• 산업기술연구
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• 제22권A호
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• pp.83-87
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• 2002

Many industrial products such as paints, ink and adhesives are composed of the ingredients of a mixture. In mixture experiments, the characteristics of quality(response) depends only on the proportions of the ingredients and does not depend on the total amount of the mixture. This article discusses the constrained mixture experimental design, the data analysis, and the optimum formulation of ingredients based on the two quality characteristics - taste and flavor. It IS shown that efficient designs can be constructed from D-optimal criterion. Special cubic models were selected as the final mixture response surfaces for both reponses. The desirability function was used for the optimization of the two responses.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2007년도 추계 학술대회논문집
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• pp.92-99
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• 2007

In this paper, optimization of the vaned centrifugal compressor was carried out at a given mass flow rate condition. Firstly, impeller optimization was conducted using response surface method (RSM) which is one of optimization methods. After the optimization of the impeller was completed, diffuser optimization was performed with the optimized impeller. In these processes, Navier-Stokes solver was used to calculate the flow inside the centrifugal compressor. And the optimization is performed with Box-Behnken design method which is efficient for fitting second-order response surfaces to reduce the number of calculations required. As a result, compared with the reference model, the efficiency and the pressure ratio of the optimized impeller and diffuser are found to be increased. The performance at off-design conditions is presented.

• 대한기계학회논문집A
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• 제31권9호
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• pp.924-933
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• 2007

An impeller is a important part of turbo-machinery. It has a set of twisted surfaces because it consists of many blades. Five-axis machining is required to produce a impeller because of interference between tool and workpiece. It can obtain good surface integrity and high productivity. This paper proposes finish cutting method for machining impeller with 5-axis machining center and optimization of cutting condition by response surface method. Firstly, cutting methods are selected by consideration of operation characteristics. Secondly, response factors are determined as cutting time and cutting error for prediction of productivity. Experiments are projected by central composite design with axis point. Thirdly, regression linear models are estimated as single surface in the leading edge and as dual surface in the hub surface cutting. Finally, cutting conditions are optimized.

• Smart Structures and Systems
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• 제8권5호
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• pp.449-470
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• 2011

During the last thirty years many structural control concepts have been proposed for the reduction of the structural response caused by earthquake excitations. Their research and implementation in practice have shown that seismic control of structures has a lot of potential but also many limitations. In this paper the importance of two practical issues, time delay and saturation effect, on the performance of controlled structures, is discussed. Their influence, both separately and in interaction, on the response of structures controlled by a modified pole placement algorithm is investigated. Characteristic buildings controlled by this algorithm and subjected to dynamic loads, such as harmonic signals and actual seismic events, are analyzed for a range of levels of time delay and saturation capacity of the control devices. The response reduction surfaces for the combined influence of time delay and force saturation of the controlled buildings are obtained. Conclusions regarding the choice of the control system and the desired properties of the control devices are drawn.

• 한국유체기계학회 논문집
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• 제19권2호
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• pp.16-20
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• 2016

Design optimization of a transonic compressor rotor(NASA rotor 37) was carried out using response surface method(RSM) which is one of the optimization methods. A numerical simulation was conducted using ANSYS CFX by solving three-dimensional Reynolds-averaged Navier Stokes(RANS) equations. Response surfaces that were based on the results of the design of experiment(DOE) techniques were used to find an optimal shape of blade which has the maximum aerodynamic performance. Two objective functions, viz., the adiabatic efficiency and the loss coefficient were selected with three design configurations to optimize the blade shape. As a result, the efficiency of the optimized blade is found to be increased.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1999년도 추계학술대회 논문집
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• pp.549-552
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• 1999

We have developed an novel vertical-alignment (VA) - $\pi$ cell mode that provides a wide viewing angle and fast response times for negative dielectric anisotropy nematic liquid crystal (NLC) on a homeotropic polyimide (PI) surfaces. We had the good voltage-transmittance curves and low driving voltages were achieved with the novel VA - $\pi$ cell mode without negative compensation film. Iso-viewing angle characteristics using the novel VA - $\pi$ cell mode without negative compensation film of NLC was also successfully observed. As well a fast response time of 31.7ms for the novel VA - $\pi$ cell mode was measured. Consequently, It is seen that by using the novel VA - $\pi$ cell mode the iso-viewing angle, fast response time, and low driving voltage characteristics can be achieved.

