• 한국시뮬레이션학회논문지
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• 제20권2호
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• pp.19-27
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• 2011

본 연구에서는 스무딩된 주문정책이 리드타임, 만족율, 재고비용에 미치는 영향을 연구한다. 이를 위해 스무딩된 order up to 주문정책을 사용하는 하류업체와 make to order 방식을 사용하는 상류업체로 구성된 공급사슬을 사용한다. 스무딩을 하면 리드타임이 예상하는 바와 같이 감소된다. 그러나 스무딩에 의해 하류업체에서의 만족율이 감소하며 재고비용이 증가된다. 한편 상류업체 제조시간의 분산이 평균 제조시간보다 만족율 및 재고비용에 미치는 영향이 더 크므로, 상류업체 제조시간의 변동성을 최소화해야 한다.

• 플랜트 저널
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• 제7권3호
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• pp.48-64
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• 2011

In this work, risks in EPC project for overseas power plant projects are analyzed and risk management methods are suggested to reduce cost and to shorten time. 79% of risks occurred in the engineering phase for S project located in South-East Asia. The impact scales of risks on major project objectives which are cost, time, scope, and quality are analyzed as 3.5, 3.8, 2.7, and 3.7, respectively. The level of impact scales is very similar to each other except the impact scale of scope. The risk management methods suggested in this study have to be applied at the appropriate time to manage risks effectively. After that, risks are managed continuously by monitoring.

• 통합자연과학논문집
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• 제9권3호
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• pp.206-214
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• 2016

The basic goal of software development is to produce high quality software at low cost. Therefore, when to stop software testing and release the software product is a significant point in the software development. The software cost model is an effective tool used to help software developers control costs and determine the release time. In this paper, we discuss the cost model to apply all 6 models with consideration of time to remove errors, cost of removing each error and risk cost due to software failure. We show the impact of cost coefficients and parameter values on the expected total cost by changing the values and comparing the optimal release times.

• Journal of Information Processing Systems
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• 제17권3호
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• pp.473-488
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• 2021

The enterprise resource planning (ERP) system is a standardized and advanced business process that many companies are implementing now-a-days through customization. However, it affects the efficiency of operations as these customizations are based on uniqueness. In this study, we analyzed the impact of customized modules and processing time on customer service request (CSR), by utilizing the stacked CSR data during the construction and operation of ERP, focusing on small and medium-sized enterprises (SMEs). As a result, a positive correlation was found between unit companies and the length of ERP implementation; ERP modules and the length of ERP implementation; ERP modules and unit companies; and the type of ERP implementation and ERP module. In terms of CSR, a comparison of CSR processing time of CBO (customized business object) module and STD (standard) module revealed that while the five modules did not display statistically significant differences, one module demonstrated a statistically very significant difference. In sum, the analysis indicates that the CBO-type CSR and its processing cost are higher than those of STD-type CSR. These results indicate that companies planning to implement an ERP system should consider the ERP module and their customization ratio and level. It not only gives the theoretical validity that should be considered as an indicator for decision making when ERP is constructed, but also its implications on the impact of processing time suggesting that the maintenance costs and project scheduling of ERP software must also be considered. This study is the first to present the degree of impact on the operation and maintenance of customized modules based on actual data and can provide a theoretical basis for applying SW change ratio in the cost estimation of ERP system maintenance.

• International Journal of Internet, Broadcasting and Communication
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• 제13권2호
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• pp.36-42
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• 2021

This study aims to examine whether there are some differences in the cost stickiness of R&D expenses of IT companies before and after the COVID-19 crisis. Before COVID-19, IT companies did not reduce R&D expenses even if sales decreased, resulting in cost stickiness. As a result, it appears that during the COVID-19, IT companies adjust R&D expenses in proportion to changes in sales. This is interpreted as a reduction in R&D investment, which takes a long time to create results, in case of a decrease in sales due to uncertainty in future management performance due to the COVID-19 pandemic. In other words, during the COVID-19 risk period, IT companies, like other companies, reduced R&D expenses as sales decreased, resulting in reduced cost stickiness. This study differs from existing literature in that it examines the impact of the COVID-19 pandemic on the R&D expenditure behavior of companies in the IT industry.

