• Information Systems Review
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• v.16 no.1
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• pp.37-50
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• 2014

Conventional case-based reasoning (CBR) does not perform efficiently for high volume dataset because of case-retrieval time. In order to overcome this problem, some previous researches suggest clustering a case-base into several small groups, and retrieve neighbors within a corresponding group to a target case. However, this approach generally produces less accurate predictive performances than the conventional CBR. This paper suggests a new hybrid case-based reasoning method which dynamically composing a searching pool for each target case. This method is applied to diagnose for the heart disease dataset. The results show that the suggested hybrid method produces statistically the same level of predictive performances with using significantly less computational cost than the CBR method and also outperforms the basic clustering-CBR (C-CBR) method.

• Journal of Energy Engineering
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• v.15 no.1 s.45
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• pp.14-22
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• 2006

Various pros and cons are raised as to the nuclear and renewable power portions. In order to generate scientific, objective, and comparative data, this study reviewed energy policies of some countries and derived 34 possible energy mix scenarios depending on the nuclear portion, the renewable portion and the make-up power sources. For each scenario, the unit electricity cost was calculated using the BLMP (Base Load Marginal Price) and SMP (System Marginal Price) methodology, which is currently adopted in Korean electricity market. The unit electricity cost for the current energy mix was 22.18 Won/kWh and those fir other scenarios spreaded from 19.74 to 164.07 Won/kWh excluding the transmission costs and profits of the electric utility companies. Generally, the increased nuclear power portion leads reduction in the unit electricity cost while the trend is reversed in the renewable power portion. Notable observation is that when the renewable power portion exceeds 20%, as the scenario cannot enjoy the benefit of cheap base load, the unit electricity cost at low demand time zone is increased.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.58 no.6
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• pp.1087-1092
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• 2009

This paper presents a method for improvement of capacity payment in CBP(cost based pool) market. Capacity payments have been used as common mechanisms in various pools for compensating generators recognized to serve a for reliability purpose. Ideal pricing for capacity reserves by definition achieves a balance between economic efficiency and investment incentives. That is, prices must be kept close to costs, but not so low as to discourage investment. However, the price set is not easy. This paper concludes with market design recommendations that apply fuzzy theory for improvement of capacity payment. Following this model, market participants decided on their own based on their forecast to the market demand and the payment for it.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.1
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• pp.20-24
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• 2008

A bid-based pool(BBP) model is representative of energy market structure in a number of restructured electricity markets. Supply function equilibrium(SFE) models of interaction better match what is explicitly required in the bid formats of typical BBP markets. Many of the results in the SFE literature involve restrictive parametrization of the bid cost functions. In the SFE models, two parameters, intercept and slope, are available for strategic bidding. This paper addresses the realistic competition format that players can choose both parameters arbitrarily. In a fixed demand function, equilibrium conditions for generation company's profit maximization have a degree of freedom, which induces multi-equilibrium. So it is hard to choose a convergent equilibrium. However, consideration of stochastic demand function makes the equilibrium conditions independent each other based on the amount of variance of stochastic demand function. This variance provides the bidding players with incentives to change the slope parameter from an equilibrium for a fixed demand function until the slope parameter equilibrium.

• Journal of Information Technology Applications and Management
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• v.14 no.4
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• pp.31-41
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• 2007

In order to keep global competitiveness, most of small and medium size manufacturing companies require to equip a product information management system which collects and analyzes the data generated at the manufacturing lines and then provides information for manager or worker to make a decision. However, these companies have a cost problem for adopting the enterprise resource planning system mostly used in large companies. To overcome this problem, we suggest an IOCP-based server for the product information management system suitable for small and medium size manufacturing companies. The basic concept of suggested server is that it is possible to process concurrently the connection requests coming from data collector and client by using the facility of asynchronous notification of OS and protect a server against overload by using the thread pool.

