Optimum design of welded structures

This article presents the cost calculation system developed by us to determine the cost of a welded structure. In the paper the design, fabrication and economy are linked together in the optimization system. Two tubular truss applications show, that the reduction of cost can be significant

Efficient algorithms for optimization of objects and systems

Efficient algorithms are needed for optimization of objects and systems, because the user would like to be sure that the optimum is global. The paper shows a very well scalable discrete firefly algorithm, developed for solving a supplier selection problem. The built in general reduced gradient and evolutionary algorithms of the Excel solver are also compared solving this problem. The results show that the firefly algorithm solves the problem in the fragment of the running time of the evolutionary algorithm. In the second part of the article, a mathematical model was formulated to solve the fixed destination multidepot multiple tour multiple traveling salesmen problem (mdmMTSP)

Fuzzy Optimization of a Belt-conveyor Bridge

In the structural optimization of a ring-stiffened cylindrical shell the unknown variables are the shell thickness as well as the thickness and the number of flat rings. The shell diameter enables to realize a belt-conveyor structure inside of the shell. The uniformly distributed vertical load consists of dead and live load. The design constraints relate to the local shell buckling strength, to the panel ring buckling and to the deflection of the simply supported bridge. The cost function includes the material and fabrication costs. The fabrication cost function is formulated according to the fabrication sequence and includes also the cost of forming of shell elements into the cylindrical shape as well as the cost of cutting of the flat plate ring-stiffeners. As an alternative to safety factors one may try to describe the uncertain data via a non-probabilistic description of uncertainty, in particular the fuzzy-set based analysis. Several procedures are described and the optimum design level can be obtained either based on failure possibility or of membership value satisfaction. The fuzzy-based optimization becomes a sequential minimization of unconstrained convex scalar functions, from which a Pareto solution is obtained. A branch and bound procedure is associated with this algorithm to provide a discrete solution

Comparison of aggregationwebparts in MOSS 2007

En typisk funktion på startsidan till många webbportaler är den webbdel som presenterar exempelvis desenaste blogginläggen, nyheterna eller händelserna som har lagts till på webbplatsen. Dessa funktioner ärkända som aggreggeringswebbdelar. Eftersom startsidan är den sida som besöks mest jämfört med alla andrawebbsidor i portalen innebär det i sin tur att denna funktion utnyttjas väldigt ofta.Detta arbete syftar till att finna ett antal olika metoder som kan användas för att uppnå denna funktion ochatt ta reda på hur väl dessa webbdelar presterar.Denna rapport presenterar både de olika metoder som fanns och resultaten på en systematisk testning avdessa. Resultaten av testerna presenteras på ett överskådligt sätt.Slutligen dras slutsatser angående resultaten. Resultaten förespråkar inte en specifik metod, den metod somlämpar sig bäst för varje enskild sammanhang avgörs till största del av andra faktorer såsom frekvens avbesökare eller ändringar på innehållet som metoden söker igenom