• 산업경영시스템학회지
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• 제9권13호
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• pp.17-22
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• 1986

Man-machine system is an integrated total system which is linked by functions of man and machine, and the value of the system is determined by its compatability. And it is able to evaluate the system value on the aspects of utility, availability, and cost benefit. The authors previously represented the methodology of system utility using transfer functions, and this paper successively discusses the reliability of man-machine system. The reliability estimation and evaluation methodologies are briefly mentioned, and some examples are shown in this paper.

• 국제학술발표논문집
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• The 6th International Conference on Construction Engineering and Project Management
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• pp.650-651
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• 2015

Value Engineering has been recognized as one of the construction management techniques for improving the value and benefits of whole project. However, due to the lack of the past data and inefficient free-thinking techniques, the idea generation during VE workshop is still inefficient and ineffective. Even though various studies related to theoretical methodology and technical systems relevant to database were conducted, VE team still mainly rely on their experience for idea generation. With this regard, this study suggests an approach of BIM-based idea bank and assesses its effectiveness by interviewing 20 VE experts in the industry. This approach covers the three steps of idea generation, consisting of 1) Developing BIM based VE database, 2) Generating VE ideas, 3) Updating VE ideas. The result showed that the proposed approach has great potentials to support VE team and improve the quality of VE ideas during creativity phase.

• Journal of Construction Engineering and Project Management
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• 제1권3호
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• pp.38-44
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• 2011

The central issue in this particular research is the seemingly inadequate achievement of optimum performance in the construction process, either with respect to value for money for the client and the entire construction supply chain or value in terms of the utility derived from built assets in spite of efforts by government and governmental bodies such as the Construction Industry Development Board (cidb) to increase industry performance. Therefore, based upon an extensive review of related literature, the paper reports on effects and causes of non-value adding activities in the construction industry in general, and South African construction in particular. The research findings indicate that activities that can be referred to as non-value activities are not only prevalent, but they can also be held responsible for performance related issues in terms of cost, time, quality and health and safety (H&S) in construction; and the exploration of pluralism in the research methodology may result in a robust model based upon the system dynamics approach.

• 대한산업공학회지
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• 제33권1호
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• pp.99-109
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• 2007

To realize process-driven management, so many companies have been launching business process managementsystems. Business process is collection of standardized and structured tasks inducing value creation of acompany. Moreover, it is recognized as one of significant intangible business assets to achieve competitiveadvantages. This research introduces a novel approach of workflow process analysis, which has more and moresignificance as process-aware information systems are spreading widely into a lot of companies, In this paper, amethodology of workflow clustering based on process similarity has been proposed. The purpose of workflowclustering is to analyze accumulated process definitions in order to assist design of new processes andimprovement of existing ones. The proposed methodology exploits measures of structural similarity of workflowprocesses.The methodology has been experimented with synthetic process models for illustrating the implicationofworkflow clustering.

• Computers and Concrete
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• 제19권6호
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• pp.737-744
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• 2017

Geopolymer Concrete is typically proportioned with activator solution leading to moderately high material cost. Such cost can be enduring in high value added applications especially when cost savings can be recognized in terms of reduction in size of the members. Proper material selection and mix proportioning can diminish the material cost. In the present investigation, a total of 27 mixes were arrived considering the mix parameters as liquid-binder ratio, slag content and sodium hydroxide concentration to study the mechanical properties of geopolymer concrete (GPC) mixes such as compressive strength, split tensile strength and flexural strength. The derived statistical Response Surface Methodology is beleaguered to develop cost effective GPC mixes. The estimated responses are not likely to contrast in linear mode with selected variables; a plan was selected to enable the model of any response in a quadratic manner. The results reveals that a fair correlation between the experimental and the predicted strengths.

• 산업경영시스템학회지
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• 제35권3호
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• pp.1-6
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• 2012

This paper aims to suggest a validity analysis model that would be helpful for local governments considering u-City construction projects and a methodology for them to promote build-transfer-lease (BTL) u-City projects. This methodology mainly uses quantitative and qualitative analysis based on the Value For Money (VFM) designed by the Public and Private Infrastructure Investment Management Center (PIMAC) under the Korea Development Institute (KDI). BTL projects requires a large amount of capital and involves long-term investments. Therefore, multi-faceted validity analysis is required for the success of a project. This study will enumerate various factors to be considered in the pre-analysis of validity of BTL projects and suggest a methodology to verify them. A case study of a BTL project promoted by Ansan City assisted in designing this study in detail.

