• Proceedings of the Korea Water Resources Association Conference
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• 2008.05a
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• pp.500-504
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• 2008

The objective of this paper is to evaluate the feasibility of using an optimization model as a effective way to search conjunctive operation scheme to meet two conditions; one is to minimize the electric cost for pumping and another is to meet the water demand for satisfying customers. The feasibility is confirmed as comparing the best combinations of pumps between multi-regional water supply networks from multiple sources which are obtained through an optimization modeling and EPAnet modeling. KModsim model, a network optimization model, was used to determine conjunctive operation scheme in the pipe system. KModsim, based on Lagrangian Relaxation algorithm, is useful for modeling network system and obtaining simultaneously pump combination and water allocation with given input option such as energy unit cost supplying from a source into a consumer, operating pumping combination. This study develops the procedure of determining optimal conjunctive operation scheme with using KModsim model. As a study region, the water supplying systems of the Geojae-city in the Geongsang Namdo Province was selected and investigated. The EPAnet hydraulic simulation result(Ryu et al, 2007, KSWW) gave input data for optimization model; energy unit price(won/$m^3$), water service available area etc.. It was assured that the combination of pump operation through optimum conjunctive operation is to be optimum scheme to obtain the best economic water allocation with comparison to the hydraulic simulation result such as electric cost and pump combination cases. The results obtained through the study are as follows. First, It was found that a well-allocated water supply scheme, the best combination of pump operation through optimum joint operation, promises to save the electric cost and satisfy all operational goals such as stability and revenues during the period. Second, an application of KModSim, a network model, gave the amount of water allocation from each source to a consumer with consideration of economic supply. Finally, in a service area available to supply through conjunctive operation of existing inter-regional water supply networks within short distance, a conjunctive operation is useful for determining each transmission pipeline's service area and maximizing the effectiveness of optimizations in pumping operation time.

• Journal of Computational Design and Engineering
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• v.1 no.4
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• pp.233-242
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• 2014

A magnetically levitated vehicle (Maglev) system is under commercialization as a new transportation system in Korea. The Maglev is operated by an unmanned automatic control system. Therefore, the plan of train operation should be carefully established and validated in advance. In general, when making a train operation plan, statistically predicted traffic data is used. However, a traffic wave often occurs in real train service, and demand-driven simulation technology is required to review a train operation plan and service quality considering traffic waves. We propose a method and model to simulate Maglev operation considering continuous demand changes. For this purpose, we employed a discrete event model that is suitable for modeling the behavior of railway passenger transportation. We modeled the system hierarchically using discrete event system specification (DEVS) formalism. In addition, through implementation and an experiment using the DEVSim++ simulation environment, we tested the feasibility of the proposed model. Our experimental results also verified that our demand-driven simulation technology can be used for a priori review of train operation plans and strategies.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.05a
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• pp.341-343
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• 2012

This study introduces a method for computation of process and operation gap in the specific construction operation(i.e., RC frame construction applying a block-grouping scheme) using CYCLONE-based simulation modeling and analysis technique. Since uncertainty of construction environment exists, a thoughtful production planning is required to effectively deal with a risk resulting in schedule delay in advance. This study presents the concepts of a time delay occurred in a process level and operation level in a operation model, and a method of measuring gap-times in each level while the simulation progresses. It helps a site manager to decide how many segmentation in a construction block is suitable for eliminating unproductive time-delays under the constrained resources (e.g., laborer, equipment). A case study presents a network model representing a three segmented RC frame work, and result obtained from the simulation experiment.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.486-492
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• 1999

One of the purpose of the reservoir operation is minimizing theinnudation area in the downstream reaches during flood period.l To execute the gate operation properly , it requires lots of real-time data such as rainfall, reservoir level, and water level in the downstrea. Gate operation model was developed with the flood discharge obtained from real-time flood forecasting model and the criterion prepared from the past history of gate operation. Water level in the downstream would be increased by the releasing discharge from the spillway and the area of paddy land flooded in a certain detph and time would be estimated usnig GIS map. Gate operation model was applied to the Yedang reservoir, and the flooded area, depth and time in the paddy land was estimaged.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.119-124
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• 2005

