• The KIPS Transactions:PartA
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• v.13A no.6 s.103
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• pp.555-560
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• 2006

In contrast with the earlier remote education that simply recorded off-line classes, modern remote education emphasizes on offering additional functions that could maximize learning efficiency. Usage of such multimedia information as the texts, graphics, sounds, animations is considered fundamental element in offering the additional functions. This paper designs and implements an encoder/decoder that could accommodate the multimedia information with emphasis on demonstrating execution files. Instructors can demonstrate my type of execution files or application data files, and the remote learners can freely try running the corresponding execution files by themselves. Consequently, a high-level of learning efficiency can be achieved by the proposed encoder/decoder.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.05a
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• pp.173-176
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• 2010

A subscale gas generator was designed and manufactured to understand a reason for increased pressure drop of liquid oxygen injectors observed in a technology demonstration model of a 75 ton-class gas generator. A total of 6 hot-firing tests were successfully performed including experimental conditions of design and off-design points. The hot-firing results showed that discharge coefficients of fuel and liquid oxygen remained constant as the mixture ratio varied at a fixed chamber pressure. At a fixed mixture ratio, it was also found that discharge coefficients of fuel and liquid oxygen was constant as the chamber pressure was increased.

• Journal of the Korea Convergence Society
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• v.13 no.1
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• pp.179-188
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• 2022

This study discovers the general characteristics of B-class Emotional Advertisements and analyses their trend. A content analysis was conducted on 498 advertisements on-aired between 2015 and 2020, which were sampled from the advertisements registered in the TVCF(www.tvcf.co.kr), the largest advertisement web portal in the Republic of Korea. The analysis concludes that the B-class Emotional Advertisements, employed in a wide range of genre, is most incorporated in comedy/exaggeration genres and is on a rising trend due to 2020 COVID-19 Pandemic. Furthermore, it is confirmed that the utilization of B-class emotional advertisement has also increased in domain of non-commercial advertisements, such as Public Service Advertisements, Governmental/Organizational Advertisements, and Corporate Public Relations (PR) Advertisements. The study validates the transformation of the B-class emotional advertisements from a demonstration of an eccentric minority subculture to an epitome of a new and adventurous mainstream culture, successfully serving a central role in both the commercial and non-commercial sectors. Depicting the caricatures of the social, cultural and economic phenomenon and the recent surge of individual's depression, fatigue and pessimism, B-class emotional advertisements provide sympathetic and emotional alleviating ground for people that contributed to its rise.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.05a
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• pp.190-193
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• 2004

Ever since the ideal forming theory has been developed fur process design purposes, application has been limited to sheet forming and, for bulk forming, to two-dimensional steady flow. Here, application for the non-steady case was performed under the plane-strain condition based on the theory previously developed. In the ideal flow, material elements deform following the minimum plastic work path (or mostly proportional true strain path) so that the ideal plane-strain flow can be effectively described using the two-dimensional orthogonal convective coordinate system. Besides kinematics, for a prescribed final part shape, schemes to optimize a preform shape out of a class of initial configurations and also to define the evolution of shapes and boundary tractions were developed. Discussions include the two problematic issues on internal tractions and the non-monotonous straining. For demonstration purposes, numerical calculations were made for a bulk part under forging.

• Proceedings of the KSME Conference
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• 2008.11b
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• pp.3169-3174
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• 2008

Future power plants will be required to adopt some type of carbon capture and storage (CCS) technologies to reduce their CO2 emissions. One of distinguished CCS techniques expected to resolve the green house effect is to apply the oxy-fuel combustion technique to power plant, and a lot of research/demonstration programs have been going on in the world. In this paper, CO2-capturing power plants based on gas turbine and oxy-fuel combustion are investigated over several types of configurations. As a prior step, simulation model for 500 MW-class combined cycle power plant was set and was used as a reference case. The efficiencies of several power plants was compared and the advantages and disadvanteges was investigated.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1788-1790
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• 2005

In this paper, an operating characteristics of a 50 kW gird-connected photovoltaic(PV) power system was analysed from 2000 to 2004. The construction of the PV system includes a 3-phase inverter for grid connection, PV module, distribution box, and data monitoring system. The major results of the demonstration test of the 50 kW class gird-connected PV system showed that efficiency of PV system was 11.13%, and the conversion efficiency of the inverter was 92% at a 50% load.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.110-111
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• 2019

본 논문은 DC 배전 전기 추진 시스템으로 건조된 10톤급 소형 어선을 운항하며 계측한 실험 결과를 제시한다. DC 배전 선박과 모의된 AC 배전 선박을 일반적인 10톤급 소형 어선의 운용 패턴에 따라 운항하였고, 각 경우의 연료소모량을 유량계로 측정하였다. DC 배전 시스템은 가변속으로 인한 엔진의 효율적인 운전과 전기설비 무게 감소로 인한 추진 부하 감소의 효과로 AC 배전 시스템에 비하여 연료사용량이 약 20% 가량 절감된다. 실험 결과, DC 배전 전기 추진 선박을 적용할 시 연간 약 18,500L (22.0%)의 연료가 절감되어 연료비가 매년 약 1400만원 가량 절약될 것으로 예상된다.

• Nonlinear Functional Analysis and Applications
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• v.28 no.2
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• pp.589-599
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• 2023

The object of this study is to introduce a new subclass of univalent analytic functions on the open unit disk. This subclass is created by utilizing univalent analytic functions with negative coefficients. We first explore the specific properties that functions in this subclass must possess before examining their coefficient characterization. By applying this approach, we observe several fascinating features, including coefficient approximations, growth and distortion theorems, extreme points and a demonstration of the radius of starlikeness and convexity for functions belonging to this subclass.

• Journal of The Korean Association For Science Education
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• v.43 no.2
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• pp.87-98
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• 2023

In this study, we investigated the change in science core competency perception of high school students and the reason for change when science inquiry classes were conducted using eight 'skills' of the 2015 revised science curriculum. Fifteen first-year high school students in Jeollanam-do participated in the science inquiry class of this study, and the class was conducted for 20 hours (5 hours a day for four days). The inquiry activities used in the class consisted of four activity stages (research problems, research methods, research results, and conclusions) and each stage was constructed to include at least one 'skill (Problem Recognition, Model Development and Use, Inquiry Design and Performance, Data Collection, Analysis and Interpretation, Mathematical Thinking and Computer Application, Conclusion and Evaluation, Evidence-based Discussion and Demonstration, and Communication)'. As a result of the study, students' perception of the five science core competencies increased statistically significantly at the significance level of 0.01 through inquiry classes and more than 93% of students recognized that their science core competencies improved through the classes. However, since the class of this study was conducted for a small number of students, it is difficult to generalize the effect of the class, and so it is necessary to conduct a quantitative study for many students.

• Journal of The Korean Association of Information Education
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• v.12 no.4
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• pp.375-384
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• 2008

Computer programming has educational effect on improving high-level thinking abilities. However, students initially have to spend too much effort in learning the basic grammar and the usage model of programming languages, which negatively affects their eagerness in learning. To remedy this problem, we propose to apply the Scratch to a Game Developing Programming Class; Scratch is an easy-to-learn and intuitive Educational Programming Language (EPL) that helps improving the Meta-cognition and Self-efficacy of middle school students. Also we used the Demonstration-Practice instruction model with self-questioning method for activating the Meta-cognition. In summary, a game developing programming class using Scratch was shown to significantly improve the Meta-cognition of middle school students. However it was shown to insignificantly improve the Self-efficacy of girl students group.