• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.1
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• pp.52-60
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• 2013

Ejector-diffuser system makes use of high-pressure primary stream to entrain the low-pressure secondary stream through pure shear action between two streams. In general, the flow field in the ejector-diffuser system is highly complicated due to turbulent mixing, compressibility effects. A fatal drawback of the ejector system is in its low efficiency. Many works have been done to improve the performance of the ejector system, but not yet satisfactory. In the present study, a mixing guide vane was installed at the inlet of the secondary stream for the purpose of the performance improvement of the ejector system. A CFD method has been applied to simulate the supersonic flows inside the ejector-diffuser system. The present results obtained were validated with existing experimental data. The mixing guide vane effects are discussed in terms of the entrainment ratio, total pressure loss as well as pressure recovery.

• The Korean Journal of Food And Nutrition
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• v.27 no.5
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• pp.771-784
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• 2014

The purpose of this study was to estimate the relationships between dietary factors and the stress perception levels of College students. A survey was conducted in June, 2010, targeting 332 college students in Gwangju. General environmental factors, stress perception levels, dietary behaviors, and dietary action guide performance of the subjects were evaluated by questionnaire, and food intakes was determined by the 24-hour recall method. The results are summarized as follows.: The score of frequency experiencing was $45.1{\pm}16.9$ for male students, and $47.0{\pm}16.7$ for female students. The importance scores were $50.8{\pm}18.5$ for males, and $53.3{\pm}18.7$ for females. The total score for dietary action guide performance was $39.6{\pm}7.2$ for males and $40.6{\pm}6.5$ for females. Nutrient intake levels were evaluated based on dietary reference intake (DRI), revealing energy intakes to be 68.5% EER in males and 73.9% in females. The mean intakes of nutrient were 54.2% RI for calcium, 73.6% RI for riboflavin, and 51.2% RI for vitamin C but 203.6% AI for sodium, which indicates an imbalance in nutrient intake. Analysis of the correlations between stress perception levels and dietary factors, scholarship achievements, financial problems, future problems, value senses, and family relationships revealed significant correlations with general environment factors, dietary behaviors, Dietary action guide performance, and nutrient intakes (p<0.05). The higher the stress perception levels of the students, the higher the energy, coffee and alcohol intake, which predicts that appropriate stress control in college students will lead to better dietary habits. It is expected that the results above will be used as basic data for the development of proper nutrition education programs and stress control strategies.

• Journal of Korean Elementary Science Education
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• v.30 no.4
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• pp.535-552
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• 2011

The purpose of this study was to investigate elementary school teachers' conceptions on the general remarks (GR) in the new science teacher's guide, the teachers' conceptions on inservice training program of the GR, and their opinions of improvement on the GR. Also, the teachers' utilization of the GR was examined. The participants were 152 elementary school teachers who were teaching grade 3~6. A questionnaire was used to collect data. The results of this study are as follows; First, at least 13.2~17.1% of the teachers did not have specific conception of the purpose of the GR, and more than 90% of the teachers expressed that the GR is necessary in the teachers' guide. Second, about 60% of the teachers responded that the training program on the GR is necessary, and when the program is open, their most favorite agency and speaker were a provincial education office and a textbook developer(or author), respectively. Their most favorite time and period of the training program were the vacation and 15~30 hours, respectively. Third, the mean values on the frequency of use were lower than 3 point of the five-point Likert scale at both the GR for grade 3~4 and the GR for grade 5~6, and the teachers' main use of the GR was the planning a science lesson for an open class. Fourth, the teachers suggested various opinions and there was difference between the opinions about the GR for grade 3~4 and the opinions about the GR for grade 5~6.

• Journal of the Institute of Convergence Signal Processing
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• v.17 no.1
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• pp.40-45
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• 2016

In accordance with the digital broadcast data converted, the number of the service provider, and content channel for interaction with the viewer has increased exponentially. Electronic program guide in such a multi-channel time(Electronic Program Guide, EPG) is an essential requirement, and also from day to day EPG generation technique according to the user's requirements. But the current situation is getting EPG to viewers outside for reasons such as absence, lack of accurate information, organizing techniques utilized lack of standard systems. In this article, we describe the State and EPG solution to the problem of these terrestrial stations. This, the EPG information and the actual broadcast time of the terrestrial channel 6 using a ground wave receiving method for a direct comparison was studied the problems and the average error of the current start. Also this research perform to enhance accuracy of EPG information.

