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Search results for: TREE METRICS
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Novel Polyurethanes as Antifouling Paint Matrices
PublicationThe new poly(ester-ether urethane)s (PEEUR) were prepared in two stage synthesis from formerly obtained oligo(alkylene ester-ether)diols (OAEE) and 4,4‘-diphenylmethane diisocyanate (MDI). PEEUR samples were subjected to crosslinking with styrene in the presence of radical polymerization initiators: methyl ethyl ketone peroxide (MEKPO) or cobalt 2-ethyl cyclohexanoate (EtHCo). Crosslinked PEEUR were characterized by their physicochemical...
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Mobbing as a problem in management ethics
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Lower bound on the weakly connected domination number of a tree
PublicationPraca dotyczy dolnego ograniczenia liczby dominowania słabo spójnego w drzewach (ograniczenie ze względu na ilość wierzchołków i ilość wierzchołków końcowych w drzewie).
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Lower bound on the distance k-domination number of a tree
PublicationW artykule przedstawiono dolne ograniczenie na liczbę k-dominowania w drzewach oraz scharakteryzowano wszystkie grafy ekstremalne.
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MINERAL CONTENT OF TREE SAP FROM THE SUBCARPATHIAN REGION
Publicationbut also as medicinal substance in folk medicine. Traditionally, it was used to treat various conditions, mostly anaemia and chronic fatigue. This study has been designed to establish the content of metallic elements (sodium, potassium, calcium, magnesium, zinc and copper) in sap collected from eight different species (silver birch, downy birch, hornbeam, Norway maple, boxelder maple, black walnut, black alder and white willow)...
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Atmospheric deposition in coniferous and deciduous tree stands in Poland
PublicationThe objective of this study was to assess the transformation of precipitation in terms of quantity and chemical composition following contact with the crown layer in tree stands with varied species composition, to investigate the effect of four predominant forest-forming species (pine, spruce, beech, and oak) on the amount and composition of precipitation reaching forest soils, and to determine the sources of pollution in atmospheric...
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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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Spectroscopic verification of ionic matrices for MALDI analysis
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Cholesky factorization of matrices in parallel and ranking of graphs.
PublicationUporządkowane kolorowanie znajduje zastosowanie przy równoległej faktoryzacji macierzy metodą Cholesky'ego. Praca zawiera opis tego zastosowania. Podano także algorytmy optymalnego uporządkowanego kolorowania krawędzi pewnych klas grafów: grafów pełnych dwudzielnych oraz powstałych z pełnych dwudzielnych przez usunięcie O(log n) krawędzi.
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Estimators of covariance matrices in Msplit(q) estimation
PublicationThis paper proposes methods for the determination of covariance matrices of Msplit(q) estimators. The solutions presented here allow Msplit(q) estimation to be supplemented by the operations from the domain of accuracy analysis (especially that concerning estimators of parameters). Theoretical forms of covariance matrices of Msplit(q) estimators were established using the empirical influence functions and the equivalent covariance...
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Comparing Phylogenetic Trees by Matching Nodes Using the Transfer Distance Between Partitions
PublicationAbility to quantify dissimilarity of different phylogenetic trees describing the relationship between the same group of taxa is required in various types of phylogenetic studies. For example, such metrics are used to assess the quality of phylogeny construction methods, to define optimization criteria in supertree building algorithms, or to find horizontal gene transfer (HGT) events. Among the set of metrics described so far in...
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An Algorithm for Listing All Minimal 2-Dominating Sets of a Tree
PublicationWe provide an algorithm for listing all minimal 2-dominating sets of a tree of order n in time O(1.3248n) . This implies that every tree has at most 1.3248 n minimal 2-dominating sets. We also show that this bound is tigh.
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An upper bound for the double outer-independent domination number of a tree
PublicationA vertex of a graph is said to dominate itself and all of its neighbors. A double outer-independent dominating set of a graph G is a set D of vertices of G such that every vertex of G is dominated by at least two vertices of D, and the set V(G)\D is independent. The double outer-independent domination number of a graph G, denoted by γ_d^{oi}(G), is the minimum cardinality of a double outer-independent dominating set of G. We prove...
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An algorithm for listing all minimal double dominating sets of a tree
PublicationWe provide an algorithm for listing all minimal double dominating sets of a tree of order $n$ in time $\mathcal{O}(1.3248^n)$. This implies that every tree has at most $1.3248^n$ minimal double dominating sets. We also show that this bound is tight.
