Filters
total: 14067
-
Catalog
displaying 1000 best results Help
Search results for: VECTOR-VALUED INTENSITY MEASURE, SPECTRAL SHAPE, RESIDUAL DRIFT ASSESSMENT, VISCOUS DAMPER, INCREMENTAL DYNAMIC ANALYSIS
-
Trees as a solar control measure for southern-oriented street frontages. Analysis of a selected street model for a humid continental climate
PublicationThe present study is aimed at the analysis of possibilities for shading southern frontage of street oriented along the E-W axis by the single row of trees, parallel to the southern elevations. The effectiveness of solar control shading was tested depending on the geometric relationships between trees and buildings. Numerical simulation analyses were conducted in Rhinoceros® program for the street located in humid continental climate...
-
Behavior of residual current devices at frequencies up to 50 kHz
PublicationThe use of residual current devices (RCDs) is obligatory in many types of low-voltage circuits. They are devices that ensure protection against electric shock in the case of indirect contact and may ensure additional protection in the case of direct contact. For the latter purpose of protection, only RCDs of a rated residual operating current not exceeding 30 mA are suitable. Unfortunately, modem current-using equipment supplied...
-
Failure of cold-formed beam: How does residual stress affect stability?
PublicationIn machine industry, stresses are often calculated using simple linear FEM analysis. Occasional failures of elements designed in such a way require recomputation by means of more sophisticated methods, eg. including plasticity and non-linear effects. It usually leads to investigation of failure causes and improvement of an element in order to prevent its unwanted behavior in the future. The study presents the case where both linear...
-
Systematic Assessment of Product Quality
PublicationThe article describes an innovative metrizable idea for systemic assessments of product quality within the baking industry. Complex product quality analysis requires the employment of metrizability criteria for factors that impact the quality of the product, and these are called determinants. Therefore, such analysis is only possible with the use of systems engineering. A system represents the potential of a manufacturing process,...
-
The Quick Measure of a Nurbs Surface Curvature for Accurate Triangular Meshing
PublicationNURBS surfaces are the most widely used surfaces for three-dimensional models in CAD/CAE programs. As a model for FEM calculation is prepared with a CAD program it is inevitable to mesh it finally. There are many algorithms for meshing planar regions. Some of them may be used for meshing surfaces but it is necessary to take the curvature of the surface under consideration to avoid poor quality mesh. The mesh must be denser in the...
-
Piezoelectric Transducer for Mechanical Assessment of Soft Tissues. Concept, Implementation and Analysis
PublicationThe main goal of this work was following: preparation of a new concept, implementation and analysis of the piezoelectric resonant sensor/actuator for measuring the aging process of human skin. The research work has been carried out in the framework of cooperation between the INP-ENSEEIHT-LAPLACE, Toulouse, France, and at the Gdansk University of Technology, Faculty of Electrical and Control Engineering, Research Group of...
-
DYNAMIC ANALYSIS OF THE IMPACT OF VIBRATION ON HISTORICAL BUILDINGS - AN OWN PROJECT OF EXTERNAL STAIRCASE
PublicationThis article presents numerical simulations that concern modeling of interaction of the external staircase’s construction with the observation deck on historic water tower located at Gdansk University of Technology. The interaction occurring according to various methods of the staircase's construction support on the wall of the historic tower was compared. The external staircase that allows for entering onto the monument was subjected...
-
DYNAMIC ANALYSIS OF THE RAILWAY BRIDGES IN POLAND WITH REGARDS TO HIGH-SPEED TRAINS PASSAGE ADJUSTMENT
PublicationThe dynamic analysis of the railway bridge in Tczew was carried out in the article as an example of such bridges adaptation suitability to handle high-speed trains. Calculations of railway bridges are greatly complicated and labor-consuming. The bridge model and a rolling stock passage simulation were developed in the SOFISTIK software. Three types of elements were used for the correct mapping of the structure in the calculation...
