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Time Delay Estimation in Two-Phase Flow Investigation Using the γ-Ray Attenuation Technique.
PublicationTime delay estimation is an important research question having many applications in a range of technologies. Measurement of a two-phase flow in a pipeline or an open channel using radioisotopes is an example of such application. For instance, the determination of velocity of dispersed phase in that case is based on estimation of the time delay between two stochastic signals provided by scintillation probes. The proper analysis...
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MODERNIST, 1920S AND 1930S INDUSTRIAL ARCHITECTURE OF THE PORT OF GDYNIA - IN SEARCH OF AN AESTHETIC LANGUAGE FOR UTILITARIAN BUILDINGS OF THE POLISH GATEWAY TO THE WORLD
PublicationThe purpose of the article is to present the results of the research on the aspects of the Port of Gdynia modernist architecture aesthetics. Its construction was one of the two major projects carried out in the interwar period in Poland. In the course of analyses it has been attempted to answer the question whether an individual aesthetic language has been created in the 1920s and 1930s for the industrial architecture of the Polish...
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THE THERMODYNAMIC ANALYSIS OF THE SZEWALSKI HIERARCHIC VAPOUR CYCLE COOPERATED WITH THE SYSTEM OF HEAT RECOVERY
PublicationIn this paper, thermodynamic analysis of the Szewalski hierarchic vapour cycle cooperated with the system of heat recovery from exhaust gases are presented. According to that purpose, the CFM (Computation Flow Mechanics [1,3]) approach has correctly been used. The whole system consists of the first traditional steam cycle, the second organic Rankine cycle (ORC) and system of heat recovery with use of water with temperature 90...
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Experimental study on the effectiveness of polymer damper in damage reduction of temporary steel grandstand
PublicationA large number of accidents, involving collapses of temporary grandstands during different types of events, were observed in the past. If the synchronized movement of people is tuned with the natural frequency of the affected part of the structure, resonance might occur. It may lead to severe damages of grandstands, their collapse or panic among the spectators. The aim of the paper is to assess, through preliminary experimental...
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A comparative analysis of the effectiveness of corporate bankruptcy prediction models based on financial ratios: Evidence from Colombia, 2008 to 2015
PublicationLogit and discriminant analyses have been used for corporate bankruptcy prediction in several studies since the last century. In recent years there have been dozens of studies comparing the several models available, including the ones mentioned above and also probit, artificial neural networks, support vector machines, among others. For the first time for Colombia, this paper presents a comparative analysis of the effectiveness...
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Numerical Solution of the Two-Dimensional Richards Equation Using Alternate Splitting Methods for Dimensional Decomposition
PublicationResearch on seepage flow in the vadose zone has largely been driven by engineering and environmental problems affecting many fields of geotechnics, hydrology, and agricultural science. Mathematical modeling of the subsurface flow under unsaturated conditions is an essential part of water resource management and planning. In order to determine such subsurface flow, the two-dimensional (2D) Richards equation can be used. However,...
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The In-Depth Studies of Pulsed UV Laser-Modified TiO2 Nanotubes: The Influence of Geometry, Crystallinity, and Processing Parameters
PublicationThe laser processing of the titania nanotubes has been investigated in terms of morphology, structure, and optical properties of the obtained material. The length of the nanotubes and crystallinity, as well as the atmosphere of the laser treatment, were taken into account. The degree of changes of the initial geometry of nanotubes were checked by means of scanning electron microscopy, which visualizes both the surface and the cross-section....
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A Proposed Machine Learning Model for Forecasting Impact of Traffic-Induced Vibrations on Buildings
PublicationTraffic-induced vibrations may cause various damages to buildings located near the road, including cracking of plaster, cracks in load-bearing elements or even collapse of the whole structure. Measurements of vibrations of real buildings are costly and laborious. Therefore the aim of the research is to propose the original numerical algorithm which allows us to predict, with high probability, the nega-tive dynamic impact of traffic-induced...
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Corrosion fatigue crack propagation rate characteristics for weldable ship and offshore steels with regard to the influence of loading frequency and seawater temperature
PublicationAfter Vosikovsky (1975), the corrosion fatigue crack growth rate (CFCGR) characteristics have been divided into three regions. The region-III rates are very close to mechanical fatigue crack growth rates. CFCGR formulae, including the long-crack length effect (in region I only), the loading frequency effect (in region II only), and the saltwater temperature effect, have been proposed. It has been assumed that CFCGR is proportional...
