• Journal of Korean Society of Water and Wastewater
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• v.18 no.2
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• pp.145-154
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• 2004

A long-term sewer rehabilitation project consuming an enormous budget needs to be conducted systematically using an optimization skill. The optimal budgeting and ordering of priority for sewer rehabilitation projects are very important with respect to the effectiveness of investment. In this study, the sewer rehabilitation optimization model using fast-messy genetic algorithm is developed to suggest a schedule for optimal sewer rehabilitation in a subcatchment area by modifying the existing GOOSER$^{(R)}$ model having been developed using simple genetic algorithm. The sewer rehabilitation optimization model using fast-messy genetic algorithm can improve the speed converging to the optimal solution relative to GOOSER$^{(R)}$, suggesting that it is more advantageous to the sewer rehabilitation in a larger-scale subcatchment area than GOOSER.

• Journal of Korean Institute of Industrial Engineers
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• v.3 no.2
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• pp.57-62
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• 1977

We consider the problem of determining the optimal replacement policy of the items which deteriorate appreciably with time and become obsolete. Most of the conventional engineering economy models including the widely-accepted MAPI model assume linearity of technological improvement over time, in obtaining the economic lives of items and the net present values of the replacement alternatives under consideration. The main achievement of this paper is in that it successfully relaxes this strict linearity assumption to accommodate various other types of technological improvements in determining those values. Based on these results, we also include in this paper the mathematical models by which to determine the optimal replacement policies of items both under and without capital budgeting constraints.

• Asia-Pacific Journal of Business
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• v.13 no.4
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• pp.163-175
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• 2022

Purpose - This study introduces a methodology for finding the optimal tracking error of active stock funds. Tracking error is commonly used in risk budgeting techniques as a concept of cost for alpha creation. Design/methodology/approach - This study uses a post-optimal smart beta portfolio that maximizes alpha under the given tracking error constraint. Findings - As a result of the analysis, the smart beta strategy that maximized alpha under the constraint of 0.15% daily tracking error shows the highest IR. This means the maximum theoretically achievable efficiency. In this regard, a fixed-effect panel regression analysis is conducted to evaluate the active efficiency of domestic stock funds. In addition to control variables based on previous studies, the effect of tracking error on alpha is analyzed. The alpha used in this model is calculated using the smart beta portfolio according to the size of the constraint of the tracking error as a benchmark. Contrary to theoretical estimates, in Korea, the alpha performance is maximized under a daily tracking error of 0.1%. This indicates that the active efficiency of domestic equity funds is lower than the theoretical maximum. Research implications or Originality - Based on this study, it is expected that it can be used for active risk management of pension funds and performance evaluation of active strategies.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.1
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• pp.41-46
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• 2010

The latest multi-dimension spatial information technology is emerging its importance as material for carrying out efficient facilities management's supporting business about numerous facilities inside a university, budgeting decision-making supporting business such as operating expenses' budgeting and management, etc. and admission advertisement, etc. Accordingly, the present study selected an optimal location that can maximize spatial utilization of a building to be newly built by constructing multi-dimension spatial information for facilities management of a university, and executed a site suitability analysis according to transfer of a university symbol and a landscape analysis, etc. according to external environment change. As a result, it appeared that the effects such as prevention of duplicate investment and budget saving, etc. due to university's comfortable spatial composition and systematic comprehensive development & budgeting or decision-making support in case of execution, etc. caused by rationalization of facilities plan & management can be maximized.

• Journal of Agricultural Extension & Community Development
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• v.1 no.1
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• pp.11-13
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• 1994

This study surveys recent development in the service in Korea agricultural extension, including organization, human resource, budgeting, major works. The study, then, reviews the direction of new agricultural policy and the problems in extension service to present the optimal reform for the Agricultural Extension Service.

• Communications of the Korean Institute of Information Scientists and Engineers
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• v.4 no.2
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• pp.74-80
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• 1986

Budgeting system is a managerial planning which is the object and the standard of managerial activity. But we often see a budgeting svstem which is nonscientifie and nonpractical at present in Korea. So the object of this paper is that we try to estimate of which responsible management is executed. The technique of budget planning is a simulation based on computer processing. In simulation technique we seek a relative optimal amount that affects an object profit.

• Journal of Korean Institute of Industrial Engineers
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• v.6 no.2
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• pp.21-29
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• 1980

This paper deals with the capital budgeting problem of a firm where investments are risky and interrelated. The established models might be classified into two categories; One is the chance-constrained programming model and the other is the expected utility maximization model. The former has a rather limited objective function and does not consider the risk in direct manner. The latter, on the other hand, might lead to a wrong decision because it uses an approximate value of expected utility. This paper attempts to extend the applicability of the chance-constrained programming model by modifying its objective function into a more general form. The capital budgeting problem is formulated as a nonlinear 0-1 integer programming problem first, and is formulated into a linear 0-1 integer programming problem for finding a lower-bound solution of the original problem. The optimal solution of the original problem is then obtained by branch & bound algorithm.

• Journal of Korean Society for Quality Management
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• v.49 no.4
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• pp.467-482
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• 2021

Purpose: The main theme of this study is to determine the optimal control limit of conditional variance investigation by mathematical approach. According to the determination approach of control limit presented in this study, it is possible with only one parameter to calculate the control limit necessary for budgeting control system or standard costing system, in which the limit could not be set in advance, that's why it has the advantage of high practical application. Methods: This study followed the analytical methodology in terms of the decision model of information economics, Bayesian probability theory and Taguchi's quality loss function concept. Results: The function suggested by this study is as follows; ${\delta}{\leq}\frac{3}{2}(k+1)+\frac{2}{\frac{3}{2}(k+1)+\sqrt{\{\frac{3}{2}(k+1)\}^2}+4$ Conclusion: The results of this study will be able to contribute not only in practice of variance investigation requiring in the standard costing and budgeting system, but also in all fields dealing with variance investigation differences, for example, intangible services quality control that are difficult to specify tolerances (control limit) unlike tangible product, and internal information system audits where materiality standards cannot be specified unlike external accounting audits.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.223-224
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• 2023

Optimal fleet management in the planning stage is one of the most critical activities that guarantee successful construction projects. In South Korea, the construction standard production rate database (CSPRD) is normally employed. However, when it comes to a trade-off problem that involves decision-making on optimal sets of equipment to perform a certain task, the method will require the planners' in-depth knowledge and experience regarding the target process and a time consuming estimation of the performance of every possible scenario must be conducted for the deduction of the optimal fleet management. On this account, this research paper proposes a lightweight method of using mixed integer nonlinear programming (MINLP) in multi-objective problems based on CSPRD-based mathematical equations to assist planners in the preplanning stage of choosing the optimal sets of types and size machinery to efficiently arrange the construction scheduling and budgeting.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2018.05a
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• pp.72-73
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• 2018

The accuracy of contingency estimation plays an important role for dealing with the uncertainty of the financial success of construction project. Its' estimation may be used for various purposes such as schedule control, emergency resolve, and quality expense, etc. This paper presents a contingency estimation method which is schedule control specific. The method 1) implements stochastic EVMS, 2) detects a specific timing for schedule compression, 3) identifies an optimal strategy for shortening planned schedule, 4) finds a probability density function (PDF) of project cost overrun, and 5) estimates the optimal contingency cost based on the level of confidence. The method facilitates expeditious decisions involved in project budgeting. The validity of the method is confirmed by performing test case.