• Nuclear Engineering and Technology
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• 제51권2호
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• pp.463-478
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• 2019

The most important non-functional requirements for dependability of any Embedded Real-Time Safety Systems are safety, availability and reliability requirements. System architecture plays the primary role in achieving these requirements. Compliance with these non-functional requirements should be ensured early in the development cycle with appropriate considerations during architectural design. In this paper, we present an application of system architecture modeling for quantitative assessment of system dependability. We use probabilistic model checker (PRISM), for dependability analysis of the DTMC model derived from system architecture model. In general, the model checking techniques do not scale well for analyzing large systems, because of prohibitively large state space. It limits the use of model checking techniques in analyzing the systems of practical interest. We propose abstraction based compositional analysis methodology to circumvent this limitation. The effectiveness of the proposed methodology has been demonstrated using the case study involving the dependability analysis of safety system of a large Pressurized Water Reactor (PWR).

• 한국정보과학회논문지:소프트웨어및응용
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• 제27권1호
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• pp.13-23
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• 2000

소프트웨어가 점점 복잡해지고 대형화됨에 따라서 사용자의 요구가 매우 다양해지고 있으며, 제품에 대한 기대 수준도 높아지고 있다. 그러므로, 사용자의 요구 사항을 정확히 분석하여 효과적으로 개발 단계에 적용하는 것은 매우 중요하다. 본 논문에서는 자연어로 표현되는 요구 사항 문서의 분석 시에 나타나는 오류를 효과적으로 줄이고, 수정하는데 사용될 수 있는 요구 분석 시스템을 제안한다. 제안된 시스템은 문서간 유사도 측정에 의해서 문서간의 의존성(dependency) 분석을 지원하고 문장간 유사도 측정에 의해서 요구 사항간의 연계성(traceability), 중복성(redundancy), 불일치성(inconsistency), 그리고 불완전성(imcompleteness)을 발견하는 것을 지원한다. 또한 모호한 문장을 추출하여 요구사항의 불명확성 (ambiguity)을 발견하는 기능도 제공한다. 문서간 유사도 측정을 위해서 사용된 색인 방법은 슬라이딩 윈도우 모델과 의존 구조 모델을 결합한 것으로 각 모델이 가지는 단점을 효과적으로 보완할 수 있다. 본 논문에서는 문서간, 문장간 유사도 측정 기법의 효율성을 실험을 통해 검증하였으며 구현된 시스템을 통해 분석 처리되는 과정을 보여주고 있다.

• 대한안전경영과학회지
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• 제9권6호
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• pp.89-96
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• 2007

It is well known that the test and evaluation plan (TEP) is very crucial in the successful development of safety-critical systems. As such, this paper discusses an approach to the development of the TEP for a system that should meet safety requirements in the systems development process. It is studied how to incorporate the result of preliminary hazard analysis (PHA) in generating the safety requirements. It is also discussed how to deal with them when the system requirements (i.e., functions, performance, constraints, components, etc) and the safety requirements are integrated into one model. While doing so, we have constructed the required traceability among them, which is necessary and very useful when the safety requirements need to be corrected or be changed. The use of the traceability makes it possible to easily check out whether and how the safety requirements are properly incorporated in the system design process. Furthermore, without the verified traceability, the system cannot be changed or upgraded later. In order to implement the model on a computer-aided tool, we have constructed a database (DB) schema. As a result, the implemented model/DB allows to automatically generate TEP which can be used to measure the performance and safety level of the developed system.

• 한국군사과학기술학회지
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• 제2권2호
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• pp.52-60
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• 1999

By implementing the Systems Engineering process for the aircraft preliminary design, functional analysis study is performed, hence Functional Interface Data Flow(FIDF) and Functional Flow Block Diagram(FFBD) are generated. Based on FIDF and FFBD, allocable and non-allocable design/performance/RM＆S requirements are allocated to the appropriate levels. Weight and cost tracking and design margin management methodologies are studied and implemented for the balanced aircraft design.

• Journal of Astronomy and Space Sciences
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• 제33권4호
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• pp.323-333
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• 2016

