• 한국전산유체공학회:학술대회논문집
• /
• 2001.05a
• /
• pp.144-148
• /
• 2001

Characteristics of high temperature rocket nozzle flow is discussed along with the aspects of computational analysis. Three methods of nozzle flow analysis, frozen-equilibrium, shifting-equilibrium and non-equilibrium approaches, were discussed those were coupled with the methods of computational fluid dynamics. A chemical equilibrium code developed for the analysis of general hydrocarbon fuel was coupled with three approaches of nozzle flow analysis, and a test was made for a bell nozzle at typical operation condition. As a results, the characteristics of the approaches were discussed in aspects of rocket performance, thermal analysis and computational efficiency.

• Journal of Environmental Policy
• /
• v.11 no.4
• /
• pp.131-154
• /
• 2012

Existing researches on tax efficiency of environmental taxes mostly focuses on taxes imposed on the consumption process of the final output, or goods that create pollution during the input process of intermediate goods. The assumption here is that there is a significant relation between the consumption of polluting goods and the pollution itself. However, in reality they are not identical. This signifies that the above assumption may distort the actual results. This study classifies environmental tax into two different forms, output tax and emission tax. Theformer is the tax that is imposed on the consumption of polluting goods, while the latter is directly levied onto the emission of pollution. It then compares the efficiency of these taxes through the computational general equilibrium simulations. After analyzing the simulation, it was proven that the direct imposition on pollution, or environmental tax as emission tax, was more effective in terms of tax efficiency. Furthermore, these results were revealed as irrelevant to the assumption of homotheticity in utility function. Thus, if market-distortionary tax already exist, then the effectiveness of revenue neutral environmental tax reform will be sensitive to the assumption of homotheticity for utility function. However, environmental taxes as emission taxes have been shown to be more effective in tax efficiency than output taxes.

• Tunnel and Underground Space
• /
• v.25 no.3
• /
• pp.264-274
• /
• 2015

In this study, the applicability of geotextile mesh soil nails on slopes was evaluated by numerical analysis to reduce environmental problems which a general soil nailing might produce and to improve its economical efficiency and construction convenience. To this end, in situ pull-out tests were conducted for both general soil nail and geotextile mesh soil nail and their pull-out characteristics were analyzed. Also, finite difference method was used to verify the suitability of numerical simulation. Parameters for nail and ground conditions were selected and sensitivity analysis was performed for the evaluation of slope stability. In addition, analysis was performed by limit equilibrium method which is widely used for slope stability analysis in practice. As a result, if the nail diameter was same, there is no big difference between geotextile mesh soil nails and general soil nails in terms of slope stability. Therefore it can be expected that geotextile mesh soil nails could be effective for slope reinforcement since they could keep a slope as stable as general soil nails and give better economical efficiency and construction convenience than general soil nails.

• The Journal of the Korea Contents Association
• /
• v.18 no.11
• /
• pp.430-446
• /
• 2018

In this paper, we conducted a comparative study on the methodology for impact analysis as the economic grounds for formulating policy and investment plan concerned with utilizing spectrum resource. In order to provide numerical results for objective comparison and selection among policy and investment planning, methods to be analyzed are focused on quantitative methodology based on mathematical models, consequently the utility and limits of econometric model, input-output analysis, computable general equilibrium and system dynamics are compared from various viewpoints including analysis cost. Besides, we compared the methodologies in the standpoint of utilizing spectrum and discussed the recent findings of mixed models combining multiple methodologies to exploit the advantages of each methodology and to offset the limit. Results of the research can be used as reference indicators to select the method that conforms to the purpose and priority of analysis verifying the efficiency of execution of policies and investment plans.