-
Stability Assessment of Coastal Cliffs Incorporating Laser Scanning Technology and a Numerical Analysis
PublicationWe investigated the cli coast in Jastrzebia Gora, Poland. The measurements that were taken between 2014 and 2018 by applying terrestrial, mobile, and airborne laser scanning describe a huge geometric modification involving dislocations in a 2.5 m range. Dierential maps and a volumetric change analysis made it possible to identify the most deformed cli’s location. Part of the monitoring of coastal change involved the measurement...
-
Frequency based criterion for distinguishing tonal and noisy spectral components
PublicationA frequency-based criterion for distinguishing tonal and noisy spectral components is proposed. For considered spectral local maximum two instantaneous frequency estimates are determined and the difference between them is used in order to verify whether component is noisy or tonal. Since one of the estimators was invented specially for this application its properties are deeply examined. The proposed criterion is applied to the...
-
JOURNAL OF VECTOR ECOLOGY
Journals -
A novel formulation of 3D spectral element for wave propagation in reinforced concrete
PublicationThe paper deals with numerical simulations of wave propagation in reinforced concrete for damage detection purposes. A novel formulation of a 3D spectral element was proposed. The reinforcement modelled as the truss spectral element was embedded in the 3D solid spectral finite element. Numerical simulations have been conducted on cuboid concrete specimens reinforced with two steel bars. Different degradation models were considered...
-
Application of fuzzy logic to determine the odour intensity of model gas mixtures using electronic nose
PublicationThe paper presents the possibility of application of fuzzy logic to determine the odour intensity of model, ternary gas mixtures (α-pinene, toluene and triethylamine) using electronic nose prototype. The results obtained using fuzzy logic algorithms were compared with the values obtained using multiple linear regression (MLR) model and sensory analysis. As the results of the studies, it was found the electronic nose prototype along...
-
Evaluation of applicability of classic methods of a fault loop impedance measurement to circuits with residual current devices
PublicationMeasurement of fault loop impedance in low voltage grids and systems is in most cases performed to verify the effectiveness of protection against electric shock by automatic disconnection of supply. For the sake of measurement accuracy, it is advisable to perform it using large current. Unfortunately, in circuits with residual current devices which are very widely used nowadays, a large measurement current may trigger those devices...
-
Behavior of residual current devices at earth fault currents with DC component
PublicationLow-voltage electrical installations are increasingly saturated with power electronic converters. Due to very high popularity of photovoltaic (PV) installations and the spread of electric vehicles (EV) as well as their charging installations, DC–AC and AC–DC converters are often found in power systems. The transformerless coupling of AC and DC systems via power electronic converters means that an electrical installation containing...
-
The innovative approach for using pavement as a fire prevention measure in tunnels
PublicationThe paper consists of two main parts: first presents study regarding the typically used pavement structures in tunnels and the second part: the first fire trials of the poroelastic SEPOR (Safe, Eco-friendly POroelastic Road Surface) mixture which was designed to be used among other uses in tunnels. In the first part of the paper different pavement materials, such as cement concrete, asphalt concrete, stone mastic asphalt and porous...
-
Buckling and shape control of prestressable trusses using optimum number of actuators
PublicationThis paper describes a method to control the nodal displacement of prestressable truss structures within the desired domains. At the same time, the stress in all members is unleashed to take any value between the allowable tensile stress and critical buckling stress. The shape and stresses are controlled by actuating the most active members. The technique considers the members’ initial crookedness, residual stresses, and slenderness...
-
On adaptive selection of estimation bandwidth for analysis of locally stationary multivariate processes
PublicationWhen estimating the correlation/spectral structure of a locally stationary process, one should choose the so-called estimation bandwidth, related to the effective width of the local analysis window. The choice should comply with the degree of signal nonstationarity. Too small bandwidth may result in an excessive estimation bias, while too large bandwidth may cause excessive estimation variance. The paper presents a novel method...
