• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.10
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• pp.28-37
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• 2011

Though Korea has introduced CBP(Cost Based pool) power trading system since 2001, long-term Generation system planning has been executed by government for Cost minimization every 2 years. Until currently the model which is used for Generation system planning and best-mix only considers cost minimization and total yearly or quarterly electricity demand every year. In a view point of one day power supply operation, technical characteristics, like the ramp up/down rate of total generation system, minimum up/down time and GFRQ(Governor Free Response Quantity), are very important. this paper analyzes Optimal Fuel-Mix for 2022 Korea generation system satisfying these constraints of each fuel type and considering pump storage plants, construction cost and $CO_2$ emission charge Using MILP(Mixed Integer Linear Programming) method. Also the sensitivity analysis which follows in future power industry environmental change accomplished.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.6
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• pp.783-790
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• 2012

Electric Vehicles(EVs) and Plug-in Hybrid Electric Vehicles(PHEVs) which have the grid connection capability, represent an important power system issue of charging demands. Analyzing impacts EVs charging demands of the power system such as increased peak demands, developed by means of modeling a stochastic distribution of charging and a demand dispatch calculation. Optimization processes proposed to determine optimal demand distribution portions so that charging costs and demand can possibly be managed. In order to solve the problems due to increasing charging demand at the peak time, alternative electricity rate such as Time-of-Use(TOU) rate has been in effect since last year. The TOU rate would in practice change the tendencies of charging time at the peak time. Nevertheless, since it focus only minimizing costs of charging from owners of the EVs, loads would be concentrated at times which have a lowest charging rate and would form a new peak load. The purpose of this paper is that to suggest a scenario of load leveling for a power system operator side. In case study results, the vehicles as regular load with time constraints, battery charging patterns and changed daily demand in the charging areas are investigated and optimization results are analyzed regarding cost and operation aspects by determining optimal demand distribution portions.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.4
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• pp.95-102
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• 2010

As the electric power industry is evolving into competitive market scheme, a new paradigm is required for the operation of market. Traditional dispatch algorithm was built based on the optimization model with an objective function and multiple constraints. Commercial market simulator followed the concept of the microeconomic model used in the dispatch algorithm, which is called as analytic method. On analytic method it is prerequisite to procure the exact data for the simulation. It is not easy anymore for each market participant to access to other participants' financial information while it used to be easy for monopoly decision maker to know all the information needed for the optimal operation. Considering the changing situation, it is required to introduce a new method for estimating the market price. This paper proposes an empirical method based on stochastic processes expected to build a capacity planning and long term contracts.

• The Korean Journal of Emergency Medical Services
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• v.27 no.2
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• pp.91-111
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• 2023

Purpose: This study aims to compare 119 emergency medical services (EMS) in South Korea and Japan to provide essential data for EMS improvement in South Korea. Methods: Recent data and regulations on firefighting and EMS in South Korea and Japan were analyzed and compared. Results: South Korea follows a centralized approach to EMS, whereas Japan operates with autonomous bodies that establish their own criteria. Japan considers more regional variables than South Korea. In South Korea, there are shortages in fire station deployment among the 119 emergency medical resources in certain regions, leading to significant regional disparities. South Korea has a larger population served by its 119 emergency medical resources with a higher workload and dispatch numbers than Japan. The percentage of non-transported patients among the total number of dispatches was higher in South Korea. Conclusion: Increasing the number of medical professionals and ambulances per population to the level of Japan to reflect local conditions and include various underlying variables such as daytime population, aging, and emergency dispatch conditions in the deployment of 119 emergency resources, and to reduce the deployment gap between regions, will contribute to improving the performance of the South Korea EMS system.

• IE interfaces
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• v.14 no.3
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• pp.247-254
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• 2001

As current postal automation is limited to dispatch and arrival sorting, delivery sequence sorting is performed manually by each postman. It not only acts as a bottleneck process in the overall mailing process but is expensive operation. To cope with this problem effectively, delivery sequence sorting automation is required. The important components of delivery sequence sorting automation system are sequence sorter and Hangul OCR which function is to extract the address of delivery point. DSI database will be interfaced to both Hangul OCR and sequence sorter for finding the accurate delivery sequence number and stacker number. The objectives of this research are to develop DSI(Delivery Sequence Information) database prototype and client application for managing information effectively. For database requirements collection and analysis, we draw all possible sorting plans, and apply the AHP(Analytic Hierarchy Process) method to determine the optimal one. And then, we design DSI database schema based on the optimal one and implement it using Oracle RDBMS. In addition, as address information in DIS database consist of hierarchical structure which has its correspondence sequence number, so it is important to reorganize sequence information accurately when address information is inserted, deleted or updated. To increase delivery accuracy, we reflect this point in writing application.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.5
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• pp.272-281
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• 1988

