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The Imaging of Gdansk Bay Seabed by Using Side Sonar
PublikacjaThis paper is mainly aimed at presentation of an impact of environmental conditions on imaging accuracy by using hydro-acoustic systems in waters of a high non-uniformity of spatial distribution of hydrological parameters. Impact of refraction on erroneous estimation of range, in case of wave radiation into water under a large angle, like in side sonars or multi-beam echo-sounders, is especially important. In this paper seasonal...
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Detection of debonding in reinforced concrete beams using ultrasonic transmission tomography and hybrid ray tracing technique
PublikacjaThis paper concerns inspection of reinforced concrete elements, with particular emphasis on assessing the quality of the adhesive connection between steel and concrete. A novel theoretical model was developed to determine the paths of transmitted, refracted and reflected elastic waves as well as a creeping wave propagated along the inclusion surface. Imaging the internal structure of tested beams was based on wave propagation measurements...
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Experience of hybrid constructed wetlands operation in Gdansk region
PublikacjaThe investigation were carried out at five local hybrid constructed wetlands (HCWs), which secured biological treatment of domestic wastewater generated from 15 to 600 pe. Based on over two years monitoring it was indicated that HCWs ensured very effective removal of organic matter from 74.9 to 95.5 COD % in wild range of loadings (1.5 - 17.0g COD/ m3day). Efficiency of total nitrogen removal varied significantly from 23.4 two...
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Emulsifi ers from renewable materials: an eco-friendly synthesis and properties
PublikacjaThe focus of this study was the preparation of novel bio based polyglycerol emulsifiers characterized by a one pot synthesis, thus by modified properties with respect to interfacial activity and effectiveness as emulsion stabilizers. The final products of the esterification process, carried out in the presence of carboxylates were used directly as emulsifiers (without purification or fractionation). Polyglycerol emulsifiers obtained...
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Sensitivity analysis of simple random beam models by means of Monte Carlo Methods using Variance Reductions Techniques
PublikacjaA probabilistic sensitivity analysis of two nonlinear bar structures is presented. The analysis is carried out on the basis of the Monte Carlo method. The imperfections of the structures and the applied loads are adapted as random variables. Based on all of the generated input variables, an output response of the system is sought. Afterwards, a coefficient responsible for the structure failure is calculated and the limit state...
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Electrochemical oxidation of sulphamerazine at boron-doped diamond electrodes: Influence of boron concentration
PublikacjaThe boron-doped diamond (BDD) electrodes with different boron concentrations have been tested as electrode material for sulphamerazine (SRM) oxidation in water solution. An investigation of the electrode morphology and molecular structure was carried out using high resolution scanning electron microscopy (SEM) and Raman spectroscopy. Electrochemical results showed clearly that the kinetics and efficiency of SRM oxidation were dependent...
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Balance errors in numerical solutions of shallow water equations
PublikacjaThe analysis of the conservative properties of the shallow water equations is presented in the paper. The work focuses on the consistency of numerical solution of these equations with the conservation laws of mass and momentum. The investigations involve two different conservative forms which are solved by an implicit box scheme. The theoretical analysis supported by numerical experiments is carried out for rectangular channel...
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Comparison of the tests for equivalence of the measurement methods for measurement of PM10 dust in ambient air
PublikacjaThe paper presents the motives for conducting the equivalence tests and the reasons of discrepancies between the results of PM10 dust concentration obtained via the reference method and the methods based on 'on-site' measurement. The reference and non-reference methods of measurement of PM10 dust concentration in air have been discussed. Field tests for equivalence, following the Polish standard and the European Union (EU) guidelines,...
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Numerical tests of time-stepping schemes in the context of FEM for 6-field shell dynamics
PublikacjaThe paper deals with integration of dynamic equations of irregular shells performed with relatively long time steps. Numerical instability appearing often in this kind of analysis motivated the authors to present some studies based on numerical tests referring to convergence problems of finite element analysis as well the applied stability conditions. The analysis is carried out on simulations of shell dynamics with the where the...
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Determination of Mechanical Properties of P91 Steel by Means of Magnetic Barkhausen Emission
PublikacjaIn this work, an attempt at determination of mechanical properties by means of a method based on magnetic Barkhausen emission measurements was proposed. The specimens made of P91 steel were subjected to creep or plastic flow which were interrupted after a range of selected time periods in order to achieve specimens with an increasing level of strain. Subsequently, measurements of magnetic Barkhausen emission were carried out, and...
