• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.9
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• pp.142-149
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• 2010

Interest in energy efficiency and savings have been rising internationally. For this reason, the domestic housing construction in the area of power equipment is being actively studied. Currently approximately 400,000 per year of domestic housing is being built. Applies to housing construction during the current transformer capacity low utilization and load factor has been applied has been designed. In other words, excessively high reserve capacity has been applied. According to this problem, initial facility costs and power losses will cause because transformer low utilization be appropriated. Thus, the energy efficiency drops. In this paper, analysis of past utilization of the housing transformer, and applying an appropriate demand factor has been analyzing the energy loss reduction. this analysis of current domestic conditions for the proper housing transformer scheme is to calculate the capacity.

• KIEE International Transactions on Power Engineering
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• v.5A no.3
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• pp.252-259
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• 2005

Various problems such as increase of power loss and voltage instability may often occur in the case of low load power factor. The demand of reactive power increases continuously with the growth of active power and restructuring of electric power companies makes the comprehensive management of reactive power a troublesome problem, so that the systematic control of load power factor is required. In this paper, the load power factor sensitivity of generation cost is derived and it is used for effectively determining the locations of reactive power compensation devices and for enhancing the load power factor appropriately. In addition, voltage variation penalty cost is introduced and integrated costs including voltage variation penalty cost are used for determining the value of load power factor from the point of view of economic investment and voltage regulation. It is shown through application to a large-scale power system that the load power factor can be enhanced effectively using the load power factor sensitivity and the integrated cost.

• Journal of The Korean Association For Science Education
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• v.12 no.3
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• pp.49-59
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• 1992

New-Piagetian theory has proposed that mental capacity and mental demand do a critical role in human cognitive processes. In this study, the students' mental capacity and the mental demand of the given problems were examined. The principal findings of the study are as follows; (1) There was no significant difference among achievement scores of subjects (3rd grade students of middle school, 2nd grade students of high school, 3rd grade students of high school) in the items of balance that needed specific content knowledge. But, in the Newton's 2nd law items that needed specific content knowledge, there was significant difference be ween3rd grade students of middle school and high school students(2nd, 3rd). According to increase of mental demand, middle school students' achievement score appeared to decrease linearly. However high school students' achievement score didn't change untill they faced the items of critical mental demand. When mental demand was beyond critical mental demand,their score was decreased rapidly. (2) According to hierchical analysis of items, the more mental demand an item needed, the higher or at least the same hierachical item was. These results showed that mental demand was the main factor which decided diffculties of problem solving (3) It was possible for students to solve the newton's 2nd law item that had one or two more mental demand relative to balance beam item. Although the item needed the same mental demand.students recognized that the Newton's 2nd law items were easier than the balance beam items.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2004.04a
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• pp.417-422
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• 2004

It is the challenging task to predict seismic demand for structural design. In current seismic design provisions such as UBC, NEHRP, ATC 3-06, the seismic demand is calculated using the response spectrum with response modification factor (R). This paper investigates variability of seismic demand according to selecting the earthquake ground motion groups. Different Earthquake sets used by Miranda, Riddell and Seed selected were used in this study. Earthquake sets selected by authors include 62 sets of near field ground motion and 19 sets one pulse ground motion. Linear Elastic Response Spectrum (LERS), the variation of performance points of calculated by Capacity Spectrum Method (CSM) were considered with respect to the different sets of earthquake ground motions.

• Journal of the Korean Operations Research and Management Science Society
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• v.34 no.4
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• pp.91-112
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• 2009

The bullwhip effect means the phenomenon of increasing demand variation as moving UP to the upstream in the supply chain. Therefore, it is recognized that the bullwhip effect is problematic for effective supply chain operations. In this paper, we exactly quantifies the bullwhip effect for the case of stochastic lead time and seasonal demand in two-echelon supply chain where retailer employs a base-stock policy considering SARMA demand processes and stochastic lead time. We also investigate the behavior of the proposed measurement for the bullwhip effect with autoregressive and moving average coefficient, stochastic lead time, and seasonal factor.

• 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 Korean Society of Water and Wastewater
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• v.20 no.4
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• pp.527-534
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• 2006

Demand side management(DSM) is the newly raised issues in the water resources management in recent. Many of the policy tools among demand management, the most important measures might be a pricing system. Furthermore, the responses of consumers on the price for water consumption level is the key factor for policy making. Here, we estimated panel data for 167 regions and over 7 years periods in Korea. Compare to other previous studies the price elasticities were somewhat low. The estimated price elasticity was -0.05. It was because the short term estimated period may derive lower elasticities. However, it might be a recent trend after the continuous increment of water pricing and consumers not willing to decrease their residential water consumption with increasing water pricing. According to this results, water saving effect might be much smaller than we expect with pricing policy. However, It does not imply there is no price effects on water consumption and it's still meaningful as a tool of water management.

• Journal of The Korea Institute of Healthcare Architecture
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• v.17 no.3
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• pp.27-33
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• 2011

The purpose of this study is to propose reasonable standards related to securing the number of parking lots of university hospital in Korea. High proportion of visitors use their cars in order to receive consultation and treatment from doctors and feel the shortage of parking capacity of hospital, resulting to the low satisfaction level in using hospital. Of course, every hospital meets the parking regulation of the government. Therefore it is necessary to consider another parking demand factors besides the parking regulation of the government in order to secure proper number of parking lots in hospital. This study proposes number of hospital beds, vicinity of public transportation, number of doctors and staffs of hospital, and peak time parking demand as the parking demand factors.

• Proceedings of the KIEE Conference
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• 1999.11b
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• pp.169-171
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• 1999

This paper presents a new demand control technique using fuzzy logic. Generally, predictive demand control method often brings about a large number of control actions and undesirable alarm during the beginning stage of the demand period. To solve this problem, a fuzzy predictive algorithm is proposed. The main idea of the method is the determination of sensitivity factor by using fuzzy logic. The performance of the proposed algorithm is tested through a case study.

• 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.