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Search results for: FLOATING-POINT ARITHMETIC
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Size-exclusion chromatography for the determination of the boiling point distribution of high-boiling petroleum fractions
PublicationThe paper describes a new procedure for the determination of boiling point distribution of high-boiling petroleum fractions using size exclusion chromatography with refractive index detector. Thus far, the determination of boiling range distribution by chromatography has been accomplished using simulated distillation with gas chromatography with the flame ionization detection. This study revealed that in spite of substantial differences...
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Model of heat transfer in the stagnation point of rapidly evaporating microjet
PublicationThe paper presents investigation into the single water microjet surface cooling producing evaporating film. Reported tests were conducted under steady state conditions. Experiments were conducted using the nozzle size of 70 and 100 mikrometer respectively. In the course of investigations obtained were experimental relations between heat flux and wall superheating. It was proved that the phenomenon is similar to that of pool boiling...
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Fixed Point Theory and Applications
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Multilevel inverter neutral-point voltage sensor diagnostic based on the Extended Kalman Filter
PublicationA new algorithm for neutral point voltage imbalance estimation in DC link of the three-level (3L) neutral point clamped (NPC) voltage source inverter (VSI) is proposed. Application of the proposed algorithm does not require any additional sensors. The unbalanced voltage calculation is based on the information derived from the inverter output measured currents and from the knowledge of the load model parameters. In order to estimate...
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Postquarter-Point Case of Ship’s Side-Berthing and Its Influence on Marine Fender Pitch
PublicationThis paper presents a critical analysis of some selected codes and practical recommendations used as basic rules in the design procedures of modern marine fender systems. The first part of the discussion pertains to the existing equations used in calculating the eccentricity coefficient in the ship’s kinetic energy equation and the maximum allowable fender pitch (spacing) in a set of fenders installed along a quay wall. A new approach...
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From a Point Cloud to a 3D Model - an Exercise for Users of AutoCAD and Revit
PublicationThe paper presents a proposal of the topic of an exercise for students of building faculties as part of classes on 3D modelling. The task consists in creating a three-dimensional model based on the measurement obtained with the Leica P30 laser scanner. Due to the maximum number of points in the cloud in the presented programs, the output files must be properly cleared and reduced. The point cloud was pre-processed in Cyclone software....
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Methods for quality improvement of multibeam and LiDAR point cloud data in the context of 3D surface reconstruction
PublicationPoint cloud dataset is the transitional data model used in several marine and land remote-sensing applications. During further steps of processing, the transformation of point cloud spatial data to more complex models containing higher order geometric structures like edges and facets may be possible, if an appropriate quality level of input data is provided. Point cloud datasets usually contain a considerable amount of undesirable...
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State equations in the mathematical model of dynamic behaviour of multihull floating unit
PublicationPrzedstawiony artykuł dotyczy dynamiki wielokadłubowej jednostki pływającej typu katamaran poddanej wymuszeniom pochodzącym od falowania nieregularnego. Analiza dynamiki jednostki wielokadłubowej została przeprowadzona przy założeniu, że model układu jest modelem liniowym na który działa fala nieregularna. Model matematyczny takiego układu dynamicznego jest reprezentowany poprzez równania stanu. Zapisane zostały równania uwzględniające...
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Preliminary analysis of proposed ship docking systems for a designed floating dock
PublicationW artykule przedstawiono alternatywne koncepcje, wraz z ich analizą porównawczą, urządzeń dokujących statek na doku pływającym. Dok ten projektowany był na Wydziale Oceanotechniki i Okrętownictwa Politechniki Gdańskiej w ramach projektu ECOLOGICAL DOCK E!2968. Zaprezentowane rozwiązania różnią się głównie rodzajem zastosowanych w nich urządzeń: w pierwszym przypadku są to przewijarki i wózki dokujące, zaś w drugim - wciągarki...
