• Journal of Electrochemical Science and Technology
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• v.15 no.3
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• pp.388-404
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• 2024

In the present work, the operating parameters were optimized using Box Behnken Design (BBD) in response surface methodology (RSM) to maximize the hydrogen production rate (R₁) and hydrogen production rate per unit watt consumed (R₂) of a proton exchange membrane electrolysis cell (PEMEC), a third response (R₃) which was the sum of the scaled values of R₁ and R₂ were selected to be maximized so that both hydrogen production rate and hydrogen production rate per unit watt consumed could be maximized. The major parameters which were influencing the experiment for enhancing the output responses were oxygen electrode/anode electrocatalyst loading (A), current supplied (B) and water inlet temperature (C). The commercial proton exchange membrane Nafion^® was used as the electrolyte. The acetylene black carbon (C_AB) supported IrO₂ was used as the electrocatalyst for preparing oxygen electrode/anode whereas commercial Pt (40 wt%)/C_HSA was used as the H₂ electrode/cathode electrocatalyst. The quadratic model was developed to predict the output/ responses and their proximity to the experimental output values. The developed model was found to be significant as the P values for both the responses were < 0.0001 and F values were greater than 1. The optimum condition for both the responses were O₂ electrode/anode electrocatalyst loading of 1.78 mg/cm², supplied current of 0.33 A and water inlet temperature of 54℃. The predicted values for hydrogen production rate (R₁) and hydrogen production rate per unit watt consumed (R₂) were 2.921 mL/min and 2.562 mL/(min·W), respectively obtained from the quadratic model. The error % between the predicted response values and experimental values were 1.47% and 3.08% for R₁ and R₂, respectively. This model predicted the optimum conditions reasonably in good agreement with the experimental conditions for the enhancement of the output responses of the developed PEM based electrolyser.

• Food Science and Biotechnology
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• v.17 no.2
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• pp.379-383
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• 2008

Extraction characteristics of garlic and functional properties of corresponding extract were monitored by response surface methodology (RSM). Maximum extraction yield of 26.41% was obtained at microwave power of 146.29 W, ethanol concentration of 63.31 %, and extraction time of 5.88 min. At microwave power, ethanol concentration, and extraction time of 114.84 W, 58.83%, and 1.42 min, respectively, maximum electron-donating ability (EDA) was 72.86%. Maximum nitrite-scavenging ability was 94.62% at microwave power, ethanol concentration, and extraction time of 81.83 W, 2.65%, and 3.83 min, respectively. Superoxide dismutase (SOD) showed maximum pseudo-activity of 49.12% at microwave power of 34.23 W, ethanol concentration of 33.11 %, and extraction time of 4.40 min. Based on superimposition of 4-dimensional RSM with respect to extraction yield, electron-donating ability, nitrite-scavenging ability, and pseudo-activity of SOD, optimum ranges of extraction conditions were microwave power of 0-100 W, ethanol concentration of 40-70%, and extraction time of 2-8 min.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.355-359
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• 2001

This paper presents an implementation of digital control system of speed sensorless for Reluctance Synchronous Motor (RSM) drives with DTC. The control system consists of stator flux observer, rotor position/speed/torque estimator, two hysteresis band controllers, an optimal switching look-up table, IGBT voltage source inverter, and TMS320C31 DSP controller by using fully integrated control software. The stator flux observer is based on the combined voltage and current model with stator flux feedback adaptive control that inputs are current and voltage sensing of motor terminal with estimated rotor angle for wide speed range. The rotor position is estimated by observed stator flux-linkage space vector. The estimated rotor speed is determined by differentiation of the rotor position used only in the current model part of the flux observer for a low speed operating area. It does not require the knowledge of any motor parameters, nor particular care for motor starting, In order to prove the suggested control algorithm, we have a simulation and testing at actual experimental system. The developed sensorless control system is shown a good speed control response characteristic results and high performance features in 50/1000 rpm with 1.0Kw RSM having 2.57 ratio of d/q reluctance.

• Proceedings of the KIPE Conference
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• 2001.12a
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• pp.23-26
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• 2001

This paper presents a digital motion control system for Reluctance Synchronous Motor (RSM) drives with direct torque control (DTC). The system consists of stator flux observer, torque estimator: two hysteresis band controllers, an optimal switching look-up table, IGBT voltage source inverter(VSI), and TMS320C31 DSP controller by using fully integrated control software. The stator flux observer is based on the combined voltage and current model with stator flux feedback adaptive control of which inputs are current, voltage and actual rotor angle for wide speed range. In order to prove the suggested motion control algorithm, There are some simulation and testing at actual experimental system. The developed digitally high-performance motion control system are shown a good motion control response characteristic results and high performance features using 1.0Kw RSM.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.15 no.5
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• pp.65-71
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• 2006

