• Architectural research
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• v.15 no.4
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• pp.201-206
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• 2013

Special attention is required for the design of windows due to their high thermal vulnerability. This paper examines the problems that might arise in the application of the u-value, by reflecting the changes in the u-value of the window, depending on the window-to-wall ratio obtained in an energy demand analysis. Research indicates that the u-value of a window increases with an increase in the difference between the u-values of the frames and the glass. Relative to the changes in the u-value of the windows, the energy demand varied from 1.3% to 9.3%. Windows with a g-value of 0.3 or 0.5 displayed a higher energy demand than windows with a g-value of 0.7. Therefore, when the difference between the performance of the glass and the frame is significant, especially when the g-value is small, a modified heat transmission coefficient should be applied to the window size during the evaluation of the building energy demand.

• Management Science and Financial Engineering
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• v.11 no.3
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• pp.125-136
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• 2005

As the importance of time-based competition is increasing, information systems for supporting the immediate decision making is strongly required. Especially high -tech product firms are under extreme pressure of rapid response to the demand side due to relatively short life cycle of the product. Therefore, the objective of our research is proposing a framework of estimating demand curve based on e-auction data, which is extremely easy to access and well reflect the limited demand curve in that channel. Firstly, we identify the advantages of using e-auction data for full demand curve estimation and then verify it using Agent-Eased-Modeling and Tobin's censored regression model.

• Proceedings of the KIEE Conference
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• summer
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• pp.660-662
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• 2004

Cooling demand in Korea has increased constantly. Furthermore, an evaluation and savings of cooling demand has impacted on summer DSM and investment in Korea. Absorbed cooling system uses gas. It could achieve reductions in summer peak load and increase gas demand simultaneously. However its efficiency rate is lower than electric system. Gas cooling system uses separate meter. Therefore we could analyze monthly cooling demand and derive annual uses pattern. This paper analyzes demand pattern of gas cooling and its effects on electricity savings. Also this paper presents the course of policy in electricity sector on spreading of gas cooling measures.

• Korean Management Science Review
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• v.29 no.1
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• pp.101-114
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• 2012

The demand for naval spare parts is intermittent and erratic. This feature, referred to as non-normal demand, makes forecasting difficult. Hierarchical forecasting using an aggregated time series can be more reliable to predict non-normal demand than direct forecasting. In practice the performance of hierarchical forecasting is not always superior to direct forecasting. The relative performance of the alternative forecasting methods depends on the demand features. This paper analyses the influence of the demand features on the performance of the alternative forecasting methods that use hierarchical and direct forecasting. Among various demand features variability, kurtosis, skewness and equipment groups are shown to significantly influence on the performance of the alternative forecasting methods.

• Journal of the Korean Society for Railway
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• v.12 no.3
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• pp.420-426
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• 2009

Although the amount of travel demand is a critical factor in a benefit-cost (B/C) analysis of railway investment, the travel demand changes especially for induced demand have not been considered. Therefore, the basic study of how to estimate travel demand changes after railway investment is worth investigating. This study reviews the methodologies for estimating diverted and induced demand generated after railway investment, and proposes appropriate approaches that will help railway planners to practically apply them in a case study. Further, the research stimulates the needs of consideration of the travel demand changes in the feasibility studies of railway planning.

• Journal of Preventive Medicine and Public Health
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• v.36 no.1
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• pp.39-46
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• 2003

Objectives : To investigate the availability and demand for overall cancer-related information, and to establish a basic plan for the construction of a cancer database and information system based on the research results from Korea. Methods : Postal and telephone surveys were carried out, between August 2001 and November 2001, of 323 affiliated faculty professors from medical universities and colleges in Korea. The data were analyzed with descriptive statistical methods, with regard to the present status and demand for health and cancer-related information. Results : Most (over 80%) subjects studied utilized the health-related information provided on Internet website from foreign countries, such as Medline, but similar comprehensive information system lacked in Korea. The construction of a cancer-related database of domestic research results was revealed to be in a great demand. Information on registration and statistics (52.8%), study results (48.5%) and study resources (37.4%) were the major ingredients required in the database. In constructing a database of the cancer-related research results, a full-text service, continuous updating of data, and the development of standardized user-friendly searching tool were regarded as the necessary components. The formulation of an information sharing system, regarding cancer-related clinical trials, was investigated as being quite feasible. Conclusion : This study demonstrated the great importance of cancer information systems, and much demand for an available cancer-related database based on Korean research results.

• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.403-411
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• 2005

At present, the Cournot model is one of the most commonly used theories to analyze the gaming situation in an oligopoly type market. However, several problems exist in the successful application of this model to the electricity market. The representative one is obtaining the inverse demand curve able to be induced from the relationship between market price and demand response. In the Cournot model, each player offers their generation quantity to obtain maximum profit, which is accomplished by reducing their quantity compared with available total capacity. As stated above, to obtain the probable Cournot equilibrium to reflect the real market situation, we have to induce the correct demand function first of all. Usually the correlation between price and demand appears over the long-term through statistical data analysis (for example, regression analysis) or by investigating consumer utility functions of several consumer groups classified as residential, industrial, and commercial. However, the elasticity has a tendency to change continuously according to the total market demand size or the level of market price. Therefore it should be updated as the trading period passes by. In this paper we propose a method for inducing and updating this price elasticity of demand function for more realistic market equilibrium.

• Journal of the Korean Operations Research and Management Science Society
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• v.38 no.3
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• pp.23-35
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• 2013

It is very important that the calculation of railroad track capacity in infrastructure investment analysis and train operation planning. The dwelling time is one of the factors that influence in railroad track capacity. Current research in dwelling time has been focusing on theoretical investigation, the state of the research in effective variable (dwelling time etc) is insufficient. In this paper, we clearly draw the concept of railroad track capacity and the estimate on modeling of relationship railway demand and dwelling time. Also, we compare and analyze the variation of railroad track capacity according to transit railway demand in Gyeongin Line (Guro~Inchon). This paper is expected to contribute for improving on the in-using equations and methods in train operation planning as well as for improving level of service on railway user.

• IE interfaces
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• v.5 no.1
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• pp.47-60
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• 1992

Korean government plans to expand R & D expenditures to 39.8 billion dollars (5 percent of GNP) and to secure 150,000 R & D manpower (30 per 10,000 population) until 2001. This paper deals with industrial research and development manpower and is to forecast the demand of science and technology manpower to keep pace with the economic development goals which includes advancement of science and technology. This is composed of two parts. The first part is the review of the basic concepts of this research while the second one projects and overall future demand of science and technology manpower.

• Journal of Korean Society of Rural Planning
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• v.15 no.2
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• pp.97-110
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• 2009

The objective of this research was to develop a rural settlement demand model to analyze the determinants of settlement demand of urban residents. The point aimed at from model development was deriving stated preference of potential consumers towards rural settlement through setting a hypothetical market, and using settlement subsidy as a surrogate variable for price in the demand model. The adequate demand model deducted from hypothetical market data was derived from the basis of Hanemann's utility difference theory. In the rural settlement demand model, willingness to accept was expressed by a function of settlement subsidy. Data utilized in the analysis was collected from surveys of households nationwide. According to inferred results of the demand model, settlement subsidy had a significant influence on increasing demand for rural settlement. A significant common element was found among variables affecting demand increase through demand curve shift. The majority group of those with high rural settlement demand sought agricultural activity as their main motive, due to harsh urban environments aggravated by unstable job market conditions. Subsequently, restriction of income opportunities in rural areas does not produce an entrance barrier for potential rural settlers. Moreover, this argument could be supported by the common trend of those with high rural settlement demand generally tending to have low incomes. Due to such characteristics of concerned groups of rural settlement demand, they tended to react susceptibly to the subsidy provided by the government and local autonomous entities.