• Journal of the Society of Naval Architects of Korea
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• v.50 no.3
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• pp.145-152
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• 2013

Recently, with oil price jumping and environmental issues, Green ship is paid deep attention to by ship owner, operator, builder, class and government. Fuel efficiency and reduction of $CO_2$ emissions are expected to have a strong influence on the design and operation of merchant ships. Many ship owners and operators are seeking the more economic method by the best operating route and the application of reliable and effective energy saving devices. With the Energy Efficiency Design Index (EEDI) in 2013 attention will more than ever be focused at achieving maximum fuel economy in the hydrodynamic design of hull forms, their appendages and propellers. IMO requirements for $CO_2$ emission for ships will now be implemented for vessels ordered from 1st January 2013. So far, a lot of new idea and patents have been proposed, tested, claimed and applied for various kinds of ship type. This paper shows numerical and experimental work related to a study on a energy saving devices particularly for fuller ship such as merchant vessel of Tanker and Bulker. From the bare hull wake measurements, typical upper/lower asymmetry of hull wake at the propeller disk was found. The pre-swirl duct have been designed and reviewed to recover the loss of propeller running in that condition. The general function of the pre-swirl duct was set to work against this asymmetry of wake and generate pre-swirled flow into the propeller against the propeller rotating direction.

• Journal of Energy Engineering
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• v.19 no.1
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• pp.51-56
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• 2010

Due to increase in oil price unstableness and earth warming, energy saving has been one of the most important global issues. We report a 6 sigma project that was carried out to save electrical energy in a university campus. DMAIC, the five-phase process of 6 sigma, was applied for the energy saving campaign. This paper proposes a simple method to quantify the sigma level of the electrical energy saving status and various activities to change the consciousness of all the university members. Results were very satisfied. The 6 sigma project saved about 10% of the total electrical consumption. This is approximately 50 million won a year. The success of the 6 sigma project served as a momentum to promote "Green Scholarship" that has become the center of public interest. Also, we have valuable experiences in the 6 sigma training that shows the university campus can be successfully used as a good place for the actual 6 sigma training.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.1
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• pp.1-7
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• 2015

The environmental regulations for CO2 emissions from the ship have been established recently, and fuel oil price has been increased continuously. In order to overcome these circumstances, Energy Saving Devices (ESDs) have been developed continuously to reduce the fuel oil consumption and improve the propulsive efficiency. This paper describes the trial performance of PBCF (Propeller Boss Cap Fins), SCHNEEKLUTH duct, Asymmetric rudder bulb and Mewis duct applied to handy-size bulk carriers. As a result, SCHNEEKLUTH duct is more effective than other energy saving devices at the reducing the fuel oil consumption and the improvement of the propulsive efficiency. In addition, it is confirmed that SCHNEEKLUTH duct is really effective in the vibration of the deck house. And the fuel oil consumption can also be reduced through main engine de-rating.

• Journal of Environmental Policy
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• v.9 no.4
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• pp.3-27
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• 2010

In this paper, we have analyzed the cost structure of the Korean manufacturing industry in relation to the central government's environmental investment(CGEI below) by applying translog variable cost function. Important findings are as follows. First, sufficiency degree of CGEI of 0.7230, less than optimal level of 1, causes production inefficiency. Therefore, central government should forward a strategy to raise CGEI to meet appropriate standards. In addition, inspite of the deficiency of CGEI, shadow priceis lower than market price due to q-value of 0.9572, yielding unfavorable conditions for CGEI. However, CGEI brings about increase in output, variable cost saving, and economies of scale of firms. Second, by comparing this study with an existing study(2010), we have discovered the following facts. In both studies, we find that there are deficiency of investment, unfavorable conditions in investment, economies of scale, and output increase due to investment. However, the current study has found that, CGEI, which shows efficiency by positive(+) shadow price, saves variable cost. Therefore, firms suffer from production inefficiency due to variable cost caused by a shortage of efficient CGEI. Moreover, the previous study conducted in 2010 found that investment in prevention of environmental pollution(IPEP below), which indicates inefficiency by negative(-) shadow price, cannot reduce variable cost. In such circumstances, firms yield abnormal production efficiency based on variable cost savings caused by inefficient IPEP. For this reason, firms should raise IPEP to optimal level to reduce IPEP inefficiency to achieve production efficiency by reducing variable cost.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.2
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• pp.44-50
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• 2010

Recently, the crude oil price per one barrel in 2005 cost 49.4 dollars. But the value of crude oil in 2007 had ascended 68.4 dollars which was skyrocketed 38.5[%] owing to the sudden rise of energy price. As it has been growing the necessity of energy efficiency, energy intentive companies actively try to implement energy management system It has been studied to improve the energy saving for household sector using the smart metering system which can give the information of energy prices, pattern on real time to energy consumers and voluntarily lead the activities of energy saving. In this paper, we estimated potential benefits and value of smart metering system through california test.

