期刊文献+
共找到12,925篇文章
< 1 2 250 >
每页显示 20 50 100
Research on Landscape Design of Waterfront Public Space in Mountainous Cities Based on User Experience-Taking the Waterfront Landscape Design of Art Peninsula in Chongqing as an Example
1
作者 Haiyan Tang Miaoqing Zhang 《Journal of World Architecture》 2024年第5期47-53,共7页
Mountainous cities are dominated by mountainous,hilly,and steep terrain,which brings certain complexity and particularity to the planning and construction of waterfront spaces in these cities compared to plain cities.... Mountainous cities are dominated by mountainous,hilly,and steep terrain,which brings certain complexity and particularity to the planning and construction of waterfront spaces in these cities compared to plain cities.Waterfront spaces,often serving as the core areas of city development,possess favorable location advantages and special attributes of water-land intersection,giving them more possibilities for functional transformation[1].However,the ultimate goal of design is to provide users with a vibrant waterfront area.The design of waterfront spaces should focus more on people’s behavioral needs,allowing users to feel a good interaction between the place and their behavioral needs during space usage[2].Therefore,the design incorporates human environmental behavior,increases interactive experiences,and enriches spatial interest. 展开更多
关键词 User experience Interaction Waterfront landscape design
下载PDF
Interface Design and Functional Optimization of Chinese Learning Apps Based on User Experience
2
作者 Qihui Hong Jialing Hu Nianxiu Fang 《教育技术与创新》 2024年第2期59-78,共20页
This research paper investigates the interface design and functional optimization of Chinese learning apps through the lens of user experience.With the increasing popularity of Chinese language learning apps in the er... This research paper investigates the interface design and functional optimization of Chinese learning apps through the lens of user experience.With the increasing popularity of Chinese language learning apps in the era of rapid mobile internet development,users'demands for enhanced interface design and interaction experience have grown significantly.The study aims to explore the influence of user feedback on the design and functionality of Chinese learning apps,proposing optimization strategies to improve user experience and learning outcomes.By conducting a comprehensive literature review,utilizing methods such as surveys and user interviews for data collection,and analyzing user feedback,this research identifies existing issues in the interface design and interaction experience of Chinese learning apps.The results present user opinions,feedback analysis,identified problems,improvement directions,and specific optimization strategies.The study discusses the potential impact of these optimization strategies on enhancing user experience and learning outcomes,compares findings with previous research,addresses limitations,and suggests future research directions.In conclusion,this research contributes to enriching the design theory of Chinese learning apps,offering practical optimization recommendations for developers,and supporting the continuous advancement of Chinese language learning apps. 展开更多
关键词 Chinese Learning Apps User experience Interface design Functional Optimization
下载PDF
Process Characterization of the Transesterification of Rapeseed Oil to Biodiesel Using Design of Experiments and Infrared Spectroscopy
3
作者 Tobias Drieschner Andreas Kandelbauer +1 位作者 Bernd Hitzmann Karsten Rebner 《Journal of Renewable Materials》 SCIE EI 2023年第4期1643-1660,共18页
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 proc... 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. 展开更多
关键词 Process analytical technology TRANSESTERIFICATION design of experiment attenuated total reflection infrared spectroscopy partial least square regression
下载PDF
Factorial Experimental Design to Study the Effects of Layers and Fiber Content on Concrete Flexural Behavior
4
作者 Dumbiri H. Odia 《Open Journal of Civil Engineering》 CAS 2023年第1期83-102,共20页
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... 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. 展开更多
关键词 experimental design Concrete Flexural Strength Factorial design of experiments Concrete Fibers Concrete Layers
下载PDF
