Filtry
wszystkich: 2005
wybranych: 1648
-
Katalog
Filtry wybranego katalogu
wyświetlamy 1000 najlepszych wyników Pomoc
Wyniki wyszukiwania dla: Accident reconstruction
-
The influence of accumulation area and the length of pedestrian route on functioning of roundabouts with traffic signals
Publikacjatraffic volumes. This kind of intersection is commonly used in the centres of Polish cities on multilane roads and fairly common in the case of tram lines running through a central island. The increase of traffic flow volumes on left turn and U-turn has made this type of roundabout difficult to operate. Small storage areas around central islands are critical places that significantly influence the capacity of this kind of intersection....
-
Stiffness change of abdominal prosthesis Optomesh™ under cyclic loading
PublikacjaAbdominal prostheses are used in humans for abdominal wall strengthening or reconstruction. From the mechanical point of view they are membranes, so their basic mechanical property is tensile stiffness. This property is experimentally identified for a selected implant, OptomeshTM. The obtained results are described herein. Uni-axial simple and cyclic tension tests are a basis for the analysis. Both kinds of tests allowed to distinguish...
-
Demolition of the cereal elevator building located in the conservation protection zone in the aspect of technical, functional-utility and economic conditions
PublikacjaThe paper presents a description of the technical condition of the Grain Elevator building situated on the port quay, which after many years of operation has been decommissioned. The immediate reason for the cessation of operation was the change in the use profile of the port quay, which caused the handling of other goods at the quay than the bulk materials originally stored in Elewator Zbożowy. The work contains...
-
Corrosion degradation monitoring of ship stiffened plates using guided wave phase velocity and constrained convex optimization method
PublikacjaThe study presents an experimental investigation on the corrosion degradation level assessment using nondestructive wave-based methods. The degradation level of ship structural elements has been assessed in two different ways. The first one is based on the spectral decomposition and zero-crossing incorporated reconstruction of the dispersion curve approach of the antisymmetric Lamb wave mode and the best matching of the theoretical...
-
Valuation of architectural heritage by multicultural student groups
PublikacjaIn this article, the author addresses the education of architecture students in the field of architectural history and the determination of the value of architectural objects. Important changes at present are underway concerning this. Both the role of architectural history in architectural education and content in architectural history curricula is changing. The need for re-evaluation...
-
Vernacular and low-tech technologies in humanitarian architecture on the example of Senegal
PublikacjaHumanitarian architecture belongs to the broader trend of socially engaged architecture, whose main goal is to introduce new values to the quality of life of particular communities. Specifically, humanitarian architecture deals with aid to poverty-stricken communities. The context of economic constraints poses a particular challenge to architects and builders. It is a matter of natural necessity to look for cheap, locally available...
-
Predicting Performance of Lightweight Concrete with Granulated Expanded Glass and Ash Aggregate by Means of Using Artificial Neural Networks
PublikacjaLightweight concrete (LWC) is a group of cement composites of the defined physical, mechanical, and chemical performance. The methods of designing the composition of LWC with the assumed density and compressive strength are used most commonly. The purpose of using LWC is the reduction of the structure’s weight, as well as the reduction of thermal conductivity index. The highest possible strength, durability and low thermal conductivity...
-
Diagnostics and monitoring of the longest span extradosed bridge in Europe
PublikacjaThe article presents complex diagnostic procedures applied for the purpose of behavior analysis of the extradosed bridge with the longest span in Europe that was built in 2018 in Poland. The system of health monitoring was used to: register internal forces in temporary supports, monitor concrete bonding, perform in situ diagnostics and operation tests. The bridge is a continuous four-span structure with spans theoretical lengths...
-
Diagnosing wind turbine condition employing a neural network to the analysis of vibroacoustic signals
PublikacjaIt is important from the economic point of view to detect damage early in the wind turbines before failures occur. For this purpose, a monitoring device was built that analyzes both acoustic signals acquired from the built-in non-contact acoustic intensity probe, as well as from the accelerometers, mounted on the internal devices in the nacelle. The signals collected in this way are used for long-term training of the autoencoder...
-
Sea bottom structure investigation by means of acoustic methods
PublikacjaThe main aim of the paper is the result of experimental investigations of the seabed in the Gulf of Gdańsk arried out using parametric echosounder as a main measuring tool. Examination of the surface's upper layer of the seabed, especially is acoustic properties, reflecting most often transsmision and reflection properties of the incident elastic wave, could be a valuable material for determination of the stratification, and the...
