Filters
total: 8603
-
Catalog
displaying 1000 best results Help
Search results for: approximation algorithm, graph coloring, incompatible job, polynomial algorithm, scheduling, uniform machine, unit-time job
-
An approximation algorithm for maximum P3-packing in subcubic graphs
PublicationW pracy podano algorytm 4/3-przyliżony dla trudnego obliczeniowo problemu umieszczania wierzchołkowo rozłącznych dwukrawędziowych ścieżek w grafach o stopniu maksymalnym 3 i stopniu minimalnym 2. Poprawiono tym samym wcześniejsze wyniki dla grafów kubicznych (A. Kelmans, D. Mubayi, Journal of Graph Theory 45, 2004).
-
Edge-coloring of 3-uniform hypergraphs
PublicationWe consider edge-colorings of 3-uniform hypergraphs which is a natural generalization of the problem of edge-colorings of graphs. Various classes of hypergraphs are discussed and we make some initial steps to establish the border between polynomial and NP-complete cases. Unfortunately, the problem appears to be computationally difficult even for relatively simple classes of hypergraphs.
-
ANYTIME POLYNOMIAL HEURISTIC ALGORITHM FOR PARTITIONING GROUPS OF DATA WITH PRESERVING CLASS PROPORTIONS FOR CROSS-VALIDATION
PublicationThe article describes a problem of splitting data for k-fold cross-validation, where class proportions must be preserved, with additional constraint that data is divided into groups that cannot be split into different cross-validation sets. This problem often occurs in e.g. medical data processing, where data samples from one patient must be included in the same cross-validation set. As this problem is NP-complete, a heuristic...
-
A Method of Real-Time Non-uniform Speech Stretching
PublicationDeveloped method of real-time non-uniform speech stretching is presented.The proposed solution is based on the well-known SOLA algorithm(Synchronous Overlap and Add). Non-uniform time-scale modification isachieved by the adjustment of time scaling factor values in accordance with thesignal content. Dependently on the speech unit (vowels/consonants), instantaneousrate of speech (ROS), and speech signal presence, values of the scalingfactor...
-
A non-uniform real-time speech time-scale stretching method
PublicationAn algorithm for non-uniform real-time speech stretching is presented. It provides a combination of typical SOLA algorithm (Synchronous Overlap and Add ) with the vowels, consonants and silence detectors. Based on the information about the content and the estimated value of the rate of speech (ROS), the algorithm adapts the scaling factor value. The ability of real-time speech stretching and the resultant quality of voice were...
-
The effect of job-related stress on psychological well-being = Wpływ stresu zawodowego na dobrostan psychiczny
PublicationThe aim of the investigation was to evaluate the effect of job stress factors on psychological well-being of firemen. Goldberg's GHQ-12 for well-being evaluation, the Perceived Job Stress Questionnaire by Dudek et al. for job stress assessment, and indicator of participation in traumatic events were used. 19% of the firemen were qualified to the group with increased risk of mental disorders. Occupational stress had a strong impact...
-
Eqiuitable coloring of corona products of cubic graphs is harder than ordinary coloring
PublicationA graph is equitably k-colorable if its vertices can be partitioned into k independent sets in such a way that the number of vertices in any two sets differ by at most one. The smallest k for which such a coloring exists is known as the equitable chromatic number of G. In this paper the problem of determinig the equitable coloring number for coronas of cubic graphs is studied. Although the problem of ordinary coloring of coronas...
-
Scheduling with precedence constraints: mixed graph coloring in series-parallel graphs.
PublicationW pracy rozważono problem kolorowania grafów mieszanych, opisujący zagadnienie szeregowania zadań, w którym zależności czasowe zadań mają charakter częściowego porządku lub wzajemnego wykluczania. Dla przypadku, w którym graf zależności jest szeregowo-równoległy, podano algorytm rozwiązujący problem optymalnie w czasie $O(n^3.376 * log n)$.
-
Dynamic F-free Coloring of Graphs
PublicationA problem of graph F-free coloring consists in partitioning the vertex set of a graph such that none of the resulting sets induces a graph containing a fixed graph F as an induced subgraph. In this paper we consider dynamic F-free coloring in which, similarly as in online coloring, the graph to be colored is not known in advance; it is gradually revealed to the coloring algorithm that has to color each vertex upon request as well...
-
Job Demands, Engagement, and Turnover Intentions in Polish Nurses: The Role of Work-Family Interface
PublicationBackground: Poland has lower ratios of employed registered nurses per 1,000 inhabitants than the EU average. Polish nurses work under miserable conditions without assisting personnel, and they reconcile their professional demands with responsibilities for their families; 96% of them are women. Rationale/Aims: This study uses Hobfoll’s conservation of resources (CORs) theory to explain the role of various resources in the improvement...
