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Search results for: DEGREE THEORY
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Modeling of Composite Shells in 6-Parameter Nonlinear Theory with Drilling Degree of Freedom
PublicationWithin the framework of a 6-parameter nonlinear shell theory, with strain measures of Cosserat type, constitutive relations are proposed for thin elastic composite shells. The material law is expressed in terms of five engineering constants of classical anisotropic continuum plus an additional parameter accounting for drilling stiffness. The theory allows for unlimited displacements and rotations. A number of examples are presented...
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Experimental evidence about misconception of Terzaghi's 1-D consolidation theory in terms of degree of consolidation
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Module structure in Conley theory with some applications
PublicationA multiplicative structure in the cohomological versjon of Conley index is described . In the case of equivariant flows we apply the normalization procedure known from equivariant degree theory and we propose a new continuation invariant. The theory is then applied to obtain a mountain pass type theorem. Another application is a result on multiple bifurcations for some elliptic PDE.
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Generalized Gradient Equivariant Multivalued Maps, Approximation and Degree
PublicationConsider the Euclidean space Rn with the orthogonal action of a compact Lie group G. We prove that a locally Lipschitz G-invariant mapping f from Rn to R can be uniformly approximated by G-invariant smooth mappings g in such a way that the gradient of g is a graph approximation of Clarke’s generalized gradient of f . This result enables a proper development of equivariant gradient degree theory for a class of set-valued gradient...
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Topological invariants for equivariant flows: Conley index and degree
PublicationAbout forty years have passed since Charles Conley defined the homotopy index. Thereby, he generalized the ideas that go back to the calculus of variations work of Marston Morse. Within this long time the Conley index has proved to be a valuable tool in nonlinear analysis and dynamical systems. A significant development of applied methods has been observed. Later, the index theory has evolved to cover such areas as discrete dynamical...
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Adolfo Poma
PeopleI am the group leader of the computational modelling of biomolecules divison at the institute of Fundamental Technological Research Polish Academy of Sciences in Poland. My group was hosted between 2021-2022 by International Centre for Research on Innovative Bio-based Materials (ICRI-BioM). In 2008, I got a Master degree in computational physics from the State University of Campinas, Brazil. Then I moved to Germany and under the...
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Degree of monopoly and market power vs. price flexibility in Polish economy: empirical analysis based on COICOP classification
PublicationResearch background: The issue of price flexibility is crucial in the economy both in the aspect of company theory and its macroeconomic consequences. In a number of publications, the sources of variable price flexibility are linked to the market power of enterprises as well as the market structure that has developed in a given branch. It is difficult to indicate empirical studies that would state clearly whether price flexibility...
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Geometrically nonlinear FEM analysis of FGM shells based on neutral physical surface approach in 6-parameter shell theory
PublicationThe paper presents the formulation of the elastic constitutive law for functionally graded materials (FGM) on the grounds of nonlinear 6-parameter shell theory with the 6th parameter being the drilling degree of freedom. The material law is derived by through-the-thickness integration of the Cosserat plane stress equations. The constitutive equations are formulated with respect to the neutral physical surface. The influence of...
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Theory vs. practice. Searching for a path of practical education
PublicationThe introduction of a three-tier model of higher education (the Bologna model) has led to considerable changes in the 1st- and 2nd-tier technical courses at universities. At present, a student with a bachelor’s degree can be employed in his / her profession after completing only 7 semesters of study. A search is under way for methods of combining theoretical knowledge taught at universities with practical knowledge gained afterwards....
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The Method of a Two-Level Text-Meaning Similarity Approximation of the Customers’ Opinions
PublicationThe method of two-level text-meaning similarity approximation, consisting in the implementation of the classification of the stages of text opinions of customers and identifying their rank quality level was developed. Proposed and proved the significance of major hypotheses, put as the basis of the developed methodology, notably about the significance of suggestions about the existence of analogies between mathematical bases of...
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Examination of selected failure criteria with asymmetric shear stresses in the collapse analysis of laminated shells
PublicationThe paper is concerned with failure analysis of composite shells performed with the usage of the nonlinear 6‐parameter shell theory with drilling rotation degree of freedom. This special theory embodies naturally unlim-ited translations and rotations and is suitable for analysis of irregular shells for instance with various, partic-ularly orthogonal, intersections. The presence of the drilling rotation is inherently accompanied...
