Purpose Present Worth (PW) and Internal Rate of Return (IRR) are two popular economic decision criteria in engineering economic analysis, but PW is preferred to IRR because of several deficiencies including multiple internal rates of return (MROR).
Research in MROR has mainly focused on two areas: conditions for MROR occurrence and unique positive IRR, and solutions to MROR. This paper discusses MROR problems in depth. Methods In two areas of MROR, main and recent research streams are reviewed and illustrated with numerical examples. Also, a concrete measure to clarify the meaning of AIRR(Average IRR) proposed by Magni(2010) to resolve several problems of IRR is provided.
Results Scopes and levels to cover MROR problems in textbooks of engineering economy (EE) field are surveyed and a new pedagogical proposal for instructors to teach MROR problems in EE class is presented.
Conclusion Despite several drawbacks including MROR, surveys for managers have consistently shown that substantial practitioners still favor IRR. Results and proposals in this article will be helpful to enhance the study achievement for IRR in EE class of university.

Purpose The purpose of this paper is to improve the performance of HS meta-heuristic optimization algorithm.
Methods Based on the two problems consciousness against the conventional harmony improvisation process, a new pitch adjustment referring to the best harmony is introduced and developed. For the test, the proposed strategy is applied to the optimization test functions.
Results The propose method is applied to several simple and complex optimization test function. The results shows that the proposed strategy surpasses the performance of conventional method.
Conclusion The new strategy works very well and algorithm parameters tunning is needed to improve further the performance of the new method.

Purpose By developing the key success processes of the projects of domestic EPC companies participating in overseas power generation and petrochemical projects and presenting them to academics and industry, it will contribute to the study of project management and improve the international competitiveness by enhancing the project execution capability of domestic EPC companies.
Methods The research method is to compare the proportion of each process to 49 processes functions in 10 knowledge areas and 5 process groups presented by PMBOK 6th edition by a group of experts with more than 20 years of experience in the representative plant EPC companies in Korea. After collecting expert opinion analysis data, we used the Analytic Hierarchy Process (AHP) technique and tiered and prioritized for each stage of project execution.
Results The existing qualitative method is quantitatively analyzed to determine priorities for key success factors of project management and methodology accordingly.
Conclusion By prioritizing the detailed elements of the EPC project management process in the overseas power generation and petrochemical sectors, we present strategic directions for the execution of overseas projects by domestic EPC companies.

Purpose This paper was studied to confirm the possibility of classifying the thickness shape of the electrolyte thin film coating in the width direction using several supervised learning methods.
Methods In order to evaluate the coating uniformity, data on the shape of the coating thickness was collected through online non-destructive thickness measurement. After defining classes for coating patterns in the width direction through exploratory analysis, supervised learning algorithms such as Random Forest, SVM, KNN, GNB, and MLP were used to evaluate and compare the accuracy of the models.
Results In the case of Random Forest, SVM, KNN, and GNB algorithms, classification into 5 classes has higher accuracy than those classified into 9 classes. The MLP algorithm showed higher classification accuracy in 9 classes than in 5 classes. It was confirmed that the classification accuracy can be achieved more than 80% by adjusting the classification class
Conclusion The results illustrate that it is possible to classify the shape of the electrolyte thin film coating thickness in the width direction through supervised learning.

Purpose This study analyzes small- and medium-sized manufacturing corporations' bankruptcy problem based on financial ratio variables. The analysis is done using Decision Tree model, Random Forest model, and Gradient Boosting model. Model performance is evaluated with correct classification rate, false negative rate, and false positive rate.
Methods Both decision tree ensemble models outperform basic decision tree model in terms of correct classification rate. Gradient Boosting model is more consistent in prediction than Random Forest model. Regarding false negative rate, Random Forest model produces least error and Gradient Boosting model is second best with higher consistency.
Results Mean decrease accuracy index resulted from Random Forest model indicates that important input variables are ordered as net profit over sales revenue, sales over financial expenses, total equity over net working capital, and turnover rate of management assets. Influential input variables are turned out, in order, to be net profit over sales revenue, total equity over net working capital, sales over financial expenses, and operating profit over sales revenue, according to mean decrease gini.
Conclusion Based on the study findings, this study insists that manufacturing corporations should continuously monitor the change in financial ratio variables that are identified important antecedents for bankruptcy possibility.