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The use of thermal imaging camera to estimate velocity profiles based on temperature distribution in a free convection boundary layer
PublicationThis work describes an attempt to assess whether the temperature field from a thermal imaging camera can be converted into a velocity field with an accuracy sufficient for qualitative conducting or describing the phenomenon, i.e. when the Navier-Stokes, Fourier-Kirchhoff and continuity equations are mutually coupled. The consequence of this link between temperature fields and velocity is the possibility to formulate the hypothesis...
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Highly stable CsFAPbIBr perovskite solar cells with dominant bulk recombination at real operating temperatures
PublicationMixed-cation mixed-halide perovskite solar cells have been characterized in DC at different temperatures (from −20 °C up to 50 °C) and the time evolution of the device efficiency has been assessed using different degradation protocols (indoors and outdoors). The completely planar p–i–n structure is ITO/CuNiOx/PTAA/CsFAPbIBr/PCBM/PEI/Ag. Pristine current–voltage characteristics barely show hysteresis, at any temperature. Open circuit...
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Innovative Bidirectional Isolated High-Power Density On-Board Charge for Vehicle-to-Grid
PublicationThis paper deals with developing and implementing a bidirectional galvanically isolated on-board charger of a high-power density. The power density of the new charger was 4 kW/kg and 2.46 kW/dm3, and the maximum efficiency was 96.4% at 3.4 kW. Due to the requirement to achieve a high-power density, a single-stage inverter topology was used. Regarding switching losses, due to the topology of the circuit with so-called hard switching,...
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Numerical analysis of CO2-water separation in a horizontal double T-junction
PublicationCarbon dioxide is considered one of the main factors leading to global warming. Considering the significant impacts of CO2 on climate change, various technologies have been developed in recent decades to control carbon emission, such as for example CO2 capture and storage. The developed cycle of a negative CO2 emission power plant includes some devices, out of which, separator plays an indispensable role. To this end, T-junction...
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The Motion Analysis of Attacus Atlas Rigid Wing
PublicationThe remarkable aerodynamic efficiency of flapping insect wings has fascinated researchers for many years. Butterfly wings are distinguished by a much larger lifting surface, and thus, a different style of flapping flight. The considerations described in the article are an introduction to a fully flexible analysis of the wing in motion. The study of the rigid wing gives the basic knowledge necessary in the further process. The yaw,...
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Integrated model for the fast assessment of flood volume: Modelling – management, uncertainty and sensitivity analysis
PublicationThe specific flood volume is an important criterion for assessing the performance of sewage networks. It has been shown that its value is greatly influenced by the layout of the sewers in the catchment area, which is usually expressed by a fractal dimension. Currently, only mechanistic models (such as SWMM) enable the determination of the impact of the layout of the sewers on flooding volume, but they require additional and robust...
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The analysis of tram tracks geometrical layout based on Mobile Satellite Measurements
PublicationIn this article, the results of the research in a field of which uses active global navigation satellite system (GNSS) geodetic networks for the inventory of geodetic geometric tram tracks are presented. The applied measurement technique has been adapted for the designing of the geometric layout of tram tracks. Several configurations of receivers and settings of an active GNSS networks with the objective to increase the accuracy...
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Review on mechanisms and efficiency of removal of microbiological contaminants in constructed wetlands
PublicationConstructed wetlands (CW) have been considered as a waste and a stormwater treatment systems for small communities or for areas with unsteady sewage flow conditions. Several investigations were undertaken for estimation suspended solids, organic matter and nutrients efficiency removal but only few focused on retention of microorganisms in constructed wetlands. In this review mechanisms of elimination of viruses, indicator bacteria...
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The use of constructed wetlands for the treatment of industrial wastewater
PublicationConstructed wetlands are characterized by specific conditions enabling simultaneous various physical and biochemical processes. This is the result of specific environment for the growth of microorganisms and hydro-phytes (aquatic and semiaquatic plants) which are capable of living in aerobic, anaerobic and facultative anaerobic conditions. Their interaction contributes to the intensification of oxidation and reduction responsible...
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Waste materials assessment for phosphorus adsorption toward sustainable application in circular economy
PublicationPhosphorus is the main determinant of nutrient enrichment in the water bodies. Many resources including nutrients may be shortly exhausted, assuming current consumption. This scenario leads to growing interest in resources recovery and/or reuse, which together with sustainable energy consumption and waste reduction are the main courses of the circular economy. Usage of coagulants in wastewater treatment plants (WWTP) does not allow...