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Acoustic journal bearing - A search for adequate configuration
PublikacjaClassical non-contact bearings are already used in a number of specialist applications but there are somespecialist areas where they cannot be used for variety of reasons and acoustic sliding bearings could be an alternative. The paper presents the quest for a configuration of an acoustic journal bearing and shows that the overall shape of the bearing and its geometry are of a vital importance for the load capacity oft he bearing....
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A COMPARISON OF THE WIND SPECTRUM ACCORDING TO DIFFERENT METHODS - AN ORIGINAL PROJECT OF A BUILDING ON A CLIFF IN GDYNIA
PublikacjaThe article presents numerical simulations of the dynamic wind loads on the structure of a building designed on a cliff in Gdynia. The results obtained from the two methods: Davenport’s and Karman’s are compared. The results allowed a comparison of the two methods, and they provided an answer to the question how a construction, designed in such an unusual condition of a cliff behaves under the influence of the gusting wind. The...
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Research on assessment of bolted joint state using elastic wave propagation
PublikacjaThe work contains results of experimental investigation of elastic wave propagation in a bolted single-lap joint. Tests were carried out for the excitation perpendicular to the connection plane. In experimental studies, PZT transducers were used for both excitation and registration of ultrasonic waves. The analyses took into account varying contact conditions between the elements of the connection depending on the value of the...
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The Pomerania Design Faktory as an Example of 50+ Entrepreneurship Promotion
PublikacjaThe article presents one of the programmes carried out by The Gdańsk Entrepreneurs' Foundation and The Gdansk Labor Office in 2013/14, dedicated to seniors. It is a great example of an innovative project aimed at the activation of individuals aged 50+ by using their own talents and interests in business. It also shows the results of intergenerational cooperation because the trainers — especially the designers — were much younger...
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Acoustics-related aspects of historic interior modernization projects
PublikacjaThe paper presents three historic interiors in which modernization projects have been carried out having an important impact on their acoustic qualities. Two of the described case studies are positive examples of solving the problem of a natural contradictions between modern technical standards and strict discipline imposed by the heritage conservation system. On the other hand, the effect of neglecting the acoustic needs when...
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Efficiency of the Use of LTE System Radio Resources in Highway Transport Enironment
PublikacjaThe paper describes the problem of analysis of throughput-coverage characteristics of the LTE system. Simulation results of the efficiency of the use of LTE radio resources are presented. Simulation studies on the basis of original model of the LTE network simulator were carried out. In addition, the evaluation of throughput for a single connection, and available capacity were evaluated in the context of the use of the same...
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Regional observatory as a part of road safety information system
PublikacjaEU experience clearly indicates that it is necessary to inform and motivate the public on road unsafety to undertake specific preventive efforts, as well as making road users feel responsible for the state of road safety and seek to improve this state gradually to protect their health and life. The implementation of the Warmia-Mazury Road Safety Observatory project will not only be an excellent addition to the activities carried...
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Polypyrrole based gas sensor for ammonia detection
PublikacjaThe nature of polypyrrole response to toxic gases does not allow using the sensor in a conventional way. The main aim of this study is to acquire the information about the concentration using different approaches: a linear approximation, a non-linear approximation and a tangent method. In this paper a two-steps procedure for sensor response measurements has been utilized. Polypyrrole films were electrochemically synthesized on...
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How to deal with knowledge in small companies? Defining emergent KM approach
PublikacjaThis paper examines the concept of emergent KM approach in small companies. The origins of consideration are grounded in the theory of strategic management literature and in particular in the distinction between deliberate versus emergent approach towards strategic planning. Using the methodology of case study, we carried out an explorative research to analyse the characteristics of KM approach in two small companies located in...
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Detection of damages in a rivetted plate
PublikacjaThe paper presents the results of damage detection in a riveted aluminium plate. The detection method has been based on Lamb wave propagation. The plate has been analysed numerically and experimentally. Numerical calculations have been carried out by the use of the time-domain spectral finite element method, while for the experimental analysis laser scanning Doppler vibrometry (LSDV) has been utilised. The panel has been excited...
