• Economic and Environmental Geology
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• v.41 no.5
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• pp.485-496
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• 2008

The purpose of this study is to suggest potential target countries for the package deal projects of coal resources development and power industry by analyzing data on global coal demand and supply and electrical infrastructures. Indexes such as coal deposits, types of coal deposits, electrical coal consumptions per capita, and gross domestic products per capita of the countries need to be evaluated for determining the potential target countries for the package deal projects. Based on the evaluation of the indexes of countries, the potential target countries for the package deal project are underdeveloping Asia or Africa countries such as Bangladesh, Mongolia, and Nigeria.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.7 no.2
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• pp.77-90
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• 2012

As the influence of service industry into domestic economy is increasing, it also has been influenced more powerfully at the domestic GDP(Gross Domestic Product) relative importance and employment relative importance continuously. By means of these reason, the Korean government announced the synthetic countermeasure for strengthening the competitive power of service industry in December, 2006. After then, it announced phase I of 'service industry advancing plan' which is concrete execution plan in April, 2008. Also, it is announced to announce phase II plans in september, 2008 and phase III plan in December, 2008 additionally. Service quality is the most powerful competitive means at service marketing and a key point for improving service productivity. The improvement of service quality has considerable influence on survival and profitability of service industry. Therefore, the study of objective service quality measurement in service industry is very important issue. The purpose of this study is to suggest a measurement model of service quality using fuzzy theory and AHP which measuring service quality objectively in subjective environment. It is expected that this study will help the improvement of competition power of service industry as well as establishment of effective decision-making.

• Plant Journal
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• v.4 no.3
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• pp.60-65
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• 2008

Power plant industry has been developed at high-capacity, high-technology, and innovation. Steam turbine became the most useful equipment that dominate more than 50% of all the world electricity production. And developed new materials of the turbine blade and extended length of the turbine last blade brought reform in steam turbine performance upgrade. In this paper, when do partial load driving in high-capacity steam turbine, optimum driving method found whether there is something. In operating steam turbine, there is a lot of loss from secondary wake and throttle of the 1st stage nozzle by the biggest leading factor that load fluctuation affects in high-pressure steam turbine performance. Effect of internal efficiency by 1 stage nozzle is the biggest here, but here fluid flow and flow analysis were not yet examined closely definitely. So, Analyzed design data and acceptance performance test result to applying subcritical pressure drum type 560 MW, supercritical-pressure once through type 500 MW, and 800 MW steam turbines actually. In conclusion, at partial load driving, partial arc admission(PAA) is more efficient than full arc admission(FAA) efficiency. This is judged by because increase being proportional with gross energy of stream that is pressure - available energy if pressure of stream that is flowed in to the turbine increases, available energy becomes maximum and turbine efficiency improves. Therefore, turbine performance is that preview that first stage performance fell if decline is serious in partial load because first stage performance changes according to load.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.11
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• pp.1979-1985
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• 2003

Fretting is a kind of surface degradation mechanism observed in mechanical components and structures. The fretting damage decreases in 50-70% of the plain fatigue strength. This may be observed in the fossil power plant and the nuclear power plant used in special environments and various loading conditions. The thermal degradation of material is observed when the heat resisting steel is exposed for long period time at the high temperature. In the present study, the degraded 1Cr-0.5Mo steel used for long period time at high temperature (about 515$^{\circ}C$) and artificially reheat-treated materials are prepared. These materials are used for evaluating an effect of thermal aging on the fretting fatigue behavior. Through the experiment, it is found that the fretting fatigue endurance limit of the reheat-treated 1Cr-0.5Mo steel decreased about 46% from the non-fretting fatigue endurance limit, while the fretting fatigue endurance limit of the degraded 1Cr-0.5Mo steel decreased about 53% from the non-fretting fatigue endurance limit. The maximum value of fatigue endurance limit difference is observed as 57%(244 MPa) between the fretting fatigue of degraded material and non-fretting fatigue of reheat-treated material. These results can be a basic data to a structural integrity evaluation of heat resisting steel considered to thermal degradation effect.

• Plant Journal
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• v.12 no.3
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• pp.39-45
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• 2016

Each of fuel consumption per hour was measured at the 320 MW and 380 MW generator output while changing mixing ratio of bio fuel oil to 50%, 80% and 100%. Fuel consumption per hour was increased from 11.0% to 20.4% as mixing ratio of bio fuel oil was changed from 50% to 100% at the 320 MW generator output comparing with fuel consumption per hour in case of bunker-C oil single firing. Fuel consumption per hour was also increased from 12.0% to 21.1% as mixing ratio of bio fuel oil was changed from 50% to 100% at the generator output 380 MW. Furthermore, it was confirmed that plant efficiency was decreased as mixing ratio of bio fuel oil was increased from 50% to 100% as a result that plant efficiency was calculated using the measured fuel consumption per hour, the generator output and the gross heating value.

