• 시스템엔지니어링학술지
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• 제18권1호
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• pp.58-65
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• 2022

An application case of systems engineering (SE) processes for the small unmanned aerial vehicle (UAV) development project, which was funded by the Korean government during June 2017 ~ August 2020, is briefly presented in this paper. From the beginning to the end of the project, SE processes had been applied and managed by simple and intuitive aspects for the small/medium business companies joined with insufficient experiences of SE. And the specific considerations of the processes were focused to the missions of disaster and public safety purposes required from the government, such as identification, patrol, fire, rescue, etc. As a result, the project applied by the tailored SE processes had been rated of a good and higher accomplishment on the final evaluation, and then the related several programs were prepared successively for the other opportunities.

• 시스템엔지니어링학술지
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• 제10권2호
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• pp.33-42
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• 2014

There have been growing demand of Light Rail Transit(LRT) which have a lot of advantages such as construction costs lower than the recent subway, reduction of operational costs, availability of line planning, operation of railway non-beneficiary region, flexible operations of trains, unmanned operation and also have eco-friendly advantages, it is now becoming urban railway systems when environmental issues have been highlighted all over the world. Therefore, RAMS(Reliability, Availability, Maintainability, Safety) Process and activities for effective implementation of light rail transit projects have become a very important element, and also the utilization of computerized tools to perform these more systematically and productively is sought after these days. In this paper, we have presented a plan that can support the RAMS activities by utilizing the function of the computerized SE(Systems Engineering) tool(CORE$^{(R)}$). Through support of the computerized SE tool, it would be possible more clear and efficient railway project execution.

• 시스템엔지니어링학술지
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• 제3권1호
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• pp.1-7
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• 2007

For the systems engineering process-based development, all requirements of 'Smart UAV Development Program' have been constructed as the database of CORE(R), computer aided systems engineering tool. In this paper, the construction and application of model-based test & evaluation system using those database is described, which prevents omitting essential tests and performing unnecessary rests and enables automatic reflection of database changes and standardization of document formats.

• Journal of electromagnetic engineering and science
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• 제10권3호
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• pp.104-116
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• 2010

With several advantages such as flexible downlink-to-uplink(DL-to-UL) ratio and flexible spectrum usage, Time Division Duplexing(TDD) is emerging as an alternate to Frequency Division Duplexing(FDD), especially in wireless broadband systems. We already have at least four different TDD systems in the industry: Time Division-Synchronous Code Division Multiple Access(TD-SCDMA), IEEE 802.16e-TDD, IEEE 802.16m-TDD, and Time Division-Long Term Evolution(TD-LTE). A disadvantage of TDD is that tight coordination such as time synchronization between adjacent operators is required to prevent interference between the adjacent TDD systems. In this paper, we investigate coexistence scenarios among the above four well-known TDD systems and calculate spectral efficiency(SE) loss in each scenario. Our findings are that SE loss can be significant if TDD ratios of the adjacent operators are considerably different. However, as long as the TDD ratios of the adjacent operators are similar, configurations in the systems permit perfect time synchronization between the two heterogeneous TDD systems, and the resulting SE loss is zero or reasonably low. We believe that the above findings and the configurations of the TDD systems recommended tominimize SE loss will be helpful for operators who deploy TDD systems in system parameter determination and cross-operator coordination.

• 시스템엔지니어링학술지
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• 제11권2호
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• pp.107-113
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• 2015

체계적이고 효율적인 경량전철시스템 건설 및 운영을 위해 시스템엔지니어링(SE) 기술의 적용은 필수적인 활동이 되었다. 이에 따라 사업수행과정에서 다양한 요구사항과 위험요소를 적기에 식별하고 조치하는 시스템엔지니어링 인력의 전문성이 매우 중요하게 고려되고 있다. 이에 본 연구에서는 경량전철 시스템엔지니어링 사업과 관련된 이해관계자들(획득자 및 공급자, 그리고 협력업체 등)을 위한 SE 교육교재를 개발하여 사업수행 전 및 수행과정에서 활용할 수 있도록 하였다. 교육교재는 일반(공통)과정, 수행자(실무자)과정, 심화수행자(관리자)과정)으로 구분하여 개발하였다. 이는 경량전철사업의 성공과 우수한 성과 창출을 위해 중요한 역할을 할 것으로 기대된다.

• Safety and Health at Work
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• 제8권1호
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• pp.94-98
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• 2017

Background: Physical activity (PA) is ranked as a leading health indicator and the workplace is a key setting to promote PA. The purpose of this study was to examine how goal-setting and exercise self-efficacy (SE) during a health promotion program influenced PA level among Japanese workers. Methods: Using a cross-sectional study design, we surveyed 281 employees. The short version of the International Physical Activity Questionnaire was used to assess PA level. Exercise SE was assessed using a partially modified version of Oka's exercise SE scale. Personal goals were assessed as the total numbers of "yes" responses to five items regarding "details of personal goals to perform PA". A mediational model was used to examine whether exercise SE mediates between the number of personal goals and PA level. Results: The mean age of the participants was 46.3 years, 76.2% were men, and the most common occupational category was software engineer (30.6%). The average PA level per week exceeded the recommended level in 127 participants (45.2%). One hundred and eighty-four participants (65.5%) set some form of concrete personal goal to perform PA. The relationship between the number of personal goals and PA level was mediated by exercise SE. Conclusion: Our study showed that exercise SE mediates goal-setting and increases PA. The results suggest that the components of PA promotion programs should be tailored to enhance participants' confidence in performing PA.

