• Journal of the Korean Society of Propulsion Engineers
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• v.22 no.1
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• pp.52-57
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• 2018

This paper presents the design and cold flow test results of oxidizer-rich preburner injectors for a 9 tonf-class staged combustion engine cycle. Three types of coaxial swirl injectors were designed, and 12 injectors were designed for each type. The diameters of the fuel tangential holes are identical. The diameters of the oxidizer tangential holes were varied to investigate the influence of combustion in the oxidizer-rich preburner according to the momentum ratio of the gas oxidizer generated from combustion in the injector chamber and liquid oxidizer through the cooling channel. It will be verified through a powerpack and combustion test using an oxidizer-rich preburner. In the cold flow test, the fuel flow rate and oxidizer tangential hole flow rate reached the target value based on the designed differential pressure.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.891-891
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• 2002

Currently there are numerous papers in which many new kinds of customizing stereotypes by UML extension mechanism for different application environments such as real-time system, Geographic Information System (GIS) and so on are proposed. However , these stereotypes that represent different type model elements such as class, association, generalization and so on have not yet been seen in one of the most popular visual modeling tool for software development, Rational Rose. Therefore, in this paper, a design of extended iconic stereotype for GNSS application in the UML class diagram and its implementation as a tool of StereotypeCreator for Rational Rose will be presented.

• Journal of Engineering Education Research
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• v.13 no.2
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• pp.16-21
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• 2010

The objective of this study was to evaluate Environmental microbiology (EM) as a basic course for the environmental engineering program of Korea Maritime University which has been accredited by Accreditation Board for Engineering Education of Korea (ABEEK). Evaluation result of the lecture objectives was more than the average (3.5/5.0). The overall score for learning achievement assessment was more than average level of learning achievement (3.4/5.0). Interestingly, engineering design implementation regarding a specific topic as an extensive learning process has proven to be more effective (3.5/5.0). Some of effective class improvement strategies suggested were to encourage students to participate in the class with self-motivation and accountability: preview and review of the lecture, team presentation in English-speaking settings, and submitting project report written in English. In the future class of EM, test and evaluation of application capability of EM and environmental biotechnology (EB) theories to engineering problem solving should be emphasized.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.3
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• pp.73-76
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• 2003

In modern EHV (Extra High Voltage) class GCBs (Gas Circuit Breakers), the interruption capability for SLF (Short Line Fault) is one of the most important aspects of performance required for GCBs. Up to now, the SLF interruption capability of EHV class GCBs was partially assisted by the adoption of capacitors able to decrease the dV/dt of the TRV (Transient Recovery Voltage), particularly the TRV on the line side. This paper describes the technique to increase the SLF interruption capability of EHV class GCBs as well as the procedure to develop capacitorless l70kV 50kA GCB.

• Journal of Information Processing Systems
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• v.15 no.2
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• pp.320-330
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• 2019

This study analyzed changes in sociality and democratic-citizenship among elementary school students in the information class and the science class at the Science Education Institute for the Gifted, who were divided into an experimental group and a control group. The experimental group engaged in the Learning Together (LT) cooperative form of learning for which the remix function of Scratch, an educational programming language, was applied, while the control group was given general instructor-led lessons. Members in the experimental group were able to modify processes during projects through the usage of the remix function, thereby actively participating in the projects and eventually generating team-based results. The post-class t-tests showed a greater degree of improvements in sociality and democratic citizenship for the experimental group that was offered the remix-function-based cooperative learning than the control group. Statistically significant differences were present between two groups particularly in "cooperative spirit" sub-domain of sociality and the "community" and "responsibility" sub-domains of democratic citizenship.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.10a
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• pp.19-24
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• 1995

Most difficulties in inducing high flowability of general strength concrete arise from the segregation of aggregates due to the shortage of cementatious binders. To solve the problem, our research team has concentrated on finding the binders to link a gap between coarse and fine aggregates, under the condition not to influence a concrete strength. As a result of using stone powder or a middle class of aggregate size mostly used for asphalt pavement(Max. dia 13mm), we found that flowability of concrete increased significantly without aggregation and decrease of compressive strength.

• Nonlinear Functional Analysis and Applications
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• v.27 no.3
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• pp.649-662
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• 2022

This paper is concerned with the existence of solutions for a class of 𝚽-Kirchhoff type equations with critical exponent in Orlicz-Sobolev spaces. Our technical approach is based on variational methods.

• Animal Systematics, Evolution and Diversity
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• v.22 no.1
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• pp.57-62
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• 2006

Some scyphomedusae were collected from the coasts of Ilgwang, Jeju Harbour, Yeosu, Yokjido Is. and Munyeodo Is. in Korea from May to Nov. 2004. They were indentified into Pelagia noctiluca Forskal, 1775 and Cyanea nozakii Kishinouye, 1891 of the order Semaeostomeae and Nemopilema nomurai Kishinouye, 1922 of the order Rhizostomeae in the class Scyphozoa. They are new to the Korean fauna.

• Proceedings of the KIEE Conference
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• 1995.07c
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• pp.1034-1038
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• 1995

The purpose of this study is to research and develop $TiS_2$ composite cathode for lithium polymer battery(LPB). $TiS_2$ electrode represent a class of insertion positive electrode used in Li secondary batteries. In this study, we investigated preparation of $TiS_2$ composite cathode and AC impedance response of $TiS_2$ composite/SPE/Li cells as a function of state of charge(SOC) and cycling. The resistance of B type cell using $TiS_2PEO_8LiClO_4PC_5EC_5$ composite cathode was lower than that of A type cell using $TiS_2PEO$ composite cathode. The cell resistance of B type cell is high for the first few percent discharge, decreases for midium discharge and then increases again toward the end of discharge. We believe the magnitude of the cell resistance is dominated by passivation layer impedance and small cathode resistance. AC impedance results indicate that the cell internal resistance increase with cycling, and this is attributed to change of passivation layer impedance with cycling. The passivation layer resistance($R_f$) of B type cell decreases for the 2nd cycling and then increases again with cycling. Redox coulombic efficiency of B type cell was about 141% at 1st cycle and 100% at 12th cycle. Also, $TiS_2$ specific capacity was 115 mAh/g at 12 cycle.

• Journal of Fashion Business
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• v.24 no.5
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• pp.125-139
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• 2020

The fashion industry that perceived the severity of environmental pollution, has sought various methods of sustainable fashion. However, most of the businesses paid attention to the development of materials using industrial waste, or vegan material. Thus, this study aims to present the methods for improvement in creativity for inversely developing the design from patterns and present new approaches by applying the contrarian development of proto to class under the limited condition of material concerning general design, selection of material, and production of sample. In the case of three student teams enrolled in the first semester of the second year, the fabric and used clothing donated by industry were used as material. The whole cut for cutting a single fabric in connected state, and Zero Wastes Design within a rectangular frame of fabric, upcycling of used clothes, and cutting out of Geometric Form are suggested. The team(A) produced a zero-wastes coat and whole-cut Pancho that could be variously represented. The team(B) produced two kinds of asymmetric dress by utilizing used check-patterned shirts through upcycling. The team(C) utilized the fabric in geometric forms such as rectangle, trapezoid, and atypical figure by drawing design within donated fabrics. The items were a dress, blouse, and skirt. Consequently, an opportunity for both academia and industry to present more concrete methods for sustainable fashion and deeply perceive the sustainable fashion is presented along with novel methods for creation by carrying out the composition of pattern and design at the same time.