• Structural Engineering and Mechanics
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• 제30권6호
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• pp.665-678
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• 2008

The beams components subjected to the loading such as axial, bending and cyclic thermal loads were studied in this research. The used constitutive equations are those of elasto-plasticity coupled to ductile and/or creep damage. The nonlinear kinematic hardening behavior was considered in elastoplasticity modeling. The unified damage law proposed for ductile failure and fatigue by the author of Sermage et al. (2000) and Kachanov's creep damage model applied to cyclic creep and low cycle fatigue of beams. Based on the results of the analysis, the shakedown limit loads were determined through the calculation of the residual strains developed in the beam analysis. The iterative technique determines the shakedown limit load in an iterative manner by performing a series of full coupled elastic-plastic and continuum damage cyclic loading modeling. The maximum load carrying capacity of the beam can withstand, were determined and imposed on the Bree's interaction diagram. Comparison between the shakedown diagrams generated by or without creep and/or ductile damage for the loading patterns was presented.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.262-267
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• 2004

This paper is concerned with a design method of two-degree-of-freedom controller by Coefficient Diagram Method (CDM). The two-degree-of-freedom control system satisfies both of tracking and disturbance rejection performances, but requires tuning of many parameters. By the proposed design method, these parameters can be obtained properly without any adjustment. Furthermore, the tracking and disturbance rejection performances can be simultaneously designed. The effectiveness of the proposed method is demonstrated by the simulation.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2006년도 추계학술발표대회 논문집
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• pp.115-120
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• 2006

This study concentrates on a new idea that is formulated as a creative space recognition in contemporary architecture and painting. It is stimulated from Deleuze's philosophy, which is expressed with the philosophical instrument, "Non-Representation". After discussing the concept of non-representation used in Deleuze's philosophy, case example in contemporary architecture are analysed to comparatively Investigate the relationship between the architectures by Rem Koolhaas and painting by Francis Bacon. Therefore, he founds expressions of "diagram" and "movement" in painting of F. Bacon. Diagram meansit is a power that is comprised of various points of wiew with the kind experiences that one has in life. Movement that were extracted form the Instrument in space recognition of Deleuze's panting theory were of topology, insertion of geometry, reiteration of layers, transparency and translucency, reflection effect.

• Computers and Concrete
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• 제11권6호
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• pp.515-529
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• 2013

The moment-curvature relation for simple bending is a well-studied subject and the classical moment-curvature diagram is commonly found in literature. The influence of axial forces has generally been considered as compression onto symmetrically reinforced cross-sections, thus strain at the reference fiber never has been an issue. However, when dealing with integral structures, which are usually statically indeterminate in different degrees, these concepts are not sufficient. Their horizontal elements are often completely restrained, which, under imposed deformations, leads to moderate compressive or tensile axial forces. The authors propose to analyze conventional beam cross-sections with moment-curvature diagrams considering asymmetrically reinforced cross-sections under combined influence of bending and moderate axial force. In addition a new diagram is introduced that expands the common moment-curvature relation onto the strain variation at the reference fiber. A parametric study presented in this article reveals the significant influence of selected cross-section parameters.

• 한국통신학회논문지
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• 제35권12B호
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• pp.1227-1235
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• 2010

Stateflow는 임베디드 시스템을 모델링 하는 유용한 도구로 산업 현장에서 많이 사용되고 있다. 하지만 Stateflow는 연속적인 동작이나 시간에 따른 시스템의 행동을 표현하기에 불편한 점이 있다. 한편 Timing diagram은 전자공학의 하드웨어 분야에서 시스템의 동작을 표현하기 위한 도구로 널리 사용되고 있는 도구이다. 이 도구는 연속적인 동작이나 시간에 따른 시스템의 행동을 표현하기에 편리한 장점이 있다. 그러므로 본 논문에서는 시스템의 행동을 Stateflow로 모델링 할 때 기존의 불편했던 점들을 개선하기 위해서 Stateflow 도메인에서 Stateflow 표현방식과 Timing diagram 표현방식을 통합하여 모델링 하는 방법론인 $Stateflow_{TD}$를 제안하고자 한다. 본 논문은 Stateflow 모델과 Timing diagram 모델들을 통합하는 방법과 $Stateflow_{TD}$이 가지는 장점에 대해서 설명하였을 뿐만 아니라, 두 가지 예제 시스템을 사용하여 $Stateflow_{TD}$이 유용함을 보였다.

• 한국CDE학회논문집
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• 제11권2호
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• pp.97-106
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• 2006

Voronoi diagrams have been known for numerous important applications in science and engineering including CAD/CAM. Especially, the Voronoi diagram for 3D spheres has been known as very useful tool to analyze spatial structural properties of molecules or materials modeled by a set of spherical atoms. In this paper, we present two algorithms, the edge-tracing algorithm and the region-expansion algorithm, for constructing the Voronoi diagram of 3D spheres and applications to protein structure analysis. The basic scheme of the edge-tracing algorithm is to follow Voronoi edges until the construction is completed in O(mn) time in the worst-case, where m and n are the numbers of edges and spheres, respectively. On the other hand, the region-expansion algorithm constructs the desired Voronoi diagram by expanding Voronoi regions for one sphere after another via a series of topology operations, starting from the ordinary Voronoi diagram for the centers of spheres. It turns out that the region-expansion algorithm also has the worst-case time complexity of O(mn). The Voronoi diagram for 3D spheres can play key roles in various analyses of protein structures such as the pocket recognition, molecular surface construction, and protein-protein interaction interface construction.