• 영재교육연구
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• 제23권1호
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• pp.49-65
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• 2013

이 연구는 한국교육종단연구(KELS) 자료를 활용해 사교육 참여 경험이 수학성취도에 미치는 영향과 더불어 영재교육 참여경험이 수학성취도에 대한 사교육 효과에 미치는 영향을 선형 성장모형을 사용하여 분석하고자 하였다. 이를 위해 수학성취도 점수를 포함하고 있는 KELS 1차년도(2005년)부터 3차년도(2007년)의 자료 중 수학 교과에 대한 사교육 참여 여부, 주당 사교육 시간, 월 사교육비, 영재교육 경험 여부, 성별, 초등학교 6학년 성적 자료, 부모님의 월소득, 내재적 동기 그리고 자아효능감 자료가 사용되었다. 연구대상은 수학성취도 점수를 포함하여 연구목적에 포함된 변수들에 결측치가 있는 경우를 제외하여 최종적으로 4,435명으로 한정하였다. 연구결과 사교육 참여 경험이 더 많은 학생들이 다른 변수들을 통제하고도 수학성취도가 높았으나, 사교육 요인 중 사교육 시간과 사교육 비용의 경우 학년과의 상호작용이 수학성취도에 부적 영향을 미치는 것으로 나타났다. 이에 비하여 영재교육 참여경험은 수학성취도 향상 정도에는 부적 영향을 미쳤으나, 사교육 비용이 수학성취도에 미치는 효과에는 정적 영향을 미치는 것으로 나타났다. 즉, 영재교육 경험이 수학성취도에 대한 부정적 사교육 비용 효과에 대해 긍정적인 영향력을 간접적으로 보이고 있다는 점이다. 이러한 연구결과를 바탕으로 사교육이 수학성취도에 주는 영향 그리고 이러한 사교육 효과에 대한 영재교육경험의 영향과 의미를 논의하였다.

• International Journal of Quality Innovation
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• 제6권3호
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• pp.173-189
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• 2005

A life-cycle assessment (LCA) is based on the attention given to the environmental protection and concerning the possible impact while producing, making, and consuming products. It includes all environmental concerns and the potential impact of a product's life cycle from raw material procurement, manufacturing, usage, and disposal (that is, from cradle to grave). This study assesses the environmental impact of the ultra pure water process of semiconductor manufacturing by a life-cycle assessment in order to point out the heavy environmental impact process for industry when attempting a balanced point between production and environmental protection. The main purpose of this research is studying the development and application of this technology by setting the ultra pure water of semiconductor manufacturing as a target. We evaluate the environmental impact of the Precoat filter process and the Cation/Anion (C/A) filter process of an ultra pure water manufacturing process. The difference is filter material used produces different water quality and waste material, and has a significant, different environmental influence. Finally, we calculate the cost by engineering economics so as to analyze deeply the minimized environmental impact and suitable process that can be accepted by industry. The structure of this study is mainly combined with a life-cycle assessment by implementing analysis software, using SimaPro as a tool. We clearly understand the environmental impact of ultra pure water of semiconductor used and provide a promotion alternative to the heavy environmental impact items by calculating the environmental impact during a life cycle. At the same time, we specify the cost of reducing the environmental impact by a life-cycle cost analysis.

• 한국정보시스템학회지:정보시스템연구
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• 제10권2호
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• pp.129-150
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• 2001

In this study, we model a decentralized supply chain system which is managed by four types of centers, sequentially located: Retailer, Wholesaler, Distributor, and Factory Each center contributes to enhancing the performance of the supply chain system individually with its own local inventory information. Through experiments which are performed with a programmed simulation (like the MIT beer game), we investigate how the information lead time improvement in each center affects the whole system. And we show that the impact of the lead time improvement in the downstream, like retailers, affects more to the system than the one in the upstream, like factories, in a cost-effective way. Moreover, by using information lead time for each center, we analyze how much the extent of the improvement affects the whole system, especially for the total cost and the order level.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1694-1714
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• 2007

This study is to estimate economic benefits of Standardization R&D of Urban Rail System. Benefit was to be realized through standardization of main areas such as train vehicle, railway, power system, and signal system. To derive and calculate the quantitative benefit, the sources of economic impact was divided into three dimensions -operational cost savings, import substitution, and safety effects. Economic effect of the standardization was categorized based on a modified BSC model. Economic benefits from time and labor savings are converted into cost savings. Import substitution and investment multiplier effect have a positive impact in addition to cost savings. The estimation of the standardization R&D of Urban Rail System was conservatively estimated 370 billion Won. Cost effectiveness of standardized safety system was conservatively translated into economic benefit in this analysis. This study provides a practical guide to economic evaluation of the various railway R&D projects.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.371-375
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• 2015

Design-Build (DB) has gained in popularity in roadway projects due to its defining advantage to improve communication and fast-track project delivery. However, very little is known about the impact of change order frequency and occurrence timing pertaining to DB projects. The study analyzes their impacts on project time and cost performance by conducting a rigorous numerical analysis drawing on 530 3R (rehabilitation, reconstruction, and resurfacing) projects completed between 2002 and 2011 in Florida by using a multiple linear regression. The results indicate that DB outperformed Design-Bid-Build in project cost as well as time. Critically, the regression analysis signifies that earlier change order occurrence caused more unfavorable impacts on schedule and cost. The proposed analyses and models will lead to the improved ability of agencies to quickly and more reliably estimate the potential change order impacts on schedule and cost.