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Protection of Earthing Reactor Connected to the Star Point of a High Voltage Shunt Reactor
PublicationThe article presents the problem of protection of earthing reactors connected to the star point of shunt reactors in high voltage lines, with particular regard to the detection of internal faults. Model analyses for an actual system commissioned in 2015, which is intended to be provided with earthing reactors, are included.
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Processing of LiDAR and Multibeam Sonar Point Cloud Data for 3D Surface and Object Shape Reconstruction
PublicationUnorganised point cloud dataset, as a transitional data model in several applications, usually contains a considerable amount of undesirable irregularities, such as strong variability of local point density, missing data, overlapping points and noise caused by scattering characteristics of the environment. For these reasons, further processing of such data, e.g. for construction of higher order geometric models of the topography...
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Fractional neutron point kinetics equations for nuclear reactor dynamics – Numerical solution investigations
PublicationThis paper presents results concerning numerical solutions to a fractional neutron point kinetics model for a nuclear reactor. The paper discusses and expands on results presented in (Espinosa-Paredes et al., 2011). The fractional neutron point kinetics model with six groups of delayed neutron precursors was developed and a numerical solution using the Edwards’ method was proposed (Edwards et al., 2002). The mathematical model...
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Assessing historical church tower asymmetry using point cloud spatial expansion
PublicationChurch towers are key cultural heritage. In theory, towers are vertical, while facade elements are symmetrically positioned around the tower axis. However, during service of a structure, building and lifetime conditions cause deviations, with associated risks. Laser scanning point clouds can be used to assess the structural state but a universal approach was missing. The proposed algorithm first estimates the tower inclination,...
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Photovoltaic Maximum Power Point Technique based on Incremental Conductance (INCON) control algorithm
PublicationMaximum output power status can significantly improve the deployment rate of solar energy system. In order to get the maximum power output, issue of tracking maximum power point (MPP), reduced harmonics around MPP and improve efficiency of the solar power energy system, this paper presents the improved maximum power point tracking (MPPT) control...
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A Cost-Effective Method for Reconstructing City-Building 3D Models from Sparse Lidar Point Clouds
PublicationThe recent popularization of airborne lidar scanners has provided a steady source of point cloud datasets containing the altitudes of bare earth surface and vegetation features as well as man-made structures. In contrast to terrestrial lidar, which produces dense point clouds of small areas, airborne laser sensors usually deliver sparse datasets that cover large municipalities. The latter are very useful in constructing digital...
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Evaluation of the Combination of Muscle Energy Technique and Trigger Point Therapy in Asymptomatic Individuals with a Latent Trigger Point
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Reliability Analysis of Sea Cliff Slope Stability by Point Estimate Method
PublicationThe paper presents a reliability analysis of a sea cliff slope. The cliff, located in Jastrzębia Góra, is characterised by a complicated geological structure. Although currently stable, it is in fact close to the limit state. The objective of this paper is to present the point estimate method (PEM) of determining the mean value and standard deviation of the safety factor of the slope. Assuming its normal distribution, these statistical...
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Reliability Analysis of Sea Cliff Slope Stability by Point Estimate Method
PublicationThe paper presents a reliability analysis of a sea cliff slope. The cliff, located in Jastrzębia Góra, is characterised by a complicated geological structure. Although currently stable, it is in fact close to the limit state. The objective of this paper is to present the point estimate method (PEM) of determining the mean value and standard deviation of the safety factor of the slope. Assuming its normal distribution, these statistical...
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Emilia Miszewska dr inż.
PeopleEmilia Miszewska was born in 1986 in Gdańsk. She graduated from Primary School No. 17 in Gdańsk with sports classes specializing in swimming and Janusz Kusociński Sports Secondary School No. 11 in Gdańsk. In 2005, she started uniform master's studies at the Faculty of Civil and Environmental Engineering, which she completed in 2011, defending her diploma thesis entitled "Analysis and development of fire protection guidelines and...