-
seafloor characterisation combined approach using multibeam sonar echo signal processing and image analysis
PublikacjaThe authors propose the approach to seafloor characterisation which relies on the combined, concurrent use of two different techniques: (i) multibeam sonar image analysis and (ii) multibeam seabed echoes processing. The first technique is based on constructing the grey-level sonar images of the seabed extracted from the echoes received in the consecutive soundings. Then, the set of parameters describing the local region of sonar...
-
FDTD Simulations on Disjoint Domains with the Use of Discrete Green's Function Diakoptics
PublikacjaA discrete Green's function (DGF) approach to couple disjoint domains in the finite-difference time-domain (FDTD) grid is developed. In this method, total-field/scattered-field (TFSF) FDTD domains are associated with simulated objects whereas the interaction between them is modeled with the use of the DGF propagator. Hence, source and scatterer are simulated in separate domains and updating of vacuum cells, being of little interest,...
-
Reliability assessment of an OVH HV power line truss transmission tower subjected to seismic loading
PublikacjaThe study focuses on the reliability of a transmission tower OS24 ON150 + 10, an element of an OVH HV power line, under seismic loading. In order to describe the seismic force, the real-life recording of the horizontal component of the El Centro earthquake was adopted. The amplitude and the period of this excitation are assumed random, their variation is described by Weibull distribution. The possible space state of the phenomenon...
-
NUMERICAL ESTIMATION OF HULL HYDRODYNAMIC DERIVATIVES IN SHIP MANOUVERING PREDICTION
PublikacjaOperating in crowded waterways pose a risk of accidents and disasters due to maneuvering limitations of the ship. In order to predict ship’s maneuvering characteristics at the design stage, model tests are often executed as the most accurate prediction tool. Two approaches can be distinguished here: free running model tests and numerical simulations based on planar motion model with the use of hydrodynamic derivatives obtained...
-
Pedestrian detection in low-resolution thermal images
PublikacjaOver one million people die in car accidents worldwide each year. A solution that will be able to reduce situations in which pedestrian safety is at risk has been sought for a long time. One of the techniques for detecting pedestrians on the road is the use of artificial intelligence in connection with thermal imaging. The purpose of this work was to design a system to assist the safety of people and car intelligence with the use...
-
Redesigning Informal Beirut: Shaping the Sustainable Transformation Strategies
PublikacjaLebanon is distinguished by its strategic geographical location among the Arab countries. Beirut, as the capital city and the major commercial and cultural centre of the country, is a point of interest for migrants. The region has witnessed many changes since the end of World War II, which have resulted in internal and external conflicts, migrations, the centralization of the country’s economy, etc. Furthermore, the city has witnessed...
-
Design and evaluation of a base module of active power electronic transformer
PublikacjaThis paper presents an active power electronic transformer (APET) based on modular structure. The proposed three phase APET consists of at least three base modules (BM). The input/output stage of the BM is based on half-bridge sub modules. The isolation stage includes a medium frequency transformer and is realized as a dual half-bridge. The paper describes construction process and explains the control strategy. The theoretical...
-
Crystallization of space: Space-time fractals from fractal arithmetic
PublikacjaFractals such as the Cantor set can be equipped with intrinsic arithmetic operations (addition, subtraction, multiplication, division) that map the fractal into itself. The arithmetics allows one to define calculus and algebra intrinsic to the fractal in question, and one can formulate classical and quantum physics within the fractal set. In particular, fractals in space-time can be generated by means of homogeneous spaces associated...
-
Reducing of energy consumption in public transport - results of experimental exploitation of super capacitor energy bank in Gdynia trolleybus system
PublikacjaPaper presents the result of test exploitation supercapacitor energy bank in Gdynia trolleybus system. In the first part of the article the basics of the regenerative breaking are presented and the construction and control strategy of the supercapacitor bank are described. The area of research and method of measurement are explained. In the second part of paper the results of tests and measurements are described. Emphasis was placed...
-
Historical crane on the redesigned original trestle bridge as a memorial of Gdansk Shipyard
PublikacjaThe paper includes selected aspects of the study, whose goal is to hold the historical crane 642-24 in its current location after the modification of trestle bridge static scheme. The scope of the paper includes the assessment of current technical condition of the object, a presentation of FEM analyses, a description of the assumed load cases, results of the static calculations, checking the effort of construction elements, global...