Ideological and Political Teaching Case Design and Research Based on the Course Simulation Electronic Technology Experiment
5
作者 Meiyi Chen Wei Yang +2 位作者 Xin Hao Shunyu Long Pengfei Zhong 《Journal of Contemporary Educational Research》 2023年第2期37-45,共9页
As critical measures to educate and cultivate people’s morality,“Ideology and Politics of Course”has gradually become the focus in actual undergraduate education research in universities.Targeting the single ideolo... As critical measures to educate and cultivate people’s morality,“Ideology and Politics of Course”has gradually become the focus in actual undergraduate education research in universities.Targeting the single ideological and political education mode and students’lack of interest in experimental courses,this paper,through various links,including pre-class preview,in-class teaching,and after-class data analysis,takes the common emitter single tube amplifier experiment as an example to organically integrate the excavated ideological and political elements with practical operation and carry out teaching case design and practice;realize the improvement of students’learning initiative and problem-analysis ability;and achieve the purpose of cultivating people throughout the whole process and in a comprehensive direction. 展开更多
关键词 Ideology and politics Simulation electronic technology experiment Teaching design
下载PDF
Cavitation Optimization for a Centrifugal Pump Impeller by Using Orthogonal Design of Experiment 被引量:6
6
作者 PEI Ji YIN Tingyun +2 位作者 YUAN Shouqi WANG Wenjie WANG Jiabin 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2017年第1期103-109,共7页
Cavitation is one of the most important performance of centrifugal pumps. However, the current optimization works of centrifugal pump are mostly focusing on hydraulic efficiency only, which may result in poor cavitati... Cavitation is one of the most important performance of centrifugal pumps. However, the current optimization works of centrifugal pump are mostly focusing on hydraulic efficiency only, which may result in poor cavitation performance. Therefore, it is necessary to find an appropriate solution to improve cavitation performance with acceptable efficiency. In this paper, to improve the cavitation performance of a centrifugal pump with a vaned diffuser, the influence of impeller geometric parameters on the cavitation of the pump is investigated using the orthogonal design of experiment (DOE) based on computational fluid dynamics. The impeller inlet diameter D1, inlet incidence angle Aft, and blade wrap angle ~0 are selected as the main impeller geometric parameters and the orthogonal experiment of L9(3"3) is performed. Three-dimensional steady simulations for cavitation are conducted by using constant gas mass fraction model with second-order upwind, and the predicated cavitation performance is validated by laboratory experiment. The optimization results are obtained by the range analysis method to improve cavitation performance without obvious decreasing the efficiency of the centrifugal pump. The internal flow of the pump is analyzed in order to identify the flow behavior that can affect cavitation performance. The results show that D1 has the greatest influence on the pump cavitation and the final optimized impeller provides better flow distribution at blade leading edge. The final optimized impeller accomplishes better cavitation and hydraulic performance and the NPSHR decreases by 0.63m compared with the original one. The presented work supplies a feasible route in engineering practice to optimize a centrifugal pump impeller for better cavitation performance. 展开更多
关键词 cavitation optimization computational fluid dynamics orthogonal design of experiment range analysis
下载PDF
Study on solder joint reliability of ceramic ball grid array component based on design of experiment method 被引量:6
7
作者 吴兆华 黄春跃 周德俭 《China Welding》 EI CAS 2006年第3期68-73,共6页