Purpose The purpose of this study is to clarify the effect of software freelancers on multiple commitments according to the Supreme Court's criteria for determining worker, and to find the moderating effect of employability.
Methods The research method was empirical analysis through a questionnaire of 190 freelancers.
Results The results of the study revealed that when freelancers are recognized as workers with high human dependency, there is a positive(+) relationship with job commitment, and when recognized as workers with high economic dependency. In addition, it was found that internal employability demonstrates the moderating effect between workers and organizational commitment
Conclusion The conclusion of this study will help to improve the quality of project outcomes by presenting a plan to increase immersion in the case of companies hiring software freelancers.

Purpose This study presents a combined model of Fault Tree Analysis (FTA) and Failure Mode and Effects Analysis (FMEA) using evidence theory and Fuzzy Bayesian Network (FBN) under uncertain circumstances which are caused by the presence of incompleteness, randomness and ambiguity of failure modes.
Methods In order to identify the critical failure modes according to the multi-level FTA-FMEA, the Trapezoidal Distribution-Type Basic Belief Assignment (TrDTBBA) is used to consider the viewpoints of experts and to resolve the conflicts of evidence The proposed FTA-FMEA-FBN model derives fuzzy posterior probabilities to implement fault diagnosis approach which is more suitable than fuzzy prior probabilities when conducting qualitative reasoning of vague probability.
Results A novel method for identifying the critical failure modes according to the level of hierarchical Bill of Material (BOM) is based on the proposed FTA-FMEA-FBN integrated model that illustrates chassis system consisting of 6 components, 4 modules and 6 parts.
Conclusion This suggested FTA-FMEA-FBN model is convenient for a risk evaluation in the following uncertain circumstances: 1) The information of failure modes are incomplete, 2) The numbers of failure modes comprised of three levels are too abundant, 3) The probabilities of failure modes have a lack of quantification data. The fusion strategy of those three risk techniques implements computational efficiency and provides a synergistic effect to accurately identify the critical failure modes under uncertain circumstances.

This paper explores the network revenue management problem where a firm sells products composed of multiple resources. Unlike the traditional network revenue management problem, the products have time and precedence constraints. This means that some products may be infeasible to deliver. To filter out those infeasible products, this paper proposes a simple linear programming. The firm starts the sales horizon only with the feasible products. The dynamic programming can be formulated to have the optimal policy, but it may suffer from the curse of dimensionality. To overcome this difficulty, this paper proposes the linear programming based heuristic. The numerical study shows that the heuristic can save the computation time greatly while providing a reasonably good solution.

Purpose Establish a plan to increase technology commercialization capability based on absorption capability and R&D capability
Methods Analyze causal relationship between factors through structural equation model
Results Absorption capability has a significant effect on both R&D capability and technology commercialization capability, but R&D capability has an effect on the productization capability of the technology commercialization capability, but not the manufacturing capability and marketing capability of the technology commercialization capability.
Conclusion First, it is important to increase the absorption capacity in order to increase the R&D capacity. Second, in order to acquire external knowledge and information, various networks with the outside must be formed. Third, it is necessary to establish clear goals for R&D and practice it with manpower, equipment, and funds.

Purpose The purpose of this study is to analyze the changes in the technology convergence network of national R&D patent performance and the differences in technology convergence research trends between independent R&D and collaborative R&D.
Methods Co-occurrence networks have been established in which multiple International Patent Classification (IPC) codes appear per patent in 2014 and 2017. Then, network analysis methods and QAP (Quadratic Assignment Procedure) analysis methods have been used in this study.
Results As a result, this study shows that the degree of linkage between technologies related to national R&D projects has increased over time. The main fields of technology convergence research have been changed to ICT fields such as digital and data (G06Q, G06F) and bio fields such as food (A23L) and cosmetics (A61Q). The Ministry of Agriculture, Food and Rural Affairs actively conducts convergence research by introducing new technologies such as ICT. The Ministry of Health and Welfare actively conducts convergence research in the field of bio-health.
Conclusion This study showed the changes and characteristics of technology networks of convergence R&D and collaborative R&D. The results of this study are expected to be used as a guideline for decision making in the government's R&D policies.