ParallelGlobal with Low Thread Interactions

Global is an optimization algorithm conceived in the ’80s. Since then several papers discussed improvements of the algorithm, but adapting it to a multi-thread execution environment is only a recent branch of development [1]. Our previous work focused on parallel implementation on a single machine but sometimes the use of distributed systems is inevitable. In this paper we introduce a new version of Global which is the first step towards a fully distributed algorithm. While the proposed implementation still works on a single machine, it is easy to see how gossip based information sharing can be built into and be utilized by the algorithm. We show that ParallelGlobal is a feasible way to implement Global on a distributed system. However, further improvements must be made to solve real world problems with the algorithm

Metamaterial properties of Babinet complementary complex structures

Single and multiple layers of sub-wavelength periodic Babinet complementary patterns composed of rounded nano-object miniarrays were investigated. In case of illumination with linearly and circularly polarized light the azimuthal orientation and handedness (in)dependence of (cross-polarized) copolarized transmitted signal components was proven for all types of patterns. Considerable (weak) asymmetric transmission was demonstrated in extended bands exclusively for both types of copolarized (cross-polarized) signals transmitted through single layer of convex miniarrays. Three-dimensional structures constructed with convex–concave–convex complex pattern-layers resulted in a negative index at the visible region boundary both for linearly and circularly polarized light illuminations. This is because dipolar modes on the convex nano-objects are synchronized with co-existent reversal dipoles on the concave nano-objects via interlayer coupling. Although during linearly polarized light illumination, the interlayer interaction decouples the localized and propagating modes excitable on the concave pattern in the 90° azimuthal orientation, the synchronization via tilted-rotating nanoring dipoles is almost perfect in the 0° azimuthal orientation. For circularly polarized light illumination, both the dispersion maps and the negative index phenomena synthesize the characteristics of the two orthogonal linearly polarized light illuminations. Important aspect is the appearance of a small/intermediate (large) time-averaged amplitude magnetic dipole due to the tilted (twisted) electric dipole on the concave nanoring, which less/more quickly turns (continuously rotates) with large/intermediate (small) out-of-plane tilting, when illumination is realized with linearly polarized light in the 90°/0° azimuthal orientation (with circularly polarized light). The location of the negative index can be predicted based on the copolarized transmittance signals computed for circularly polarized light illumination by using the linear base representation of Jones transmission matrix elements

Effects of Pooling in ParallelGlobal with Low Thread Interactions

The first step toward a new version of Global is discussed. It is a fully distributed algorithm. While the proposed implementation runs on a single machine, gossip based information sharing can be built into and be utilized by the algorithm. ParallelGlobal shows a feasible way to implement Global on a distributed system. Further improvements must be made to solve big real world problems with the algorithm

When to sell the ill cow?

In Hungary hundreds of thousands of cows produce milk for us. A common disease of them is mastitis that influences their productivity and profitability substantially. The usual practice is to decide on a rule of thumb basis whether the ill cow should be kept or sold. E.g. they are kept till the fifth mastitis case occurs. The present study investigates this problem from a mathematical modelling point of view. The relative amount of the possible lost profit is in the order of magnitude of 10s of percentages, which is quite large, especially regarding the profitability outlooks of the dairy branch. The problem lies in the personal relationship of the farmers to the cows, and in the complexity of the estimation of the uncertain future scenarios. We present a model that is based on collected historical data on the distribution of several model parameters such as the length of the illness, the amount of medicine needed, the number of inseminations required to get into the next lactation cycle etc. The applied methodology is microsimulation (i.e. we simulate all possible events one-by-one) and stochastic optimization. Our typical result is a suggested decision on the basis of the expected value of the profit/loss for the given animal. We report on the first results that confirm our research expectations in terms of improvement of the business decision. The ongoing research will focus on a recommendation system type data mining technology that can utilize the local specialties of the actual dairy farm in question, and to validate the additional advantage involved in it