-
The overview of reactors used for the production of precipitated calcium carbonate via carbonation route
PublikacjaCarbonation is one of the methods for the production of precipitated calcium carbonate (PCC) on the industrial scale. A gaseous CO2 is used as a reagent in this process. The hydrodynamic conditions gener-ated in the reactor affect the course of the process and the characteristics of the precipitated calcium carbonate particles. This paper discusses the construction of standard reactors and new proposed con-struction used for the...
-
Building modernization located in the conservation protection zone in the aspect of technical conditions
PublikacjaThe paper presents a description of the technical condition of the building after many years of operation and analyzes the impact of the current use and the lack of regular periodic repairs on the technical efficiency of the building. The influence of the technical solutions applied during the construction of the building on the current limitations related to the planned, target change in the way of use was discussed. Variant conceptual...
-
Three-Level Z-Source Neutral-Point-Clamped Inverter
PublikacjaThe paper describes construction and the principles of activity, attributes and potential of 3-phase Z-type inverters. The paper focuses on the basic system and suggested 3-level system of a NPC type Z-inverter, which was elaborated by authors. Simplified theoretical analysis of both systems has been verified by detailed simulation research. In the last section of the article, the possibility to build multilevel Z- inverters based...
-
Voltage Source Power Line Conditioner for Applications in Local Supply Systems
PublikacjaThe paper presents the basic principles of operation of voltage source power line conditioners (VSPLC) as well as their energy and filtration properties. A 4-level cascade based Voltage Source Converter (VSC) is used as a voltage source. The advantages of this topology is relatively simple construction and simple way of balancing DC link voltages. Results of the theoretical and experimental investigations confirm good energetic...
-
New Design of Axial Piston Pump with Displaced Swash Plate Axis of Rotation for Hydro-Mechanical Transmissions
PublikacjaThis paper presents a prototype design of an axial piston pump with displaced swash plate axis of rotation in two directions of discharge with electronic control intended for installation on a hydraulic-mechanical gearbox dedicated to working machines. The effect of displacement of the swash plate rotation axis on dead space volume and volumetric efficiency is presented. The construction and principle of operation of the capacity...
-
Wzbudzone siły wewnętrzne : skutki upr0szczonego modelowania zakrzywionej estakady sprężonej
Publikacjathe paper presents problems, which were encountered during the construction of a southern road bypass of city gdansk. after prestressing and removing formwork, the contractor spotted, that some of outer bearings are detached. performed analysis showed that, this situation was caused by the usage of a simplified, straight beam model during design phase. the paper shows the influence of a curved in plane prestressed system on internal...
-
Several notes on technical modernization of a historical building
PublikacjaThis paper describes methods and means used during the renovation process of several elements of a building – the assembly hall, inner courtyards and attics of the main building at Gdansk University of Technology, both in design and construction domains. A tissue of a historic building required special approach to these tasks, with special emphasis on good recognition of problems, careful planning and consistent implementing of...
-
Density smoothness estimation problem using a wavelet approach
PublikacjaIn this paper we consider a smoothness parameter estimation problem for a density function. The smoothness parameter of a function is defined in terms of Besov spaces. This paper is an extension of recent results (K. Dziedziul, M. Kucharska, B. Wolnik, Estimation of the smoothness parameter ). The construction of the estimator is based on wavelets coefficients. Although we believe that the effective estimation of the smoothness...
-
Multipulse inverter structures with low voltage distortion
PublikacjaA novel approach to the voltage source inverters (VSI) construction is presented in the paper. The invented inverter structures allow to operate several DC/AC converters in parallel resulting in lower voltage distortions at extremely low switching frequency. The research presented in the paper describes such a parallel operation of the VSI’s which is possible thanks to the use of coupled inductors. The eighteen-pulse three-level...
-
Application of the Optimum Dataset Method in Archeological Studies on Barrows
PublikacjaLight Detection and Ranging (LiDAR) became one of the technologies used in archaeological research. It allows for relatively easy detection of archaeological sites that have their own field form, e.g.: barrows, fortresses, tracts, ancient fields [1]. As a result of the scanning, the so-called point cloud is obtained, often consisting of millions of points. Such large measurement datasets are very time-consuming and labor-intensive...
