• Journal of Hydrogen and New Energy
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• v.21 no.6
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• pp.595-603
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• 2010

This paper deals with an economic evaluation of domestic window type photoelectrochemical hydrogen production utilizing solar cells. We make some sensitivity analysis of hydrogen production prices by changing the values of input factors such as the initial capital cost, the solar to hydrogen conversion efficiency, and the system duration time. The hydrogen production price of the window type photoelectrochemical system was estimated as 1,168,972 won/$kgH_2$. It is expected that hydrogen production cost can be reduced to 47,601 won/$kgH_2$ if the solar to hydrogen conversion efficiency is increased to 14%, the system duration time is increased to 20,000 hours, and the initial capital cost is decreased to 25% of the current level. We also evaluate the hydrogen production cost of the water electrolysis using the electricity produced by solar cells. The corresponding hydrogen production cost was estimated as 37,838 won/$kgH_2$. The photoelectrochemical hydrogen production is evaluated as uneconomical at this time, and we need to enhance the solar to hydrogen conversion efficiency and the system duration time as well as to reduce prices of the system facilities.

• Journal of Korea Port Economic Association
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• v.26 no.1
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• pp.1-19
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• 2010

This paper focuses measuring the efficiency of container yards on container terminals in Busan (Gasungdae, Shinsundae, Gamman, New Gamman, Uam, Gamchon, PNC) and Gwangyang(GICT, KEC, Dongbu, KIT) using Data Envelopment Analysis(DEA) approach. Container terminals in Busan and Gwangyang play an important role in the region's economic development. The results show that Shinsundae was an efficient DMU during the period of 2007 to 2009, while Gamman, New Gamman and PNC were efficient terminals in 2009. The very inefficient terminals were shown to be GICT, KEC, Dongbu and KIT. GICT(2009), KEC(2009), Dongbu(2008-2009), KIT(2009) on Gwangyang Port were found to be relatively the inefficient terminals in terms of the returns to scale. This study also finds that the efficiency of Shinsundae terminal was so high as to be abel to keep its efficiency in spite of the additional increase of the inputs from 2007 to 2009. Gamman terminal was in the decreasing returns to scale in 2009, while the other terminals were in the increasing returns to scale. It means that we are able to improve the efficiency of the Gamman terminal with increasing returns to scale through enlarging the scale.

• Korean Journal of Community Nutrition
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• v.23 no.5
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• pp.385-396
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• 2018

Objectives: This study aims to evaluate the economic efficiency of a nutrition management program for children under 5 years of age in Kenge, Kwango District, Democratic Republic of the Congo (DR Congo) from 2014 to 2016. Methods: The economic efficiency of a nutrition management program for children under 5 years of age who have recovered from malnutrition status was evaluated using a cost-benefit analysis. The costs were analyzed according to the executed budget incurred during the project period. The benefits were estimated as the monetary value of the saved lives of children under 5 years of age. The economic efficiency of the program was determined by the Benefit-Cost Ratio (BCR). The BCR was calculated by dividing the total discounted benefit by the total discounted costs. The project is economically efficient when the BCR is greater than 1. Results: The costs of the nutrition management program were calculated as 1,677,609,648 Korean Won (KRW). A total of 2,466 children survived with improved malnutrition status through this program. The benefit for the reduction of mortality for children under 5 years of age was estimated to be 6,814,354,467 KRW, the estimated value of life for 2,466 children. The BCR was 4.06. Conclusions: The nutrition management program for children under 5 years of age in DR Congo was found to be a cost-effective project. Successful and efficient Official Development Assistance (ODA) for a health project requires integrated and comprehensive strategies and specialized international development consulting to improve efficiency. Future nutrition management programs should take into account the national health program to maintain the sustainability of the project.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.5
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• pp.372-378
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• 2016

A mound was constructed to install a caisson and sofa blocks underwater. The mound riprap, which were of uniform grade, size, shape, and specific gravity, formed the foundation for the support superstructure. Also, rubble leveling works were performed before installing structures such as caissons. In this study, underwater construction equipment was developed with a remotely controlled operating system and underwater environment monitoring system for unmanned underwater rubble leveling work. The performance of the developed equipment was verified using on-land and underwater tests. In addition to the performance verification, the construction process and economic efficiency of the equipment should be checked before applying it to the real construction field for commercial purposes. In this paper, a construction process using the developed equipment was proposed and compared with the existing rubble leveling method. The results demonstrated that the new construction method has higher economic efficiency and safety than the existing construction method.

• Korean Journal of Construction Engineering and Management
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• v.9 no.3
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• pp.185-193
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• 2008

In order to improve work efficiency in high-rise apartment building construction, it is required to establish the major criteria and practical method for selecting the construction lifts. It is necessary to analyze work efficiency and economic feasibility depending on speed, size and capacity of lifting equipment and characteristics of construction projects. The purpose of this research is to develop the fundamental process and information for selecting the lift in order to plan and manage the material lifting and laborers' vertical transporting in the high-rise apartment building projects more effectively. In order to satisfy the objective of the research, work performance of the lifting machines with different speed and carrying capacity is analyzed under the practical constraints. In addition, potential economic evaluation is conducted. One of the significant findings of the research is that the mid-speed lift shows 43% improvement in work efficiency compared with the low-speed lift. The results of the research will be used as the basis for developing the further optimal lifting management system.

