• 한국컴퓨터정보학회논문지
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• 제14권12호
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• pp.33-40
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• 2009

다중에이전트 시스템의 분석에 중요한 시간, 지식, 그리고 전략에 관한 개념들을 구체화하기 위해 번역시스템(Interpreted Systems)과 ATL및 ATEL을 살펴보고, 특히 ATEL의 문제점, 즉 하나의 에이전트는 그 자신의 상태에 대해 확실한 정보를 갖지 못하더라도 전략을 구성함에 있어서 전체 시스템의 현재 상태에 접근할 수 있으며, 또한 ATEL의 불명확한 행위들에 대한 표현은 일반적인 상황을 모델링하는 것을 어렵게 하는 문제점들을 해결하기 위한 방안으로 게임이론의 서브게임 완전한 나쉬평형 (subgame perfect Nash equilibrium)에 기초한 전략적 제한(strategic constraints)을 그 문제의 해결책으로 제안한다. 또한, 전략적 제한에 기초한 번역시스템을 다중에이전트 시스템에서의 모델체킹 (model checking)을 위한 하나의 방법으로 제안한다.

• 한국전산유체공학회지
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• 제13권4호
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• pp.114-125
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• 2008

Current state and perspective of DNS of turbulence and turbulent combustion are discussed with feature trend of the fastest supercomputer in the world. Based on the perspective of DNS of turbulent combustion, possibility of perfect simulations of IC engine is shown. In 2020, the perfect simulation will be realized with 30 billion grid points by 1EXAFlops supercomputer, which requires 4 months CPU time. The CPU time will be reduced to about 4 days if several developments were achieved in the current fundamental researches. To shorten CPU time required for DNS of turbulent combustion, two numerical methods are introduced to full-explicit full-compressible DNS code. One is compact finite difference filter to reduce spatial resolution requirements and numerical oscillations in small scales, and another is well-known point-implicit scheme to avoid quite small time integration of the order of nanosecond for fully explicit DNS. Availability and accuracy of these numerical methods have been confirmed carefully for auto-ignition, planar laminar flame and turbulent premixed flames. To realize DNS of IC engine with realistic kinetic mechanism, several DNS of elemental combustion process in IC engines has been conducted.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 학술대회
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• pp.359-366
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• 2008

Current state and perspective of DNS of turbulence and turbulent combustion are discussed with feature trend of the fastest supercomputer in the world. Based on the perspective of DNS of turbulent combustion, possibility of perfect simulations of IC engine is shown. In 2020, the perfect simulation will be realized with 30 billion grid points by 1EXAFlops supercomputer, which requires 4 months CPU time. The CPU time will be reduced to about 4 days if several developments were achieved in the current fundamental researches. To shorten CPU time required for DNS of turbulent combustion, two numerical methods are introduced to full-explicit full-compressible DNS code. One is compact finite difference filter to reduce spatial resolution requirements and numerical oscillations in small scales, and another is well-known point-implicit scheme to avoid quite small time integration of the order of nanosecond for fully explicit DNS. Availability and accuracy of these numerical methods have been confirmed carefully for auto-ignition, planar laminar flame and turbulent premixed flames. To realize DNS of IC engine with realistic kinetic mechanism, several DNS of elemental combustion process in IC engines has been conducted.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년 추계학술대회논문집
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• pp.359-366
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• 2008

Current state and perspective of DNS of turbulence and turbulent combustion are discussed with feature trend of the fastest supercomputer in the world. Based on the perspective of DNS of turbulent combustion, possibility of perfect simulations of IC engine is shown. In 2020, the perfect simulation will be realized with 30 billion grid points by 1EXAFlops supercomputer, which requires 4 months CPU time. The CPU time will be reduced to about 4 days if several developments were achieved in the current fundamental researches. To shorten CPU time required for DNS of turbulent combustion, two numerical methods are introduced to full-explicit full-compressible DNS code. One is compact finite difference filter to reduce spatial resolution requirements and numerical oscillations in small scales, and another is well-known point-implicit scheme to avoid quite small time integration of the order of nanosecond for fully explicit DNS. Availability and accuracy of these numerical methods have been confirmed carefully for auto-ignition, planar laminar flame and turbulent premixed flames. To realize DNS of IC engine with realistic kinetic mechanism, several DNS of elemental combustion process in IC engines has been conducted.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권7호
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• pp.3353-3370
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• 2016

The way of combination of Product Perfect Codes (PPCs) is based on the theory of short codes constructing long codes. PPCs have larger embedding rate than Hamming codes by expending embedding columns in a coding block, and they have been proven to enhance the performance of the F₅ steganographic method. In this paper, the proposed modified product codes called MPCs are introduced as an efficient way to embed more data than PPCs by increasing 2^r₂-1-r₂ embedding columns. Unlike PPC, the generation of the check matrix H in MPC is random, and it is different from PPC. In addition a simple solving way of the linear algebraic equations is applied to figure out the problem of expending embedding columns or compensating cases. Furthermore, the MPCs over ℤ₄ have been proposed to further enhance not only the performance but also the computation speed which reaches O(n₁+σ). Finally, the proposed ℤ₄-MPC intends to maximize the embedding rate with maintaining less distortion , and the performance surpasses the existing improved product perfect codes. The performance of large embedding rate should have the significance in the high-capacity of covert communication.

