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Extensions of Quasilinearization Method for Differential Equations with Integral Boundary Conditions
PublicationPraca dotyczy równań różniczkowych z warunkami brzegowymi typu całkowego. Podano warunki dostateczne na istnienie jedynego rozwiązania takiego zagadnienia i pokazano, że odpowiednio konstruowane ciągi monotoniczne są zbieżne do tego rozwiązania i jest to zbieżność kwadratowa. Te monotoniczne ciągi są przybliżonymi rozwiązaniami problemu wyjściowego i obustronnie szacują szukane rozwiązanie.
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Sustainable Waste Management for Implementation of a Circular Economy Model in a Port
PublicationThe manuscript presents the management of waste from marine vessels and cargo handling companies in a selected European Union port. The main objective of the paper is to analyse and evaluate the existing waste management model in the port of Szczecin in the context of circular economy. The expert research carried out is aimed, inter alia, at identifying which of the solutions currently in use need to be improved from an environmental...
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ARIMA vs LSTM on NASDAQ stock exchange data
PublicationThis study compares the results of two completely different models: statistical one (ARIMA) and deep learning one (LSTM) based on a chosen set of NASDAQ data. Both models are used to predict daily or monthly average prices of chosen companies listed on the NASDAQ stock exchange. Research shows which model performs better in terms of the chosen input data, parameters and number of features. The chosen models were compared using...
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Machine learning applied to acoustic-based road traffic monitoring
PublicationThe motivation behind this study lies in adapting acoustic noise monitoring systems for road traffic monitoring for driver’s safety. Such a system should recognize a vehicle type and weather-related pavement conditions based on the audio level measurement. The study presents the effectiveness of the selected machine learning algorithms in acoustic-based road traffic monitoring. Bases of the operation of the acoustic road traffic...
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Consensus models: Computational complexity aspects in modern approaches to the list coloring problem
PublicationArtykuł poświęcony jest nowym modelom konsensusowego kolorowania grafów. Artykuł zawiera omówienie trzech takich modeli, analizę ich złożoności obliczeniowej oraz wielomianowy algorytm dla częściowych k-drzew, dla tzw. modelu addytywnego.
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Connected searching of weighted trees
PublicationW pracy pokazano, że problem spójnego przeszukiwania drzew ważonych jest silnie NP-zupełny. Problem pozostaje trudnym dla drzew z jednym wierzchołkiem o stopniu większym niż 2. Ponadto, przedstawiony został wielomianowy optymalny algorytm dla klasy drzew z ograniczonym stopniem.
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Topology recognition and leader election in colored networks
PublicationTopology recognition and leader election are fundamental tasks in distributed computing in networks. The first of them requires each node to find a labeled isomorphic copy of the network, while the result of the second one consists in a single node adopting the label 1 (leader), with all other nodes adopting the label 0 and learning a path to the leader. We consider both these problems in networks whose nodes are equipped with...
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Designing Intelligent Factory: Conceptual Framework and Empirical Validation
PublicationThis paper presents a framework for monitoring, analysing and decision making for a smart manufacturing environment. We maintain that this approach could play a vital role in developing an architecture and implementation of Industry 4.0. The proposed model has features like experience based knowledge representation and semantic analysis of engineering objects and manufacturing process. It is also capable of continuous real time...
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Brushing with additional cleaning restrictions
PublicationIn graph cleaning problems, brushes clean a graph by traversing it subject to certain rules. We consider the process where at each time step, a vertex that has at least as many brushes as incident, contaminated edges, sends brushes down these edges to clean them. Various problems arise, such as determining the minimum number of brushes (called the brush number) that are required to clean the entire graph. Here, we study a new variant...
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VIBRATION DIAGNOSTICS OF FOOTBRIDGE WITH USE OF ROTATION SENSOR
PublicationThe benefits of the additional measurement of rotational degrees of free-dom on the performance of the vibration diagnosis of bridges are studied in this paper. The common vibrational diagnostics that uses translational degrees of freedom is extended by measurements of rotations. The study is curried out on a footbridge and the presence of damage as well as its location and size is determined with use of FEM updating procedure....
