• The Journal of Fisheries Business Administration
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• v.29 no.2
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• pp.97-110
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• 1998

This paper tries to estimate Korea's import demand function for fisheries using cointegration analysis. The estimation function consists of one dependent variable-import quantity of fisheries(FTIW) and two independent variables-relative price(RP) between importable and domestic products and real income(GDP). As it has been empirically found out that almost all of time series of macro-variables such as GDP, price index are nonstationary, existing studies which ignore this fact need to be reexamined. Conventional econometric method can not analyze nonstationary time series in level. To perform the analysis, time series should be differenciated until stationarity is guaranteed. Unfortunately, the difference method removes the long run element of data, and so leads to difficulties of interpretation. But according to new developed econometric theory, cointegration approach could solve these problems. Therefore this paper proceeds the estimation on the basis of cointegration analysis, because the quartly variables from 1988 to 1997 used in the model is found out to be nonstationary. The estimation results show that all of the variables are statistically significant. Therefore Korea's import demand for fisheries has been strongly affected by the variation of real income and the relative price.

• The Mathematical Education
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• v.52 no.1
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• pp.111-128
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• 2013

The purpose of this study was to examine and analyze the cognitive demand of the mathematical tasks suggested in the middle school textbooks. In particular, it aimed to reveal the overall picture of the level of cognitive demand of the mathematical tasks in the strand of geometry in the textbooks. We adopted the framework for mathematical task analysis suggested by Stein & Smith(1998) and analyzed the mathematical tasks accordingly. The findings from the analysis showed that 95 percent of the mathematical tasks were at high level and the rest at low level in terms of cognitive demand. Most of the mathematical tasks in the textbooks were algorithmic and focused on producing correct answers by using procedures. In particular, the high level tasks were presented at the end of each chapter or unit for wrap up rather than as key resources.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.679-680
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• 2011

This paper is developed to Energy Balance Flow show the flow of total energy resource be used nationally. The Energy Balance Flow is applicable of demand management factor through the analysis of foreign energy model of supply and demand and energy statistic data in the country. This study is based on and developed to Energy system management model is able to appraisal efficient of energy cost cutting, CO2 emission reduction and Energy saving at the national level calculated effect reached amount of primary energy to change of energy flow followed application of demand side management factor is able to appraisal quantitatively at the total energy to model of demand and supply.

• Journal of The Korean Society of Agricultural Engineers
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• v.54 no.6
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• pp.39-44
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• 2012

Water supply capacity and operational capability in agricultural reservoirs are expressed differently in the limited storage due to seasonal and local variation of precipitation. Since agricultural water supply and demand basically assumes the uncertainty of hydrological phenomena, it is necessary to improve probabilistic approach for potential risk assessment of water supply capacity in reservoir for enhanced operational storage management. Here, it was introduced the irrigation vulnerability characteristic curves to represent the water supply capacity corresponding to probability distribution of the water demand from the paddy field and water supply in agricultural reservoir. Irrigation vulnerability probability was formulated using reliability analysis method based on water supply and demand probability distribution. The lower duration of irrigation vulnerability probability defined as the time period requiring intensive water management, and it will be considered to assessment tools as a risk mitigated water supply planning in decision making with a limited reservoir storage.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1998.10a
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• pp.245-248
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• 1998

In this paper, as a forecasting method, the market survey for forecasting demand is introduced for the estimation of subscriber line demand in the optical access networks. The market survey method for the new multimedia services is attempted to collect information directly from customers using the questionnaires for home-users and business-users in local loops. Analysis rationale of questionnaires is suggested to estimate the number of subscriber lines. Also, two measures are presented to quantify the credibility on survey responses; one is the probability that the customer will use the multimedia services and the other is the rate that the subscriber line demand will be actually realized. The former measure is calculated based on the information on customers and the Logit analysis. The latter is obtained by the degree of customer's knowledge about specific services and the customer's willingness to use the services. Based on the values of two measures, the number of subscriber line demand can be developed for installing the optical access networks.

• Korea journal of population studies
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• v.25 no.2
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• pp.271-291
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• 2002

According to a system-wide analysis utilizing the raw data of Korean urban households survey, the expenditure elasticity estimate of alcoholic demand is around 0.71, which implies the demand for alcoholic consumption is relatively necessary The own price elasticity estimates are pretty elastic between -1.79 and 2.10. The trend of price elasticity estimates shows to be more elastic recently from the past.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.11a
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• pp.345-347
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• 2005

The electric demands increase, financial need for new power plant constructions and environmental problem have led to search for more efficient energy production and load management. To minimize the construction of power plants and reduce total power consumption include installation of demand controller to industrial applications. Accordingly to maximize the load control by the diffusion of demand controller, govermental economic supports as well as the analysis of energy saving effects. This paper presents the cost-effectiveness analysis for DSM program evaluation and case study to analyze demand controller DSM program.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.1
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• pp.16-22
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• 2017

In order to reduce costs of electricity energy at periods of peak demand, there has been an exponential interest in Demand Response (DR). This paper discusses the effect on the participants' behavior in response to DR. Under the assumption of perfect competition, the equilibrium point of the electricity market with DR is derived by modeling a DR curve, which is suitable for microeconomic analysis. Cournot model is used to analyze the electricity market of imperfect competition that includes strategic behavior of the generation companies. Strategic behavior with DR makes it harder to compute equilibrium point due to the non-differential function of payoff distribution. This paper presents a solution method for achieving the equilibrium point using the best response function of the strategic players. The effect of DR on the electricity market is illustrated using a test system.

• Journal of information and communication convergence engineering
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• v.21 no.4
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• pp.261-267
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• 2023

Public research, which requires large computational resources, utilizes the supercomputers of the National Supercomputing Center in the Republic of Korea. The average utilization rate of resources over the past three years reached 80%. Therefore, to ensure the operational stability of this national infrastructure, specialized centers have been established to distribute the computational demand concentrated in the national centers. It is necessary to predict the computational demand accurately to build an appropriate resource scale. Therefore, it is important to estimate the inflow and outflow of computational demand between the national and specialized centers to size the resources required to construct specialized centers. We conducted a logit model analysis using the probabilistic utility theory to derive the preferences of individual users for future supercomputer resources. This analysis shows that the computational demand share of specialized centers is 59.5%, which exceeds the resource utilization plan of existing specialized centers.

• KIEAE Journal
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• v.13 no.3
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• pp.91-96
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• 2013

The purpose of this study was to analyze the annual energy demand including heating, cooling and lighting according to kind of windows with transparent thin-film a-Si Building Integrated Photovoltaic(a-Si BIPV) for office building. The analysis results of the annual energy demand indicated that the a-si BIPV window was reduced by 8.4% than the clear gazing window. The base model A was combinate with a-Si BIPV window area of 67% and clear window area of 33% among the total exterior area. The model B is to be applied with low-e clear glass instead of clear glass of the base model A. The model B was reduced to annual energy demand of 1% more than the model A. Therefore, By using a-si BIPV solar module, the cooling energy demand can be reduced by 53%(3.4MWh) and the heating energy demand can be increase by 58%(2.4MWh) than clear glazing window in office building. Also, Model C applied to the high efficient lighting device to the model B was reduced to annual energy demand of 14.4% more than the Model D applied to the high efficient lighting device to the model A. The Model E applied with daylight dimming control system to the Model C was reduced to annual energy demand of 5.9% more than Model C.