-
Psychometric properties of the polish version of the job-related affective well-being scale
PublicationObjectives: The aim of this study was to verify psychometric properties of the Polish version of the Job-related Affective Well-being Scale (JAWS). Specifically, theoretical 4-factor structure (based on the dimensions of pleasure and arousal) and reliability of the original – 20-item JAWS (van Katwyk et al., 2000) and the shortened – 12-item (Schaufeli and Van Rhenen, 2006) versions were tested. Material and Methods: Two independent...
-
Statistically efficient smoothing algorithm for time-varying frequency estimation
PublicationThe problem of extraction/elimination of a nonstationary sinusoidal signal from noisy measurements is considered. This problem is usually solved using adaptive notch filtering (ANF) algorithms. It is shown that the accuracy of frequency estimates can be significantly increased if the results obtained from ANF are backward-time filtered by an appropriately designed lowpass filter. The resulting adaptive notch smoothing (ANS) algorithm...
-
A polynomial algorithm for finding T-span of generalized cacti
Publication -
A polynomial algorithm for finding T-span of generalized cacti.
PublicationW pracy opisano wielomianowy algorytm wyznaczający optymalne T-pokolorowania dla uogólnionych kaktusów.
-
Self-stabilizing algorithm for edge-coloring of graphs
PublicationReferat ten poświęcony jest kolorowaniu grafów w modelu rozproszonym.Podano samostabilizujący się algorytm kolorowania krawędzi grafu wraz z dowodem poprawności oraz oszacowaniem jego czasu działania.
-
The smallest hard-to-color graph for algorithm DSATUR
Publication -
The smallest hard-to-color graph for the SL algorithm
Publication -
The Mediation Function of Job Satisfaction's between Organizational Culture Dimensions and Knowledge Sharing
PublicationIt is commonly acknowledged that organizational culture is a valuable element of intellectual capital and as a hidden source of competitive advantage can considerably affect the achieving of strategic business goals. The axiological dimension of organizational culture is mostly identified with a set of shared assumptions and values, while work practices mainly define its behavioral dimension. Both these dimensions influence, among...
-
Equitable 4-coloring of cacti and edge-cacti in polynomial time
PublicationRozważono problem wyznaczania sprawiedliwej liczby chromatycznej kaktusów i drzew wielokątowych bez trójkątów i krawędzi wiszących. Podano wielomianowy algorytm wyznaczający pokolorowanie optymalne, oparty na paradygmacie programowania dynamicznego. Tym samym znaleziona została kolejna klasa grafów planarnych, dla której kolorowanie sprawiedliwe jawi się jako zagadnienie obliczeniowo łatwe.
-
On-line P-coloring of graphs
PublicationFor a given induced hereditary property P, a P-coloring of a graph G is an assignment of one color to each vertex such that the subgraphs induced by each of the color classes have property P. We consider the effectiveness of on-line P-coloring algorithms and give the generalizations and extensions of selected results known for on-line proper coloring algorithms. We prove a linear lower bound for the performance guarantee function...
-
The work-family interface: Job demands, work engagement and turnover intentions of Polish nurses
PublicationA conflict between one's professional life and one's family life may lead to lower well-being both at work and home. Most nurses are women who have traditionally reconciled their professional life with family life. One aim of this study was to examine the relationships between the work-family conflict (WFC),the family-work conflict (FWC), and the perception of job demands (quantitative workload and interpersonal conflicts at work)....
-
Equitable coloring of hypergraphs
PublicationA hypergraph is equitablyk-colorable if its vertices can be partitioned into k sets/colorclasses in such a way that monochromatic edges are avoided and the number of verticesin any two color classes differs by at most one. We prove that the problem of equitable 2-coloring of hypergraphs is NP-complete even for 3-uniform hyperstars. Finally, we apply the method of dynamic programming for designing a polynomial-time algorithm to...
-
Neural modelling of dynamic systems with time delays based on an adjusted NEAT algorithm
PublicationA problem related to the development of an algorithm designed to find an architecture of artificial neural network used for black-box modelling of dynamic systems with time delays has been addressed in this paper. The proposed algorithm is based on a well-known NeuroEvolution of Augmenting Topologies (NEAT) algorithm. The NEAT algorithm has been adjusted by allowing additional connections within an artificial neural network and...
-
Equitable coloring of corona multiproducts of graphs
PublicationWe give some results regarding the equitable chromatic number for l-corona product of two graphs: G and H, where G is an equitably 3- or 4-colorable graph and H is an r-partite graph, a cycle or a complete graph. Our proofs lead to polynomial algorithms for equitable coloring of such graph products provided that there is given an equitable coloring of G.
-
A polynomial algorithm for solving a general max‐min fairness problem
Publication -
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...
