• 한국전산유체공학회지
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• 제20권4호
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• pp.14-20
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• 2015

Without electirc power to cool down the hot reactor core, passive systems utilizing natural circulation are becoming a big specialty of recent neculear systems after the severe accident in Fukusima. When we consider the natural circulation in a pool, thermal mixing phenomena may start from single phase circulation and can continue to two phase condition. Since the CUPID code, which has been developed for two-phase flow analysis, can deal with the phase transition phenomena, the CUPID would be pertinent to natural convection problems in single- and two-phase conditions. Thus, the CUPID should be validated against single- and two-phase natural circulation phenomena. For the first step of the validation process, this study is focused on the validation of single-phase natural circulation. Moreover, the CUPID code solves the fluid properties by the relationship to pressure and temperature from the steam table considering non-condensable gas effects, so that the effects from variable properties are included. Simple square thermal cavity problems are tested for laminar and turbulent conditions against numerical and experimental data. Throughout the investigation, it is found that the variable properties can affect the flow field in laminar condition, but the effect becomes weak in turbulence condition, and the CUPID code implementing steam table is capable of analyzing single phase natural circualtion phenomena.

• 벤처창업연구
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• 제6권3호
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• pp.43-59
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• 2011

최근 시장환경의 변화와 음악을 전공하는 음악학도가 많아지면서 음악학원이 위기를 맞고 있다. 무엇보다도 결정적인 이유는 음악경영의 경쟁자가 늘고 있고, 출산율 감소로 학원생이 줄어들어 학원 시장의 규모가 잠재적으로 축소되고 있다. 이에 따라 음악학원도 경영의 마인드가 필요하다. 본 연구는 음악학원의 운영의 성과인 경영성과에 영향을 미치는 요인을 규명하고자 한다. 본 연구의 내용은 3가지 영역으로 창업의 성공요인, 창업동기, 경영성과와 관련된 관련 내용을 살펴보고, 음악학원을 창업한 원장들을 대상으로 설문지를 통해서 경영성과에 영향을 미치는 요인을 분석하였다. 분석결과 경영성과에는 다양한 변수에 의해서 유의미한 영향을 미치는 것으로 나타났다. 따라서 음악학원도 벤처 경영의 접근방식이 필요하며, 음악학원, 거주환경, 상황적인 각각의 환경에 적합한 마케팅 전략이 필요하다.

• Journal of Astronomy and Space Sciences
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• 제29권4호
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• pp.329-336
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• 2012

Korea Astronomy and Space Science Institute researchers have installed and operated magnetometers at Bohyunsan Observatory to measure the Earth's magnetic field variations in South Korea. In 2007, we installed a fluxgate magnetometer (RFP-523C) to measure H, D, and Z components of the geomagnetic field. In addition, in 2009, we installed a Overhauser proton sensor to measure the absolute total magnetic field F and a three-axis magneto-impedance sensor for spectrum analysis. Currently three types of magnetometer data have been accumulated. In this paper, we use the H, D, Z components of fluxgate magnetometer data to investigate the characteristics of mid-latitude geomagnetic field variation. To remove the temporary changes in Earth's geomagnetic filed by space weather, we use the international quiet days' data only. In other words, we performed a superposed epoch analysis using five days per each month during 2008-2011. We find that daily variations of H, D, and Z shows similar tendency compared to previous results using all days. That is, H, D, Z all three components' quiet intervals terminate near the sunrise and shows maximum 2-3 hours after the culmination and the quiet interval start from near the sunset. Seasonal variations show similar dependences to the Sun. As it becomes hot season, the geomagnetic field variation's amplitude becomes large and the quiet interval becomes shortened. It is well-known that these variations are effects of Sq current system in the Earth's atmosphere. We confirm that the typical mid-latitude geomagnetic field variations due to the Sq current system by excluding all possible association with the space weather.

• 산업경영시스템학회지
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• 제41권1호
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• pp.128-139
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• 2018

As The Fourth Industrial Revolution and Intelligent Information Age came into full-scale, the policy of open government data has become a hot topic for each country. The United States, the United Kingdom, and other countries are shifting policy direction to "creating value" of open government data. Also, in the age of the digital economy where the data market is soaring, open government data is gradually being recognized as a new raw material for new business and start-ups. In addition, Korea ranked first in the OECD open government data evaluation twice in a row, and was highly evaluated in the international evaluation. However, domestic firms are still lacking in qualitative openness of government data, data is dispersed among institutions, lack of public-private data linkage, and development of app-oriented development. This study attempts to analyze major national policies for the creation of a data ecosystem that considers data lifecycle, from production to storage, distribution and utilization of data. First, the target countries were the leading public data countries among the OGP member countries, the USA, the UK, Australia and Canada. The results of this study are as follows. As a result of analyzing the results and comparing Korea's policies, it was concluded that most of Korea is superior in open government data policy. However, improvement of data quality, development of open data portal as an open platform, support for finding various users including apps and web development companies, and cultivation of open government data utilizing personnel are analyzed as policy issues. In addition, the direction of policy for the balanced ecosystem of Korea is presented together.

