• Journal of the Korea Institute of Military Science and Technology
• /
• v.3 no.1
• /
• pp.26-37
• /
• 2000

This research paper deals with the problem of determining the optimal life time in terms of economical sense for a self-propelled artillery. Equivalent Annual Cost Method(EACM) is used to evaluate the optimal life time, based on the acquisition cost, and the operation and maintenance cost. It is assumed that the operation and maintenance cost includes the costs for spare parts, petroleum and ammunition for training. From the result of this study, the optimal life time for a self-propelled artillery is between 13.9 years and 16.1 years with 95% confidence interval.

• Proceedings of the KIEE Conference
• /
• 2000.11a
• /
• pp.67-69
• /
• 2000

This paper deals with a method for determining an optimal operation strategy of dispersed generating sources. For effective utilization of dispersed generating sources, it is indispensable to consider their thermal merits in addition to electric power. And then the optimal operation of these sources can be determined easily by the principle of equal incremental fuel cost. This paper presents an priority method to decide the optimal location of those sources in power systems about the whole year. The validity of the proposed algorithms are demonstrated using a model system.

• Journal of Korean Society for Quality Management
• /
• v.43 no.3
• /
• pp.453-466
• /
• 2015

Purpose: The purpose of this study is to design a systematic method to estimate optimal operation conditions of design variables for an electronic device alignment system. Method: The 2-level factorial design and the central composite design are used in order to plan experiments. Based on the experiment results, a regression model is established to find optimal conditions for the design variables. Results: 3 of 5 design variables are selected as major factors that affect the alignment system significantly. The optimized condition for each variable is estimated by using a sequential experiment plan and a quadratic regression model. Conclusion: The method designed in this study provides an efficient and systematic plan to select the optimized operation condition for the design variables. The method is expected to improve inspection accuracy of the system and reduce the development cost and period.

• IE interfaces
• /
• v.13 no.4
• /
• pp.680-687
• /
• 2000

The objectives of this research are to establish the operation scheduling and the preventive maintenance system in order to optimize the operation of mailing center. For the optimal operation scheduling of mailing process, the existing workflow of mailing process and that of required time are investigated prior to simulation modeling. The simulation experiments are conducted to increase the nextday delivery rate. The best alternative whose nextday delivery rate up to 100% is selected based the AHP(Analytic Hierarchy Process) method. The optimal work scheduling of all mailing centers are also presented. In addition, the CMMS(Computerized Maintenance Management System) for preventive maintenance is introduced for efficient operation of highly automated facilities of mailing center.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.19 no.5
• /
• pp.463-469
• /
• 2014

This paper proposes a maximum torque operation strategy for the direct torque control of a surface-mounted permanent-magnet synchronous motor (SPMSM). The proposed method analyzes the available operation region of the stator flux of the SPMSM under voltage and current constraints. Based on this analysis, the optimal stator flux trajectory that yields the maximum torque is obtained across the entire operation region, including constant torque and constant power regions. The proposed strategy is also applicable in the flux-weakening region II operation of the SPMSM, which has no speed limit. The validity of the proposed method is verified through experiments conducted on an 800 W SPMSM drive system.

• Journal of Energy Engineering
• /
• v.7 no.1
• /
• pp.81-88
• /
• 1998

This paper describes the method decide to optimal sizing and operation scheduling of total cogeneration system which is interconnected with cogeneration unit of utility and auxiliary thermal devices of heating company. Optimal sizing and operation scheduling is established in order to minimize the fuel cost under national viewpoint. Simulations are carried out to show the reliability of method suggested by seasons and kinds. The simulated results can be effectively used as the guideline of operation scheduling between the utility and the heating company.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2007.05a
• /
• pp.224-228
• /
• 2007

It is focused on a methodology to establish a optimal inspection cycle of electrical facility of railroad Decision method of optimal inspection cycle is a process which establishes maintenance plan for facilities' immanent function as using reliability theory in operation term In order to ensure normal operation in a given condition, the decision method is logical for selecting effective maintenance plan to consider characteristic of system In estimation of failure rate, critical facility is selected firstly. After that, proper distribution function on each facility is decided to investigate distribution function for extraction of failure rate. Next, cost produced by the case that facility's failure is occurred is surveyed. Finally, maintenance method developed until now is investigated, before suitable model for the facility applying maintenance method is developed, and that maintenance decision is made. Therefore, this process is the method to find optimal inspection cycle for reasonable cost and effective reliability on facility.

• Journal of Electrical Engineering and Technology
• /
• v.8 no.4
• /
• pp.712-718
• /
• 2013

With the development of industry and the improvement of living standards, better quality in power electric service is required more than ever before. This paper deals with the optimal algorithms for voltage regulation in the case where Distributed Storage and Generation (DSG) systems are operated in distribution systems. It is very difficult to handle the interconnection issues for proper voltage managements, because the randomness of the load variations and the irregular operation of DSG should be considered. This paper proposes the optimal on-line real time voltage regulation methods in power distribution systems interconnected with the DSG systems. In order to deliver suitable voltage to as many customers as possible, the optimal sending voltage should be decided by the effective voltage regulation method by using artificial neural networks to consider the rapid load variation and random operation characteristics of DSG systems. The simulation results from a case study show that the proposed method can be a practical tool for the voltage regulation in distribution systems including many DSG systems.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.12 no.6
• /
• pp.2698-2706
• /
• 2011

This paper deals with the optimal operation algorithm of SVR(Step Voltage Regulator) which is located with primary feeders and proposes the optimal operation system to evaluate customer voltage. The existing algorithm of SVR adapts the constant sending voltage method, which may cause the power quality problems such as overvoltage and under voltage variations in case where the distributed generations are interconnected with the primary feeders. Therefore, this paper proposes the optimal algorithm of LDC method for SVR using least square method to obtain the optimal setting values. Also, this paper presents the optimal evaluation system based on the former algorithm. The simulation results according to the types and capacities of distributed generations shows the effectiveness.

• Journal of the military operations research society of Korea
• /
• v.3 no.1
• /
• pp.109-114
• /
• 1977

There are some factors which cause the profits from the production to be decreased or increased. They are, for example, the rise in efficiency of production facilities resulting from the development of the scientific technique, the changes of purchase price of those, and the drop in efficiency of those owing to there long-term operation. In this connection, an manager can get the highest profit by deciding the proper time of new facilities replacement for those in operation or in being planned, which leads to good management planning of his manufactaring business for a given period or a long time. Main purpose of this is the study of how we decide the optimal time or facilities replacement in order to maximize the total profits for a given period by considering them as continous function as to the time in the case where a machineng is set. The results are following: 1. The definition of profit function is in duced in consideration of the breakdowns caused from continous operation of the machinery. 2. The necessary conditions are obtained for the optimal time of replacement and find out the methods of its solution. 3. Comparing between the 'Short cut' method and method in this paper, we obtained that our method is more realistic.