• Journal of Korean Society of Transportation
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• v.33 no.6
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• pp.520-530
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• 2015

This paper formulates the methodologies to estimate optimal congestion tolls from long-run and short-run perspectives and applies them to the highways of Seoul. An optimal long-run congestion toll is estimated with an optimal volume-capacity-ratio to minimize the total costs which consist of two components: road construction and maintenance costs and traveler costs. By contrast, an optimal short-run congestion toll is estimated with a supply-demand equilibrium which is determined by using a speed-flow function and a disaggregate modal choice model. The results of a long-run analysis for the Seobu urban expressway suggest the optimal volume-capacity-ratio of 1.35 and the optimal congestion toll of 503 Won per automobile kilometer. By contrast, those of a short-run analysis for the Mia-ro urban arterial suggest 1.31 and 420 Won, respectively. Although our results are to some degree dependent on the interest rate and time value assumed, one basic conclusion holds up: the congestions toll tested could generate substantial gains in social welfare if applied to Seoul.

• Journal of Environmental Health Sciences
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• v.42 no.5
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• pp.324-332
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• 2016

Objectives: The annual average of PM10 in Seoul was $45{\mu}/m^3$, which surpasses the WHO annual guidelines ($20{\mu}/m^3$). Most previous analyses of the effects of PM exposure have been retrospective studies using single hospital data, and fewer studies have attempted to address the relationship of PM10 and hospital costs. This study was conducted to investigate the effects of the concentration of PM10 on hospital visits, admissions and hospital costs in patients with respiratory and cardiovascular diseases. Methods: Medical data from the National Health Insurance Service and the monthly average of PM10 from National Institute of Environmental Research were used to identify the effects of PM10 on hospital visits, admissions and hospital costs. We applied Poisson regression and linear regression to perform the analysis. Results: The relative risks for admissions per $10{\mu}/m^3$ increase in PM10 were 23.11%, 10.2% and 6.9% increases for acute bronchiolitis, asthma and bronchitis, respectively. The relative risk for hospital visits per $10{\mu}/m^3$ increase in PM10 were 10.4%, 6.7% and 5.9% for chronic obstructive pulmonary disease, asthma and chronic sinusitis, respectively. For cardiovascular disease, the relative risk for admissions per $10{\mu}/m^3$ increase in PM10 were 2.2% and 2.1% increases in angina and acute myocardial infarction, respectively. A $10{\mu}/m^3$ increase in the monthly average of PM10 corresponded to 170,723,000 won (95% CI: 125,587,000-215,860,000 won), 123,636,000 won (95% CI: 47,784,000-199,487,000 won) and 78,571,000 won (95% CI: 29,062,000-128,081,000 won) increases in hospital costs for asthma, acute tonsillitis and chronic sinusitis, respectively. Conclusion: Hospital admissions for respiratory and cardiovascular disease were associated with PM10 levels. PM10 exposure is also associated with increased costs for respiratory diseases.

• Journal of Environmental Impact Assessment
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• v.8 no.2
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• pp.45-51
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• 1999

Emergy concept was used to evaluate the contributions of a dam construction to the real wealth of our economy. A dam that is proposed as a multi-purpose dam was used to illustrate emergy evaluation methodology. Models for emergy evaluation were constructed with energy systems language, a symbolic modeling language which presents network properties of systems holistically. Water supply was the most important contribution in terms of emergy, which reflects that the dam is proposed for stable water supply to a local region. Generation of electricity was the second in emergy benefits of the dam. Emergy costs were more evenly distributed among the costs which would occur as a result of the dam construction. Emergy yield ratio was 1.30 if sediments are not included, and 1.15 if sediments are included, which results in net yield in both cases. The ratio would, however, fall below 1.0 if rare species within the system boundary are lost as a result of the dam construction because of the high emergy value included in biotic species, which means that emergy costs will be greater than emergy benefits. This study illustrated a new methodology in environmental impact assessment to better manage our environments in an age of diminishing resources.

• KDI Journal of Economic Policy
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• v.24 no.1
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• pp.113-190
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• 2002

The purpose of this paper is to perform empirical studies on the impact of pollution intensity on international competitiveness using 1993 and 1998 data, and to estimate the change in environmental regulation level faced by the firms during 1993~1998. Collecting relevant data and providing them for further studies in the area are another purposes of the paper. The first method is the regression of various indices of international competitiveness on factor costs, such as labor, capital, R&D and pollution abatement costs. Goal of the regression analysis is to estimate the scarcity and comparative advantage effect of each production factor, especially environmental resource. Regression results show that those industries which employ more environmental resource have higher comparative advantage in both years, which implies that Korean firms are endowed with abundant environmental resource compared to other countries. The second method is to compute the relative scarcity indices(HOVL indices) of production factors, proposed by Leamer based on Vanek's generalized Hecksher-Ohlin Theorem. This method estimates the relative scarcity of production factors by computing factor costs embodied in import and export of commodities. This method shows similar results as the regression method; i.e., trade pattern of production factors implies that the manufacturing sector in Korea is endowed with abundant environmental resource compared to other countries. Considering population density, water resource endowment, intensity of economic activity per unit area and current air and water pollution levels, it is evident that Korea is never endowed with abundant environmental resource compared to other countries. Then the abundance of environmental resource revealed by the trade patterns of commodities and production factors implies that Korea's environmental regulation level is excessively generous compared to environmental capacity, and that this increased the environmental resource endowment supplied to firms and thus distorted the inter-industry comparative advantages. Both regression and HOVL methods, on the other hand, show that overall environmental regulation level faced by the firms has been strengthened during 1993~1998.