• 한국산업정보학회논문지
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• 제5권3호
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• pp.87-93
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• 2000

근래의 소프트웨어 관련업계에서는 소프트웨어 개발 및 관리에 있어 소프트웨어 아키텍처를 중심으로 생산성 및 품질의 극대화를 추구하고 있다. 또한 소프트웨어 컴포넌트 관련 기술 및 컴포넌트 기반 소프트웨어 개발 방법론에 대한 연구도 활발히 진행중이며, 많은 응용기술들이 나오고 있다. 소프트웨어 아키텍처는 소프트웨어를 컴포넌트로 구성하고 그 사이의 상호작용을 커넥터를 이용해 기술함으로서 전체적인 구조를 분석하고 유지하는데 필수적인 요소로 고려된다. 본 연구에서 제안하는 소프트웨어 모델링 기법은 Happy Work라는 모델링 도구를 사용하여 소프트웨어 구조를 기술하는 Happy Work Language를 생성한다. 그 과정에서 System Context Diagram, Component Diagram, Component Sequence Diagram과 같이 세 가지 다이어그램이 사용되며, User, System, Component, Connector와 같은 네 가지 Elements로 구성된다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2009년도 추계학술대회 논문집
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• pp.797-803
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• 2009

The accurate prediction of dynamic characteristics of high speed rotors, such as gas turbines, is important to avoid the possibility of operating the machinery near the critical speeds or unstable speed regions. However, the dynamic analysis methods and softwares for gas turbines have been developed in the process of producing many gas turbines by manufacturers and most of them have seldom been disclosed to the public. Recently, commercial FEM softwares, such as SAMCEF, ANSYS and NASTRAN, started supporting some rotordynamics analysis modules based on 3-D finite elements. In this paper, the dynamic analysis method using commercial S/W, especially ANSYS, is attempted for the small-size gas turbine engine rotor, and the analysis capability and limitations of its rotordyamics module are evaluated for further improvement of the module. As the preliminary procedure, the rotordyamic analysis capability of ANSYS was tested and evaluated with the reference models of the well-known dynamics. The limitations in application of the rotordynamics module were then identified. Under the current capability and limitations of ANSYS, it is shown that Lee diagram, a new frequency-speed diagram enhanced with the concept of $H{\infty}$ in rotating machinery, can be indirectly obtained from FRFs computed from harmonic response analysis of ANSYS. Finally, it is demonstrated based on the modeling and analysis method developed in the process of the S/W verification that the conventional Campbell diagram, Lee diagram, mode shapes and critical speeds of the small-size gas turbine engine rotor can be computed using the ANSYS rotordynamics module.

• 한국소음진동공학회논문집
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• 제20권1호
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• pp.36-44
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• 2010

The accurate prediction of dynamic characteristics of high speed rotors, such as gas turbines, is important to avoid the possibility of operating the machinery near the critical speeds or unstable speed regions. However, the dynamic analysis methods and softwares for gas turbines have been developed in the process of producing many gas turbines by manufacturers and most of them have seldom been disclosed to the public. Recently, commercial FEM softwares, such as SAMCEF, ANSYS and NASTRAN, started supporting some rotordynamics analysis modules based on 3-D finite elements. In this paper, the dynamic analysis method using commercial S/W, especially ANSYS, is attempted for the small-size gas turbine engine rotor, and the analysis capability and limitations of its rotordyamics module are evaluated for further improvement of the module. As the preliminary procedure, the rotordyamic analysis capability of ANSYS was tested and evaluated with the reference models of the well-known dynamics. The limitations in application of the rotordynamics module were then identified. Under the current capability and limitations of ANSYS, it is shown that Lee diagram, a new frequency-speed diagram enhanced with the concept of $H{\infty}$ in rotating machinery, can be indirectly obtained from FRFs computed from harmonic response analysis of ANSYS. Finally, it is demonstrated based on the modeling and analysis method developed in the process of the S/W verification that the conventional Campbell diagram, Lee diagram, mode shapes and critical speeds of the small-size gas turbine engine rotor can be computed using the ANSYS rotordynamics module.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제31권3호
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• pp.257-277
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• 2017

본 연구의 주된 목적은 크게 두 가지로 나눌 수 있다. 첫째, 최근 수학적 모델링이 강조되는 상황에서 보로노이 다이어그램과 들로네 삼각분할을 주제로 영재교육을 위한 수학적 모델링 프로그램을 개발하는 것이다. 둘째, 본 연구에서 개발한 수학적 모델링 프로그램을 실제 영재교육 수업에 적용한 결과를 분석하여 수학적 모델링 수업을 설계하는 현직교사와 융합형 영재프로그램을 개발하는 영재교사에게 도움을 주고자 한다.