• KIPS Transactions on Software and Data Engineering
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• v.6 no.5
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• pp.245-256
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• 2017

This paper proposes a method to generate test scripts for testing embedded system in an easy manner by using hierarchical checklist. In the proposed method, a checklist is constructed with event, component and command dictionaries. And the test scripts are hierarchically generated based on the dictionaries. Since the physical layer of system input becomes abstract with component layer and event layer by virtue of the hierarchy, It is possible to generate test scripts without complicated system input information. It is easy to generate test scripts for embedded systems with similar inputs using the highly reusable dictionaries. The effectiveness of the proposed method is demonstrated with experiments.

• The KIPS Transactions:PartD
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• v.12D no.5 s.101
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• pp.745-754
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• 2005

Defence Information System has surely required the guarantee of interoperability between systems as performing task oriented functions. To improve interoperability between them and use the benefits of component based development, defense officers are planning to develop COE like a kind of component bank concept. Defense component development methodology(ADDMe) within COE is a new approach of component based methodology for Defense environment after comparing, analyzing, and synthesizing with traditional CBDs. In this paper we introduce advanced defense component development methodology(ADDMe) and present checklist for improving interoperability between Defence component based systems which are developed with ADDMe. With our proposed interoperability's checklist, we can improve interoperability of defense component based systems through applying per each phase of ADDMe.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.3
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• pp.527-534
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• 2023

Triple modular redundancy (TMR) systems can continue their mission by virtue of their structural redundancy even if one processor is attacked by faults. In this paper, we propose a new fault tolerance strategy by introducing checkpoints into the TMR system in which data saving and fault detection processes are separated while they corporate together in the conventional checkpoints. Faults in one processor are tolerated by synchronizing the state of three processors upon detecting faults. Simultaneous faults occurring to more than one processor are tolerated by re-executing the task from the latest checkpoint. We propose the checkpoint placement and fault detection strategy to maximize the probability of successful execution of a task within the given deadline. We develop the Markov chain model for the TMR system having the proposed checkpoint strategy, and derive the optimal fault detection and checkpoint interval.

• Journal of KIISE:Computer Systems and Theory
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• v.33 no.1_2
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• pp.35-43
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• 2006

An MPI Checkpointer is a tool which provides fault-tolerance through checkpointing The previous researches related to the MPI checkpointer have focused on automatic checkpointing and recovery capabilities, but they haven't considered portability issues. In this paper, we discuss design and implementation issues considered for portability when we developed an MPI checkpointer called STFT. In order to increase portability, firstly STFT supports the abstraction interface for a single process checkpointer. Secondly, STFT uses a user-based checkpointing method, and limits possible checkpointing places a user can make. Thirdly, STFT lets the MPI_Init create network connections to the other MPI processes in a fixed order. With these features, we expect STFT can be easily adaptable to various platforms and MPI implementations, and confirmed STFT is easily adaptable to LAM and MPICH/P4 with the prototype Implementation.

• 한국디지털정책학회:학술대회논문집
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• 2005.11a
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• pp.27-43
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• 2005

정보시스템 감리 시 시간적인 제한과 제한적인 검토로 인하여 문제점 도출에 한계가 있다. 이로 인하여 정보화계획 수립, 분석, 설계, 구현단계 산출물과 시스템에 대한 지적사항이 단편적으로 된다. 본 연구에서는, 정보시스템 감리 보고서에서 지적되었던 프로젝트관리에 대한 검토사항 및 지적사항을 유형별로 분석 하여, 체크리스트를 개선하였고, 이를 적용하여 프로젝트 관리를 효과적으로 하도록 제안하였다. 개선된 체크리스트를 이용하여 정보화 사업관리자가 관리의 포인트로 활용할 수 있고, 감리 시 생산성을 높이며 정보시스템 감리의 품질이 향상 될 것이다. 본 연구에서 제안한 개선된 체크리스트는 향후 자료를 보완하고 유형별 사례를 보완하면 프로젝트 관리 성과 측정 툴로서도 활용될 수 있을 것으로 기대한다.