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Optimization model of agile team’s cohesion
PublicationTeam’s cohesion is one of the most important factors of IT project execution effectiveness. Optimization of team’s cohesion gives the possibility of reducing the risk of project failure. It also allows to increase the teamwork efficiency and thus optimize time of tasks execution, increase the guarantee of maintaining the scope of the project and the chance of achieving a given level of products quality. This article presents determination...
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Implementing Virtual Engineering Objects (VEO) with the Set of Experience Knowledge Structure (SOEKS)
PublicationThis paper illustrates the idea of Virtual Engineering Object (VEO) powered by Set of Experience Knowledge Structure (SOEKS) and Decisional DNA (DDNA). A VEO is the knowledge representation of an engineering object, having embodiment of all its associated knowledge and experience within it. Moreover, VEO is a specialization of Cyber-Physical System (CPS) in terms of that its extension in knowledge gathering and reuse, whereas CPS...
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Low-Cost EM-Simulation-Driven Multi-Objective Optimization of Antennas
PublicationA surrogate-based method for efficient multi-objective antenna optimization is presented. Our technique exploits response surface approximation (RSA) model constructed from sampled low-fidelity antenna model (here, obtained through coarse-discretization EM simulation). The RSA model enables fast determination of the best available trade-offs between conflicting design goals. A low-cost RSA model construction is possible through...
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Fast Low-fidelity Wing Aerodynamics Model for Surrogate-Based Shape Optimization
PublicationVariable-fidelity optimization (VFO) can be efficient in terms of the computational cost when compared with traditional approaches, such as gradient-based methods with adjoint sensitivity information. In variable-fidelity methods, the directoptimization of the expensive high-fidelity model is replaced by iterative re-optimization of a physics-based surrogate model, which is constructed from a corrected low-fidelity model. The success...
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Viability of decisional DNA in robotics
PublicationThe Decisional DNA is an artificial intelligence system that uses prior experiences to shape future decisions. Decisional DNA is written in the Set Of Experience Knowledge Structure (SOEKS) and is capable of capturing and reusing a broad range of data. Decisional DNA has been implemented in several fields including Alzheimer’s diagnosis, geothermal energy and smart TV. Decisional DNA is well suited to use in robotics due to the...
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The Hybrid Fuzzy - SOEKS Approach to the Polish Internet Mortgage Market
PublicationThe paper presents the hybrid fuzzy- SOEKS approach to the Polish Internet mortgage market, which is treated as an example of a fast changing market. Firstly, the market and market problems are described. Then, the first approach to the market problems is presented: the complete fuzzy model which was built basing on the rules. The fuzzy model is presented on one real data case. Next, the new approach, called Set of Experience Knowledge...
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The complexity of zero-visibility cops and robber
PublicationWe consider the zero-visibility cops & robber game restricted to trees. We produce a characterisation of trees of copnumber k and We consider the computational complexity of the zero-visibility Cops and Robber game. We present a heavily modified version of an already-existing algorithm that computes the zero-visibility copnumber of a tree in linear time and we show that the corresponding decision problem is NP-complete on a nontrivial...
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A highly-efficient technique for evaluating bond-orientational order parameters
PublicationWe propose a novel, highly-efficient approach for the evaluation of bond-orientational order parameters (BOPs). Our approach exploits the properties of spherical harmonics and Wigner 3jj-symbols to reduce the number of terms in the expressions for BOPs, and employs simultaneous interpolation of normalised associated Legendre polynomials and trigonometric functions to dramatically reduce the total number of arithmetic operations....
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On minimum cost edge searching
PublicationWe consider the problem of finding edge search strategies of minimum cost. The cost of a search strategy is the sum of searchers used in the clearing steps of the search. One of the natural questions is whether it is possible to find a search strategy that minimizes both the cost and the number of searchers used to clear a given graph G. We call such a strategy ideal. We prove, by an example, that ideal search strategies do not...
