Lifetime modelling with aid of a modified complementary weibull distribution

The complementary Weibull distribution may serve as a lifetime model for various applications. A modification of this distribution is introduced. Its purpose is to enable the calculation of the MTBF integral, which does not exist for the regular complementary Weibull function. An efficient quadrature technique is provided. Its utility is validated through some examples.     

Composition and in-vitro digestibility of carbohydrates of wheat plants harvested at bloom and soft-dough stages

Wheat plants (Triticum aestivum) were harvested at the bloom and soft-dough stages, separated into leaves + sheaths, stems and spikes, and the effect of stage of maturity on neutral detergent fibre (NDF) composition and degradability was studied, the accumulation of starch in the spikes compensated for the decrease in the degradability of NDF polysaccharides so that the in-vitro digestibility of the organic matter (OM) was not changed between the bloom and soft-dough stages. Minor compositional changes occurred in the NDF of the various botanical fractions which can hardly explain the drop in NDF degradability with maturity. There was a decline in the ratio of hemicellulose to lignin, and the changes in NDF-monosaccharide degradability were probably related to the extension of covalent bonding between those matrix components during maturation. Irrespective of botanical fraction and maturity stage, NDF xylose was less digestible than NDF glucose. Between bloom and soft-dough stages there was an increase of 36% in the yield of digestible OM.     

Autonomous agents and human cultures in the trust–revenge game

Autonomous agents developed by experts are embedded with the capability to interact well with people from different cultures. When designing expert agents intended to interact with autonomous agents developed by non-game theory agents (NGTE), it is beneficial to obtain insights on the behavior of these NGTE agents. Is the behavior of these NGTE agents similar to human behavior from different cultures? This is an important question as such a quality would allow an expert agent interacting with NGTE agents to model them using the same methods that are used to model humans from different cultures. To study this point, we evaluated NGTE agents behavior using a game called the Trust–Revenge game, which is known in social science for capturing different human tendencies. The Trust–Revenge game has a unique subgame-perfect equilibrium strategy profile, however, very rarely do people follow it. We compared the behavior of autonomous agents to the actions of several human demographic groups—one of which is similar to the designers of the autonomous agents. We claim that autonomous agents are similar to human players from various cultures. This enables the use of approaches, developed for handling cultural diversity among humans, to be applied for interaction with NGTE agents. This paper also analyzes additional aspects of autonomous agents behavior and whether composing autonomous agents affects human behavior.     

Information Dynamics

Though we have access to a wealth of information, the main issue is always how to process the available information. How to make sense of all we observe and know. Just like the English alphabet: we know there are 26 letters but unless we put these letters together in a meaningful way, they convey no information. There are infinitely many ways of putting these letters together. Only a small number of those make sense. Only some of those convey exactly what we wish to convey though the message may be interpreted differently by different individuals. That same issue comes up with information: how can we process the information we have? How can we infer and reason under conditions of incomplete observed information? In his seminal book on the philosophy of information, Floridi (2011a) raises a number of open questions. I discuss here one of these questions. That question is how to process information. To do so, I take the more realistic view that information is always limited, incomplete and possibly noisy. I define types of information, relate it to Floridi’s definitions and discuss a basic formulation for processing information under a unified framework. I relate it to some of the basic concepts discussed in the book.     

Enhancing GPU parallelism in nature-inspired algorithms

We present GPU implementations of two different nature-inspired optimization methods for well-known optimization problems. Ant Colony Optimization (ACO) is a two-stage population-based method modelled on the foraging behaviour of ants, while P systems provide a high-level computational modelling framework that combines the structure and dynamic aspects of biological systems (in particular, their parallel and non-deterministic nature). Our methods focus on exploiting data parallelism and memory hierarchy to obtain GPU factor gains surpassing 20x for any of the two stages of the ACO algorithm, and 16x for P systems when compared to sequential versions running on a single-threaded high-end CPU. Additionally, we compare performance between GPU generations to validate hardware enhancements introduced by Nvidia’s Fermi architecture.     

Computer simulation of an FMS conveyor

In this paper, we present a method of computer simulation of the control and scheduling of FMS (flexible manufacturing system) conveyors. First we explain the process of simulating conveyours, pallets, sensors, identifying elements and motors, which are the most common components of FMS transportation systems. Afterwards we explain the way to simulate and drive a real FMS transportation system.     

Influence of dietary protein degradability and energy concentration on growth of heifers and steers and intraruminal protein metabolism

Two studies with 4-mo old Holstein steers and heifers and one abomasal digesta collection study were used to determine the influence of altering the dietary energy content and crude protein escape on growth, intraruminal protein metabolism, and site of digestion of dry matter, starch, cellulose, hemicellulose, and protein. Dietary energy concentration was increased by tallow, and rumen protein escape was increased by dehydrated alfalfa and distillers dried grains with solubles substituted for soybean meal. Tallow appeared to depress intake and gain, but gain was increased by protein escape from the rumen. Total and particulate digesta crude protein reaching the abomasum was increased by protein escape; however, percentage crude protein digested was decreased in these treatments due to increased acid detergent insoluble nitrogen. Decreasing crude protein solubility decreased ruminoreticular digestion of dry matter, cellulose, hemicellulose, and starch; however, lower intestinal starch digestion compensated for decreased ruminoreticular digestion. In a third study, with growing steers and heifers, corn gluten meal provided the escape protein and soybean meal the degradable protein. Total and average daily gain were greater for the corn gluten meal diet, but intake was not influenced by energy concentration or protein escape.     

Implementation of an Associative Flow Rule Including Hydrostatic Stress Effects into the High Strain Rate Deformation Analysis of Polymer Matrix Composites

A previously developed analytical formulation has been modified in order to more accurately account for the effects of hydrostatic stresses on the nonlinear, strain rate dependent deformation of polymer matrix composites. State variable constitutive equations originally developed for metals have been modified in order to model the nonlinear, strain rate dependent deformation of polymeric materials. To account for the effects of hydrostatic stresses, which are significant in polymers, the classical J2 plasticity theory definitions of effective stress and effective inelastic strain, along with the equations used to compute the components of the inelastic strain rate tensor, are appropriately modified. To verify the revised formulation, the shear and tensile deformation of a representative polymer are computed across a wide range of strain rates. Results computed using the developed constitutive equations correlate well with experimental data. The polymer constitutive equations are implemented within a strength of materials based micromechanics method to predict the nonlinear, strain rate dependent deformation of polymer matrix composites. The composite mechanics are verified by analyzing the deformation of a representative polymer matrix composite for several fiber orientation angles across a variety of strain rates. The computed values compare well to experimentally obtained results.