Entropy2016, 18(7), 239; doi:10.3390/e18070239 (registering DOI) - published 24 June 2016 Show/Hide Abstract
Abstract: The minimum error entropy (MEE) algorithm is known to be superior in signal processing applications under impulsive noise. In this paper, based on the analysis of behavior of the optimum weight and the properties of robustness against impulsive noise, a normalized version of the MEE algorithm is proposed. The step size of the MEE algorithm is normalized with the power of input entropy that is estimated recursively for reducing its computational complexity. The proposed algorithm yields lower minimum MSE (mean squared error) and faster convergence speed simultaneously than the original MEE algorithm does in the equalization simulation. On the condition of the same convergence speed, its performance enhancement in steady state MSE is above 3 dB.
Entropy2016, 18(7), 238; doi:10.3390/e18070238 (registering DOI) - published 24 June 2016 Show/Hide Abstract
Abstract: This paper considers a special class of wiretap networks with a single source node and K sink nodes. The source message is encoded into a binary digital sequence of length N, divided into K subsequences, and sent to the K sink nodes respectively through noiseless channels. The legitimate receivers are able to obtain subsequences from arbitrary sink nodes. Meanwhile, there exist eavesdroppers who are able to observe subsequences from arbitrary sink nodes, where . The goal is to let the receivers be able to recover the source message with a vanishing decoding error probability, and keep the eavesdroppers ignorant about the source message. It is clear that the communication model is an extension of wiretap channel II. Secrecy capacity with respect to the strong secrecy criterion is established. In the proof of the direct part, a codebook is generated by a randomized scheme and partitioned by Csiszár’s almost independent coloring scheme. Unlike the linear network coding schemes, our coding scheme is working on the binary field and hence independent of the scale of the network.
Entropy2016, 18(7), 237; doi:10.3390/e18070237 (registering DOI) - published 24 June 2016 Show/Hide Abstract
Abstract: In manufacturing, thermal spray technology encompasses a group of coating processes that provide functional surfaces to improve the performance of the components and protect them from corrosion, wear, heat and other failings. Many types and forms of feedstock can be thermal sprayed, and each requires different process conditions and life cycle preparations. The required thermal energy is generated by a chemical (combustion) or electrical (plasma/or arc) energy source. Due to high inefficiencies associated with energy and material consumption in this process, a comprehensive resources used analysis for a sustainable improvement has always been promising. This study aims to identify and compare the influence of using different forms of feedstock (powder, suspension) as well as energy sources (combustion, plasma) on efficiency and effectiveness of energy conversion and resources consumption for different thermal spray processes based on energy and exergy analysis. Exergy destruction ratio and effectiveness efficiency are used to evaluate the energy conversion efficiency. The degree of perfection and degree of energy ratio are applied to account for the intensity of resources consumption (energy or material) in thermal spray processes. It is indicated that high velocity suspension flame spray has the lowest effectiveness efficiency and the highest exergy destruction compared to other thermal spray processes. For resource accounting purposes, in general, suspension thermal spray showed the lower degree of perfection and accordingly the higher inefficiency of resources used compared to powder thermal spray.
Entropy2016, 18(6), 234; doi:10.3390/e18060234 - published 22 June 2016 Show/Hide Abstract
Abstract: We study continuous countably-piecewise monotone interval maps and formulate conditions under which these are conjugate to maps of constant slope, particularly when this slope is given by the topological entropy of the map. We confine our investigation to the Markov case and phrase our conditions in the terminology of the Vere-Jones classification of infinite matrices.
Entropy2016, 18(6), 235; doi:10.3390/e18060235 - published 22 June 2016 Show/Hide Abstract
Abstract: Automatically extracting quantities and generating final answers for numerical attributes is very useful in many occasions, including question answering, image processing, human-computer interaction, etc. A common approach is to learn linguistics templates or wrappers and employ some algorithm or model to generate a final answer. However, building linguistics templates or wrappers is a tough task for builders. In addition, linguistics templates or wrappers are domain-dependent. To make the builder escape from building linguistics templates or wrappers, we propose a new approach to final answer generation based on Predicates-Units Table (PUT), a mini domain-independent knowledge base. It is deserved to point out that, in the following cases, quantities are not represented well. Quantities are absent of units. Quantities are perhaps wrong for a given question. Even if all of them are represented well, their units are perhaps inconsistent. These cases have a strong impact on final answer solving. One thousand nine hundred twenty-six real queries are employed to test the proposed method, and the experimental results show that the average correctness ratio of our approach is 87.1%.