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Search results for: FORCE ALLOCATION
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Liquid residence time in vortex separators
PublicationCentrifugal force enhances gravitational separation of suspension (vortex separators), as well as allows regulation of liquid discharge (vortex flow controls). Furthermore, it elongates the effective residence time of liquid inside the chamber in comparison to non-circulative flow. Laboratorz measurements, described in the paper, indicate that average liquid residence time for circulative flow exceeds 50% of plug-flow time,...
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Theoretical study of thermofrictional oscillations due to negative friction-temperature characteristic
PublicationAnalytical study on oscillations of a body on a moving counterbody has been done by assuming imperfect frictional thermal contact and friction that decreases with contact temperature. It has been shown that stick-slip oscillation occurs due to decrease of friction coefficient when the body moves in the opposite direction to the counterbody. Dynamical characteristics, such as conditions for stable sliding and limit cycles, have...
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Towards an efficient multi-stage Riemann solver for nuclear physics simulations
PublicationRelativistic numerical hydrodynamics is an important tool in high energy nuclear science. However, such simulations are extremely demanding in terms of computing power. This paper focuses on improving the speed of solving the Riemann problem with the MUSTA-FORCE algorithm by employing the CUDA parallel programming model. We also propose a new approach to 3D finite difference algorithms, which employ a GPU that uses surface memory....
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Shaping the new face of the Imperial Shipyard in Gdańsk
PublicationThe main purpose of the article is to present the transformation process of the urban complex known as the Imperial Shipyard in Gdańsk. Its rich history and interesting location on the waterfront of the city as well as its proximity to the very centre makes this area a much sought-after location for the new urban development project, which is part of the wider new district in the city centre of Gdańsk – the Young City. The article...
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Locating and Identifying Ferromagnetic Objects
PublicationThe new non-iterative method of determining the dipole moment and location is presented in this paper. The algorithm of an object's localization and identification was achieved by using numerical calculations and approximation method. The arbitrary shapes of an object were assumed in the identification algorithm - axially symmetric spheroid (a prolate and an oblate). Several examples of localization and identification of an object's...
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Locating and Identifying Ferromagnetic Objects
PublicationThe new non-iterative method of determining the dipole moment and location is presented in this paper. The algorithm of an object's localization and identification was achieved by using numerical calculations and approximation method. The arbitrary shapes of an object were assumed in the identification algorithm - axially symmetric spheroid (a prolate and an oblate). Several examples of localization and identification of an object's...
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ECONOMIC MEASURES AGAINST A PANDEMICS
PublicationThe appropriate level of treatment during periods of increasing workload in the health care system or a particular hospital is ensured either by changing the organization of the system and the principles of use of resources such as space, staff and consumables or their redistribution, or by financial resources such resources are increased or replenished. This article contributes to improve the concept of resource allocation as...
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Game theory-based virtual machine migration for energy sustainability in cloud data centers
PublicationAs the demand for cloud computing services increases, optimizing resource allocation and energy consumption has become a key factor in achieving sustainability in cloud environments. This paper presents a novel approach to address these challenges through an optimized virtual machine (VM) migration strategy that employs a game-theoretic approach based on particle swarm optimization (PSO) (PSO-GTA). The proposed approach leverages...
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Development and validation of lumbar spine finite element model
PublicationThe functional biomechanics of the lumbar spine have been better understood by finite element method (FEM) simulations. However, there are still areas where the behavior of soft tissues can be better modeled or described in a different way. The purpose of this research is to develop and validate a lumbar spine section intended for biomechanical research. A FE model of the 50th percentile adult male (AM) Total Human Model for Safety...
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INVESTIGATION OF THE EFFECT OF THE ROCKET'S SUBORBITAL FLIGHT ON BIOFILM, ENZYMES AND BIOSYNTHESIS ON AUTONOMOUS, MODULAR AND SCALABLE PLATFORM FOR CONDUCTING EXPERIMENTS OF AN ASTROBIOTECHNOLOGICAL NATURE
PublicationWith new incentives for human space exploration, biotechnological experiments in orbit became imperative.Answering this need, we build an autonomous, modular, and scalable platform that enables those experiments onrockets. We called it AMBER. The aim of the payload of the R6 suborbital rocket is to perform an experiment tostudy the influence of rocket flights on biofilm, molecular...
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Determinants of the primary stability of cementless acetabular cup implants: A 3D finite element study
PublicationPrimary stability of cementless implants is crucial for the surgical success and long–term stability. However, primary stability is difficult to quantify in vivo and the biomechanical phenomena occurring during the press–fit insertion of an acetabular cup (AC) implant are still poorly understood. The aim of this study is to investigate the influence of the cortical and trabecular bone Young's moduli Ec and Et, the interference...
