A Mixed-Variable Experimental Design Method

Mixed-variable problems are inevitable in engineering. However, few researches pay attention to discrete variables. This paper proposed a mixed-variable experimental design method (ODCD): first, the design variables were divided into discrete variables and continuous variables;then, the DVD method was employed for handling discrete variables, the LHD method was applied for continuous variables, and finally, a Columnwise-Pairwise Algorithm was used for the overall optimization of the design matrix. Experimental results demonstrated that the ODCD method outperforms in terms of the sample space coverage performance.

A Spider Monkey Optimization Algorithm Combining Opposition-Based Learning and Orthogonal Experimental Design

As a new bionic algorithm,Spider Monkey Optimization(SMO)has been widely used in various complex optimization problems in recent years.However,the new space exploration power of SMO is limited and the diversity of the population in SMO is not abundant.Thus,this paper focuses on how to reconstruct SMO to improve its performance,and a novel spider monkey optimization algorithm with opposition-based learning and orthogonal experimental design(SMO^(3))is developed.A position updatingmethod based on the historical optimal domain and particle swarmfor Local Leader Phase(LLP)andGlobal Leader Phase(GLP)is presented to improve the diversity of the population of SMO.Moreover,an opposition-based learning strategy based on self-extremum is proposed to avoid suffering from premature convergence and getting stuck at locally optimal values.Also,a local worst individual elimination method based on orthogonal experimental design is used for helping the SMO algorithm eliminate the poor individuals in time.Furthermore,an extended SMO^(3)named CSMO^(3)is investigated to deal with constrained optimization problems.The proposed algorithm is applied to both unconstrained and constrained functions which include the CEC2006 benchmark set and three engineering problems.Experimental results show that the performance of the proposed algorithm is better than three well-known SMO algorithms and other evolutionary algorithms in unconstrained and constrained problems.

Factorial Experimental Design to Study the Effects of Layers and Fiber Content on Concrete Flexural Behavior

Experimentation has come a long in helping researchers achieve breakthroughs in their different scientific areas and engineering happens to be one of those areas with the most impact from experimental advancement. The need for valid experimental results free from biases and confounding conclusions has prompted the development of new experimental techniques that takes consideration of all applicable factor and combinations in providing answers on a research topic, and the Factorial Experimental design credited to Sir Ronald Fisher is one technique yielding highly valid results. This paper uses the factorial design of experiments to research the flexural impact of polyvinyl acetate fiber and layered concrete in construction. The experiment considered two levels of fiber contents and two levels of layers, and prepared samples with all combinations of the variable factors. The samples were tested after 7 days from casting for flexural strength and an advance statistical analysis was performed on the flexural responses of the samples using R-program. The results from the analyses revealed the significance of the variables to the flexural strength of the samples, as well as their interactions. The experiment concluded that based on the number of layers and fiber content used for the experiment, casting concrete in layers does have a significant negative effect on the flexural strength of concrete, and the failure pattern of concrete members under flexural load in evidently influenced by the material composition of the concrete, and that it can be evidently influenced by casting the concrete in layers.

The Study of Optimizing Reservoir Model Using Experimental Design in Stochastic Models

In response to the main problems in commonly used model selection methods,a method was proposed to apply the concept of experimental design to the optimization of uncertain reservoir models.Firstly,based on the actual situation of the oil field,the uncertain variables were determined that affect the geological reserves of the model and their possible range of variation,and experimental design was used to determine the modeling plan.Then,multiple geological models were established and reserves were calculated,and multiple regression was performed between uncertain variables and the corresponding geological reserves of the model.Finally,Monte Carlo simulation technology was applied to determine the parameters of the P10,P50,and P90 models for probabilistic reserves,and P10,P50,and P90 models were established.This method is not only more objective and time-saving in the application process,but also can determine the main geological variables that affect geological reserves,providing a new idea for evaluating the uncertainty of geological reserves.

