• Structural Engineering and Mechanics
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• 제14권2호
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• pp.223-236
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• 2002

The main objective of the present paper is to address a formal procedure for orthotropic steel plates design. The theme of the proposed approach is to recast the design procedure into a mathematical programming model. The objective function to be optimized is the total weight of the structure. The total weight is function of its layout parameters and structural element design variables. Mean while the proposed approach takes into consideration the strength and rigidity criteria in addition to other dimensional constraints. A nonlinear programming model is developed which consists of a nonlinear objective function and a set of implicit/explicit nonlinear constraints. A transformation method is adopted for minimization strategy, where the primal model constrained problem is transformed into a sequence of unconstrained minimization models. The search strategy is based on the well-known Fletcher/Powell algorithm. The finite element technique is adopted for discretization and analysis strategies. Mindlin theory is selected to simulate the finite element model and a selective reduced integration scheme is exploited to avoid a shear lock problem.

• Journal of Electrical Engineering and Technology
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• 제6권1호
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• pp.25-31
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• 2011

The purpose of power system maintenance is to prevent equipment failure. The maintenance strategy should be designed to balance costs and benefits because frequent maintenance increases cost while infrequent maintenance can also be costly due to electricity outages. This paper proposes maintenance modeling of a power distribution system using reliability centered maintenance (RCM). The proposed method includes comprehensive equipment modeling and impact analysis to evaluate the effect of equipment faults. The problem of finding the optimum maintenance strategy is formulated in terms of dynamic programming. The applied power system is based on the RBTS Bus 2 model, and the results demonstrate the potential for designing a maintenance strategy using the proposed model.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제14권8호
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• pp.753-757
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• 2008

본 논문은 그리드 환경에서 동전계획법을 위한 새로운 스케줄링 정책을 제안한다. 이 스케줄링 정책의 특징은 동적 테이블의 지역성을 고려하여 테이블을 분할하고, 네트워크 지연이 최소인 노드에 작업을 할당함으로써 작업의 실행시간을 단축하는 것이다. 또한 최적의 병행성을 얻기 위해 분산 하향식으로 동적 테이블을 구성한다 시뮬레이션을 통하여 제안하는 그리드 스케줄링 정책이 그리드 환경의 성능 향상 면에서 기존의 분기-한정(branch-bound) 알고리즘에 비해 더 효과적임을 보인다

• 한국자동차공학회논문집
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• 제23권2호
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• pp.239-245
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• 2015

In order to control the hybrid power system efficiently, the knowledge for the required load of the system is important. The agricultural tractor performs various farm works such as plow, rotary, and baler. When it performs rotary tillage and baler operation, the generated work load is analyzed. To analyze trend of work load, moving average technique is applied to the measurement data. Optimal control inputs for the two works are obtained from simulation using the dynamic programming. The novel fundamental control strategy for parallel hybrid tractor called Max. SOC is proposed.

• Structural Engineering and Mechanics
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• 제3권4호
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• pp.373-382
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• 1995

The weighting strategy has received a great attention and has been widely applied to multicriterion optimization. This gaper examines a global criterion method (GCM) with the weighting objectives strategy in fuzzy structural engineering problems. Fuzziness of those problems are in their design goals, constraints and variables. Most of the constraints are originated from analysis of engineering mechanics. The GCM is verified to be equivalent to fuzzy goal programming via a truss design. Continued and mixed discrete variable spaces are presented and examined using a fuzzy global criterion method (FGCM). In the design process a weighting parameter with fuzzy information is introduced into the design and decision making. We use a uniform machine-tool spindle as an illustrative example in continuous design space. Fuzzy multicriterion optimization in mixed design space is illustrated by the design of mechanical spring stacks. Results show that weighting strategy in FGCM can generate both the best compromise solution and a set of Pareto solutions in fuzzy environment. Weighting technique with fuzziness provides a more relaxed design domain, which increases the satisfying degree of a compromise solution or improves the final design.

• Journal of applied mathematics & informatics
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• 제30권1_2호
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• pp.1-14
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• 2012

In this paper, the problem of determining the optimal car-deriving strategy has been examined. In order to find the optimal driving strategy, we have modified a method based on measure theory. Further, we demonstrate that the modified method is an efficient and practical algorithm for dealing with optimal control problems in a canonical formulation.

• Journal of Information Technology Applications and Management
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• 제23권2호
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• pp.61-80
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• 2016

The wireless mesh network (WMN) is a next-generation technology for data networking that has the advantage in cost and the flexibility in its construction because of not requiring the infra-structure such as the ethernet. This paper focuses on the optimal link scheduling problem under the wireless mesh network to effectuate real-time streaming by using the constraint programming. In particular, Under the limitation of half-duplex transmission in wireless nodes, this paper proposes a solution method to minimize the makespan in scheduling packet transmission from wireless nodes to the gateway in a WMN with no packet transmission conflicts due to the half-duplex transmission. It discusses the conflicts in packet transmission and deduces the condition of feasible schedules, which defines the model for the constraint programming. Finally it comparatively shows and discusses the results using two constraint programming solvers, Gecode and the IBM ILOG CP solver.

