Detab is a company in Jönköping that develops systems for feeding parts for robots and packaging processes. To control the flow of parts on their vibratory feeders, Detab uses different carpets with angled straws. The two mainly used carpets have been discontinued and must now be replaced. A newly emerged option is a contender in replacing one of the carpets. The new white carpet is completely additively manufactured. To compare the old carpet and the new carpet, data is needed to show how different settings affect the flow of the parts. Through design of experiments and response surface methods, tests can be performed in a systematic and mathematical way compare the performance of different settings. Some basic parameters were defined to begin the investigation of which design of experiments method would be used to best compare the carpets. The parameters defined where the parts that would be used in the tests, the factors that were to be adjusted during the tests, the maximum and minimum values of the selected factors and how the results would be measured. Different methods were tested, and finally optimal design was chosen and executed using the program Design-Expert. The completed tests resulted in response surfaces that were constructed using Design-Expert. These response surfaces were analyzed and several similarities and differences between the different carpets were observed. Primarily, it was found that the green carpet had more settings that resulted in a flow above 0 parts/minute. Using Design-Expert, the response surfaces could be analyzed to find the optimal settings and their expected response. These points and more were then compared with tests performed afterwards to see if the expected values matched reality. It turned out that there were some uncertainties in how well the surfaces could predict the response in comparison with reality. Based on the experiments carried out, recommendations were made on how the company should proceed to be able to assess whether the new carpet is worth using in future construction of their machines.

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A procedure for generating a customized weight function for wing bending material weight of a High Speed Civil Transport (HSCT) is described. The weight function is based on HSCT configuration parameters. A response surface methodology is used to fit a quadratic polynomial to data gathered from a large number of structural optimizations. To reduce the time of performing a large number of structural optimizations, coarse-grained parallelization with a master-slave processor assignment on an Intel Paragon computer is used. The results of the structural optimization are noisy. Noise reduction in the structural optimization results is discussed. It is shown that the response surface filters out this noise. A statistical design of experiments technique is used to minimize the number of required structural optimizations and to maintain accuracy. Simple analysis techniques are used to find regions of the design space where reasonable HSCT designs could occur, thus customizing the weight function to the design requirements of the HSCT, while the response surface itself is created employing detailed analysis methods. Analysis of variance is used to reduce the number of polynomial terms in the response surface model function. Linear and constant corrections based on a small number of high fidelity results are employed to improve the accuracy of the response surface model. Configuration optimization of the HSCT employing a customized weight function is compared to the configuration optimization of the HSCT with a general weight function. / Ph. D.

This dissertation presents an empirical approach to identifying decisions for adapting cognitive radio parameters with no a priori knowledge of the environment. Cognitively inspired radios, attempt to combine observed metrics of system performance with artificial intelligence decision-making algorithms. Current architectures trend towards hybrid combinations of heuristics, such as genetic algorithms (GA) and experiential methods, such as case-based reasoning (CBR). A weakness in the GA is its reliance on limited mathematical models for estimating bit error rate, packet error rate, throughput, and signal-to-noise ratio. The CBR approach is similarly limited by its dependency on past experiences. Both methods have potential to suffer in environments not previously encountered. In contrast, the statistical methods identify performance estimation models based on exercising defined experimental designs. This represents an experiential decision-making process formed in the present rather than the past. There are three core contributions from this empirical framework: 1) it enables a new approach to decision making based on empirical estimation models of system performance, 2) it provides a systematic method for initializing cognitive engine configuration parameters, and 3) it facilitates deeper understanding of system behavior by quantifying parameter significance, and interaction effects. Ultimately, this understanding enables simplification of system models by identifying insignificant parameters. This dissertation defines an abstract framework that enables application of statistical approaches to cognitive radio systems regardless of its platform or application space. Specifically, it assesses factorial design of experiments and response surface methodology (RSM) to an over-the-air wireless radio link. Results are compared to a benchmark GA cognitive engine. The framework is then used for identifying software-defined radio initialization settings. Taguchi designs, a related statistical method, are implemented to identify initialization settings of a GA. / Ph. D.