Experimental Design for Computer System Platform Course

The computer system platform course is a comprehensive platform course formed by modifying and optimizing the content of the relevant basic courses of computer major to meet the requirement for basic computer knowledge in digital media technology major.The scope and extent of the course content make its experimental design more challenging.By considering the scope of contents,the difficulty of experiments,and the rationality of intrinsic logic,the experiments covering from operating system to computer network are designed.The relevance and continuity of the experiments are ensured,so as to achieve the goals of promoting students’understanding of key concepts,improving their hands-on ability,cultivating their interest,and guiding their self-learning within the limited class time.

An iterated local coordinate-exchange algorithm for constructing experimental designs for multi-dimensional constrained spaces

Iterated local search(ILS)is used to construct the optimal experimental designs for multi-dimensional constrained spaces,in which the inner loop is based on the stochastic coordinate-exchange(SCE)algorithm.Every time a local optimal solution is found by the SCE algorithm,the perturbation operator is applied to it,and then a new solution is explored in the areas where the exchange of coordinates may produce improvement,so as to retain the features and attributes of the current optimal solution and avoid the defects of random restart.We implement the iterated local coordinate-exchange algorithm for experimental designs in the multi-dimensional constrained spaces.In addition,sensitivity analysis was conducted to analyze the impacts of the parameters on the performance of the proposed algorithm.Also we compared the performance of the proposed algorithm to the SCE algorithm using the random restart strategy.The analysis shows that the proposed algorithm is better than the SCE algorithm in terms of efficiency and quality,especially in the experimental designs for high-dimensional constrained space.

New HPLC Method with Experimental Design and Fluorescence Detection for Analytical Study of Antihypertensive Mixture,Amlodipine and Valsartan

New HPLC method was developed for determination of amlodipine and valsartan in their binary mixture as a part of routine control of combined formulations. The method was validated to meet official requirements including selectivity, stability, linearity, precision and accuracy. Chromatography was carried out using a LiChrospher RP-18 column, a mixture containing acetonitrile, phosphate buffer of pH 3.5 and methanol (45:45:10, v/v/v) and new fluorescence detection at 255 nm for excitation and 448 nm for emission. The effect of methanol content, pH of the buffer, flow rate, detection wavelengths and column temperature was estimated in robustness study, according to a plan defined by the Plackett-Burman design. For identification of significant effects, both graphical and statistical methods were used. Ro-bustness for dissolution test was checked estimating the effects of paddle speed, temperature and pH of dissolution medium. The method was proved to complying with all official guidelines. Therefore, it is suitable for determination of amlodipine and valsartan in their binary mixtures for different analytical and pharmaceutical purposes.

Development and in-vitro evaluation of an optimized carvedilol transdermal therapeutic system using experimental design approach

The effect of formulation variables on in-vitro release and permeation properties of carvedilol from transdermal patch was studied by varying one factor at a time as preliminary study.Based on these results,design of experiments technique was applied followed by regression analysis and response surface methodology to optimize formulation variables.Central Composite IV model design was used with four formulation variables:drug loading,matrix thickness,adhesive layer thickness,and propylene glycol concentration.Nineteen formulations were prepared according to the design;and the effect of formulation variables was studied on in-vitro release and permeation profiles of these formulations.In all cases,the permeation profiles paralleled in-vitro release profiles.The drug released at 7 h and 24 h was used as release response parameters while permeation flux obtained was employed as permeation response parameter.All four formulation variables were found to be significant for release properties and three of these exhibited significant effect on permeation profile of carvedilol across artificial membrane.Constrained optimization,using 47.9%of cumulative carvedilol released at 7 h and 99.8%at 24 h as well as 25.7 mg/cm2/h of permeation flux,was applied to obtain desired release and permeation profiles.Experimentally,carvedilol was observed to release from the optimized formulation with 51.4%drug release at 7 h and 98.5%at 24 h with an observed flux value of 27.4 mg/cm2/h across artificial membrane,which showed an excellent agreement with the predicted values.The results of this investigation show that the quadratic mathematical model developed could be used to further predict formulations with desirable release and permeation properties.

