• Nonlinear Functional Analysis and Applications
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• v.26 no.2
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• pp.225-236
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• 2021

In this paper, we determine position vector of a line of curvature of a regular surface which is relatively normal-slant helix, with respect to Darboux frame. Then, a vector differential equation is established by means Darboux formulas, in the case of the geodesic torsion is vanishes. In terms of solution, we determine the parametric representation of a line of curvature which is relatively normal-slant helix, with respect to standard frame in Euclidean 3-space. Thereafter, we apply this result to find the position vector of a line of curvature which is isophote curve.

• Communications of the Korean Mathematical Society
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• v.33 no.4
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• pp.1309-1320
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• 2018

In this paper, we show that proper biharmonic spacelike curve ${\gamma}$ in Lorentzian Heisenberg space (${\mathbb{H}}_3$, g) is pseudo-helix with ${\kappa}^2-{\tau}^2=-1+4{\eta}(B)^2$. Moreover, ${\gamma}$ has the spacelike normal vector field and is a slant curve. Finally, we find the parametric equations of them.

• Computational Structural Engineering
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• v.31 no.2
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• pp.4-8
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• 2018

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.36 no.3
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• pp.229-237
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• 2008

In this research, a MDO(multi-disciplinary design optimization) framework, which integrates aerodynamic and structural analysis to design an aircraft wing, is constructed. Whole optimization process is automated by a parametric-modeling approach. A CFD mesh is generated automatically from parametric modeling of CATIA and Gridgen followed by automatic flow analysis using Fluent. Finite element mesh is generated automatically by parametric method of MSC.Patran PCL. Aerodynamic load is transferred to Finite element model by the volume spline method. RSM(Response Surface Method) is applied for optimization, which helps to achieve global optimum. As the design problem to test the current MDO framework, a wing weight minimization with constraints of lift-drag ratio and deflection of the wing is selected. Aspect ratio, taper ratio and sweepback angle are defined as design variables. The optimization result demonstrates the successful construction of the MDO framework.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.42 no.3
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• pp.243-253
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• 2014

This paper deals with the Quantitative Feedback Thoery(QFT) guaranteeing robustness in spite of the plant parametric uncertainty. In the frequency domain, the QFT guarantees the robustness of the design specification on the uncertainty of plant parameters and disturbance. In order to use the QFT, a selected plant is a Quad Rotor Vehicle(QRV) which has excellent maneuverability and possibility of vertical take-off and landing like the helicopter. And attitude control is examined the possibility satisfied the requirement specification under the setting parametric uncertainty of motors driving 4-blades. Additionally, in an attitude control, the pre-filter considering parameter range and operating range of a QRV was used. For these purpose, in this paper, by using QFTCT, that is the QFT Control Toolbox designing the controller in MATLAB by the QFT, each design phases are introduced.

• Journal of the Korean Mathematical Society
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• v.46 no.6
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• pp.1319-1338
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• 2009

In this paper, using proximal-point mappings technique of Raccretive mappings and the property of the fixed point set of set-valued contractive mappings, we study the behavior and sensitivity analysis of the solution set of the system of parametric generalized quasi-variational inclusions involving R-accretive mappings in real uniformly smooth Banach space. Further under suitable conditions, we discuss the Lipschitz continuity of the solution set with respect to parameters. The technique and results presented in this paper can be viewed as extension of the techniques and corresponding results given in [3, 23, 24, 32, 33, 34].

• Korean Journal of Computational Design and Engineering
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• v.9 no.3
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• pp.226-237
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• 2004

If the topology changes in the re-generation step of the history-based and feature-based CAD systems, it is difficult to identify an entity in the old model and find the same entity in the new model. This problem is known as 'persistent naming problem'. To exchange parametric CAD models, the persistent naming problem and the naming mapping problem must be solved among different CAD system, which use different naming scheme. For CAD model exchange the persistent naming has its own characteristics compare to that for CAD system development. This paper analyses previous researches and proposes a solution to the persistent naming problem for CAD model exchanges and to the naming mapping problem among different naming schemes.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.3
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• pp.75-78
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• 2008

Tire molds are manufactured by aluminum casting, direct five-axis machining, and electric discharging machining. Master models made of chemical wood are necessary if aluminum casting is used. They are designed with a three-dimensional computer-aided design system and milled by a five-axis machine. In this paper, a method for generating and machining a tire surface model is proposed and demonstrated. The groove surfaces, which are the main feature of the tire model, are created using a parametric design concept. An automatically programmed tool-like descriptive language is presented to implement the parametric design. Various groove geometries can be created by changing variables. For convenience, groove surfaces and raw cutter location (CL) data are generated in two-dimensional drawing space. The CL data are mapped to the tread surface to obtain five-axis CL data to machine the master model. The proposed method was tested by actual milling using the five-axis control machine. The results demonstrate that the method is useful for manufacturing a tire mold.

• Communications of the Korean Mathematical Society
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• v.36 no.1
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• pp.103-119
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• 2021

In this article, we study a system of generalized set-valued parametric ordered variational inclusion problems with operator ⊕ in ordered Banach spaces. We introduce the concept of the resolvent operator associated with (α, λ)-ANODSM set-valued mapping and establish the existence theorem of solution for the system of generalized set-valued parametric ordered variational inclusion problems in ordered Banach spaces. In order to prove the existence of solution, we suggest an iterative algorithm and discuss the convergence analysis under some suitable mild conditions.

• Nonlinear Functional Analysis and Applications
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• v.26 no.5
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• pp.917-933
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• 2021

In this paper, we investigate the behavior and sensitivity analysis of a solution set for a parametric generalized multi-valued nonlinear quasi-variational inclusion problem in a real Hilbert space. For this study, we utilize the technique of resolvent operator and the property of a fixed-point set of a multi-valued contractive mapping. We also examine Lipschitz continuity of the solution set with respect to the parameter under some appropriate conditions.