This paper presents the robust design of gripper part for a high-speed LCD(Liquid Crystal Display) transfer system. In this paper, the $1^{st}$ DOE(Design of Experiment) is conducted to find out main-effect factors for the design of gripper part. Thirty-six analysis are performed using $ANSYS^{(R)}$ and their results are statistically analyzed using $MINITAB^{(R)}$, which shows that the factors, i.e., First-width, Second-width, Rec-width, and thickness of gripper part, are more important than other factors. The main effect plots shows that the maximum deflection and mass of gripper part are minimized by increasing First-width, Second-width, Rec-width and thickness. The $2^{nd}$ DOE is conducted to obtain RSM(Response Surface Method) equation. The CCD(Central Composite Design) technique with four factors is used. Optimum design is conducted using the RSM equation. Genetic algorithm is used for optimal design. Six sigma robust design is conducted to find out a guideline for control range of design parameter. To obtain six sigma level quality, the standard deviations of design parameters are shown to be controlled within 5% of average design value.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.51 no.3
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• pp.150-157
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• 2002

This paper presents preliminarily an implementation of digital high-performance motion control system of Reluctance Synchronous Motor (RSM) drives with direct torque control (DTC). The system consist of stator flux observer, torque estimator, two hysteresis band controllers, an optimal switching look-up table, IGBT voltage source inverter, and TMS320F240 DSP controller made by Texas Instruments. The stator fluff observer is based on the combined voltage and current model with stator flux feedback adaptive control, and the input of the observer are the stator voltage and current of motor terminal for wide speed range. The rotor position and speed sensor used 6000 pulse/rev encoder. In order to prove rightness of the suggested control algorithm, we have some simulation and actual experimental system at $\pm$20 and $\pm$2000 rpm. The developed digitally high-performance motion control system+ are shown a good response characteristic of control results and high performance features using 1.0kW RSM which has 2.57 Ld/Lq salient ratio.

• Journal of Korean Society on Water Environment
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• v.25 no.6
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• pp.943-950
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• 2009

Cadmium (Cd) adsorption onto the activated carbon containing hydroxyapatite (HAP) was investigated in batch experiments and response surface methodology (RSM) using the Box-Behnken methods were applied to the experimental results. Cd adsorption with different HAP mass ratio of from 10% to 30%. With more HAP, Cd was more adsorbed. These results suggest that the higher HAP mass causes an increase of the ion exchange potential of the HAP sorbent. Equilibrium experimental results from Cd adsorption was fitted to Langmuir and Freundlich isotherm models. Cd adsorption on HAP sorbent were found to follow the Freundlich isotherm model well in the initial adsorbate concentration range. Also, Cd adsorption was a function of the HAP mass ratio ($x_1$), initial Cd concentration ($x_2$), and initial pH ($x_3$) from the application of the RSM. Statistical results showed the order of significance of the independent variables to be initial Cd concentration > HAP mass ratio > initial pH.

• Proceedings of the KIEE Conference
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• 2001.07e
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• pp.47-52
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• 2001

This paper presents a high-performance control system for Reluctance Synchronous Motor (RSM) drives with direct torque control (DTC). The system consist of stator flux observer, rotor position/speed estimator, torque estimator, two hysteresis band controllers, an optimal switching look-up table, IGBT voltage source inverter, and F240/C31DSP controller by using fully integrated control software. The stator flux observer is based on the combined voltage and current model with stator flux feedback adaptive control that inputs are current and voltage sensing of motor terminal with estimated rotor angle for wide speed range. The rotor position is estimated by the observed stator flux-linkage space vector. The estimated rotor speed can be determinated by differentiation of the rotor position used only in the current model part of the flux observer for a low speed operating area. To prove the suggested control algorithm, we have a simulation and testing at actual experimental system. The developed digitally high-performance position sensorless control system are shown a good motion control response characteristic results and high performance features using 1.0Kw RSM.

• Journal of the Korean Chemical Society
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• v.57 no.6
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• pp.769-777
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• 2013

The effect of operating conditions (temperature and the partial pressures of H2 and CO) on the reaction rate of Fischer-Tropsch synthesis (FTS) were investigated by carrying out experiments according to a Box-Behnken design (BBD), and were mathematically modeled by using response surface methodology (RSM). The catalyst used was a nano-structured cobalt/manganese oxide catalyst, which was prepared by thermal decomposition. The rate of synthesis was measured in a fixed-bed micro reactor with $H_2/CO$ molar feed ratio of 0.32-3.11 and reactor pressure in the range of 3-9.33 bar at space velocity of $3600h^{-1}$ and a temperature range of 463.15-503.15 K, under differential conditions (CO conversion below 2%). The results indicated that in the present experimental setup, the temperature and the partial pressure of CO were the most significant variables affecting reaction rate. Based on statistical analysis the quadratic model of reaction rate of FTS was highly significant as p-value 0.0002.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.161-164
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• 2001

This paper presents a digital speed sensorless control system for Reluctance Synchronous Motor (RSM) drives with direct torque control (DTC). The system consist of stator flux observer, rotor speed estimator, torque estimator two hysteresis band controllers, an optimal switching look-up table. IGBT voltage source inverter, and TMS320C31DSP controller by using fully integrated control software. The stator flux observer is based on the combined voltage and current model with stator flux feedback adaptive control that inputs are current and voltage sensing of motor terminal with estimated rotor angle for wide speed range. The rotor speed is estimated by the observed stator flux-linkage space vector. The estimated rotor speed can be determinated by differentiation of the rotor position used only in the current model part of the flux observer for a low speed operating area. In order to prove the suggested speed sensorless control algorithm. There are some simulation and testing at actual experimental system. The developed digitally high- performance speed sensorless control system are shown a good speed control response characteristic results and high Performance features using 1.0Kw RSM.