Multi-objective optimal design of braced frames using hybrid genetic and ant colony optimization

In this article, multi-objective optimization of braced frames is investigated using a novel hybrid algorithm. Initially, the applied evolutionary algorithms, ant colony optimization （ACO） and genetic algorithm （GA） are reviewed, followed by developing the hybrid method. A dynamic hybridization of GA and ACO is proposed as a novel hybrid method which does not appear in the literature for optimal design of steel braced frames. Not only the cross section of the beams, columns and braces are considered to be the design variables, but also the topologies of the braces are taken into account as additional design variables. The hybrid algorithm explores the whole design space for optimum solutions. Weight and maximum displacement of the structure are employed as the objective functions for multi-objective optimal design. Subsequently, using the weighted sum method （WSM）, the two objective problem are converted to a single objective optimization problem and the proposed hybrid genetic ant colony algorithm （HGAC） is developed for optimal design. Assuming different combination for weight coefficients, a trade-offbetween the two objectives are obtained in the numerical example section. To make the final decision easier for designers, related constraint is applied to obtain practical topologies. The achieved results show the capability of HGAC to find optimal topologies and sections for the elements.

Changes in biochemical properties of tomato(cv.240)affected by combination of blue/red optical spectra and Calfomyth spray(Ca and P)

The levels of antioxidant activity and vitamins can change with varying ratios of different wavelengths.This study was conducted as a pot experiment under soilless culture conditions in order to investigate the interactive effects of light supplementation and nutrition(calfomyth solution)on some qualitative traits of tomato fruit.The research was carried out as a split-plot experiment based on a completely randomized design with three light treatments including without supplementary light(control),60% red light+40% blue light and 90%red light+10% blue light.There were two nutritional treatments including no spraying with calfomyth as commercial fertilizer and foliar application with a concentration of 2 mg/L in three replicates.According to the results,the amounts of vitamin C(16.1 mg/g FW fruit),soluble solids(12.33 mg/g FW fruit),and lycopene(2.95 mg/g FW fruit)were all uppermost by the effect of a higher percentage of red light treatment.Higher percentage of the blue light resulted in the highest leaf chlorophyll content(38.4 mg/g FW leaf),but supplementary light treatments had no significant effects on the titratable acidity.Nutrition(calfomyth foliar application)showed positive impacts on all treatment traits compared to control.Beta-carotene content was affected by none of the treatments with no significant differences.According to this research,it can be expected that the use of complementary light treatments and calfomyth foliar spray may have positive effects on most of the qualitative traits in tomato fruit(cv.240).