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Cyfrowy akcelerator wybranych modułów standardu kompresji wideo H.264
PublicationW artykule przedstawiono konfigurowalny cyfrowy akcelerator estymacji ruchu przeznaczony dla enkodera wideo standardu H.264. Akcelerator został zaimplementowany w technologii FPGA oraz w układzie ASIC w technologii UMC 90 nm. Obie implementacje zostały zweryfikowane, a szczegółowe wyniki pomiarów akceleratora ASIC zostały porównane z innymi dostępnymi w literaturze propozycjami. System został zoptymalizowany do współpracy z oprogramowaniem...
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Inteligentne systemy agentowe w systemach zdalnego nauczania
PublicationW pracy omówiono inteligentne systemy agentowe w systemach zdalnego nauczania. Po krótkim przedstawieniu ewolucji systemów zdalnego nauczania i ich wybranych zastosowań, scharakteryzowano inteligentne agenty edukacyjne. Omówiono wykorzystanie programowania genetycznego oraz algorytmów neuro-ewolucyjnych do implementacji oprogramowania tej klasy. Ponadto, nawiązano do modelu Map-Reduce, który efektywnie wspiera architekturę nowoczesnego...
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CROSS SECTIONS CALCULATIONS FOR ELECTRON SCATTERING FROM RHODANINE AND CYANOACETIC ACID
PublicationCross sections for electron-impact ionization and for elastic electron scattering for rhodanine (C3H3NOS2) and cyanoacetic acid (C3H3NO2) have been calculated in wide impinging electron energy range.
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Wind Conditions in Urban Layout – Numerical and Experimental Research
PublicationThis paper presents research which compares the numerical and the experimental results for different cases of airflow around a few urban layouts. The study is concerned mostly with the analysis of parameters, such as pressure and velocity fields, which are essential in the building industry. Numerical simulations have been performed by the commercial software Fluent, with the use of a few different turbulence models, including...
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Dissociation energies of protonated water clusters
PublicationRelative abundances of positively ionized water clusters formed in a low-pressure electrical discharge as function of reduced electric field were obtained by using drift cell and quadrupole mass spectrometer. It was noticed that some clusters say with n = 4 were more abundant than others, at comparable drift conditions. Dissociation energies have been derived from equilibrium conditions for relative clusters abundances. The Hartree-Fock...
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The consequences of applying a new Polish Water Law Act for protection against urban flooding
PublicationPrevious legal regulations did not create conditions for a comprehensive solution to the problems of the urban melioration complex. For over 20 years, urban flooding caused by atmospheric precipitation has been systematically recurring in Poland. The article was elaborated on the experience resulting from the 2001 and 2016 floods in Gdansk (Poland). The newly adopted Water Law Act creates a foundation for a systemic solution...
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The role and importance of WIMAX mobile system as a high-performance data transfer technology in wireless sensor networks for wide area monitoring applications
PublicationThe study discuses basic features and functional design of WiMAX Mobile system, based on the IEEE 802.16e (Release 1.5 Rev. 2.0) standard. The analysis has been made in terms of ability to use this system to transmit video stream related to monitoringof large agglomeration areas. What is more, the study includes comparison of technical parameters of WiMAX Mobile system with competitive systems such as: HSPA+ and UMTS-LTE, which...
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Context Search Algorithm for Lexical Knowledge Acquisition
PublicationA Context Search algorithm used for lexical knowledge acquisition is presented. Knowledge representation based on psycholinguistic theories of cognitive processes allows for implementation of a computational model of semantic memory in the form of semantic network. A knowledge acquisition using supervised dialog templates have been performed in a word game designed to guess the concept a human user is thinking about. The game,...
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Preliminary typology and contextual analysis of Roman and late antique cooking wares from the Roman rural settlement at Podšilo bay on the island of Rab (north–eastern Adriatic, Croatia)
PublicationThe paper presents a preliminary typology of coarse cooking ware from the Roman/late antique layers of the rural settlement at Podšilo bay on the island of Rab. The vessels have been associated with several basic shapes and divided by types, while fabrics have been described macroscopically. Analogies and a contextual analysis were used to propose dating and to assess provenience for well-known ware classes or to define areas...
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Application of dynamic time warping and cepstrograms to text-dependent speaker verification
PublicationThis work provides a description of an automatic speaker verification (ASV) system. In particular, it documents the evolution of all individual stages of the proposed ASV system design from the phase of preprocessing to an operational decision making system. The aim of this research was to achieve the system of the best safety and ease of use in view of users. The objective estimation of this target has been accomplished by assessing...
