• 방재저널
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• 제15권4호
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• pp.136-137
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• 2013

• 대한산업공학회지
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• 제37권4호
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• pp.390-399
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• 2011

Generally the life-cycle cost of complex systems composed of several sub systems or equipments such as train, aircraft weapon systems is spent much more during operation and maintenance phase than development phase. The maintenance cost for maintaining the availability and extending the life span of systems comprise a large proportion of systems operation cost. The cycle of preventive maintenance affects operation and maintenance cost a lot. In this study we introduce a way minimizing life-cycle cost of systems by calculating more reliable preventive maintenance period than the results of previous study using systems reliability data considered the reliability and failure effect ratio of sub-systems or components. We can solve the preventive maintenance period problem known as NP-Hard as quick as possible by using modified genetic algorithm than using other models introduced in previous study.

• 시큐리티연구
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• 제57호
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• pp.137-156
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• 2018

본 연구는 개방 시스템과 통합 시스템의 이론을 준거로 파악하고, 대테러시스템 구축 및 운영을 법률 부문과 운영 부문으로 선정하여 대테러시스템 현황 분석을 검토한 후, 대테러 관련 종사자들의 인식을 파악하여 이에 따른 방향을 제시하는데 그 목적이 있다. 연구수행 결과 첫째, 대테러시스템의 특성과 관련하여 개방형 시스템과 통합형 시스템에 대한 동의 정도가 낮게 형성되어지고 있는바 인식이 저조한 것으로 나타났다. 둘째, 대테러시스템 구축 및 운영 주요 요인의 중요도 및 필요도와 관련하여 컨트롤 타워 재정비의 경우 중요도와 필요도 각각 높은 순위로 대테러 관련 종사자들은 이를 가장 중요하고 필요하다고 인식하고 있다. 국제적 공조 협력 체제 강화의 경우 중요도 및 필요도, 각각 인식의 차이가 가장 크게 나타났다. "국민보호와 공공안전을 위한 테러방지법" 재검토의 경우 중요도와 필요도는 비교적 낮았으며, 민간 부문과의 협력의 경우 중요도와 필요도가 가장 낮은 것으로 나타났다. 학력의 경우 고졸 이하가 전문대졸보다 평균값이 높게 나타났다. 이를 통해 대테러 관련 종사자들에 대한 효율적 효과적인 개방형 통합형 대테러시스템 특성의 인식제고 교육과 "국민보호와 공공안전을 위한 테러방지법", 국제적 공조 협력 체제, 컨트롤 타워, 운영단계별 조직 기능 역할, 민간부문 협력의 5가지 구성요인별의 직무이해 및 이에 따른 적용 방안을 모색해야 할 것이다.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1996년도 춘계공동학술대회논문집; 공군사관학교, 청주; 26-27 Apr. 1996
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• pp.121-124
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• 1996

In general, cellular manufacturing system can be constructed by the following two steps. The first step forms machine cells and part families, and the second step determines cell layout based on the result of first step. Cell layout has to be considered when cell is formed becauese the result of cell formation affects it. This paper presents a cell formation algorithm and proposes an integrated mathematical model for cell formation and cell layout. The cell formation algorithm minimizes the number of exceptional element in cellular manufacturing system. New concept for similarity and incapability is introduced, based on machine-operation incidence matrix and part-operation incidence matrix. One is similarity between the machines, the other is similarity between preliminary machine cells and machines. The incapability identifies relations between machine cells and parts. In this procedure, only parts without an exceptional element are assigned to machine cell. Bottleneck parts are considered with cell layout design in an integrated mathematical model. The integrated mathematical model determines cell layout and assigns bottleneck parts to minimize the number of exceptional element and intercell moving distance, based on linearixed 0-1 integer programming. The proposed algorithm is illustrated by using numerical examples.

• 한국산업융합학회 논문집
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• 제25권5호
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• pp.799-810
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• 2022

Welding work is a production work method widely used throughout the industry, and various types of welding technologies exist. In addition, many methods are being studied to automate these welding operations using robots, but in the ship manufacturing field, welding such as painting, cutting, and grinding is also the most common operation, but the manual operation ratio is higher than in other industries. Such a high manual labor ratio in the field of ship manufacturing not only causes quality problems and production delays according to the skill of workers, but also causes problems in the supply and demand of manpower. Therefore, this paper analyzed the reason why the automation rate is low in welding work at ship manufacturing sites compared to other industries, and analyzed the production process and field environment for small and medium-sized ship manufacturing companies that repeatedly manufactured with a small quantity production method. Based on the analysis results, it is intended to propose a robot system that can easily move between workplaces and secure uniform welding quality and productivity by collaborating simple welding tasks with humans. Finally, the simulation environment is constructed and analyzed to secure the suitability of robot system application to current production site environment, work process, and productivity, rather than to develop and apply the proposed robot system. Through such pre-simulation and robot system suitability analysis, it is expected to reduce trial and error that may occur in actual field installation and operation, and to improve the possibility of robot application and positive perception of robot system at ship manufacturing sites.