• Journal of Korea Water Resources Association
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• v.39 no.7 s.168
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• pp.563-574
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• 2006

Economic theory tell us, consumers always make a choice to maximize their utility. In the market system, consumers' choices are revealed and policy maker taking into account the aggregated consumers choice such as price, supply and demand. However, water resources as a public goods, therefore typically there is no market and does no aggregated information for residential water use. This study explore the consumers' willingness to pay for higher quality for residential water. Over 1,000 households responded for this survey and willingness to pay has been estimated. Furthermore, consumers' behaviors of residential water are examined. Consumers are willing to reduce the amount of water use with more than 50% of increasing water price, but stay almost constant with less than 25% of increasing which mean that current price level is not high enough to derive water saving. If consumers can have better quality of water, they willing to pay additional 16%, $153\;won/m^3/month$, more than their current price. Based on the derived information, we suggested policy direction for residential water policy.

• Journal of the Korean Regional Science Association
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• v.8 no.1
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• pp.1-29
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• 1992

The major purpose of this paper is to examine two closely related issues. An attempt is made here to examine internationally high land price in Korea from the perspectives of market fundamentals (MF) and bubble theory, respectively. Another theoretical issue, whether land speculation can result in market failure, is also examined. It has been concluded that the primary causes for the rapid increases in land prices in Korea, could be found in the perspective of MF. (1) The financial intermediaries has been controlled by the government since 1960s. Real Interest rates in the commercial banks has been controlled at the level of zero or sometimes negative; scarce financial resources has been rationed by the government. The governmental control of the bands has also resirained the development of securities market. Money, which can not find the appropri opportunity for saving in financial market, moves to land market. (2) Socially created land value, based on rapid economic gorwth and big public investment, has been appropriated mainly by the private: The effective tax rate of land holding tax has been under 0.02 percent; Real Estate Capital Galns Tax has, in fact, affected few persons, mainly because examptions and preferential taxation have been widely permitted. (3) The government has ploaced severe limitations on rural-to-urban land conversion, although the demand for urban uses has repidly grown. All factors above caused the cyclical land speculation. This, in turn, created the myth that land prices will inevitably continue to rise. Based on the myth, the growing bubble in land price has been created. This is the secondary reason for high land price relative to income in Korea. It is also shown that it is possible that speculation in land results in market failure because land is fixed in quantity and can be used for production and speculation purposes simultaneously.

• Nutrition Research and Practice
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• v.15 no.6
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• pp.747-760
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• 2021

BACKGROUND/OBJECTIVES: The consumption of home meal replacement (HMR) is increasing among college students in Korea and China. In particular, Chinese college students studying abroad in Korea (CSK) show changes in their dietary behavior after migration, and HMR consumption for meal substitution is also increasing. This study was conducted to compare the HMR consumption behaviors and HMR development needs of CSK, Chinese college students in China (CSC), and Korean college students in Korea (KSK). SUBJECTS/METHODS: The subjects were 570 college students (180 CSK, 200 CSC, and 190 KSK) who had experience of HMR consumption. Data were collected by face-to-face survey in 2019 and analyzed using SPSS 25.0. RESULTS: The majority of the subjects purchased HMR to 'saving time' and 'preventing meal skipping'. Average purchase price per HMR was about 5,000 won for the CSK and KSK, and about 3,000 won for the CSC. The most important attributes when selecting HMR for the CSK and CSC were hygiene, freshness, and taste in that order, while for the KSK were taste, price, and hygiene. Rice was preferred by the KSK while grilled and fried dishes were preferred by the CSK and CSC. In terms of development needs, dessert and meat-based side dishes were highest in all three groups. The preferred food materials for more than 50% of the subjects of all groups were beef, chicken, pork, shrimp, and squid, and spinach and Chinese cabbage in the CSK, and onion in the KSK. CONCLUSIONS: This study shows more effort is needed to develop the healthy customized HMR for college students studying in Korea and China, and that focuses are placed by CSK on hygiene and freshness, by CSC on meat side dishes, hygiene, and price, and by KSK on snacks (as meal substitutes), taste, and price.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.04a
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• pp.276-277
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• 2010

This paper deals with energy storage system for saving the energy of RTGC(rubber tired gantry crane). Advantage and disadvantage of battery, super-capacitor, and flywheel as an energy storage system were surveyed. Even if a flywheel energy storage system includes some problems such as manufacturing technique and high price, it is surveyed with a promising energy storage system In addition, RTGCs using battery or flywheel as the energy storage system were quantitatively presented through a survey of literatures. It was found that the both RTGC with those systems can reduced the waste of energy.

• Journal of Hydrogen and New Energy
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• v.31 no.4
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• pp.380-386
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• 2020

This paper represents an analysis of the economic impact of firing natural gas/diesel and natural gas/by-product oil mixtures in diesel engine power plants. The objects of analysis is a power plant with electricity generation capacity (300 kW). Using performance data of original diesel engines, the fuel consumption characteristics of the duel fuel engines were simulated. Then, economic assessment was carried out using the performance data and the net present value method. A special focus was given to the evaluation of fuel cost saving when firing natural gas/diesel and natural gas/by-product oil mixtures instead of the pure diesel firing case. Analyses were performed by assuming fuel price changes in the market as well as by using current prices. The analysis results showed that co-firing of natural gas/diesel and natural gas/by-product oil would provide considerable fuel cost saving, leading to meaningful economic benefits.