• International Journal of Aeronautical and Space Sciences
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• 제7권1호
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• pp.13-26
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• 2006

When the stagnation temperature of a perfect gas increases, the specific heat for constant pressure and ratio of the specefic heats do not remain constant any more and start to vary with this temperature. The gas remains perfect: its state equation remains always valid, with exception that it will be named by calorically imperfect gas. The aim of this research is to develop the relations of the necessary thermodynamics and geometrical ratios. and to study the supersonic flow at high temperature. lower than the threshold of dissociation. The results are found by the resolution of nonlinear algebraic equations and integration of complex analytical functions where the exact calculation is impossible. The dichotomy method is used to solve the nonlinear equation. and the Simpson algorithm for the numerical integration of the found integrals. A condensation of the nodes is used. Since. the functions to be integrated have a high gradient at the extremity of the interval of integration. The comparison is made with the calorifcally perfect gas to determine the error made by this last. The application is made for the air in a supersonic nozzle.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.18-21
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• 2001

In this paper, some geometric condition for a stochastic nonlinear system and an adaptive control method for minimum-phase stochastic nonlinear system using neural network me provided. The state feedback linearization is widely used technique for excluding nonlinear terms in nonlinear system. However, in the stochastic environment, even if the minimum phase linear system derived by the feedback linearization is not sufficient to be controlled robustly. In the viewpoint of that, it is necessary to make an additional condition for observation of nonlinear stochastic system, called perfect filtering condition. In addition, on the above stochastic nonlinear observation condition, I propose an adaptive control law using neural network. Computer simulation shoo's that the stochastic nonlinear system satisfying perfect filtering condition is controllable and the proposed neural adaptive controller is more efficient than the conventional adaptive controller.

• 건축역사연구
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• 제16권3호
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• pp.21-38
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• 2007

If we take account of the 'Architectural Tradition' which aims a construction of better environment, we can see that this tradition has ended historically toward Utopia. It is a continual trend from ancient Greece to contemporary epoch in each transitional periods and especially in the Renaissance Era. Utopia is an ideal commonwealth in which inhabitants exist under perfect conditions, ideally perfect places or state of things. The plans of utopia are complete projects of image, its goal is an social, political and economical improvement according to the eras. Its plans are characterized by rigid geometrical pattern as circle and square, which contain generally center axis symmetry enclosure. Recent urban and architectural circumstances no longer reflect utopian visions. Since the latter of the 20th century, it appears dystopia on the contrary. Therefore, the utopian ideal city and architecture describes characteristics of the era unlike the continuity of its concept.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.18-18
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• 2000

In this paper, some geometric condition for a stochastic nonlinear system and an adaptive control method for minimum-phase stochastic nonlinear system using neural network are provided. The state feedback linearization is widely used technique for excluding nonlinear terms in nonlinear system. However, in the stochastic environment, even if the minimum phase linear system derived by the feedback linearization is not sufficient to be controlled robustly. the viewpoint of that, it is necessary to make an additional condition for observation of nonlinear stochastic system, called perfect filtering condition. In addition, on the above stochastic nonlinear observation condition, I propose an adaptive control law using neural network. Computer simulation shows that the stochastic nonlinear system satisfying perfect filtering condition is controllable and the proposed neural adaptive controller is more efficient than the conventional adaptive controller

• Nuclear Engineering and Technology
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• 제25권3호
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• pp.394-402
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• 1993

원자력 발전소 운전원에게 발전소 상태를 정확히 알려주는 완벽한 신호가 원자력 발전소 전체의 가용도와 경제성에 얼마만한 영향을 주는가에 대한 정량적인 분석이 이 논문에서 수행되어졌다. 이 분석을 위한 기본 모델들이 개발되어졌고 이 모델들은 발전소가 정상상태에서 비정상상태로 바뀌어갈때 운전원이 발전소가 완전히 비정상상태로 가기전에 발전소를 정상상태로 회복시키는 것에 완벽한 발전소 신호가 얼마만큼 영향을 주는가를 정량화 하였다. 또한 이러한 완벽한 신호가 경제적으로 얼마만큼의 이득을 주는가도 정량화 하였다. 이 모델 적용의 대상으로는 응축 및 주급수 시스템을 선정하였다.