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Impact of the Manufacturing Sector on the Export Competitiveness of European Countries – a Spatial Panel Analysis
PublicationThe purpose of this paper is to determine how changes in the export competitiveness of the EU economy (measured by exports and net exports) depend on changes in the competitiveness of processing industries, on the basis of manufacturing data from 19 EU countries over years 1995-2009 and using a spatial panel data model. The determinants of export competitiveness are selected in the light of predictions from international trade...
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2-D constitutive equations for orthotropic Cosserat type laminated shells in finite element analysis
PublicationWe propose 2-D Cosserat type orthotropic constitutive equations for laminated shells for the purpose of initial failure estimation in a laminate layer. We use nonlinear 6-parameter shell theory with asymmetric membrane strain measures and Cosserat kinematics as the framework. This theory is specially dedicated to the analysis of irregular shells, inter alia, with orthogonal intersections, since it takes into account the drilling...
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Elastoplastic nonlinear FEM analysis of FGM shells of Cosserat type
PublicationThe paper is a continuation of [1] where the formulation of the elastic constitutive law for functionally graded materials (FGM) on the grounds of nonlinear 6-parameter shell theory with the 6th parameter (the drilling degree of freedom) was presented. Here the formulation is extended to the elasto-plastic range. The material law is based on Cosserat plasticity and employs the well-known Tamura-Tomota-Ozawa (TTO) [2] mixture...
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KONKURENCYJNOŚĆ SEKTORÓW PRZEMYSŁU PRZETWÓRCZEGO I ICH WPŁYW NA MIĘDZYNARODOWĄ KONKURENCYJNOŚĆ GOSPODARKI POLSKIEJ – ANALIZA PANELOWA
PublicationCelem rozdziału jest określenie, na bazie danych sektorowych i z wykorzystaniem modelu panelowego, w jakim stopniu zmiany międzynarodowej konkurencyjności gospodarki polskiej wynikają ze zmian w konkurencyjności sektorów przemysłu przetwórczego. Determinanty konkurencyjności sektorów przemysłu zostały wybrane w świetle dorobku teorii handlu zagranicznego, teorii wzrostu oraz teorii innowacji. W szczególności pragniemy zbadać, jak...
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Geminate-pair dissociation yield in systems with exponential energetic disorder — A Monte Carlo study
PublicationGeminate electron–hole recombination in systems with exponential energetic disorder is studied by Monte Carlo method. The field and temperature dependencies of geminate-pair dissociation probability are calculated. It is established that the dissociation yield of carrier pairs depends mainly on the extent of carrier thermalization, which influences the Einstein relationship. The approximate limiting temperature is given by Te =...
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Piotr Szczuko dr hab. inż.
PeoplePiotr Szczuko received his M.Sc. degree in 2002. His thesis was dedicated to examination of correlation phenomena between perception of sound and vision for surround sound and digital image. He finished Ph.D. studies in 2007 and one year later completed a dissertation "Application of Fuzzy Rules in Computer Character Animation" that received award of Prime Minister of Poland. His interests include: processing of audio and video, computer...
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Hydraulic valve design methodology for hydro turbine control system
PublicationThe control of the turbine and its equipment in a hydroelectric power plant requires the HPU (hydraulic power unit) to deliver large volumes of working fluid in a short time at specific optimum control parameters. The use of typical proportional flow control valves created by manufacturers of hydraulic components in low-pressure control systems is disadvantageous due to high pressure losses in the control chambers. This paper presents...
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Interference between Land and Sea Logistics Systems. Multifunctional Building System Design Towards Autonomous Integrated Transport Infrastructure
PublicationThe research is focused on developing design theory towards efficient multifunctional facilities for logistics supply chains in the contemporary urban city structures. The development of modern systems based on autonomous transport creates new conditions for their management and generates an emerging need to define dedicated functional service structures. An important element of consideration also taken into account is the scenario...
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Vegetable derived-oil facilitating carbon black migration from waste tire rubbers and its reinforcement effect
PublicationThree dimensional chemically cross-linked polymer networks present a great challenge for recycling and reutilization of waste tire rubber. In this work, the covalently cross-linked networks of ground tire rubber (GTR) were degraded heterogeneously under 150 °C due to the synergistic effects of the soybean oil and controlled oxidation. The degradation mechanism was discussed using Horikx theory and Fourier transformation infrared...