-
Timber-frame house resistant to dynamic loads - analysis of wall panel filled with polyurethane foam
PublicationThe present study shows the experimentally and numerically determined response of a single timber-frame house wall panel filled with polyurethane (PU) foam under dynamic loads. The harmonic tests were conducted for the following frequencies: 0.5 Hz, 1.0 Hz, 2.0 Hz and 5.0 Hz for various values of the specified displacement. Based on the results of the comparison between the experimental tests and the numerical analyses, the numerical...
-
Analytical procedures for quality control of pharmaceuticals in terms of residual solvents content: Challenges and recent developments
PublicationResidual solvents play an important role in the synthesis of drugs and in product formulations. In addition, they pose a serious problem, that is toxicity, as many of them exhibit toxic or environmentally hazardous properties. Therefore, constant monitoring of quality control is needed. In this study, we present an overview of regulatory and general methods described by various pharmacopoeias. Then, the most commonly used methodologies...
-
Enhancing Seismic Performance of Semi-rigid Connection Using Shape Memory Alloy Bolts Considering Nonlinear Soil–Structure Interaction
PublicationSteel Moment-Resisting Frames (SMRFs) have their lateral resistance for their rigid connections, while real conditions have shown that the rigidity of a connection depends on the bolts and the end-plate thickness, which may not provide the assumed rigidity in design process. In this research, the main goal is to enhance the semi-rigid connections using shape memory alloy (SMA) bolts and explore their effects on the seismic limit-state...
-
Numerical Comparison of Damping Amplification Effects Obtained in Neighborhood of a Mechanism Singular Position - Viscous and Electromagnetic Cases
PublicationIn the paper, results of numerical investigations are presented. A continuous beam is considered as the main vibrating element. Two energy dissipations methods are compared: viscous dampers and DC generators. To increase the damping effectiveness, velocity amplification is proposed, i.e., a mechanism is introduced between the beam and the damping element, and the mechanism configuration is set as closed to the singular position...
-
Fatigue life improvement using low transformation temperature weld material with measurement of residual stress
PublicationWelding processes often produce high levels of tensile residual stress. Low transformation temperature (LTT) welding wires utilise phase transformation strains to overcome the thermal contraction of a cooling weld. In this paper, the residual stress within each weld was quantified using the milling/strain gauge method, being the strain change measured as the weldment was milled away. The fatigue tests were conducted under uniaxial...
-
Electronic and nuclear properties from the analysis of the isotope shifts in the spectral lines of lead
Publication -
Synthesis and application of doxorubicin-loaded silica gels as solid materials for spectral analysis
Publication -
The spectral finite element model for analysis of flexural–shear coupled wave propagation
Publication -
Quadratic Cohen representations in spectral analysis of serration process in Al-Mg alloys
PublicationIstotny z mechanicznego punktu widzenia efekt Portevina Le-Chateliera charakteryzuje się skomplikowanym profilem widmowym. Jako typowy przykład procesu niestacjonarnego, wymaga specjalnego podejścia umożliwiającego analizę zmian rozkładu energii fluktuacji naprężenia w funkcji odkształcenia. Jako narzędzie umożliwiające realizację powyższego założenia autorzy proponują zastosowanie rodziny przekształceń kwadratowych znanych jako...
-
Drift, wow and flutter measurement and reduction in shrunken movie soundtracks
PublicationReferat przedstawia metodę i algorytmy do oceny i redukcji dryfu, kołysania i drżenia w skurczonych taśmach filmowych. Przedstawione algorytmy działają w oparciu o przetwarzaniu obrazu taśmy filmowej w celu wyznaczenia jej lokalnego skurczu, który jest jednym z powodów powstawania dryfu, kołysania i drżenia. Lokalny skurcz taśmy można wyznaczyć dzięki analizie wysokości: ramki obrazu, perforacji, lub innego, standaryzowanego elementu...
