• Structural Engineering and Mechanics
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• 제44권5호
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• pp.681-704
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• 2012

The dynamic response of Euler-Bernoulli beams to resonant harmonic moving loads is analysed. The non-dimensional form of the motion equation of a beam crossed by a moving harmonic load is solved through a perturbation technique based on a two-scale temporal expansion, which permits a straightforward interpretation of the analytical solution. The dynamic response is expressed through a harmonic function slowly modulated in time, and the maximum dynamic response is identified with the maximum of the slow-varying amplitude. In case of ideal Euler-Bernoulli beams with elastic rotational springs at the support points, starting from analytical expressions for eigenfunctions, closed form solutions for the time-history of the dynamic response and for its maximum value are provided. Two dynamic factors are discussed: the Dynamic Amplification Factor, function of the non-dimensional speed parameter and of the structural damping ratio, and the Transition Deamplification Factor, function of the sole ratio between the two non-dimensional parameters. The influence of the involved parameters on the dynamic amplification is discussed within a general framework. The proposed procedure appears effective also in assessing the maximum response of real bridges characterized by numerically-estimated mode shapes, without requiring burdensome step-by-step dynamic analyses.

• 대한산업공학회지
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• 제38권4호
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• pp.258-261
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• 2012

In this paper, I propose a new asset allocation framework to cope with the dynamic nature of the financial market. The investment performance can be much improved by protecting the capital from the market crashes, and such crashes can be pre-identified with high probabilities by regime detection analysis via a specialized unsupervised machine learning technique.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2013년도 춘계학술대회 논문집
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• pp.759-760
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• 2013

• Journal of the Korean Data and Information Science Society
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• 제6권2호
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• pp.29-39
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• 1995

A model used in the past may be altered at will in modeling for the future. For this situation, the multiprocess dynamic model provides a general framework. In this paper we consider the multiprocess discount normal model with parameters having a time dependent non-linear structure. This model has nice properties such as insensitivity to outliers and quick reaction to abrupt changes of pattern.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 정기총회 및 추계학술대회 논문집 학회본부
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• pp.310-313
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• 1993

A design of stabilizing supervisory controller for discrete event dynamic systems(DEDS) is investigated in this paper. The notion of system stability is introduced for the supervisory control and the stable behavior is defined. A framework of stabilizing supervisory controller, which controls a given system to have stable behavior. is formulated and a design method is proposed for the stabilizing, supervisory controller.

• Steel and Composite Structures
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• 제2권2호
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• pp.113-128
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• 2002

The performance of steel MRF with rigid connections, proportioned by adopting different capacity design criteria, is evaluated in order to highlight the effectiveness of static non-linear procedure in predicting the structural seismic behavior. In the framework of the performance-based design, some considerations are made on the basis of the results obtained by both dynamic time histories and push-over analyses, particularly with reference to the damage level and the structure ability to withstand a strong earthquake.

• 소성∙가공
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• 제13권7호
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• pp.600-607
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• 2004

This paper addresses a viscoplastic constitutive model that allows a consistent way of modeling positive and negative rate sensitivities of flow stress concerned with dynamic strain aging. Based on the concept of continuum mechanics, a phenomenological constitutive model includes the use of a yield surface within the framework of unified viscoplasticity theory. To model negative rate sensitivity, rate-dependent back stress is introduced and flow stress in fully developed inelastic deformation regime is thus decomposed into the plastic contribution of rate independency and the viscous one of rate dependency.

• Structural Engineering and Mechanics
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• 제5권2호
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• pp.209-220
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• 1997

The dynamic equations for an arbitrary cluster comprising rigid spheres or assemblies of spheres (subclusters) encountered in granular-type systems are considered. The system is treated within the framework of multibody dynamics. It is shown that for an arbitrary cluster topology the governing equations can be given in an explicit scalar from. The derivation is based on the D'Alembert principle, on inertial coordinate system for each body and direct utilization of the path matrix describing the topology. The scalar form of the equations is important in computer simulations of flow of granular-type materials. An illustrative example of a three-body system is given.

• Journal of Computing Science and Engineering
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• 제2권4호
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• pp.375-393
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• 2008

The dynamic cast operation allows flexibility in the design and use of data management facilities in object-oriented programs. Dynamic cast has an important role in the implementation of the Data Management Services (DMS) of the Mission Data System Project (MDS), the Jet Propulsion Laboratory's experimental work for providing a state-based and goal-oriented unified architecture for testing and development of mission software. DMS is responsible for the storage and transport of control and scientific data in a remote autonomous spacecraft. Like similar operators in other languages, the C++ dynamic cast operator does not provide the timing guarantees needed for hard real-time embedded systems. In a recent study, Gibbs and Stroustrup (G&S) devised a dynamic cast implementation strategy that guarantees fast constant-time performance. This paper presents the definition and application of a cosimulation framework to formally verify and evaluate the G&S fast dynamic casting scheme and its applicability in the Mission Data System DMS application. We describe the systematic process of model-based simulation and analysis that has led to performance improvement of the G&S algorithm's heuristics by about a factor of 2. In this work we introduce and apply a library for extracting semantic information from C++ source code that helps us deliver a practical and verifiable implementation of the fast dynamic casting algorithm.

• 인터넷정보학회논문지
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• 제8권6호
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• pp.55-73
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• 2007

정보통신 환경이 유비쿼터스 환경으로 발전하면서 이종의 디바이스간의 연동 기술의 필요성이 크게 증가하고 있으며, 이를 해결하기 위한 하나의 대안으로 웹서비스가 주목받고 있다. 최근 디바이스 연동을 위한 선언적인 ICA(Event-Condition-Action) 룰 기반의 프레임워크가 제안되었으며, 이를 WS-ECA(Web Services-ECA) 프레임워크라 한다. 이는 웹서비스를 기반으로 디바이스간의 연동을 선언적으로 정의하는 ICA 기반 룰 언어를 제안하고, 정의된 룰을 기반으로 디바이스간의 연동을 수행할 수 있는 프레임워크를 제안하였다. 본 논문에서는 본 프레임워크가 유비쿼터스 환경의 동적인 특성을 효과적으로 지원하기 위해 반드시 필요한 컴포넌트간의 프로토콜 및 프레임워크 내의 서비스/이벤트 기술을 위한 WSDL 확장 방법을 제안한다.