In this study, the uncertainty requirements for orbit, attitude, and burn performance were estimated and analyzed for the execution of the $1^{st}$ lunar orbit insertion (LOI) maneuver of the Korea Pathfinder Lunar Orbiter (KPLO) mission. During the early design phase of the system, associate analysis is an essential design factor as the $1^{st}$ LOI maneuver is the largest burn that utilizes the onboard propulsion system; the success of the lunar capture is directly affected by the performance achieved. For the analysis, the spacecraft is assumed to have already approached the periselene with a hyperbolic arrival trajectory around the moon. In addition, diverse arrival conditions and mission constraints were considered, such as varying periselene approach velocity, altitude, and orbital period of the capture orbit after execution of the $1^{st}$ LOI maneuver. The current analysis assumed an impulsive LOI maneuver, and two-body equations of motion were adapted to simplify the problem for a preliminary analysis. Monte Carlo simulations were performed for the statistical analysis to analyze diverse uncertainties that might arise at the moment when the maneuver is executed. As a result, three major requirements were analyzed and estimated for the early design phase. First, the minimum requirements were estimated for the burn performance to be captured around the moon. Second, the requirements for orbit, attitude, and maneuver burn performances were simultaneously estimated and analyzed to maintain the $1^{st}$ elliptical orbit achieved around the moon within the specified orbital period. Finally, the dispersion requirements on the B-plane aiming at target points to meet the target insertion goal were analyzed and can be utilized as reference target guidelines for a mid-course correction (MCC) maneuver during the transfer. More detailed system requirements for the KPLO mission, particularly for the spacecraft bus itself and for the flight dynamics subsystem at the ground control center, are expected to be prepared and established based on the current results, including a contingency trajectory design plan.

• 시스템엔지니어링학술지
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• 제18권2호
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• pp.50-57
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• 2022

Along with the development of the 4^th Industrial Revolution technology, artificial intelligence technology is also being used in the field of systems engineering. This study analyzed the development status of artificial intelligence technology in the areas of systems engineering core processes such as stakeholder needs and requirements definition, system requirement analysis, and system architecture definition, and presented future technology development directions. In the definition of stakeholder needs and requirements, technology development is underway to compensate for the shortcomings of the existing requirement extraction methods. In the field of system requirement analysis, technology for automatically checking errors in individual requirements and technology for analyzing categories of requirements are being developed. In the field of system architecture definition, a technology for automatically generating architectures for each system sector based on requirements is being developed. In this study, these contents were summarized and future development directions were presented.

• 통상정보연구
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• 제15권4호
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• pp.69-95
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• 2013

본 연구는 물류업계에서 요구하는 인력의 자격요건을 파악하기 위하여 물류분야의 채용공고를 수집하고 내용분석기법을 활용하여 실증분석을 실시하였다. 분석을 위하여 332개의 관련 구인광고를 온라인상에서 조사하였고, 조사를 통해 수집된 광고문구를 단어와 문장단위로 분석하여 그 빈도를 파악하고, 비슷한 자격요건들을 카테고리별로 구분하였다. 정리된 카테고리별 데이터를 바탕으로 내용분석을 실시하여 운송, 택배, 생산, 보관, 포워딩, 무역, 3PL, 컨설팅, 공기업 및 연구소 등 물류관련 업계에서 요구하는 자격요건이 무엇인지 비교 분석함으로써 이 분야의 취업을 계획하는 사람들에게 구체적인 정보를 제공하고자 하였다.

• 한국CDE학회논문집
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• 제16권6호
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• pp.449-457
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• 2011

The productivity improvement is indispensible to shipbuilding industry for maintaining the world's No. 1. Simulation based production recently has been an issue as prat of efforts to high efficiency production and Korean shipyards requests simulation system tools specialized in a shipbuilding industry. IT convergence project between conventional shipbuilding industry and IT simulation technology has been carried out and integrated simulation framework was proposed as a way to overcome sporadic developments. The framework would provide reusability of kernels and modules and also ensure for expansibilities to other production simulations. The fact that production simulation system should reflect shipyard requirement would be most important. We suggest an analysis process of customer requirements and functional requirements for production simulations. It is partially based on concepts of software engineering and axiomatic design. The process is applied to a design of configuration for simulation framework.

• 지식경영연구
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• 제14권1호
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• pp.121-132
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• 2013

In education, innovative ways of teaching and learning are always under development and keep being proposed with advanced concepts since the ancient times. Student-centered learning, problem-based learning and cooperative learning have been three major trends under development in secondary education research and practice more than a decade or so. Combined with advanced information and communication technologies, these trends will greatly transform the way we teach and learn in classroom environment and may change the classroom environment itself, into a more interactive and self-centered coaching type environment. In this study, a smart environment that utilizes advanced information technology devices and network is conceptualized, accommodating requirements contained and proposed in the recent trendy pedagogies. Pedagogical cases discussed in these trends are analyzed in detail, producing requirements for such a learning and coaching environment. These requirements are modeled using unified modeling language, leading to a proposal of a basic architecture for an information system supporting this environment.

• 품질경영학회지
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• 제42권3호
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• pp.339-360
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• 2014

Purpose: The objective of this paper was to analyze the requirements of the end-users by class after carrying out a survey on the user requirements for sleeping bags and utilize the result for effective product development. Methods: The test for difference in means by class was conducted through one sample analysis and one-way ANOVA after the survey result has gone through a reliability verification, and an LSD (Least Significant Difference) test was conducted as a post-mortem method. Results: A significant result was derived from the survey on the user requirements for sleeping bags by method of use, use of combination of sleeping bag components or a sleeping bag alone. Conclusion: The significant result derived from the survey of this paper on the user requirements for sleeping bags can be utilized for effective development of sleeping bags.