• 한국정보통신학회논문지
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• 제14권12호
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• pp.2707-2715
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• 2010

본 논문에서는 MVC 패턴에 기반한 클래스 다이어그램 저작도구의 설계와 구현을 제시하고자 한다. 클래스 다이어그램 저작도구의 설계는 ClassInformation, ScreenDisplay, ToolManager에 대한 정의를 하고 구조를 기술한다. ClassInformation은 다이어그램의 정보를 가공하거나 처리하는 부분을 담당한다. ScreenDisplay는 저작도구의 화면을 구성하기 위해서 GUI를 담당한다. ToolManager는 저작도구의 입출력 처리위해 이벤트 처리를 담당한다. MVC 패턴을 바탕으로 저작도구의 ClassInformation, ScreenDisplay, ToolManager는 각각의 역할이 독립적으로 나눠져 있고, 결합도를 낮추기 때문에 새로운 기능 추가에 유연하게 대처한다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 ITC-CSCC -2
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• pp.941-944
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• 2000

This paper proposes, for the first time, the design of class I pull-push power amplifier. With the new design, the output power is increased by four times when compared to conventional single-end class I connection amplifier with the same supply voltage. The performance of the proposed amplifier is verified by with a 100-kHz power amplifier constructed using general-purpose NPN transistors.

• 공학교육연구
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• 제24권2호
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• pp.51-60
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• 2021

Although more than 15 years have passed since the introductory design courses were opened due to the introduction of engineering education certification in the civil engineering field, these courses have been operated somewhat unsatisfactorily compared to their importance as an introductory course for engineering design. This is partially because the quality of classes is affected by the instructor's individual ability due to the fact that a standard training plan for these courses has not been established so far. Therefore, in this paper, we try to present a reference model for the introductory design course by introducing a class operation case established through continuous improvement process over the last 10 years at Chungbuk National University. This case aims to cultivate students' problem solving and system design skills by carrying out projects to develop egg drop and wood bridge systems based on creative problem solving methodologies. As a result of a questionnaire survey conducted after the class, we found that students' problem solving and system design capabilities were improved significantly and there was a meaningful increase in level of interest and attention in civil engineering by taking this class.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.87-90
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• 2005

High-efficiency switched-mode circuits such as the class-E amplifier are well-known in the MHz frequency range. The class-E amplifier is a type of switching mode amplifier offering very high efficiency approaching 100%. In this paper of the class-E amplifier by using pHEMT device, the design has been done theoretically and experimentally, with simulation by using the harmonic balance method using circuit simulator. The amplifier using microstrip circuit and the pHEMT demonstrate 66% power-added- efficiency (PAE) at 2.4GHz with 17.6dBm of output power.

• Journal of electromagnetic engineering and science
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• 제16권1호
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• pp.52-56
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• 2016

This paper suggests a class-F power amplifier with split open-end stubs to provide a broadband high-efficiency operation. These stubs are designed to have wide bandwidth by splitting wide open-end stubs into narrower stubs connected in shunt in an output matching network for class-F operation. In contrast to conventional wideband class-F designs, which theoretically need a large number of matching lines, this method requires fewer transmission lines, resulting in a compact circuit implementation. In addition, the open-end stubs are designed with slant ends to achieve additional wide bandwidth. To verify the suggested design, a 10-W class-F power amplifier operating at 1.7 GHz was implemented using a commercial GaN transistor. The measurement results showed a peak drain efficiency of 82.1% and 750 MHz of bandwidth for an efficiency higher than 63%. Additionally, the maximum output power was 14.45 W at 1.7 GHz.

• 공학교육연구
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• 제18권2호
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• pp.77-88
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• 2015

Recently, there has been an increasing interest in 'Flipped Learning,' an IT-based learner-centered teaching-learning method corresponding to meet the paradigm of the future education. For smooth Flipped Learning, there are three steps in total: a pre-class should precede; then, in the structure of classes in the classroom, in-class learning among peer learners should be done; and lastly, the operation of a post-class should be done. For successful Flipped Learning, class elements in each step should be designed with a time difference, interconnected so as to achieve a single educational objective. However, it was found that there was a limitation in that the teaching-learning model of the preceding Flipped Learning consisted of the order of analysis, design, development, implementation and evaluation as general procedures, so it would not sufficiently consider the situations of Flipped Learning only. On this background, this thesis proposes a differentiated Flipped Learning model for mastery learning in a subject of an institute of technology as a model of systematic instructional design and presents a case of a class applied to an actual subject of computer engineering.