Four process parameters, pad diameter, stencil thickness, ball diameter and stand-off were chosen as four control factors. By using an L25 (5^6 ) orthogonal array the ceramic ball grid array ( CBGA ) solder joints... Four process parameters, pad diameter, stencil thickness, ball diameter and stand-off were chosen as four control factors. By using an L25 (5^6 ) orthogonal array the ceramic ball grid array ( CBGA ) solder joints which have 25 different combinations of process parameters were designed. The numerical models of all the 25 CBGA solder joints were developed using the Sugrace Evolver. Utilizing the sugrace coordinate exported from the 25 CBGA solder joints numerical models, the finite element analysis models were set up and the nonlinear finite element analysis of the CBGA solder joints under thermal cycles were pegrormed by ANSYS. The thermal fatigue life of CBGA solder joint was calculated using Coffin-Manson equation. Based on the calculated thermal fatigue life results, the range analysis and the variance analysis were pegrormed. The results show that the fatigue life of CBGA solder joint is affected by the pad diameter, the stencil thickness, the ball diameter and the stand-off in a descending order, the best combination of process parameters results in the longest fatigue life is 0.07 mm stand-off, 0.125 mm stencil thickness of, 0.85 mm ball diameter and 0. 89 mm pad diameter. With 95% confidence the pad diameter has a significant effect on the reliability of CBGA solder joints whereas the stand-off, the stencil thickness and the ball diameter have little effect on the reliability of CBGA solder joints. 展开更多
关键词 design of experiment ceramic ball grid array solder joint process parameters finite element analysis
下载PDF
Optimal design of vegetation in residential district with numerical simulation and field experiment 被引量:5
8
作者 洪波 林波荣 +1 位作者 王冰 李树华 《Journal of Central South University》 SCIE EI CAS 2012年第3期688-695,共8页
Vegetation plays a key role in improving wind environment of residential districts,and is helpful for creating a comfortable and beautiful living environment.The optimal design of vegetation for wind environment impro... Vegetation plays a key role in improving wind environment of residential districts,and is helpful for creating a comfortable and beautiful living environment.The optimal design of vegetation for wind environment improvement in winter was investigated by carrying out field experiments in Heqingyuan residential area in Beijing,and after that,numerical simulation with SPOTE(simulation platform for outdoor thermal environment) experiments for outdoor thermal environment of vegetation was adopted for comparison.The conclusions were summarized as follows:1) By comparing the experimental data with simulation results,it could be concluded that the wind field simulated was consistent with the actual wind field,and the flow distribution impacted by vegetation could be accurately reflected;2) The wind velocity with vegetation was lower than that without vegetation,and the wind velocity was reduced by 46%;3) By adjusting arrangement and types of vegetation in the regions with excessively large wind velocity,the pedestrian-level wind velocity could be obviously improved through the simulation and comparison. 展开更多
关键词 wind environment simulation platform for outdoor thermal environment (SPOTE) field experiment optimal design of vegetation SIMULATION
下载PDF
A CASE STUDY IN THE APPLICATION OF SUPERSATURATED DESIGNS TO COMPUTER EXPERIMENTS 被引量:1
9
作者 刘民千 方开泰 《Acta Mathematica Scientia》 SCIE CSCD 2006年第4期595-602,共8页
Supersaturated design is essentially a fractional factorial design in which the number of potential effects is greater than the number of runs. In this article, the supersaturated design is applied to a computer exper... Supersaturated design is essentially a fractional factorial design in which the number of potential effects is greater than the number of runs. In this article, the supersaturated design is applied to a computer experiment through an example of steady current circuit model problem. A uniform mixed-level supersaturated design and the centered quadratic regression model are used. This example shows that supersaturated design and quadratic regression modeling method are very effective for screening effects and building the predictor. They are not only useful in computer experiments but also in industrial and other scientific experiments. 展开更多
关键词 Supersaturated design computer experiment uniform design quadratic regression model
下载PDF
AN EFFICIENT SEQUENTIAL DESIGN FOR SENSITIVITY EXPERIMENTS 被引量:1
10
作者 田玉斌 房永飞 《Acta Mathematica Scientia》 SCIE CSCD 2010年第1期269-280,共12页