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Classification of objects in the LIDAR point clouds using Deep Neural Networks based on the PointNet model
PublicationThis work attempts to meet the challenges associated with the classification of LIDAR point clouds by means of deep learning. In addition to achieving high accuracy, the designed system should allow the classification of point clouds covering an area of several dozen square kilometers within a reasonable time interval. Therefore, it must be characterized by fast processing and efficient use of memory. Thus, the most popular approaches...
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Numerical solution analysis of fractional point kinetics and heat exchange in nuclear reactor
PublicationThe paper presents the neutron point kinetics and heat exchange models for the nuclear reactor. The models consist of a nonlinear system of fractional ordinary differential and algebraic equations. Two numerical algorithms are used to solve them. The first algorithm is application of discrete Grünwald-Letnikov definition of the fractional derivative in the model. The second involves building an analog scheme in the FOMCON Toolbox...
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Deformation Analysis of a Composite Bridge during Proof Loading Using Point Cloud Processing
PublicationRemote sensing in structural diagnostics has recently been gaining attention. These techniques allow the creation of three-dimensional projections of the measured objects, and are relatively easy to use. One of the most popular branches of remote sensing is terrestrial laser scanning. Laser scanners are fast and efficient, gathering up to one million points per second. However, the weakness of terrestrial laser scanning is the...
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Nonlinear planar modeling of massive taut strings travelled by a force-driven point-mass
PublicationThe planar response of horizontal massive taut strings, travelled by a heavy point-mass, either driven by an assigned force, or moving with an assigned law, is studied. A kinematically exact model is derived for the free boundary problem via a variational approach, accounting for the singularity in the slope of the deflected string. Reactive forces exchanged between the point-mass and the string are taken into account via Lagrange...
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Developing Methodology for Model Tests of Floating Platforms in Low -Depth Towing Tank
PublicationThe paper presents two different methods of physical modeling of semi-submersible platform mooring system for research in low depth towing tank. The tested model was made in the scale of 1:100 resembling the "Thunder Horse" platform moored in the Gulf of Mexico at a depth of 1,920 m. Its mooring system consisted of 16 semi-taut mooring lines (chain-wire-chain) spaced starshape and attached at the bottom to suction piles. The tests...
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Possibility to use engine compression ignition engines in floating power plants marine
PublicationCompression-ignition engines used in ship technology as main propulsion engines are large units reaching even to 50-60 MW. The engines can be used in power industry for electricity generation in a simple or combined steam turbine system in combined heat and power plants. The leading engine in such an arrangement is an internal-combustion piston engine. The main propulsion engines are used in large piston internal-combustion engines...
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Developing a methodology for model tests of floating platforms in a towing tank of low depth
PublicationThe paper presents two ways to mooring model of semi-submersible platform for research in the small depth towing pool. The tested model was made in the likeness of 1:100 Thunder Horse platform moored in the Gulf of Mexico at a depth of 1,920 m. Its mooring system consisted of 16 semi-taut mooring lines (chain-wire-chain) spaced Star-shape and attached at the bottom to the suction piles. The tests were performed in the towing pool...
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Probabilistic concept of defining the situations possible to occur during operation of floating docks
PublicationW artykule zasygnalizowana została możliwość oszacowania bezpieczeństwa doków pływajacych, w wyniku zastosowania teorii procesów semimarkowskich, zarówno w fazie projektowania jak też eksploatacji. Przedstawiono opis formalny sytuacji, jakie mogą zaistnieć podczas funkcjonowania (działania) doków pływających, zarówno budowlanych jak również remontowych. Wyróżniono takie sytuacje jak: normalna, skomplikowana, niebezpieczna, awaryjna...
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Pipelined division of signed numbers with the use of residue arithmetic for small number range with the programmable gate array
PublicationIn this work an architecture of the pipelined signed residue divider for the small number range is presented. Its operation is based on reciprocal calculation and multiplication by the dividend. The divisor in the signed binary form is used to compute the approximated reciprocal in the residue form by the table look-up. In order to limit the look-up table address an algorithm based on segmentation of the divisor into two segments...
