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Search results for: Facture
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DEM modelling of concrete fracture based on its structure micro-CT images
PublicationW rozdziale książki zawarto numeryczne wyniki mezoskopowe dotyczące postępującego pękania betonu na poziomie kruszywa. Do badania procesu pękania belki betonowej z karbem w trzech (3D) i dwóch (2D) wymiarach zastosowano metodę elementów dyskretnych (DEM). Niejednorodność betonu uwzględniono stosując czterofazowy opis: kruszywo, zaprawa, makropustki i międzyfazowe strefy przejściowe. W obliczeniach DEM na podstawie zdjęć rentgenowskich...
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Effect of aggregate structure on fracture process in concrete using 2D lattice model
PublicationArtykuł przedstawia symulacje rys w betonie przy zastosowaniu nowego modelu siatkowego. Zbadano wpływ rozkładu i wielkości kruszywa oraz wpływ strefy kontaktu na nośność i propagacje rys. Obliczenia były dwuwymiarowe.
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Measurements and calculations of the width of the fracture process zones on the surface of notched concrete beams
PublicationArtykuł omawia wyniki pomiaru i analizy numerycznej szerokości strefy pękania w belkach betonowych z nacięciem. Do pomiarów zastosowano metodę DIC. Do symulacji zastosowano model sprężysto - plastyczny i model z degradacją sztywności. Oba modele zostały rozszerzone o nielokalne osłabienie. Wyniki symulacji porównano z doświadczeniami.
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Discrete modeling of micro-structure evolution during concrete fracture using DEM
PublicationW artykule pokazano wyniki dyskretne DEM dla betonu poddanego ściskaniu i rozciąganiu jednoosiowemu. Wyniki siła-przemieszczenie i zarysowania porównano z doświadczeniami. Szczególną uwagę zwrócono na zjawiska mikrostrukturalne podczas zarysowania na poziomie kruszywa.
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SIMULATIONS OF FRACTURE IN CONCRETE BEAMS UNDER BENDING USING A CONTINUUM AND DISCRETE APPROACH
PublicationThe paper describes two-dimensional meso-scale results of fracture in notched concrete beams under bending. Concrete was modelled as a random heterogeneous 4-phase material composed of aggregate particles, cement matrix, interfacial transitional zones and air voids. Within continuum mechanics, the simulations were carried out with the finite element method based on a isotropic damage constitutive model enhanced by a characteristic...
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Country Safety Performance Function and the factors affecting it
PublicationW artykule przedstawiono metodę modelowania wpływu wybranych czynników na liczbę ofiar śmiertelnych na poziomie światowym. Do budowy modeli wykorzystano podejście bazujące na ryzyku. Wykorzystano dane z kilkudziesięciu krajów świata.
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The Factors Affecting Group Identity of Cluster Structures
PublicationThe paper provides a new approach to cluster analysis, basing on a sociologically rooted concept of identity. The authors state that identity in cluster structures is formed by two main groups of factors – uncontrollable or slightly controllable factors (identity mix) and factors that can be fully controlled by a cluster initiative (corporate identity mix). It means that the cluster coordinator is able to consciously build the...
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Functional safety analysis including human factors
PublicationThe article addresses selected aspects of human factors that should be taken into account during the design of safety-related functions for a complex hazardous installation and its protections. In such installations the layer of protection analysis (LOPA) methodology is often used for simplified risk analysis based on defined accident scenarios. To control the risk the safety instrumented functions (SIFs) are identified and their...
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Functional Safety Analysis including Human Factors
PublicationIn this paper selected aspects of human factors are discussed that should be taken into account during the design of safety-related functions for a complex hazardous installation and its protections. The layer of protection analysis (LOPA) methodology is used for simplified risk analysis based on defined accident scenarios. To control the risk the safety instrumented functions (SIFs) are identified and their safety integrity levels...
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Factors that strengthen and weaken the identity of the cluster structures
PublicationThe main aim of this paper is the application of "identity" to the issues related to "clustering process" and particularly - to the cooperation in the clusters and the cluster initiatives. The authors distinguish these factors that have the greatest influence on the formation and maintenance of identity in mentioned networks of cooperation.
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Determination of Failure Causes of a Steam Turbine Casing
PublicationThe paper presents results of research and failure analysis undertaken to determine failure causes of a steam turbine casing. After 130,000 hours of service the crack in a outer shell of the turbine casing was found. The inner shell of the casing was made of cast steel grade G21CrMoV5-7, and the outer shell of grade G20CrMo4-5. Following research were performed in order to determine causes of the casing failure: chemical analysis;...