• Proceedings of the Korea Information Processing Society Conference
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• 2020.05a
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• pp.211-213
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• 2020

최근 키오스크 사용 비중이 커짐으로써 그에 따른 사용자들의 개인 정보에 대한 보안 위협이 증가하였다. 호텔과 같은 숙박업소에서 이용하는 키오스크의 경우 체크인을 하기 위해 사용자들의 개인정보를 입력하는 것은 물론 숙박하는 호실의 정보도 가지고 있다. 이 경우 정보 유출 시 개인 정보 유출 이외의 다른 범죄가 발생할 수 있다. 이와 같은 키오스크 보안의 한계점을 보완하기 위해 본 논문에서는 Tendermint 기반의 블록체인을 이용하여 기존 일방향적인 결제 시스템을 지닌 기존 키오스크 체크인 시스템의 단점을 보완하고 키오스크 체크인의 보안성 및 신뢰성을 강화하는 방법을 제안한다.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.74-76
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• 2011

최근 플래시 메모리에 기반을 둔 임베디드 시스템의 사용이 급증하고 있다. 스마트폰이 대중화됨에 따라, 플래시 메모리용 파일시스템에 대한 필요성이 증가되고 있다. 보편적으로 사용하는 YAFFS2 파일시스템은 초기화 시 오래 걸리는 단점이 존재하여 체크포인트 기능으로 보안 하고 있다. 그러나 갑작스러운 Power Failure 나 언마운트시 체크포인트가 저장되지 않으면 전체 영역을 스캔해야 하는 문제점이 존재한다. 본 논문에서는 YAFFS2의 성능 개선 및 신뢰성 향상을 위한 메타데이터 관리 기법을 제안한다. 메인메모리상에 유지되는 메타데이터의 영역을 나눠서 관리해서, Power Failure 가 발생하거나 체크포인트가 존재하지 않아도 전 영역을 스캔 하는 문제점 을 피할 수 있다.

• KIPS Transactions on Software and Data Engineering
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• v.5 no.12
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• pp.641-652
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• 2016

This paper proposes a method to generate test scripts in an automatic manner, based on checklist used for testing embedded systems in the fields. The proposed method can reduce the mistakes which may be introduced during manual generation. In addition, it can generate test scripts to test various mode combinations, which is not possible to be tested by the typical checklist. The test commands in a checklist are transformed into a test script suit referencing the signal values defined in a test command dictionary. In addition, the method to generate test scripts in sequential, double permutation and random manners is proposed useful to test the inter-operations between modes, a series of operations for a specific behavior. The proposed method is implemented and the feasibility is shown through the experiments.

• Journal of Aerospace System Engineering
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• v.12 no.2
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• pp.7-14
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• 2018

In this study, a new check valve was studied to improve the load pressure of a brake system with a small piezoelectric-hydraulic pump. During the pressurization process, the steady-state pressure at the load is affected by the ratio of the cross-sectional area of the check valve the chamber pressure and load pressure. Since the flow path cover of the check valve is made wider than the cross-sectional area of the output flow to prevent backflow, a method of reducing the area ratio is proposed for a higher load pressure by mounting an additional mass to a thin plate spring type check valve. To identify the effect of mounting an additional mass to the existing check valve on the load pressure, a simple brake system with a small piezoelectric-hydraulic pump was modeled using a commercial code AMESim. The AMESim modeling was verified by comparing the simulation results with the experimental results of the pump the existing check valve. The additional mass was added to the verified AMESim modeling and higher load pressure was able to be obtained through simulation. The 35% performance improvement in load pressure identified by carrying out pressurization test of the brake system after adopting the new check valve the small piezoelectric-hydraulic pump.

• Proceedings of the KIPE Conference
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• 2012.11a
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• pp.185-186
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• 2012

본 논문에서는 HVDC C&P(High Voltage Direct Current Control and Protection) 시스템의 네트워크 이중화 방법을 제안한다. 본 논문에서 제안하는 HVDC C&P 시스템 네트워크 이중화 방법은 2개의 이더넷 라인을 제어기에 직접 연결하고, 연결된 라인으로 동시에 정보를 송신하여, 제어기에서 정보를 필터링하여 사용하는 방법을 사용한다. 또한 네트워크 라인의 효과적인 결선 체크를 위해 제어기간 송수신을 통해 네트워크 라인의 결선을 체크하는 방법을 사용한다. 위와 같은 방법은 HVDC C&P 시스템의 네트워크 안정성을 향상시키는 효과를 기대할 수 있다.