• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.3
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• pp.320-327
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• 2017

The main function of an infuser is to ensure constant dosage of a drug. Elastomer drug infusers have been used widely owing to their economic advantages. The mechanism of the device is primarily based on the pressure created from the elastic material that contains the drugs. However, as the drug is infused and the internal pressure is reduced, the drug is not linearly infused at all times. This study involves investigating factors to improve the design of the infuser. The first factor is the range of proper deformation, which does not affect a significant amount of stress variation during infusion. The second is concerned with the flow restrictor and the associated design variables are recommended by employing finite element analysis and the factorial experiment technique. The last factor is related to the spring device connected to balloon. The results showed that the drug reservoir can compensate for unexpected pressure gradient drops.

• Journal of Power System Engineering
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• v.21 no.5
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• pp.86-91
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• 2017

Friction Stir Welding (FSW) is useful technique to join aluminum alloy with energy efficient and environment friendly. In this paper, the design of experiment with three-way factorial design was adopted for optimum conditions of welding variables in the FSW of Al 6061 alloy. Tools of shoulder diameter of 9, 12, 15 mm and pin length of 1.5 mm were used. Also the material's dimension for welding were $2{\times}100{\times}150mm$, and the tensile specimens were worked by water-jet technique. Welding variables were shoulder diameter, rotating speed and travel speed of tool. From the results of this work, the welding factor influenced on yield strength most was travel speed and the optimum condition for FSW was predicted as the shoulder diameter of 15 mm, welding speed of 500 mm/min and rotating speed of 2,000 rpm. Also the presumption range of yield strength at optimal condition of reliability 99% was estimated to $207.19{\pm}9.91MPa$.

• Journal of the Korean Society of Propulsion Engineers
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• v.13 no.4
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• pp.30-35
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• 2009

Effective-pivot effects on the thrust vector control performance of the flexible seal nozzle to be used to control the flight direction of missile were investigated by computer simulation. $2^3$-Design of experiment technique was applied and ADMAS was used for the surrogate technique. As a result, radial pivot position had more influence upon the nozzle actuating performance than axial pivot position. Connecting method of actuator was also important factor in determining effective-pivot effects on the thrust vector control performance of the flexible seal nozzle.

• Journal of Power System Engineering
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• v.19 no.4
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• pp.11-16
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• 2015

Welding is very popular method for joining two or more metals. In this paper, the three-way factorial design was adopted for obtaining the optimum friction stir welding conditions of Al 5052 alloy. Tools of shoulder diameter of 9, 12, 15 mm and pin length of 1.5 mm were used. Also the material's dimension for welding was $100{\times}100{\times}2mm$, and the tensile specimens were worked by water-jet technique. Welding variables were shoulder diameter, rotating speed of tool and welding speed. As far as this work is concerned, optimum condition for friction stir joint of Al 5052 alloy was predicted as the shoulder diameter of 15 mm, welding speed of 500mm/min and rotating speed of 1000 rpm. In addition, the presumed range of tensile strength under the optimal conditions is estimated to be $208.3{\pm}5.7$ MPa with 99% reliability.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.4
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• pp.77-82
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• 2013

In this paper, the design of experiment with two-way factorial design was adopted and from that, optimum values of welding variables including the welding speed and rotation speed were found to improve the strength of AZ31 magnesium alloy sheets joined by the friction stir technique. Tool with shoulder diameter of 12 mm and pin diameter of 3.5 mm was used. Also the welding direction was aligned with the material rolling direction, and dimensions of the AZ31 magnesium alloy sheets were $100{\times}100{\times}2mm$. Conditions of rotation speed were 1000, 1100 and 1200 rpm and those of welding speed were 200, 300 and 400 mm/min. As far as this work is concerned, the optimal conditions for friction stir joint were predicted as the rotation speed of 1200 rpm and welding speed of 200 mm/min.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1305-1308
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• 2003

A new technique is presented to construct a predictive model of plasma etch process. This was accomplished by combining a backpropagation neural network (BPNN) and a genetic algorithm (GA). The predictive model constructed in this way is referred to as a GA-BPNN. The GA played a role of controlling training factors simultaneously. The training factors to be optimized are the hidden neuron, training tolerance, initial weight magnitude, and two gradients of bipolar sigmoid and linear functions. Each etch response was optimized separately. The proposed scheme was evaluated with a set of experimental plasma etch data. The etch process was characterized by a $2^3$ full factorial experiment. The etch responses modeled are aluminum (A1) etch rate, silica profile angle, A1 selectivity, and dc bias. Additional test data were prepared to evaluate model appropriateness. The GA-BPNN was compared to a conventional BPNN. Compared to the BPNN, the GA-BPNN demonstrated an improvement of more than 20% for all etch responses. The improvement was significant in the case of A1 etch rate.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.30 no.7 s.250
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• pp.700-706
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• 2006

This study presents a numerical procedure to optimize the shape of dimple surface to enhance turbulent heat transfer in a rectangular channel. The response surface based optimization method is used as an optimization technique with Reynolds-averaged Wavier-Stokes analysis of fluid flow and heat transfer with shear stress transport (SST) turbulence model. The dimple depth-to-dimple print diameter ratio, channel height-to-dimple print diameter ratio, and dimple print diameter-to-pitch ratio are chosen as design variables. The objective function is defined as a linear combination of heat transfer related term and friction loss related term with a weighting factor. full factorial method is used to determine the training points as a mean of design of experiment. The optimum shape shows remarkable performance in comparison with a reference shape.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.12
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• pp.159-167
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• 2003

In this paper, a two-dimensional multibody DADS model of a moving walk is developed to improve the ride quality of a moving walk system. The proposed DADS model is able to estimate the longitudinal acceleration of moving walk system, which is the more sensitive and important than other accelerations. To show the validity of the developed model, the longitudinal accelerations of pallet obtained from the computer simulations are compared to the experimental data in frequency domain. Then, the factorial design technique is applied to determine the main design factor and to improve the ride quality. The change of the spring compression in the lower part of the tension generating system improved the ride quality of the moving walk system.

• The KSFM Journal of Fluid Machinery
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• v.7 no.6 s.27
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• pp.55-61
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• 2004

A numerical procedure for optimizing the shape of three-dimensional sedimentation tank is presented to maximize its sedimentation efficiency. The response surface based optimization is used as an optimization technique with Reynolds-averaged Navier-Stokes analysis for multi-phase flow. Standard $k-{\epsilon}$ model is used as a turbulence closure. Three design variables such as, tank height to center feed wall diameter ratio, blockage ratio of center feed wall and angle of distributor are chosen as design variables. Sedimentation efficiency is defined as an objective function. Full-factorial method is used to determine the training points as a means of design of experiment. Sensitivity of each design variable on the objective function has been evaluated. And, optimal values of the design variables have been obtained.

• 유체기계공업학회:학술대회논문집
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• 2004.12a
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• pp.285-288
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• 2004

This study presents a numerical procedure to optimize the shape of dimple surface to enhance turbulent heat transfer in rectangular channel. The response surface based optimization method is used as an optimization technique with Reynolds-averaged Wavier-Stokes analysis of fluid flow and heat transfer with shear stress transport (SST) turbulence model. The dimple depth-to -dimple print diameter ratio, channel height- to- dimple print diameter ratio. and dimple print diameter-to-pitch ratio are chosen as design variables. The objective function is defined as a linear combination of heat transfer coefficient and friction drag coefficient with a weighting factor. Full factorial method is used to determine the training points as a mean of design of experiment.