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Is Germany a Hub of ‘Factory Europe’ for CEE Countries?
PublicationThe goal of the paper is to decompose gross exports and imports to/from Germany for seven selected economies in Central and Eastern Europe (CEE): the Czech Republic, Estonia, Hungary, Lithuania, Latvia, Poland and Slovakia for 2000 and 2014, in order to identify the role of Germany in absorbing, reflecting and redirecting CEE trade. The authors use a gross trade decomposition proposed by Bonin and Mancini (2017), which is the extended...
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Investigating Feature Spaces for Isolated Word Recognition
PublicationMuch attention is given by researchers to the speech processing task in automatic speech recognition (ASR) over the past decades. The study addresses the issue related to the investigation of the appropriateness of a two-dimensional representation of speech feature spaces for speech recognition tasks based on deep learning techniques. The approach combines Convolutional Neural Networks (CNNs) and timefrequency signal representation...
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Increasing rail life by forecasting fatigue failure.
PublicationReferat poświęcony jest przedłużaniu żywotności szyn i obejmuje zagadnienia prognozowania liczby pęknięć a także planowania szlifowań szyn. Dane pomiarowe pochodzą z wieloletnich badań przeprowadzonych w Katedrze Inżynierii Kolejowej Politechniki Gdańskiej na liniach magistralnych PKP.
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Angels drawing a picture JAPAN | INTERNATIONAL EXHIBITION
PublicationPolskie dziedzictwo reprezentowane w pracach młodych uczestników z Polski dzięki powołaniu RWYC Poland i aktywnej działalności na polu edukacji powszechnej. Konkursy realizowane były jesienią 2023 roku w ramach międzynarodowego projektu pod auspicjami UNESCO – Reconnecting WIth Your Culture POLAND. W Japonii odbyły się 4 wystawy z udziałem prac uczestników z całego świata, w tym wybranych przez RWYC Poland. Lokalizacje wystaw...
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Biomechanical causes for failure of the Physiomesh/Securestrap system
PublicationThis study investigates the mechanical behavior of the Physiomesh/Securestrap system, a hernia repair system used for IPOM procedures associated with high failure rates. The study involved conducting mechanical experiments and numerical simulations to investigate the mechanical behavior of the Physiomesh/Securestrap system under pressure load. Uniaxial tension tests were conducted to determine the elasticity modulus of the Physiomesh...
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Contribution of dynamic vehicle loads to pavement failure
PublicationPavement surfaces are not ideally even, which causes dynamic loads of vehicle axles. Distribution of dynamic loads of a given axle is similar to normal distribution and can be described by static load and dynamic load coefficient. The dynamic load coefficient depends on road profile, vehicle speed, properties of suspensions and static load of axle. While for a given road section road profile remains constant, vehicle speed and...
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ANALYSIS OF THE PUNCHING FAILURE MECHANISM IN WORKING PLATFORMS
PublicationPaper presents an analysis of the shear failure mechanism which occurs from the punching of a working platform layer in relation to its thickness, grain size arrangement and mechanical properties, taking into consideration the interaction with soft subgrade. The study is based on the observations of performance of natural scale structures (Streefkerk) and the results of model investigations numerically represented with the use...
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Numerical simulation of laminate composite specimens failure
PublicationThis work presents some numerical results concerning simulation of failure of laminate composite specimens. In the article two tests to determine ultimate strength in an orthotropic layer, are considered: tension (TT1) and compression (TC1) test. The outcome is compared with experimental data provided by [9,10].
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Failure Analysis of footbridge made of composite materials
PublicationFinite element method analysis of a pedestrian footbridge made of sandwich material is presented. The internal structure of the material is modelled as a structural shell assuming the Equivalent Single Layer approach (ESL). Two FEM commercial codes are employed. The response of the structure is studied in order to determine the load level that activates Hashin and Tsai-Wu failure criteria. Some practical aspects of designing footbridges...
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Application of additional factors supporting the microextraction process
PublicationDue to the fact that green analytical chemistry is of high importance, the past two decades have witnessed a rapid growth in the sample preparation area with special emphasis on simplification, miniaturization and automation of extraction procedures. In addition, to accelerate the extraction processes and to improve the separation of analytes, several enhanced parameters are applied. These factors include, ultrasounds, microwaves,...
