• 해양환경안전학회지
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• 제17권3호
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• pp.275-281
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• 2011

선박의 건조 공정 중 병목공정에 해당하며 전적으로 숙련자의 수작업으로만 이루어지는 공정이 곡가공 공정이다. 이러한 곡가공 공정을 자동화 하고자 산업계와 학계의 많은 노력이 경주되었다. 기존의 곡가공 자동화 시스템 개발은 산업계와 학계에서 오랜 동안 연구되어 왔음에도 불구하고 실제로 생산현장에 투입되어 성공적으로 운영되는 사례는 없었다. 본 연구는 이러한 기존 곡가공 자동화 시스템 개발의 문제점을 파악하고 이를 해결할 수 있는 대안으로 요구사항 정의, 시스템 설계, 하부시스템 및 구성요소의 구현, 시스템 통합 및 검증의 4단계 시스템 엔지니어링 기반의 시스템 개발방법론을 제안하였다. 제안된 개발방법론을 기반으로 선체 곡가공 자동화 시스템 프로토타입 개발에 적용하고 결과를 고찰하여 기존 곡가공 자동화 시스템 개발에서의 문제점을 해결할 수 있는 대안이 될 수 있음을 확인하였다.

• Nuclear Engineering and Technology
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• 제39권1호
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• pp.51-62
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• 2007

To efficiently design safety-critical systems such as nuclear power plants, with the requirement of high reliability, methodologies allowing for rigorous interactions between the synthesis and analysis processes have been proposed. This paper attempts to develop a reliability-centered design framework through an interactive process between Axiomatic Design (AD) and Fault Tree Analysis (FTA). Integrating AD and FTA into a single framework appears to be a viable solution, as they compliment each other with their unique advantages. AD provides a systematic synthesis tool while FTA is commonly used as a safety analysis tool. These methodologies build a design process that is less subjective, and they enable designers to develop insights that lead to solutions with improved reliability. Due to the nature of the two methodologies, the information involved in each process is complementary: a success tree versus a fault tree. Thus, at each step a system using AD is synthesized, and its reliability is then quantified using the FT derived from the AD synthesis process. The converted FT provides an opportunity to examine the completeness of the outcome from the synthesis process. This study presents an example of the design of a Containment Heat Removal System (CHRS). A case study illustrates the process of designing the CHRS with an interactive design framework focusing on the conversion of the AD process to FTA.

• 한국융합학회논문지
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• 제10권11호
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• pp.143-148
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• 2019

현대 사회에서 안전 서비스 및 시스템 환경을 구축하고 활용하는 것은 매우 중요하고 관심이 큰 분야이다. 특히, 어린이, 고령자, 여성, 장애인 및 외국인 등 사회적 취약 계층에 대한 안전 서비스 제공은 사회적 이슈가 되고 있다. 그러나, 대부분의 안전 서비스 및 시스템은 일반인을 대상으로 적용되고 있기 때문에 사회적 취약 계층을 위한 시스템 개발이 필요하다. 따라서, 본 논문에서는 실시간으로 상황을 인식하고, 신속한 대응을 할 수 있도록 데이터를 처리, 전송하는 시스템 모듈을 개발하였다. 이를 위해, 실시간 상황 인식에 필요한 다양한 센서를 통합 모듈로 설계하고, 이를 통해 수집된 데이터를 분석하여 처리 결과를 전송하는 안전 시스템 모듈을 개발하였다.