• Computers and Concrete
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• v.25 no.2
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• pp.111-118
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• 2020

The construction field must always explore sustainable ways of using its raw materials. Studying the environmental impact generated by reinforced concrete raw materials during their production and transportation can contribute to reducing this impact. This paper initially presents the carbon dioxide emissions from reinforced concrete raw materials, quantified per kilo of raw material and per cubic meter of concrete with different characteristic strengths, for southern Brazil. Subsequently, reinforced concrete elements were optimized to minimize their environmental impact and cost. It was observed that lower values of carbon dioxide emissions and cost savings are generated for less resistant concrete when the structural element is a beam, and that reductions in the cross section dimensions of the beams, sized based on the use of higher strength concrete, may not compensate for the increased environmental impact and costs. For the columns, the behavior differed, presenting lower values of carbon dioxide emissions and costs for higher concrete strengths. The proposed methodology, as well as the results obtained, can be used to support structural projects that have less impact on the environment.

• Journal of KIBIM
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• v.6 no.2
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• pp.19-28
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• 2016

Social costs analysis seeks to reveal the environmental effects of transportation policy. It delivers a sense of the effects of the public's daily travel and the costs that are or would be incurred from individual trips. Moreover, the accumulated total number of trips will uncover the effects of travel on society. This article shows the quantitative analysis of the economic outcomes of travel using social costs estimation methods. In order to support urban planning tasks, this research implemented analysis tool for social costs estimation by travel behavior. For a case study, a jave based application which can convert people's trip data into social costs is developed. the application used for simulating student-housing effects by estimating social costs changes. The analysis included the attributes, building scale and locational changes of the student housing as well as transforms of the students' trips.

• Journal of Environmental Science International
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• v.31 no.12
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• pp.1061-1068
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• 2022

The purpose of this study was to develop a recycling system for ozone off-gas. Although the ozone transmission rate of the injector method differs slightly depending on the ozone injection rate, it reaches approximately 99%, which is very high. During the increase in water inflow to the ozone recycling system from 2 L/min to 10 L/min, the average ozone recycling rate was 99.4% at a 1 ppm ozone injection rate, 98.6% at a 2 ppm ozone injection rate, 98.1% at a 3 ppm ozone injection rate. Ozone treatment facility operating costs can be divided into the costs of pure oxygen production, ozone production, and maintenance. The annual operating costs of ozone treatment facilities in Korea are estimated to be approximately 38.9 billion won. The annual savings are estimated to be approximately 5.8 billion won when the ozone transfer rate of the diffuser method, which is mostly employed in domestic water treatment plants, is 85% and 15% of the ozone is recycled.

• Journal of the Semiconductor & Display Technology
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• v.22 no.2
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• pp.104-111
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• 2023

The semiconductor industry, which relies on global supply chains, has recently been facing longer lead time for material procurement due to supply chain uncertainties. Moreover, since increasing customer satisfaction and reducing inventory costs are in a trade-off relationship, it is challenging to determine the appropriate safety stock level under demand and lead time uncertainties. In this paper, we propose a framework for determining safety stock levels by utilizing the optimization method to determine the optimal safety stock level. Additionally, we employ a linear regression method to analyze customer satisfaction scores and inventory costs based on variations in lead time and demand. To verify the effectiveness of the proposed framework, we compared safety stock levels obtained by the regression equations with those of the conventional method. The numerical experiments demonstrated that the proposed method successfully reduces inventory costs while maintaining the same level of customer satisfaction when lead time increases.

• Korean Journal of Organic Agriculture
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• v.18 no.1
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• pp.1-19
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• 2010

This paper evaluates potential environmental impacts and external costs on rice production of Korea. The investigation is based on LCA in agricultural area which estimates inputs and outputs of rice production system in quantitative way. The results show that environmental impacts on organic rice(4.49E-08 DALY/kg) is level on 4.5% out of conventional rice(9.97E-07 DALY/kg). The external costs of organic and conventional rice are 4.04won/kg and 89.52won/kg respectively. The balance of both organic and conventional rice which is 85.48won/kg represents monetary value on improvement of environmental effects as producing organic rice.

• Environmental and Resource Economics Review
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• v.20 no.3
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• pp.567-593
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• 2011

In 2005, five Korean generation companies suggested to include non-fuel ancillary costs incurring in the process of managing fuels and ashes as variable costs in Korean Cost-Based Pool. OLS analysis seeking statistical relation with the amount of generation did not provide sufficient ground for such argument. However, some cost items in this category showed meaningful statistical relation for certain generation facilities hinting some possibilities for the candidate of variable costs in the future. Time lag related to cost evaluation, problems related to inventory control and accounting method related to this may block the statistical relationship with the amount of generation. Unified criteria and standardization of the data are necessary before we proceed further to consider them as variable costs.