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Search results for: WEIGHTED LINEAR REGRESSION
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Polyester sail technical woven fabric behaviour under uniaxial and biaxial tensile tests
PublicationThe paper is focused on the identification of mechanical properties of a sail technical woven fabric (yacht sailcloth polyester) style 480 AP with MTO (Medium Tempered Optimized) finish. The non-linear elastic behaviour of the fabric applied for sails is investigated under uniaxial and biaxial tensile tests. Comparison of non-linear elastic parameters with others polyester coated fabrics is made. This paper is intended to be an...
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3D Buckling Analysis of a Truss with Horizontal Braces
PublicationThe present research is devoted to the study of out–of–plane buckling of a truss with horizontal braces. The truss is a model of real roof truss scaled by factor 1=4. A linear buckling and a non–linear analysis with geometric and material non–linearity were carried out. The truss buckling and limit load for different stiffnesses and number of braces are found. Numerical analysis are verified by experiment. Threshold bracing stiffness condition...
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Deep neural networks for human pose estimation from a very low resolution depth image
PublicationThe work presented in the paper is dedicated to determining and evaluating the most efficient neural network architecture applied as a multiple regression network localizing human body joints in 3D space based on a single low resolution depth image. The main challenge was to deal with a noisy and coarse representation of the human body, as observed by a depth sensor from a large distance, and to achieve high localization precision....
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Stability of roof trusses stiffened by corrugated sheets
PublicationThe present parametric study is devoted to the stability analysis of a set of trusses stiffened by decking of corrugated steel sheets. For different parameters of corrugated sheets the critical loading of the roof is calculated. In the parametrical analysis the threshold bracing condition of the roof is obtained. Then the geometrically non-linear analysis of trusses braced by corrugated sheets was conducted. As a results of non-linear...
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Improving the accuracy of bearing in active sonar with cylindrical array using spectrum estimation.
PublicationThe articles presents a method for improving the accuracy of bearing in multibeam sonar with a cylindrical array. Based on a known spatial spectrum estimation technique, the method has been successfully used in linear array systems. Its accuracy of bearing is satisfactory and ensures a relatively low computational effort. The article discusses certain simplifications and assumptions to adapt the spatial spectrum estimation technique...
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The influence of pressure drop on the working volume of a hydraulic motor
PublicationReliability and maintenance analysis of hydraulic positive machines basicly focused on the processes of their wear and failure. But in order to correctly assess the mechanical and volumetric efficiency of a hydraulic motor, both at the stage of development research or at the stage of control tests during its exploitation, the working volume of this motor must be correctly determined. Therefore this paper proposes a new method of...
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Impact of Low Switching-to-Fundamental Frequency Ratio on Predictive Current Control of PMSM: A simulation study
PublicationPredictive current control algorithms for permanent magnet synchronous (PMSM) drives rely on an assumption that within short intervals motor currents can be approximated with linear functions. This approximation may result either from discretizing the motor model or from simplifications applied to the continuous-time model. As the linear current approximation has been recognized as inaccurate in case when the drive operates with...
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Analytical method of modelling the geometric system of communication route
PublicationThe paper presents a new analytical approach to modelling the curvature of a communication route by making use of differential equations. The method makes it possible to identify both linear and nonlinear curvature. It enables us to join curves of the same or opposite signs of curvature. Solutions of problems for linear change of curvature and selected variants of nonlinear curvature in polynomial and trigonometric form were analyzed....
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Innovative Cold-formed GEB Section under Bending
PublicationThis paper is concerned with the numerical bending capacity study of the innovative cold-formed GEB sections. Both linear buckling analysis and non-linear static analysis incorporating geometric and material nonlinearity were carried out employing a shell structural model. The magnitudes of buckling load and limit load with respect to GEB section depth and thickness were obtained. The opened cold-formed section was tested assuming...
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Supervised Model Reference Adaptive Control of Chlorine Residuals in Water Distribution Systems
PublicationControl of integrated quality and quantity in Drinking Water Distribution Systems within recently proposed hierarchical framework is considered in the paper. A supervised nonlinear Indirect Model Reference Adaptive Controller is derived for the lower control level of the control structure to operate as the fast feedback controller of chlorine residuals in the monitored nodes. The major supervisor role is to manage switching between...
