Robot Task Allocation Using Signal Propagation Model

AbstractThe problem of Multi-Robot Task Allocation has received significant attention over last years. The solutions with decentralized decision making have proven better durability than those using centralized planning. In this paper a method which does not use any explicit communication is presented. It is especially suitable for very high dynamics of tasks priorities, when other methods must often perform time-consuming replanning. The method uses a simple model of signal emission and propagation in the environment. Simulation experiments are provided to demonstrate usability and interesting features of the method

Application of computational intelligence methods for the automated identification of paper-ink samples based on LIBS

Laser-induced breakdown spectroscopy (LIBS) is an important analysis technique with applications in many industrial branches and fields of scientific research. Nowadays, the advantages of LIBS are impaired by the main drawback in the interpretation of obtained spectra and identification of observed spectral lines. This procedure is highly time-consuming since it is essentially based on the comparison of lines present in the spectrum with the literature database. This paper proposes the use of various computational intelligence methods to develop a reliable and fast classification of quasi-destructively acquired LIBS spectra into a set of predefined classes. We focus on a specific problem of classification of paper-ink samples into 30 separate, predefined classes. For each of 30 classes (10 pens of each of 5 ink types combined with 10 sheets of 5 paper types plus empty pages), 100 LIBS spectra are collected. Four variants of preprocessing, seven classifiers (decision trees, random forest, k-nearest neighbor, support vector machine, probabilistic neural network, multi-layer perceptron, and generalized regression neural network), 5-fold stratified cross-validation, and a test on an independent set (for methods evaluation) scenarios are employed. Our developed system yielded an accuracy of 99.08%, obtained using the random forest classifier. Our results clearly demonstrates that machine learning methods can be used to identify the paper-ink samples based on LIBS reliably at a faster rate

Experimental verification of Hyper-V performance isolation level

The need for cost optimization in a broad sense constitutes the basis of operation of every enterprise. In the case of IT structure, which is present in almost every field of activity these days, one of the most commonly applied technologies leading to good cost-to-profit adjustment is virtualization. It consists in locating several operational systems with IT systems on a single server. In order for such optimization to be carried out correctly it has to be strictly controlled by means of allocating access to resources, which is known as performance isolation. Modern virtualizers allow to set up this allocation in quantitative terms (the number of processors, size of RAM, or disc space). It appears, however, that in qualitative terms (processor's time, RAM or hard disc bandwidth) the actual allocation of resources does not always correspond with this configuration. This paper provides an experimental presentation of the achievable level of performance isolation of the Hyper-V virtualizer

Współpraca jako rezultat mutacji i dziedziczenia w grach typu PD/PG

Podejście w grach ewolucyjnych, takich jak Dylemat więźnia, jest oparte przede wszystkim na spójnej strategii. W prezentowanym artykule zaproponowane zostało podejście, w którym współpraca dwóch więźniów może wynikać z mutacji oraz dziedziczenia. System ten ma charakter dylematu społecznego, w którym możliwe jest ustawienie przez każdego z agentów pożądanej dla niego liczby uczestników gry. Ponadto zostały zdefiniowane dwa podstawowe mechanizmy: wahania, które w wyniku mutacji prowadzi do współpracy, a także doboru naturalnego, który ma tendencję do promowania oszustów, w związku z czym zakłóca proces współpracy. W symulacjach numerycznych zostało wykazane, że wzajemne oddziaływanie między dwoma mechanizmami prowadzi do równowagi, a niecelowe strategie są konieczne do nawiązania i utrzymania współpracy między agentami. Tak więc, zaczynając od populacji nie współpracujących agentów, w wyniku procesu ewolucji, może skończyć się na populacji złożonej ze współpracujących grup ze średniej wielkości grupami określonymi przez stopień wahania oraz funkcję spłacającą. Artykuł dokładnie wyjaśnia wyniki numerycznych testów.The approach of evolutionary games like prisoner’s dilemma, among others, is based on a consistent strategy. We propose an experimentally verified system where cooperation can arise out of two simple factors: mutation and inheritance. This system has a social dilemma property and allows each agent to set its own desired number of participants. There are two essential mechanisms: fluctuation through which mutation leads to cooperation, and natural selection which tends to promote cheaters and therefore disrupts the cooperation. It is shown in numerical simulations that the interplay between both mechanisms leads to an equilibrium and that no intentional strategies are necessary to establish and sustain cooperation. Thus, starting from a population of non-cooperating agents, natural evolution can end with a population composed of cooperating groups with the mean group size determined by the fluctuation rate and the pay-off function. A thorough analytical explanation of numerical results is provided