-
Performance of Watermarking-based DTD Algorithm Under Time-varying Echo Path Conditions
PublicationA novel double-talk detection (DTD) algorithm based on techniques similar to those used for audio signal watermarking was introduced by the authors. The application of the described DTD algorithm within acoustic echo cancellation system is presented. The problem of DTD robustness to time-varying conditions of acoustic echo path is discussed and explanation as to why such conditions occur in practical situations is provided. The...
-
Robustness analysis of watermarking-based dtd algorithm under time-variable echo conditions
PublicationA novel double-talk detection (DTD) algorithm based on techniques similar to those used for audio signal watermarking was introduced by the authors. The application of the described DTD algorithm within acoustic echo cancellation system is presented. The problem of DTD robustness to time-varying conditions of acoustic echo path is discussed and explanation as to why such conditions occur in practical situations is provided. The...
-
Toward an understanding of occupational burnout among employees with autism – the Job Demands‑Resources theory perspective
PublicationThis article aims to gain insight into the phenomenon of occupational burnout among employees with autism based on the theoretical framework of the Job Demands-Resources theory and the literature on employees with autism in the workplace. Firstly, we argue that although the resources and demands of the neurotypical and neurodivergent employees might be different, the theoretical mechanism of occupational burnout formation remains...
-
Uniform expansion estimates in the quadratic map as a function of the partition size, using Johnson’s algorithm
Open Research DataThis dataset contains selected results of numerical computations described in the paper "Quantitative hyperbolicity estimates in one-dimensional dynamics" by S. Day, H. Kokubu, S. Luzzatto, K. Mischaikow, H. Oka, P. Pilarczyk, published in Nonlinearity, Vol. 21, No. 9 (2008), 1967-1987, doi: 10.1088/0951-7715/21/9/002.
-
Eventual Convergence of the Reputation-Based Algorithm in IoT Sensor Networks
PublicationUncertainty in dense heterogeneous IoT sensor networks can be decreased by applying reputation-inspired algorithms, such as the EWMA (Exponentially Weighted Moving Average) algorithm, which is widely used in social networks. Despite its popularity, the eventual convergence of this algorithm for the purpose of IoT networks has not been widely studied, and results of simulations are often taken in lieu of the more rigorous proof....
-
Gdańsk University of Technology graduates’ job position – years 2013-2018
Open Research DataThe dataset includes data from the survey on the Gdańsk University of Technology graduates from years 2013-2018 on their current job position. The survey was conducted in the period from 2015 to 2020, two years after the respondents obtained graduate status. The research sample included 11190 respondents. To summarizing, the Gdańsk University of Technology...
-
Genetic Algorithm Approach for Gains Selection of Induction Machine Extended Speed Observer
PublicationThe subject of this paper is gains selection of an extended induction machine speed observer. A high number of gains makes manual gains selection difficult and due to nonlinear equations of the observer, well-known methods of gains selection for linear systems cannot be applied. A method based on genetic algorithms has been proposed instead. Such an approach requires multiple fitness function calls; therefore, using a quality index...
-
A self-stabilizing algorithm for finding a spanning tree in a polynomial number of moves
PublicationW pracy rozważa się rozproszony model obliczeń, w którym struktura systemu jest reprezentowana przez graf bezpośrednich połączeń komunikacyjnych. W tym modelu podajemy nowy samostabilizujący algorytm znajdowania drzewa spinającego. Zgodnie z naszą wiedzą jest to pierwszy algorytm dla tego problemu z gwarantowaną wielomianową liczbą ruchów.
-
Finding small-width connected path decompositions in polynomial time
PublicationA connected path decomposition of a simple graph $G$ is a path decomposition $(X_1,\ldots,X_l)$ such that the subgraph of $G$ induced by $X_1\cup\cdots\cup X_i$ is connected for each $i\in\{1,\ldots,l\}$. The connected pathwidth of $G$ is then the minimum width over all connected path decompositions of $G$. We prove that for each fixed $k$, the connected pathwidth of any input graph can be computed in polynomial-time. This answers...
-
Photoplethysmographic Time-Domain Heart Rate Measurement Algorithm for Resource-Constrained Wearable Devices and its Implementation
PublicationThis paper presents an algorithm for the measurement of the human heart rate, using photoplethysmography (PPG), i.e., the detection of the light at the skin surface. The signal from the PPG sensor is processed in time-domain; the peaks in the preprocessed and conditioned PPG waveform are detected by using a peak detection algorithm to find the heart rate in real time. Apart from the PPG sensor, the accelerometer is also used to...
-
Performance comparison of new modified gradient algorithm and Foy algorithm for iterative position calculation
PublicationIn the paper a new position calculation algorithm is presented. It is proposed for indoor environments and is called modified gradient algorithm. This algorithm is compared with well-known Foy algorithm. The comparative analysis is based on real distance measurements conducted in indoor environment.