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Mechanizm współpracy z gruntem pali prefabrykowanych wbijanych w świetle próbnych obciążeń pali oprzyrządowanych
PublicationOpis badań i wyniki próbnych obciążeń statycznych dwóch pali prefabrykowanych wbijanych oprzyrządowanych w aparaturę do pomiaru rozkładu siły osiowej wzdłuż trzonu pala. Analiza wpływu czasu i procesu wbijania na charakterystykę osiadania pali prefabrykowanych wbijanych. Identyfikacja siły rezydualnej w palu prefabrykowanym wbijanym i jej wpływ na interpretację pomiarów ekstensometrycznych w próbnym obciążeniu pala. Wnioski na...
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Shrinking-shifting and amplifying-shifting device using transformation optics
PublicationBased on transformation optics (TO), this paper uses geometric divisions and linear coordinate transformations to design “shrinking-shifting—and reshaping”, and “amplifying-shifting—and reshaping” devices. The proposed devices can reshape the sizes and locations of the wrapped-objects inside the core-region. The shrinking-shifting device shrinks the larger object into a smaller one and shifts it to different location, whereas the...
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Speciation of heavy metals in wastewater and rejected waters from multistage bioreactors (MUCT)
PublicationThe objective of the study is to investigate the occurrence and availability of selected heavy metals after subsequent stages of treatment in WWTP with activated sludge (enhanced biological N and P removal). To achieved the target it was necessary to recognize the allocation of selected heavy metals between aqueous and solid phase in wastewater and reject waters. Application of sequential extraction of such metals as Cd Zn, Pb,...
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Simulation studies into quayside transport and storage yard operations in container terminals
PublicationThe focus of the paper is on quayside transport and storage yard operations in the sea container terminals. Developed algorithms for solving the issues of load handling and storage space allocation have been applied in the frame of adopted simulation model. The criteria chosen for decision making involved the total makespan of vessel unloading and the utilisation levels of the transportation trucks. Recommendations for unloading...
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Microseismic Monitoring of Hydraulic Fracturing - Data Interpretation Methodology With an Example from Pomerania
PublicationMicroseismic monitoring is a method for localizing fractures induced by hydraulic fracturing in search for shell gas. The data is collected from an array of geophones deployed on the surface or underground. Ground vibrations are recorded and analysed for fracture location, magnitude and breakage mechanism. For successful microseismic monitoring one need a velocity model of underlying formations. The model is further tuned with...
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System monitoringu odbieraków prądu pojazdów kolejowych w aspekcie bezpieczeństwa i ciągłości ruchu.
PublicationOmówiono metodę monitorowania stanu technicznego odbieraków prądu w oparciu o pomiar uniesienia przewodów jezdnych sieci trakcyjnej w czasie przejazdu pociągu. Opisano konstrukcję i zasadę działania wdrożonego na linii kolejowej pilotażowego stanowiska monitoringu. Przedstawiono metodę analizy i sposób wizualizacji wyników pomiarów. Zastosowany algorytm szacowania siły statycznej odbieraka uwzględnia prędkości pociągu i działanie...
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Optymalizacja doboru prawa konstytutywnego membrany o strukturze plecionej
PublicationCelem niniejszej dysertacji jest opracowanie zagadnienia optymalizacyjnego pozwalającego dobrać model konstytutywny opisujący mechaniczne zachowanie membrany technicznej. Do analizy wybrano membrany plecione, stosowane w medycynie, tzw. siatki chirurgiczne. W celu wykonania identyfikacji praw konstytutywnych, wykonano dwuosiowe rozciąganie próbek materiałów, otrzymując wskazanie na nieliniowe anizotropowe zachowanie materiałów....
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Problems of Flaking in Strengthening Shaft Burnishing
PublicationThe article presents the results of testing the surface condition of shafts manufactured by a strengthening rolling burnishing process. The shafts with a hardness about 220 HB were burnished with a roller with different force. Researches were carried out with particular attention to the structure of the outflowing material in the tool zone during burnishing process. The article presents the results of the examinations of burnished...
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Informal employment in Poland: an empirical spatial analysis
PublicationThe main goal of our article is to bridge the gap in the regional analysis of informal employment in Poland and in particular to indicate the propensity for informal work in the working-age population, to test if informal activities are typical for marginalized people (less educated, unemployed, older) and to identify the regional and spatial heterogeneity in the propensity. We use data from the ‘Human Capital Balance 2010–2014’...