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An Alternative Proof of a Lower Bound on the 2-Domination Number of a Tree
PublicationA 2-dominating set of a graph G is a set D of vertices of G such that every vertex not in D has a at least two neighbors in D. The 2-domination number of a graph G, denoted by gamma_2(G), is the minimum cardinality of a 2-dominating set of G. Fink and Jacobson [n-domination in graphs, Graph theory with applications to algorithms and computer science, Wiley, New York, 1985, 283-300] established the following lower bound on the 2-domination...
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A lower bound on the total outer-independent domination number of a tree
PublicationA total outer-independent dominating set of a graph G is a set D of vertices of G such that every vertex of G has a neighbor in D, and the set V(G)D is independent. The total outer-independent domination number of a graph G, denoted by gamma_t^{oi}(G), is the minimum cardinality of a total outer-independent dominating set of G. We prove that for every nontrivial tree T of order n with l leaves we have gamma_t^{oi}(T) >= (2n-2l+2)/3,...
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An upper bound on the 2-outer-independent domination number of a tree
PublicationA 2-outer-independent dominating set of a graph G is a set D of vertices of G such that every vertex of V(G)D has a at least two neighbors in D, and the set V(G)D is independent. The 2-outer-independent domination number of a graph G, denoted by gamma_2^{oi}(G), is the minimum cardinality of a 2-outer-independent dominating set of G. We prove that for every nontrivial tree T of order n with l leaves we have gamma_2^{oi}(T) <= (n+l)/2,...
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An upper bound on the total outer-independent domination number of a tree
PublicationA total outer-independent dominating set of a graph G=(V(G),E(G)) is a set D of vertices of G such that every vertex of G has a neighbor in D, and the set V(G)D is independent. The total outer-independent domination number of a graph G, denoted by gamma_t^{oi}(G), is the minimum cardinality of a total outer-independent dominating set of G. We prove that for every tree T of order n >= 4, with l leaves and s support vertices we have...
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A lower bound on the double outer-independent domination number of a tree
PublicationA vertex of a graph is said to dominate itself and all of its neighbors. A double outer-independent dominating set of a graph G is a set D of vertices of G such that every vertex of G is dominated by at least two vertices of D, and the set V(G)D is independent. The double outer-independent domination number of a graph G, denoted by gamma_d^{oi}(G), is the minimum cardinality of a double outer-independent dominating set of G. We...
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Hybridized PWM Strategy for Three- and Multiphase Three-Level NPC Inverters
PublicationA simple hybridized pulsewidth modulation (PWM) algorithm for three- and multiphase three-level neutral point clamped (NPC) inverters is proposed. The proposed solution is based on classical space vector PWM (SVPWM) algorithms for two-level inverters but can also be based on sinusoidal PWM with min–max injection. An additional level of output voltage is obtained by modifying the resulting switching patterns taking into account...
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Water clusters in liquid organic matrices of different polarity
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Determination of pesticide residues in food matrices using the QuEChERSmethodology
PublicationOznaczanie pozostałości pestycydów w próbkach żywności jest ogromnym wyzwaniem głównie z powodu dużych ilości substancji przeszkadzających, które podlegają ekstrakcji razem z analitami i najczęściej wywierają negatywny wpływ na tok analizy. Z drugiej strony, zapewnienie "bezpieczeństwa żywności" wymaga monitorowania w niej pozostałości pestycydów. W artykule przedstawiono nowe podejście do oznaczania pozostałości pestycydów w próbkach...
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A method for the analysis of methylmercury and total Hg in fungal matrices
PublicationThe aim of the study was to develop an efficient method for the determination of monomethyl-mercury (MeHg) and total mercury (THg) content in materials such as fungal sporocarps and sclerotia. Certified Reference Materials (CRMs) with the assigned values of MeHg and THg as well as the control materials (dried mushrooms) with known content of THg were evaluated for method validation. Recovery of MeHg from reference materials was...
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Paired bondage in trees
PublicationW pracy zdefiniowano pojęcie liczby zniewolenia parami jako moc najmniejszego zbioru krawędzi, którego usunięcie z grafu spowoduje wzrost liczby dominowania parami. W szczególności scharakteryzowane są wszystkie drzewa, w których liczba zniewolenia wynosi 0, czyli takie, w których usunięcie dowolnego podzbioru krawędzi nie zwiększy liczby dominowania parami.
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Preserving Trees in Automata
PublicationWe present a method to store additional information in a minimal automaton so that it is possible to compute a corresponding tree node number for a state. The number can then be used to retrieve additional information. The method works for minimal (and any other) deterministic acyclic finite state automata (DFAs). We also show how to compute the inverse mapping.
