• Journal of the Korean Ceramic Society
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• v.53 no.2
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• pp.150-161
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• 2016

The conventional brick-layer model is not satisfactory either in theory or in practice for the description of dispersive responses of polycrystalline solid electrolytes with current-constriction effects at the grain boundaries. Parallel networks of complex dielectric functions have been shown to successfully describe the AC responses of polycrystalline sodium conductors over a wide temperature and frequency range using only around ten model parameters of well-defined physical significance. The approach can be generally applied to many solid electrolyte systems. The present work illustrates the approach by simulation. Problems of bricklayer model analysis are demonstrated by fitting analysis of the simulated data under experimental conditions.

• Structural Engineering and Mechanics
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• v.5 no.6
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• pp.679-689
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• 1997

The damage of concrete subjected to multiaxial complex loading involves strong anisotropy due to its highly heterogeneous nature and the geometrically anisotropic characteristic of the microcracks. A comprehensive description of concrete damage is proposed by introducing a fourth-order anisotropic damage tenser. The evolution of damage is assumed to be related to the principal components of the current states of stress and damage. The unilateral effect of damage due to the closure and opening of microcracks is taken into account by introducing projection tensors that are also determined by the current state of stress. The proposed damage model considers the different kinds of damage mechanisms that result in different failure modes and different patterns of microdefects that cause different unilateral effects. This damage model is embedded in a thermomechanically consistent constitutive equation in which hardening and the triaxial compression caused shear-enhanced compaction can also be taken into account. The validity of the proposed model is verified by comparing theoretical and experimental results of plain and steel fiber reinforced concrete subjected to complex triaxial stress histories.

• Journal of KSNVE
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• v.10 no.3
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• pp.410-422
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• 2000

This paper proposes a model of standardized noise map in korea, The standardization of noise map is accomplished by standardizing the way of map description and by applying international noise mapping criteria to Korean environment. The proposed model can be an useful star or the production of national standardized noise map in Korea.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.05a
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• pp.173-174
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• 2004

• Proceedings of the Korean Information Science Society Conference
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• 2006.10c
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• pp.396-401
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• 2006

아키텍처에 대한 기술은 아키텍처 평가와 검증을 위해서 반드시 필요하다. 아키텍처 기술(Architecture Description)을 위해서 아키텍처 기술언어, 아키텍처 모델에 대한 다양한 연구들이 있었다. IEEE-1471의 아키텍처 기술을 위한 개념적 모델이 아키텍처 기술에 대한 일반적인 모델로 제시되었고 이후에 아키텍처 기술에 대한 새로운 요소들이 제시되었다. 그러므로 IEEE-1471의 개념적 모델은 새로운 요소들의 개념 사이에 혼란이 존재한다. 본 논문에서는 IEEE-1471의 개념적 모델을 바탕으로 이후에 제시된 세 가지 요소를 추가함으로써 IEEE-1471의 개념적 모델을 확장하고자 한다.

• Journal of Korean Library and Information Science Society
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• v.48 no.4
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• pp.129-151
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• 2017

Information modeling that is broadly applied in digital archiving process privides conceptual process that can be used to guide the creation of descriptions for the objects of preservation. However, it has faced with the limitations on substantially applying to the creation of preservation metadata records. This research proposes the concept of Resource Cluster in order to address these problems and efficiently describe the objects of preservation during digital archiving process. It also constructed Preservation Description Framework (PDF) based on RDF in order to substantially manifest preservation descriptions. This framework combines the structure of OAIS Reference Model and Functional Requirements for Bibliographic Records (FRBR) and can be an alternative approach to the creation of preservation metadata in more efficient and effective ways.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.11 no.8
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• pp.3935-3949
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• 2017

In this paper, a novel multiple description image coding (MDC) scheme is proposed, which is based on the characteristics of the human visual model. Due to the inherent characteristics of human vision, the human eye can only perceive the change of the specific thresholds, that is, the just noticeable difference (JND) thresholds. Therefore, JND model is applied to improve MDC syetem. This paper calculates the DCT coefficients firstly, and then they are compared with the JND thresholds. The data that is less than the JND thresholds can be neglected, which will improve the coding efficiency. Compared with other existing methods, the experimental results of the proposed method are superior.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.318-321
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• 2009

Transformation plasticity is that when a phase transformation of ferrous or non-ferrous alloys progresses even under an extremely small applied stress compared with a yield stress of the material, a permanent deformation occurs. One of widely accepted description for the transformation was proposed by Greenwood and Johnson [1]. Their description is based on an assumption that a weaker phase of an ideal plastic material could deform plastically to accommodate the externally applied stress and the internal stress caused by the volumetric change accompanying the phase transformation. In this study, an implicit finite element model was developed to simulate the deformation behavior of a low carbon steel during phase transformation. The finite element model was coupled with a phase field model, which could simulate the kinetics for ferrite to austenite transformation of the steel. The thermo-elasto-plastic constitutive equation for each phase was adopted to confirm the weaker phase yielding, which was proposed by Greenwood and Johnson [1]. From the simulation, the origin of the transformation plasticity was quantitatively discussed comparing with the other descriptions of it.

• Proceedings of the IEEK Conference
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• 2003.07d
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• pp.1403-1406
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• 2003

This paper presents a user preference description for graphics contents that is developed in the process of the MPEG-21 DIA(Digital Item Adaptation) standard. The description scheme in this paper is proposed by the authors and adopted in the current AM (Adaptation Model) document of the MPEG-21 DIA. The goal of MPEG-21 standard is providing a multimedia framework that Provides augmented and transparent use of digital contents across various networks and terminals fur the life cycle of digital contents. DI (Digital Item) is a standardized basic unit of digital contents for transaction in the scope of MPEG-21. DIA contains both media resources and metadata including rights information.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.72-75
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• 2000

This paper presents a simulation study on the description of the motion and the control of an active catheter actuator with multi-link structure actuated by Shape Memory Alloy(SMA). The model of an active catheter adopted in this paper has 3 links, and the individual links are composed of 3 micro coils of SMA for the omni-directional motion. In order to analyze the motions of multi-link structure, 3-dimensional kinematics description is presented. Also, the motion control of the end point of an active catheter using simple Neural Network is shown based on GUI(Graphic User Interface) system.