Papers by Keyword: Response Surface Method (RSM)

Abstract: Box-Behnken experiment design was used to optimize the enzymolysis technology of casein, and the antibacterial activity of casein peptides was evaluated. The optimum enzymolysis conditions was trypsin and neutral 1:1, pH7.4, temperature 44°C, substrate concentration 32g/L, E/S 2.5%, when the casein was hydrolyzed for 90 minutes, the antibacterial ability of peptide hydrolyzed from casein would reached 15%, and its antibacterial activity achieved a peak of inhibition ratio 82%. The results suggested that excessive hydrolysis products of casein would lose its antibacterial activity, but the modest hydrolysis product of casein has potential application value in antibacterial agent use.

Abstract: Response surface methodology (RSM) was applied to optimize the magnetic coagulation conditions for micro-polluted river water treatment. Based on single-factor experiment, Box-Behnken central composition experiment design was applied. The poly aluminum Chloride (PAC), magnetic particle, polyacrylamide (PAM), mixing stirring and flocculating stirring revolving speed were chosen as causal factors. RSM was employed to study the effects of these factors on the turbidity removal efficiency. Base on the target value (>95%), the results show that the optimum conditions were PAC 29.31mgL-1, magnetic particle 61.90mgL-1, PAM 0.48mgL-1, mixing stirring revolving speed 288rpm, flocculating stirring revolving speed 6 rpm. The average turbidity removal efficiency in three validation experiments was 95.36%, with the predicted value was 95.19%. The relative error between the measured data and the predicted value was 0.17%. It confirms that RSM was a useful tool to optimize the magnetic coagulation operating conditions for micro-polluted river water treatment.

Abstract: As for the reliability of ship-bridge collision, function relation between the structure response variable and basic variable is very complex and the traditional theory has been difficult to work it out, so we need the help of finite element numerical method to obtain the solution. APDL language and two methods are used to solve the reliability of ship-bridge collision, compared to seven MCS method conditions and ODRSM-MCS probability of failure of bridge pier. The pier failure probability of 10000 MCS method sampling and ODRSM-MCS sample is very close. ODRSM-MCS method and the MCS method to the case of the same accuracy, while MCS reliability is used in the calculation, the time used is 280min and the ODRSM-MCS mix of computational time is 5min. So the ODRSM-MCS method is much more efficient and effective.

Abstract: CFD (computational fluid dynamics) is a good method for simulation of the oil-gas separator. When the volume concentration is less than 10%, the oil particle tracks can be simulated by DPM （Discrete Phase Model）. The results show that the separation efficiency is obviously affected by the diameter of separator air-outlet, the diameter of separator oil-outlet, and the angle of separator cone. But the quantified analysis on separation efficiency is difficultly brought forward by CFD. RSM (response surface methods) can help to identify factors influencing the responses by experiments. Finally, the optimum responses and design parameters will be obtained altogether.

Abstract: Computer aided procedures to design and optimize forming processes have become crucial research topics as the industrial interest in cost and time reduction has been increasing. A standalone numerical simulation approach could make the design too time consuming while meta-modeling techniques enables faster approximation of the investigated phenomena, reducing the simulation time. Many researchers are, nowadays, facing such research challenge by using various approaches. Response surface method (RSM) is probably the most known one, since its effectiveness was demonstrated in the past years. The effectiveness of RSM depends both on the definition of the Design of Experiments (DoE) and the accuracy of the function approximation. The number of numerical simulations can be strongly reduced if a proper optimization approach is implemented: one of the main issues about optimization techniques is related to the design necessity of performing either global or local approximation. This paper aims to test the efficacy of some meta-modeling techniques in the optimization of a T-shaped hydroforming process. In this paper three optimization approaches based on different meta-modeling techniques are implemented. In particular, classical Polynomial Regression approach (PR), Moving Least Squares approximation (MLS) and Kriging method are applied. The results showed that, thanks to the peculiarities of MLS and Kriging methods, it is possible to strongly reduce the computational effort in sheet metal forming optimization, particularly in comparison with a classical PR approach. Differences were highlighted and quantified.

