• 대한설비공학회:학술대회논문집
• /
• 대한설비공학회 2006년도 하계학술발표대회 논문집
• /
• pp.264-269
• /
• 2006

Efficient load management on natural gas is strongly required to allow stable and reasonable energy use. The present study investigated domestic and international cases for demand management of natural gas. The directions of load management were discussed. The reasonable evaluation methods of demand management were analyzed and specific evaluation items were suggested.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제45권2호
• /
• pp.231-242
• /
• 2006

National curriculum is very important for the future of nation. So, continuous efforts are needed to improve the national curriculum. This study examined the issues and the problems related with the 7th optional mathematics curriculum, and gave the message about th: methods of implementation. For this, we analyzed the result of the questionnaire survey which consisted in the question about the 7th optional mathematics curriculum. 264 high school mathematics teachers are participated in this survey. We found the result that the 7th optional mathematics curriculum has the problem in contents and management. So, this study gave not only the problem but also the various concrete methods for management of the 7th optional mathematics curriculum. We hope that mathematics education members research and argue about the optional mathematics curriculum for next curriculum.

• 산업공학
• /
• 제22권4호
• /
• pp.317-328
• /
• 2009

For a comprehensive understanding of human impact on a change of the global climate, it is necessary to obtain reliable information on man-induced fluxes of greenhouse gases (GHGs) into the atmosphere. Intergovernmental Panel on Climate Change (IPCC) guidelines (IPCC 1996, IPCC 2000, IPCC2006) provide the methods and procedures of estimating the national GHG emission inventories. Particularly, IPCC 2006 contains new chapter of key conceptions uncertainties, including the types of uncertainties and assessment methods of uncertainties in GHG emission inventories. In this paper, a compact and clear survey on volume 1 of IPCC 2006, which contains the general information on inventory compilation, uncertainty and guidance on the choice of methods, and QC/QA, is given with emphasis on uncertainty analysis.

• 대한산업공학회지
• /
• 제42권4호
• /
• pp.256-262
• /
• 2016

The Weibull is widely used in reliability analysis, and several studies have attempted to improve estimation of the distribution's parameters. least squares estimation (LSE) or Maximum likelihood estimation (MLE) are often used to estimate distribution parameters. However, it has been proven that Bayesian methods are more suitable for small sample sizes than LSE and MLE. In this work, the Weibull parameter estimation accuracy of LSE, MLE, and Bayesian method are compared for sample sets with 3 to 30 data points. The Bayesian method was most accurate for sample sizes under 25, and the accuracy of the Bayesian method was similar to LSE and MLE as the sample size increased.

• 지능정보연구
• /
• 제1권1호
• /
• pp.91-109
• /
• 1995

This paper compared four knowledge acquisition methods (namely, neural network, case-based reasoning, discriminant analysis, and covariance structure modeling) for allergic rhinitis. The data were collected from 444 patients with suspected allergic rhinitis who visited the Otorlaryngology Deduring 1991-1993. Among four knowledge acquisition methods, the discriminant model had the best overall diagnostic capability (78%) and the neural network had slightly lower rate(76%). This may be explained by the fact that neural network is essentially non-linear discriminant model. The discriminant model was also most accurate in predicting allergic rhinitis (88%). On the other hand, the CSM had the lowest overall accuracy rate (44%) perhaps due to smaller input data set. However, it was most accuate in predicting non-allergic rhinitis (82%).

• Industrial Engineering and Management Systems
• /
• 제7권1호
• /
• pp.23-33
• /
• 2008

This paper proposes an approach to monitoring and scheduling methods for repetitive MIMO-FIFO DESs. We use max-plus algebra for modeling and formulation, known as an effective approach for controller design for this type of system. Because a certain type of linear equations in max-plus algebra can represent the system's behavior, the principal concerns in past researches were how to solve the equations. However, the researches focused mainly on analyses of the relation between inputs and outputs of the system, which implies that the changes or the slacks of internal states were not clarified well. We first examine several properties of the corresponding state variables, which contribute to finding and tracing the float times in each process. Moreover, we provide a rescheduling method that can take into account delays or changes of the internal states. These methods would be useful in schedule control or progress management.

• 대한안전경영과학회지
• /
• 제18권4호
• /
• pp.161-169
• /
• 2016

In this research, we propose efficient demand forecasting scheme for intermittent demand. For this purpose, we first extensively analyze the drawbacks of the existing forecasting methods such as Croston method and Syntetos-Boylan approximation, then using these findings we propose the new demand forecasting method. Our goal is to develop forecasting method robust across many situations, not necessarily optimal for a limited number of specific situations. For this end, we adopt combining forecasting method that utilizes unbiased forecasting methods such as simple exponential smoothing and simple moving average. Various simulation results show that the proposed forecasting method performed better than the existing forecasting methods.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2021년도 봄 학술논문 발표대회
• /
• pp.311-312
• /
• 2021

As the number of deteriorated infrastructures increases, research on decision-making methods for efficient budget allocation is required. Thus, this study considered the application of utility theory for asset management of deteriorated infrastructure. In decision-making, methods that enable quantitative measurement were proposed, attributing the aging, economic feasibility, and ripple effects. This study is meaningful as a basic study of decision-making methods, and we will conduct research applied to case studies in the future.

• 국제학술발표논문집
• /
• The 5th International Conference on Construction Engineering and Project Management
• /
• pp.332-337
• /
• 2013

Various project delivery methods have been utilized by owners over the years to maximize project performance. The design-build delivery method is being increasingly used due to the advantages it can offer to an engineering construction industry. Numerous studies have advocated the use of design/build over the traditional design/bid/build delivery approach. This study represents comprehensive analysis of 40 projects from the construction industry and shows that design/build method may not provide all the benefits to project performance. This study found timesaving was a definitive advantage of design/build project delivery, but the positive effects of cost changes was not convincing. Based on the results of the study, the project management expertise and experience of the contractor may have a greater impact on project performance outcomes than focusing on project delivery strategy only.

• 품질경영학회지
• /
• 제25권3호
• /
• pp.96-107
• /
• 1997

The recent stream to reliability prediction is that it is totally inclusive in depth to consider even the operating and environmental condition at the level of finished goods as well as component itselves. In this study, firstly we present the reliability prediction methods by entire failure rate model which failure rate at the system level is added to the failure rate model at the component level. Secondly we build up the improved bases of reliability demonstration through a, pp.ication of Kaplan-Meier, Cumulative hazard, Johnson's methods as non-parametric and Maximum Likelihood Estimator under exponential & Weibull distribution as parametric. And also present the methods of curve fitting to piecewise failure rate under Weibull distribution, PRST (Probability Ratio Sequential Test), curve fitting to S-shaped reliability growth curve, computer programs of each methods. Lastly we show the practical for determination of optimal burn-in time as a method of reliability enhancement, and also verify the practical usefulness of the above study through the a, pp.ication of failure and test data during 1 year.