• Clean Technology
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• v.29 no.1
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• pp.53-58
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• 2023

This study shows the summary of the economic performance of excess electricity conversion to hydrogen as well as methane and returned conversion to electricity using a fuel cell. The methane production process has been examined in a previous study. Here, this study focuses on the conversion of methane to electricity. As a part of this study, capital expenditure (CAPEX) is estimated under various sized plants (0.3, 3, 9, and 30 MW). The study shows a method for economic optimization of electricity generation using a fuel cell. The CAPEX and operating expenditure (OPEX) as well as the feed cost are used to calculate the discounted cash flow. Then the levelized cost of returned electricity (LCORE) is estimated from the discounted cash flow. This study found the LCORE value was ¢10.2/kWh electricity when a 9 MW electricity generating fuel cell was used. A methane production plant size of 1,500 Nm³/hr, a methane production cost of $11.47/mcf, a storage cost of $1/mcf, and a fuel cell efficiency of 54% were used as a baseline. A sensitivity analysis was performed by varying the storage cost, fuel cell efficiency, and excess electricity cost by ±20%, and fuel cell efficiency was found as the most dominating parameter in terms of the LCORE sensitivity. Therefore, for the best cost-performance, fuel cell manufacturing and efficiency need to be carefully evaluated. This study provides a general guideline for cost performance comparison with LCORE.

• KDI Journal of Economic Policy
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• v.39 no.4
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• pp.25-50
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• 2017

Whereas a large variety of previous studies show mixed results regarding the relationship between public investment and economic outcome, several studies have been conducted on related issues in Korea. The present study deals with the effect of public investment in Korea on economic growth and productivity. Using administrative data, it exploits three different methodologies: the total factor productivity approach, production function approach, and stochastic frontier production function approach. The results of this study show that public investment has a statistically significant effect on economic growth. However, it contributes little to enhance productivity. It is explained that there exists inefficiency of production in the Korean economy. These findings indicate that public investment has played a central role in the direct input factor and not in indirect role in Korea. Thus, it is necessary for public investment policies to concentrate on enhancing the efficiency of the Korean economy.

• Journal of Environmental Policy
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• v.2 no.2
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• pp.81-103
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• 2003

This paper compares the environmental economic performance of the South Korean and the German economy during the last decade. The analysis is based on comparable data from the Environmental Economic Accounts (EEA). The EEA is a satellite account to the National Accounts which enhances the conventional economic accounts by a description of the interactions between the economy and the environment. The data from the EEA and the national accounts are fully compatible. In absolute terms the environmental pressures caused by economic activities were with regards to the environmental factors used for the analysis generally lower in South Korea than in Germany. If the use of environmental factors is related to each country's gross domestic product (environmental productivities) a lower level of environmental productivity can be observed for most of the environmental factors in South Korea compared to Germany. For example in 1999 energy and $CO_2$ productivity were about two fifths of the German level. This corresponds to the relation regarding labour productivity (Gross domestic product per employment).

• The Korean Journal of Community Living Science
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• v.13 no.1
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• pp.25-40
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• 2002

Recently the rural women's role has been changed from assisting men to leading major farm work. However, contribution of women in the rural area has not beers fairly evaluated. Hence, it has been difficult for the rural women to receive the reasonable compensation if they injured, had some disasters or were divorced. Therefore this study tried to suggest economic methods such as market cost approach, opportunity cost method and shadow wage method for evaluating rural women's labor. It might provide some information for helping to establish the status of rural women as a income earner through estimating money value of labor contributed by rural women and furthermore, be useful information to improve the efficiency of farm labor by exploring the relationship between value of labor and actual income. Hence, it might help improve the economic situation and life at home of rural women, solve difficulties in the real life and reduce disparity of economic distribution between urban and rural area.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.2
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• pp.121-128
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• 2004

This paper presents a new approach for determining an accurate incentive levels of Direct Load Control (DLC) program using sequential Monte Carlo Simulation (MCS) techniques. The economic analysis of DLC resources needs to identify the hourly-by-hourly expected energy-not-served resulting from the random outage characteristics of generators as well as to reflect the availability and duration of DLC resources, which results the computational explosion. Therefore, the conventional methods are based on the scenario approaches to reduce the computation time as well as to avoid the complexity of economic studies. In this paper, we have developed a new technique based on the sequential MCS to evaluate the required expected load control amount in each hour and to decide the incentive level satisfying the economic constraints. In addition, the mathematical formulation for DLC programs' economic evaluations are developed. To show the efficiency and effectiveness of the suggested method, the numerical studies have been performed for the modified IEEE reliability test system.