The Statistical Experimental Design for Chemical Reactors Modeling

The Statistical Experimental Design techniques are the most powerful tools for the chemical reactors experimental modeling. Empirical models can be formulated for representing the chemical behavior of reactors with the minimal effort in the necessary number of experimental runs, hence, minimizing the consumption of chemicals and the consumption of time due to the reduction in the number of experimental runs and increasing the certainty of the results. Four types of nonthermal plasma reactors were assayed seeking for the highest efficiency in obtaining hydrogen and ethylene. Three different geometries for AC high voltage driven reactors, and only a single geometry for a DC high voltage pulse driven reactor were studied. According to the fundamental principles of chemical kinetics and considering an analogy among the reaction rate and the applied power to the plasma reactor, the four reactors are modeled following the classical chemical reactors design to understand if the behavior of the nonthermal plasma reactors can be regarded as the chemical reactors following the flow patterns of PFR (Plug Flow Reactor) or CSTR (Continuous Stirred Tank Reactor). Dehydrogenation is a common elimination reaction that takes place in nonthermal plasmas. Owing to this characteristic, a paraffinic heavy oil with an average molecular weight corresponding to C15 was used to study the production of light olefins and hydrogen.

Optimization of Expanded Polystyrene Lightweight Aggregate in Pre-Cast Concrete Blocks by a Completely Random Experimental Design (CRED) with Mixture and Process Variables

The aim of this study was to determine the optimum design mix to produce pre-cast concrete blocks by a completely random experimental design (CRED) with mixture and process variables. The polymerized concrete was studied its composition: Cement, and water defined as the mixture compounds. To choose the best model, all the possible models were assessed through the ANOVA, which tested each possible model. The linear-linear model was preferred, since that do not present evidence of lack of fit, and it is capable of relating how to react the process variables, when are changed the variable mixture condition levels. The optimum experimental condition, obtained for the polymerized concrete, was: The size of the polystyrene beads was 4.8 mm sized polystyrene beads, 5.0% polystyrene that replaced the aggregate, 18.3% cement, 73.4% aggregate and 8.3% water. In this condition, the blocks made with polymerized concrete show a compressive strength above 15 Mpa, allowing its utilization in paving.

Research on the Application of Intelligence Teaching Mode of Superstar Platform in the Teaching of Experimental Design and Data Processing

Experimental Design and Data Processing is an important core professional basic course for food science majors.This course is theoretical and practical,and there are many formulas,abstract contents and difficult to understand,and there are some problems in the teaching process,such as students1 poor interest in learning,insufficient mastery of what they have learned,and inability to combine theory with practice organically.Through analyzing the existing problems,this paper puts forward some reform measures for the teaching mode of experimental design and data processing by using the intelligent teaching of Superstar platform.

Experimental Design in Solvent Extraction: A Study for Divalent Metals Separation in D2EHPA/Isoparaffin System

The solvent extraction process combined with tools of experimental design assists in developing procedures for separation and purification of elements or mineral compounds with high purity. In this work the technique was used to replace the traditional methods for the collection of basic information required for the development of a circuit of solvent extraction. According to the literature, several factors may influence the extraction of divalent metals by D2EHPA in sulfate media, among which the concentration of metals in solution. The objective was to study the variables affecting the separation process Mn/Ni/Co/Cu, such as the aqueous/organic (A/O), contact time, concentrations of the divalent metals in sulfuric medium, pH and solvent concentration. An investigation into the variables that control the process was done using a “cube + star” experimental design, with central point. The results demonstrate it is possible to obtain of a satisfactory mathematical model that describes the process.

An Assessment Scale for Evaluating the Experimental Design Ability of Elementary Science Teachers Based on Primary Trait Analysis

In this study,an assessment scale for evaluating the experimental design ability of elementary science teachers was constructed based on primary trait analysis.This assessment scale contains three first-level indexes and eleven second-level indexes.The corresponding weights of indexes were determined by the objective weighting method.The scores of all the descriptions of the indexes were also assigned.After a trial test,this assessment scale was verified to be reliable and valid for evaluating the experimental design ability of elementary science teachers.