Dynamika dystrybucji współautorów

W niniejszym artykule, na podstawie bazy artykułów naukowych, opisano ilościowy efekt wzrostu współpracy uczonych, która objawia się zmianami cech rozkładu liczby współautorów artykułu w czasie. Rozkład liczby współautorów artykułu dostępnego w bazie danych zmienia się w czasie z maksimum dla jednego autora do maksimum kilku autorów. Do wyjaśnienia dynamiki zmian rozkładu liczby współautorów zaproponowano model dylematu społecznego. Spośród trzech została wybrana jedna strategia współpracy odnosząca największe sukcesy.In the present paper, the case of a database of scientific articles is described. There can be observed the quantitative effects of the increasing strength of cooperation between scholars. It is manifested in time-related features changes of the numbers distribution of a single co-authors’ article. The distribution of the number of co-authors of an article recorded in the database evolves with time from a profile with no more than one author to a profile with several authors. A social dilemma model is proposed to explain the dynamics of changes in the distribution of the number of co-authors. The most successful strategy of the three considered alternative strategies of cooperation is selected

Influence of Methacrylate and Vinyl Monomers on Radical Bulk Photopolymerization Process and Properties of Epoxy-Acrylate Structural Adhesives

In this paper, epoxy-acrylate structural adhesives tapes (SATs) were obtained from Bisphenol A-based liquid epoxy resin and epoxy acrylic resins (EARs). A new method of EARs preparation, i.e., the free radical bulk photopolymerization process (FRBP), was studied in detail. The influence of methacrylic monomers (methyl methacrylate, ethyl methacrylate, butyl methacrylate, lauryl methacrylate, (2-acetoacetoxy)ethyl methacrylate) and vinyl monomers (N-vinylpyrrolidone and styrene) on the FRBP process of base monomers (i.e., butyl acrylate, glycidyl methacrylate and 2-hydroxyethyl acrylate) was investigated. The kinetics of photopolymerization process was monitored by photo-differential scanning calorimetry method. The properties of the obtained EARs (viscosity and average molecular weights), as well as monomers conversion using 1H NMR, were determined. It was revealed that styrene significantly decreases the photopolymerization rate and increases the final monomers conversion (+27%). However, the resulting tetrapolymers BA-co-GMA-co-HEA-co-STY have low molecular weights and low polydispersity (2.2). Methacrylate monomers with shorter aliphatic chains (4) also decrease the rate of photopolymerization due to the length of the aliphatic chain increasing. Surprisingly, the best results of adhesion to steel and shear strength were obtained for SAT based on epoxy acrylate resin with styrene (11 N/25 mm and 20.8 MPa, respectively). However, the thermomechanical properties of SAT with styrene were weaker than those with methacrylates

The Dynamics of the Distribution of co-authors

In the present paper, the case of a database of scientific articles is described. There can be observed the quantitative effects of the increasing strength of cooperation between scholars. It is manifested in time-related features changes of the numbers distribution of a single co-authors’ article. The distribution of the number of co-authors of an article recorded in the database evolves with time from a profile with no more than one author to a profile with several authors. A social dilemma model is proposed to explain the dynamics of changes in the distribution of the number of co-authors. The most successful strategy of the three considered alternative strategies of cooperation is selected

Emergence of cooperation as a result of mutation and inheritance in PD/PG-like game

The approach of evolutionary games like prisoner’s dilemma, among others, is based on a consistent strategy. We propose an experimentally verified system where cooperation can arise out of two simple factors: mutation and inheritance. This system has a social dilemma property and allows each agent to set its own desired number of participants. There are two essential mechanisms: fluctuation through which mutation leads to cooperation, and natural selection which tends to promote cheaters and therefore disrupts the cooperation. It is shown in numerical simulations that the interplay between both mechanisms leads to an equilibrium and that no intentional strategies are necessary to establish and sustain cooperation. Thus, starting from a population of non-cooperating agents, natural evolution can end with a population composed of cooperating groups with the mean group size determined by the fluctuation rate and the pay-off function. A thorough analytical explanation of numerical results is provided

Hand Body Language Gesture Recognition Based on Signals From Specialized Glove and Machine Learning Algorithms

The man-machine interface (MMI) is one of the most exciting areas of contemporary research. To make the MMI as convenient for a human as possible, it is desirable that efficient algorithms for recognizing body language are developed. This paper presents a system for quick and effective recognition of gestures of hand body language, based on data from a specialized glove equipped with ten sensors. In the experiment, 10 people performed 22 hand body language gestures. Each of the 22 gestures was executed 10 times. Collected data were preprocessed in multiple ways and three machine learning algorithms were designed based on classifiers (probabilistic neural network, support vector machine, and k-nearest neighbors algorithm) trained and tested by a tenfold cross-validation technique. The best designed classifiers gained effectiveness of gesture recognition at κ = 98.24% with a very short time of testing, below 1 ms. The experiments confirm that efficient and quick recognition of hand body language is possible