• 품질경영학회지
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• 제30권3호
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• pp.150-167
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• 2002

Normative theory suggests that control systems should be designed to complement management's objectives and strategies. However, few empirical studies have focused on how control systems have been modified to complement new manufacturing techniques, such as zero-defect strategy. The major purpose of this study is to examine the effects of the attributes of quality strategy and control system on performance. The previous studies have subdivided quality strategy into the ECL(economic conformance level) and ZD(zero-defect) strategy. To accomplish the purpose, this study empirically analysed the data based on the questionnaires from manufacturing department personnel of 67 Korean companies. The major results are as follows. The companies that had implemented the ZD strategy and its control system outperformed the companies that had implemented ECL strategy. Also, the ZD strategy differs from ECL strategy in control system, the criteria of performance evaluation and feedback frequence variable. There is no difference in quality performance monitoring and communication variable. From this results, although many companies have strived for continuous improvement of quality, it was restricted in improvement activities that dont's required much investment cost, quality performance monitoring and communication.

• 한국콘텐츠학회논문지
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• 제16권11호
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• pp.731-741
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• 2016

출범한 지 5년이 지나고 있는 종합편성채널은 생방송 위주의 생산체계를 구축하고 있다. 생방송 비율이 높다는 것은 뉴스와 시사프로그램의 높은 비중을 의미하는데, 특히 시사프로그램의 생방송 생산방식이 지니는 의미는 중요하다. 종합편성채널의 생방송 시사프로그램은 뉴스보다 속보성에서 앞서면서 시청자들을 그 사건에 참여하는 것처럼 느끼게 하는 동시에 해설, 토론, 추론 등이 뒤섞이는 특징을 지닌다. 생방송 비중이 높은 종합편성채널들은 스튜디오 제작 스태프들을 보유하고 있는 자회사를 설립해 뉴스와 시사프로그램을 생산하고 있으며, 연출자들은 자회사에 소속되어 있다. 종합편성채널들은 재방송 전략을 통해 전체 시청률을 향상시키기 위하여 본방송 시기와 관계없이 재방프로그램을 선정하고 있다. 이는 새로운 프로그램을 개발하기보다는 성공한 프로그램들을 장기적으로 제작하는 생산방식에 영향을 미치며, 노출 다양성 제고를 제한하는 요인으로 작용하고 있다.

• 한국콘텐츠학회논문지
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• 제12권5호
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• pp.103-112
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• 2012

본 연구는 과학대중화에 있어 중요한 역할을 수행하고 있는 국내 과학전문채널인 'YTN 사이언스'가 시청률, 콘텐츠, 제작비의 부족을 드러내고 있다는 문제인식 하에, 우선 현행 국내 과학전문채널의 프로그램 편성과 운영현황, 홍보 전략을 탐색적으로 확인하였다. 다음으로 미국(디스커버리 채널, 내셔널지오그래픽 채널), 영국(BBC Knowledge), 일본(사이언스채널), 중국(CCTV 10) 등 해외 각국의 과학방송채널 특히, 중요 프로그램들을 분석하여 향후 국내 과학전문채널에 활용 및 접목시킬 수 있는 가능성을 모색하였다. 이러한 현실진단과 해외사례분석을 통해 다양한 시사점을 확인하였으며, 이를 통해 제시될 수 있는 콘텐츠 개발 및 홍보전략은 다음과 같다. 우선 콘텐츠가치 제고를 위한 편성전략의 수정이 필요한 바, 타깃 시청집단과 시청자 라이프스타일을 고려한 편성 재조정, 줄띠편성(Stripping)을 통한 시청습관화 전략, 프라임타임(prime time)대의 전략 프로그램 배치가 필요할 것이다. 다음으로 콘텐츠제작 및 활용전략 측면에서는 콘텐츠 제작의 이중적 전략(지식전달, 흥미전달의 두 분야로의 구분), 프로그램의 대표 캐릭터의 기획과 활용, 한국적 과학기술소재의 선택, SNS와의 전략적 연계, 소재의 다변화와 심층화, OSMU 활성화 전략이 요구될 것이다. 마지막으로 홍보전략 차원에서는 과학관련 행사 개최와 중계방송을 통한 채널 인지도 제고, 잡지 및 단행본 발간 등 인쇄매체로의 확장을 통한 홍보전략 수행, 온라인/모바일 홍보 전략의 강화 등을 제시할 수 있겠다.