• Journal of Microbiology and Biotechnology
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• 제17권12호
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• pp.1996-2004
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• 2007

In this study, the optimization of culture medium using a Sterigmatomyces elviae mutant was investigated using statistical analysis to increase the cell mass and lactosucrose ($^4G-{\beta}$-D-galactosylsucrose) production. In basal medium, the cell mass and lactosucrose production were 4.12 g/l and 140.91 g/l, respectively. However, because of the low cell mass and lactosucrose production, optimization of culture medium was carried out to increase the cell mass and lactosucrose production. Culture media were optimized by the S. elviae mutant using analysis of variance (ANOVA) and response surface methodology (RSM). Central composite designs using RSM were utilized in this investigation. Quadratic models were obtained for cell mass and lactosucrose production. In the case of cell mass, optimal components of the medium were as follows: sucrose 1.13%, yeast extract 0.99%, bactopeptone 2.96%, and ammonium sulfate 0.40%. The predicted maximum value of cell mass was about 5.20 g/l and its experimental value was 5.08 g/l. In the case of lactosucrose production, optimal components of the medium were as follows: sucrose 0.96%, yeast extract 1.2%, bactopeptone 3.0%, and ammonium sulfate 0.48%. Then, the predicted maximum value of lactosucrose production was about 194.12 g/l and the corresponding experimental value was about 183.78 g/l. Therefore, by culturing using predicted conditions, the real cell mass and lactosucrose production increased to 23.3% and 30.42%, respectively.

• 한국정밀공학회지
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• 제17권9호
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• pp.210-221
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• 2000

Plastic mold designers and frequently faced with optimizing multi-quality issues in injection molded parts. These issues are usually in conflict with each other and thus tradeoff needs to be made to reach a final compromised solution. in this study an automated injection molding design methodology has been developed to optimize multi-quality characteristics of injection molded parts. The features of the proposed methodology are as follows : first utility theory is applied to transform the original multi-objective problem into single-objective problem. Second is an implementation of a direct search-based injection molding optimization procedure with automated consideration of robustness against process variation. The modified complex method is used as a general optimization tool in this study. The developed methodology was applied to an actual mold design and the results showed that the methodology was useful through the CAE simulation using a commercial injection molding software package. Applied to production this study will be of immense value to companies in reducing the product development time and enhancing the product quality.

• 한국전자파학회논문지
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• 제30권5호
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• pp.356-364
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• 2019

최근 정부는 주파수의 효율적 이용을 위하여 이용자에게 주파수의 경제적 가치를 부과하겠다는 정책을 발표한 바있다. 이에 따라 다양한 용도의 주파수에 대한 경제적 가치를 측정하려는 시도가 있을 것으로 예상된다. 이러한 측면에서 본 연구는 주파수 공용통신 용도의 주파수의 경제적 가치를 최소비용대안 방식으로 측정하고자 하였다. 이 경우, 주파수의 가치는 해당 주파수가 주어지지 않을 경우 다른 방법으로 동 서비스를 제공하는데 들어가는 비용으로 측정할 수 있으며, 주파수 공용통신의 경우 이는 LTE 망을 통하여 제공하는데 소요되는 비용이 된다. 즉, TRS 용 주파수의 가치를 LTE 망 이용대가, 설비투자비용, 단말기 보조금, 보상금 등의 합계로 추정해 보았다. 본 연구의 결과는 향후 다른 용도의 주파수 이용대가 산정에도 시사점을 제공할 수 있을 것으로 기대된다.

• 적정기술학회지
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• 제5권2호
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• pp.82-90
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• 2019

반응표면분석법(Response surface methodology, RSM)의 Box-Benhken Design (BBD) 모델을 사용하여, 350℃로 가열한 골탄의 수중 불소 흡착 조건을 최적화하였다. 최적화 변수로 수온, pH, 접촉시간, 초기불소농도를 선택하였고, Box-Behnken Design에 의한 29회의 매트릭스 실험값으로부터 2차 반응 표면식을 얻었다. 이 반응 모델식의 결정계수(R²)는 0.9249였고 모델의 p-value는 <0.0001로 나타나 실험 변수들이 흡착결과에 매우 유의미한 영향을 미친다는 것을 알 수 있었다. 반응 표면식에 의해 예측된 골탄의 불소 흡착 최적 조건은 수온 39.68℃, pH 6.25, 접촉시간 88.81 min, 초기불소농도 14.64 mgF/L이었으며 이때의 불소 흡착용량(adsorption capacity)은 6.46 mgF/g인 것으로 분석되었다.