-
Calibration of acoustic vector sensor based on MEMS microphones for DOA estimation
PublicationA procedure of calibration of a custom 3D acoustic vector sensor (AVS) for the purpose of direction of arrival (DoA) estimation, is presented and validated in the paper. AVS devices working on a p-p principle may be constructed from standard pressure sensors and a signal processing system. However, in order to ensure accurate DoA estimation, each sensor needs to be calibrated. The proposed algorithm divides the calibration process...
-
The Application of Cluster Analysis in the Assessment of the Weldability of Unalloyed Steels
PublicationNon-alloy steels constitute a large group of steels characterised by diversified chemical composition, structural morphology and a wide range of mechanical properties (determining weldability). The paper presents results of multidimensional analyses (based on cluster analysis) of 110 selected unalloyed steel grades. Properties adopted as diagnostic features included the chemical composition, mechanical properties (yield point)...
-
Polynomial analysis as a new way of describing dynamic impedance spectra – Differential and relative impedance spectra
PublicationModel measurements of an equivalent electrical system were carried out using the technique of Dynamic Electrochemical Impedance Spectroscopy. The measurement took the form of potentiodynamic changes imposed on the tested system. Using the possibility of continuous impedance measurements, an attempt was made to develop an original and innovative method of analyzing impedance spectrograms, which is termed polynomial analysis. As...
-
Using differential pressure sensor to measure nitrous oxide level in a tank
PublicationA method for measuring the level of liquid nitrous oxide oxidizer in a hybrid rocket motor oxidizer tank is proposed. Presented approach is more accurate than the most commonly used method of this measurement, which employs weighting of the whole sounding rocket or an oxidizer tank. In our solution we use a differential pressure sensor to measure the change of pressure at the bottom of an oxidizer tank in comparison to the pressure...
-
Decisions Analysis 2023/2024
e-Learning CoursesThis is content to the subject: "Decisions Analysis" to be used as a template for futher courses.
-
Qualitative data analysis methods
e-Learning CoursesThis is the continuation of Qualitatative Data Analysis Methods course provided online
-
Image Quality Assessment Tool for Conventional and Dynamic Magnetic Resonance Imaging Acquisitions
Publication -
Selecting an Applicable Cybersecurity Assessment Framework: Qualitative Metrics-Based Multiple-Factor Analysis
PublicationRecently, a survey of cybersecurity assessment methods focused on general characteristics was conducted. Among its major findings, it revealed the methods’ adoption issues. This paper presents a follow-up to the study. It provides an in-depth analysis of the methods’ adoption-related properties based on qualitative metrics. As a result, the proposals which demonstrate a higher adoption potential were identified. The methods are...
-
Spectral Clustering Wikipedia Keyword-Based search Results
PublicationThe paper summarizes our research in the area of unsupervised categorization of Wikipedia articles. As a practical result of our research, we present an application of spectral clustering algorithm used for grouping Wikipedia search results. The main contribution of the paper is a representation method for Wikipedia articles that has been based on combination of words and links and used for categoriation of search results in this...
-
Experimental verification of a new method of loop resistance testing in low voltage systems with residual current devices
PublicationA periodical verification of the effectiveness of protection against electric shock shall be performed in low voltage systems. The scope of this verification includes loop impedance/resistance testing. If a residual current device is installed in a tested circuit, this testing is problematic. A residual current device trips out during the test, because of the high value of measurement current. This precludes the execution of the...
-
Comparison of low-temperature cracks intensity on pavements with high modulus asphalt concrete and conventional asphalt concrete bases
PublicationHigh modulus asphalt concrete (HMAC) base courses provide very good resistance to rutting and fatigue but they can increase the risk of low-temperature cracking as compared with conventional asphalt concrete (AC). The article presents the comparison of these two road materials in terms of low-temperature cracking. The statistical method based on the ordered logistic regression model was used. The analysis was based on results of...
