• International Journal of Naval Architecture and Ocean Engineering
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• 제6권4호
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• pp.775-787
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• 2014

Availabilities of subsea Blowout Preventers (BOP) in the Gulf of Mexico Outer Continental Shelf (GoM OCS) is investigated using a Markov method. An updated ${\beta}$ factor model by SINTEF is used for common-cause failures in multiple redundant systems. Coefficient values of failure rates for the Markov model are derived using the ${\beta}$ factor model of the PDS (reliability of computer-based safety systems, Norwegian acronym) method. The blind shear ram preventer system of the subsea BOP components considers a demand rate to reflect reality more. Markov models considering the demand rate for one or two components are introduced. Two data sets are compared at the GoM OCS. The results show that three or four pipe ram preventers give similar availabilities, but redundant blind shear ram preventers or annular preventers enhance the availability of the subsea BOP. Also control systems (PODs) and connectors are contributable components to improve the availability of the subsea BOPs based on sensitivity analysis.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.1125-1128
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• 1998

A new architecture for high-speed implementation of adaptive decision-feedback equalizer (ADFE) applicable to wide-band digital wireless modems is described. Rather than using conventional two's complement arithmetic, a novel complex-valued filter structure is devised, which is based on redundant binary (RB) arithmetic. The proposed RB complex-valued filter reduces the critical path delay of ADFE, as well as leads to a more compact implementation than conventional methods. Also, the carry-propagation free (CPF) operation of the RB arithmetic enhances its speed. To demonstrate the proposed method, a prototype chip set is designed. They are designed to contain two complexvalued filter taps along with their coefficient updating circuits, and can be cascaded to implement loger filter taps for high bit-rate applications.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.246-248
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• 2009

In this paper, we will describe architecture and key characteristic for the DHS which is used in COMS. DHS is implemented in the fully redundant SCU, the dual redundant MIL-STD-1553B system bus, the payload interface units(MPIU and MI2U), the redundant ADE. the SCU interface with the other main digital units of the spacecraft through the MIL-STD-1553B.

• 정보과학회 논문지
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• 제42권8호
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• pp.1010-1021
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• 2015

빅데이터 시스템은 대규모 로그 데이터를 수집하는 용도로 광범위하게 사용되고 있기 때문에 높은 성능을 갖는 것이 매우 중요하지만, 현재의 Hadoop 기반의 빅데이터 시스템은 중복 처리로 인하여 낮은 성능을 갖는 아키텍처적인 문제를 가지고 있다. 본 논문은 아키텍처 설계 개선을 통하여 Hadoop 기반 시스템의 낮은 성능 문제를 해결한다. 새로운 제안 아키텍처는 기존 아키텍처의 배치(Batch) 기반의 데이터 수집 방식을 개별처리 방식과 혼합한 수집 방법을 사용하고, 수집하는 데이터를 In-Memory 상에서 직접 분석하여 중복 처리를 배제하여 높은 성능을 제공하게 한다. 또한 제안 아키텍처는 기존 Hadoop 기반 아키텍처의 장점인 시스템 확장성을 가진다. 본 논문은 제안 아키텍처가 테스트 베드 환경에서 기존 아키텍처보다 데이터의 분석 처리 속도가 30%~35% 빠르고 확장성도 가진다는 것을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.230-234
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• 1989

This paper presents the design of a prototype robot and architecture of a distributed control system. The robot, named as KAEROT, has been developed for the purpose of the reduction of personal radiation exposure and the remote maintenance tasks in nuclear facilities. The mobile system with robotic manipulator has been designed to go up and down stairs. For the dextrous handling, this manipulator will be designed as a redundant type to act like a human arm. Manipulator control system is to be extended easily for further usage with a modular architecture to get independency and reliability by minimizing EMI effects.