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Synchronous black hole search in directed graphs
PublicationThe paper considers a team of robots which has to explore a graph G, where some nodes can be harmful. Robots are initially located at the so-called home base node. The dangerous nodes are the so-called black hole nodes, and once a robot enters in one of them, it is destroyed. The goal is to find a strategy in order to explore G in such a way that minimum number of robots is wasted. The exploration ends if there is at least one...
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Smaller representation of finite state automata
PublicationThis paper is a follow-up to Jan Daciuk's experiments on space-efficient finite state automata representation that can be used directly for traversals in main memory (Daciuk, 2000)[4]. We investigate several techniques for reducing memory footprint of minimal automata, mainly exploiting the fact that transition labels and transition pointer offset values are not evenly distributed and so are suitable for compression. We achieve...
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An extended basis inexact shift–invert Lanczos for the efficient solution of large-scale generalized eigenproblems
PublicationThis paper proposes a technique, based on the Inexact Shift–Invert Lanczos (ISIL) method with Inexact Jacobi Orthogonal Component Correction (IJOCC) refinement, and a preconditioned conjugate-gradient (PCG) linear solver with multilevel preconditioner, for finding several eigenvalues for generalized symmetric eigenproblems. Several eigenvalues are found by constructing (with the ISIL process) an extended projection basis. Presented...
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The searchlight problem for road networks
PublicationWe consider the problem of searching for a mobile intruder hiding in a road network given as the union of two or more lines, or two or more line segments, in the plane. Some of the intersections of the road network are occupied by stationary guards equipped with a number of searchlights, each of which can emit a single ray of light in any direction along the lines (or line segments) it is on. The goal is to detect the intruder,...
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Distinguishing views in symmetric networks: A tight lower bound
PublicationThe view of a node in a port-labeled network is an infinite tree encoding all walks in the network originating from this node. We prove that for any integers n ≥ D ≥ 1, there exists a port-labeled network with at most n nodes and diameter at most D which contains a pair of nodes whose (infinite) views are different, but whose views truncated to depth Omega( D log(n/ D )) are identical.
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Virtual Engineering Object / Virtual Engineering Process: A specialized form of Cyber Physical System for Industrie 4.0
PublicationThis paper reviews the theories, parallels and variances between Virtual Engineering Object (VEO) / Virtual Engineering Process (VEP) and Cyber Physical System (CPS). VEO and VEP is an experience based knowledge representation of engineering objects and processes respectively. Cyber–physical systems (CPSs) are the next generation of engineered systems in which computing, communication, and control technologies are tightly integrated....
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Rendezvous of heterogeneous mobile agents in edge-weighted networks
PublicationWe introduce a variant of the deterministic rendezvous problem for a pair of heterogeneous agents operating in an undirected graph, which differ in the time they require to traverse particular edges of the graph. Each agent knows the complete topology of the graph and the initial positions of both agents. The agent also knows its own traversal times for all of the edges of the graph, but is unaware of the corresponding traversal...
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Multi-GPU UNRES for scalable coarse-grained simulations of very large protein systems
PublicationGraphical Processor Units (GPUs) are nowadays widely used in all-atom molecular simulations because of the advantage of efficient partitioning of atom pairs between the kernels to compute the contributions to energy and forces, thus enabling the treatment of very large systems. Extension of time- and size-scale of computations is also sought through the development of coarse-grained (CG) models, in which atoms are merged into extended...
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YADE - An extensible framework for the interactive simulation of multiscale, multiphase, and multiphysics particulate systems
PublicationThis contribution presents the key elements of YADE, an extensible open-source framework for dynamic simulations. During the past 19 years, YADE has evolved from "Yet Another Dynamic Engine"' to a versatile multiscale and multiphysics solver, counting a large, active, and growing community of users and developers. The computationally intense parts of the source code are written in C++, using flexible object models that allow for...