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Application of multisine nanoscale impedance microscopy to heterogeneous alloy surface investigations
PublicationIn the recent years atomic force microscopy is recognized as valuable tool for investigation of surficial features of construction materials. It concerns, among other things, studies of changes caused by such phenomena as galvanic corrosion, passivation associated with the growth of oxide layers, or sensitization of austenitic steels with the formation of carbide phases. In addition, atomic forcemicroscopy allows easy coupling...
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Application of different modes of nanoscale impedance microscopy in materials research
PublicationIn recent years, there is noticeable interest in application of various types of scanning probe microscopy in material science research. One of them is contact atomic force microscopy combined with local impedance measurements, known as nanoscale impedance microscopy. Literature references present its application in investigations of new materials, microelectronics diagnostics, or research of protective coatings performance. In...
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The Finite Elements Method application to assesment the impact of turbulence generated by wind turbines on their lacation inclose proximity of overhead high voltage power transmissionlines
PublicationThe paper presents selected aspects of construction of wind turbines location concerning aerodynamic impact on power lines. Reaserch is based on the source data concerning the aerodynamic impact of a wind farm consisting of 8 turbines and 400 kV power line, an analysis of the possibility of wind farm locating in the immediate vicinity of the line was carried out. There are serious problems with locating higher capacity wind farms...
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An innovative approach to the forecasting of energetic effects while wood sawing
PublicationIn the classical approach, energetic effects (cutting forces and cutting power) of wood sawing process are generally calculated on the basis of the specific cutting resistance, which is in the case of wood cutting the function of more or less important factors. On the other hand, the cutting forces (power) problem may be tackled with an innovative, up-to-date fundamental analysis of the mechanics of sawing based on modern fracture...
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An Innovative Approach to the Forecasting of Energetic Effects While Wood Sawing
PublicationIn the classical approach, energetic effects (cutting forces and cutting power) of wood sawing process are generally calculated on the basis of the specifi c cutting resistance, which is in the case of wood cutting the function of more or less important factors. On the other hand, the cutting forces (power) problem may be tackled with an innovative, up-to-date fundamental analysis of the mechanics of sawing based on modern fracture mechanics....
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DESIGN AND STRENGTH CALCULATIONS OF THE TRIPOD SUPPORT STRUCTURE FOR OFFSHORE POWER PLANT
PublicationThe support structure being the object of the analysis presented in the article is Tripod. According to the adopted assumptions, it is a foundation gravitationally set in the water region of 60 m in depth, not fixed to the seabed, which can be used for installing a 7MW wind turbine. Due to the lack of substantial information on designing and strength calculations of such types of structures in the world literature, authors have...
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COVID-19 and digital deprivation in Poland
PublicationResearch background: The problem of digital deprivation is already known, but the COVID-19 pandemic has highlighted its negative consequences. A global change in the way of life, work and socialisation resulting from the epidemic has indicated that a basic level of digital integration is becoming necessary. During the lockdown, people were forced to use ICTs to adapt to a rapidly changing reality. Current experience with coronavirus...
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Mathematical Modeling of Ice Thrusting on the Shore of the Vistula Lagoon (Baltic Sea) and the Proposed Artificial Island
PublicationCoastal lagoons are inland and shallow water bodies, separated from the ocean by a barrier. In cold regions, ice phenomena in shallow water coastal lagoons occur every winter season. Ice is predominantly formed on the surface due to density stratification and surface cooling. The ice dynamics in such areas are dominantly affected by winds. Water dynamics also cause ice movement, but due to the large areal scale of lagoons, the...
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Manufacturing and Recycling Impact on Environmental Life Cycle Assessment of Innovative Wind Power Plant Part 1/2
PublicationWind power plants are considered as ecologically-clean source of energy. However, manufacturing processes cannot be treated that way. Manufacturing processes consume huge amount of electrical and thermal energy and significant amount of materials, e.g. steel, polymers, oils and lubricants. All of the above could be potentially harmful for environment. There are not many works and publications regarding life-cycle analysis of wind...
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The influence of a change in the meniscus cross-sectional shape on the medio-lateral translation of the knee joint and meniscal extrusion
PublicationObjective The purpose of this study was to evaluate the influence of a change in the meniscus cross sectional shape on its position and on the biomechanics of a knee joint. Methods One main finite element model of a left knee joint was created on the basis of MRI images. The model consisted of bones, articular cartilages, menisci and ligaments. Eight variants of this model with an increased or decreased meniscus height were then...