• Structural Monitoring and Maintenance
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• 제9권1호
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• pp.43-57
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• 2022

One of the instances which demand structural engineer's greatest attention and upgradation is the changing live load requirement in bridge design code. The challenge increases in developing countries as the pace of infrastructural growth is being catered by the respective country codes with bigger and heavier vehicles to be considered in the design. This paper presents the case study of India where Indian Roads Congress (IRC) codes in its revised version from 2014 to 2017 introduced massive Special vehicle (SV) around 40 m long and weighing 3850 kN to be considered in the design of road bridges. The code does not specify the minimum distance between successive special vehicles unlike other loading classes and hence the consequences of it form the motivation for this study. The effect of SV in comparison with Class 70R, Class AA, Class A, and Class B loading is studied based on the maximum bending moment with moving load applied in Autodesk Robot Structural Analysis. The spans considered in the analysis varied from 10 m to 1991 m corresponding to the span of Akashi Kaikyo Bridge (longest bridge span in the world). A total of 182 analyses for 7 types of vehicles (class B, class A, class 70R tracked, class 70R wheeled, class AA tracked, AA wheeled, and Special vehicle) on 26 different span lengths is carried out. The span corresponding to other vehicles which would equal the bending moment of a single SV is presented along with a comparison relative to Standard Uniformly Distributed Load. Further, the results are presented by introducing a new parameter named Intensity Factor which is proven to relate the effect of axle spacing of vehicle on the normalized bending moment developed.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1994년도 추계학술대회 논문집
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• pp.737-742
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• 1994

In this paper , we propose an incremental approach for recognizing a class of machining features from a featurebased design model as a part design proceeds, utilizing various information such as nominal geometry, design intents, and design feature characteristics. The proposed apptroach can handle complex intersecting features and protrusion features designed on oblique faces. The class of recognized volumetric machining features can be expressed as Material Removal Shape Element Volumes (MRSEVs), a PDES/STEP-based library of machining features.

• 한국정보통신학회논문지
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• 제11권3호
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• pp.500-506
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• 2007

Type Object 디자인 패턴은 하나의 클래스가 수많은 하위 클래스를 갖거나, 그 하위 클래스의 개수를 소프트웨어 개발시에 예측할 수 없는 상황을 해결하고자 제시된 패턴이다. 그러나, 이 패턴은 적용력과 여러 장점에도 불구하고 인스턴스를 생성하는 클래스와 그 인스턴스의 실제적 클래스가 분리되어 있고 또한 객체 레퍼런스에 의해서 서로 연관되어 있으므로 이에 대한 관리를 위한 메커니즘과 패턴의 이해에 있어서 많은 복잡성을 갖는 문제점이 있다. 본 논문에서는 이러한 문제를 해결하기 위한 Type Object Class의 설계와 구현을 제시한다. 즉, Type Object 패턴의 Type Class와 Object Class로부터 Type Object Class를 설정하고, 이를 런타임에 생성되고 사용되게 함으로써, 인스턴스들이 객체 지향프로그래밍 언어에서 제공하는 고유의 클래스를 참조하게 되어 별도의 클래스 참조 메커니즘을 가질 필요가 없도록 하였다. 따라서, 별도의 클래스 참조 메커니즘을 개발하는 부담과 이 메커니즘의 동작으로 인한 실행 상의 성능 저하의 문제가 개선되는 효과가 있다.

• Journal of electromagnetic engineering and science
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• 제2권1호
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• pp.5-10
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• 2002

We have analized the inverse class-F and class-F amplifiers using their waveforms. From the analytic equations derived from the analysis, we have calculated tole efficiencies, output powers, DC power dissipations, and optimum fundamental load impedances of the inverse class-F and class-F amplifiers. We also have compared them for various operation conditions, which include the same peak current, saute DC power dissipation, same fundamental RF output power, and same fundamental load impedance with different Ron(on-resistance). These analyses have clearly shown the performance limitations, advantages, and guide to the optimized design of the inverse class-F amplifiers.