• 한국콘텐츠학회논문지
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• 제6권2호
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• pp.75-83
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• 2006

항공기 체계부에서는 연구개발 과정에서 발생되는 기술자료에 대해서 데이터베이스 관리시스템을 이용하여 체계적으로 관리하는 기술자료 관리시스템을 운용하였으며, 수행중인 항공기 개발 사업에 프로젝트별로 연구개발 기술자료를 관리하였다. 그러나 사업별로 분리하여 사용자 관리 및 기술자료를 관리함에 따라 업무메모 워크플로 및 기술자료 검색 등에 문제점을 야기하였으며, 이에 따라 사업별 기술자료 관리시스템을 통합 관리할 수 있는 웹기반 통합기술정보시스템을 개발하였다. 본 시스템의 구축 및 운용으로 사용자 및 권한을 관리하여 사업별로 접근할 수 있고, 통합기술정보시스템의 통합 화면에서 각 사용자별로 필요한 업무메모 워크플로 및 기술자료 검색을 효율적으로 수행할 수 있어 사업별 기술자료 관리 및 활용 등 연구 생산성을 극대화하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.1009-1011
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• 1998

This paper presents a design of network and database structure of the integrated system for power system operational planning and analysis that will be more economical and stable of power system operation. An alias of this system is Highly Integrated Total Energy System(HITES). The Client/server model of HITES is designed as a remote data management model. The input/output-type of application programs and Oracle server is standardized. The separated user-databases from main-database strengthen security of HITES. It is plan to do that tables and relationships are defined by database designs. The connection of application program and DBMS of HITES will be tested through database design and data construction.

• The Journal of the Acoustical Society of Korea
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• 제18권2E호
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• pp.45-52
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• 1999

This paper presents the integrated speech enhancement system for hands-free mobile communication. The proposed integrated system incorporates both acoustic echo cancellation and engine noise reduction device to provide signal enhancement of desired speech signal from the echoed plus noisy environments. To implement the system, a delayless subband adaptive structure is used for acoustic echo cancellation operation. The NLMS based adaptive noise canceller then applied to the residual echo removed noisy signal to achieve the selective engine noise attenuation in dominant frequency component. Two sets of computer simulations are conducted to demonstrate the effectiveness of the system; one for the fixed acoustical environment condition, the other for the robustness of the system in which, more realistic situation, the acoustic transmission environment change. Simulation results confirm the system performance of 20-25dB ERLE in acoustic echo cancellation and 9-19 dB engine noise attenuation in dominant frequency component for both cases.

• 통합자연과학논문집
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• 제16권4호
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• pp.139-145
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• 2023

Due to changes in the distribution system and increased demand for renewable energy, interest in technology to increase the limit capacity of distributed energy grid connection using grid flexible resources is also increasing. Recently, the distribution system system is changing due to the increase in distributed power from renewable energy, and as a result, problems with the limited capacity of the distribution system, such as waiting for renewable energy to connect and increased overload, are occurring. According to the power generation facility status report provided by the Korea Power Exchange, of the total power generation capacity of 134,020 MW as of 2021, power generation capacity through new and renewable energy facilities is 24,855 MW, accounting for approximately 19%, and among them, power generation through solar power accounts for a total portion of the total. It was analyzed that the proportion of solar power generation facilities was high, accounting for 75%. In the future, the proportion of new and renewable energy power generation facilities is expected to increase, and accordingly, an efficient operation plan for the distribution system is needed. Advanced country-type NWAs that can integrate the operation and management of load characteristics for each line of the distribution system, power distribution, regional characteristics, and economic feasibility of distributed power in order to improve distribution network use efficiency without expanding distribution facilities due to the expansion of renewable energy. An integrated operating system is needed. In this study, in order to improve the efficiency of distribution network use without expanding distribution facilities due to the expansion of renewable energy, we developed a method that can integrate the operation and management of load characteristics for each line of the distribution system, power distribution, regional characteristics, and economic feasibility of distributed power. We want to develop an integrated operation system for NWAs similar to that of advanced countries.

• 항공우주시스템공학회지
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• 제13권5호
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• pp.1-8
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• 2019

최근 항공기 운용 장비는 시스템 수 및 무게, 전력 소비량 플랫폼 중복성을 줄이기 위해 기존 연합형(Federated) 구조에서 멀티코어를 이용한 모듈형(Integrated Modular) 구조로 변화하고 있다. 이러한 변화로 다수의 기능을 하나의 모듈에 통합함에 따라 디스플레이 장치를 통해 조종사에게 제공해야할 정보량이 증가하게 되었으며, 이로 인해 시스템 운용주기 내에 처리해야할 그래픽양이 증가하게 되었다. 본 논문에서는 멀티코어 시스템을 운용하기 위한 AMP(Asymmetric Multi-Processing) 방식의 파티셔닝 운용 시스템(Partition Operating System)에서 항공기 시스템의 운용주기 내에 보다 많은 그래픽을 처리하기 위해 단일코어로 처리되는 기존의 그래픽스 렌더링 엔진 구조를 멀티코어로 분산하여 처리할 수 있는 그래픽스 렌더링 엔진 분산처리방안을 제시한다.