• International Journal of Advanced Culture Technology
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• v.1 no.2
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• pp.13-17
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• 2013

Today, most of the companies have numerous issues to take advantage of the data within the organization. Modeling techniques could be described using profile and historical log data as a tool of data mining techniques. It is covered increasingly with data entry, research, processing, modeling and reporting components of the icon in the form of easy-to-use in many datamining tools. Visual data mining process can create a data stream. In this paper, customer behavior is predicted in pages or products, using the history profile analysis and the navigation items are necessary to predict unknown features.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.10a
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• pp.366-371
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• 1995

it is extremely difficult to perform the dynamic experiments with full-scale specimens. For this reason, small-scale structural models offer an attractive means to peform dynamic loading experiments. The purpose of this reserch is to estabilish the reliance for modeling techniques of small-scale specimens subjected to dynamic cyclic loading. This research focused on the similitude requirements for reinforced concrete frame structures subjected to dynamic cyclic loading. Length scale ratio of specimens were 1:2:4, and six specimens were tested at the frequencies of 0.0025Hz~2.0Hz. It was confirmed that modeling techniques based on the similitude requirements were useful method to evaluate the behavior of full-size R/C structures subjected to earthquake type loading.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.137-140
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• 2005

Exfoliated nanocomposites of polypropylene/layered silicate were prepared by a melt compounding process using maleic anhydride modified polypropylene (PP-g-MAH) and organoclay. It was found that polypropylene/layered silicate nanocomposites exhibited remarkable reinforcement compared with the pure polypropylene or conventional composite filled with agglomerated organoclay. The polypropylene /layered silicate nanocomposites showed stronger and earlier shear thinning behaviors and outstanding strain hardening behavior than pure polypropylene or other conventional composites in shear and uniaxial elongational flows, respectively. We simulated rheological modeling for the pure polymer matrix and polypropylene/layered silicate nanocomposite in shear and elongational flows using K-BKZ integral constitutive equation. The two types of K-BKZequations have been examined to describe experimental results of shear and uniaxial elongational viscosities of pure polypropylene and polypropylene/layered silicate nanocomposite.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1135-1138
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• 2003

ERFs(Electrorheological Fluids) arc a complex system consisting of polarizable particles and insulation liquid. When an external electric field is applied to ERFs, its apparent viscosity increases dramatically. This phenomenon is called the ER effect. Generally, the behavior of ERFs has been modeled on those of Bingham fluids. But the behavior of ERFs differs from those of Bingham fluids in many respects. In the paper, ER effect concerning flow mode of ERFs is analyzed experimentally. According to several flow conditions, the change of ER effect is presented and visualized. A new modeling methodology of ER effect to reduce the modeling error is presented.

• Structural Engineering and Mechanics
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• v.31 no.3
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• pp.297-314
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• 2009

When the temperature of a structure varies, there is a tendency to produce changes in the shape of the structure. The resulting actions may be of considerable importance in the analysis of the structures having non-prismatic members. Therefore, this study aimed to investigate the modeling, analysis and behavior of the non-prismatic members subjected to temperature changes with the aid of finite element modeling. The fixed-end moments and fixed-end forces of such members due to temperature changes were computed through a comprehensive parametric study. It was demonstrated that the conventional methods using frame elements can lead to significant errors, and the deviations can reach to unacceptable levels for these types of structures. The design formulas and the dimensionless design coefficients were proposed based on a comprehensive parametric study using two-dimensional plane-stress finite element models. The fixed-end actions of the non-prismatic members having parabolic and straight haunches due to temperature changes can be determined using the proposed approach without necessitating a detailed finite element model solution. Additionally, the robust results of the finite element analyses allowed examining the sources and magnitudes of the errors in the conventional analysis.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.269-278
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• 2003

In this study, the method of the finite element modeling for free vibration control of beam-type smart structures with bonded plate-type piezoelectric sensors and actuators is proposed. Constitutive equations for the direct piezoelectric effect and converse piezoelectric effect of piezoelectric materials are considered. By using the variational principle, the equations of motion for the smart beam finite element are derived, The proposed 2-node beam finite element is an isoparametric element based on Timoshenko beam theory. Therefore, by analyzing beam-type smart structures with smart beam finite elements, it is possible to simulate the control of the structural behavior by applying voltages to piezoelectric actuators and monitoring of the structural behavior by sensing voltages of piezoelectric sensors. By using the smart beam finite element and constant-gain feed back control scheme, the formulation of the free vibration control for the beam structures with bonded plate-type piezoelectric sensors and actuators is proposed.

• Computers and Concrete
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• v.12 no.4
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• pp.565-583
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• 2013

Existing numerical models for strain-hardening cement-based composites (SHCC) are short of providing sufficiently accurate solutions to the failure patterns of coupling beams of different designs. The objective of this study is to develop an effective model that is capable of simulating the nonlinear behavior of SHCC coupling beams subjected to cyclic loading. The beam model proposed in this study is a macro-scale plane stress model. The effects of cracks on the macro-scale behavior of SHCC coupling beams are smeared in an anisotropic model. In particular, the influence of the defined crack orientations on the simulation accuracy is explored. Extensive experimental data from coupling beams with different failure patterns are employed to evaluate the validity of the proposed SHCC coupling beam models. The results show that the use of the suggested shear stiffness retention factor for damaged SHCC coupling beams is able to effectively enhance the simulation accuracy, especially for shear-critical SHCC coupling beams. In addition, the definition of crack orientation for damaged coupling beams is found to be a critical factor influencing the simulation accuracy.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.203-203
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• 2000

The P&S(Power Plant Simulation System) is a powerful simulation software system for the dynamic behavior of power plants. The P&S module libraries provide plant models with higher flexibility of dynamic simulations for process and control designs. The P&S software was effectively available for PCS based on Linux and modem workstations based on Unix. The P&S was applied for simulating the dynamic behaviors of the SOVR(Supercritical Once-Through Variable Pressure Reheater) according to the operations such as stan-up, shutdown, load following, load change and trip in order to obtain an optimal operation procedure for Unit 5/6 of Taeahn fossil power plant consisted of SOVRs and steam turbines.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.643-647
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• 1996

The dynamic behavior of hydrostatic table is represented as the theoretical model, 1-dof, 2-dof rigid body spring-damper system, and finite element model. By the experimental and theoretical methods, the validity of these models and some other dynamic behaviors, such as the effects of unbalanced load and three dimensional motion, are investigated. To make easier to consider the dynamic behavior of hydrostatic table in design process, the stiffness and damping coefficients are calculated using the simple approximation method delived from the mass flow continuity condition, and compared with experimental results.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.490-492
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• 2005

최근 사용자 행태 분석 개념이 매우 중요한 이슈가 되고 있으며, HCI(Human-Computer Interface)의 관점에서 사용자의 행태와 시스템 모델링은 적절한 모델링 언어나 도구가 부족하여 사용자의 행태를 전부 표현하지 못한다. 소프트웨어공학에서는 시스템을 설계하기 위해 UML(Unified Modeling Language)을 사용하여 시스템을 모델링하고 있다. 물론 UML에 액터 개념은 있으나 시스템 중심의 모델에 초점을 두고 있어, 사용자의 행태 표현에 제약이 존재한다. 이에 본 논문에서는 사용자 행태를 모델링하기위해 OBA(Object Behavior Analysis)방법론을 기반으로 사용자 행태에 초점을 맞춰 시스템을 모델링 하고, 결과로써 HCI관점을 위해 부족한 UML의 문제와 확장성을 언급하고자 한다.