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Chromogenic macrocyclic derivatives of azoles - synthesis and properties,
PublicationNew azocrown ethers comprising imidazoles in the macrocycle have been synthesized. Imidazole, 2-methyl-, 4-methyl-, and 4-phenylimidazole were incorporated to form macrocyclic units by coupling with the appropriate bis-diazonium salts. The syntheseswere performed under high dilution conditions. The X-ray structure of a water adduct of the 21-membered crown ether derivative of 4-methylimidazole 8 has been solved. Metal...
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Azomacrocyclic derivatives of imidazole: synthesis, structure, and metal ion complexation properties
PublicationNew azocrown ethers comprising imidazoles in the macrocycle have been synthesized. Imidazole, 2-methyl-, 4-methyl-, and 4-phenylimidazole were incorporated to form macrocyclic units by coupling with the appropriate bis-diazonium salts. The syntheseswere performed under high dilution conditions. The X-ray structure of a water adduct of the 21-membered crown ether derivative of 4-methylimidazole 8 has been solved. Metal...
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A 0.5-V bulk-driven voltage follower / DC level shifter and its application in class AB output stage
PublicationA simple realization of a 0.5-V bulk-driven voltage follower/DC level shifter, designed in a 0.18um CMOS technology is presented in the paper. The circuit is characterized by large input and output voltage swings, and a DC voltage gain close to unity. The DC voltage shift between input and output terminals can be regulated in a certain interval around zero, by means of biasing current sinks. An application of the proposed voltage...
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Properties comparison of rubber and three layer PTFE-NBR-bronze water lubricated bearings with lubricating grooves along full bush circumference based on experimental tests
PublicationWater lubricated bearings have been in industrial use for well over a century. During the last decade their traditional range has been expanded with new, modern products. Despite that fact, certain solutions continue to employ the standard rubber bearing with lubricating grooves located along entire bush circumference. The work presents experimental research conducted on comparable sliding bearings with lubrication grooves along...
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Electromagnetic interference frequencies prediction model of flyback converter for snubber design
PublicationSnubber design for flyback converters usually requires experimental prototype measurements or simulation based on accurate and complex models. In this study simplified circuit modelling of a flyback converter has been described to dimension snubbers in early stage of design process. Simulation based prediction of the transistor and diode ringing frequencies has been validated by measurements in a prototype setup. In that way obtained...
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Experimental investigation of forced convection of water/EGAl2O3 nanofluids inside horizontal tube
PublicationIn this paper, forced convection of water/EG-Al2O3 nanofluids inside horizontal stainless steel tube is studied experimentally. As base fluid served water/EG mixture of two ratios (60:50 and 50:50). Nanoparticle mass concentrations was 0.1% or and 1%. Transition and turbulent flow regimes were tested. Average heat transfer coefficient and pressure drop values were determined for nanofluids and compared to base fluids. Deterioration...
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The difficult heritage. The reuse of former prison buildings
PublicationIn recent years, there has been a trend to reuse abandoned buildings. Adaptive re-use allows preservation of the original structure and implements a new function to it. Such activity could help to preserve the historic value of buildings; moreover, many other advantages can be found in educational, ecological and economic fields. However, the question arises of whether every object can be freely adapted. This article examines the...
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Trim Optimisation - Theory and Practice
PublicationForce Technology has been working intensively with trim optimisation tests for almost last 10 years. Focus has primarily been put on the possible power savings and exhaust gases reduction. This paper describes the trim optimisation process for a large cargo vessel. The physics behind changed propulsive power is described and the analyses in order to elaborate the optimum trimmed conditions are presented. Different methods for prediction...
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Convergence of rational multistep methods of of Adams-Padé type
PublicationRational generalizations of multistep schemes, where the linear stiff part of a given problem is treated by an A-stable rational approximation, have been proposed by several authors, but a reasonable convergence analysis for stiff problems has not been provided so far. In this paper we directly relate this approach to exponential multistep methods, a subclass of the increasingly popular class of exponential integrators. This natural,...
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Modification of Selected Propagation Models in Terms of Path Loss Estimation in Container Terminal
PublicationIt is particularly important to look for any propagation model that could be useful for designing mobile radio networks in container terminal environment. Selected propagation models have been investigated. Firstly - basing on measurements results - they have been evaluated in this scope and the analysis has shown, that the adjustment is needed. This modification improved significantly the accuracy of path loss modelling. For the...
