• Structural Engineering and Mechanics
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• v.30 no.6
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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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• 2004.08a
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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.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2006.11a
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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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• v.11 no.6
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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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.12B
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• pp.1227-1235
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• 2010

Stateflow is a useful system modeling tool, which is frequently used in industry. But Stateflow has defects when users are trying to describe consecutive behaviors or a system's temporal behaviors. Timing diagram, on the other hand, is a widely used tool of explaining behaviors of a hardware system in electronics. This tool has a merit when specifying consecutive behaviors and temporal behaviors of a system. Thus, this paper suggests $Stateflow_{TD}$, the unified modeling methodology in Stateflow domain integrating Stateflow with Timing diagram in order to improve the shortcomings of Stateflow. This paper not only explains a technique of integrating both a Stateflow model and Timing diagram models, and describes advantages of what $Stateflow_{TD}$ formalism has, but also shows its convenience using two example systems.

• Korean Journal of Computational Design and Engineering
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• v.11 no.2
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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.

• Journal of Korea Society of Industrial Information Systems
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• v.5 no.3
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• pp.87-93
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• 2000

Recently Software Industry has tended to enhance the productivity and quality with using the software architecture in software development and administration. The research of software component technique and software development methodology are just doing and making many applications. The software architecture is considered as the essential element for analyzing and maintaining the entire structure with organizing the software into components and describing the relations with connectors. The software modeling methodology that we propose is generating Happy Work Language describing the software structure with the modeling tool as Happy Work. We can use System Context Diagram, Component Diagram, Component Sequence Diagram, and they are composed of four Elements as Users, Systems, Components, Connectors.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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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.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.1
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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.

• Communications of Mathematical Education
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• v.31 no.3
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• pp.257-277
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• 2017

The purpose of this research is divide into two kinds. First, develop the mathematical modeling program for mathematically gifted students focused on Voronoi diagram and Delaunay triangulation, and then gifted teachers can use it in the class. Voronoi diagram and Delaunay triangulation are Spatial partition theory use in engineering and geography field and improve gifted student's mathematical connections, problem solving competency and reasoning ability. Second, after applying the developed program to the class, I analyze gifted student's core competency. Applying the mathematical modeling program, the following findings were given. First, Voronoi diagram and Delaunay triangulation are received attention recently and suitable subject for mathematics gifted education. Second,, in third enrichment course(Student's Centered Mathematical Modeling Activity), gifted students conduct the problem presentation, division of roles, select and collect the information, draw conclusions by discussion. In process of achievement, high level mathematical competency and intellectual capacity are needed so synthetic thinking ability, problem solving, creativity and self-directed learning ability are appeared to gifted students. Third, in third enrichment course(Student's Centered Mathematical Modeling Activity), problem solving, mathematical connections, information processing competency are appeared.