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GPR simulations for diagnostics of a reinforced concrete beam
PublikacjaThe most popular technique for modelling of an electromagnetic field, the finite difference time domain (FDTD) method, has recently become a popular technique as an interpretation tool for ground penetrating radar (GPR) measurements. The aim of this study is to detect the size and the position of damage in a reinforced concrete beam using GPR maps. Numerical simulations were carried out using the finite differ-ence time domain...
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Shaping of the turnout diverging track with variable curvature sections
PublikacjaThe paper presents an analytical method of shaping the turnout diverging railroad track with variable curvature segments on its length, which in an evident way distinguished it from a typical solution, made up of a single circular arc with no transition curves. Two separate causes including a linear and a nonlinear curvature one in the form of a polynomial have been examined. The obtained solutions of the problem have a universal...
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Numerical simulation of hardening of concrete plate
PublikacjaThe paper presents a theoretical formulation of concrete curing in order to predict temperature evolution and strength development. The model of heat flow is based on a well-known Fourier equation. The numerical solution is implemented by means of the Finite Difference Method. In order to verify the model, the in situ temperature measurements at the top plate of a road bridge were carried out. A high agreement between numerical...
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Lamb wave propagation in a single lap adhesive joint
PublikacjaThe aim of the paper is the analysis of Lamb wave propagation in adhesive joints. The research was performed on a single lap adhesive joint of two steel plates. Two types of joints, namely an intact and with defect were considered. In experimental investigations the condition assessment of the joint was performed with the use of antisymmetric Lamb waves excited by a plate piezo actuators and measured by a laser vibrometer. Numeri-cal...
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Diagnosis of bearing damage in induction motors by instantaneous power analysis
PublikacjaResearch of the machine with simulated bearing damages has been carried out, where variable load torque, simulating bearing damage, was introduced. The results show that components which can be used for bearings diagnosis appear in the spectrum of the product of current and supply voltage instantaneous values. These components are easier to identify than the components of current spectrum, which have been used so far in diagnostic...
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Thermodynamic Cycles of Air Microturbine Power Plants Working on Biomass Fuels
PublikacjaThe gas turbine engine is modified to work as an air turbine set which consists, in the simplest arrangement, of a compressor, a heat exchanger and a turbine. Air is a working medium for both: the compressor and the turbine. This kind of air turbine set can be applied in power plants working on biomass fuels. In this solution we can burn fuels of varying parameters in the external combustion chamber without any harmful effects...
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Underwater acoustic communication system using broadband signal with hyperbolically modulated frequency
PublikacjaThe implementation of reliable acoustic underwater communication in shallow waters is a scientific and engineering challenge, mainly due to the permanent occurrence of the multipath phenomenon. The article presents the concept of a transmission system using a broadband signal with hyperbolically modulated frequency (HFM) to transmit data symbols and synchronize data frames. The simulation tests were carried out in channels with...
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Evaluation of Temperature Influence on Electrochemical Processes Occurring in a Lithium-Ion Supercapacitor with the Use of Dynamic Electrochemical Impedance Spectroscopy
PublikacjaIn order to obtain the full impedance characteristics of a lithium-ion capacitor as a function of temperature, the authors proposed the use of dynamic electrochemical impedance spectroscopy. Impedance tests were carried out under wide range of dynamic temperature changes for lithium-ion supercapacitors. Significant differences in electrochemical processes were observed as a result of working temperature. Moreover, the quality of...
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Monitoring the gas turbine start-up phase on the platform using a hierarchical model based on Multi-Layer Perceptron networks
PublikacjaVery often, the operation of diagnostic systems is related to the evaluation of process functionality, where the diagnostics is carried out using reference models prepared on the basis of the process description in the nominal state. The main goal of the work is to develop a hierarchical gas turbine reference model for the estimation of start-up parameters based on multi-layer perceptron neural networks. A functional decomposition...
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Regional Observatory as a Part of Road Safety Information System
PublikacjaEU experience clearly indicates that it is necessary to inform and motivate the public on road unsafety to undertake specific preventive efforts, as well as making road users feel responsible for the state of road safety and seek to improve this state gradually to protect their health and life. The implementation of the Warmia-Mazury Road Safety Observatory project will not only be an excellent addition to the activities carried...
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Rozmieszczenie wybranych metali ciężkich w ekosystemie oczyszczalni hydrofitowej w Bielkowie.Distribution of heavy metals in ecosystem of free water surface system in Bielkowo.
