• Bulletin of the Korea Photovoltaic Society
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• v.4 no.2
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• pp.45-53
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• 2018

Natural gas demand for power generation continued to increase until 2013 due to the expansion of large-scale LNG power plants after the black-out of 2011. However, natural gas demand for power generation has decreased sharply due to the increase of nuclear power and coal power generation. But demand for power generation has increased again as energy policies have changed, such as reducing nuclear power and coal power plants, and abnormal high temperatures and cold waves have occurred. If the gas pipeline pressure can be properly maintained by predicting these fluctuations, it can contribute to enhancement of operation efficiency by minimizing the operation time of facilities required for production and supply. In this study, we have developed a regression model with daily power demand and base power generation capacity as explanatory variables considering characteristics by day of week. The model was constructed using data from January 2013 to December 2016, and it was confirmed that the error rate was 4.12% and the error rate in the 90th percentile was below 8.85%.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.41 no.5
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• pp.44-49
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• 2009

Old newspaper was deinked using commercial cellulolytic enzymes and a surfactant complex at low alkalinity. The properties of the deinked pulp(DIP) were evaluated and the suspended solids content, cationic demand, turbidity, and chemical oxygen demand(COD) of the process water were measured. The results can summarized as follows, 1. The brightness and yield of the DIP were improved using enzymatic surfactant complex deinking. 2. The amount of foaming during deinking with the enzyme surfactant complex was higher than that with synthetic surfactant deinking. However, it was not sufficient to cause process problem. 3. The pH and turbidity of the white water from deinking with the enzyme surfactant complex were similar to those of the white water from surfactant deinking. 4. The suspended solids content, cationic demand, and COD of the white water from deinking with the enzyme surfactant complex were improved compared to those of the white water from surfactant deinking.

• Journal of Electrical Engineering and Technology
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• v.12 no.6
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• pp.2157-2165
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• 2017

This study deals with the design of the mechanism in which demand response (DR) resources are traded in the power generation market. In general, a DR aggregator (DRA), which extends DR resources and provides technical support, is central to this mechanism. In this study, power users, called DR customer (DRC), participate in load reduction and are also modeled to participate directly in DR-related bidding. The DRA provides incentives to the DRC, indirectly impacting the market, and the DRC use the bid parameters strategically. We present the conditions for finding Nash Equilibrium (NE) in game problems of various participants including market operators, and analyze the characteristics of DRA and DRC related models. It also analyzes the impact of the participants on the market according to various types of competition and coalitions between DRA and DRC.

• Journal of Families and Better Life
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• v.27 no.2
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• pp.45-61
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• 2009

The purpose of this study was to develop an understanding of older consumers' lifestyle, and to provide the basic information for developing silver commodities and, in turn, to stimulate the silver industry which has received attention as a next-generation industry. The study divided elderly consumers into four lifestyle categories and analyzed the difference in demographic characteristics among these categories as well as differences in demand for silver products. Data were collected with questionnaire and analyzed with frequency analysis, factor analysis, K-means cluster analysis, one-way ANOVA, and a $x^2$ test using SPSS 15.0. Four different lifestyles categories were identified among elderly consumers : conservative and stability oriented (22 persons, 33.3% of the sample), progressive and relation oriented (22 persons, 15.0%), reality adapted (52 persons, 35.4%), and traditional (24 persons, 16.4%). The demand for silver products demands was significantly different among elderly consumers in the four different lifestyle groups.

• Journal of the Korean housing association
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• v.6 no.2
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• pp.33-42
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• 1995

At the moment the housing demand needs estimated at the level of provinces and big cities. But at the level of small cities and smaller administrative unit like Goon, it is not, for lack of appropriate estimating method. Therefore it is very much required to develope appropriate estimating method at such levels. This study is an attempt to apply to some local areas the estimating method developed by Professor Miyqke of Japan as is suggested in his article. "How to Estimate the Housing Demand in Relation with the Different of Poulation Structure." The result shows that the applied local areas showed repective characteristics distinguished from one another in the pattern of housing demand, to prove the approprateness of the method when applied to the areas at the level of small cities and Goons.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.721-729
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• 2009

Recently, there has been growing necessity to estimate the future travel demand of high speed train because the circumstance of high speed train service is rapidly changing with the launching of 2011 second stage of Gyeongbu high speed railway(Dongdaegu-Busan) and the completion of 2014 first stage of Honam high speed railway(Yongsan-Gwangju), etc. This study was designed to estimate future travel demand by analyzing the transport performance and train service characteristics of Gyeongbu and Honam line. This study presents the maximum load section and the changed future travel demand, which will be applied to establish a train operation plan.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.8 no.4
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• pp.1-7
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• 2012

In this study, computer simulation for demand control strategies to save the electric energy and power price in the building central cooling system is done. The demand control and outdoor reset control algorithms are applied by consideration the electric energy and power price according to the energy consumption characteristics. The suggested control methods show better responses in the power price and energy consumption in comparison with the conventional one.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.12
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• pp.568-574
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• 2001

The variations of real time electric power price in competitive electricity markets have influence on electric power demands of the consumers. The effects of the consumers for electric power price can be expressed the price elasticity coefficient of the power demand as a measurement. Residential, commercial, and industrial consumers with different characteristics cause the different price elasticity of the power demand due to changing the pattern of consumption. It is necessary that the effects of electric power demands as a function of elasticity coefficient for each loads should be analyzed in Korea which is processing deregulated electric market. Therefore, this paper calculate the elasticity coefficient of each loads and analysis the effects of electric power demands as a function of elasticity coefficient of inflexible and flexible consumers in competitive electricity market.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.369-374
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• 2011

Generally the neural network and the Fuzzy compensative algorithms are applied to forecast the time series for power demand with the characteristics of a nonlinear dynamic system, but, relatively, they have a few prediction errors. They also make long term forecasts difficult because of sensitivity to the initial conditions. In this paper, we evaluate the chaotic characteristic of electrical power demand with qualitative and quantitative analysis methods and perform a forecast simulation of electrical power demand in regular sequence, attractor reconstruction and a time series forecast for multi dimension using Lyapunov Exponent (L.E.) quantitatively. We compare simulated results with previous methods and verify that the present method is more practical and effective than the previous methods. We also obtain the hourly predictability of time series for power demand using the L.E. and evaluate its accuracy.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.905-907
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• 1993

Demand for electricity is increasing annually. Especially, the daytime demand grawth shows higher than any other time period. So the big difference between maximum and minimum electrical demand becomes another important problem to be solved. The Battery Energy Storage System is chosen as one of the solutions among the sevral methods. The purpose of utilization of Battery Energy Storage System is to improve the daily load factor. Also, Battery Energy Storage System may be used for the load levelling or the load shifting as well as the spinning reserve. Up to now, only the pumped hydro power plant system has been operated on the commercial basis, but this system has so many constraints such as site, environmental effects, construction period, ect. Being considered current electrical power situation the development of electric storage system is in need latly. Among the various electric storage systems, Battery Energy System is chosen with the top priority because it has sevral merits to cover such as the short construction period, the demand site installation, and the food environmental characteristics.