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Search results for: Impact test
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Comparison of Tire Rolling Resistance Measuring Methods for Different Surfaces
PublicationThe rolling resistance of car tires is one of the most important parameters characterizing tires today. This resistance has a very significant contribution to the energy consumption of wheeled vehicles. The climate crisis has forced tire and car manufacturers to place great emphasis on the environmental impact of their products. Paradoxically, the development of electric vehicles has led to an even greater importance of rolling...
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The reasons of considarable deflections of roof trusses in engineering analysis
PublicationThe aim of the paper is to present an unconventional analysis of deformations of roof trusses of an exhibition pavilion. Structure of the main hall of the pavilion consists of repeatable span frames with steel pillars made of I-sections, fastened in the foundations and hinged supporting roof girders. The roof trusses, completed in steel construction, have undergone considerable permanent deflections. Deformations of the lower chord...
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Finding the Right Solvent: A Novel Screening Protocol for Identifying Environmentally Friendly and Cost-Effective Options for Benzenesulfonamide
PublicationThis study investigated the solubility of benzenesulfonamide (BSA) as a model compound using experimental and computational methods. New experimental solubility data were collected in the solvents DMSO, DMF, 4FM, and their binary mixtures with water. The predictive model was constructed based on the best-performing regression models trained on available experimental data, and their hyperparameters were optimized using a newly...
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Price bubbles in commodity market – A single time series and panel data analysis
PublicationThis paper examines thirty-five commodities, grouped into three market sectors (energy, metals, agriculture & livestock) in terms of the occurrence of price bubbles. The study was based on monthly data for each commodity separately and, in a panel approach, for selected sectors and for all commodities combined. The GSADF test and its version for panel data – panel GSADF – were used to identify bubbles. The beginning and end of...
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Novel Biodegradable Potato Starch-based Compositions as Candidates in Packaging Industry, Safe for Marine Environment
PublicationAbout 70 % of our planet’s surface is covered by seas and oceans to which even 10 million tons of waste go every year. It makes these places the largest global landfills, containing up to 90 % of plastic waste. In this article we present the results of research on novel starch-based compositions expected to be more safe for the marine environment. For these purpose biopolymers such as, thermoplastic starch (TPS), polylactide (PLA)...
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Influence of Parameters of Laser Beam Welding on Structure of 2205 Duplex Stainless Steel
PublicationLaser welding is used in modern industry, having many advantages comparing to traditional welding technologies. Nowadays, industry sectors such as shipbuilding, automotive and aviation can’t be imagined without laser processing technologies. Possibility of increase of welded joint properties, autogenous welding and high level of process automation makes the technology of laser welding perspective part of the industry. Physical...
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The effect of external load on ultrasonic wave attenuation in steel bars under bending stresses
PublicationThe stress state in deformed solids has a significant impact on the attenuation of an ultrasonic wave propagating through the medium. Measuring a signal with certain attenuation characteristics can therefore provide useful diagnostic information about the stress state in the structure. In this work, basic principles behind a novel attenuation-based diagnostic framework are introduced. An experimental study on steel bars under three-point...
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The Concept of Using the Decision-Robustness Function in Integrated Navigation Systems
PublicationThe diversity and non-uniformity of the positioning systems available in maritime navigation systems often impede the watchkeeping officer in the selection of the appropriate positioning system, in particular, in restricted basins. Thus, it is necessary to introduce a mathematical apparatus to suggest, in an automated manner, which of the available systems should be used at the given moment of a sea trip. Proper selection of the...
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The lethal effect of hydrotechnical concrete on freshwater Bivalvia
PublicationMost hydrotechnical buildings under construction demand the concrete mixture to be set directly under water. The main reason for such a procedure is to limit the washing away of the the concrete binding mixture and to increase the efficiency of organisation of work so as to ensure continuity in concreting. The impact on the aquatic environment of recent developments in concrete technology and the use of new components has not yet...
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The Impact of Long-Time Chemical Bonds in Mineral-Cement-Emulsion Mixtures on Stiffness Modulus
PublicationDeep cold in-place recycling is the most popular method of reuse of existing old and deteriorated asphalt layers of road pavements. In Poland, in most cases, the Mineral-Cement-Emulsion mixture technology is used, but there are also applications combining foamed bitumen and cement. Mineral-Cement-Emulsion mixtures contain two different binding agents – cement as well as asphalt from the asphalt emulsion. Asphalt creates asphalt...