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On the partition dimension of trees
PublicationGiven an ordered partition Π={P1,P2,…,Pt} of the vertex set V of a connected graph G=(V,E), the partition representation of a vertex v∈V with respect to the partition Π is the vector r(v|Π)=(d(v,P1),d(v,P2),…,d(v,Pt)), where d(v,Pi) represents the distance between the vertex vv and the set Pi. A partition Π of V is a resolving partition of G if different vertices of G have different partition representations, i.e., for every...
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Isocyanate-Free Polyurethanes
PublicationIsocyanate-free polyurethanes (also called non-isocyanate polyurethanes, or NIPUs) are alternatives to the conventional (commercially used) polyurethanes synthesized using di- or polyisocyanates, polyols, and chain extenders with low molecular weight. The major routes of NIPUs’ synthesis involve polyaddition of cyclic carbonates and di- or polyamines, polycondensation of carbamates, and diols. The most important intermediates are...
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Perfect hashing with pseudo-minimal bottom-up deterministic tree automata
PublicationWe describe a technique that maps unranked trees to their hash codes using a bottom-up deterministic tree automaton (DTA). In contrast to techniques implemented with minimal tree automata, our procedure builds a pseudo-minimal DTA. Pseudo-minimal automata are larger than the minimal ones but in turn the mapping can be arbitrary, so it can be determined prior to the automaton construction. We also provide procedures to build incrementally...
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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.
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Empirical analysis of tree-based classification models for customer churn prediction
PublicationCustomer churn is a vital and reoccurring problem facing most business industries, particularly the telecommunications industry. Considering the fierce competition among telecommunications firms and the high expenses of attracting and gaining new subscribers, keeping existing loyal subscribers becomes crucial. Early prediction of disgruntled subscribers can assist telecommunications firms in identifying the reasons for churn and...
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Critical Case Stochastic Phylogenetic Tree Model via the Laplace Transform
PublicationBirth–and–death models are now a common mathematical tool to describe branching patterns observed in real–world phylogenetic trees. Liggett and Schinazi (2009) is one such example. The authors propose a simple birth–and–death model that is compatible with phylogenetic trees of both influenza and HIV, depending on the birth rate parameter. An interesting special case of this model is the critical case where the birth rate equals the...
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A city is not a tree: a multi-city study on street network and urban life
PublicationChristopher Alexander, a British-American scholar, differentiated an old (natural) city from a new (planned) one by structure. The former resembles a “semilattice”, or a complex system encompassing many interconnected sub-systems. The latter is shaped in a graph-theoretical “tree”, which lacks the structural complexity as its sub-systems are compartmentalized into a single hierarchy. This structural distinction explains why, or...
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A Strategy to Locate Fixed Points and Global Perturbations of ODE’s: Mixing Topology with Metric Conditions
PublicationIn this paper we discuss a topological treatment for the planar system z' = f (t, z) + g(t, z) where f and g are T -periodic in time and g(t, z) is bounded. Namely, we study the effect of g(t, z) in two different frameworks: isochronous centers and time periodic systems having subharmonics. The main tool employed in the proofs consists of a topological strategy to locate fixed points in the class of orientation preserving embedding...
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Determination of POPs in environmental matrices – proficiency tests for Polish laboratories
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Determination of POPs in environmental matrices - proficiency tests for Polish laboratories
PublicationKatedra Chemii Analitycznej Wydziału Chemicznego PG we współpracy ze Stowarzyszeniem RefMat oraz firmą LGC Promochem Sp. z o.o. prowadzi od 2003 roku wieloletni projekt badań biegłości laboratoriów. Celem badań jest określenie biegłości laboratoriów w zakresie oznaczania związków organicznych (anality z grupy PCB, WWA, pestycydy) w próbkach środowiskowych. W ramach projektu przeprowadzono dotychczas trzy badania biegłości dotyczące...
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Modern techniques of extraction of organic analytes from environmental matrices.
PublicationW pracy przedstawiono usystematyzowane informacje dotyczące dostępnych jak i nowych technik izolacji i wzbogacania analitów organicznych przed etapem oznaczeń końcowych.
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Structural studies of bismuth nanocrystals embedded in SiO2 or GeO2 matrices.
PublicationW wyniku wygrzewania w atmosferze wodoru szkieł bizmutowych i germanowych otrzymano warstwę nanogranul bizmutu w otoczeniu amorficznej matrycy oraz powierzchniową warstwę bizmutowych granul. Grubość i struktura tak otrzymanych warstw silnie zależy od czasu i temperatury redukcji.