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Damage localisation in a stiffened plate structure using a propagating wave
PublicationThe paper presents an application of changes in propagating waves for damage detection in a stiffened aluminium plate. The experimental investigation was conducted on an aluminium plate with riveted two L-shape stiffeners. The wave has been excited with a piezoelectric transducer and measured with the Laser Scanning Doppler Vibrometer. Recorded signals were analysed using the special signal processing techniques developed for damage...
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Speace frienly for the blind = Przestrzeń przyjazna dla niewidomych
PublicationThe article presents issues connected with accessibility of public space for people with eyesight disabilities. The use of the extravisual spatial stimuli in shaping the urban environment has been analysed. Spaces in which musltisensory spatial reception is feasible become user-friendly, as they come to meet the changing needs of their users. The article introduces a system of textures aiding spatial orientation, navigation and...
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Control design for slow speed positioning
PublicationThe problem under study is a synthesis of position and heading control system for low frequency model of surface vessel described by 3 DOF mathematical model. The recursive vectorial backstepping control design was used to keep fixed position and heading in presence of wave disturbances. The controller has been simulated on computer model of scaled supply vessel. It has been assumed that the actuators produce generalized forces...
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Evaluation of working spaces' technical condition of marine diesel engine on the basis of operation research
PublicationThe paper presents the method of evaluation of the technical state of working spaces of a marine diesel engine at the reduced control susceptibility. The method foresees making diagnosis on the basis of the measurements of exhaust gas pressure in the channels connecting engine cylinders with turbocharger's turbine. In the beginning of the article the research objects are characterized i.e. ZVIEZDA main engine of M401 type and the...
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Modal analysis of cylindrical steel tanks
PublicationCylindrical steel tanks are very popular structures used for storage of products of chemical and petroleum industries. Their safety and reliability is crucial because any failure could have serious consequences. The aim of present paper is to show the results of the first phase of investigation of seismic behaviour such structures. Modal analysis using Finite Element Method (FEM) for three models of real tanks used in Poland has...
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Modelling of joining route segments of differential curvature
PublicationThe paper presents a new general method of modelling route segments curvature using differential equations. The method enables joining of route segments of different curvature. Transitional curves of linear and nonlinear curvatures have been identified in the case of joining two circular arcs by S-shaped and C-oval transitions. The obtained S-shaped curves have been compared to the cubic C-Bezier curves and to the Pythagorean hodograph...
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Optical Spectroscopic Studies of Tetrahydrofuran Fragmentation Induced by Collisions with Dihydrogen Cations
PublicationCollisions of dihydrogen cations with tetrahydrofuran molecules have been studied. Luminescence spectra and the emission functions of the excited products at projectile energies ranging from 8 to 1000 eV have been measured using collision-induced emission spectroscopy. The recorded spectra are dominated by the atomic lines of the hydrogen Balmer series, whose intensities decrease more quickly than derived by the quantum-theoretical...
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Application of deep eutectic solvents (DES) in analytical chemistry
PublicationRecent years have been associated with efforts to reduce the impact on the natural environment. A greener approach has been introduced in various areas of science, including analytical chemistry. One of the basic procedures for preparing a sample for analysis is its extraction. Traditional methods involve the use of large amounts of organic compounds, often toxic, with an unfavorable impact on the environment. A representative...
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UWB-Based Indoor Navigation in a Flexible Manufacturing System Using a Custom Quadrotor UAV
PublicationA novel solution for indoor navigation of a transportation drone in flexible manufacturing is presented in this paper. To address the challenges of accurate and robust drone navigation in occluded environments, an ultra-wideband (UWB) navigation system has been integrated with a commercially available open source control platform. The system offers high accuracy (± 20 mm), low power consumption, resistance to electronic interference,...
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Analiza spostrzeżeń podczas audytów w przedsiębiorstwach z branży spożywczej
PublicationAnalizowano dane z 54 przedsiębiorstw potwierdzających zgodność z wdrożonym systemem ISO 22000 w latach 2005–2013 przez jednostkę certyfikującą DNV GL–BA. Przedstawiono najczęściej spotykane kategorie niezgodności stwierdzane podczas audytów certyfikujących w przedsiębiorstwach należących do łańcucha żywnościowego. Przeanalizowano występujące problemy wpływające na bezpieczeństwo żywności podczas procesu produkcyjnego. Obliczono...
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Wordventure - Developing WordNet in Wikipedia-like Style
PublicationThe article describes an approach for building WordNet semantic dictionary in a collaborative way. The idea of gathering lexical data has been proposed, as well as the system for linguistic data acquisition and management.