In sensitivity experiments, the response is binary and each experimental unit has a critical stimulus level that cannot be observed directly. It is often of interest to estimate extreme quantiles of the distribution o... In sensitivity experiments, the response is binary and each experimental unit has a critical stimulus level that cannot be observed directly. It is often of interest to estimate extreme quantiles of the distribution of these critical stimulus levels over the tested products. For this purpose a new sequential scheme is proposed with some commonly used models. By using the bootstrap repeated-sampling principle, reasonable prior distributions based on a historic data set are specified. Then, a Bayesian strategy for the sequential procedure is provided and the estimator is given. Further, a high order approximation for such an estimator is explored and its consistency is proven. A simulation study shows that the proposed method gives superior performances over the existing methods. 展开更多
关键词 sensitivity experiments extreme quantiles bootstrap principle Bayesianstrategy sequential design
下载PDF
Investigation of the optimum differential gear ratio for real driving cycles by experiment design and genetic algorithm 被引量:1
11
作者 AHMED Aboud 赵长禄 张付军 《Journal of Beijing Institute of Technology》 EI CAS 2015年第1期65-73,共9页
Experiment statistical method and genetic algorithms based optimization method are used to obtain the optimum differential gear ratio for heavy truck that provides best fuel consumption when changing the working condi... Experiment statistical method and genetic algorithms based optimization method are used to obtain the optimum differential gear ratio for heavy truck that provides best fuel consumption when changing the working condition that affects its torque and speed range. The aim of the study is to obtain the optimum differential gear ratio with fast and accurate optimization calculation without affecting drivability characteristics of the vehicle according to certain driving cycles that represent the new working conditions of the truck. The study is carried on a mining dump truck YT3621 with 9 for- ward shift manual transmission. Two loading conditions, no load and 40 t, and four on road real driving cycles have been discussed. The truck powertrain is modeled using GT-drive, and DOE -post processing tool of the GT-suite is used for DOE analysis and genetic algorithm optimization. 展开更多
关键词 heavy trucks fuel consumption OPTIMIZATION design of experiment genetic algo-rithm differential gear ratio
下载PDF
Computer modeling of high-pressure leaching process of nickel laterite by design of experiments and neural networks 被引量:1
12
作者 Milovan Milivojevic Srecko Stopic +2 位作者 Bernd Friedrich Boban Stojanovic Dragoljub Drndarevic 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第7期584-594,共11页
Due to the complex chemical composition of nickel ores, the requests for the decrease of production costs, and the increase of nickel extraction in the existing depletion of high-grade sulfide ores around the world, c... Due to the complex chemical composition of nickel ores, the requests for the decrease of production costs, and the increase of nickel extraction in the existing depletion of high-grade sulfide ores around the world, computer modeling of nickel ore leaching process be- came a need and a challenge. In this paper, the design of experiments (DOE) theory was used to determine the optimal experimental design plan matrix based on the D optimality criterion. In the high-pressure sulfuric acid leaching (HPSAL) process for nickel laterite in "Rudjinci" ore in Serbia, the temperature, the sulfuric acid to ore ratio, the stirring speed, and the leaching time as the predictor variables, and the degree of nickel extraction as the response have been considered. To model the process, the multiple linear regression (MLR) and response surface method (RSM), together with the two-level and four-factor full factorial central composite design (CCD) plan, were used. The proposed re- gression models have not been proven adequate. Therefore, the artificial neural network (ANN) approach with the same experimental plan was used in order to reduce operational costs, give a better modeling accuracy, and provide a more successful process optimization. The model is based on the multi-layer neural networks with the back-propagation (BP) learning algorithm and the bipolar sigmoid activation function. 展开更多