• 오토저널
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• 제13권1호
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• pp.35-45
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• 1991

A linear quarter model of a vehicle suspension system is built and simulated. Especially the so-called sensitivity analysis is conducted in order to show its applicability to design problems, and sensitivity function is determined in the frequency domain. The change of frequency response function is predicted, which depends on the design parameter variation and the property is verified by computer simulation. Typical performance measures, namely, sprung mass acceleration, suspension deflection, and tire deflection are examined. The vehicle model is analyzed for ist performance sensitivity as a function of the system's feedback gains. The variable feedback gains are selected as the spring and damping coefficients. Frequency response, RMS response, and performance index of the performance evaluation variables are considered and three-dimensional and contour plots of response surfaces are formed to examine output sensitivity to suspension feedback. Performance trade-offs over the entire frequency spectrum are identified from the FRF, and that between ride quality and handling characteristics are examined from the RMS responses.

• The Journal of Asian Finance, Economics and Business
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• 제2권2호
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• pp.13-18
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• 2015

In this paper the DRC model is presented for solving multi objective problem. The proposed model is a combination of data envelopment analysis, Cuckoo algorithm and the response surface method. Due to reasons like costs, time and irreversible damages, it is not possible to analyze each and every one of the proposed models in practice, so the simulation is used. Since the number of experiments for simulation process is high then the optimization has gone to practice and directs the simulation process. The response surface method is used as one of the approaches of simulation optimization. Furthermore, data envelopment analysis is used to consider several response surfaces as efficiency response surface. Then this efficiency response surface is solved by Cuckoo algorithms. The main advantage of DRC model is to make one efficiency response surface function instate of multi surface function for every output and also using the advantages of Cuckoo algorithms. In order to demonstrate the effectiveness of the proposed approach, the branches of Refah bank in Mashhad is analyzed and the results are presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1759-1761
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• 1999

The generation of pretilt in nematic liquid crystal(NLC)and electro-optical(EO) characteristics of photo-aligned twisted nematic (TN)-LCD with oblique p-polarized ultraviolet (UV) light irradiation on the two kinds of the soluble polyimide (PI) surfaces containing trifluoromethyl moieties were investigated. The generated pretilt angle of NLC is about $2.5^{\circ}$ with p-polarized UV light irradiation of $20^{\circ}$ on PI-3 surface at 20 min.; However pretilt angle of about $0.5^{\circ}$ are observed on PI-1 and PI-2 surfaces. The generated pretilt angle of NLC on PI-3 surface may be attributed to the trifluoromethyl moieties attached to the lateral benzene rings. The voltage-transmittance and response time characteristics of photo-aligned TN-LCD with p-polarized UV light irradiation of $20^{\circ}$ on PI-1 surfaceat at 20 min were almost same in comparison with the rubbing-aligned TN-LCD. However, the high threshold voltage and slow response are observed on PI-3 surface. Also, the decay time $\tau_d$ of photo-aligned TN-LCD is attributed to the anchoring energy of NLC.

• Transactions on Electrical and Electronic Materials
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• 제6권4호
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• pp.135-139
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• 2005

In this paper, negative SU-8 photoresist processed at low temperature is characterized in terms of delamination. Based on a $3^3$ factorial designed experiment, 27 samples are fabricated, and the degree of delamination is measured for each. In addition, nine samples are fabricated for the purpose of verification. Employing the. neural network modeling technique, a process model is established, and response surfaces are generated to investigate degree of delamination associated with three process parameters: post exposure bake (PEB) temperature, PEB time, and exposure energy. From the response surfaces generated, two significant parameters associated with delamination are identified, and their effects on delamination are analyzed. Higher PEB temperature at a fixed PEB time results in a greater degree of delamination. In addition, a higher dose of exposure energy lowers the temperature at which the delamination begins and also results in a larger degree of delamination. These results identify acceptable ranges of the three process variables to avoid delamination of SU-8 film, which in turn might lead to potential defects in MEMS device fabrication.