Designing an Experimental Device for Swinging Excitation Spray Cooling

In this paper,we introduce the design principle of the oscillating excited spray cooling experimental device.We then designed an oscillating excited spray cooling experimental device.By using the device,the swaying motion can be realized through the control system,and the motion of the droplet under different vibration frequencies can be observed.By measuring the liquid flow rate and pressure,the changes in liquid flow rate,pressure,and temperature with time under different vibration frequencies were studied.The trajectory of the droplet and the temperature distribution of the droplet under different vibration frequencies could be observed.The device has a simple structure,is easy to control,and can achieve continuous observation of the spray cooling process.

Optimization of Center of Gravity Position and Anti-Wave Plate Angle of Amphibious Unmanned Vehicle Based on Orthogonal Experimental Method

When the amphibious vehicle navigates in water,the angle of the anti-wave plate and the position of the center of gravity greatly influence the navigation characteristics.In the relevant research on reducing the navigation resistance of amphibious vehicles by adjusting the angle of the anti-wave plate,there is a lack of scientific selection of parameters and reasonable research of simulation results by using mathematical methods,and the influence of the center of gravity position on navigation characteristics is not considered at the same time.To study the influence of the combinations of the angle of the anti-wave plate and the position of the center of gravity on the resistance reduction characteristics,a numerical calculation model of the amphibious unmanned vehicle was established by using the theory of computational fluid dynamics,and the experimental data verified the correctness of the numerical model.Based on this numerical model,the navigation characteristics of the amphibious unmanned vehicle were studied when the center of gravity was located at different positions,and the orthogonal experimental design method was used to optimize the parameters of the angle of the anti-wave plate and the position of the center of gravity.The results show that through the parameter optimization analysis based on the orthogonal experimental method,the combination of the optimal angle of the anti-wave plate and the position of the center of gravity is obtained.And the numerical simulation result of resistance is consistent with the predicted optimal solution.Compared with the maximum navigational resistance,the parameter optimization reduces the navigational resistance of the amphibious unmanned vehicle by 24%.

Simultaneous Determination of Bismuth,Lead,and Iron in Water Samples by Optimization of USAEME and ICP–OES via Experimental Design

Ultrasound-assisted emulsification–microextraction followed by inductively coupled plasma–optical emission spectrometry was utilized for simultaneous pre-concentration and trace detection of lead,bismuth,and iron in water samples.Disodium N,N -bis(salicylidene)ethylenediamine and trichloroethylene were used as chelating agent and extraction solvent,respectively.The parameters of interest were volume of extraction solvent,temperature,and concentrations of salt and chelating agent.A fractional factorial design was developed to identify these parameters and how they vary with one another.The results demonstrated that the concentrations of salt and chelating agent affected extraction efficiency.Subsequently,a central-composite design was used to acquire optimum levels of effective parameters.The optimal conditions were 160.7 mg L^(−1) and 1.77%(w/v)for concentration of chelating agent and salt,respectively.The linear dynamic ranges were determined to be 1–1000μg L^(−1) for Pb and Bi,and 10–1000μg L^(−1) for Fe.The correlation coefficient(R2)was 0.990–0.995.The limits of detection were 0.54–0.78μg L^(−1).The relative standard deviation(concentration=200μg L^(−1),n=8)was in the range of 2.0–4.3%.This method was successfully applied for the trace detection of Pb,Bi,and Fe in freshwater samples of waterfall and spring and satisfactory relative recoveries(96.2–99.6%)were obtained.

Process Characterization of the Transesterification of Rapeseed Oil to Biodiesel Using Design of Experiments and Infrared Spectroscopy

For optimization of production processes and product quality,often knowledge of the factors influencing the process outcome is compulsory.Thus,process analytical technology(PAT)that allows deeper insight into the process and results in a mathematical description of the process behavior as a simple function based on the most important process factors can help to achieve higher production efficiency and quality.The present study aims at characterizing a well-known industrial process,the transesterification reaction of rapeseed oil with methanol to produce fatty acid methyl esters(FAME)for usage as biodiesel in a continuous micro reactor set-up.To this end,a design of experiment approach is applied,where the effects of two process factors,the molar ratio and the total flow rate of the reactants,are investigated.The optimized process target response is the FAME mass fraction in the purified nonpolar phase of the product as a measure of reaction yield.The quantification is performed using attenuated total reflection infrared spectroscopy in combination with partial least squares regression.The data retrieved during the conduction of the DoE experimental plan were used for statistical analysis.A non-linear model indicating a synergistic interaction between the studied factors describes the reactor behavior with a high coefficient of determination(R^(2))of 0.9608.Thus,we applied a PAT approach to generate further insight into this established industrial process.