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Jolanta Łopatowska dr inż.
PeopleJolanta Łopatowska, assistant professor at the Department of Management Engineering and Quality at the Faculty of Management and Economics, is a graduate of the Faculty of Electronics at Gdańsk University of Technology and Institute of Organization and Design of Production Systems at Gdańsk University of Technology. She obtained Ph.D. degree in the discipline of Economic Science. Her scientific and research interests focus on organizationally...
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Paweł Szymon Dąbrowski dr inż.
PeopleDr. Eng. Paweł Szymon Dąbrowski studied geodesy and cartography at the University of Warmia and Mazury in Olsztyn from 2004-2009, where he obtained the title of Master of Science in Engineering. In the years 2009-2016, he worked as a land surveyor in Iława and Gdańsk. He gained professional experience during the construction of the Pomeranian Metropolitan Railway, which helped him obtain a national surveying license in 2015. In...
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Jerzy Konorski dr hab. inż.
PeopleJerzy Konorski received his M. Sc. degree in telecommunications from Gdansk University of Technology, Poland, and his Ph. D. degree in computer science from the Polish Academy of Sciences, Warsaw, Poland. In 2007, he defended his D. Sc. thesis at the Faculty of Electronics, Telecommunications and Informatics, Gdansk University of Technology. He has authored over 150 papers, led scientific projects funded by the European Union,...
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Piotr Bartłomiejczyk dr hab.
PeopleW roku 2014 zostałem zatrudniony w Katedrze Równań Różniczkowych i Zastosowań Matematyki na Wydziale Fizyki Technicznej i Matematyki Stosowanej Politechniki Gdańskiej. Zajmuję się badaniem niezmienników występujących w analizie nieliniowej. W roku 2000 uzyskałem stopień naukowy doktora w zakresie nauk matematycznych w Instytucie Matematycznym Polskiej Akademii Nauk w Warszawie. Uchwałą Rady Wydziału Matematyki, Fizyki i Informatyki...
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Exploiting multi-interface networks: Connectivity and Cheapest Paths
PublicationLet G = (V,E) be a graph which models a set of wireless devices (nodes V) that can communicate by means of multiple radio interfaces, according to proximity and common interfaces (edges E). The problem of switching on (activating) the minimum cost set of interfaces at the nodes in order to guarantee the coverage of G was recently studied. A connection is covered (activated) when the endpoints of the corresponding edge share at...
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Jan Kozicki dr hab. inż. arch.
PeopleIn year 2002 after obtaining master's degree in construction was employed on Faculty of Civil and Environmental Engineering. In 2004 obtained master's degree in architecture on Faculty of Architecture focusing on a research outpost on Mars. Defended PhD in year 2007 in the field of numerical modeling. In 2013 obtained Licentiate degree in theoretical physics on University of Gdańsk. In year 2014 obtained habilitation in technical...
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The Hopf type theorem for equivariant gradient local maps
PublicationWe construct a degree-type otopy invariant for equivariant gradient local maps in the case of a real finite-dimensional orthogonal representation of a compact Lie group. We prove that the invariant establishes a bijection between the set of equivariant gradient otopy classes and the direct sum of countably many copies of Z.
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Thermo-oxidative exfoliation of carbon black from ground tire rubber as potential reinforcement in green tires
PublicationConsidering the balance between rapidly growing global tire demand and scarcity of natural resources, recycling and reclaiming techniques of tire rubber have become the state of the art. Herein, we set out to implement a self-designed thermo-oxidative reactor for the exfoliation of carbon black (CB) from ground tire rubber, which is efficiently functioned under a thermo-oxidative reclaiming condition without any additive. The exfoliation...
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Periodic Points for Sphere Maps Preserving MonopoleFoliations
PublicationLet S^2 be a two-dimensional sphere. We consider two types of its foliations with one singularity and maps f:S^2→S^2 preserving these foliations, more and less regular. We prove that in both cases f has at least |deg(f)| fixed points, where deg(f) is a topological degree of f. In particular, the lower growth rate of the number of fixed points of the iterations of f is at least log|deg(f)|. This confirms the Shub’s conjecture in...
