• Korean journal of food and cookery science
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• v.16 no.2
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• pp.112-120
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• 2000

The purpose of this study was to examine the needs of high school students on foodservice. A survey from 8 high school foodservice operations in Seoul was undertaken and detailed information was collected from 538 high school students. Completed questionnaires were received from 3 self-operated and 5 contracted school foodservice operations. Statistical analyses were performed by SPSS including descriptive analysis and t-test. The 49.8% of the respondent students were male and 50.2% female. The whole students assessed the importance and performance of school foodservice as 4.18 and 2.83 out of 5 respectively, which suggests that the school foodservice needs to be improved. The Importance-Performance Analysis(IPA) used for obtaining information on high school foodservice management suggested that foodservice attributes with fair to poor performance but with high importance were sanitation of food, service of foodservice personnel, dealing with complaints and the reflection of students'opinion in menu.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.169-170
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• 2006

Advanced melting technology is now being employed in the manufacture of stainless steel powders. The new process currently includes electric arc furnace (EAF) technology in concert with Argon Oxygen Decarburization (AOD), High Performance Atomizing (HPA) and hydrogen annealing. The new high performance-processing route has allowed the more consistent production of existing products, and has allowed enhanced properties, such as improved green strength and green density. This paper will review these processing changes along with the potential new products that are being developed utilizing this technology. These include high strength stainless steels such as duplex and dual phase as well as stainless steel powders used in high temperature applications such as diesel filters and fuel cells.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.2
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• pp.143-152
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• 2006

High performance concrete(HPC) has been widely used in high-rise building. The HPC has several benefits including high strength, high fluidity and high durability. However, spalling is susceptible to occur in HPC and HPC also tends to be deteriorated in the side of fire resistance performance at fire. This paper investigated the spalling prevention of high performance RC column. Control concrete showed severe failure and a case of concrete with fire enduring spraying material exhibited more severe spalling failure than even control concrete. In addition, concrete with fire enduring paint reported the most favorable spalling resistance effect for preventing spall, compared with other concrete covered with finishing materials, such as fire enduring spraying material, gypsum board, marble board and fire enduring PC board. Meanwhile, concrete adding 0.1% of PP fiber demonstrated spalling resistance performance after 3hours load bearing test.

• International Journal of Fluid Machinery and Systems
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• v.6 no.1
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• pp.25-32
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• 2013

Data centers have been built with spread of cloud computing. Further, electric power consumption of it is growing rapidly. High power cooling small-sized fans; high pressure and large flow rate small-sized fan, are used for servers in the data centers and there is a strong demand to increase power of it because of increase of quantity of heat from the servers. Contra-rotating rotors have been adopted for some of high power cooling fans to meet the demand for high power. There is a limitation of space for servers and geometrical restriction for cooling fans because spokes to support fan motors, electrical power cables and so on should be installed in the cooling fans. It is important to clarify complicated internal flow condition and influence of a geometric shape of the cooling fans on performance to achieve high performance of the cooling fans. In the present paper, the performance and the flow condition of the high power contra-rotating small-sized axial fan with a 40mm square casing are shown by experimental and numerical results. Furthermore, influence of the geometrical shape of the small-sized cooling fan on the internal flow condition is clarified and design guideline to improve the performance is discussed.

• Journal of Fisheries and Marine Sciences Education
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• v.20 no.3
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• pp.358-368
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• 2008

The purpose of this study is to gather background data of teacher's performance of the fisheries and shipping industries high schools. This data will provide direction for advancing teacher's performance of the fisheries and shipping business high school,s by investigating and analyzing variables related to teacher's performance. This study focused on the opinions of thirty teachers within the fisheries and shipping business high schools. The conclusions of the study were as follows: First, teachers continually seek goal achievement, rewarding jobs, and a feeling of self-worth. However, it was found that male teachers have stronger task performing ability and form stronger relationships with their partners than female teachers. Second, it was shown that teachers have a much higher percentage of ability to teach. Particularly, male teachers are generally higher than female teacher. Third, it was shown that teachers have a much higher percentage of ability to teach, but it is required that they both get equal participation opportunity as there is a little difference between male teachers and female teachers. Fourth, it was found teachers exhibited a lower percentage rate of ability to manage activities, and required further development of programs for expansion of professionalism of this field.