• 한방안이비인후피부과학회지
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• 제14권2호
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• pp.207-223
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• 2001

The Wonyenaejang is equivalent to the (senile)cataract in western medicine. The word cataract is used to describe the natural lens that has turned cloudy. As the natural lens of the eye becomes cloudy, it does not allow light to pass through it. Cataracts usually start as a slight cloudiness that progressively grows more opaque. As the cataract becomes more mature(increasingly opaque and dense), the retina receives less and less light. The light that does reach the retina becomes increasingly blurred and distorted. This causes gradual impairment of vision. If left untreated, cataracts can cause needless blindness. Although there are many kinds of cataracts, a senile cataract is the most common one. We chose the oriental medicine textbooks and the oriental medicine journals that were dealing with the symptoms, etiology, and internal/external treatments. The results were as follows : 1. The main causes of this disease are weak liver and kidney, burning up of the wind and heat in the liver and gall, weak spleen and stomach. 2. As the internal treatment of the Cataract, Geegukjihwangtang is mostly prescribed. 3. As the external treatment of the Cataract, (l) In the field of medicine for external application is commonly prescribed (2) In the field of drug action, frequently used treatments are as follows. emission of the evil, alleviation of fever, removal of lump of blood, and the medicine for external applications. (3) In the field of four Qi, cold medicine is commonly prescribed. (4) In the field of five tastes, bitter/hot/sweet mdicine are commonly prescribed. (5) In the field of toxicity, non-togic medicine is commonly prescribed. (6) In the field of channel distribution, most of the medicine belong to liver channel.

• World Technopolis Review
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• 제1권4호
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• pp.276-286
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• 2013

"Federal investments into the future of a region" - pushing economy in the right direction or throwing tax money into a black hole? Hot-headed contentions keep circulating within politics and economy discussing the effect of technology centers and their sustainability within a region. Start-up support and technological infrastructure with the auxiliary service of well developed sector-oriented clusters as a fertile soil for successful networks are an undeniable advantage of well organised technology centers. Sceptic contemporaries still hold against that in order to implement such a center millions of federal funds for infrastructure and operation are invested. What output of this tax money is verifiable in the long run? The case of Dortmund provides substantial food for this necessary and relevant discussion. Now, after 27 years of history of the TechnologieZentrumDortmund, TZDO for short, a positive balance can be drawn. This is not just a matter of personal belief and stance. Fortunately, a recent study on the economic effects of the TZDO on the whole region was performed by the Center of Applied Economy Research M$\ddot{u}$nster, Germany (Gundel and Luttmann 2008). The result is clear and measurable: the TZDO has shown to be of great impact on the positive development of a whole region. This paper presents an account of the approach of the TechnologieZentrumDortmund and its current strategy and mode of operation to reach an utmost of effectiveness of personal and pecuniary input in establishing economic success for the region of Dortmund. An immense change of minds, employment opportunities and a massive structural change of the whole region were some of the ambitious aims that had to be reached and that are achieved to a large extent.

• 식품과학과 산업
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• 제49권4호
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• pp.40-63
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• 2016

John Glenn, America's first man to eat anything in the near-weightless environment of Earth orbit, found the task of eating fairly easy. With improved packaging came improved food quality and menus. By the time of the Apollo Program, the quality and variety of food increased even further. Apollo astronauts were the first to have hot water, which made rehydrating foods easier and improved the food's taste. Thermostabilized pouches were also introduced on Apollo. The task of eating in space got a big boost in Skylab. It also had a food freezer and refrigerator a convenience offered by no other vehicle before or since. Two different food systems will be used for future long-duration missions to other planets, one for traveling to and from the distant body and one for use on the surface of the moon or Mars. The transit food system will be similar to the space station food system with the exception that products with three-to five-year shelf lives will be needed. Thus, this part of the trip will be similar to what occurs aboard space missions now. The surface food system, be it lunar or planetary, will be quite different. It will be similar to a vegetarian diet that someone could cook on Earth. Once crew members arrive on the surface and establish living quarters, they can start growing crops. Once the crops are processed into edible ingredients, cooking will be done in the spacecraft's galley to make the food items. Disposal of used food packaging will be an issue since there will be no Progress vehicles to send off and incinerate into the Earth's atmosphere. Packaging materials will be used that have less mass but sufficient barrier properties for oxygen and water to maintain shelf life as those now in use.