• KIEE International Transactions on Power Engineering
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• v.5A no.2
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• pp.199-203
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• 2005

This paper proposes the level of price cap in the TWBP(Two- Way Bidding Pool) market in Korea for which the draft of market design has been prepared by KPX. Max - GMCP(Maximum Generation Market Clearing Price) and APC(Administered Price Cap) would be separately applied as individual price caps for a normal period and a Price Capping period in TWBP. The level of price cap is determined for inducing optimal investment in the Korean Electricity Market considering the 'electricity resource baseline plan' published by the Korean government in 2002 for maintaining government-leading resource planning in Korea. In this regard, Max - GMCP is calculated from the equilibrium condition of investment based on reliability standard and fixed cost of the peaking plant. For verifying the propriety of the proposed price cap, this paper compares the proposed value with the estimated VoLL(Value of Lost Load) based on Korea's GDP(Gross Domestic Product).

• Korean Journal of Construction Engineering and Management
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• v.16 no.4
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• pp.139-145
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• 2015

Modular construction is combined with manufacturing production process and conventional construction industry technique. Considering characteristic of modular construction production process, manufacturing facilities require indirect costs for utilities, equipment, and overall maintenance, which can affect modular units pricing. However, current modular construction cost classification is inadvertent to reflect the manufacturing overhead costs, because it is generally added as a percentage to sum of labor, material and equipment as it called in single cost pool used. This process is easy to estimate the total construction cost at the project starting points, but it brings on misunderstanding of project profit estimations by "cross subsidization phenomenon". To prevent this situation, in this research aims to provide modular construction overhead cost handling process at the detailed indirect cost calculation for manufacturing stage using Activity-Based Costing as one of the powerful method for overhead costs estimation and allocation. Using this research results, modular construction cost estimators have more detailed cost information of modular units and prevent to misallocate indirect costs. Also, it can be utilized to aid the understanding of the company's profit structure.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1344-1346
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• 1999

This paper presents a game theoretic approach for power transactions analysis in a competitive market. The considered competitive power market is regarded as PoolCO model, and the participating players are restricted by only two generating entities for simplicity in this paper. The analysis is performed on the basis of marginal cost based relations of bidding price and bidding generations. That is, we assume that the bidding price of each player is determined by the marginal cost when the bidding generation is pre-determined. This paper models the power transaction as a two player game and analyzes by applying the Nash eauilibrium idea. The generalized game model for power transactions covering constant-sum(especially zero-sum), and nonconstant-sum game is developed in this paper. Also, the analysis for each game model are Performed in the case studies. Here, we have defined the payoff of each player as the weighted sum of both player's profits.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.3
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• pp.536-542
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• 2010

This paper presents an unique approach to scheme a demand response (DR) program in the electricity market from a customer-oriented perspective, which is based on the analytic hierarchy process (AHP). The proposed program has the objective to maintain the system reliability at the emergency period, and it is designed as an incentive-based program (IBP) considering Korea power systems with the cost-based generation pool (CBP). The DR program using AHP could represent the mutual importance degrees of load curtailment criteria from the viewpoint of different load-holders, thus customers' participation in this program is determined by the incentive payments corresponding the specific load curtailment conditions. A test system for the case study is used to demonstrate the usefulness and applicability of the proposed approach, and the load profiles with the proposed DR program and the required incentive payments are obtained. The results show not only the enhancement of system reliability but also the economic benefit within Pareto-improvement.

• Proceedings of the KIEE Conference
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• 2008.11a
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• pp.194-196
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• 2008

우리나라 전력시장은 2001년 4월부터 구조개편 초기모델로 원가반영발전시장(Cost Based Pool)으로 새로운 경쟁적 시장환경이 도입되면서 지역간 연계를 위한 송전망의 확충은 개별 시장참여자뿐만 아니라 다양한 이익주체들에게 경제적 편익에 큰 영향을 미칠 수 있다. 따라서 국내 전력시장 환경에 적합한 송전망 투자의 경제성 평가 절차와 방법을 개발하고 전산모형을 활용하여 실제 계통계획(안)에 적용하여 시장참여자별 경제적 효과를 평가한다.