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Comparison of GPS tropospheric delays derived from two consecutive EPN reprocessing campaigns from the point of view of climate monitoring
PublicationThe main purpose of this research was to acquire information about consistency of ZTD (zenith total delay) linear trends and seasonal components between two consecutive GPS reprocessing campaigns. The analysis concerned two sets of the ZTD time series which were estimated during EUREF (Reference Frame Sub-Commission for Europe) EPN (Permanent Network) reprocessing campaigns according to 2008 and 2015 MUT AC (Military University...
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Does migration lead to economic convergence in an enlarged European market?
PublicationThis paper examines the relationship between migration and convergence for the enlarged internal market of the European Union (EU27) for the period 1990-2007. The impact of migration on growth is estimated in two ways: by including the migration rate in a growth regression and examining its impact on the convergence coefficient; and from the actual coefficient on migration, which can be interpreted as the effect of migration on...
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Dew Formation and Chemistry Near a Motorway in Poland
PublicationIn this study, the influence of traffic intensity on dewformation efficiency and chemistry is presented. The measurementswere conducted near the A4 motorway in SW Poland in almost flatland relief with intense agricultural activity. The dew/hoarfrost wascollected by means of insulated plain passive radiative condensersat three sites: AN and AS located in the close vicinity of themotorway (30 m) on the opposite sides of the road,...
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Concentrations of monoaromatic hydrocarbons in the air of the underground car park and individual garages attached to residential buildings
PublicationThe paper describes the characteristics of a two-level underground car park and three individual garages attached to residential buildings, differing by the resident utilization habits, located in North Poland (Tri-City agglomeration area). The strategy of collecting the analyte samples from air in mentioned enclosed areas, concerning the determination of benzene, toluene, ethylbenzene, o-xylene and p,m-xylenes (BTEX) concentrations...
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Surface and Trapping Energies as Predictors for the Photocatalytic Degradation of Aromatic Organic Pollutants
PublicationIn this study, anatase samples enclosed by the majority of three different crystal facets {0 0 1}, {1 0 0}, and {1 0 1} were successfully synthesized. These materials were further studied toward photocatalytic degradation of phenol and toluene as model organic pollutants in water and gas phases. The obtained results were analyzed concerning their surface structure, reaction type, and surface development. Moreover, the regression...
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Bankruptcy system model and efficiency versus the entrepreneurship and innovation in selected European countries
Publicationmodel and its efficiency on the development of entrepreneurship and innovation in selected European countries and Turkey. This goal was achieved by examining the relationships between debtor-friendliness of the bankruptcy law model and its efficiency on one side and entrepreneurship and innovation on the other. The cross-sectional ANOVA test and OLS regression method were chosen as the research method. In order to verify the research...
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Investigation of natural frequencies of axially loaded thin-walled columns
PublicationThe paper deals with correlation between natural frequencies of two steel thin-walled columns and the corresponding applied load. The structures are made of cold-formed lipped channel sections. The columns lengths were assumed to follow two buckling patterns – global flexural and flexural-torsional buckling. In the thicker structure two material models were considered – linearly-elastic and elastic-perfectly plastic. Numerical...
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An extended basis inexact shift–invert Lanczos for the efficient solution of large-scale generalized eigenproblems
PublicationThis paper proposes a technique, based on the Inexact Shift–Invert Lanczos (ISIL) method with Inexact Jacobi Orthogonal Component Correction (IJOCC) refinement, and a preconditioned conjugate-gradient (PCG) linear solver with multilevel preconditioner, for finding several eigenvalues for generalized symmetric eigenproblems. Several eigenvalues are found by constructing (with the ISIL process) an extended projection basis. Presented...
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Improvement of ships seakeeping performance by application of the full-scale cfd simulations
PublicationThe ship’s fuel economy is increasingly important. The paper presents the effect of redesigning a case study ship for increasing seakeeping performance. Selected wave parameters reflect very difficult operational conditions existing on the North Sea and the Baltic Sea. The analyzed variants of a case study ship represent the latest developments of modern hull forms. The concepts similar to V-shaped bulbous bow, X-bow, X-aft, B-bow...
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Stability and load bearing capacity of a truss with elastic braces
PublicationThe present paper is devoted to the numerical and experimental investigations of stability of a truss stiffened by elastic braces. The model of a real roof truss scaled by factor ¼ was investigated. In the research the linear buckling and non-linear static analysis of the truss shell and beam model with geometric and material non-linearity is presented. The initial imperfections were assumed in the form of the first buckling mode....