关键词 nickel laterite LEACHING computer simulation design of experiments (DOE) response surface method (RSM) neural networks
下载PDF
Optimization of mechanical properties using D-optimal factorial design of experiment: Electromagnetic stir casting process of A357-SiC nanocomposite 被引量:2
13
作者 Reza MOHAMMADI BADIZI Amir PARIZAD +1 位作者 Mohsen ASKARI-PAYKANI Hamid Reza SHAHVERDI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2020年第5期1183-1194,共12页
Electromagnetic stir casting process of A357-Si C nanocomposite was discussed using the D-optimal design of experiment(DODOE) method. As the main objective, nine random experiments obtained by DX-7 software were perfo... Electromagnetic stir casting process of A357-Si C nanocomposite was discussed using the D-optimal design of experiment(DODOE) method. As the main objective, nine random experiments obtained by DX-7 software were performed. By this method, A357-Si C nanocomposites with 0.5, 1.0 and 1.5 wt.% Si C were fabricated at three different frequencies(10, 35 and 60 Hz) in the experimental stage. The microstructural evolution was characterized by scanning electron and optical microscopes, and the mechanical properties were investigated using hardness and roomtemperature uniaxial tensile tests. The results showed that the homogeneous distribution of Si C nanoparticles leads to the microstructure evolution from dendritic to non-dendritic form and a reduction of size by 73.9%. Additionally, based on DODOE, F-values of 44.80 and 179.64 were achieved for yield stress(YS) and ultimate tensile strength(UTS), respectively, implying that the model is significant and the variables(Si C fraction and stirring frequency) were appropriately selected. The optimum values of the Si C fraction and stirring frequency were found to be 1.5 wt.% and 60 Hz, respectively. In this case, YS and UTS for A357-Si C nanocomposites were obtained to be 120 and 188 MPa(57.7% and 57.9 % increase compared with those of the as-cast sample), respectively. 展开更多
关键词 A357 alloy electromagnetic stir casting Si C nanoparticles mechanical properties D-optimal design of experiments
下载PDF
Design of experiment study on hardness variations in friction stir welding of AM60 Mg alloy 被引量:2
14
作者 S.Richmire K.Hall M.Haghshenas 《Journal of Magnesium and Alloys》 SCIE EI CAS 2018年第3期215-228,共14页
Identification of process parameters,their effects and contributions to the outcomes of the system using experimental approach could be a daunting,time consuming,and costly course.Using proper statistical methods,i.e.... Identification of process parameters,their effects and contributions to the outcomes of the system using experimental approach could be a daunting,time consuming,and costly course.Using proper statistical methods,i.e.,Taguchi method,could significantly reduce the number of required experiments and statistical significance of the parameter can be identified.Friction stir welding is one of those welding techniques with many parameters which have different effects on the quality of the welds.In friction stir welding the tool rotational speed(RPM)and transverse speed(mm/min)influence the strength(i.e.,hardness distribution)of the stirred zone.In this study,these two factors are investigated to determine the effect they will have on the hardness in the stirred zone of the friction stir welds and how the two factors are related to one another for as-cast magnesium alloy AM60 with nominal chemical composition of Mg-(5.5-6.5)Al-(0.24-0.6)Mn-0.22Zn-0.1Si.Experimental data was taken at three different tool rotational speeds and three different transverse speeds.The data obtained was then analyzed using a 32 factorial design to find the contribution of these parameters.It was determined that both tool rotational speed and transverse speed possess significant effects on the stir zone hardness.Also,the interactions between the two factors were statistically assessed. 展开更多
关键词 AM60 Mg alloy design of experiment(DOE) Statistical method Friction stir welding
下载PDF
Application of Monte-Carlo statistical experiments in design of ocean engineering - Estimating the parameters, models and probabilities 被引量:2
15
作者 Liu Defu, Shi Jiangang and Zhou Zhigang Department of Ocean Engineering and Naval Architecture, Tianjin University. Tianjin, China Business & Project Division China Offshore Industrial Corporation (COIC).No. 10 Beixiaojie,Yuetan,BeijingsChina 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1990年第4期587-597,共11页
