• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.1
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• pp.1-8
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• 1992

Hopfield neural network has been applied to the problem of economic load dispatch(ELD) of electric power. The optimum values of neuron potentials are represented in terms of large numbers. The differential synchronous transition mode is used in this simulation. Through case studies, we have shown the possibility of the application of neural network to ELD. In case of including the transmission losses, the proposed method has an advantage that the problem can be solved simply with one neural network, without calculating incremental fuel costs and incremental losses required by traditional method.

• Proceedings of the Korean Geotechical Society Conference
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• 2000.03a
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• pp.85-106
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• 2000

The load distribution and deformation of drilled shafts subjected to axial loads were evaluated by a load transfer approach. The emphasis was on quantifying the load transfer mechanism at the interface between the shafts and surrounding highly weathered rocks based on a numerical analysis and small-scale tension load tests performed on nine instrumented piles. An analytical method that takes into account the soil coupling effect was developed using a modified Mindlin's point load solution. Based on the analysis, a single-modified hyperbolic model is proposed for the shear transfer function of drilled shafts in highly weathered rocks. Through comparisons with field case studies, it is found that the prediction by the present approach is in good agreement with the general trend observed by in-situ measurements.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.1
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• pp.106-114
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• 2001

In this study, a shape optimization of stiffener was conducted to increase buckling load or failure load in each case with a different design value and a different objective function for stiffened laminated composite panel of I-type under compression loading. Regarding each of buckling load or failure load as objective function, optimum design was carried out. In respect of optimum design, the effects of relative length of web and cab of stiffener on buckling load or failure load of postbuckling were investigated.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.333-336
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• 2015

Recently, the power load is growing larger and because of the environmental limitation of generation, the expansion of generation facilities are becoming more difficult. For that reason the importance of the demand-side resources come to be higher. One method of the demand-side resource, the DLC Program, has executed, and moreover, the loads which are available to be controlled are increasing. It should be considered of some kinds of power system components such as DLCs, because the fact that using the demand resources will be an important part of the power system. This paper considers the power factor of the load-bus which is shedded in the direct load control program. and then analyze the power system using flow sensitivity and voltage sensitivity. In this paper, we assumed two scenarios through the rank of the load power factor at each bus and to compare and evaluate each case, we used Power World for the simulation.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.6
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• pp.852-856
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• 2015

Demand side management (DSM) program has been frequently used for reducing the system peak load because it gives utilities and independent system operator (ISO) a convenient way to control and change amount of electric usage of end-use customer. Planning and operating methods are needed to efficiently manage a DSM program. This paper presents a planning method for DSM program. A planning method for DSM program should include an electric load forecasting, because this is the most important factor in determining how much to reduce electric load. In this paper, load forecasting with the temperature stochastic modeling and the sensitivity to temperature of the electric load is used for improving load forecasting accuracy. The proposed planning method can also estimate the required day, hour and total capacity of DSM program using Monte-Carlo simulation. The results of case studies are presented to show the effectiveness of the proposed planning method.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.511-517
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• 2015

Determination of the required reserve capacity has an important function in operation of power system and it is calculated based on the largest loss of supply. However, conventional method cannot be applied in future power system, because potential grid-connected distributed generator and abnormal temperature cause the large load imbalance. Therefore this paper address new framework for determining the optimal required reserve capacity taking into account the real time load imbalance. At first, we introduce the way of operating reserve resources which are the secondary, tertiary, Direct Load Control (DLC) and Load shedding reserves to make up the load imbalance. Then, the formulated problem can be solved by the Probabilistic Dynamic Programming (PDP) method. In case study, we divide two cases for comparing the cost function between the conventional method and the proposed method.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1156-1163
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• 2010

The bi-directional high pile load test(BDH PLT) does not have weaknesses found in the existing bi-directional low pile load test(BDL PLT); it has strong economics, is unbound by load capacity limit and secures quality stability of working piles. In this study, Verification the field found a very high capacity level of stability and reliability of the BDH PLT, as well as outstanding field applicability. Field verifications reaffirmed the advantage of the BDH PLT device, which was capable of loading 90 MN capacities as maximum. It was also found to be durable enough to load high capacity with ease.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.6
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• pp.334-339
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• 2004

In this study, a new UC (Unit Commitment) algorithm is proposed to consider the uncertainty of a daily load profile. The proposed algorithm calculates the UC results with the lower load level than the one generated by the conventional load forecast and the more hourly reserve allocation. In case of the worse load forecast, the deviation of the conventional UC solution can be overcome with the proposed method. The proposed method is tested with sample systems, which shows that the new UC algorithm yields completely feasible solution even though the worse load forecast is applied. Also, the effects of the uncertain hourly load demand are statistically analyzed especially by the consideration of the average over generation and the average under generation. Finally, it is shown that independent power producers participating in electricity spot-markets can establish bidding strategies by means of the statistical analysis. Therefore, it is expected that the proposed method can be used as the basic guideline for establishing bidding strategies under the deregulation power pool.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.52 no.3
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• pp.179-182
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• 2003

Component-based method for load model not only should include the performances of the load components, but also should take into consideration the core losses of transformers, the line losses and the capacitor banks. Especially, capacitor bank affects the accuracy of reactive load model in load modeling. But it is difficult to identify actual reactive powers of capacitor banks in power system for load modeling. This research improves the component-based modeling method including uncertain capacitor bank. The proposed method is hybrid technique, which adds the measurement-based method to the existing component-based method for reliable information of capacitor band. The results of case studies were presented to verify the validity of the proposed method.

• KIEE International Transactions on Power Engineering
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• v.5A no.1
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• pp.16-21
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• 2005

In this study, a new Unit Commitment (UC) algorithm is proposed to consider the uncertainty of a daily load profile. The proposed algorithm calculates the UC results with a lower load level than that generated by the conventional load forecast method and the greater hourly reserve allocation. In case of the worst load forecast, the deviation of the conventional UC solution can be overcome with the proposed method. The proposed method is tested with sample systems, which indicates that the new UC algorithm yields a completely feasible solution even when the worst load forecast is applied. Also, the effects of the uncertain hourly load demand are statistically analyzed, particularly by the consideration of the average over generation and the average under generation. Finally, it is shown that independent power producers participating in electricity spot-markets can establish bidding strategies by means of the statistical analysis. Therefore, it is expected that the proposed method can be used as the basic guideline for establishing bidding strategies under the deregulation power pool.