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Data-driven models for fault detection using kernel pca:a water distribution system case study
PublicationKernel Principal Component Analysis (KPCA), an example of machine learning, can be considered a non-linear extension of the PCA method. While various applications of KPCA are known, this paper explores the possibility to use it for building a data-driven model of a non-linear system-the water distribution system of the Chojnice town (Poland). This model is utilised for fault detection with the emphasis on water leakage detection....
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Monetary values estimates of solvents emissions
PublicationThe impact values for environmental emissions of 52 solvents are estimated and expressed in monetary units. The impact values of solvents present in the air are calculated on the basis of 13 impact indicators and for solvents present in water on additional 2 impact indicators. These impact values are weighted with the results obtained with multi-compartment distribution model, allowing to calculate the fraction of solvent emitted...
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Strain sequence effect on fatigue life and fracture surface topography of 7075-T651 aluminium alloy
PublicationThe paper studies the effect of strain-loading sequence on fatigue lifetime and fracture surface topographies in 7075-T651 aluminum alloy specimens. Fatigue tests were performed in two ways: (i) constant-amplitude loading and (ii) two series of variable amplitude loading with non-zero mean strain values. The topography of the fatigue fractures was measured over their entire surfaces with the help of an optical confocal measurement...
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Eventual Convergence of the Reputation-Based Algorithm in IoT Sensor Networks
PublicationUncertainty in dense heterogeneous IoT sensor networks can be decreased by applying reputation-inspired algorithms, such as the EWMA (Exponentially Weighted Moving Average) algorithm, which is widely used in social networks. Despite its popularity, the eventual convergence of this algorithm for the purpose of IoT networks has not been widely studied, and results of simulations are often taken in lieu of the more rigorous proof....
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Detection of debonding in adhesive joints using Lamb wave propagation
PublicationAdhesively bonded joints are widely used in many branches of industry. Mechanical degradation of this type of connections does not have significant symptoms that can be noticed during visual assessment, so non-destructive testing becomes a very important issue. The paper deals with experimental investigations of adhesively bonded steel plates with different defects. Five samples (an intact one and four with damages in the form...
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Partial dominated schedules and minimizing the total completion time of deteriorating jobs
PublicationA problem of scheduling deteriorating jobs on a single processor is considered. The processing time of a job is given by a function pi=ai+bisi, where si is the starting time of the job, ai>=0, bi>=0, for i=1,...,n. Jobs are non-preemptive and independent and there are neither ready times nor deadlines. The goal is to minimize the total weighted completion time. We show how to employ the concept of non-dominated schedules to construct...
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Sustainable development requires risky decisions - problematic 300 ton overweight transport passing a bridge
PublicationOversize load passages over bridges are one of the research issues related to sustainable development that engineering and scientific teams around the world have to deal with . The article presents the scope of activities that enabled the passage of an oversized vehicle with a total weight of over 300 tons over a reinforced concrete slab. The bridge load capacity is 30 tons. In order to assess the capacity of the bridge, detailed...
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Applications of Tensor Analysis in Continuum Mechanics
PublicationA tensor field is a tensor-valued function of position in space. The use of tensor fields allows us to present physical laws in a clear, compact form. A byproduct is a set of simple and clear rules for the representation of vector differential operators such as gradient, divergence, and Laplacian in curvilinear coordinate systems. The tensorial nature of a quantity permits us to formulate transformation rules for its components...
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PI observer stability and application in an induction motor control system
PublicationThe paper discusses the problem of stability of a proportional-integral Luenberger observer, designated for the state variables reconstruction of a linear, time-invariant dynamical system.
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Corporate social responsibility and project management: towards a better understanding of their relationship
PublicationThe main purpose of this article is to identify the fields of convergence, if any, between two management concepts and business practices, namely Corporate Social Responsibility (CSR) and Project Management (PM). To achieve the formulated goal, a systematic literature review (SLR), including bibliometric analysis, LOESS regression analysis, and text mining, was performed. This analysis allowed us to distinguish five categories...
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Cryptocurrencies as a speculative asset. How much uncertainty is included in cryptocurrency price?