Recently, some results have been acquired with the Monte- Carlo statistical experiments in the design of ocean en gineering. The results show that Monte-Carlo statistical experiments can be widely used in estimating t... Recently, some results have been acquired with the Monte- Carlo statistical experiments in the design of ocean en gineering. The results show that Monte-Carlo statistical experiments can be widely used in estimating the parameters of wave statistical distributions, checking the probability model of the long- term wave extreme value distribution under a typhoon condition and calculating the failure probability of the ocean platforms. 展开更多
关键词 Estimating the parameters Application of Monte-Carlo statistical experiments in design of ocean engineering
下载PDF
Analyzing Laser-Welded NiTi-NiTi-Joints for Actuator Applications Using Design of Experiments 被引量:1
16
作者 Dennis Otibar Christian Rathmann +2 位作者 Konstantin Lygin Dieter Kreimeier Peter Szymansky 《Journal of Mechanics Engineering and Automation》 2015年第2期76-81,共6页
One promising joining method for NiTi-SMA (shape memory alloy)-components is laser welding. This joining technology bears huge potential regarding process automation and mechanical properties as well as durability, ... One promising joining method for NiTi-SMA (shape memory alloy)-components is laser welding. This joining technology bears huge potential regarding process automation and mechanical properties as well as durability, especially within the field of small- and medium-sized actuators. However, there is still need for research due to unsolved issues influencing the microstructure and thus effecting mechanical properties as well as SMA-characteristics of these joints. Therefore, the purpose of this paper is the evaluation of quality parameters of NiTi-NiTi-wire-joints. For this purpose, design of experiments with a fractional factorial design is used for the investigation, because of its high potential to decrease experimental effort. This paper provides a basis for future research in the field of SMA-actuators and joining. 展开更多
关键词 SMA shape memory actuators NiTi-NiTi-joints laser welding joining design of experiments.
下载PDF
Design of Calibration Experiments for Identification of Manipulator Elastostatic Parameters 被引量:1
17
作者 Alexandr Klimchik Anatol Pashkevichl +2 位作者 Yier Wu Stephane Caro Benoit Furet 《Journal of Mechanics Engineering and Automation》 2012年第9期531-542,共12页
The paper is devoted to the elastostatic calibration of industrial robots, which is used for precise machining of large-dimensional parts made of composite materials. In this technological process, the interaction bet... The paper is devoted to the elastostatic calibration of industrial robots, which is used for precise machining of large-dimensional parts made of composite materials. In this technological process, the interaction between the robot and the workpiece causes essential elastic deflections of the manipulator components that should be compensated by the robot controller using relevant elastostatic model of this mechanism. To estimate parameters of this model, an advanced calibration technique is applied that is based on the non-linear experiment design theory, which is adopted for this particular application. In contrast to previous works, it is proposed a concept of the user-defined test-pose, which is used to evaluate the calibration experiments quality. In the frame of this concept, the related optimization problem is defined and numerical routines are developed, which allow generating optimal set of manipulator configurations and corresponding forces/torques for a given number of the calibration experiments. Some specific kinematic constraints are also taken into account, which insure feasibility of calibration experiments for the obtained configurations and allow avoiding collision between the robotic manipulator and the measurement equipment. The efficiency of the developed technique is illustrated by an application example that deals with elastostatic calibration of the serial manipulator used for robot-based machining. 展开更多
关键词 Industrial robot elastostatic calibration experiment design industry-oriented performance measure test-pose basedapproach.