• Journal of Korean Home Economics Education Association
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• v.9 no.2
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• pp.115-130
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• 1997

The purposes of this study are：(1) to analyze the learning content & subjects on the area of clothing and textiles in Home Economics for Young Men： A Teaching Guide, (2) to compare it with the learning content & subjects on the area of clothing and textiles in Home Economics teaching guides in the middle school in Korea, (3) to provide preliminary data for developing the learning content & learning method on clothing and textiles education for middle school students. To implement these proposals, Home Economics for young Men： A Teaching Guide in U.S.A and 6 Home Economics teaching guides for the middle school in Korea are reviewed and analyzed. The research findings were as follows： 1. Home Economics for Young Men is characterized as including： (1) interesting learning contents for girls and boys in the middle school, (2) learning contents for helping students to work on their own initiative (3) learning contents related to actual life, (4) practical consumer education content related to clothing and textiles area, (5) learning contents for developing originality, (6) learning contents related to vocational education. 2. The subjects in Home Economics for Young Men give careful considerations especially on how to learn. They are based on the idea that middle school students have to learn and to solve the subject by themselves. 3. Learning contents on Home Economics teaching guides for middle school in Korea are different from learning contents in Home Economics for Young Men in the subject & the form of description, the subject matter of practice in clothing area, the standpoint of description on clothing matters. The subjects in Home Economics teaching guides for middle school in Korea don’s give careful consideration on how to learn. There are little idea that middle school students have to learn and to solve the subject by themselves.

• Journal of the Korean Society of Propulsion Engineers
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• v.16 no.4
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• pp.1-8
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• 2012

In this study, numerical method, stage stacking method based on the result of numerical method and scaled stage stacking method have been applied to predict the performance of a multi-stage axial compressor with inlet guide vane. The results obtained through three different methods for off-design conditions were compared with performance test data. And the effect the angle of variable inlet guide vane was also investigated. The three-dimensional numerical simulation has been performed by using flow analysis program, $FLUENT^{TM}$ 6.3 and the performance prediction based on the stage stacking method has been performed with compressor analysis code from NASA.

• Plant Journal
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• v.18 no.2
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• pp.32-40
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• 2022

In this study, we investigated the operation data of combined heat and power in accordance with the change of the inlet guide vane with partial load. The partial load 80% could close the inlet guide vane up to 24%, and the exhaust gas temperature could be increased by 52℃. The partial load 90% could close the inlet guide vane up to 12%, and the exhaust gas temperature could be increased by 23℃. At 80% of partial load with the thermal load tracking mode, the output could be increased up to 5.68 MW, the combined cycle efficiency increased by 0.73%, and the combined heat and power efficiency increased by 1.81%. At 90% of the partial load, the output could be increased up to 2.55 MW, the combined cycle efficiency increased by 0.32%, and the combined heat and power efficiency increased by 0.72%.

• Design Convergence Study
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• v.14 no.4
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• pp.169-180
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• 2015

This research is to analyze the status of menu guides provided to inpatients in Korean hospitals, analyze the problem of delivering information, and propose improvement plans through information visualization as a part of improving service for inpatients. The nutrition department in hospitals were directly visited, data were collected, and the types and contents of menu guides were analyzed. Then, problems were found by focusing on whether there is an effective delivery of information, in terms of information visualization aspects. The menu provided to inpatients in Korean hospitals are divided into general, optional, and therapeutic menu depending on patients' conditions, and the menu guide is largely divided into a general guide and optional guide. The information covers menu, origin of ingredients, guide, withdrawal time, etc. However, there is no categorization according to the contents or importance of information, thus creating inefficient problems for patients to acquire information. The problem of menu guides is that they do not deliver information properly due to disorganized information. In order to improve this, information should be categorized and visualized according to its contents and importance for enhancing readability, which will then be able to provide menu guides that can deliver information more efficiently to patients.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.942-944
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• 1993

This paper treats of the recent trends in the development, of the Magnetically levitated vehicle(Maglev) and the propulsion system of the Maglev in the world. Consequently, the material data for the guide post in the research and formulation of development policy are prevented.

• Journal of IKEEE
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• v.19 no.3
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• pp.415-423
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• 2015

The DO-178C guide, which is referenced as the software development guide when a certification of the airworthiness in the commercial airplane is acquired by FAA in US, is recently referenced for the local military aircraft airworthiness. This indicates that when the auditor of the military aircraft airworthiness looks over the software development documents, the auditor reviews if all of the documents are verified in accordance with the DO-178C guide. However, when we developed the military aircraft intercom, We developed its control software in accordance with the CMMI level 3, since there were no requirements for the compliance of the DO-178C guide. Therefore, When we consider the airworthiness of this intercomm system, The analysis for how much the software development based on the CMMI level 3 is different from the DO-178C guide is needed to prepare the essential software documents additionally. Thus, This study analyzes the differences between CMMI level 3 and DO-178C guide and provides that which data on the CMMI level 3 is necessary for the compliance of the aircraft airworthiness comparing with the DO-178C. The analyzed result can be applied at the software development of the other military aircraft avionics equipment based on the CMMI model environment considering the compliance of the military aircraft airworthiness.