PublicationThe aim of this paper is to examine the relationship between uncertainty indices (Geopolitical Uncertainty Index and Global Economic Policy Uncertainty Index) and cryptocurrencies. In order to conduct research, the authors collected the data on the major cryptocurrencies (Bitcoin, Ethereum, Tether, Dogecoin and USD coin) which account for 78% of the total market cap. Using panel OLS regression, this study finds that Bitcoin...
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Improvement of ships seakeeping performance by application of the Full-scale CFD simulations – case study
PublicationThe ship’s fuel economy is increasingly important. The paper presents the effect of redesigning a case study ship for increasing seakeeping performance. Selected wave parameters reflects very difficult operational con-ditions existing on the North Sea and the Baltic Sea. The analyzed variants of a case study ship represent the latest developments of modern hull forms. The concepts similar to V-shaped bulbous bow, X-bow, X-aft,...
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NON-LINE ANALYSIS OF STIFFNESS IN COMPRESSION CONDITIONS
PublicationThe analyzes were aimed at demonstrating the influence of parameters describing the deformation of the structure on the uncertainty of critical force, and the impact of technological imperfections on stress uncertainty in compression conditions. In a linear buckling analysis, the problem is considered only for the initial, permanent state of the stiffness matrix. In the case of demonstrating the influence of initial deformations...
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Analiza temperatury ekwiwalentnej do projektowania nawierzchni asfaltowych w Polsce z wykorzystaniem metody AASHTO 2004
PublicationW artykule przedstawiono analizę temperatury ekwiwalentnej obliczanej w oparciu o kryterium spękań zmęczeniowych warstw asfaltowych z metody AASHTO 2004 oraz kryterium deformacji strukturalnych Instytutu Asfaltowego. Do obliczeń przyjęto konstrukcję nawierzchni KR5 oraz wykorzystano dane temperaturowe z 50 stacji meteorologicznych z okresu 30 lat od roku 1989 do roku 2019 włącznie udostępnione przez Instytut Meteorologii i Gospodarki...
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Distance measurement errors in silent FM-CW sonar with matched filtering
PublicationThe secretiveness of sonar operation can be achieved by using continuous frequency-modulated sounding signalswith reduced power and significantly prolonged repeat time. The application of matched filtration in the sonarreceiver provides optimal conditions for detection against the background of white noise and reverberation, and avery good resolution of distance measurements of motionless targets. The article shows that target...
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Polypyrrole based gas sensor for ammonia detection
PublicationThe 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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Analysis of sloping brace stiffness influence on stability and load bearing capacity of a truss
PublicationThe paper is focused on the numerical study of stability and load bearing capacity of a truss with side elastic braces. The structure is made in reality. The rotational and sliding brace stiffnesses were taken into account. Linear buckling analysis and non-linear static analysis with geometric and material nonlinearity were performed for the beam and shell model of the truss with respect to the angle of sloping braces. As a result...
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Stability of an imperfect truss loaded by wind
PublicationThe present paper is devoted to the numerical research of stability of a truss loaded by wind and stiffened by elastic supports located at the top chord. The lateral braces or lateral and torsional braces were taken into account. In this paper, the linear buckling analysis re- sults for the beam and shell model were presented. Two different shapes of initial geometric imperfections were considered in the non-linear static analysis...
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Silver complexes stabilized by large silanethiolate ligands – crystal structures and luminescence properties
PublicationBulky silanethiolate and disiladithiolate ligands were applied to synthesize one mononuclear and three trinuclear silver complexes including two cyclic “microclusters” and a linear tri-nuclear silanethiolate complex. All obtained compounds are characterized by X-ray diffraction and FT-IR. NMR and emission spectroscopies were used where possible. The first trinuclear anionic silver thiolate is structurally characterized. The influence...
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Scheduling of compatible jobs on parallel machines
PublicationThe dissertation discusses the problems of scheduling compatible jobs on parallel machines. Some jobs are incompatible, which is modeled as a binary relation on the set of jobs; the relation is often modeled by an incompatibility graph. We consider two models of machines. The first model, more emphasized in the thesis, is a classical model of scheduling, where each machine does one job at time. The second one is a model of p-batching...
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Fundamentals of classical and analytical mechanics
PublicationThe book is a monographic description of the present attempt to Newtonian and Lagrangian mechanics. But also, it could be found as a supplementary educational material useful for the graduate courses in mechanics taken by students majoring in mechanical engineering, physics or physical science. In the book you can find a brief introduction to concepts and principles of algebra of vectors; Kinematics of particles, mainly focused...