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Very accurate time propagation of coupled Schrödinger equations for femto- and attosecond physics and chemistry, with C++ source code
PublicationIn this article, I present a very fast and high-precision (up to 33 decimal places) C++ implementation of the semi-global time propagation algorithm for a system of coupled Schrödinger equations with a time-dependent Hamiltonian. It can be used to describe time-dependent processes in molecular systems after excitation by femto- and attosecond laser pulses. It also works with an arbitrary user supplied Hamiltonian and can be used...
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The complexity of bicriteria tree-depth
PublicationThe tree-depth problem can be seen as finding an elimination tree of minimum height for a given input graph G. We introduce a bicriteria generalization in which additionally the width of the elimination tree needs to be bounded by some input integer b. We are interested in the case when G is the line graph of a tree, proving that the problem is NP-hard and obtaining a polynomial-time additive 2b-approximation algorithm. This particular...
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Airfoil Design Under Uncertainty Using Non-Intrusive Polynomial Chaos Theory and Utility Functions
PublicationFast and accurate airfoil design under uncertainty using non-intrusive polynomial chaos (NIPC) expansions and utility functions is proposed. The NIPC expansions provide a means to efficiently and accurately compute statistical information for a given set of input variables with associated probability distribution. Utility functions provide a way to rigorously formulate the design problem. In this work, these two methods are integrated...
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Pareto Ranking Bisection Algorithm for EM-Driven Multi-Objective Design of Antennas in Highly-Dimensional Parameter Spaces
PublicationA deterministic technique for fast surrogate-assisted multi-objective design optimization of antennas in highly-dimensional parameters spaces has been discussed. In this two-stage approach, the initial approximation of the Pareto set representing the best compromise between conflicting objectives is obtained using a bisection algorithm which finds new Pareto-optimal designs by dividing the line segments interconnecting previously...
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Approximate search strategies for weighted trees
PublicationW pracy podajemy 3-przybliżony algorytm dla problemu spójnego przeszukiwania drzew ważonych.
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Three levels of fail-safe mode in MPI I/O NVRAM distributed cache
PublicationThe paper presents architecture and design of three versions for fail-safe data storage in a distributed cache using NVRAM in cluster nodes. In the first one, cache consistency is assured through additional buffering write requests. The second one is based on additional write log managers running on different nodes. The third one benefits from synchronization with a Parallel File System (PFS) for saving data into a new file which...
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Tools, Methods and Services Enhancing the Usage of the Kepler-based Scientific Workflow Framework
PublicationScientific workflow systems are designed to compose and execute either a series of computational or data manipulation steps, or workflows in a scientific application. They are usually a part of a larger eScience environment. The usage of workflow systems, however very beneficial, is mostly not irrelevant for scientists. There are many requirements for additional functionalities around scientific workflows systems that need to be...
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Modeling and Simulation for Exploring Power/Time Trade-off of Parallel Deep Neural Network Training
PublicationIn the paper we tackle bi-objective execution time and power consumption optimization problem concerning execution of parallel applications. We propose using a discrete-event simulation environment for exploring this power/time trade-off in the form of a Pareto front. The solution is verified by a case study based on a real deep neural network training application for automatic speech recognition. A simulation lasting over 2 hours...
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2-Coloring number revisited
Publication2-Coloring number is a parameter, which is often used in the literature to bound the game chromatic number and other related parameters. However, this parameter has not been precisely studied before. In this paper we aim to fill this gap. In particular we show that the approximation of the game chromatic number by the 2-coloring number can be very poor for many graphs. Additionally we prove that the 2-coloring number may grow...