In the constantly changing field of engineering and design, achieving solutions that are both resilient and optimized is crucial. This thesis introduces a robust design methodology (RDM) that integrates statistical concepts and Finite Element Analysis (FEA) to enhance the product reliability and durability. Altair Hyperstudy is used for design exploration, and it examines how changes in geometry and material properties influence the IKEA Wall-Mounting shelving unit. The objective is to efficiently parameterize geometric shapes, compare different Design of Experiments (DOE) methodologies, identify key input variables impacting outputs, and generate a response surface model based on training data. The parameterization of geometric shapes is achieved using the morphing tool in Altair Hypermesh, while the design exploration is conducted using Full factorial, Fractional factorial V, IV and III approaches with selected resolutions. A space-filling modified extensive lattice sequence design (MELS) is employed to examine the entire design space, providing input for the development of the response surface methodology (RSM). Finally, the RSM is developed for all design variables and the quality of fit is assessed. The methodology described is used to explore the design space and determine which parameters influence the system’s output response, ensuring these parameters are considered during the design phase.

With the intention of improving process efficiency and product quality, Design of Experiments (DoE) is often applied in industry as a tool for engineers in planning experiments and product design. One of the methods in DoE is the Taguchi method that provides a practical procedure to design experiments with an appropriate number of tests for identifying optimal parametric settings of products. The purpose of this study is to investigate how Design of Experiments, specifically the Taguchi method, can be applied to analyze the performance of the lubricants used to stainless fasteners which are common products in various industries. The study has been implemented at the case company which manufactures stainless fasteners. Combining with qualitative and quantitative methods, this thesis work started from reviewing the previous research on DoE, the Taguchi method and various analysis tools as well as information on lubricants. Experiments were designed based on observations, interview, and literature collection. The actual tests were carried out on the case company's wax process where lubricants with different levels for the respective parameters were applied to screws and nuts. The fasteners were tested in a friction machine and UV lamp at the case company. The implemented experiments and data analysis have demonstrated which levels for each parameter of the lubricant resulted in the least friction. The parameters considered in the experiments are mixing ratio, number of dips and time in dips, which have varying degrees of influence on friction. The outcomes contribute to improved process efficiency and product quality within the steel industry and similar sectors. The visualization of the lubricant by UV lamp confirmed that the coating varied according to the levels of the parameters. The theoretical contribution can facilitate further research while the practical contribution provides an approach for experiments in quality improvement on lubricants. The thesis work has also identified the need for further research into the drying process after lubricant application and the use of UV lamp to improve control of lubricant smoothness.

This thesis aims at a deeper understanding of Supercritical Fluid Chromatography (SFC). Although preparative SFC has started to replace Liquid Chromatography (LC) in the pharmaceutical industry - because of its advantages in speed and its less environmental impact - fundamental understanding is still lacking. Therefore there is no rigid framework to characterize adsorption or to understand the impact of changes in operational conditions.   In Paper I we demonstrated, after careful system verification, that most methods applied to determine adsorption isotherms in LC could not be applied directly in SFC. This was mainly due to operational differences and to the fact that the fluid is compressible which means that everything considered constant in LC varies in SFC.   In Paper II we showed that the most accurate methods for adsorption isotherm determination in LC, the so called plateau methods, do not work properly for SFC. Instead, methods based on overloaded profiles should be preferred.   In Paper III a Design of Experiments approach was successfully used to quantitatively describe the retention behavior of several solutes and the productivity of a two component separation system. This approach can be used to optimize SFC separations or to provide information about the separation system.   In Paper IV severe peak distortion effects, suspected to arise from injection solvent and mobile phase fluid mismatches, were carefully investigated using experiments and simulations. By this approach it was possible to examine the underlying reasons for the distortions, which is vital for method development.   Finally, in Paper V, the acquired knowledge from Paper I-IV was used to perform reliable scale-up in an industrial setting for the first time. This was done by carefully matching the conditions inside the analytical and preparative column with each other. The results could therefore provide the industry with key knowledge for further implementation of SFC. / This thesis aims at a deeper understanding of Supercritical Fluid Chromatography (SFC). Although preparative SFC has started to replace Liquid Chromatography (LC) in the pharmaceutical industry - because of its advantages in speed and its less environmental impact - fundamental understanding is still lacking. Therefore there is no rigid framework to characterize adsorption or to understand the impact of changes in operational conditions.   In Paper I-II it was demonstrated why most methods applied to determine adsorption isotherms in LC could not be applied directly for SFC. Methods based on extracting data from overloaded profiles should be preferred.   In Paper III a Design of Experiments approach was successfully used to quantitatively describe the behavior of several solutes in a separation system. This approach can be used to optimize SFC separations or to provide information about the separation system.   In Paper IV severe peak distortion effects often observed in SFC were carefully investigated and explained using experiments and simulations.   Finally, in Paper V, the prerequisites for performing reliable and predictable scale-up of SFC were investigated by small and large scale experiments. / <p>Paper 4 ("Evaluation of scale-up from analytical to preparative...") ingick som manuskript med samma titel i avhandlingen. Nu publicerad. </p>