• Nuclear Engineering and Technology
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• 제54권3호
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• pp.896-908
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• 2022

As a part of probabilistic risk (or safety) assessment (PRA or PSA) of nuclear power plants (NPPs), the primary role of human reliability analysis (HRA) is to provide credible estimations of the human error probabilities (HEPs) of safety-critical tasks. In this regard, it is vital to provide credible HEPs based on firm technical underpinnings including (but not limited to): (1) how to collect HRA data from available sources of information, and (2) how to inform HRA practitioners with the collected HRA data. Because of these necessities, the U.S. Nuclear Regulatory Commission and the Korea Atomic Energy Research Institute independently developed two dedicated HRA data collection systems, SACADA (Scenario Authoring, Characterization, And Debriefing Application) and HuREX (Human Reliability data EXtraction), respectively. These systems provide unique frameworks that can be used to secure HRA data from full-scope training simulators of NPPs (i.e., simulator data). In order to investigate the applicability of these two systems, two papers have been prepared with distinct purposes. The first paper, entitled "SACADA and HuREX: Part 1. The Use of SACADA and HuREX Systems to Collect Human Reliability Data", deals with technical issues pertaining to the collection of HRA data. This second paper explains how the two systems are able to inform HRA practitioners. To this end, the process of estimating HEPs is demonstrated based on feed-and-bleed operations using HRA data from the two systems.

• 인터넷정보학회논문지
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• 제20권3호
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• pp.1-11
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• 2019

자동차, 원자력, 철도, 항공 등의 분야에서 발생하는 소프트웨어의 고장이나 사고는 바로 큰 재산 피해나 인명 피해로 연결될 수 있다. 이에 체계적이고도 효과적인 안전품질 관리의 필요성이 커지고 있으며, 최근 관련 산업 분야에서는 IEC 61508을 기반으로 안전 국제 표준이 제정되어 산업에 적용되고 있다. 국제 표준에서 명시하고 있는 안전 생명주기에 따르면 소프트웨어 안전성 품질을 확보하기 위해서는 개발 초기 단계에서 위험원 및 위험 분석(Hazard and risk analysis)을 통한 안전 요구사항을 개발하도록 권고하고 있다. 본 논문에서는 소프트웨어의 안전성 요구사항의 식별 및 정의를 위해 SysML을 활용한 STPA 기반의 위험원 분석 프로세스를 제안한다. 세부적으로는 SysML의 BDD과 IBD 다이어그램을 활용하여 기존 STPA 분석에서 활용되고 있는 제어구조도를 보다 명확하게 정의할 수 있도록 개선하였고, SD 다이어그램을 활용하여 안전 제약사항(요구사항)을 상세화할 수 있도록 하였다. 제안 방법의 적용 결과, STPA에서 누락되었던 위험원을 추가적으로 식별할 수 있었고, 위험원의 발생 시나리오도 상세하게 구체화할 수 있었다.

• 시스템엔지니어링학술지
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• 제9권1호
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• pp.33-45
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• 2013

Systems Engineering Approach was applied to the development of operator-support core management system based on the on-site operation experience and document of core management procedures, which is for enhancing operability and safety in PHWR (Pressurized Heavy Water Reactor) operation. The dissertation and definition of the system were given on th basis of investigating and analyzing the core management procedures. Fuel management, detector calibration, safety management, core power distribution monitoring, and integrated data management were defined as main user's requirements. From the requirements, 11 upper functional requirements were extracted by considering the on-site operation experience and investigating documents of core management procedures. Detailed requirements of the system which were produced by analyzing the upper functional requirements were identified by interviewing members who have responsibility of the core management procedures, which were written in SRS (Software Requirement Specification) document by using IEEE 830 template. The system was designed on the basis of the SRS and analysis in terms of nuclear engineering, and then tested by simulation using on-site data as a example. A model of core power monitoring related to the core management was suggested and a standard process for the core management was also suggested. And extraction, analysis, and documentation of the requirements were suggested as a case in terms of systems engineering.