-
Approach to security assessment of critical infrastructures' information systems
PublikacjaThis study presents an approach to the security assessment of the information systems of critical infrastructures. The approach is based on the faithful reconstruction of the evaluated information system in a computer security laboratory followed by simulations of possible threats against the system. The evidence collected during the experiments, stored and organised using a proprietary system InSAW, may later be used for the creation...
-
Non-Adaptive Speed and Position Estimation of Doubly-Fed Induction Generator in Grid-Connected Operations
PublikacjaThe nonadaptive speed and position estimation scheme for a doubly-fed induction generator (DFIG) is presented in this article. The observer structure is based on the extension of the mathematical model of DFIG to the introduced H vector. Based on the defined H vector, the nonadaptive position and speed estimation is proposed. The Lyapunov method is extended to the practical stability theorem to stabilize the structure. The classic...
-
Comparison of the exponential thermal transient parameterization methods with the SMTP method in the unipedicled DIEP flap computer modelling and simulation
PublikacjaThe aim of this paper is to compare the spatial contrast of the image descriptors obtained via three different thermal transient parameterization methods in Active Dynamic Thermography. The thermal constants and amplitude values of the one- and two- exponential parametrization are compared to the Simplified Magnitude-Temporal Parametrization method (SMTP). The comparison is performed using the data obtained by simulating the cold...
-
The two ring road complexes of Gdansk
PublikacjaThe urban structure of Gdańsk city centre is determined by two ring road complexes. The first of them, the Gdańsk Ring, has been designed by Hermann Josef Stübben as a result of a defortification at the turn of the 19th and 20th centuries. This new modern zone of the city centre was destroyed like the rest of Gdańsk in the end of World War Two and had not been reconstructed as a result of de-Germanization of the Recovered Territories....
-
Study on Strategy in University Laboratory Class Teaching
PublikacjaLaboratory teaching is a critical way to ensure the effective input of techniques in engineering learning. Laboratory teaching not only contributes to improving course quality but also helps enrich comprehensive engineering application ability. However, there are some typical problems in current university laboratory teaching, such as rigid and isolated course design, outdated contents and materials, and not encouraging innovation...
-
Travelling Architecture: Vanishing heritage of Gypsy caravans in Poland
PublikacjaThe wandering Gypsy/Roma groups began arriving in the territory of Poland in the fifteenth century. Leading a nomadic life, they did not develop any form of a built house until the nineteenth century, until the first wooden caravans appeared. In the twentieth century, the architecture of Gypsy caravans began to thrive. They developed into several different forms of meticulously decorated wooden mobile houses. At the same time however,...
-
Cost-Efficient Globalized Parameter Optimization of Microwave Components through Response-Feature Surrogates and Nature-Inspired Metaheuristics
PublikacjaDesign of contemporary microwave devices predominantly utilizes computational models, including both circuit simulators, and full-wave electromagnetic (EM) evaluation. The latter constitutes the sole generic way of rendering accurate assessment of the system outputs that considers phenomena such as cross-coupling or radiation and dielectric losses. Consequently, for reliability reasons, the final tuning of microwave device parameters...
-
ASSESSMENT OF CLIFF STABILITY AFTER THE DEMOLITION OF THE ENGINEERING FACILITIES
PublikacjaAs a part of an experiment, cliff in Gdynia Redlowo (southern coast of Baltic Sea, Gdansk Bay) was measured using terrestrial laser scanner. The main reason for taking up the subject of the Orlowo Cliff’s stability was a decision about controlled removal one of the war fortification elements. The main purpose of that analysis was to specify suitability of laser scanning in determination of slope’s stability after a violent event....
-
Performance analyses of helical coil heat exchangers. The effect of external coil surface modification on heat exchanger effectiveness
PublikacjaThe shell and coil heat exchangers are commonly used in heating, ventilation, nuclear industry, process plant, heat recovery and air conditioning systems. This type of recuperators benefits from simple construction, the low value of pressure drops and high heat transfer. In helical coil,centrifugal force is acting on the moving fluid due to the curvature of thetube results in the development. It has been long recognized that the...
-
Optical properties of thin TiO2 film deposited on the fiber optic sensor head
PublikacjaThe presented study was focused on investigation of the titanium dioxide (TiO2) thin film deposited on the fiber tip. The intention of this investigation was using TiO2 film in the construction of the optical fiber sensor head. In the demonstrated construction TiO2 thin layer was deposited on the tip of a commonly used telecommunication single mode optical fiber (SMF-28) by means of the Atomic Layer Deposition (ALD). Thickness...