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Optimization algorithm and filtration using the adaptive TIN model at the stage of initial processing of the ALS point cloud
PublicationAirborne laser scanning (ALS) provides survey results in the form of a point cloud. The ALS point cloud is a source of data used primarily for constructing a digital terrain model (DTM). To generate a DTM, the set of ALS observations must be first subjected to the point cloud processing methodology. A standard methodology is composed of the following stages: acquisition of the ALS data, initial processing (including filtration),...
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On the Nielsen fixed point theory for multivalued mappings
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Fixed point indices of iterated planar maps
PublicationW artykule dokonuje się przeglądu wyników dotyczących indeksów punktu stałego iteracji odwzorowań planarnych, sformułowane zostają otwarte pytania i podane nowe dowody w przypadku gładkim.
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The point forecast of the situation of the examined company on the market
PublicationOkreślono sytuację badanego przedsiębiorstwa na rynku za pomocą analizy portfolio, w aspektach wzrostu rynku oraz względnego udziału badanego przedsiębiorstwa w rynku. Analiza objęła zarówno okres retrospektywny jak i prognozowany.
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Fixed point indices of iterations of planar homeomorphisms.
PublicationW pracy bada się postać indeksów iteracji lokalnych homeomorfizmów płaszczyzny.
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A general concept of design procedure for floating docks regarding their reliability, safety and ecological aspects
PublicationW artykule przedstawiono koncepcję i wynikające z niej problemy projektowania doków pływających w aspekcie niezawodności i bezpieczeństwa ich funkcjonowania. Zwrócono uwagę, że projektowanie takie jest niezbędne do uzyskania przez tego rodzaju doki odpowiednich własności proekologicznych. Wykazano konieczność stosowania projektowania wieloetapowego. Zaproponowano uwzględnienie w projektowaniu takich etapów jak: akwizycyjnego, kontraktowego,...
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A design proposal of driving system for roof segments and gantry crane of ecological floating dock
PublicationW pracy przedstawiono propozycję napędu segmentów przesuwnego zadaszenia oraz suwnicy ekologicznego doku pływającego. Proponowany układ napędowy oparto na zastosowaniu elektrycznych silników asynchronicznych z zewnętrznym sterowaniem częstotliwościowym prędkości obrotowej.
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Airborne Laser Scanning Point Cloud Update by Used of the Terrestrial Laser Scanning and the Low-Level Aerial Photogrammetry
PublicationLaser scanning technology is a spatial information gathering technique which is commonly used all over the world. Systems where the red-light beam are used, are divided into: terrestrial, mobile and airborne scanning systems. The main differences between those are the accuracy, the data acquisition solution (f. e. in ALS and MLS besides of the laser scanner, the inertial navigation system is required) and the covered area in one...
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ORF Approximation in Numerical Analysis of Fractional Point Kinetics and Heat Exchange Model of Nuclear Reactor
PublicationThis paper presents results concerning numerical solutions of the fractional point kinetics (FPK) and heat exchange (HE) model for a nuclear reactor. The model consists of a nonlinear system of fractional and ordinary differential equations. Two methods to solve the model are compared. The first one applies Oustaloup Recursive Filter (ORF) and the second one applies Refined Oustaloup Recursive Filter (RORF). Simulation tests have...
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ORF Approximation in Numerical Analysis of Fractional Point Kinetics and Heat Exchange Model of Nuclear Reactor
PublicationThis paper presents results concerning numerical solutions of the fractional point kinetics (FPK) and heat exchange (HE) model for a nuclear reactor. The model consists of a nonlinear system of fractional and ordinary differential equations. Two methods to solve the model are compared. The first one applies Oustaloup Recursive Filter (ORF) and the second one applies Refined Oustaloup Recursive Filter (RORF). Simulation tests have...