-
Uniform expansion estimates in the quadratic map as a function of the partition size, using the Floyd–Warshall algorithm
Open Research DataThis dataset contains selected results of numerical computations described in the paper "Quantitative hyperbolicity estimates in one-dimensional dynamics" by S. Day, H. Kokubu, S. Luzzatto, K. Mischaikow, H. Oka, P. Pilarczyk, published in Nonlinearity, Vol. 21, No. 9 (2008), 1967-1987, doi: 10.1088/0951-7715/21/9/002.
-
Performance Evaluation of the Parallel Codebook Algorithm for Background Subtraction in Video Stream
PublicationA background subtraction algorithm based on the codebook approach was implemented on a multi-core processor in a parallel form, using the OpenMP system. The aim of the experiments was to evaluate performance of the multithreaded algorithm in processing video streams recorded from monitoring cameras, depending on a number of computer cores used, method of task scheduling, image resolution and degree of image content variability....
-
Optimal backbone coloring of split graphs with matching backbones
PublicationFor a graph G with a given subgraph H, the backbone coloring is defined as the mapping c: V(G) -> N+ such that |c(u)-c(v)| >= 2 for each edge uv \in E(H) and |c(u)-c(v)| >= 1 for each edge uv \in E(G). The backbone chromatic number BBC(G;H) is the smallest integer k such that there exists a backbone coloring with max c(V(G)) = k. In this paper, we present the algorithm for the backbone coloring of split graphs with matching backbone.
-
Chromatic cost coloring of weighted bipartite graphs
PublicationGiven a graph G and a sequence of color costs C, the Cost Coloring optimization problem consists in finding a coloring of G with the smallest total cost with respect to C. We present an analysis of this problem with respect to weighted bipartite graphs. We specify for which finite sequences of color costs the problem is NP-hard and we present an exact polynomial algorithm for the other finite sequences. These results are then extended...
-
A Fortran-95 algorithm to solve the three-dimensional Higgs boson equation in the de Sitter space-time
Open Research DataA numerically efficient finite-difference technique for the solution of a fractional extension of the Higgs boson equation in the de Sitter space-time is designed. The model under investigation is a multidimensional equation with Riesz fractional derivatives of orders in (0,1)U(1,2], which considers a generalized potential and a time-dependent diffusion...
-
Computational algorithm for the analysis of mechatronic systems with distributed parameter elements
PublicationThe paper presents a systematic computational package for analysis of complex systems composed of multiple lumped and distributed parameter subsystems. The algorithm is based on the transfer function method (DTFM). With this algorithm, a bond graph technique for the modelling is developed to simplify computations. Analysis of different systems requires only changing the inputs data in the form of the bond graph diagram
-
Data Reduction Algorithm for Machine Learning and Data Mining
Publication -
Graph security testing
PublicationSet S ⊂ V is called secure set iff ∀ X ⊂ S | N [ X ] ∩ S | ≥ | N ( X ) \ S | [3]. That means that every subset of a secure set has at least as many friends (neighbour vertices in S) as enemies (neighbour vertices outside S) and will be defended in case of attack. Problem of determining if given set is secure is co −NP -complete, there is no efficient algorithm solving it [3]. Property testers are algorithms that distinguish inputs...
-
Elgold partial: Job offers
Open Research DataThe dataset contains 34 English texts scrapped from the web portals offering job offers. In each text, the named entities are marked. Each name entity is linked to the corresponding Wikipedia if possible. All entities were manually verified by at least three people, which makes the dataset a high-quality gold standard for the evaluation of named entity...
-
On the Characteristic Graph of a Discrete Symmetric Channel
PublicationWe present some characterizations of characteristic graphs of row and/or column symmetric channels. We also give a polynomial-time algorithm that decides whether there exists a discrete symmetric channel whose characteristic graph is equal to a given input graph. In addition, we show several applications of our results.
-
Gender and Job Satisfaction of Information Technology Professionals in Poland
Publication -
Parallel scheduling by graph ranking
PublicationNr dokum.: 73017Praca dotyczy jednego z nieklasycznych modeli kolorowania grafów - uporządkowanego kolorowania. Celem było uzyskanie wyników, które mogo być wykorzystane w praktycznych zastosowaniach tego modelu, do których należą: równoległe przetwarzanie zapytań w relacyjnych bazach danych, równoległa faktoryzacja macierzy metodą Choleskiego, równoległa asemblacja produktu z jego części składowych. W pracy wskazano uogólnienia...
-
Partial dominated schedules and minimizing the total completion time of deteriorating jobs
PublicationA problem of scheduling deteriorating jobs on a single processor is considered. The processing time of a job is given by a function pi=ai+bisi, where si is the starting time of the job, ai>=0, bi>=0, for i=1,...,n. Jobs are non-preemptive and independent and there are neither ready times nor deadlines. The goal is to minimize the total weighted completion time. We show how to employ the concept of non-dominated schedules to construct...