• Nuclear Engineering and Technology
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• 제53권7호
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• pp.2184-2194
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• 2021

The Free-Piston Stirling engine (FPSE) is of interest for many research in aerospace due to its advantages of long operating life, higher efficiency, and zero maintenance. In this study, a 1-kW FPSE was proposed by analyzing the requirements of Space Reactor Power Systems (SRPS), of which performance was evaluated by developing a code through the Simple Analysis Method. The results of SAM showed that the critical parameters of FPSE could satisfy the designed requirements. The heater of the FPSE was designed with the copper rectangular fins to enhance heat transfer, and the parametric study of the heater was performed with Computational Fluid Dynamics (CFD) software STAR-CCM⁺. The Performance Evaluation Criteria (PEC) was used to evaluate the heat transfer enhancement of the fins in the heater. The numerical results of the CFD program showed that pressure drop and Nusselt number ratio had a linear growth with the height of fins, and PEC number decreased as the height of fins increased, and the optimum height of the fin was set as 4 mm according to the minimum heat exchange surface area. This paper can provide theoretical supports for the design and numerical analysis of an FPSE for SRPSs.

• 한국산업정보학회:학술대회논문집
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• 한국산업정보학회 1997년도 추계학술대회 발표논문집:21세기를 향한 정보통신 기술의 전망
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• pp.417-433
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• 1997

A real-time operating system has focused primary on techniques to minimize processing time, with a secondary emphasis on system reliability issues. Conversely, fault-tolerant system has concentrated on using recourse and information redundancy to maximize the availability and reliability of the system, with a lesser emphasis on performance. We have developed a fault-tolerant and real-time operations system which support a powerful concurrent runtime environment under the above requirements. In this paper, we present an overview of real-time systems, design and implementation of a duplex architecture using advanced concepts and technologies such as fast " fault detection", "fault isolation" and "fault recovery" Because the duplex architecture has two dentical hardware elements and has several recovery steps and hierarchy to facilitate a fast recovery which must be proceeded by a prompt fault detection and isolation. Thus it makes possible to minimize the overhead of the systems including hardware and software and guarantee the service continuity of he systems.

• 한국항행학회논문지
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• 제11권4호
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• pp.473-478
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• 2007

소프트웨어나 디지털콘텐츠의 저작권 보호를 위하여 시리얼 키 입력 방식의 인증 시스템이 널리 이용되고 있다. 하지만 가상의 시리얼 키를 만들거나 하나의 시리얼 키를 여러 사용자가 공유하여 저작권의 보호가 되지 않고 있다. 이에 다양한 암호화 기법을 통해 시리얼 키의 복제를 막으려는 노력이 진행되고 있지만 소프트웨어의 기술만으로는 한계가 있다. 본 논문에서는 보안성이 강화되고 휴대가 편리하여 다양한 분야에서 많이 활용되기 시작한 스마트카드를 이용하여 소프트웨어와 디지털콘텐츠의 저작권 보호를 위한 시리얼 키 인증 시스템을 제안 하였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2004년도 학술대회지
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• pp.532-535
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• 2004

Architecture generation is the first step in the design of software systems. Most of the qualities that the final software system possesses are usually decided at the architecture development stage itself. Thus, if the final system should be usable, testable, secure, high performance, mobile and adaptable, then these qualities or non­functional requirements should be engineered into the architecture itself. In particular, adaptability is emerging as an important attribute required by almost all software systems. The machinery and tools in the remote site surveillance and connects intelligence information machinery and tools at Internet. We need the server which uses different embedded operating system to become private use. With the progress of information-oriented society, many device with advanced technologies invented by many companies. However, the current firmware technologies have many problems to meet such high level of new technologies. In this paper, we have successfully ported linux on an embedded system, which is based on intel StrongARM SA-1 1 10 processor, then written several network modules for internet-based network devices.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 춘계학술대회
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• pp.618-619
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• 2013

본 논문에서는 현재의 IT 분야의 핵심 기술 중에 하나인 임베디드시스템을 하드웨어/소프트웨어 통합설계 방법론에 기초를 두고 구성하는 방법의 한 가지를 제안하였다. 제안한 방법에 기초하여 각 종 진보된 멀티미디어시스템을 구현할 수 있으리라 사료되며, 또한 이를 기반으로 좀 더 진보된 각종 디지털컨텐츠를 구현할 수 있으리라 전망되며, 특히 최근 대두되고 있는 모바일 컨텐츠 구현에 적용이 기대된다.