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A note on polynomial algorithm for cost coloring of bipartite graphs with Δ ≤ 4
PublicationIn the note we consider vertex coloring of a graph in which each color has an associated cost which is incurred each time the color is assigned to a vertex. The cost of coloring is the sum of costs incurred at each vertex. We show that the minimum cost coloring problem for n-vertex bipartite graph of degree ∆≤4 can be solved in O(n^2) time. This extends Jansen’s result [K.Jansen,The optimum cost chromatic partition problem, in:...
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Bernstein-type theorem for ϕ-Laplacian
PublicationIn this paper we obtain a solution to the second-order boundary value problem of the form \frac{d}{dt}\varPhi'(\dot{u})=f(t,u,\dot{u}), t\in [0,1], u\colon \mathbb {R}\to \mathbb {R} with Sturm–Liouville boundary conditions, where \varPhi\colon \mathbb {R}\to \mathbb {R} is a strictly convex, differentiable function and f\colon[0,1]\times \mathbb {R}\times \mathbb {R}\to \mathbb {R} is continuous and satisfies a suitable growth...
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Multi-pathway mechanism of polydopamine film formation at vertically aligned diamondised boron-doped carbon nanowalls
PublicationBoron-doped carbon nanowall (B:CNW) electrodes were used as a platform for studying the electropolymerisation of dopamine. Due to the unique properties of B:CNW, including the fast charge-transfer kinetics and high surface conductivity, a high degree of reversibility of redox reactions was achieved. Three separated redox peaks were observed on voltammograms and attributed to three fundamental reactions in the dopamine polymerisation...
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Path components of the space of gradient vector fields on the two dimensional disc
PublicationWe present a short proof that if two gradient maps on the twodimensional disc have the same degree, then they are gradient homotopic.
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Ryszard Woźniak dr inż.
PeopleRyszard Woźniak received his M.Sc. (1984) from the Lublin University of Technology specializing in Cars and Tractors. In 2002, at the Gdansk University of Technology he defended his doctoral thesis on: "Tyre/road noise when large longitudinal forces are applied in tyre/road contact patch" and obtained a doctorate degree in technical sciences in the field of construction and operation of machines. Currently he is an adjunct at the...
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Marek Czachor prof. dr hab.
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Piotr Samól dr hab. inż. arch.
PeoplePiotr Samól is an associate professor (profesor uczelni) in the Department of History, Theory and Monument Preservation at Gdansk University of Technology. He graduated in architecture (M.Sc. Eng.) and history (B.A.). His researches are focused on the architectural and urban history of Gdansk and Baltic Sea region. He defended his doctoral thesis (scientifc field: architecture and urban planning) on the architecture of Dominican...
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A closer look at how the dispersive liquid–liquid microextraction method works. Investigation of the effect of solvent mixture composition on the quality and stability of the cloudy state
PublicationThe dispersive liquid–liquid microextraction (DLLME) is one of the most popular miniaturized extraction procedures. In this paper, the degree of dispersion and dispersion stability were studied with the aim to assess the correlations of these parameters with efficiency for the selected analytical application. The dependence between the degree of dispersion (cloudy state quality) and its stability obtained by various emulsification...
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Degree product formula in the case of a finite group action
PublicationLet V, W be finite dimensional orthogonal representations of a finite group G. The equivariant degree with values in the Burnside ring of G has been studied extensively by many authors. We present a short proof of the degree product formula for local equivariant maps on V and W.
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Seiberg-Witten invariants the topological degree and wall crossing formula
PublicationFollowing S. Bauer and M. Furuta we investigate finite dimensional approximations of a monopole map in the case b 1 = 0. We define a certain topological degree which is exactly equal to the Seiberg-Witten invariant. Using homotopy invariance of the topological degree a simple proof of the wall crossing formula is derived.
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Tomasz Jażdżewski mgr inż. arch.
PeopleTomasz Tadeusz Jażdżewski is an assistant in the Department of History, Theory and Monument Preservation at Gdansk University of Technology. Graduated from the Faculty of Architecture with the master degree. Student on Doctoral Studies at the Faculty of Architecture
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The Education of Analytical Chemists in Polish Universities
PublicationAnalytical Chemistry plays a very important role in the modern world. The main reasons are; the need of environmental monitoring, quality of food and water control, human health, quality of industrial production control, nanotechnologies and material science. Together with Inorganic Chemistry, Organic Chemistry and Physical Chemistry, Analytical Chemistry is a fundamental chemical course. The education of Analytical Chemists is...
