while causing relatively little traffic delay. If the night construction time is instead extended to 2 p.m., road pavement lifetime is increased, reducing road re-construction cost. These savings are greater than the cost of congestion arising from extending the duration of nighttime construction. CONCLUSIONS : The current nighttime construction durations need to be extended in order to efficiently manage roads and reduce road management costs.

• 한국산학기술학회논문지
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• 제16권9호
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• pp.5843-5849
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• 2015

본 연구는 단감농가의 생산비절감방안 모색을 위해 생산요소 수요구조를 분석했다. 2001~2013년간 농산물소득조사 원자료를 이용해 초월대수 비용함수를 추정하고 노동, 자본, 중간투입재간 가격 및 대체탄력성을 계측했다. 분석결과 생산요소 모두 가격변화에 따른 수요변화가 크지 않고 특히 비용부담이 가장 큰 노동의 가격상승에 따른 타 생산요소의 대체성이 낮아 구조적으로 단기간에 노동 수요를 줄이기는 어려운 것으로 나타났다. 이는, 생산비절감을 위해서는 노동에 비해 수요가 탄력적인 중간투입재, 특히 탄력성이 큰 비료와 기타재료비를 중심으로 비용절감이 이뤄져야함을 시사한다.

• 대한안전경영과학회지
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• 제1권1호
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• pp.135-143
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• 1999

This paper discusses an optimal burn-in procedure to minimize total costs based on the assumption that the failure rate pattern follows a bimodal mixed Weibull distribution. The procedure will consider warranty period as a factor of the total expected bum-in cost. A cost model is formulated to find the optimal burn-in time that minimizes the expected burn-in cost. Conditional reliability for warranty period will be discussed. An illustrative example is included to show how to use the cost model in practice.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2015년도 추계학술대회
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• pp.241-242
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• 2015

According to globalization of world economy on distribution and sales, logistics and transportation parts are play important role. Especially, it important to know and study how to choose right transport route and which is the key factor of route choice model in multimodal transport system. Thus this study aims to consider 4 main factors: cost, delivery time, freight, and logistics service factors additionally dividing into 13 sub factors and object is forwarders between Mongolia and Korean freight transport. The survey is based on AHP through interview with company officials. The paper provides empirical insights about current status of Mongolian forwarders and difference of the important factors between transportation modes. Result shows that time factor is role factor to choose transport route and then cost factors. Additionally, this study shows 2 different route choose factors between air transport and shipping transport forwarders.

• 정보처리학회논문지D
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• 제15D권1호
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• pp.61-72
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• 2008

성공적인 소프트웨어 프로젝트 수행을 결정짓는 중요한 작업 중의 하나는 프로젝트 개발 초기에 소프트웨어 개발 비용을 정확하게 산정하는 것이다. 정확한 산정을 위해서는 빠르게 변화하고 있는 개발 환경 및 기술 변화에 따른 변경 요인을 비용 산정 과정 시 반영시켜야 하며 이를 위해서는 적절한 보정계수 선정과 보정계수 값 적용이 중요시된다. 이에 본 논문에서는 소프트웨어 개발비 대가기준을 위한 어플리케이션 유형 보정계수와 언어 보정계수 산정을 위해 AHP 기법을 적용하였다. 또한, 민감도 분석을 통하여 각 판단 기준이 보정계수에 미치는 영향을조사하였다. 결론적으로, 어플리케이션 유형 보정계수 값은 처리 복잡도에 비해 데이터관리 복잡도와 제어 복잡도에 민감하게 반응하며 또한, 언어 보정계수 값은 디버깅 시간에 비해 개발인력의 보편성과 개발코딩 시간에 더 민감하게 반응하였다. 향후, 연구과제로는 국내의 소프트웨어 개발 환경과 기술을 적절히 반영시킬 수 있는 추가적인 보정계수 결정과 적절한 보정계수 값 조정에 대하여 연구할 것이다. 또한, 언어 보정계수에서는 구체적인 프로그래밍 언어를 들어 좀더 세부적으로 구분한 후 보정계수를 산정하고자 한다.