• 시스템엔지니어링워크숍
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• 통권6호
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• pp.130-133
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• 2005

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1798-1805
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• 2010

The Railroad Safety Technology R&D Program has been supported by the Ministry of Land, Transport and Maritime Affairs. The Program consists of dozen or more projects and thus is quite complex, which requires effective project management. This paper is discussing how to effectively manage the railroad safety technology R&D program based on systems engineering management plan (SEMP). The key issues dealt in this paper include the SE management, requirements management, verification and validation, integrated data base management, and traceability management. To achieve the goal, we first defined an appropriate SE process to be adopted in the program and the result was documented in the systems engineering management plan. According to the process defined, we set up the environmental frame in database. Using the database and SEMP, each project of the program was verified with respect to the corresponding requirements utilizing the traceability. All these efforts were carried out using a computer-aided SE tool, which enables efficient management of complex database.

• 시스템엔지니어링학술지
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• 제7권1호
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• pp.31-41
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• 2011

The purpose of this paper is to provide an abstracted meta-model for executing Capabilities Portfolio Management (CPM) effectively based on DoDAF2.0. The purpose of developing an architecture is for beneficial use of it. A good set of architectural artifacts facilitates the manipulation and use of them in meeting its usage objectives well. Systems engineering methodologies evolve to accommodate or to deal with enterprise or SoS/FoS level problems. And DoD's Capabilities Portfolio Management (CPM) is a good example which demonstrates enterprise or SoS level problems. However, the complexity of the architecture framework makes it difficult to develop and use the architecture models and their associated artifacts. DoDAF states that it was established to guide the development of architectures and to satisfy the demands of a structured, repeatable method for evaluating alternatives which add value to decisions and management practices. One of the objectives of DoDAF2.0 is to define concepts and models usable in CPM which is one of DoD's six core processes. However, DoDAF and various guidelines state requirements for CPM rather than how to. This paper provides methodology for CPM which includes process and tailored meta-models based on DoDAF Meta Model (DM2).

• 한국산학기술학회논문지
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• 제19권11호
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• pp.96-104
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• 2018

함정은 다양한 탑재장비들과 함정 플랫폼이 통합되어 성능을 발휘해야 하는 복합 무기체계이면서, 장기간의 획득기간이 소요되고 시제품이 바로 전력화 되어야 하는 특징으로 인해 독자적인 개발프로세스를 적용해 왔다. 그러나 최근 기술의 발전과 탑재장비의 복잡화에 따라 함정 획득 분야에도 시스템공학(SE) 절차의 적용이 필수불가결하게 되었다. 그럼에도 불구하고 함정 설계에서 아직까지 SE 절차는 기존의 절차와 융합되지 못하고 별도의 체계로 관리되고 있는데, SE 절차를 반영한 실질적인 통합 프로세스가 아직 정립되어 있지 않기 때문이다. 다양한 함정에 대해 SE 절차의 적용 및 설계 방법 개선 연구가 수행되었으나 통합 측면에서 성과는 부족하였다. 따라서 함정을 설계할 때 적용할 수 있는 SE 기반 통합 프로세스 연구가 필요하다. 본 논문에서는 기존 기본설계 프로세스와 SE 기반 프로세스의 통합을 통해 잠수함 기본설계 프로세스를 정립하였다. 이를 위해 함정 기본설계와 병행하여 SE 기반의 기술검토인 체계요구조건검토(SRR), 체계기능검토(SFR), 기본설계검토(PDR)을 수행하는 방법론을 제시하였다. 그리고 체계요구사항명세서(SSRS), 체계/부체계규격서(SSS), 체계/부체계설계기술서(SSDD) 등의 요구사항 문서들의 생성 및 관리를 위한 효율적인 프로세스를 연구하였다. 이러한 2가지의 프로세스를 통합하여 개선된 SE 기반 기본설계 프로세스를 구축하였다. 구축된 프로세스의 적용성을 평가하기 위하여 현재 기본설계를 진행중인 잠수함에 적용한 결과를 제시하였다. 이를 통해 잠수함의 효과적인 요구사항 관리, 산출물 작성 및 설계반영이 가능하였고, 요구사항과 추적성을 가진 각각의 산출물은 기본설계 시험평가 자료로도 즉각적으로 활용이 가능함을 확인하였다. 잠수함 이외에도 건조중인 다양한 함정 설계에서도 본 연구의 SE 기반 함정 기본설계 프로세스의 유용성이 기대된다.