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Absorbing Boundary Conditions Derived Based on Pauli Matrices Algebra
PublicationIn this letter, we demonstrate that a set of absorbing boundary conditions (ABCs) for numerical simulations of waves, proposed originally by Engquist and Majda and later generalized by Trefethen and Halpern, can alternatively be derived with the use of Pauli matrices algebra. Hence a novel approach to the derivation of one-way wave equations in electromagnetics is proposed. That is, the classical wave equation can be factorized...
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Generation of large finite-element matrices on multiple graphics processors
PublicationThis paper presents techniques for generating very large finite-element matrices on a multicore workstation equipped with several graphics processing units (GPUs). To overcome the low memory size limitation of the GPUs, and at the same time to accelerate the generation process, we propose to generate the large sparse linear systems arising in finite-element analysis in an iterative manner on several GPUs and to use the graphics...
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Analysis of compressive forces in CFGFT cylindrical pillars and their coatings using laboratory tests and metric spaces
PublicationThe article discusses compressive forces tests in composite-concrete pillars with the use of laboratory active experiment including the factors and properties of materials which have a significant impact on the test results and their repeatability. A polymer composite based on glass fiber reinforced resin with different fiber beam angles (20, 55 and 85) was used as a buffer/coat of the pole. Due to the problems with direct comparison...
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Minimum vertex ranking spanning tree problem for chordal and proper interval graphs
PublicationW pracy rozważamy problem szukania, dla danego grafu prostego, drzewa spinającego, którego uporządkowana liczba chromatyczna jest minimalna. K.~Miyata i inni dowiedli w [Np-hardness proof and an approximation algorithm for the minimum vertex ranking spanning tree problem,Discrete Appl. Math. 154 (2006) 2402-2410], że odpowiedni problem decyzyjny jest NP-trudny już w przypadku pytania o istnienie uporządkowanego 4-pokolorowania....
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Multidimensional Feature Selection and Interaction Mining with Decision Tree Based Ensemble Methods
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INDIVIDUAL TREE DETECTION FROM UAV LIDAR DATA IN A MIXED SPECIES WOODLAND
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Fault Tree Analysis and Failure Diagnosis of Marine Diesel Engine Turbocharger System
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Tree-based homogeneous ensemble model with feature selection for diabetic retinopathy prediction
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Construction of a picewise-linear classifier by applaing discriminant analysis to decision tree induction
PublicationArtykuł prezentuje metodę konstrukcji drzew decyzyjnych. W odróżnieniu od większości popularnych algorytmów, które wybierają pojedyncze cechy do budowy reguł decyzyjnych w węzłach drzewa, ta metoda łączy wszystkie cechy. Używa ona wieloklasowego kryterium Fishera do wydzielenia nowych cech, które są liniowa kombinacją cech pierwotnych. Takie drzewa mogą aproksymować złożone regiony decyzyjne używając mniejszej liczby węzłów w porównaniu...
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The complexity of list ranking of trees
PublicationUporządkowane kolorowanie grafu polega na takim etykietowaniu jego wierzchołków, aby każda ścieżka łącząca dwa wierzchołki o tym samym kolorze zawierała wierzchołek o kolorze wyższym. Jeśli każdy wierzchołek posiada dodatkowo listę dozwolonych dla niego etykiet, to mówimy wówczas o uporządkowanym listowym kolorowaniu wierzchołków. W pracy wskazano szereg klas grafów, dla których problem jest trudny: pełne drzewa binarne, drzewa...
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Connected searching of weighted trees
PublicationW artykule rozważamy problem spójnego przeszukiwania drzew obciążonych. Autorzy w [L. Barriere i inni, Capture of an intruder by mobile agents, SPAA'02 (2002) 200-209] twierdzą, że istnieje wielomianowy algorytm dla problemu obliczania optymalnej strategii przeszukiwania obciążonego drzewa. W niniejszej pracy pokazano, że problem ten jest obliczeniowo trudny nawet dla wierzchołkowo-obciążonych drzew (wagi krawędzi równe 1) oraz...
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Collision-free network exploration
PublicationMobile agents start at different nodes of an n-node network. The agents synchronously move along the network edges in a collision-free way, i.e., in no round two agents may occupy the same node. An agent has no knowledge of the number and initial positions of other agents. We are looking for the shortest time required to reach a configuration in which each agent has visited all nodes and returned to its starting location. In...
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Three-fast-searchable graphs
PublicationIn the edge searching problem, searchers move from vertex to vertex in a graph to capture an invisible, fast intruder that may occupy either vertices or edges. Fast searching is a monotonic internal model in which, at every move, a new edge of the graph G must be guaranteed to be free of the intruder. That is, once all searchers are placed the graph G is cleared in exactly |E(G)| moves. Such a restriction obviously necessitates...