PublikacjaIn the article the results of investigations of biomass crop and heavy metal contents in bottom sediments and in three species of plants (Glyceria maxima, Typha latifolia)inhabiting a wetland system in Bielkowo, Poland are presented. The measurements were carried out three times during the vegetation season (May, July and October). The contents of metals in different fragments of plants (leaves, stalks and roots) was analyzed....
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Stability of cylindrical steel silos composed of corrugated sheets and columns based on FE analyses versus Eurocode 3 approach
PublikacjaComprehensive static and dynamic 3D stability finite element analyses of a cylindrical steel silo composed of corrugated sheets and open thin-walled vertical stiffener profiles were carried out by taking the geometric and material non-linearity into account. The silowas subjected to axisymmetric and non-axisymmetric loads imposed by a bulk solid following Eurocode 1. Theoretical and measured initial geometric imperfections were...
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Zastosowanie techniki ściegu odpuszczającego do spawania mokrego
PublikacjaW artykule przedstawiono zastosowanie techniki ściegu odpuszczającego do poprawy właściwości złączy ze stali konstrukcyjnych wykonywanych w warunkach mokrego spawania pod wodą. Scharakteryzowano spawanie mokre elektrodami otulonymi zmiany struktury i właściwości złączy spawanych przez nakładanie ściegów odpuszczających. Przedstawiono metodykę oraz wyniki badań metalograficznych i twardości próbek ze stali konstrukcyjnej o podwyższonej...
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Potentiometric Solid-Contact Ion-Selective Electrode for Determination of Thiocyanate in Human Saliva
PublikacjaA new solid-contact potentiometric ion-selective electrode for the determination of SCN− (SCN-ISE) has been described. Synthesized phosphonium derivative of calix[4]arene was used as a charged ionophore. The research included selection of the ion-selective membrane composition, determination of the ISEs metrological parameters and SCN-ISE application for thiocyanate determination in human saliva. Preparation of the ISEs included...
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Impact of digital signal processing on FOC current feedback in high-speed PMSM drive
PublikacjaIn applications where size and weight of the electric motor are among major design concerns, Permanent Magnet Synchronous Motors (PMSMs) with wide operational speed-range are commonly preferred. Due to limited inverter switching frequency, high-speed operation of a drive results in a low ratio between the switching frequency and the fundamental frequency of motor voltage. Such operating conditions have been recently identified...
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Mitigation of the Flow Maldistribution in Minichannel and Minigap Heat Exchangers by Introducing Threshold in the Manifolds
PublikacjaIn the present paper, a detailed numerical investigation has been carried out to analyze the flow maldistribution in 50 parallel rectangular cross-section (1 mm depth and 1 mm width) minichannels and minigap section (1 mm depth and 99 mm width) with rectangular/trapezoidal manifolds in Z-type flow configuration. The author carried out numerical investigation with various mass flowrates, namely 0.05 kg/s, 0.1 kg/s and 0.2 kg/s which...
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Marking the Allophones Boundaries Based on the DTW Algorithm
PublikacjaThe paper presents an approach to marking the boundaries of allophones in the speech signal based on the Dynamic Time Warping (DTW) algorithm. Setting and marking of allophones boundaries in continuous speech is a difficult issue due to the mutual influence of adjacent phonemes on each other. It is this neighborhood on the one hand that creates variants of phonemes that is allophones, and on the other hand it affects that the border...
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Innovative activity of SMEs In Poland
PublikacjaInnovative activity of enterprises is determined by many factors. On one hand, these are external factors creating a sort of innovative climate in the economy, on the other hand - there are many internal factors stimulating or reducing the intensity of innovative activities. What influences the innovativeness of enterprises is the effectiveness of the system supporting innovations, which was stated by for example Pyciński and Żołnierski...
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3-MCPD: A worldwide problem of food chemistry
Publikacja3-MCPD is a heat-induced food contaminant which has been widely investigated for decades. This paper presents an overview of current knowledge about 3-MCPD including its formation routes, occurrence in various foodstuffs, analytical approach, toxicological aspects and future research perspectives. So far 3-MCPD was determined in its free and bound form in thermally-treated foods, edible oils and fats, and infant foods including...
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Developing assumptions for the tram noise attenuation passive system using the noise maps analysis method
PublikacjaThe paper presents experimental research carried out to determine the possible actions to reduce thenoise generated by trams in a highly urbanised area. A few design strategies affecting tram ride qualityhave been presented – especially in the aspect of the acoustic phenomena. Main sources of the noisein trams were characterised. The paper includes selected results of comprehensive...