• Proceedings of the IEEK Conference
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• 2000.11a
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• pp.113-116
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• 2000

The effect due to group delay and non linear characteristics in high speed data satellite channel was represented in this paper. Based on the modeling of group delay and non linear characteristics the performance was analyzed in ka band satellite channel. The group delay and non-linear characteristics in high speed data transmission severely affect the system performance. The more Eb/No is required to satisfy the required system performance. The optimum operating points of HDR satellite transmission system are implemented by considering analyzed results for channel characteristics

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.4
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• pp.740-742
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• 2010

This paper investigates a high-performance strategy for speed sensorless control of a permanent magnet synchronous motor. Two speed sensorless controls using back-EMF and reactive power are analyzed in this paper, and these two speed estimations are appropriately applied according to the steady and transient states for a high-performance sensorless control. The proposed sensorless control algorithm has a better performance compared to the conventional control algorithms.

• Advances in concrete construction
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• v.10 no.5
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• pp.443-454
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• 2020

In recent years, many studies have been done on the performance of concrete containing glass powder (GP). For the purpose of widespread use of GP in concrete mixes, a knowledge of the performance of such a mixture after a fire is essential for the perspective of structural use. This research work was carried out to evaluate the performance of High Performance Concrete (HPC) made with GP after being exposed to elevated temperature. The studied mixtures include partial replacement of cement by GP with up to 30%. The mechanical performance and structural alterations were assessed after high temperature treatment from 200℃ to 800℃. The mechanical performance was evaluated by testing the specimens to the compressive and tensile strength. In addition, the mass loss and the porosity were measured to notice the structural alterations. Changes in microstructure due to temperature was also investigated by the X-ray diffraction (XRD) and thermal gravimetric analyses (TGA) as well as porosity adsorption tests. The results of the concrete strength tests showed a slight difference in compressive strength and the same tensile strength performance when replacing a part of the cement by GP. However, after high temperature exposition, concrete with GP showed better performance than the reference concrete for temperature below 600℃. But, after heating at 800℃, the strength of the concrete with GP drop slightly more than reference concrete. This is accompanied by an important increase in mass loss and water porosity. After the microstructure analysis, no important changes happened differently for concrete with GP at high temperature except a new calcium silica form appears after the 800℃ heating.

• Journal of the Korean Recycled Construction Resources Institute
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• v.8 no.3
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• pp.269-275
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• 2020

In this study, flexural tests of precast concrete panels according to the thickness of cross-sectional and the with or not of reinforcement were carried out in order to develop and assess of a lightweight precast concrete panel using ultra high performance concrete. For the test, four panels were fabricated, and consisted of one normal concrete panel and three ultra high performance concrete panels. As a test result, it was found that the plain precast panel using ultra high performance concrete had a lower flexural performance than the reinforced normal concrete panel, regardless of the cross-sectional size. The flexural performance of the hollow-sectional precast panel applying ultra high performance concrete, is improved by 150% compared to that of the reinforced normal concrete panel. That is, through additional performance verification and optimization of the cross-sectional design of the panel, the ultra high performance concrete precast panel can be made lighter. Also, the practical use of lightweight precast panels with ultra high performance concrete can be available through evaluation on shear, joint connection and anchoring, etc.

• Journal of the Korean Society of School Health
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• v.16 no.2
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• pp.125-134
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• 2003

Purposes of this study were 1) to identify the level of role expectation and role performance for school health educators as elementary school students recognize and to compare them, and 2) to examine differences in the role expectation and performance by characteristics of students and educators. Subjects of the study were 1,433 6th grade students at 37 elementary schools in Busan. The data were collected by a structured self-administered questionnaire, measuring role expectation and performance that students recognize. The data were analyzed with descriptive statistics, t-test, and ANOVA by SPSS program. The results were summarized as follows. 1. Students' level of recognizing the role expectation was high(M=4.08) and level of the role performance was moderate to high(M=3.50) within range of 1 to 5. The students recognized role expectation greater than role performance. 2. The students' point of view for role expectation and performance for school health educators were related to several characteristics of students and school health educators. Students' levels of recognizing the role expectation and performance were higher when students were male, healthy, their academic performance was high, their level of satisfaction with their school life was high, and their level of satisfaction with using school health office was high. With characteristics of School health educators, students' level of appreciating the role expectation was higher when educators were of an older age and had a long career, and when they were fairly satisfied with their job as an educator. Students' level of recognizing the role performance was higher when educators were of a younger age, and had a small number of students at school. This indicates that there exists role conflict on students and implies that the conflict needs to be mediated, and desirable solutions to address the conflict need to be developed by school health educators.