• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.9
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• pp.507-512
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• 2004

HTS (High Temperature Superconducting) Transformer has the several useful characteristics in the viewpoints of technical and economical. Especially, an HTS transformer replaces the copper wire coils in a conventional transformer with lower loss HTS wire. In addition, inexpensive, environmentally benign liquid nitrogen replaces the conventional oil as the electrical insulation (dielectric) and provides the necessary cooling for the HTS transformer Therefore, the Life-cycle cost of an HTS transformer is much more attractive than conventional because it is more energy efficient, lighter in weight, smaller in size, and environmentally compliant. HTS transformer can be the best way to replace with conventional transformer in the future. In these days, companies world-wide have conducted researches on HTS transformer. A development project for a 154kV HTS transformer is proceeding at a research center and university in Korea. In this paper, we investigate the expected price of HTS transformer to have a merit in viewpoint of economic aspect. First, life-cycle cost of conventional transformer is calculated and based on this, the expected price of HTS transformer is evaluated. which HTS transformer is competitive against conventional transformer.

• Environmental and Resource Economics Review
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• v.19 no.2
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• pp.413-440
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• 2010

Since 2000, as importance of sourcing energy emphasized caused by instability of international oil price, interests toward Caspian countries as an alternative markets has increased. Especially, Azerbaijan, as middle Asian emerging exporting country, has performed drastic economic boom because of massive amount of foreign capital flowed in and construction of BTC pipeline. However, despite this economic surge, there are unbalanced economy which is merely focusing on energy industry and pressure from increase in real exchange rate and inflation. In order to analyze the sustainability of Azerbaijan economy, the total sample time period of this paper is from January 2001 to December 2007 and the term is divided into before and after BTC line construction. Vector Error-Correction Model has been applied to analysis confirming short-term and long-term effect. As a result, Azerbaijan now face the symptoms of the recession during the time period and this is due to high oil price and increase in export influenced by BTC oil pipeline resulting in decrease in real interest rate. This conclusion is to affect competitiveness of manufacturing industry, base industry for economic proliferation, in a negative way.

• Journal of Advanced Marine Engineering and Technology
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• v.27 no.3
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• pp.412-420
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• 2003

This study describes the merits of PWM control of hydraulic system using high speed on-off valves. Generally, Electro-hydraulic valves can be classified into two classification: valves which are controlled by analog signal and which are controlled by digital. The former includes hydraulic servo valves and proportional valves which require A/D converters as interface to digital computer and too costly and sensitive to oil contamination because of complexity in structures. The latter includes high speed on-off valves which do not require A/D converters because they are normally operated in a pulse width modulation(PWM) method, and are low in price and robust to oil contamination because of their simple structures. The objectives of this study is to analyze the limit cycle which regularly appear in the position control system using 2/2way high speed on-off valves and to give a criterion for the stability of this system. The nonlinear characteristics of PWM and cylinder friction of this system are described by harmonic linearization and the effects of parameter variations to the system stability are simulated.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.204-209
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• 2006

Despite the recent depression of the construction industry, overseas plant market especially Middle East plant market is booming owing to the high oil price. Since many Middle Eastern countries are placing orders of big scale projects based on the high oil price, Korean EPC contractor are trying to get over the depression through theses plants. Presently, since the plant market is in prosperous condition in general, it is not hard to get overseas orders; however the original licenses that requirehigher technology and high added values are exclusive for advanced engineering companies which great difficulty is predicted for developing countries like us to join the crowd. Therefore, the objective of this study is to propose establishment of material management system on the filed to gain optimized effect of material management in connection with procurement system that all the procurement related personals execute tasks in advanced level by systemizing the task operation within the knowledge and task ability in time for plant construction procurement as a method to strengthening the competitiveness of Korean companies.

• Korean Journal of Medicinal Crop Science
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• v.28 no.6
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• pp.421-427
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• 2020

Morus alba, Anti-obesity, C57BL/6 Mice, Expression, Flavonoid, Gene, Mulberry Background: The seed oil of Zanthoxylum schinifolium S. et Z. (sancho) is a traditional cooking oil that has long been sold at a very high price however, depending on the method of extraction and storage, this oil becomes rancid occurs very quickly. Therefore, this study aimed to find a material that prevents rancidity and improves the storage properties of sancho oil. Methods and Results: Sancho oil was extracted using an extraction press, and acid values were compared with commercially available vegetable oils, sancho oil had a higher acid value than other vegetable oils. A very high acid value was observed in sancho oil stored for 6 months, regardless of temperature, requiring an effective storage method. The high acid value and the decrease in turbidity of sancho oil are dependent on the days of sedimentation. Treatment with sodium bicarbonate by concentration resulted in minimal changes in acid value over time. However, minor differences were detected among the treatment concentrations. Ascorbic acid was added to maximize the effect of sodium bicarbonate, and it was observed that ascorbic acid did not improve the antioxidant effect. The sodium bicarbonate and ascorbic acid mixture resulted in minimal change in acid value at temperature up to 25℃. Conclusions: Sancho oil becomes rancid very quicky and requires efficient storage techniques. Sodium bicarbonate and ascorbic acid have been proven to be useful as safe anti-racidity agents without causing harm to humans.

• Journal of the Korean Professional Engineers Association
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• v.41 no.3
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• pp.50-54
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• 2008

Recently most companies require various type of energy sources, in order to be more energy efficient in their plant due to the increasing current oil price. So, the multi-national companies are shaping ideas how to reduce energy costs and use substitute energy. The purpose of this study Is to attempt to save energy by making more valuable high pressure steam through TVR(Thermal Vapor Recompressor) from the surplus low pressure steam of HRB(Heat Recovery Boiler) in sulfuric acid plant.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.410-411
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• 2008

A topology optimization technique to develop extremely light trailer frame structure is performed due to the strong needs of the customers and makers owing to high level of oil price. First, the overall layout of the frame is derived using topology optimization and then, final specification is also derived utilizing DOE optimization technique for mass product.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.782-783
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• 2007

Exhaustion of fossil fuel resources and high oil price, and furthermore environmental crisis due to emission of carbon dioxide from fossil fuel are serious problems in these days. In order to overcome these problems it is necessary to find and utilize the every energy saving measures and to make maximum utilization of renewable energy resources. The objective of this paper is to develop an instrument to verify the feasibility of Co-Generation System application in an Apartment Complex.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.9 no.2
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• pp.8-15
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• 2013

Recently, an interest in the use of renewable energy has been growing up due to the rise of raw material price, international oil price and depletion of fossil energy. Ground source heat pump system has a high efficiency by using the constant temperature of underground and various types of the systems have been installed and utilized in the building. there are few studies on the system performance factors in the SCW system. Furthermore, even though the performance of the system depends on the temperature of heat source, the research on their relationship is rare. In this research, in order to analyze the performance factor for the open-loop system the monitoring of the real building with the standing column well systems and the simulation with building model were conducted.

• Resources Recycling
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• v.6 no.2
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• pp.12-21
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• 1997

Plastics waste constitutes approximately 23% by volume of the municipal solid waste(MSW) generated in the U.S. each year, and have slow rate of degradation in the environment. Therefore, there is a great deal of public pressure to recycle plastics, and more than 100 million people participate in the curbside recycling programs. Despite the high level of public interest, only 3.5% of the plastic are recycled, which is substantially lower than the recycle rates of other materials such as paper fibers, glass, and iron. Although a large part of the reason is due to the low price of virgin polymers, which in turn is due to the low price of oil, it is possible to make the plastics recycling as a profitable business by developing advanced technologies. In this communication, various methods of separating pplastics from metals and from each other are discussed.