• 한국수소및신에너지학회논문집
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• 제34권3호
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• pp.297-306
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• 2023

The frequency of fatal accidents that can occur at hydrogen refueling station was compared with the risk criterion for the general public suggested by the health and safety executive. If hydrogen refueling station meets the accident prevention facility standards presented in KGS Code FP216/217, it was confirmed that the risk of hydrogen refueling station was not at an unacceptable (intolerable) risk level. However, the risk of hydrogen refueling station due to small leak was analyzed as low as reasonably practicable. Therefore, methods for improving the safety instrumented function of hydrogen refueling station were reviewed. It was confirmed that the risk of hydrogen refueling station can be affected by the number of installed safety instrumentation system components, redundant architecture, mission time, proof test interval, etc. And methods for maintaining the risk of hydrogen refueling station at an acceptable risk level have been proposed.

• 제어로봇시스템학회논문지
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• 제19권4호
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• pp.328-333
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• 2013

Since a slight malfunction of control systems in a nuclear power plant may cause huge catastrophes, such control systems usually have multiple redundancy and reliable features, and their reliability and availability should be analyzed and verified thoroughly. This paper performed the reliability analysis of the SPLC (Safety Programmable Logic Controller) that is under developed as the control systems for the next generation nuclear power plant. One of the key features of SPLC is that it has multiple redundancy modes as faults happen, which means the reliability analysis for one fixed redundant model is not enough to analyze the reliability of SPLC. With considering this reconfigurable concept, FTA (Fault Tree Analysis) was used to capture fault-relationship among sub-modules. The analysis results show that MTTF (Mean Time to Fault) of SPLC is 45,080 hours, which is a about 4.5 times longer than the regulation, 10,000 hours.

• 한국정보통신학회논문지
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• 제21권11호
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• pp.2153-2166
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• 2017

웹 앱에는, 서로 다른 웹 페이지를 웹브라우저에 로드할 때 동일 데이터가 반복적으로 획득되고 처리되어 화면상에 표시되는 문제가 있다. 본 논문은 이 문제를 해결하기 위해 자바 웹 앱을 재구조화하는 기법을 제안하고 평가한다. 자바 웹 앱을 MVC(Model-View-Controller) 아키텍처 관점에서 동적 분석하고 컴포지트 뷰 패턴을 활용하여 중복해서 사용되는 데이터를 식별한다. 이를 토대로 페이지 요청 시 중복 데이터가 로드되지 않도록 앱을 재구조화한다. 재구조화를 통해 MVC 아키텍처에 부합하며 성능이 향상된 웹 앱을 생성한다. 이렇게 재구조화된 웹 앱은 기존 웹 앱의 응답 시간을 데스크톱 PC, 모바일 기기에서 각각 38%, 55% 개선하였다. 아울러 오픈 소스 웹 앱을 이용한 사례 연구를 통해 제안하는 기법의 적용 가능성을 보였다.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.405-406
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• 2008

This paper presents a high performance 2D PE architecture for H.264 Motion Estimation(ME). While existing 2D PE architectures reuse the overlapped data of adjacent search windows scanned in 1 or 3-way, the new architecture scan adjacent windows and multiple paths instead of single raster and zigzag scanning of adjacent windows in 4 way(up,down,left,right). By reducing the redundant access factor by 1.4, the new 4-way search window improve the memory bandwidth by 70-58% compared with 1/3-way search window. With Altera Stratix-III implementation, the high performance 2D PE architecture deals with SD ($720{\times}480$) video of 2 reference frame, $48{\times}48$ search area and $16{\times}16$ macroblock by 30fps at 97.1MHz.

• 한국해양공학회지
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• 제29권5호
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• pp.380-385
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• 2015

In the development of an underwater construction robot, the reliability of the operating system is the most important issue because of its huge maintenance cost, especially in a deep sea application. In this paper, we propose a new redundant architectural design for the hydraulic control system of an underwater construction robot. The proposed architecture consists of dual independent modular redundancy management systems linked with a commercial profibus network. A cold standby redundancy management system consisting of a preprocessing switch circuit is applied to the signal network, and a hot standby redundancy management system is adapted to utilize two main controllers.