Taguchi Algorithm Research Articles

Statistical analysis of calcium sulfate scaling under boiling heat transfer

Generally, fouling experiments are expensive and time consuming tests since they are maturated during long period of time. Therefore, it is necessary to obtain more information performing fewer experiments. In this study, statistical analysis of calcium sulfate scaling during subcooled flow boiling condition has been performed using Taguchi algorithm. Totally, 16 experiments were performed having four operating parameters each one at two levels. Furthermore, the interactions between the operating parameters were also considered. Results demonstrated that the concentration of calcium sulfate has the greatest effect (greater than 69%) on the fouling rate. Meanwhile, optimum operating conditions in which the least fouling rate was observed were found using analysis of variance (ANOVA). The prediction of fouling rate at these optimum conditions shows a deviation of about 5% from the experimental result.

Multi-objective green supply chain optimization with a new hybrid memetic algorithm using the Taguchi method

The aim of most supply chain optimization problems is to minimize the total cost of the supply chain. However, since environmental protection is of concern to the public, a green supply chain, because of its minimum effect on nature, has been seriously considered as a solution to this concern. This paper addresses the modeling and solving of a supply chain design for annual cost minimization, while considering environmental effects. This paper considers the cost elements of the supply chain, such as transportation, holding and backorder costs, and also, the environmental effect components of the supply chain, such as the amount of NO2, CO and volatile organic particles produced by facilities and transportation in the supply chain. Considering these two components (cost and environmental effects), we propose a multi-objective optimization problem. In this model, the facilities and transportation options have a capacity constraint and, at each level of the chain, we have several transportation options with different costs. We utilize a memetic algorithm in combination with the Taguchi method to solve this complex model. We also propose a novel decoding method and priority based algorithm for coding the solution chromosome. The performance of the proposed solution method has been examined against the hybrid genetic Taguchi algorithm (GATA) on a set of numeric instances, and results indicate that the proposed method can effectively provide better results than previous solution procedures.

Effect of the addition of potassium and lithium in Pt–Sn/Al2O3 catalysts for the dehydrogenation of isobutane

Dehydrogenation of isobutane (iC4) to isobutene has recently received considerable attention because of the increasing demand for methyl tertiary butyl ether (MTBE) and ethyl tertiary butyl ether (ETBE), as additives for gasoline to increase the octane number and to substitute lead. Among several catalysts, Pt–Sn/γ-Al2O3 catalyst is one of the most suitable ones. In this study, Pt–Sn, Pt–Sn–K and Pt–Sn–Li catalysts supported on γ-Al2O3 have been investigated. The catalysts were prepared by co-impregnation using H2PtCl6, SnCl2 as the metal precursors and K2CrO4 and LiOH as the promoters. The obtained catalysts were characterized by TPR and XRD techniques. Reaction temperature, feed flow rate (Q), iC4/H2 ratio and the catalyst type were the main variables that were investigated. Initially, primary experiments were carried out for the identification of the optimum range of operating variables, then, Taguchi's algorithm was employed to design the experiment. The results revealed that the Pt–Sn–K catalyst showed higher selectivity than Pt–Sn–Li. Under the optimum operating conditions i.e. at 550 °C, feed flow rate of 50 cm3/min and iC4/H2 ratio of 1/3, selectivity toward isobutene of higher than 90% was achieved with the corresponding conversion values of about 15%.

Determination of the Optimum Operating Conditions for Direct Synthesis of Dimethyl Ether from Syngas

The optimum operating conditions of a single – step synthesis of dimethyl ether (DME) from synthesis gas has been determined. The bifunctional catalyst has been prepared by physically mixing of a commercial methanol catalyst (KMT Co.) and a dehydration catalyst (H-MF-90) which has been characterized by XRD, XRF and BET techniques. Catalytic synthesis of dimethyl ether from synthesis gas was evaluated in agitated slurry micro reactor in different ranges of operating conditions which were determined by experimental design according to Taguchi algorithm. The range of operating conditions were chosen as follows: H2/CO mole ratio in feed varying from 0.26 to 1.5, the pressure varying from 10 to 50 bar, the temperature varying from 200 to 240 ºC and weight ratio of methanol catalyst to dehydration catalyst from 0.67 to 4. The experiments have been conducted for different operating conditions at fixed impeller speed equal to 1600rpm and space velocity equal to 500 ml/gcat.h. Considering the results of experiments, optimum conditions for direct synthesis of DME were predicted as follows: T=240 ºC, P=33.3 Bar, H2/CO=1.5 and weight ratio of methanol catalyst to dehydration catalyst equal to 3.

A [formula omitted]-adic point counting algorithm for elliptic curves on legendre form

In 2000 T. Satoh gave the first p - adic point counting algorithm for elliptic curves over finite fields. Satoh' s algorithm was followed by the Satoh–Skjernaa–Taguchi algorithm and furthermore by the arithmetic–geometric mean and modified SST algorithms for characteristic two only. All four algorithms are important to Elliptic Curve Cryptography. In this paper, we present the general framework for p -adic point counting and we apply it to elliptic curves on Legendre form. We show how the λ - modular polynomial can be used for lifting the curve and Frobenius isogeny to characteristic zero and we show how the associated multiplier gives the action of the lifted Frobenius isogeny on the invariant differential. The result is a point counting algorithm for elliptic curves on Legendre form. The algorithm runs in a time complexity of O ( n 2 μ + 1 / ( μ + 1 ) ) for fixed p and a space complexity of O ( n 2 ) where p n is the field size. We include results from experimeriments in characteristic p = 3 , 5 , … , 19 .