-
Comparison of strain results at a laser weld notch obtained by numerical calculations and experimental measurements
PublikacjaIn the development of ship structures applying new materials and it’s purposeful placement play an important role. During the last years, especially in a construction of ro-ro type vessels, the usage of novel sandwich structures in cargo decks is profitable. Steel sandwich panel is an innovative solution which at a todays state of development can be used for the construction of any members not taking part in a global bending of...
-
Mechanical-Level Hardware-In-The-Loop and Simulation in Validation Testing of Prototype Tower Crane Drives
PublikacjaIn this paper, the static and dynamic simulations, and mechanical-level Hardware-In-the-Loop (MHIL) laboratory testing methodology of prototype drive systems with energy-saving permanent-magnet electric motors, intended for use in modern construction cranes is proposed and described. This research was aimed at designing and constructing a new type of tower crane by Krupiński Cranes Company. The described research stage was necessary...
-
Photogrammetric and computerized report on site model in feasibility study of navigability channel on vistula spit
PublikacjaIn the report the authors present a course of geodesic and geo-computerized works upon realization of feasibility study of navigability channel on Vistula Spit. A procedure of acquiring verification and modeling of data for requirements of a numeric model of a bottom and site has been presented with construction of original software for 3D visualization of the Vistula Spit area. The activities described in the report can be...
-
Reliability estimation of underground horizontal fuel tank limit states
PublikacjaFuel tanks are designed with regard to standard loads and operating conditions. The investigations of the paper show the impact of such factors as tank corrosion and other means on the variation of stress fields and deformation of the underground horizontal tank shell. The introduction of probabilistic methods allows for structural reliability assessment. While the computational time of the entire tank FEM model is high, the preliminary...
-
Influence of the position of the swash plate rotation axis on the volumetric efficiency of the axial pistons pumps
PublikacjaThe article describes the influence of the position of the swash plate axis of rotation on the size of the dead space and the volumetric efficiency of the axial pistons pump. Superposition of the two motions have been proposed - the rotation of the swash plate with respect to axis intersecting the axis of rotation of the pump shaft and the shifts of swash plate yielding a result of the rotation axis offset effect. In the article...
-
Alternative Energy: Photovoltaic Modules and Systems
PublikacjaUse of solar energy does not contribute to global warming. The light-to-current conversion (photovoltaic conversion) takes place within solar cells, which in most cases are made of silicon. Solar module consists of many solar cells, which are electrically connected and placed between glass or Tedlar® and framed by an aluminium frame. A number of solar modules and other components form photovoltaic systems. In this entry, a brief...
-
Power electronic systems as a crucial part of Smart Grid infrastructure - a survey
PublikacjaThis article gives a tutorial overview of the most important issues related to the use of power electronic systems in power engineering, with respect to the urgent need for modernization of existing grids in the direction of intelligent networks. The main problems and conditions bound up with the construction of Smart Grids and the location, as well as functioning in them of the most important power electronic systems are presented...
-
Multi-Option Model of Railway Traffic Organization Including the Energy Recuperation
PublikacjaThe article presents the issue of organization of railway traffic within the station, taking into account energy recuperation. We identified a number of factors which affect the energy efficiency of recuperation, including the issue of transfer of energy technology between a few vehicles. We presented some aspects of the decision problem of graphic train timetable construction with regard to recuperation. As an indicator of quality...
-
Application of mesh deformation for modeling of conformal RF components with 3D FEM
PublikacjaIn this paper, a method of analysis of conformal RF components has been proposed. In this approach, modeling of a curved structure is based on mesh deformation of planar objects rather than the construction of conformal geometry at CSG level. Since the model is represented as a 3D mesh, the deformation only requires the calculation of nodes position in the bent structure. The results of the proposed algorithm have been validated...
-
1D portable optical coherence tomography system
Publikacja—Imaging methods are an expanding branch of technology, which involves data acquisition and analysis of images for research and diagnostics. This paper has been devoted to the description of the optical design for a one-dimensional, portable optical coherence tomography (OCT) system. The Mach-Zehnder interferometer has been designed in the presented study. The description of the construction and applied hardware solutions have...