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NEW SOLUTIONS FOR THE SOLAR CHARGE CONTROLLERS DESIGN FOR OBTAINING TRUE MPP IN PARTLY SHADED PV MODULES
PublicationSoft shading sources such as tree limbs, structural elements of buildings and chimneys, scatter and refract sunlight, significantly reducing the amount of radiation reaching the surface of the module. The hard shadings located directly on the surface (i.e. bird droppings, leaves, snow) tend to stop sunlight completely. These phenomena significantly affects the output characteristics of photovoltaic modules and often contribute...
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Teaching management skills to software develop- ment teams through the lean start-up methodology
PublicationIn order for development teams to understand the impact of software development on value delivery it is important that all team members, including software engineers, possess adequate management skills which not always have been acquired during university education. The lean start-up methodology techniques enable new ventures to test hypothesis, gather customer feed- back and create a minimum viable product. The obtained information...
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Using Statistical Methods to Estimate The Worst Case Response Time of Network Software Running on Indeterministic Hardware Platforms
PublicationIn this paper we investigate whether the statistical Worst Case Execution Time (WCET) estimation methods devised for embedded platforms can be successfully applied to find the Worst Case Response Time (WCRT) of a network application running on a complex hardware platform such as a contemporary commercial off-the-shelf (COTS) system. Establishing easy-to-use timing validation techniques is crucial for real-time applications and...
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NUMERICAL MODEL OF PLASTIC DESTRUCTION OF THICK STEEL STRUCTURAL ELEMENTS
PublicationIn the shipbuilding industry, the risk of brittle fracture of the structure is limited by using certified materials with specified impact strength, determined by the Charpy method (for a given design temperature) and by supervising the welding processes (technology qualification, production supervision, non-destructive testing). For off-shore constructions, classical shipbuilding requirements may not be sufficient. Therefore, the...
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Poroelastic Road Surface – a Promising Road Traffic Noise Abatement Solution
PublicationRoad surfaces have a direct impact on the generation of noise by rolling tyres, the main and dominant source of noise of moving vehicles, as well as may affect propagation of noise emitted by all noise sources of a vehicle. Thus there is no doubt that pavement should be considered as one of the major potential road traffic noise abatement measure. Low noise pavements of existing types may in new conditions provide up to 8 dB of...
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Potential Toxic Effects of Airport Runoff Water Samples on the Environment
PublicationDespite the positive aspects of the intensive development of aviation, airports are considered large-scale polluters. Pollution caused by runoff water (stormwater) is one of the major problems related to airport operations. The aim of this study was to characterize the potential toxic impact on aquatic life from runoff water discharges from four international airports in Europe. Samples of stormwater were collected at airports...
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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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Power System Dynamics. Stability and Control. 3rd edition
PublicationComprehensive, state-of-the-art review of information on the electric power system dynamics and stability. It places the emphasis first on understanding the underlying physical principles before proceeding to more complex models and algorithms. The book explores the influence of classical sources of energy, wind farms and virtual power plants, power plants inertia and control strategy on power system stability. The book cover...
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Analiza trwałości zmęczeniowej asfaltów drogowych i modyfikowanych z wykorzystaniem testu liniowego zwiększania amplitudy / Analysis of the fatigue life of neat and modified bitumens using linear amplitude sweep test
PublicationThe paper presents an evaluation of the fatigue resistance of selected Polish bituminous binders: neat bitumen 50/70, polymer modified bitumen PMB 45/80-55 and polymer highly modified bitumen PMB 45/80-80. The linear amplitude sweep (LAS) test, which is a new bitumen performance grading test developed in the USA, and was used to assess the fatigue life of the bitumens. Highly modified bitumen 45/80-80 showed 10-20 times higher...
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Torque capacity of multidisc wet clutch with reference to friction occurrence on its spline connections
PublicationIn this article developed mathematical model that includes friction occurrence on spline connections is presented. The work also contains results of experimental research on torque capacity of multidisc wet clutch. These results are expressed as a function of contact pressure for different number of friction surfaces. Due to increased interest in research concerning multidisc wet clutches it is essential to determine impact of...
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Study on Microstructural Characterization, Mechanical Properties and Residual Stress of GTAW Dissimilar Joints of P91 and P22 Steels
PublicationThis article deals with the dissimilar joining of two different grade Cr-Mo steel (2.25Cr-1Mo: P22 and modified 9Cr-1Mo: P91) for power plant application. The dissimilar butt-welded joint was produced for conventional V groove design by using the gas tungsten arc welding (GTAW) process with the application of an ERNiCrMo-3 Ni-based super alloy filler. A microstructure characterization was performed to measure the inhomogeneity...