下载PDF
Multidisciplinary Design and Optimization of Satellite Launch Vehicle Using Latin Hypercube Design of Experiments 被引量:1
18
作者 AMER Farhan Rafique QASIM Zeeshan 《Computer Aided Drafting,Design and Manufacturing》 2009年第1期1-7,共7页
The design of new Satellite Launch Vehicle (SLV) is of interest, especially when a combination of Solid and Liquid Propulsion is included. Proposed is a conceptual design and optimization technique for multistage Lo... The design of new Satellite Launch Vehicle (SLV) is of interest, especially when a combination of Solid and Liquid Propulsion is included. Proposed is a conceptual design and optimization technique for multistage Low Earth Orbit (LEO) bound SLV comprising of solid and liquid stages with the use of Genetic Algorithm (GA) as global optimizer. Convergence of GA is improved by introducing initial population based on the Design of Experiments (DOE) Technique. Latin Hypercube Sampling (LHS)-DOE is used for its good space filling properties. LHS is a stratified random procedure that provides an efficient way of sampling variables from their multivariate distributions. In SLV design minimum Gross Lift offWeight (GLOW) concept is traditionally being sought. Since the development costs tend to vary as a function of GLOW, this minimum GLOW is considered as a minimum development cost concept. The design approach is meaningful to initial design sizing purpose for its computational efficiency gives a quick insight into the vehicle performance prior to detailed design. 展开更多
关键词 multidisciplinary design and optimization satellite launch vehicle solid propulsion liquid propulsion latin hypercube sampling design of experiments
下载PDF
Bayesian Variable Selection for Mixture Process Variable Design Experiment 被引量:1
19
作者 Sadiah M. A. Aljeddani 《Open Journal of Modelling and Simulation》 2022年第4期391-416,共26页
This paper discussed Bayesian variable selection methods for models from split-plot mixture designs using samples from Metropolis-Hastings within the Gibbs sampling algorithm. Bayesian variable selection is easy to im... This paper discussed Bayesian variable selection methods for models from split-plot mixture designs using samples from Metropolis-Hastings within the Gibbs sampling algorithm. Bayesian variable selection is easy to implement due to the improvement in computing via MCMC sampling. We described the Bayesian methodology by introducing the Bayesian framework, and explaining Markov Chain Monte Carlo (MCMC) sampling. The Metropolis-Hastings within Gibbs sampling was used to draw dependent samples from the full conditional distributions which were explained. In mixture experiments with process variables, the response depends not only on the proportions of the mixture components but also on the effects of the process variables. In many such mixture-process variable experiments, constraints such as time or cost prohibit the selection of treatments completely at random. In these situations, restrictions on the randomisation force the level combinations of one group of factors to be fixed and the combinations of the other group of factors are run. Then a new level of the first-factor group is set and combinations of the other factors are run. We discussed the computational algorithm for the Stochastic Search Variable Selection (SSVS) in linear mixed models. We extended the computational algorithm of SSVS to fit models from split-plot mixture design by introducing the algorithm of the Stochastic Search Variable Selection for Split-plot Design (SSVS-SPD). The motivation of this extension is that we have two different levels of the experimental units, one for the whole plots and the other for subplots in the split-plot mixture design. 展开更多
关键词 Variable Selection Bayesian Analysis Mixture experiment Split-Plot design
下载PDF
Polylactic Acid (PLA) Foaming: Design of Experiments for Cell Size Control 被引量:1
20
作者 Miada Abubaker Osman Nick Virgilio +1 位作者 Mahmoud Rouabhia Frej Mighri 《Materials Sciences and Applications》 2022年第2期63-77,共15页
In this study, a design of experiments (DoE) approach was used to develop a PLA open-cell foam morphology using the compression molding technique. The effect of three molding parameters (foaming time, mold opening tem... In this study, a design of experiments (DoE) approach was used to develop a PLA open-cell foam morphology using the compression molding technique. The effect of three molding parameters (foaming time, mold opening temperature, and weight concentration of the ADA blowing agent) on the cellular structure was investigated. A regression equation relating the average cell size to the above three processing parameters was developed from the DoE and the analysis of variance (ANOVA) was used to find the best dimensional fitting parameters based on the experimental data. With the help of the DoE technique, we were able to develop various foam morphologies having different average cell size distribution levels, which is important in the development of open-cell PLA scaffolds for bone regeneration for which the control of cell morphology is crucial for osteoblasts proliferation. For example, at a constant ADA weight concentration of 5.95 wt%, we were able to develop a narrow average cell size distribution ranging between 275 and 300 μm by varying the mold opening temperature between 106°C and 112°C, while maintaining the foaming time constant at 8 min, or by varying the mold foaming time between 6 and 11 min and maintaining the mold opening temperature at 109°C. 展开更多
关键词 PLA Open-Cell Foam design of experiments Cell Size Distribution
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部