• 한국항공우주학회지
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• 제36권4호
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• pp.328-336
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• 2008

극초음속으로 비행하는 추진기관이 직면하는 고속 유동 등 제반 현상을 모사하기 위한 지상시험 설비로 충격파 풍동을 설계, 구축한 후 성능 시험을 수행하였다. 개발된 준 일차원 작동 해석을 이용하여 설계점을 파악한 후, 가압식 극고속 시험 구축을 위한 개념 설계를 완료하였다. 이어 단위 해석 코드를 이용하여 구체적인 성능 설계 및 각 구성품에 대한 설계를 완료, 구축한 후, 다양한 운용조건에서 성능시험을 수행하였다. 본 논문에서는 각 구성품 설계 및 구축방법, 구축 후 수행된 다양한 성능 시험 결과를 자세히 제시하였다.

• 한국생산제조학회지
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• 제22권5호
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• pp.859-864
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• 2013

Creation of a stress relief groove is a fairly simple yet high-performance method. During the application of this method, it is important to consider the location and size of the groove in order to achieve better performance. Consequently, this research proposes an approach for optimizing the application of the stress relief groove method to a press-fitted assembly. In a boss design, the position and diameter of the groove are configured as design variables and the design of experiments is applied. Based on this information, a 3D model is built and analyzed using the finite element analysis software ABAQUS. Meta-models are created using back-propagation neural networks. Then, deterministic optimization results obtained from a genetic algorithm are compared with the results of the finite element analysis. The temperature sensitivity of the optimized model is analyzed, and finally, reliability-based design optimization is conducted for enhancing the design quality.

• 복합신소재구조학회 논문집
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• 제6권2호
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• pp.1-7
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• 2015

As energy consumption of building and the reduction of carbon dioxide emissions have been emphasized, phase change materials(PCM) have been introduced as building materials due to its high heat storage performance. Using shape-stabilizing technique, octadecane/xGnP shape-stabilized PCM(SSPCM) can prevent leakage and improve heat storage performance. The objectives of this study are to propose mix design method of concrete mixed with SSPCM and to evaluate mechanical behaviors of the concrete mixed with SSPCM manufactured according to the proposed mix design. Based on the previously reported material test result, the existing mix design of plain concrete(Concrete standard specification, 2009) is modified to consider reduction of strength in concrete due to the addition of SSPCM. To verify the proposed mix design, specimens are fabricated according to the proposed mix design and axial strength tests and three-point loading tests are performed. Test results show that compressive strengths of the tested specimens reach the designed strength even when two different mix ratios of SSPCM are used. From three-point loading tests, flexural stresses decrease as mix ratio of SSPCM increases.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2004년도 춘계학술대회
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• pp.61-65
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• 2004

As technique that can contribute in quality improvement in design process to overcome shortcoming of traditional quality control, call design or development department quality control activity that is achieved to reduce gun damage shuddering at circle minimizing change or side effect of product performance as off-line quality control. This paper discuss optimal process design of investment projects expansion and replacement investment on each line or individual in the production. Generally optimal plant design has add to a few method by Subsidiary means with use a especial method. And then in this paper, a Robust design is presented, which may be effective to the processes appraisal or improvement. We propose that should make a optimal plant design model for reducing field failure rate to assign by real data on different factors in plant system. Using this model, robust design of taguchi method used in this comprehensive method for reducing field failure rate in plant system.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 V
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• pp.2589-2592
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• 2003

In this paper, a robust mixed H$_2$/H$\_$$\infty$/ output feedback control method is applied to the design of loop filter for PLL carrier phase tracking. The proposed method successfully copes with large S-curve slope uncertainty and a significant decision delay in the closed-loop that may exist In modern receivers due to a convolutional decoder or an equalizer. The objective is to design an output feedback controller which minimizes the H$_2$performance while satisfying the H$\_$$\infty$/ performance to guarantee the gain margin and phase margin for linear time invariant(LTI) polytopic uncertain systems. LMIs based approach is given to solve this problem. We can verify the H$\_$$\infty$/ performance satisfaction and minimize the phase detector error through the simulation result.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1998년도 추계종합학술대회 논문집
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• pp.409-412
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• 1998

In this paper, we present an $H^2$ controller design of RTP(rapid thermal processing) systems satisfying robust stability and performance using weighted mixed sensitivity minimization. In industrial fields, RTP system is widely used for improving the oxidation and the annealing in semiconductor manufacturing process. The main control factors are temperature control of wafer and uniformity has been solved by PID control method. Because the reference inputs of RTP are ramp, we improve performance of RTP system by the design of $H^2controller$ using the weighted mixed sensitivity function. Also we compare $H^2controller$ with PID controller in terms of performance. An example is proposed to show the validity of proposed method.

• 소음진동
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• 제11권2호
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• pp.234-240
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• 2001

Recently, the regulations from the government and the concerns of people be raised to the interest in exhaust and intake noise of passenger car as much as other vehicles. In these demands, performance prediction software was developed in this paper. In this study, Robust design was used for improving the noise reduction capacity of intake system with the performance prediction software. On the basis of the existing design, length and radius of each component that was thought to be effective to the performance of intake system was selected. At first, factors are arranged by using Ll8 table of orthogonal array and then optimum value can be obtained by modified Ll6 table of orthogonal array.

• 제어로봇시스템학회논문지
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• 제7권4호
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• pp.351-361
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• 2001

In this paper, a generalized framework called as robust internal-loop compensator(RIC) is presented, and by using this, a structural design method of sliding of sliding mode controller is proposed. First, a general sliding mode controller is derived and a stabilizing control input is designed based on Lyapunov redesign for the system in the presence of uncertainty and disturbance. And adopting the internal model following control, RIC is proposed. Next, using the structural characteristics of the proposed RIC, disturbance attenuation characteristics are analyzed and the performance of the closed-loop system is predicted. Through this analysis, it is shown that if the control gain of RIC is increased by N times, the magnitude of error is reduced to its 1/N. the proposed method is verified through experiments using a high-precision positioning system and the performance is evaluated.

• 한국생산제조학회지
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• 제24권6호
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• pp.696-702
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• 2015

This paper suggests a new method for making a navigation path by using Bezier curve in order to improve the navigation performance used to avoid obstacles during a robot soccer game. We analyzed the advantages and disadvantages of both vector-field and limit-cycle navigation methods, which are the mostly widely used navigation methods for avoiding obstacles. To improve the disadvantages of these methods, we propose a new design technique for generating a more proper path using Bezier curve and describe its advantages. Using computer simulations and experiments, we compare the performance of vector-field navigation with that of Bezier curve navigation. The results prove that the navigation performance using Bezier curve is relatively superior to the other method.

• 한국수소및신에너지학회논문집
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• 제33권5호
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• pp.583-590
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• 2022

In this paper, the performance characteristics of the 2 vane pump for wastewater treatment were investigated using response surface method(RSM) with commercial computation fluid dynamics(CFD) software. Design variables of wastewater treatment pump were defined with the meridional plane of the 2 vane pump impeller. The objective functions were defined as the total head and the efficiency at the design flow rate. The hydraulic performance of optimum model was verified by numerical analysis and the reliability of the model was retained by comparison of numerical analysis and comparative analysis with the reference model.