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Minimizing Distribution and Data Loading Overheads in Parallel Training of DNN Acoustic Models with Frequent Parameter Averaging
PublicationIn the paper we investigate the performance of parallel deep neural network training with parameter averaging for acoustic modeling in Kaldi, a popular automatic speech recognition toolkit. We describe experiments based on training a recurrent neural network with 4 layers of 800 LSTM hidden states on a 100-hour corpora of annotated Polish speech data. We propose a MPI-based modification of the training program which minimizes the...
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Digital transformation and economic growth - DESI improvement and implementation
PublicationThe paper aims to improve the methodology of the Digital Economic and Society Index (DESI), the European Commission’s newest index to assess the development of the digital economy. In particular, we investigate whether methodological changes to the structure of DESI improve its ability to capture the digital transformation of EU economies. Using the sensitivity- based analysis, we check whether the selection of weights of individual...
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High frequency test measurements on physical model of power transformer with use of FRAX analyzer Streszczenie. W niniejszym artykule przedstawiono pomiary testowe SFRA wykonane na modelu fizycznym transformatora elektroenergetycznego
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BADANIE WPŁYWU INDUKCJI REMANENCJI NA STAN PRZEJŚCIOWY JEDNOFAZOWEGO UKŁADU TRANSFORMATOROWEGO
PublicationW referacie przedstawiono wyniki badań eksperymentalnych i symulacyjnych wpływu indukcji remanencji w rdzeniu transformatora jednofazowego na jego stan przejściowy przy jego pracy jałowej. Badany obiekt jest układem transformatorowym o dwóch uzwojeniach nawiniętych na zwijanym z blachy anizotropowej rdzeniu w kształcie toroidu. Doświadczenia eksperymentalne polegały na rozładowywaniu kondensatora przez uzwojenie strony pierwotnej...
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Impact response of novel layered two stage fibrous composite slabs with different support type
PublicationThe performance of novel Layered Two Stage Fibrous Composite slabs (LTSFC) was pioneered under falling mass collisions using a combined experimental and numerical study. Such LTSFC slabs consist of three layers with and without the insertion of glass fibre mesh between the layers. LTSFC techniques were used to fabricate the composite slabs with three layers including 3%, 1.5%, and 3% of fibre content for the top, middle, and...
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Ocena wpływu dodatku oliwy z oliwek na degradację termiczną rafinowanego oleju rzepakowego
PublicationTłuszcze jadalne to ważny składnik diety człowieka. Mają one znaczący wpływ na prawidłowe funkcjonowanie ludzkiego organizmu. Podczas smażenia olej podlega przemianom chemicznym, dlatego spożywane tłuszcze powinny charakteryzować się jak największą stabilności oksydacyjnej. Celem prowadzonych badań było określenie jakości olejów rzepakowego, mieszanego oraz rafinowanej oliwy z oliwek, pochodzących z rynku krajowego. Podczas badań...
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Study on Microstructure and Mechanical Properties of Laser Welded Dissimilar Joint of P91 Steel and INCOLOY 800HT Nickel Alloy
PublicationThis investigation attempts to explore the weld characteristics of a laser welded dissimilar joint of ferritic/martensitic 9Cr-1Mo-V-Nb (P91) steel and Incoloy 800HT austenitic nickel alloy. This dissimilar joint is essential in power generating nuclear and thermal plants operating at 600–650 °C. In such critical operating conditions, it is essential for a dissimilar joint to preserve its characteristics and be free from any kind...
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Thermomechanical and Fire Properties of Polyethylene-Composite-Filled Ammonium Polyphosphate and Inorganic Fillers: An Evaluation of Their Modification Efficiency
PublicationThe development of new polymer compositions characterized by a reduced environmental impact while lowering the price for applications in large-scale production requires the search for solutions based on the reduction in the polymer content in composites’ structure, as well as the use of fillers from sustainable sources. The study aimed to comprehensively evaluate introducing low-cost inorganic fillers, such as copper slag (CS),...
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Preliminary Testing of the Influence of Modified Polycaprolactones on Anabaena Variabilis Growth in Seawater
PublicationSeveral new biodegradable polymer materials have recently come onto the global market. Mostly the results on degradation kinetic studies are presented. This paper suggests using one of the tests to estimate the impact of polymer packaging material on sea life. The microorganism chosen was Anabaena variabilis (identified in many waters, including those of the Baltic Sea, especially in the Gulf of Gdansk and Puck Bay; this cyanobacterium...
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Assessment of the application of CEM III with exposed aggregate as an alternative to CEM I for road pavements
PublicationThe article presents a results of study on the impact of replacing CEM I SR3/NA by CEMIII/A LH/HSR/NAon the mechanical properties and durability of pavement concrete with exposed aggregate. Was used granite aggregate and washed sand. Water/cement () ratio in the tested concretes constituted 0.35 and 0.4 and part of the cement was replaced with a 5% addition of natural pozzolana – zeolite. Compressive strength tests were performed...