• 대한한방내과학회지
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• 제43권2호
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• pp.237-243
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• 2022

Objective: The purpose of this study is to report the clinical treatment of a nighttime sensation of heat on the palms and soles of the feet of a 71-year-old female patient using Sammulhwanggeum-tang. Methods: Sammulhwanggeum-tang was administered for 19 days to reduce the patient's symptoms, which were assessed using a visual analog scale (VAS) and by duration. Results: The heat sensation began to improve after four days and continued to do so for the subsequent 15 days. From May 12, X to May 30, X, the degree of subjective symptoms decreased from a VAS score of 10 before treatment to 0 after treatment, and their daily duration decreased from 10 to 0 hours. In addition, considering that the duration of the patient's symptoms was about 30 days, the duration of the symptoms decreased to 17 days, including the period before the start of treatment. Conclusion: This clinical study suggests that Sammulhwanggeum-tang might be effective in resolving the sensation of heat on the palms and soles of the feet at night.

• Tribology and Lubricants
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• 제40권3호
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• pp.103-110
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• 2024

Gas foil thrust bearings (GFTBs) are oil-free self-acting hydrodynamic bearings that support axial loads with a low friction during airborne operation. They need solid lubricants to reduce dry-friction between the runner and top foil and minimize local wears on their surfaces during start-up and shutdown processes. In this study, we evaluate the lift-off speeds and load capacity performance of a GFTB with Polytetrafluoroethylene (PTFE) surface coating by measuring drag torques during a series of experimental tests at increasing ambient temperatures of 25, 75 and 110℃. An electric heat gun provides hot air to the test GFTB operating in the closed booth to increase the ambient temperature. Test results show that the increasing ambient temperature delays the lift-off speed and decreases the load capacity of the test GFTB. An early developed prediction tool well predicts the measured drag torques at 60 krpm. After all tests, post inspections of the surface coating of the top foil are conducted. Scanning electron microscope (SEM) images imply that abrasive wear and oxidation wear are dominant during the tests at 25℃ and 110℃, respectively. A quantitative energy dispersive spectroscopy (EDS) microanalysis reveals that the weight percentages of carbon, oxygen, and nitrogen decrease, while that of fluorine increases significantly during the highest-temperature tests. The study demonstrates that the increasing ambient temperature noticeably deteriorates the static performances and degrades the surface coating of the test GFTB.

• Asian-Australasian Journal of Animal Sciences
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• 제21권5호
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• pp.685-691
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• 2008

An experiment was conducted to determine the effect of dietary copper (Cu) on performance, carcass characteristics and lipid metabolism in lambs. Fifty DorperMongolia wether lambs (approximately 3 month of age; 23.80.6 kg of body weight) were housed in individual pens and were assigned randomly to one of five treatments. Treatments consisted of 1) control (no supplemental Cu), 2) 10 mg Cu/kg DM from Cu-lysine, 3) 20 mg Cu/kg DM from Cu-lysine, 4) 10 mg Cu/kg DM from tribasic copper chloride (Cu2(OH)3Cl; TBCC), 5) 20 mg Cu/kg DM from tribasic copper chloride. The Cu concentration was 6.74 mg/kg DM in the basal diet. Body weight was measured on two consecutive days at the start and the end of the 60-day experimental period. Blood samples were collected and then the lambs were slaughtered on d 60. Performance was not affected (p>0.05) by dietary Cu treatment. Cu-supplemented and control lambs had similar hot carcass weight, dressing percentage and longissimus muscle area, but Cu supplementation, regardless of source and level, reduced (p<0.01) 12th rib backfat and kidney fat in lambs. Plasma tumor necrosis factor-alpha (TNF-) and serum triglyceride concentrations were increased (p<0.05), total cholesterol concentrations were decreased (p<0.05) and nonesterified fatty acids (NEFA) concentrations tended to be increased (p<0.07) by Cu supplementation. However, Serum concentrations of HDL-cholesterol and LDL-cholesterol were not affected (p>0.05) by dietary treatment. Fatty acid profile of longissimus muscle was similar across treatments. These results indicate that Cu-lysine and TBCC are of similar availability in lambs. Cu supplementation given to DorperMongolia wether lambs altered lipid metabolism. The reduction in backfat depth may be due to copper altering TNF- metabolism in lambs. Supplementation of 10 or 20 mg Cu/kg DM showed similar effects on lipid metabolism in lambs.