• Progress in Superconductivity
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• 제1권2호
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• pp.115-119
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• 2000

We designed and constructed a non-destructive evaluation system using an HTS DC SQUID electronic gradiometer. Our DC SQUID electronic gradiometer is composed of two DC SQUID magnetometers. The system included a non-magnetic stainless steel cryostat and a set of coaxial exciting coils, which were used to induce an eddy current in the test piece. We also have calculated the eddy current density produced by an exciting coil in any direction of the testing object. We could compute the eddy current density distribution in 3D. The SQUIDs were computer controlled and the output data from the electronic gradiometer was obtained by using a Labview software.

• ETRI Journal
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• 제28권4호
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• pp.525-528
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• 2006

In this letter, we present a design of a single chip video decoder called advanced mobile video ASIC (A-MoVa) for mobile multimedia applications. This chip uses a mixed hardware/software architecture to improve both its performance and its flexibility. We designed the chip using a partition between the hardware and software blocks, and developed the architecture of an H.264 decoder based on the system-on-a-chip (SoC) platform. This chip contains 290,000 logic gates, 670,000 memory gates, and its size is $7.5\;mm{\times}7.5\;mm$ (using 0.25 micron 4-layers metal CMOS technology).

• 한국IT서비스학회지
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• 제4권2호
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• pp.47-59
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• 2005

S/W product line is a S/W product or a set of S/W system, which has common functions. We can develop a specific S/W product, which satisfiesrequirements of a particular market segment and a mission in a specific domain by reusing the core asset such as the developed S/W architecture through the S/W product line. S/W development methodology based on the S/W product line can develop a S/W more easily and fast by reusing the developed S/W core asset. An advanced country of S/W technology selects S/W product line as a core field of S/W production technology, and support technology development. In case of USA, CMU/SEI (Carnegie Mellon University / Software Engineering Institute) developed product-line framework 4.0 together with the industry and the Ministry of National Defense. Europe is supporting the development of product line technology through ITEA(IT for European Advancement) program. In this paper, we aim to construct reference architecture of S/W product line for production of the S/W product line.

• 한국항행학회논문지
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• 제17권3호
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• pp.346-353
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• 2013

소프트웨어 개발의 주요 동향 중 하나는 소프트웨어 산업의 세계화에 있다. 글로벌 소프트웨어 개발은 여러 가지 문제에 직면해 있다. 이러한 문제를 해결하기 위해 새로운 소프트웨어 개발 방법론과 프로세스가 필요하다. 최근 XP 동향에서의 개발 단계로 본다면 기존의 개발자와 개발자간의 협업을 위한 도구에서 벗어나 조직 구성원 전체가 협업할 수 있는 시스템이 필요하다. 텍스트 기반의 IDE 플러그인 형태나 단순한 화면공유, 채팅 기능을 제공하는 것이 아닌 구성원 전체가 협업할 수 있는 분산 페어 개발을 지원하는 시스템의 설계하고 개발하였다.

• 한국CDE학회논문집
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• 제17권5호
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• pp.333-341
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• 2012

Modeling and simulation is important for military training. People can feel perspective when stereoscope images are created using multi-channel visualizations. A submarine oscillates when the submarine is just below the surface of the sea, so that the reconnaissance becomes difficult. Also, the operator should read the information of the target within 6 seconds using the periscope. The operator must have experience. To solve these problems, stereoscopic multi-channel visualization has been tested. The iCAVE system of KAIST provides a large-scale screen, 7 PCs, and 14 projectors to create the stereoscope images. To simulate the motion of a submarine just below the ocean surface, a 4-DOF motion platform is used. The motion data is transmitted to the visual system and the motion platform through the UDP protocol. Variety of weather conditions are created using the Vega Prime software. The stereoscopic multi-channel visualization and the motion platform system created a realistic simulation system.