Decision of operation performance mode to minimize the energy consumption of urban rail vehicle. This paper analyses how much acceleration and deceleration of urban rail vehicle should be applied andhow to choose an operation mode to minimize energy consumption when train runs between station within the fixed operation time. The decided operation pattern satisfying the minimum energy consumption becomes a target trajectory and a basis for the controller design criteria. To make this goal it grasps the characteristics of urban rail vehicle, realize operation energy model of urban rail vehicle and verify the accuracy of embodied model the Matlab simulation with the same operation result of real route. It searches for operation pattern to minimize operation energy by changing the acceleration and deceleration on the imaginative route and proposes operation pattern minimizing energy consumption by applying real operation data between Dolgogee-Sukgye section of Seoul Metropolitan Subway Line 6.

• Journal of Engineering Education Research
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• v.22 no.4
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• pp.71-77
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• 2019

Capstone design is a very important college course that enhances students' creativity and skills. However, in most universities, the operation of capstone design is operated by the experience and intuition of the advisor, and it is somewhat lacking in the generation of useful results such as patent rights and technology start-up from the capstone design result. In this study, we proposed a performance - based capstone design operation model through patent linkage so that the capstone design class can create creative and useful results. The proposed operating model includes support for research on prior art of patent information utilization, patent right of idea, and technology commercialization. The proposed operating model was directly applied to the capstone design class in the university, and it was confirmed that useful results such as expansion of the scope of the research achievement and technology start - up were created compared to the existing operation model.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.5
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• pp.174-182
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• 2004

Consideration for parallel operation in a high power system has been increased due to the advantages of parallel operation like as high productivity, simplicity of design, and redundancy of power. Based on the small signal model of DC-DC Converter, the simple and exact power stage model of parallel operation system is derived and the parallel operation system using current balance method for the uniform current distribution among the parallel operation system is proposed. Using Simulation programs, which consists of nonidentical Converter modules and changes the position of master and slave automatically, the current distribution error is kept within the limit in the parallel operation system. To verify the high performance of the proposed Converter system for parallel operation, the parallel operation test, which has 2 Converter modules of 1 kW, is accomplished. Also, the simulation result is good agreement with the experiment result in the transient and starting characteristics.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.6
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• pp.969-978
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• 2016

Around the world are increasing the demand for ESS. Currently, the domestic is expected to benefit by operating ESS. In the domestic, it is expected to benefit from operations of the installed ESS because of the introduction of ESS less capacity. However ESS capacity to the maximum profit occurs is unknown. ESS is different from the charge-discharge characteristics and the reserve to replace, depending on the application. Therefore, it should be established in accordance with the ESS optimal capacity according to the purpose used because it can maximize the quality and efficiency of the electric energy. To the ESS optimal capacity estimation by the purpose used, It should compare the investment cost caused by ESS facility installation and operation cost caused by operating ESS. In this paper, the operation mathematical model for estimating marginal operation costs established. In operation mathematical model, operating cost is considered fuel cost and no-load cost start-up cost. Because no-load cost and start-up cost are not related to cost and power plant output, there are expressed an integer variable costs as a step function.

• Information Systems Review
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• v.4 no.2
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• pp.293-307
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• 2002

In this study, industry-specific application systems operation cost estmation models are suggested. We reviewed operation cost models of previous researches, and developed a strong need for industry-specific operation outsourcing cost models. Security industry operation cost model and medical care industry outsourcing cost model are proposed, and tested with empirical data. We showed the validity of industry-specific application systems outsourcing cost models. Future research will be needed to develop outsourcing cost models for other industries and to refine cost models developed in this study.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.1
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• pp.174-183
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• 2005

A train driving requires to n the fixed distance within given time, and it is desirable to consume low energy if necessary. Reducing energy consumption depends on the train operation modes by either manual or automatic operation. In this article, an operation to reduce energy consumption by changing modes of train operation by a driver without changing the train operation requirement is investigated. The powering model, braking model and consumed energy calculation model are developed, then simulated by using a Matlab software. The accuracy of the train dynamic model established by the simulations is verified by comparing with the real experimental data. Several simulations by various operations in the real track are executed, then the desirable pattern of train driving is found.