Abstract: Response surface method was used to optimize the process parameters of bio-packaging materials, which is produced by twin-screw extruder, in order to get the best performance, increase production levels. In this article, we use the Design Expert software, Box-Behnken Design module, under the conduction that the mass fraction of starch, plant fiber, polyethylene were respectively 70%,10%,30%, and keep a plasticizer to 5%, We analysis and optimize the screw extrusion temperature, speed and filler content, The results showed that the optimum technology parameters for screw speed 101.81 r•min-1, extrusion temperature 118.24°Cand filler content is 5.0.

Abstract: The seismic reliability analysis of complex structure is carried out based on the response surface method and finite element method. Firstly, the appropriate design points are selected based on the mean values and standard deviations of the basic random variables. Secondly, the finite element method is employed to obtain the values of the limit state function of the complex structure. Thirdly, with selected design points and the obtained values of the limit state function of the complex structure, a polynomial function is constructed to approximate the original implicit limit state function. Then, with the established explicit polynomial limit state function and available methods of structural reliability analysis, the seismic reliability of the complex structure is estimated. Numerical analyses show that the established method is simple to use for the evaluation of the reliability analysis of complex structure.

Abstract: The surface roughness model in the turning of 34CrMo4 steel was developed in terms of cutting speed, feed rate and depth of cut and tool nose radius using response surface methodology. Machining tests were carried out using several tools with several tool radius under different cutting conditions. The roughness equations of cutting tools when machining the steels were achieved by using the experimental data. The results are presented in terms of mean values and confidence levels.The established equation and graphs show that the feed rate and cutting speed were found to be main influencing factor on the surface roughness. It increased with increasing the feed rate and depth of cut, but decreased with increasing the cutting speed, respectively. The variance analysis for the second-order model shows that the interaction terms and the square terms were statistically insignificant. However, it could be seen that the first-order affect of feed rate was significant while cutting speed and depth of cut was insignificant.The predicted surface roughness model of the samples was found to lie close to that of the experimentally observed ones with 95% confident intervals.

Abstract: This paper reports on the development of predicted mathematical model for cutting force (F_c) during side milling of medium density fiberboard (MDF) using uncoated carbide insert. Box-Behnken design (BBD) of experiment, coupled with response surface method (RSM) were employed to establish the cutting force model. Evaluation on the effects and interactions of the machining variables on the cutting force were carried out. The machining variables involved include spindle speed, feed rate, routing width and were denoted by A, B and C respectively. Statistical analysis conducted on the experimental results indicated that the mathematical model for cutting force was adequate within the limits of factors being investigated. After eliminating the insignificant factors or model terms in the reduced model, it was found that factors A, B, C, B² (second order of B), C² (second order of C), were the most significant factors affecting the cutting force. BC (interaction of B and C) and AC (interaction of A and C) are the subsequent significant factors. Three-dimensional plots displaying the interactions between these significant factors were presented. The reduced model was then verified experimentally and statistically using ANOVA. It was evident that Box-Behnken design proved to be an efficient tool in identifying and constructing maps of interactions between the significant factors. Experimental results showed that lower cutting force can be obtained by employing higher cutting speed, low feed rate and lower routing width when side milling MDF using uncoated carbide insert.

Abstract: Most of the studies in Response Surface Methodology commonly involve one response or quality characteristics, whereas in most industrial applications considering all responses simultaneously is required. Multiple Response Surface (MRS) Optimization Problems often deal with responses that are conflicting. In dealing with incommensurate responses, incorporating a decision maker’s preference information into the problem has lots of advantages although a few researches in MRS literature have taken this into attention. The purpose of this paper is to take a detailed look at the most prominent approaches that has been suggested so far in MRS, and also to review and discuss the classifications with a special focus on the decision maker’s preference information. In today’s competitive market satisfying the customer is of high importance. The DM can be a customer and reaching a compromise with an interactive method would help the firm to succeed in having loyal customers. A case study is applied to show that interactive method with existing MRS approach leads to better results.