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Application of Monte-Carlo method to modelling influence of selected soil heterogeneity on macrodispersion of pollutants in unsaturated soil medium
PublicationThe influence of soil heterogeneity on miscible solute transport in soil is analyzed. The transport process is simulated numerically using the Monte-Carlo method. This paper shows how different types of soil heterogeneity influence the process of contaminant spreading. If independent flow paths exist in the soil, the degree of the mixing of pollutants in the outflow from the soil profile is larger. If the preferential flow paths...
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Employment Specialization in the Enlarged European Union
PublicationThis paper presents the evolution of absolute employment specialization along the course of economic growth of 25 EU countries. We focus on the degree to which EU economies concentrate labor force in a few sectors/industries. Using disaggregated statistics classified according to NACE Rev. 1 division (71 sectors) we calculate various synthetic indices measuring the degree of diversification typical for the employment structures...
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The computational complexity of the backbone coloring problem for bounded-degree graphs with connected backbones
PublicationGiven a graph G, a spanning subgraph H of G and an integer λ>=2, a λ-backbone coloring of G with backbone H is a vertex coloring of G using colors 1, 2, ..., in which the color difference between vertices adjacent in H is greater than or equal to lambda. The backbone coloring problem is to find such a coloring with maximum color that does not exceed a given limit k. In this paper, we study the backbone coloring problem for bounded-degree...
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Assessment of the Effectiveness of a Short-term Hearing Aid Use in Patients with Different Degrees of Hearing Loss
PublicationThe study presents evaluating the effectiveness of the hearing aid fitting process in the short-term use (7 days). The evaluation method consists of a survey based on the APHAB (Abbreviated Profile of Hearing Aid Benefit) questionnaire. Additional criteria such as a degree of hearing loss, number of hours and days of hearing aid use as well as the user’s experience were also taken into consideration. The outcomes of the benefit...
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Monika Gwóźdź - Lasoń dr
PeoplePhD Eng. Monika Gwóźdź-Lasoń, REV Diplomas and scientific degrees 28/11/2007 Acquiring the PhD in technical sciences [630000] [630900]; doctoral dissertation entitled Modele Obliczeniowe Podłoża Gruntowego w Aspekcie Różnych Metod i Technologii Wzmocnienia = Numerical models of the subsoil reinforced by different kind of methods and technology. 1995-2000 Obtaining the degree: Master of Science; Faculty of Civil Engineering,...
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COMPARATIVE ANALYSIS OF TRANSPORT ORGANIZATION AND FUNCTIONING OF WATER TRAMS IN GDAŃSK, BYDGOSZCZ AND KRAKÓW
PublicationThe subject of this work is to identify and juxtapose solutions implemented in transport provided by water trams for the following cities: Gdańsk, Bydgoszcz and Kraków. As a result of the conducted analysis of transport factors, the degree of conformity of project objectives to the actual role of the water tram has been determined. It was found that the Kraków Water Tram (also known as Cracow Water Tram) is characterized by the...
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Edge coloring of graphs of signed class 1 and 2
PublicationRecently, Behr (2020) introduced a notion of the chromatic index of signed graphs and proved that for every signed graph (G, σ) it holds that ∆(G) ≤ χ′(G,σ) ≤ ∆(G) + 1, where ∆(G) is the maximum degree of G and χ′ denotes its chromatic index. In general, the chromatic index of (G, σ) depends on both the underlying graph G and the signature σ. In the paper we study graphs G for which χ′(G, σ) does not depend on σ. To this aim we...
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2-outer-independent domination in graphs
PublicationWe initiate the study of 2-outer-independent domination in graphs. A 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 at least two neighbors in D, and the set V(G)\D is independent. The 2-outer-independent domination number of a graph G is the minimum cardinality of a 2-outer-independent dominating set of G. We show that if a graph has minimum degree at least two,...
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Topological degree for equivariant gradient perturbations of an unbounded self-adjoint operator in Hilbert space
PublicationWe present a version of the equivariant gradient degree defined for equivariant gradient perturbations of an equivariant unbounded self-adjoint operator with purely discrete spectrum in Hilbert space. Two possible applications are discussed.