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Modification of the operating point of residual current transformers for high frequency earth fault currents detection
PublicationFor protection against electric shock in low voltage systems residual current devices are commonly used. However, their proper operation can be interfered when earth fault current with high frequency components occurs. Serious hazard of electrocution exists then. One of the most important element of residual current devices is a residual current transformer with iron core. Tripping characteristic of residual current devices strictly...
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Simplified probabilistic analysis of settlement of cyclically loaded soil stratum using point estimate method
PublicationThe paper deals with the probabilistic analysis of settlement of a non-cohesive soil layer subjected to cyclic loading. Originally, the settlement assessment is based on deterministic compaction model which requires integration of a set of differential equations. However, making use of the Bessel functions the settlement of the soil stratum can be calculated by means of simplified algorithm. The compaction model parameters were...
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Point cloud based surface analysis of prestressed concrete element in exceeded state of serviceability
PublicationBy definition, serviceability state is characterized by the fact that despite meeting the requirements associated with carrying capacity, the object is not suitable for use. Serviceability limit state refers to factors, such as durability, overall stability, fire resistance, cracking, excessive vibration. Perfect examples of exceeded serviceability state are the improper vibration of a skyscraper, which inhabitants may suffer from...
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Controlling nodal displacement of pantographic structures using matrix condensation and interior-point optimization: A numerical and experimental study
PublicationThis study presents an innovative approach for the precise control of nodal displacements in pantographic structures. The method is founded on the Matrix Condensation of Force Method, seamlessly integrated with an Interior Point Optimization algorithm. This combination offers a unique advantage by allowing users to manipulate displaced nodes within a defined coordination domain. Furthermore, this approach introduces the Interior...
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Time-domain description of point-source acoustic wavefields as a useful approach in ultrasonic techniques
PublicationIn traditional acoustics, field problems are usually treated in the frequency domain, broadband fields being reduced to superposition of harmonic spectrum components. However, this approach is inherently acausal and it is known that in case of arbitrary signals, the distribution-based, time-domain description can be more effective. The present paper is an attempt to expand the time-domain linear systems formalism onto space problems...
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Time-Domain Description of Point-Source Acoustic Wavefields as a Useful Approach in Ultrasonic Techniques
PublicationIn traditional acoustics, field problems are usually treated in the frequency domain, broadband fields being reduced to superposition of harmonic spectrum components. However, this approach is inherently acausal and it is known that in case of arbitrary signals, the distribution-based, time-domain description can be more effective. The present paper is an attempt to expand the time-domain linear systems formalism onto space problems...
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Influence of aggregates angularity on the locking point of asphalt mixtures
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Fixed point index for $G$-equivariant multivalued maps
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Periodicity of a sequence of local fixed point indices of iterations
PublicationPraca uogólnia klasyczne twierdzenie Shuba i Sullivana o periodyczności ciągu indeksów punktu stałego iteracji odwzorowań gładkich na szerszą klasę przekształeń.
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Local fixed point indices of iterations of planar maps
PublicationW artykule podana zostaje postać indeksów iteracji dla pewnej klasy odwzorowań planarnych. Podstawowymi narzędziami stosowanym w pracy są liczba Nielsena i indeks Conleya.
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Sequences of fixed point indices of iterations in dimension 2.
PublicationW pracy dowodzi się, że każdy ciąg liczb całkowitych spełniający relacje Dolda może zostać zrealizowany jako ciąg indeksów punktu stałego iteracji ciągłego odwzorowania dwuwymiarowego dysku w siebie.
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Photovoltaic maximum power point varying with illumination and temperature
PublicationW pracy przedstawiono wyniki badań eksperymentalnych zmian położenia punktu maksymalnej mocy na charakterystyce prądowo-napięciowej modułu ogniw fotowoltaicznych, związanych ze zmieniającą się temperaturą i natężeniem padającego promieniowania. Badano czas narastania napięcia pracy i temperatury ogniw w początkowej fazie ekspozycji na promieniowanie słoneczne. Przedstawiono niektóre praktyczne aspekty zastosowania układu automatycznego...