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Selected Technical Issues of Deep Neural Networks for Image Classification Purposes
PublicationIn recent years, deep learning and especially Deep Neural Networks (DNN) have obtained amazing performance on a variety of problems, in particular in classification or pattern recognition. Among many kinds of DNNs, the Convolutional Neural Networks (CNN) are most commonly used. However, due to their complexity, there are many problems related but not limited to optimizing network parameters, avoiding overfitting and ensuring good...
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Ti/TiO2 nanotubes sensitized PbS quantum dots as photoelectrodes applied for decomposition of anticancer drugs under simulated solar energy
PublicationOne of the challenges in research into photoelectrocatalytic (PEC) degradation of pollutants is finding the appropriate photoanode material, which has a significant impact on the process efficiency. Among all others, photoelectrodes based on an ordered TiO2 nanotube arrays are a promising material due to well-developed surface area and efficient charge separation. To increase the PEC activity of this material, the SILAR method was...
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Experimental study of the impact of notches and holes made in the front edge of adherends on the properties of static and fatigue strength of adhesive joints
PublicationThe paper presents the results of experimental studies aimed at determining the effect of holes and notches at the front edge of adherends on the strength of adhesive joints. Single-lap joints made of S235JR steel sheets joined with Araldite 2014-2 epoxy adhesive were tested. Comparative tests of static strength in the shear test as well as high-cycle fatigue strength tests were carried out. Joints with three holes with a diameter...
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Surface treatment of C80U steel by long CO2 laser pulses
PublicationThe paper presents the results of laser-melted C80U steel. The processed steel was placed between two permanent magnets and laser beam whose scanning velocity was 10 mm/s. CO2 laser beam was working in pulse mode. Pulses were generated at 100% of the average preset power of 700W, with 45 ms irradiation, zero interval between pulses and beginning of pulse repetition upon the achievement of the average laser power. During the operation,...
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Bioassays as one of the Green Chemistry tools for assessing environmental quality: A review
PublicationFor centuries, mankind has contributed to irreversible environmental changes, but due to the modern science of recent decades, scientists are able to assess the scale of this impact. The introduction of laws and standards to ensure environmental cleanliness requires comprehensive environmental monitoring, which should also meet the requirements of Green Chemistry. The broad spectrum of Green Chemistry principle applications should...
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The effect of social media communication on consumer perceptions of brands
PublicationResearchers and brand managers have limited understanding of the effects social media communication has on how consumers perceive brands. We investigated 504 Facebook users in order to observe the impact of firm-created and user-generated (UG) social media communication on brand equity (BE), brand attitude (BA) and purchase intention (PI) by using a standardized online survey throughout Poland. To test the conceptual model, we...
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Detecting type of hearing loss with different AI classification methods: a performance review
PublicationHearing is one of the most crucial senses for all humans. It allows people to hear and connect with the environment, the people they can meet and the knowledge they need to live their lives to the fullest. Hearing loss can have a detrimental impact on a person's quality of life in a variety of ways, ranging from fewer educational and job opportunities due to impaired communication to social withdrawal in severe situations. Early...
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Relationship between Chemical Structure and Biological Activity Evaluated In Vitro for Six Anthocyanidins Most Commonly Occurring in Edible Plants
PublicationNumerous studies have provided evidence that diets rich in anthocyanins show a broad spectrum of health benefits. Anthocyanins in nature are usually found in the form of glycosides. Their aglycone forms are called anthocyanidins. The chemical structure of anthocyanins is based on the flavylium cation, but they differ in the position and number of substituents. However, the bioactives and foods that contain them are frequently treated...
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Resource productivity and environmental degradation in EU-27 countries: context of material footprint
PublicationThis study explores the relationship between the resource productivity and environmental degradation in European Union-27 countries. This study tests this relationship in context of high, moderate, and low material footprint sub-samples; these samples are formed utilizing the expectation–maximization machine learning algorithm. Using the panel data set of EU-27 countries from 2000 to 2020, linear and non-linear autoregressive distributed...
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Testing the Effect of Bathymetric Data Reduction on the Shape of the Digital Bottom Model
PublicationDepth data and the digital bottom model created from it are very important in the inland and coastal water zones studies and research. The paper undertakes the subject of bathymetric data processing using reduction methods and examines the impact of data reduction according to the resulting representations of the bottom surface in the form of numerical bottom models. Data reduction is an approach that is meant to reduce the size...
