We consider dynamic selection problems, where a decision maker repeatedly selects a set of items from a larger collection of available items. A classic example is the dynamic assortment problem, where a retailer chooses items to offer for sale subject to a display space constraint. The retailer may adjust the chosen assortment over time in response to the observed demand. These dynamic selectio...

An improved Lagrangian relaxation (LR) solution to the thermal unit commitment problem (UCP) is proposed in this paper. The algorithm is characterized by: (1) a new Matlab function to determine the optimal path of the dual problem, (2) new initialization procedure of Lagrangian multipliers, based on both unit and time interval classification, (3) a flexible adjustment of Lagrangian multipliers,...

objective: the present study compares the efficacy of two most commonly used biofeedback relaxation techniques in the treatment of generalized anxiety disorder. method: 45 individuals with generalized anxiety disorder were randomly assigned to three groups (n=15): group i received electromyographic biofeedback relaxation training, group ii received alpha-electroencephalographic biofeedback rela...

the complete 3d nonlinear dynamic problem of extensible, flexible risers conveying fluid is considered. for describing the dynamics of the system, the newtonian derivation procedure is followed. the velocity field inside the pipe formulated using hydrostatic and bernoulli equations. the hydrodynamic effects of external fluids are taken into consideration through the nonlinear drag forces in var...

although many scholars have proposed all kinds of key successful factors (ksfs) for erp activity to smoothly enhance the implementation of erp, the ksfs are based too much on concept and protocol cannot help an enterprise to achieve this objective. therefore, this research through qualitative interview method, integrating the ksfs and dynamic capability to set up a model so as to exhibit the ki...

in this study, dynamic buckling of embedded laminated nanocomposite plates is investigated. the plates are reinforced with single-walled carbon nanotubes (swcnts) where to obtain the equivalent material properties of them, mori-tanaka model is applied. based on the sinusoidal shear deformation theory (ssdt), the motion equations are derived using energy method and hamilton's principal. the...

transfer matrix method (tmm) has been applied to analyze characteristics of semiconductor laser optical amplifiers. the input signal is sinusoidal modulating wave and we do not assume the modulating bias signal as well. we have shown that the distoration arises from gain modulation at low modulation frequencies, but in microwave modulation frequencies, the gain takes an average value and the re...

A subgrid turbulence model for the lattice Boltzmann method is proposed for high Reynolds number fluid flow applications. The method, based on the standard Smagorinsky subgrid model and a single-time relaxation lattice Boltzmann method, incorporates the advantages of the lattice Boltzmann method for handling arbitrary boundaries and is easily implemented on parallel machines. The method is appl...