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AutoCAD: Examination of Factors Influencing User Adoption
PublicationThe primary purpose of the research is to examine and validate determinants of user intention to use AutoCAD software, utilising the constructs from prior studies in a more integrated model. The paper proposes a revised Technology Acceptance Model (TAM) for measuring the adoption of AutoCAD. In the study, a latent construct PPA (perceived physical accessibility) was added to the proposed research model as a new determinant of AutoCAD...
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Feature extraction in detection and recognition of graphical objects
PublicationDetection and recognition of graphic objects in images are of great and growing importance in many areas, such as medical and industrial diagnostics, control systems in automation and robotics, or various types of security systems, including biometric security systems related to the recognition of the face or iris of the eye. In addition, there are all systems that facilitate the personal life of the blind people, visually impaired...
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Analysis of Factors Influencing the Prices of Tourist Offers
PublicationTourism is a significant branch of many world economies. Many factors influence the volume of tourist traffic and the prices of trips. There are factors that clearly affect tourism, such as COVID-19. The paper describes the methods of machine learning and process mining that allow for assessing the impact of various factors (micro, mezzo and macro) on the prices of tourist offers. The methods were used on large sets of real data...
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Creep failure prediction of pipelines in elevated temperature
PublicationW pracy omówiono zastoswanie modelu konstytutytwnego pełzania pozwalającego na analizę trwałości metalowych ruruciągów pracujących w wysokich temperaturach. Zaprezentowano wyniki obliczeń opartych na metodzie elementów skończonych (MES) wykonanych z wykorzystaniem procedur użytkownika w komercyjnym programie MES. Porównano wyniki dla dwóch typów 4-węzłowych elementów powłokowych.
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Factors affecting credibility of e-shops in Poland
PublicationArtykuł stanowi kontynuację tematu podjętego w poprzednich pracach autora nt. czynników wpływających na wiarygodność detalicznych sklepów internetowych. Przedstawiono w nim wstępne wyniki badań dokonanych przez autora. W artykule wskazano również na związki pomiędzy modelami wiarygodności i powszechnie stosowanymi modelami jakości.
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Factors affecting response to biologic treatment in psoriasis
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Conductivity of Fibre Composites with Fractures on the Boundary of Inclusions
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Analisys of the failure of fixator used in bone surgery
PublicationThe Gamma nail (fixator) made of stainless steel, which has broken in the body, was subjected to examination. The fixator was removed from the patient femur. The fracture occurred in the area of the nail hole after two months' stay in the organism. The research included chemical composition, hardness of the Gamma nail material and the observation and analysis of the type of fracture. The research showed the fatigue failure of the...
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Rhinological factors predisposing to headaches: our experience.
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The Stance, Factors, and Composition of Competitiveness of SMEs in Poland
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Genetic Predisposition for Osteoporosis and Fractures in Postmenopausal Women
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Factors affecting credibility of e-shops in Poland
PublicationArtykuł stanowi kontynuację tematu podjętego w poprzednich pracach autora nt. czynników wpływających na wiarygodność detalicznych sklepów internetowych. Przedstawiono w nim wstępne wyniki badań dokonanych przez autora.
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Cluster-Dependent Feature Selection for the RBF Networks
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Pertussis: History of the Disease and Current Prevention Failure
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Investigating Feature Spaces for Isolated Word Recognition
PublicationThe study addresses the issues related to the appropriateness of a two-dimensional representation of speech signal for speech recognition tasks based on deep learning techniques. The approach combines Convolutional Neural Networks (CNNs) and time-frequency signal representation converted to the investigated feature spaces. In particular, waveforms and fractal dimension features of the signal were chosen for the time domain, and...
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On some accuracy limiting factors in wood sawing
PublicationPrzedstawiono szczegółową klasyfikację czynników determinujących dokładność przecinania drewna piłami. Uwzględniono w niej również pozorną utratę dokładności wynikającą z anatomicznej budowy drewna i metody pomiaru (wykorzystywanie lasera). Występujące błędy przecinania zobrazowano szeregiem przykładów z badań doświadczalnych.
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Phospholipids as potential prevention factor in carcinogenesis
PublicationPhospholipids are a group of complex lipids, which can be used in cancer chemoprevention. Glicerophospholipids are composed of fatty acids esterified to a glycerol backbone, a phosphate group and a hydrophilic residue such as: cho- line, ethanoloamine, serine or inositol. In the sn-2 position of glicerophospholipid usually there are unsaturated fatty acids, i.e. linolenic acid, while in the sn-1 position more typi- cal are saturated...
