• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.43 no.7
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• pp.601-608
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• 2015

The static aeroelastic analysis and optimization of flexible wings are conducted for steady state conditions while both aerodynamic and structural parameters can be used as optimization variables. The system of multidisciplinary design optimization as a robust methodology to couple commercial codes for a static aeroelastic optimization purpose to yield a convenient adaptation to engineering applications is developed. Aspect ratio, taper ratio, sweepback angle are chosen as optimization variables and the skin thickness of the wing. The real-coded adaptive range multi-objective genetic algorithm code, which represents the global multi-objective optimization algorithm, was used to control the optimization process. The support vector regression(SVR) is applied for optimization, in order to reduce the time of computation. For this multi-objective design optimization problem, numerical results show that several useful Pareto optimal designs exist for the flexible wing.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.40 no.3
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• pp.251-257
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• 2012

The flight controller should meet the flying qualities, stability margins, and time response requirement according to the class of a target aircraft or UAV. Classical design process of PID controller is a very time consuming process and needed trial and erros. The best way is to apply the multi-disciplinary optimization algorithm to meet the numerous constraints of controller requirements. This paper presents how multi-objective parameter optimization (CONDUIT) can be used to determine many design parameters of lateral stability and augmentation system for roll and heading controller of the small UAV. To verify the effectiveness of applying the optimization method, designed controller using optimization are compared with the baseline controller that is designed only considering the time responses.

• Journal of the Korea Safety Management & Science
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• v.1 no.1
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• pp.69-77
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• 1999

One of the objectives of any task design is to provide a safe and helpful workplace for the employees. The safety and health module may include means for confronting the design with safety and health regulations and standards as well as tools for obstacles and collisions detection (such as error models and simulators), Virtual Reality is a leading edge technology which has only very recently become available on platforms and at prices accessible to the majority of simulation engineers. The design of an automated manufacturing system is a complicated, multidisciplinary task that requires involvement of several specialists. In this paper, a design procedure that facilitates the safety and ergonomic considerations of an automated manufacturing system are described. The procedure consists of the following major steps. Data collection and analysis of the data, creation of a three-dimensional simulation model of the work environment, simulation for safety analysis and risk assessment, development of safety solutions, selection of the preferred solutions, implementation of the selected solutions, reporting, and training. When improving the safety of an existing system the three-dimensional simulation model helps the designer to perceive the work from operators point of view objectively and safely without the exposure to hazards of the actual system.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.140-145
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• 2005

The dynamic performances of railway vehicles, such as ride comfort, stability and safety, have the opposite characteristics of response each other according to design changes of suspensions. For this reasons, it is necessary that multidisciplinary engineers join in design processes of the suspensions so as to satisfy the requirements of dynamic performance with design constraints. Sometimes iterative dynamic analyses are required so many times during the design processes. In this paper, the development of integrated process environments and the dynamic analyses of railway vehicles based on the environments are presented. Using agent and wrapping technologies, process managements about the work process and design parameters were set up under the distributed computing environments. Also, dynamic analyses on the sample railway vehicle were carried out and the efficiency and improvement in future work were discussed as results.

• International Journal of CAD/CAM
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• v.2 no.1
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• pp.1-12
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• 2002

Computer-Aided Reliable and Optimal Design (CAROD) system is an efficient tool defining the best compromise between cost and safety. Using the concurrent engineering concept, it can supply the designer with all numerical information in the design process. This system integrates several fields such as multidisciplinary optimization, reliability analysis, finite element analysis, geometrical modeling, sensitivity analysis and concurrent engineering. When integrating these disciplines, many difficulties are found such as model coupling and computational time. In this paper, we propose a new concurrent methodology satisfying the reliability requirement, allowing the coupling of different models and reducing the computational time. Two applications (rotating disk and hook structures) demonstrate that CAROD system can be a practical concurrent engineering application for designers.

• Journal of the Korean Solar Energy Society
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• v.32 no.5
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• pp.1-10
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• 2012

This paper proposes a modeling and controller design approach for a wind-diesel hybrid system including dump load. Wind turbine depends on nature such as wind speed. It causes power fluctuations of wind turbine. Excessive power fluctuation at stand-alone power grid is even worse than large-scale power grid. The proposed control scheme for power quality is fuzzy PI controller. This controller has advantages of PI and fuzzy controller. The proposed model is carried out by using Matlab/Simulink simulation program. In the simulation study, the proposed controller is compared with a conventional PI controller. Simulation results show that the proposed controller is more effective against disturbances caused by wind speed and load variation than the PI controller, and thus it contributes to a better quality wind-diesel hybrid power system.

• Journal of computational fluids engineering
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• v.11 no.3 s.34
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• pp.1-7
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• 2006

Euler and Navier-Stokes flow analyses for helicopter rotor in hover were performed as low and high fidelity analysis models respectively for the future multidisciplinary design optimization(MDO). These design-oriented analyses possess several attributes such as variable complexity, sensitivity-computation capability and modularity which analysis models involved in MDO are recommended to provide with. To realize PC-based analyses for both fidelity models, reduction of flow domain was made by appling farfield boundary condition based on 3-dimensional point sink with simple momentum theory and also periodic boundary condition in the azimuthal direction. Correlations of thrust, torque and their sensitivities between low and high complexity models were tried to evaluate the applicability of these analysis models in MDO process. It was found that the low-fidelity Euler analysis model predicted inaccurate sensitivity derivatives at relatively high angle of attack.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.273-276
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• 2004

Multidisciplinary Design Optimization (MDO) is an individual and parallel design framework applied in designing large and complex systems. for successful implementation of MDO framework it is essential to manage data in efficient and integrated manner. In this study, we present a case study to implement database to support designing super high temperature vacuum furnace with MDO technology. For that purpose we first extract required data based on the analysis of design process and then data flows between different programs are analyzed. Finally an E-R diagram is presented to design database schema.

• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.78-82
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• 2010

An integrated multi-disciplinary design system plays a critical role in the preliminary design of an aircraft. In this paper such system is developed for the multi-disciplinary computation and design; aerodynamics elasticity, and radio frequency stealth. Common data base of geometry and structured grids is generated and used for aerodynamic, structural and eletromagnetics analysis. The Navier-Stokes CFD, FEM, and CEM technique are used for aerodynamic, structural, and RF stealth computations respectively.

• 시스템엔지니어링워크숍
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• s.4
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• pp.95-100
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• 2004

A System engineering is a management technique that simultaneously interates all essential acquisition activities through the use of multidisciplinary teams to optimize the design, manufacturing, business, and supportability processes. This work describes two case studies of the defence acquistion prigram applied SE. It is presented a general understanding of SE and perspective of SE applications for defense acquisition process.