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ENERGY ANALYSIS OF THE PROPULSION SHAFT FATIGUE PROCESS IN A ROTATING MECHANICAL SYSTEM PART II IDENTIFICATION STUDIES – DEVELOPING THE FATIGUE DURABILITY MODEL OF A DRIVE SHAFT
PublicationThe article presents a continuation of research carried out concerning identification of energy consequences of mechanical fatigue within a propeller shaft in a rotating mechanical system, while working under conditions of the loss of the required alignment of shaft lines. Experimental research was carried out on a physical model reflecting a full-sized real object: i.e., the propulsion system of the ship. It is proven, by means...
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The geodetic monitoring of the engineering structure – a practical solution of the problem in 3D space
PublicationThe study raises the issues concerning the automatic system designed for the monitoring of movement of controlled points, located on the roof covering of the Forest Opera in Sopot. It presents the calculation algorithm proposed by authors. It takes into account the specific design and location of the test object. High forest stand makes it difficult to use distant reference points. Hence the reference points used to study the stability...
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Psychological capital and happiness at work: The mediating role of employee thriving in multinational corporations
PublicationWorking in multicultural work environments of multinational corporations (MNCs) creates challenges whose expected impact on happiness is equivocal. In the following paper, we examine the relationship between psychological capital and happiness at work in the specific MNCs’ context. We assume that thriving (eudemonic well-being) at work fosters individuals’ development and enhances their happiness composed of both the affective...
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Study on Microstructure-Property Relationship of Inconel 617 Alloy/304L SS Steel Dissimilar Welds Joint
PublicationWelding of Inconel 617 (IN617) alloy and austenitic 304L SS steel has been attempted using the autogenous Laser Beam Welding (LBW) process. Characterization of dissimilar weldments was performed on either side of the fusion boundaries. The metallographic results showed that the inhomogeneous microstructure formation for weld metal contained columnar and cellular dendrites near the interface, whilst the columnar, cellular and equiaxed...
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Wyznaczanie współczynnika przejmowania ciepła podczas wrzenia w przepływie dwutlenku węgla (Prediction of flow boling heat transfer coefficient for carbon dioxide in minichannels)
PublicationW pracy przedstawiono wyniki obliczeń uzyskane za pomocą własnego modelu półemirycznego dla wybranych danych eksperymentalnych dla wrzenia w przepływie dwutlenku węgla. Metoda obliczeniowa została zweryfikowana z danymi eksperymentalnymi Docoulombiera i innych (2011) oraz Mastrullo i innych (2009). Badania eksperymentalne dotyczą pełnego zakresu zmienności stopnia suchości oraz zakresu prędkości masowej G=200-1200 kg/m2s. rozwijany...
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Ocena klimatu akustycznego w przestrzeni pasażerskiej elektrycznego zespołu trakcyjnego serii EN57
PublicationW pracy przedstawiono wyniki badań poziomów dźwięku w przestrzeni pasażerskiej elektrycznego zespołu trakcyjnego (EZT) serii EN57 podczas postoju, rozruchu, jazdy oraz hamowania. Badania przeprowadzono na podstawie autorskiej metodyki badawczej bazując na normie PNEN ISO 3381:Kolejnictwo. Akustyka. Pomiar hałasu wewnątrz pojazdów szynowych. Badania przeprowadzono na linii kolejowej nr 250 od przystanku Gdańsk Śródmieście do stacji...
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Poroelastic Road Surfaces - State of The Art
PublicationPoroelastic Road Surfaces (PERS) constitute a specific group of pavements containing a great amount of crumbled rubber. In most cases rubber aggregate constitutes about 20% of the mixture (by weight) and a polyurethane resin is used as a binder. As a result, PERS is characterized by a much higher elasticity than asphalt and a high porosity typical for drainage pavements. Due to this, tire/road noise is greatly reduced and on top...
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Merton-type default risk and financial performance: the dynamic panel moderation of firm size
PublicationPurpose – The main purpose of this study is to evaluate the probability of default and examine the relationship between default risk and financial performance, with dynamic panel moderation of firm size. Design/methodology/approach – This study utilizes a total of 1,500 firm-year observations from 2013 to 2018 using dynamic panel data approach of generalized method of moments to test the relationship between default risk and financial...
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Robust and Efficient Machine Learning Algorithms for Visual Recognition
PublicationIn visual recognition, the task is to identify and localize all objects of interest in the input image. With the ubiquitous presence of visual data in modern days, the role of object recognition algorithms is becoming more significant than ever and ranges from autonomous driving to computer-aided diagnosis in medicine. Current models for visual recognition are dominated by models based on Convolutional Neural Networks (CNNs), which...