• Journal of The Korean Astronomical Society
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• v.52 no.5
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• pp.159-172
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• 2019

It is known that the number of astronomers of a country registered to the International Astronomical Union (IAU) is correlated with that country's gross domestic product (GDP). However, the robustness of this relationship could be doubted, as the fraction of astronomers joining the IAU differs from country to country. Here we revisit this correlation by using more recent data, updated as of 2017. We find a similar correlation by using the total number of astronomers and astrophysicists with PhD degrees that are working in each country, instead of adopting the number of IAU members. We confirm the existence of the correlation. We also confirm the existence of two subgroups within this correlation. One group consists of advanced European countries having a long history of modern astronomy, while the other group consists of countries having experienced recent rapid economic development. In order to determine the cause for the correlation, we obtained the long-term variations of the number of astronomers, population, and the GDP for a number of countries. We find that the number of astronomers per capita for recently developing countries has increased more rapidly as GDP per capita increased, than that for fully developed countries. We collected demographic data of the Korean astronomical community and find that it has experienced recent rapid growth. From these findings we estimate the proper size of the Korean astronomical community by considering Korea economic power and population. The current number of PhD astronomers working in Korea is approximately 310, but it should be 550 in order for it to be comparable and competitive to the sizes of the Spanish, Canadian, and Japanese astronomical communities. If current trends continue, this number will be reached by 2030. In order to be comparable to the German, French, and Italian communities, there should be 800 PhD astronomers in Korea. We discuss ways to overcome the vulnerability of the Korean astronomical community, based on the statistics of national R&D expenditure structure in comparison with that of other major advanced countries.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.30 no.3
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• pp.295-303
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• 2012

Clarify wind energy productivity depends on three factors: the wind probability density function(PDF), the turbine's power curve, and the air density. The wind PDF gives the probability that a variable will take on the wind speed value. Wind shear refers to the change in wind speed with height above ground. The wind speed tends to increase with the height above ground. also, Wind PDF refers to the change with height above ground. Wind analysts typically use the Weibull distribution to characterize the breadth of the distribution of wind speeds. The Weibull distribution has the two-parameter: the scale factor c and the shape factor k. We can use a linear least squares algorithm(or Ln-least method) and moment method to fit a Weibull distribution to measured wind speed data which data was located same site and different height. In this study, find that the scale factor is related to the average wind speed than the shape factor. and also different types of terrain are characterized by different the scale factor slop with height above ground. The gross turbine power output (before accounting for losses) was caculated the power curve whose corresponding air density is closest to the air density. and air desity was choose two way. one is the pressure of the International Standard Atmosphere up to an elevation, the other is the measured air pressure and temperature to calculate the air density. and then each power output was compared.

• Tribology and Lubricants
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• v.34 no.5
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• pp.197-207
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• 2018

Thermal deterioration of fuel due to long-term storage influences engine performance and causes malfunctions. Fuel stability is usually evaluated via heat resistance and thermal stability during a brief heat shock at high temperature; storage stability in this scenario means that there is very little change in the quality of the fuel during long-term storage. In addition, rubber-based products such as oil seals, O-rings, and rubber hoses can influence the quality of the fuel. When these rubber products are in contact with fuel, they can swell, mechanically weaken, and occasionally crack, thus leaking low molar weight rubber and additives including plasticizer and antioxidant into the fuel to degrade its properties and shorten its useful lifetime. This study determines the thermal stabilities of three kinds of synthetic fuels by evaluating their low temperature kinematic viscosities, chemical composition changes via GC analyses, gross heat of combustion, and color changes. We evaluate the compression set of O-rings by immersing one NBR and two FKM rubber O-rings in the three synthetic fuel samples in airtight containers at variable storage temperatures for six months; from this, we estimate the lifetimes of the O-rings using the Power law model. There were very little changes in the chemical compositions and gross heat of combustion after six months of the experiment. The lifetimes are thus dependent on the materials of the rubber products, and in particular, the FKM O-ring was calculated to have a theoretical lifetime of 200 to 5,700 years. These results indicate that the synthetic fuels maintain their physical properties even after long-term storage at high temperatures, and the FKM O-ring is suitable for long-term sealing of these fuels.

• Journal of Navigation and Port Research
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• v.41 no.6
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• pp.359-364
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• 2017

This study examined business acts related to leisure boats, so as to investigate the differences of regulations and things to be supplemented, as well as to suggest improvement measures. In order to achieve this purpose, the authors analyzed the respective legislations. The Acts on businesses using leisure boats(or power-driven water leisure crafts) are the Marine Transportation Act, Excursion Ship and Ferry Business Act, Water-Related Leisure Activities Safety Act, and Act on the Development, Management, etc. of Marinas. These Acts have differences in regulations, in terms of gross tonnage, the age of vessels, crewman, and the liquor traffic. These differences can cause problems such as adjusting the gross tonnage of the vessel by modifying the structures of the facilities, assigning old vessels, sailing without crewmen required for safety, and going against fairness in the liquor traffic in similar businesses. Such differences appeared to be caused by the lack of understanding of leisure boats and the series of new legislation which have been added one by one. It is required to raise the understanding on the characteristics of leisure boats and reflect them in the legislation.

• Journal of Nutrition and Health
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• v.6 no.4
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• pp.55-60
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• 1973

To determine the effects of condiments upon Proteinase Activity, condiments such as welsh onion, garlic, ginger, black pepper, red pepper, mi-won (glutamic acid natrium), sugar, mustard and horse-radish were ground by a homogenizer, and each of them was dosed by 0%, 1%, 5% and 10% into Pancreatin Solution of 0.2% for storage at the temperature of 15 degrees Cels. The Enzyme Solution thus obtained then was measured at a certain interval of time by the Fuld Gross Method, and the following results were obtained. 1) The condiments that kept Proteinase Action of Pancreatin checked below 75% were mustard, horse-radish, red pepper and welsh onion. The centrol power of welsh onion, in particular, became stronger as storage time became longer. 2) The condiments that kept Proteinase Action of Pancreatin checked below 50% were sugar, black pepper and ginger. 3) Mi-won and garlic showed a strong checking powor over Proteinase Action at an early stage of storage, but as time passed, their control power gradually diminished to naught. In short, it may be concluded that ail of the condiments used in this experiment demonstrated their checking power over Proteinase Action.