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Toughness augmentation by fibrillation and yielding in nanostructured blends with recycled polyurethane as a modifier
PublicationIn the present paper, we have carefully investigated the morphology and fracture mechanism of the recycled polyurethane (RPU) /epoxy blend system. The second phase (RPU) added to the epoxy resin has a positive effect on the overall mechanical properties. Interestingly, the recycled polymer has a remarkable effect on the fracture toughness of epoxy resin. The mechanism behind the fracture toughness improvement up on the addition...
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Projektowanie zbiornika na nieczystości ciekłe
PublicationW artykule przedstawiono proces projektowania zbiornika podziemnego na nieczystości ciekłe o pojemności ok. 10 m3 posadowionego na gruntach niespoistych (sypkich). Porównano wartości sił wewnętrznych w przypadku skrajnie różnych warunków gruntowych: piasku drobnego o ID = 0,2 oraz żwiru o I D = 0,7. Dodatkowo przeanalizowano wpływ modelu obliczeniowego podłoża na wyniki sił wewnętrznych. Opisano procedurę normową pozwalającą na...
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Application of multi-criteria method to assess the usefulness of a hydrotechnical object for floating housing
PublicationThis publication presents the analysis of three hydrotechnical objects located in the Municipality of Gdańsk with a view of mooring Floating Houses. The assessment of the adaptation of a hydrotechnical object has been carried out by a multi- criteria method AHP and using the main criteria such as: mooring system, communication with the mainland, availability of the utility networks, waste disposal and location of the parking spaces....
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LSTM-based method for LOS/NLOS identification in an indoor environment
PublicationDue to the multipath propagation, harsh indoor environment significantly impacts transmitted signals which may adversely affect the quality of the radiocommunication services, with focus on the real-time ones. This negative effect may be significantly reduced (e.g. resources management and allocation) or compensated (e.g. correction of position estimation in radiolocalisation) by the LOS/NLOS identification algorithm. This paper...
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A Computational Analysis of the Aerodynamic and Aeromechanical Behavior of a Thermo-Well for Steam Temperature Measurement in a Steam Turbine
PublicationThe goal of the paper is twofold: firstly, it presents computational fluid dynamics analysis for finding maximum unsteady flow forces (and their frequencies) acting on a thermo-well for measuring steam temperature in a steam turbine control stage and secondly, it presents computational solid dynamics analysis of possibility of entry into resonance of the thermowell structure. There have been analyzed two cases of flow with changing...
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An influence of the ship's block coefficient implementation on the evaluation of it's hull girder bending
PublicationAn influence of the three different ways of implementation ship's block coefficient δ (three geometrical models) on the stresses due to wave bending moment have been investigated. Two models have been applied and compared: beam one (description of the shape usingparameters) and FEM shell model (direct representation of the shape). The outcomes have been compared to Polish Register of Shipping (PRS) rules. The results show that...
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Shell model of multiple-row moment I-section end-plate joint
PublicationThe paper deals with a problem of application of shell elements in the models of multiple-row moment end-plate connections. The extended connection of I-section with a cross-section W760x265x220 made of steel S355 was analyzed. Comparison analysis of FEM, complex volume and shell models has been done. Three cases with different end-plate thickness: 14, 18 and 36 mm were analyzed and compared with the reference results. Comparison...
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AN INNOVATIVE APPROACH TO PREDICTION ENERGETIC EFFECTS OF WOOD CUTTING PROCESS WITH CIRCULAR-SAW BLADES
PublicationIn the classical approach, energetic effects (cutting forces and cutting power) of wood sawing process are generally calculated on the basis of the specific cutting resistance, which is in the case of wood cutting the function of more or less important factors. The aim of the paper is to present a new calculating model using the application of modern fracture mechanics and to compare cutting parameters of native beech, Bendywood...
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Analiza wyników monitoringu odbieraków prądu w warunkach ruchowych na linii kolejowej
PublicationOmówiono metodę ciągłego monitorowania stanu odbieraków prądu na linii kolejowej w oparciu o pomiar uniesienia przewodów jezdnych sieci trakcyjnej w czasie przejazdu pociągu. Omówiono zasadę działania wdrożonego stanowiska monitoringu. Opisano algorytmy analizy danych pomiarowych - w szczególności oszacowania siły statycznej odbieraka prądu - i przyjęte kryteria oceny odbieraka. W analizie bierze się pod uwagę także prędkość pociągu...
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Study of a Multicriterion Decision-Making Approach to the MQL Turning of AISI 304 Steel Using Hybrid Nanocutting Fluid
PublicationThe enormous use of cutting fluid in machining leads to an increase in machining costs, along with different health hazards. Cutting fluid can be used efficiently using the MQL (minimum quantity lubrication) method, which aids in improving the machining performance. This paper contains multiple responses, namely, force, surface roughness, and temperature, so there arises a need for a multicriteria optimization technique. Therefore,...
