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In this paper we study optimization of multistage drying process in fluidized bed. The drying of fine particles in fluidized bed is very effective operation because of good contact of phases and a large interfacial surface. Using a relatively high gas velocity improves conditions of mass and heat transfers but a portion of gas begins to flow as bubbles or canals, so an energy carried by this gas is not used efficiently. This is a reason to search for best operating parameters to minimize cost or to maximize efficiency of the process. A method of determining optimal parameters of drying gas (flowrate, temperature and humidity) is described in this paper. As a performance index, i.e. function being optimized, we apply a function describing the exergy input in the drying process. This function consists of three parts, the first two describing the thermal and chemical exergy of gas whereas the third one referring to investment costs expressed in exergy units. The chemical exergy of gas is connected with the difference between gas humidity and ambient humidity. In the optimization calculations we search for a minimum of exergy consumption Any effective method of optimization involves an algorithm of maximum principle for multistage problems. The earliest algorithms of this sort was the Katz' and Fan's algorithm. As it is less suitable for our purposes due to its undefined symplectic structure, we apply a modification of Sieniutycz's and Szwast's algorithm with a constant Hamiltonian (formally similar to the well-know continuous algorithm of Pontryagin). In this paper a modification of the basis algorithm is applied. This modification admits constrained intervals of time. In our calculations we take into consideration the bed hydrodynamics and kinetics of transport processes To describe behavior of fluidized bed we use the well-known two-phase model of Kunii and Levenspiel In this model, the gas excess flows in form of bubbles. The heat and mass transfer between the solid and gas as well between the dense phase (with gas and solid) and bubble phase determines values of optimal gas parameters. We discuss optimal parameters of gas and solid associated with minimum exergy consumption in drying proces. [ABSTRACT FROM AUTHOR]

This paper presents the modification of a harmony search algorithm (HS) for the capacitated vehicle routing problem (CVRP). The objective is to find a feasible set of vehicle routes that minimizes the total traveling distance and the number of vehicles used. The modified HS has two stages. First, the probabilistic Clarke-Wright savings algorithm was incorporated into harmony memory mechanism to improve its initial solution. Second, the roulette wheel selection procedure was employed into new harmony improvisation mechanism to improve its selection process. Computational results on the well-known CVRP benchmark problems show that the modified HS is competitive to the best existing algorithms. [ABSTRACT FROM AUTHOR]

Operation research is the representation of real-world systems by mathematical models together with the use of quantitative methods (algorithms) for solving such models, with a view to optimizing. As we know, C++ language is a middle level language and a computer program with this language is executed faster than application softwares of the operation research area. In this paper, a simple template program with simple C++ instructions is presented for simulating many types of optimization problems. This template is very easy to learn and understand for students or anyone who works in the operation research area. They can quickly and easily simulate many types of optimization problems with this template. [ABSTRACT FROM AUTHOR]

Compressed sensing (CS) is a powerful tool for signal measurement and processing, so it has caught much attention in many fields such as medical imaging and image restoration. In CS, we assume the latent signals, such as voices and images, are sparse; i.e. they have many zero components. On this assumption, we search the sparsest signal sufficing the linear measurement equalities. Usually instead of minimizing the number of nonzero components of signal, we minimize the l1 norm of the solution vector to satisfy the convex condition. Linear programming such as simplex method is often used for this l1 norm minimization. This paper proposes a fast algorithm for lp (00.95 norm minimization is 6.47 times faster than l1 simplex method. [ABSTRACT FROM AUTHOR]

This paper proposes a traffic engineering model to provide a better quality of service for VoIP in Wireless Mesh Networks (WMNs). We have developed an efficient algorithm in order to find the optimal path by combining the search for feasible routes with an optimization model to enhance the performance of VoIP over WMNs. Our goal of the joint optimization and the computation of feasible route is to minimize the network cost. The selection path use the independent set which are widely used in graph coloring problem to minimize interference. The idea is to build the independent set for the node Source (S) and Destination (D); also we make an intersection between those sets. Moreover, we formulate an optimization model which determines the optimal set of these criteria: hop count, link criticality and load balancing and we present initial performance results. [ABSTRACT FROM AUTHOR]

Car weight reduction is becoming more and more important for every kind of vehicle: minor mass implies, in fact, minor consumption, makes easier to fulfill homologation rules and assures a better handling behavior. Despite that, several vehicle missions have always been solved by adding more mass, e.g. NVH. In this paper, a methodology to optimize the stiffness distribution is proposed in order to obtain better vibrational performances without increasing the mass. At first, the problem has been solved for a simple beam using finite element and optimization algorithms. At a second stage, the optimal moment of inertia distribution found has been applied to a chassis thanks to a topometry optimization. Finally, the improvement in NVH performances has been verified comparing the inertances of the optimized model with those of the non-optimized one. [ABSTRACT FROM AUTHOR]