-
Estimation and tracking of complex-valued quasi-periodically varying systems
PublicationW artykule rozważany jest problem identyfikacji obiektów o parametrach zmieniających się w sposób pseudookresowy. Przedstawiono w nim algorytm oparty o metodę funkcji bazowych umożliwiający śledzenie takich obiektów oraz pokazano atrakcyjne z punktu widzenia złożoności obliczeń jego wersje zdekomponowane. Przydatność rozważanych algorytmów uzasadniono porównując je z rozwiązaniami innych autorów.
-
Generalized adaptive notch smoothers for real-valued signals and systems
PublicationSystems with quasi-periodically varying coefficients can be tracked using the algorithms known as generalized adaptive notch filters (GANFs). GANF algorithms can be considered an extension, to the system case, of classical adaptive notch filters (ANFs). We show that estimation accuracy of the existing algorithms, as well as their robustness to the choice of design parameters, can be considerably improved by means of compensating...
-
Spectral sequences and detailed connection matrices
Publication -
Face Recognition: Shape versus Texture
PublicationThis paper describes experiments related to the application of well-known techniques of the texture feature extraction (Local Binary Patterns and Gabor filtering) to the problem of automatic face verification. Results of the tests show that simple image normalization strategy based on the eye center detection and a regular grid of fiducial points outperforms the more complicated approach, employing active models that are able to...
-
Software Tools to Measure the Duplication of Information
PublicationData stored in average computer system usually is not unique, portions of stored data are duplicated. When duplicated data are stored in separate files containing source code of computer program of student homework, a possibility of cheating should be seriously considered. This paper presents software tools built, in order to detect re-use of pieces of code in supplied text files. Three aspects of information atching are considered:...
-
Simple measure of typewriter prints quality
PublicationArtykuł przedstawia opracowaną przez autora metodę określania kształtu zaadaptowaną do szacowania jakości znaków uzyskiwanych na maszynie do pisania. Metoda ta bazuje na statystycznej analizie odwzorowania maksymalnego kwadratu (ang. Maximal Square Map) opisanej w szczegółach w artykule. Metodę opracowano celem szacowania jakości komputerowo wspomaganego pozyskiwania informacji z archiwalnych maszynopisów.
-
A new method of fault loop resistance measurement in low voltage systems with residual current devices
PublicationThis paper presents a new method of fault loop resistance measurement in low voltage systems with residual current devices. The method enables measuring fault loop resistance without nuisance tripping of residual current devices, by application an unconventional waveform of measurement current. It is important for proper verification of the effectiveness of protection against electric shock.
-
Influence of the grains shape on the mechanical behavior of granular materials
PublicationDiscrete Element Method is a numerical method suitable for modeling geotechnical problems concerning granular media. In most cases simple forms of grains, like discs or spheres, are used. But these shapes are capable of soil behavior modeling up to a certain point only, they cannot reflect all of the features of the medium (large shear resistance and large volumetric change). In order to reflect the complex behavior of the real...
-
Wojciech Kustra dr inż.
PeopleI am a Faculty member (Assistant Professor, Highway and Transportation Engineering Department) at the Faculty of Civil and Environmental Engineering, Gdansk University of Technology, Poland). My main research interests include: road safety, accident analysis, traffic modeling, transportation planning, traffic engineering, transport management, gis analysis.
-
MEASUREMENT AND ANALYSIS OF ELECTRIC FIELD INTENSITY NEAR SELECTED TRANSMITTERS OF MOBILE TELEPHONY BASE STATIONS
PublicationWireless connectivity has become increasingly common in recent times. Day by day, there are more radiocommunication devices and new ideas for them. In the near future, when the fifth generation networks will be implemented, whose main feature will be continuous wireless communication, we must approach the issue of electric field measurements more and more carefully.
-
Dynamic Games and Applications
Journals