• Journal of the Korean Regional Science Association
• /
• v.10 no.2
• /
• pp.45-51
• /
• 1994

The purpose of this paper is to present the optimal investment conditions of SOC facilities for maximizing regional social welfare in implementing the urban development project in the theoretical fashion. Particularily, SOC facilities are divided into both supply-side($P_s$) and demand-side SOC ($P_d$) in the paper. General equilibrium analysis from the intra-regional viewpoint by utilizing Pareto's Optimal Conditions and by revising Samuleson's Conditions for public goods($P_s$ and $P_d$) results in the optimum pattern of SOC investment. The following are important implications from the analysis. First, rather than the pursue social equity, SOC investment is to resolve the issue of efficiency to activate the regional economy. Second, the marginal rate of transformation (MRT) between $P_s$ and $P_d$ in the region is to play a significant role in structuring SOC investment plant of local government for social welfare maximization. Third, the optimal SOC investment policy based on this regional economy but also to generate the enhancement of soical amenities of the residents.

• Environmental and Resource Economics Review
• /
• v.11 no.1
• /
• pp.145-184
• /
• 2002

This paper analyzes the impact of imposing carbon tax on the Seoul economy to reduce Greenhouse Gas(GHG) emission. We construct the social accounting matrix of Seoul, specifying energy and transport sectors which is closely related to air pollution. Then, we formulated the computable general equilibrium (CGE) model of seoul and performed scenario analysis. The main result shows that the economic cost of GHG reduction is quite large but the health benefit is also considerable. It also suggests the importance of cost effective measures such as the development of new energy technology and the improvement of energy efficiency.

• Journal of Labour Economics
• /
• v.42 no.2
• /
• pp.1-35
• /
• 2019

This paper compares the effects of income transfer and wage subsidy in a simple general equilibrium model. The redistributive effects of both policies are smaller, the more intensive in low wage workers are the luxury goods production. Wage subsidy contributes more to employment and GDP relative to income subsidy, but its redistributive effects can be smaller depending on the elasticities of labor demand supply. More complete empirical analysis appears due on the effects of both policies in order to design an optimal mix of efficiency and equity.

• Journal of Korea Planning Association
• /
• v.53 no.7
• /
• pp.67-86
• /
• 2018

This paper attempted to analyze impacts of transition in electricity generation system on a national economy and environmental level in Korea using a recursive computable general equilibrium(CGE) model. In particular, the paper presented a hybrid model combining the top-down CGE model with the bottom-up model which describes the structure of electricity production in detail. The impacts were analyzed by two policy scenarios base on the basic plan for electricity supply and demand proposed by the Korean government. As a result, the paper specifically showed that there exists a trade-off relationship in the policy-making between economic efficiency and environmental level. The paper also suggested that the transition in electricity generation system should be done more gradually and carefully.

• Journal of the Korea Convergence Society
• /
• v.10 no.1
• /
• pp.205-214
• /
• 2019

In Korea, the first-price sealed bid auction and the constrained mean-price sealed bid auction(buchal-je in Korean) have been used alternatively as procurement auctions. In this paper, we characterize the constrained mean-price sealed bid auction in the context of mechanism design. We consider the general ?-bidder case in which each bidder has private information. Under the assumptions of uniformly distributed valuations and linear strategies, we derive the equilibrium of the constrained mean-price sealed bid auction. Furthermore, we analyze the efficiency and the expected revenue of this auction mechanism in comparison with the first-price sealed bid auction. Finally, we conclude with the critical remarks on the practical intention of the government which uses this auction.

• Environmental and Resource Economics Review
• /
• v.15 no.2
• /
• pp.201-245
• /
• 2006

We applied general equilibrium model to analysis the economic impact of international emission trading by sector and the efficiency of the Convention to study whether Climate Change Convention satisfy the efficiency. We divided the world as 4 groups : USA, OECD members w/o USA (OEC), Former Soviet Union (FSU) and Developing countries (DEV). Compared to no trading, global trading would accomplish the same environmental effect with less cost as much as 97.8 billion$, which is the surplus of trading. However, half of it is taken by USA and 20% by OEC. FSU and DEV have only 18% and 10%. This result suggest the two things. First, the emission trading is effective as far as the participation of developing countries are guaranteed. If they do not take part in the coalition and emit the leakage, it may threaten the stability of the international trading coalition. Second, we found the logical ground of the side payment for developing countries. The permit buying countries take more share of the surplus under the emission trading, while the energy sector of developing countries shrinks to sell permits, which may adversely affect to economic growth of the countries. Therefore, the Annex-I countries need to provide side payment to lead the participation of the developing countries.