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TISAX - optimization of IT risk management in the automotive industry
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ChatGPT - opportunities or threats in the educational process
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Building a cybersecurity culture of public administration system in Poland
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Gossiping by energy-constrained mobile agents in tree networks
PublicationEvery node of an edge-weighted tree network contains a data packet. At some nodes are placed mobile agents, each one possessing an amount of energy (not necessarily the same for all agents). While walking along the network, the agents spend the energy proportionally to the distance traveled and collect copies of the data packets present at the visited network nodes. An agent visiting a node deposits there copies of all currently...
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Agile Requirements Prioritization in Practice: Results of an Industrial Survey
PublicationAgile software development stresses the importance of providing the customer with a product of a maximized business value. To achieve that, requirements prioritization is used. Agile development methods like Scrum define guidelines for prioritization, however practitioners do not necessarily have to follow them. Our goal was to investigate the industry practice related to requirements prioritization process, including its timing,...
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Improving the Performance of Ontological Querying by using a Contextual Approach
PublicationIn the paper we present the results of experiment we performed to determine whether a contextual approach may be used to increase the performance of querying a knowledge base. For the experiments we have used a unique setting where we put much effort in developing a contextual and a non-contextual ontology which are as much close counterparts as possible. To achieve this we created a contextual version...
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Contextual ontology for tonality assessment
Publicationclassification tasks. The discussion focuses on two important research hypotheses: (1) whether it is possible to construct such an ontology from a corpus of textual document, and (2) whether it is possible and beneficial to use inferencing from this ontology to support the process of sentiment classification. To support the first hypothesis we present a method of extraction of hierarchy of contexts from a set of textual documents...
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Visual content representation and retrieval for Cognitive Cyber Physical Systems
PublicationCognitive Cyber Physical Systems have gained significant attention from academia and industry during the past few decade. One of the main reasons behind this interest is the potential of such technologies to revolutionize human life since they intend to work robustly under complex visual scenes, which environmental conditions may vary, adapting to a comprehensive range of unforeseen changes, and exhibiting prospective behavior...
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Smart Virtual Product Development (SVPD) to Enhance Product Manufacturing in Industry 4.0
PublicationThis paper presents a system capable of enhancing product development process for industrial manufactured products. This system is known as Smart Virtual Product Development (SVPD), and it helps in decision making by using explicit knowledge of formal decision events. It stores and reuses the past decisional events or sets of experiences related to different activities involved in industrial product development process i.e. product...
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Industry 4.0 Implementation Challenges in Manufacturing Industries: an Interpretive Structural Modelling Approach
PublicationFor the last few years, the fourth industrial revolution, known as Industry 4.0, has been a hot topic among academics. Industry 4.0 literature involves researches presenting studies related to its different aspects including challenges, opportunities, implementation and adoption. However, a detailed study of challenges and barriers towards the Industry 4.0 implementation in manufacturing industries is missing. Hence, this paper...
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Microscopic traffic simulation models for connected and automated vehicles (CAVs) – state-of-the-art
PublicationResearch on connected and automated vehicles (CAVs) has been gaining substantial momentum in recent years. However, thevast amount of literature sources results in a wide range of applied tools and datasets, assumed methodology to investigate thepotential impacts of future CAVs traffic, and, consequently, differences in the obtained findings. This limits the scope of theircomparability and applicability and calls for a proper standardization...
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Smart Virtual Product Development (SVPD) System to Support Product Inspection Planning in Industry 4.0
PublicationThis paper presents the idea of supporting product inspection planning process during the early stages of product life cycle for the experts working on product development. Aim of this research is to assist a collaborative product development process by using Smart Virtual Product Development (SVPD) system, which is based on Set of Experience Knowledge Structure (SOEKS) and Decisional DNA (DDNA). The proposed system is developed...
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Current trends in consumption of multimedia content using online streaming platforms: A user-centric survey
PublicationIn its early days, consumption of multimedia content was only possible at a stationary terminal device. The music player was located at home, and had to have a physical drive. Over the last decade, there has been an enormous increase in the number of online streaming platforms. These services enable users to consume rich multimedia content on various devices. Thanks to the widespread and availability of portable devices, any person...