202,266 research outputs found
Parameter optimization by Taguchi Methods for finishing advanced ceramic balls using a novel eccentric lapping machine
No full textThe final finishing process of advanced ceramic balls used in hybrid precision bearings constitutes two-thirds of the total manufacturing cost, and hence effective and economic finishing methods and processes are critical to their widespread application. A novel eccentric lapping machine is designed and manufactured. Hot isostatically pressed silicon nitride ball blanks (diameter 13.25 mm) are used to investigate the feasibility of accelerating the ball finishing process while maintaining high surface quality. Taguchi methods are used during the first step of finishing to optimize lapping parameters; the L9 (3(4)) four-parameter, three-level orthogonal array is used to design the experiment. Experimental results reveal that this novel eccentric lapping method is very promising; a material removal rate of 40 mum/h is achievable. The optimum lapping condition is found to be high speed, high load and high paste concentration with 60 mum diamond particles. The analysis of variance shows that the most significant lapping parameter is lapping load, which accounts for 50 per cent of the total, followed by lapping speed (31 per cent); the particle size and paste concentration only account for 12 per cent and 7 per cent respectively. A comparison with previous lapping experiments and the mechanism of material removal are also discussed briefly
The application of Taguchi approach to optimise the processing conditions on bonnet polishing of CoCr
No full textThis paper applied the Taguchi approach to investigate the effects of each polishing
parameter and obtain the optimal processing conditions for CoCr alloy polishing. The polishing medium was 1µm diamond paste with Microcloth(polishing cloth). Surface finish parameter Sa was chosen as criterion for optimization. The experimental result indicates that the optimal polishing condition for CoCr alloy polishing is 5deg of precess angle, 800 rpm of head speed, 0.2mm of tool offset and 1.5 bar of tool pressure. With this optimal condition, a confirmatory experiment was conducted. The surface roughness Sa reduced from initial 24nm to 7nm and reduction ratio was 72.5% which was very close to the estimated ratio 64%
Using Taguchi method to optimize welding pool of dissimilar laser welded components
No full textIn the present work CO2 continuous laser welding process was successfully applied and optimized for joining a dissimilar AISI 316 stainless steel and AISI 1009 low carbon steel plates. Laser power, welding speed, and defocusing distance combinations were carefully selected with the objective of producing welded joint with complete penetration, minimum fusion zone size and acceptable welding profile. Fusion zone area and shape of dissimilar austenitic stainless steel with ferritic low carbon steel were evaluated as a function of the selected laser welding parameters. Taguchi approach was used as statistical design of experiment (DOE) technique for optimizing the selected welding parameters in terms of minimizing the fusion zone. Mathematical models were developed to describe the influence of the selected parameters on the fusion zone area and shape, to predict its value within the limits of the variables being studied. The result indicates that the developed models can predict the responses satisfactorily
A Taguchi method application for the part routing selection in Generalized Group Technology: A case Study
No full textCellular manufacturing (CM) is an important application of group technology (GT) that can be used to enhance both flexibility and efficiency in today’s small-to-medium lot production environment. The crucial step in the design of a CM system is the cell formation (CF) problem which involves grouping parts into families and machines into cells. The CF problem are increasingly complicated if parts are assigned with alternative routings (known as generalized Group Technology problem). In most of the previous works, the route selection problem and CF problem were formulated in a single model which is not practical for solving large-scale problems. We suggest that better solution could be obtained by formulating and solving them separately in two different problems. The aim of this case study is to apply Taguchi method for the route selection problem as an optimization technique to get back to the simple CF problem which can be solved by any of the numerous CF procedures. In addition the main effect of each part and analysis of variance (ANOVA) are introduced as a sensitivity analysis aspect that is completely ignored in previous research.Cellular Manufacturing; generalized Group Technology; route selection problem; Taguchi method; ANOVA; sensitivity analysis
Custos da qualidade : planejamento economico dos graficos de controle por atributos e modelos correlatos
No full textTese (doutorado) - Universidade Federal de Santa Catarina, Centro TecnologicoRevisão e análise dos modelos de planejamento econômico dos gráficos de controle por atributos e modelos correlatos existentes. Agrupamento dos modelos em conjuntos de enfoques semelhantes, com base, especialmente, na formulação da função custo/perda, seus pressupostos básicos e número de parâmetros de custo/risco envolvidos. Indicação do modelo que melhor se adapta às necessidades, características e capacidades de um sistema produtivo. Instruções adicionais, para a tomada de decisão, com base em análise de sensibilidade dos modelos. Estudo comparativo entre o modelo de Taguchi e outros que lhe são compatíveis
[3 Cortical Blood Flow and Oxygenation Abstracts]
No full textThree presentations stapled together:
The Changes of Cortical Blood Flow and Cortical Oxygen Tension in Focal Ischemia. M. Kaminoga, M.D., Y. Taguchi, G. Austin, M.D. Conference presentation. American College of Surgeon Annual Meeting, January 28, 1984. NOTE 2nd page of this abstract not present in this file. 2nd page is present in Individual presentation posted separately.
Effect of Hypoxia and Hyperoxia of NADH Redox State and Cortical PO2 in the Rabbit. Y Taguchi, M.D.; M. Kaminogo, M.D.; G. Austin, M.D. Conference Presentation. Southern California Chapter, American College of Surgeons, Santa Barbara, Calif, January 28, 1984.
Autoregulation of Cortical Blood Flow and Cortical Oxygen Tension in Relation to Cortical Oxidative Metabolism. Y. Taguchi. M. Kaminogo, G. Austin. Conference Presentation. Federation of Western Societies of Neurological Sciences, Napa, Calif, February 23, 1984
Comparison of Evolutionary Optimization Algorithms for FM-TV Broadcasting Antenna Array Null Filling
No full textBroadcasting antenna array null filling is a very
challenging problem for antenna design optimization. This paper
compares five antenna design optimization algorithms (Differential
Evolution, Particle Swarm, Taguchi, Invasive Weed, Adaptive
Invasive Weed) as solutions to the antenna array null filling
problem. The algorithms compared are evolutionary algorithms
which use mechanisms inspired by biological evolution, such as
reproduction, mutation, recombination, and selection. The focus of
the comparison is given to the algorithm with the best results,
nevertheless, it becomes obvious that the algorithm which produces
the best fitness (Invasive Weed Optimization) requires very
substantial computational resources due to its random search
nature
A Comparison Study of Mahalanobis-Taguchi System and Neural Network for Multivariate Pattern Recognition
No full textThe Mahalanobis-Taguchi System is a diagnosis and predictive method for analyzing patterns in multivariate cases. The goal of this study is to compare the ability of the Mahalanobis-Taguchi System and a neural network to discriminate using small data sets. We examine the discriminant ability as a function of data set size using an application area where reliable data is publicly available. The study uses the Wisconsin Breast Cancer study with nine attributes and one class
A hierarchical Bayesian approach to robust parameter design.
No full textThe goal of robust parameter design experiments is to identify significant location and dispersion factors that can be used to set the mean response at the target level and to decrease the sensitivity of the response to uncontrolled noise factors. We present a hierarchical Bayesian model and use empirical Bayes priors to find the active factors and to get reliable estimates of the location and dispersion parameters. The approach is particularly useful when the design points are not replicated, a case which is challenging with standard procedures.Bayesian; Credibility or posterior probability intervals; Design; Empirical Bayes priors; Factors; Gibbs sampling; Hierarchical Bayesian model; Location and dispersion factors; Model; Noise; Parameters; Sensitivity; Taguchi experiments; WinBUGS;
- …