Design and Robust Performance Evaluation of a Fractional Order PID Controller Applied to a DC Motor

This paper proposes a methodology for the quantitative robustness evaluation of PID controllers employed in a DC motor. The robustness analysis is performed employing a 2~3 factorial experimental design for a fractional order proportional integral and derivative controller(FOPID), integer order proportional integral and derivative controller(IOPID)and the Skogestad internal model control controller(SIMC). The factors assumed in experiment are the presence of random noise,external disturbances in the system input and variable load. As output variables, the experimental design employs the system step response and the controller action. Practical implementation of FOPID and IOPID controllers uses the MATLAB stateflow toolbox and a NI data acquisition system. Results of the robustness analysis show that the FOPID controller has a better performance and robust stability against the experiment factors.

Hydrogen-based direct reduction of industrial iron ore pellets:Statistically designed experiments and computational simulation

As part of efforts to reduce anthropogenic CO_(2) emissions by the steelmaking industry,this study investigated the direct reduction of industrially produced hematite pellets with H_(2) using the Doehlert experimental design to evaluate the effect of pellet diameter(10.5-16.5 mm),porosity(0.36-0.44),and temperature(600-1200℃).A strong interactive effect between temperature and pellet size was observed,indicating that these variables cannot be considered independently.The increase in temperature and decrease in pellet size considerably favor the reduction rate,while porosity did not show a relevant effect.The change in pellet size during the reduction was negligible,except at elevated temperatures due to crack formation.A considerable decrease in mechanical strength at high temperatures suggests a maximum process operating temperature of 900℃.Good predictive capacity was achieved using the modified grain model to simulate the three consecutive non-catalytic gas-solid reactions,considering different pellet sizes and porosities,changes during the reaction from 800 to 900℃.However,for other temperatures,different mechanisms of structural modifications must be considered in the modeling.These results represent significant contributions to the development of ore pellets for CO_(2)-free steelmaking technology.

A study of storage conditions for pre-mashed fried Semen Zizyphi Spinosae using a multi-factor orthogonal design

Background:To facilitate the preparation of traditional Chinese medicines they are pre-mashed,i.e.,mashed in advance.However,storage conditions for pre-mashed traditional Chinese medicines are based on subjective judgments of pharmacists,and the best storage conditions have not generally been determined.Semen Zizyphi Spinosae is a commonly used traditional Chinese medicine,and it is usually used after it is fried.The medicine needs to be mashed in a timely manner to ensure its effectiveness.The Chinese Pharmacopoeia provides a limit for its aflatoxin content.Methods:The orthogonal experimental design method optimizes the best plan for pre-mashed fried Semen Zizyphi Spinosae.Experimental conditions were defined using the L^(9)(3^(4))orthogonal design table.Four factors and three levels were used to study storage conditions.The four factors and three levels are as follows:storage temperature(10°C,20°C,and 30°C),storage humidity(45%,60%,and 75%),storage times(10,20 and 30 days),and particle sizes for the powder(coarsest,coarse and medium powders).The contents of jujuboside A,spinosin,aflatoxin B1,total aflatoxins(aflatoxins B1,B2,G1,and G2),moisture,total ash,acid value,and saponification values were measured.Results:The results demonstrated that the highest jujuboside A and spinosin contents were obtained using a storage temperature of 20°C,a storage humidity of 75%,a storage time of 10 days,and with a coarse powder particle size.Aflatoxin B1 and total aflatoxins(aflatoxins B1,B2,G1 and G2)were not detected under these conditions.Conclusion:There is no requirement for traditional Chinese medicines to be pre-mashed.This study evaluated various storage conditions for pre-mashed fried Semen Zizyphi Spinosae,and considered the influence of four factors on the contents of jujuboside A,spinolin and aflatoxin for quality control to provide a reference for other pre-mashed traditional Chinese medicines.