• Journal of Information Processing Systems
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• 제19권2호
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• pp.139-148
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• 2023

Current food-traceability platforms suffer from problems such as inconsistent traceability standards, a lack of public credibility, and slow access to data. In this work, a combined code and identification method was designed that can achieve more secure product traceability using the dual anti-counterfeiting technology of a QR code and a hidden code. When the QR code is blurry, the hidden code can still be used to effectively identify food information. Based on this combined code, a food-safety traceability platform was developed. The platform follows unified encoding standards and provides standardized interfaces. Based on this innovation, the platform not only can serve individual food-traceability systems development, but also connect existing traceability systems. These will help to solve the problems such as non-standard traceability content, inconsistent processes, and incompatible system software. The experimental results show that the combined code has higher accuracy. The food-safety traceability platform based on the combined code improves the safety of the traceability process and the integrity of the traceability information. The innovation of this paper is invoking the combined code united the QR code's rapidity and the hidden code's reliability, developing a platform that uses a unified coding standard and provides a standardized interface to resolve the differences between multi-food-traceability systems. Among similar systems, it is the only one that has been connected to the national QR code identification platform. The project has made profits and has significant economic and social benefits.

• 한국안전학회지
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• 제31권4호
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• pp.156-163
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• 2016

There exists required safety integrity level (SIL) to assure safety in accordance with international standards for every electrical / electronics / control equipment or systems with safety related functions. The SIL is allocated from lowest level (level 0) to highest level (level 4). In order to guarantee certain safety level that is internationally acceptable, application of methodology for SIL allocation and demonstration based on related international standards is required. However, the theoretical and practical study for safety integrity level is barely under way in the domestic railway industry. This research studied not only the global process of SIL allocation to guarantee safety in accordance with international standards for safety related equipment and system, but the quantitative methodology based on international standard and the semi-quantitative methodology as alternative way for SIL allocation. Specifically, the systematic SIL allocation for platform screen door system of railway is studied applying the semi-quantitative methodology in order to save much time and effort compared to quantitative method.

• 한국항공운항학회지
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• 제27권3호
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• pp.90-97
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• 2019

The International Civil Aviation Organization(ICAO) recently established the Global Aviation Safety Plan(GASP) for national aviation safety management, along with the enactment of Annex 19, Safety Management System(SMS). ICAO require the establishment of the 'States Safety Programs(SSP)' for countries with excellent safety evaluation, including Korea, and the establishment of aviation safety supervision systems for all Contracting States by 2017 under the enactment of ICAO Annex 19. Required. The Ministry of Land, Infrastructure, and Transport has continuously invested in R&D to secure such aviation safety systematically, and is making efforts to develop and disseminate related technologies by establishing long-term R&D roadmaps. A study on aviation safety supervision among the system-based aviation safety supervision support technology development R&D project, which is underway as part of the aviation safety technology development project of the Ministry of Land, Infrastructure and Transport. We conducted a study to see if this methodology logically guarantees reasonableness.

• 한국환경보건학회지
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• 제49권2호
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• pp.78-88
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• 2023

Background: Exposure to volatile organic compounds (VOCs) can have acute and chronic health effects on human beings in general and in working environments. In particular, VOCs are often emitted in large quantities in industrial settings. In such circumstances, there is a need to improve the indoor air quality at workplaces. Objectives: The purposes of this study were to verify the effectiveness of air cleaning devices in workplaces and provide alternative solutions for improving working environments. Methods: Personal exposure and area level of VOCs for workers were evaluated in a car-part adhesive process before and after installing an air cleaning device with a TiO₂-coated filter. Passive samplers and direct reading instruments were used to collect and analyze the VOCs, and the removal efficiency and improvement of air quality were evaluated. We also calculated the exposure index (EI) to assess the risk level in the workplace. Results: The removal efficiency for VOCs through the installation of the air cleaning device was approximately 26.9~69.0% as determined by the concentration levels before and after installation. The measured substances did not exceed the exposure limits for the work environment and the EI was less than 1. However, carcinogenic substances such as benzene, formaldehyde, carbon tetrachloride, and trichloroethylene were detected. Conclusions: The application of an air cleaning device can be a solution for controlling the indoor air quality in a workplace, particularly in cases where ventilation systems cannot be installed due to process limitations.