• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.266-271
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• 2006

Characteristic of partial oxidation of methane using arc-jet plasma by AC power is investigated. Arc-jet reactor used in this work is slightly modified from typical arc jet reactor so that it can make and sustain stable state of plasma. Methane conversion, selectivity of chemicals such as hydrogen and hydrocarbon materials in the product are analyzed. Parametric approach on the performance of the reactor or detail on the partial oxidation process is carried with $O_2/C$ ratio as parameter. In addition to the results, SED and arc length is changed to understand the effect of current-voltage correlation on the reforming performance and relative role of thermal process.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.109-112
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• 1997

In this note, we investigate a noniterative design method of an observer-based robust H$\_$2/ controller in the presence of structured real parameter uncertainty by applying Riccati approach based on the guaranteed cost function. Motivated by the numerical difficulty of the problem, we try to develop a simple design method named as block-diagonal approach, which can be solved by the LMIs method. By assuming the block-diagonal structure of Riccati solution, the original problem can be derived into two sequentially decoupled optimization problems as LQG control problem. The proposed method seems to be numerically efficient in obtaining a feasible compensator.

• Journal of Institute of Control, Robotics and Systems
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• v.15 no.6
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• pp.612-618
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• 2009

This study is concerned about the optimal design of the arm 1 and arm 2 in the SCARA robot. The mass and inertia moment of the arm I and arm 2 in a SCARA robot is greatly affected on the performance such as a cycle time, and torques loaded on $1^{st}$ axis and $2^{nd}$ axis. To reduce the mass and inertia moment, this study carried out optimal design by FEM analysis using parametric variables, which is a width, a height of the rib and a thickness of arm in the arm. The rib is adapted instead of reducing the thickness in the arm. And the simulation by computer was conducted on two given paths in X direction and Y direction. After optimal design, the result showed that maximum torque of $1^{st}$ axis and $2^{nd}$ axis reduced to maximum 9.5% on a given path.

• International Journal of Aeronautical and Space Sciences
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• v.17 no.3
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• pp.378-390
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• 2016

A concept of the perch landing assisted by thruster (PLAT) for a fixed wind aircraft is proposed in this paper. The proposed concept is applicable to relatively large unmanned aerial vehicles (UAV), hence can overcome the limitation of existing perch landing technologies. A planar rigid body motion of an aircraft with aerodynamic and thruster forces and moments is modeled. An optimal control problem to minimize the fuel consumption by determining the histories of thruster and elevator deflection angle with specified terminal landing condition is formulated and solved. A parametric study for various initial conditions and thruster parameters is conducted to demonstrate the practicability of the proposed concept.

• 한국전산유체공학회:학술대회논문집
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• 2009.04a
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• pp.66-69
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• 2009

New design configurations were developed based on the closed ventilation type igloo nozzle in contrast to the conventional open distribution type. To validate the enhanced performance, the prediction of the exhaust flow patterns of the igloo diffuser was carried out by both experimental and computational simulations. CFD provided detailed parametric studies that significantly reduced the amount of experimentation necessary to alter the design of existing the F-15K igloo exhaust diffuser.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.179-184
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• 1993

In this paper, an optimal motion control scheme is proposed for robot manipulators. A simple explicit solution to the Hamilton-Jacobi equation is presented. The optimization of motion control is based on the mininization of the torque term affecting the kinetic energy and the augmented error which has the first-order stable dynamics for the position and velocity tracking error. In the presence of parametric uncertainty, an adaptive control scheme using the optimal principle is proposed. The global stability of the closed-loop system is guaranteed by the Lyapunov stability approach, The effectiveness and feasibility of the proposed control schemes are shown by simulation results.

• Proceedings of the KSME Conference
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• 2004.11a
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• pp.655-660
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• 2004

The pipes in the outdoor unit of an air conditioner are designed to reduce the vibration effect of the compressor. Three-dimensional structure of the pipe could provide various design choices and the resultant vibration characteristics of the outdoor units. A design program has been developed for an eligible parametric study of pipe design and automatic vibration analysis using commercial software, I-DEAS, and its macro. Optimal design of pipe configuration has been performed using the commercial software, iSIGHT. The optimized design shows 70 percents improvement in the vibration characteristics of the outdoor unit of an air conditioner.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.27 no.1
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• pp.1-7
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• 2003

The optimal design for the shape of MIL-S-46119 ring obturator under the high pressure using parameter stud:』 on the stress analysis considering effects of design variable is presented, and it is compared to experimental results. The trends of parametric study are in good agreement with the experimental results. The more thickness the higher stress. The more taper the higher stress. And maximum stress of circumferential surface is larger than maximum stress of forward surface. The design variable!; are such as thickness, taper, radius of shape of the obturator. In order to optimize the shape of obturation ring, the weight is maximized subject to maximum stress of the obturator within allowable stress. The design constraints are geometric elements of design variables.

• Proceedings of the KSME Conference
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• 2007.05a
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• pp.532-537
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• 2007

Nano imprint lithography(NIL) is a cost-efficient, high-throughput processing technique to transfer nano-scale patterns onto thin polymer films. Polymers used as the resist include UV cured resins as well as thermoplastics such as polymethyl-methacrylate(PMMA). In this study, an analytic investigation was performed for the NIL process of transferring nano scale patterns onto polymeric films. Process optimization calls for a thorough understanding of resist flow during the process. We carried out 2D and 3D numerical analyses of resist flow during NIL process. The simulation incorporated continuum-hypothesis and the effects of surface tension were taken into account. For a more effective prediction of free surface, fixed grid scheme with the volume of fluid (VOF) method were used. The simulation results were verified with experimental results qualitatively. And the parametric study was performed for various process conditions.

• Journal of Korean Society for Atmospheric Environment
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• v.18 no.2
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• pp.85-94
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• 2002

In this study, a 3-dimensional numerical model, has been developed applied for the investigation of combustion characteristics, and used to optimize operating conditions in MSW incinerator, in Gwangju. The model developed in this study has been verified by exacting both the predicted and the measured temperature in combustion chamber which has been operated to provide a reference condition. By predictive results, the Sangmoo incinerator has a good characteristics of combustion and low emission however after burning zone produced incomplete products, also probably because the supply of primary air was not enough. Parametric screening studies have been conducted to study optimal operating conditions. For the optimal combustion characteristics, operating conditions should be adjusted with the waste properties.