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Effective method for determining environmental loads on supporting structures for offshore wind turbines
PublicationThis paper presents a description of an effective method for determining loads due to waves and current acting on the supporting structures of the offshore wind turbines. This method is dedicated to the structures consisting of the cylindrical or conical elements as well as (truncates) pyramids of polygon with a large number of sides (8 or more). The presented computational method is based on the Morison equation, which was originally...
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Effective method for determining environmental loads on supporting structures for offshore wind turbines
PublicationThis paper presents a description of an effective method for determining loads due to waves, current and wind acting on the supporting structures of the offshore wind turbines. This method is dedicated to the structures consisting of the cylindrical or conical elements as well as (truncates) pyramids of polygon with a large number of sides (8 or more). The presented computational method is based on the Morison equation, which was...
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Behaviour of orthotropic surgical implant in hernia repair due to the material orientation and abdomen surface deformation
Publicationrelation to the different range of typical deformations observed in different directions and zones of abdomen surface due to the patients’ life activities, has a significant influence on the extreme junction forces in the mesh–tissue connections and hence the repair persistence. The finite element model of the orthotropic implant was developed, and the junction forces in the connections of tissue and mesh were studied. The kinematical...
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Reliable method of assessing fracture properties of asymmetric bonded joints
PublicationTwo methods of assessing fracture properties of adhesive joints were studied. Two wedge tests: with continuous deflection and with force measurements were compared. Asymmetric geometry of the bonded joint was considered, i.e. two different plates of aluminium alloys: Al-Cu and Al-Mg, were bonded with epoxy DGEBA adhesive. The analytical model is shown to estimate the values of fracture properties: crack position and critical fracture...
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Assessment of copper surface coverage with corrosion inhibitor using AFM-based local electrical measurements
PublicationThe paper presents a new method of assessment of metal surface coverage with corrosion inhibitor and thus of inhibitor protective performance. It is based on the atomic force microscopy measurement performed in a contact mode. Apart from topography images the proposed approach allows acquisition of local DC maps and local electrical impedance spectra via application of DC bias voltage or AC perturbation signal between the conductive...
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Two-criteria optimisation problem for ventral hernia repair
PublicationTwo-criteria optimisation problem related to laparoscopic ventral hernia repair is formulated in this paper. An optimal implant from a given set and its orientation is sought. The implant is subjected to kinematic extortions due to a patient’s body movement and intra-abdominal pressure. The first criterion of the optimisation problem deals with the reaction force in the implant fastener, while the deflection of the implant constitutes...
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Vibration of the bridge under moving singular loads - theoretical formulation and numerical solution
PublicationThe paper presents the results of the numerical analysis of a simple vehicle passing over a simply supported bridge span. The bridge is modelled by a Euler-Bernoulli beam. The vehicle is modelled as a linear, visco-elastic oscillator, moving at a constant speed. The system is described by a set of differential equations of motion and solved numerically using the Runge-Kutta algorithm. The results are compared with the solution...
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Consideration of the safety of bungee jumping in relation to mechanical properties of the instalation based on a jump accident in Gdynia
PublicationThis paper considers a bungee jumping accident that took place in July 2019 in Gdynia, Poland. The authors conducted an investigation to determine the cause of the bungee rope failure. It was based on mechanical tests concerning the strength of the rope as well as the calculation of the force induced in the rope during the jump. Based on the theoretical and experimental results, the rope safety factor was estimated. It appeared...
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Analiza i badania systemu antyspoofingowego GPS
PublicationArtykuł dotyczy problemu spoofingu w systemie GPS, polegającego na niepowołanej transmisji sygnałów imitujących sygnały odbierane z satelitów GPS. Takie działanie prowadzi do wyznaczenia przez odbiornik nawigacyjny nieprawidłowego położenia, prędkości i czasu. Zostały opisane metody przeciwdziałania spoofingowi, w szczególności poprzez przestrzenne przetwarzanie sygnałów. Przedstawiono wyniki badań symulacyjnych efektywności tych...
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The conditions of the business services sector in Poland and its competitiveness in the global market
PublicationThe following article presents the conditions of the business services sector (BSS) in Poland and the assessment of its competitiveness in the global market. The first section discusses the BSS sector and the categories of the provided services, in the division of business process outsourcing, shared services center, information technology outsourcing, research and development. Next the authors presents the status of the business...