The problem of optimal transmission system planning is to find the most economical locations and time of transmission line construction under the various constraints such as available rights-of-way, finances, the technical characteristics of power system, and the reliability criterion of power supply, and so on. In this paper the constraint of right-of-way is represented as a finite set of available rights-of-way. And the constructed for a unit period. The electrical constraints are represented in terms of line overload and steady state stability margin. And the reliability criterion is dealt with the suppression of failure cost and with single-contingency analysis. In general, the transmission planning problem requires integer solutions and its objective function is nonlinear. In this paper the objective function is defined as a sum of the present values of construction cost and the minimum operating cost of power system. The latter is represented as a sum of generation cost and failure cost considering the change of yearly load, economic dispatch, and the line contingency. For the calculation of operating cost linear programming is adopted on the base of DC load flow calculation, and for the optimization of main objective function nonlinear Branch-and-Bound algorithm is used. Finally, for improving the efficiency of B & B algorithm a new sensitivity analysis algorithm is proposed.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.51 no.8
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• pp.379-384
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• 2002

In the competitive electricity market, various pricing methods are developed and practiced in many countries. Among these pricing methods, marginal loss factor(MLF) can be applied to reflect the marginal cost of network losses. For the calculation of MLF, power flow method has been used to calculate system loss deviation. However, this power flow method shows some shortcomings such as necessity of regional reference node, and absence of an ability to consider network constraints like line congestion, voltage limit, and generation output limit. The former defect might affects adversely to the equity of market participants and the latter might generate an inappropriate price signals to customers and generators. To overcome these defects, the utilization of optimal power flow(OPF) is suggested to get the system loss deviation in this paper. 30-bus system is used for the case study to compare the MLF results by the power flow and the OPF method for 24-hour dispatching and pricing, Generator payment and customer charge are compared with these two methods also. The results show that MLF by OPF reflects the power system condition more faithfully than that of by the conventional power flow method

• Journal of Electrical Engineering and Technology
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• v.4 no.1
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• pp.1-12
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• 2009

In recent years, integration of new distributed generation (DG) technology in distribution networks has become one of the major management concerns for professional engineers. This paper presents a dynamic methodology of optimal allocation and sizing of DG units for a given practical distribution network, so that the cost of active power can be minimized. The approach proposed is based on a combined Genetic/Fuzzy Rules. The genetic algorithm generates and optimizes combinations of distributed power generation for integration into the network in order to minimize power losses, and in second step simple fuzzy rules designs based upon practical expertise rules to control the reactive power of a multi dynamic shunt FACTS Compensator (SVC, STATCOM) in order to improve the system loadability. This proposed approach is implemented with the Matlab program and is applied to small case studies, IEEE 25-Bus and IEEE 30-Bus. The results obtained confirm the effectiveness in sizing and integration of an assigned number of DG units.

• 전기의세계
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• v.21 no.2
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• pp.34-40
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• 1972

This paper describes the problem of the shortange-economic-scheduling for unit commitment and load dispatching in thermal power system. For economic operation of thermal system, the optimum time of startup and shoutdown of the generating unit must be determined so as to minimize the sum of generating and starting fuel cost over a given period. The above problems are analyzed for the purpose of the application of Dynamic Programing Method. Also the technique of Dynamic Programming is applied to the problems. For the illustative purpose, a case study was made on a model system composed of eight units and the computing time was about 190 seconds by IBM 360-40 system. Therefore, one can utilize this suggested method on any of the practical power systems.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.49-51
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• 2000

ln this paper, a method by which penalty factors of all generators including slack bus can be directly derived is presented. With a simple re-assignment of angle reference bus to a bus where no generation exists, penalty factors for slack bus is obtained without any physical assumption. While previous Jacobian-based techniques for generator penalty factor calculation have been derived with basis upon reference bus, proposed method are not dependent on reference bus and calculated penalty factors can be substituted directly into the general ELD equation to compute the economic dispatch. Equations for system loss sensitivity, penalty factors and optimal generation allocation are solved simultaneously in normal power flow computation.