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Morphometric evaluation of the delayed cerebral arteries response to acetazolamide test in patients with chronic carotid artery stenosis using computed tomography angiography
PublikacjaBackground: The evidence accumulates that the response to acetazolamide test is delayed on the ipsilateral side to stenosis. However, the effect of acetazolamide beyond 30 minutes after acetazolamide administration remains unknown. The aim of this study was to assess the diameters of: anterior cerebral arteries (ACAs), middle cerebral arteries (MCAs) and posterior cerebral arteries (PCAs) before and 60 minutes after the acetazolamide...
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The impact of hydrological research, municipal authorities, and residents on rainwater management in Gdańsk (Poland) in the process of adapting the city to climate change
PublikacjaAim of the study The city of Gdańsk faces changing climatic conditions that result in a higher frequency of extreme weather events. In response to the increasingly frequent appearance of flash floods, scientific research was carried out on changes in the probability of the occurrence of maximum daily precipitation in Gdańsk. The purpose of this paper is to show the role of hydrological research (science), decisions of local authorities...
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Methodology for Carrying Out Measurements of the Tombolo Geomorphic Landform Using Unmanned Aerial and Surface Vehicles near Sopot Pier, Poland
PublikacjaThe human impact on the ecosystem has been particularly evident in the last century; it transforms the Earth’s surface on an unprecedented scale and brings about irreversible changes. One example is an oceanographic phenomenon known as a tombolo, i.e., a narrow belt connecting the mainland with an island lying near the shore formed as a result of sand and gravel being deposited by sea currents. The phenomenon contributes to an...
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The ancient formula of master-apprentice relevance in contemporary architecture education.
PublikacjaThe universalization of the methodology for determining the quality of European higher education exposes the aspect of supporting the student in the education process, which takes the form of tutoring or supervising - a modern form of ancient master-apprentice relationship. The 'master' in architectural education has lawful building qualification and is a member in national architect association - a sine qua non with respect to...
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Impact of probability distribution on the uncertainty of resistance measurement
PublikacjaThe paper presents studies on the influence of probability distributions on the expanded uncertainty of the resistance measurement. Choosing the correct probability distribution is very important to estimate of measurement uncertainty. The paper presents the results of analysis of the resistance measurement uncertainty using the technical method of resistance: 100 G. The analysis of the uncertainty...
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Music signal equalization in a changing environment
PublikacjaThe paper presents the concept of an automatic system for music signal correction, considering room frequency response and music genre being played. The proposed algorithm, based on the room frequency response, compensates acoustic conditions surrounding the sound source. Additionally, the compensation process considers the signal content by recognizing music genre. As part of the described research, a series of subjective tests...
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Numerical investigation on the performance of a small counter-rotating wind turbine
PublikacjaThe article presents the results of the investigation on the performance of a small counter-rotating wind turbine. The wind turbine has been simulated using Computational Fluid Dynamics methods. Actuator Line Model has been successfully used to represent rotors in the computational domain. A parametric study has been carried out, taking into account changes in the tip speed ratio of the rotors while maintaining a constant distance...
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RMS-based damage detection in reinforced concrete beams: numerical simulations
PublikacjaImage-based damage detection methods using guided waves are well known and widely applied approaches in structural diagnostics. They are usually utilized in detection of surface damages or defects of plate-like structures. The article presents results of the study of applicability of imaging wave-based methods in detection in miniscule internal damage in the form of debonding. The investigations were carried out on numerical models...
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Evaluation of the Effectiveness of Methods for Delimitation of the Boundaries of Registered Parcels in the Process of Modernization of Land and Building Registration
PublikacjaIn the article, a comparative analysis of two methods for delimitation of the boundaries of registered parcels was carried out: the method of direct measurement in the field and the photogrammetric method. One of the analyzed factors was the attendance of parcels’ owners during the development of boundary recognition agreements. Research has shown that in this aspect the method of direct measurement...
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Classification of Music Genres by Means of Listening Tests and Decision Algorithms
PublikacjaThe paper compares the results of audio excerpt assignment to a music genre obtained in listening tests and classification by means of decision algorithms. A short review on music description employing music styles and genres is given. Then, assumptions of listening tests to be carried out along with an online survey for assigning audio samples to selected music genres are presented. A framework for music parametrization is created...