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The role of the human factor in the companies' innovativeness
PublicationInnovation is one of the factors enabling the development of both individual companies and entire economies. While previously the possibilities offered by technology were focused on, including information and communication technology (ICT), recently the potential of human resources has been gaining more and more attention. This capital — often underestimated — can in the right conditions and with a conducive organizational culture...
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Lightweight structures in architecture: scenarios for the future
PublicationLightweight structures - structures with a reduced weight, which otherwise retain the qualities necessary for the building performance, ensuring a proper durability and strength, safety, indoor environmental quality and energy efficiency; stuctures which strive for the optimization of structural systems - are in tune with current trends and socio-economic, environmental and technological factors. The growing interest in the lightweight...
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The Sustainable Link - the Haze of the Past in the Future
PublicationThe aim of the topic is to explore the site by focusing on historical elements and life cycle thinking. The history and sustainability will thereby be the core approach and method during the ongoing design process. These themes will encourage the interdisciplinary and iterative design process.
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Smart skills and education in a future economy
PublicationWhether the role of education is to prepare people for employment or to have meaningful lives in general, it will identify and develop skills and competencies, as well as vocational and personal attributes. Skills, such as critical thinking, novel ideation, and complex cognitive and social skills, are areas where humans continue to outperform smart machines. The purpose of this article is to review the skills and competencies that...
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Future Skills and Education in a Computerized World
PublicationAs computerization of Western economies has advanced, the supply of the demand for routine cognitive tasks and routine manual tasks has fallen. Computerization has increased labour input of nonroutine cognitive tasks which has favourized high educated workers. Similarly, there is clear evidence of an increase in demand for high skilled workforce which originates from poor machine performance of nonroutine...
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An Overview of Sport and the Future Smart Cities
PublicationOne of the main challenges for future cities is to strengthen the role of people and their activities. Therefore, sport provides an opportunity to engage in physical activity, connecting citizens to the city. The question of how sport influences the development of cities and the concept of future smart cities arises. The aim of this study is to examine the relationship between sport and the concept of smart cities by identifying...
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Education as a Stimulating Factor for Entrepreneurship Development
PublicationThe main purpose of the paper is to present the role of entrepreneurial education for entrepreneurship development. The paper is theoretical and includes both a literature review and world reports (Global Entrepreneurship Monitor and WEF Global Education Initiative) on entrepreneurship and entrepreneurial education.
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Virtual teachers - a future or just a dream?
PublicationRozdział dotyczy tematyki inteligentnych systemów uczących, w tym szczególny nacisk jest położony na wizualizowane postaci pojawiające się w systemach zdalnej edukacji (wirtualni mentorzy, wirtualni nauczyciele). Rozdział wskazuje cele budowania wirtualnych nauczycieli i pokazuje wybrane zadania, które mogą one realizować. Opisuje kilka przykładów wirtualnych mentorów, w tym bota wirtualnego nauczyciela GERDA tworzonego na Wydziale...
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Green Chemistry - current and future issues
PublicationW pracy przedstawiono 12 zasad Zielonej Chemii oraz wybrane przykłady stosowania zasad w życiu codziennym, przemyśle, laboratoriach i edukacji. Pokrótce opisano historię Zielonej Chemii oraz przyszłe wyzwania. ZCH dotyczy nowego podejścia do zagadnienia syntezy, przeróbki i wykorzystania związków chemicznych, związanego ze zmniejszeniem zagrożenia dla zdrowia i środowiska. Istnieje wiele publikacji opisujących metodyki analityczne...
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How much is Impact Factor worth?
PublicationThe purpose of this work is to present an aspect of counting citations, which is correlated to the Impact Factor, very important for journals in scientific communication, and provides information about the position of a scientific journal in a particular research area. Sometimes citations don’t count in a research output, e.g. if an article is published in a predatory journal. Those journals ...
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City disstribution logistics as an environmental factor
PublicationPrzedstawiono związki pomiędzy systemami logistyki miejskiej i środowiskiem. Omówiono zadania administracji lokalnej w usprawnieniu dostaw oraz usuwaniu odpadów. Przeprowadzono wariantową analizę działań podejmowanych przez administratora obszaru miejskiego w celu poprawy jakości środowiska.
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Applications of the Future Internet Engineering Project
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