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When Neural Networks Meet Decisional DNA: A Promising New Perspective for Knowledge Representation and Sharing
PublicationABSTRACT In this article, we introduce a novel concept combining neural network technology and Decisional DNA for knowledge representation and sharing. Instead of using traditional machine learning and knowledge discovery methods, this approach explores the way of knowledge extraction through deep learning processes based on a domain’s past decisional events captured by Decisional DNA. We compare our approach with kNN (k-nearest...
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Estimating the Impact of Globalization on International Competitiveneess : a Multidimensional Approach
PublicationThis paper examines the effects of globalization on international competitiveness (IC). The aggregated and disaggregated indices of IC (World Economic Forum) and globalization (KOF) for 132 countries in 2008 are used for the estimation of regression functions. The results show that globalization positively influences IC at the highest aggregation levels of the indices used. Social and political globalization affect IC at intermediate...
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Mass spectrometry based identification of geometric isomers during metabolic stability study of a new cytotoxic sulfonamide derivatives supported by quantitative structure-retention relationships
PublicationA set of 15 new sulphonamide derivatives, presenting antitumor activity have been subjected to a metabolic stability study. The results showed that besides products of biotransformation, some additional peaks occurred in chromatograms. Tandem mass spectrometry revealed the same mass and fragmentation pathway, suggesting that geometric isomerization occurred. Thus, to support this hypothesis, quantitative structure-retention relationships...
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Prediction of Overall In Vitro Microsomal Stability of Drug Candidates Based on Molecular Modeling and Support Vector Machines. Case Study of Novel Arylpiperazines Derivatives
PublicationOther than efficacy of interaction with the molecular target, metabolic stability is the primary factor responsible for the failure or success of a compound in the drug development pipeline. The ideal drug candidate should be stable enough to reach its therapeutic site of action. Despite many recent excellent achievements in the field of computational methods supporting drug metabolism studies, a well-recognized procedure to model...
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Effective Air Quality Prediction Using Reinforced Swarm Optimization and Bi-Directional Gated Recurrent Unit
PublicationIn the present scenario, air quality prediction (AQP) is a complex task due to high variability, volatility, and dynamic nature in space and time of particulates and pollutants. Recently, several nations have had poor air quality due to the high emission of particulate matter (PM2.5) that affects human health conditions, especially in urban areas. In this research, a new optimization-based regression model was implemented for effective...
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Heavy Duty Vehicle Fuel Consumption Modelling Based on Exploitation Data by Using Artificial Neural Networks
PublicationOne of the ways to improve the fuel economy of heavy duty trucks is to operate the combustion engine in its most efficient operating points. To do that, a mathematical model of the engine is required, which shows the relations between engine speed, torque and fuel consumption in transient states. In this paper, easy accessible exploitation data collected via CAN bus of the heavy duty truck were used to obtain a model of a diesel...
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Variable Data Structures and Customized Deep Learning Surrogates for Computationally Efficient and Reliable Characterization of Buried Objects
PublicationIn this study, in order to characterize the buried object via deep-learning-based surrogate modeling approach, 3-D full-wave electromagnetic simulations of a GPR model has been used. The task is to predict simultaneously and independent of each characteristic parameters of a buried object of several radii at different positions (depth and lateral position) in various dispersive subsurface media. This study has analyzed variable...
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The Method of Multi-criteria Analysis to Support the Decision on Load or Micro-generation Connection to a Low- or Medium-voltage Power Grid
PublicationThis paper presents a method that supports the decision in terms on selecting the best option of a load connection to a low- or medium-voltage power distribution grid, and of a micro-generation source connection to a low-voltage grid. The method is based on the search for the option with the lowest aggregate assessment measure, which is the weighted average of partial assessment measures determined for each of eight considered...
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Damage imaging algorithm for non-destructive inspection of CFRP/steel adhesive joints based on ultrasonic guided wave propagation
PublicationThe paper concerns assessing the quality of the adhesive connection between a steel plate and the reinforcing CFRP laminate. A three-stage algorithm for non-destructive damage imaging was developed. As the first step, an initial study involving dispersion curves of joint components was executed to determine the material parameters and the appropriate excitation frequency. During the second step, damage identification in three-layer...