• 시스템엔지니어링학술지
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• 제11권1호
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• pp.55-65
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• 2015

In steel making plant, sampling system for raw material such as iron ore, limestone is necessary for quality control purpose. For the sake of efficiency and productivity, automation of the sampling system is highly desirable. From technical standpoint, the development of the automated system requires multi-disciplinary domain knowledge such as mechanical engineering, industrial engineering, information technology and computer engineering. Up to present time, the development has been mainly carried out by a single domain expert with project manager. The automated system developed in this way caused problems in the final system. This paper suggests a systems engineering approach to the development of automation for raw material sampling plant via a tailored process called Plant Systems Engineering (PSE) Process based on ISO/IEC 15288. Through the PSE process, we could derive right requirements and architecture of the Systems Of Interest (SOI), and we were convinced that the PSE Process can be applied to many other Plant Systems.

• 항공우주기술
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• 제5권2호
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• pp.53-59
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• 2006

시스템 엔지니어링은 하나의 학문분야로 인지되어온 이래, 프로젝트의 성공적인 완료를위한 기술적인 선도학문으로서 그 역할을 수행하여 왔다. 또한, 오늘날 치열한 경쟁시장 속에서 프로젝트를 수행하는 많은 조직들은 다양한 프로젝트 이해 당사자의 요구와 기대를 충족시키기 위해 시스템 엔지니어링을 적용해오고 있다. 본 논문은 시스템 엔지니어링 표준의 기본적인 내용과 발전추세 등을 기반으로 항공기 개발 프로젝트에 조정하여 적용한 시스템 엔지니어링 프로세스를 기술하고자 한다.

• 시스템엔지니어링학술지
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• 제4권2호
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• pp.15-26
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• 2008

The Korean High-speed train was developed during 1996 to 2007. This development project consists of many sub-projects and the train-system includes a lot of sub-systems. In order to promote the project on planned cost and time effectively, we tried to apply systems engineering process during the whole life-cycle. The purpose of this paper is to introduce the systems engineering process applied to this project. Activities carried out in each phase such as pre-design, detailed-design, integration & verification are described.

• 한국분말재료학회지
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• 제29권6호
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• pp.453-458
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• 2022

We successfully synthesize water-dispersible CTAB-capped CdSe@ZnS quantum dots with the crystal size of the CdSe quantum dots controlled from green to orange colors. The quenching effect of Fe(DTC)₃ is very efficient to turn off the emission light of quantum dots at four molar ratios of the CdSe quantum dots, that is, the effective covering the surface of quantum dots with Fe(DTC)₃. However, the reaction with Fe(DTC)₃ for more than 24 h is required to completely realize the quenching effect. The highly quenched quantum dots efficiently detect nitric oxide at nano-molar concentration of 110nM of NO with 34% of recovery of emission light intensity. We suggest that Fe(DTC)₃-hybridized CdSe@ZnS quantum dots are an excellent fluorescence resonance energy transfer probe for the detection of nitric oxide in biological systems.

• 한국지능시스템학회논문지
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• 제11권7호
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• pp.653-658
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• 2001

In this paper, we find the necessary and sufficient conditions for the discrete time nonlinear system to be transformed into observable canonical form by state coordinates change. Unlike the continuous time case, our theorems give the desired state coordinates change without solving partial differential equations. Also, our approach is applicable to both autonomous systems and control systems by slight change of the definition of the vector field.

• 대한기계학회논문집 C: 기술과 교육
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• 제1권2호
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• pp.199-204
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• 2013

국가 연구 개발 사업을 통해 수행된 도시형 자기 부상 열차 실용화 사업은 중저속 자기부상열차시스템 개발기술을 확보하고 시범노선 구축 및 시험운행을 통해 상용화를 목적으로 자기부상열차로서 국내에서는 최초의 상용화이며 완전무인운전시스템 구현을 목표하고 있다. 본 연구는 사업에 참여하는 기업, 연구소들의 시스템엔지니어링 활동의 핵심이라고 할 수 있는 도시형자기부상열차 시스템요구사항을 개발하고, 요구사항을 기반으로 도출된 추적성 기법을 제안하였다. 본 논문에서는 사업 전주기에 걸쳐 관리할 수 있는 체계를 정립하고, 카테고라이징 및 DB화를 통하여, 사용자 중심의 엔지니어링 도구를 개발함으로써, 도시형 자기부상열차 시스템의 개발 및 구축을 효과적으로 지원할 수 있도록 하였다.

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.18-29
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• 2015

State Estimation (SE) is the basis of a variety of advanced applications used in most modern power systems. An SE problem formed with enough phasor measurement units (PMUs) data is simply a linear weighted least squares problem requiring no iterations. Thus, designing a minimum-cost placement of PMUs that guarantees observability of a power system becomes a worthy challenge. This paper proposes an equivalent integer linear programming method for substation-oriented optimal PMU placement (SOOPP). The proposed method uses an exhaustive search to determine a globally optimal solution representing the best PMU placement for that particular power system. To obtain a more comprehensive model, contingencies and the limitation of the number of PMU measurement channels are considered and embodied in the model as changes to the original constraints and as additional constraints. The proposed method is examined for applicability using the IEEE 14-bus, 118-bus and 300-bus test systems. The comparison between SOOPP results and results obtained by other methods reveals the excellence of SOOPP. Furthermore, practical large-scale power systems are also successfully analyzed using SOOPP.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권10호
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• pp.2493-2508
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• 2012

The performance of a MIMO system with adaptive modulation (AM) and space-time coding over Ricean fading channels for perfect and imperfect channel state information (CSI) is presented. The fading gain value is partitioned into a number of regions by which the modulation is adapted according to the region the fading gain falls in. Under a target bit error rate (BER) constraint, the switching thresholds for AM are given. Based on these results, we derive the calculation formulae of the theoretical spectrum efficiency (SE) and average BER. As a result, closed-form SE expression and accurate BER expression are respectively obtained. Besides, using the approximation of complementary error function, a tightly closed-form approximation of average BER is also derived to simplify the calculation of accurate theoretical BER. Computer simulation shows that the theoretical SE and BER are in good agreement with the corresponding simulation, and the approximate BER is also close to the accurate one. The results show that the AM scheme in Ricean fading channel provides better SE than that in Rayleigh fading channel due to the direct-path propagation, and has performance degradation in SE and BER for imperfect CSI.

• 시스템엔지니어링학술지
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• 제5권2호
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• pp.35-42
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• 2009

A newly established provision to enforce the systems engineering was added in the regulation for arms acquisition management in January 2009, and a systems engineering guidelines for defence acquisition is being developed. In this paper we conduct a comparative study of the defence acquisition system in the United States and the Republic of Korea, and propose a improving plan about the domestic defence acquisition system.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2014년도 제49차 동계학술대회논문집 22권1호
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• pp.299-302
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• 2014

현대사회에서 인간은 스마트폰에서 발생하는 디지털 효과음과 함께 살아간다. 그러나 이러한 디지털 소음때문에 자의와 상관없이 타인에게 피해를 주고 있다. 이러한 디지털 소음공해를 방지하기 위해 이미 몇몇 응용프로그램이 존재한다. 하지만 사용자의 욕구를 만족시켜주는 것은 없었다. 이러한 연유로, 사용자들의 요구사항을 충분히 반영하여 디지털 소음공해 방지를 위한 안드로이드 플랫폼 기반의 새로운 모바일 응용프로그램을 제시한다. 본 응용프로그램의 사용으로 인하여 타인의 생활에 방해를 주는 행동이 줄어들 것으로 예상된다.