Filtry
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Wyniki wyszukiwania dla: complex root
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The fracture behaviour of notched PMMA specimens under simple loading conditions – Tension and torsion experimental tests
PublikacjaThis paper presents the results of experimental testing of flat PMMA specimens during uniaxial loading conditions. Two separate tests were conducted: tensile and torsion. The specimens were weakened with V-type edge notches with different root radii: 0.5; 2 and 10 mm. The specimens were made in two thickness variants: 5 and 15 mm. Monotonic tensile and torsion tests were carried out while keeping the averaged strain rate constant,...
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Teratomas of Drosera capensis var. alba as a source of naphthoquinone: ramentaceone
PublikacjaPlants belonging to genus Drosera (family Droseraceae) contain pharmacologically active naphthoquinones such as ramentaceone and plumbagin. Hairy root cultures obtained following Agrobacterium rhizogenes-mediated transformation have been reported to produce elevated levels of secondary compounds as well as exhibit desirable rapid biomass accumulation in comparison to untransformed plants. The aim of this study was to establish...
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Melody Harmonization with Interpolated Probabilistic Models
PublikacjaMost melody harmonization systems use the generative hidden Markov model (HMM), which model the relation between the hidden chords and the observed melody. Relations to other variables, such as the tonality or the metric structure, are handled by training multiple HMMs or are ignored. In this paper, we propose a discriminative means of combining multiple probabilistic models of various musical variables by means of model interpolation....
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RECSYS CHALLENGE 2015: a BUY EVENT PREDICTION IN THE E-COMMERCE DOMAIN
PublikacjaIn this paper we present our approach to RecSys Challenge 2015. Given a set of e-commerce events, the task is to predict whether a user will buy something in the current session and, if yes, which of the item will be bought. We show that the data preparation and enrichment are very important in finding the solution for the challenge and that simple ideas and intuitions could lead to satisfactory results. We also show that simple...
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Role of Silicon in Counteracting Cadmium Stress in Pea Plants (Pisum sativum L.): Insights Into Cadmium Binding Mechanisms and Pectin Methylesterase Activity
PublikacjaPurpose: The aim of this study was to investigate the role of silicon (Si) in counteracting a cadmium (Cd) stress to pea plants (Pisum sativum L.) and to identify the mechanism by which Cd is bound within pea roots. Methods: These goals were achieved through (i) a histochemical study of Cd localization in pea roots, (ii) spectrophotometric determination of pectin content and the activity...
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The experimental and numerical investigation of fracture behaviour in PMMA notched specimens under biaxial loading conditions – Tension with torsion
PublikacjaThis paper presents the results of experimental fracture test of flat PMMA specimens under biaxial loading condition tension with torsion (proportional). The specimens were made in two thicknesses: 5 and 15 mm and were weakened with V-type edge notches with different root radii: 0.5; 2 and 10 mm. Thanks to the ARAMIS 3D 4 M non-contact vision system, measurement of the elongation and twist angle were recorded. During experimental...
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The correlation of fractal dimension to fracture surface slope for fatigue crack initiation analysis under bending-torsion loading in high-strength steels
PublikacjaIn this study, the fractal dimension of fatigue fracture surfaces is investigated in order to find an alternative failure loading indicator. Some of many metrological factors are generalized by reducing the fracture surface structure to one factor and develop an entire fracture surface procedure by analyzing the impact of surface slope and calculation resolution. Three notched geometries are studied under cyclic bending-torsion:...
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RMS-based damage detection in reinforced concrete beams: numerical simulations
PublikacjaImage-based damage detection methods using guided waves are well known and widely applied approaches in structural diagnostics. They are usually utilized in detection of surface damages or defects of plate-like structures. The article presents results of the study of applicability of imaging wave-based methods in detection in miniscule internal damage in the form of debonding. The investigations were carried out on numerical models...
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System Loss Model for Body-to-Body Networks in Indoor and Outdoor Environments
PublikacjaA system loss model for body-to-body networks in indoor and outdoor environments is proposed in this paper, based on measurements taken at 2.45 GHz. The influence of the type of environment, antenna visibility and user mobility on model parameters has been investigated. A significant impact of mutual antennas’ placement and their visibility is shown. The proposed model fits well to empirical data, with the average root mean square...
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Fracture prediction in flat PMMA notched specimens under tension - effectiveness of the equivalent material concept and fictitious material concept
PublikacjaThe fracture of notched elements under mode I loading (tension) remains an inexhaustible research topic, especially when it comes to the fracture of thermoplastic materials such as polymethylmethacrylate (PMMA), which experience considerable plastic strains under tension. The paper points out that traditional brittle fracture criteria such as mean stress (MS) or maximum tangential stress (MTS) criteria used to predict this phenomenon do...
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Elucidation of chemical compounds in different extracts of two Lavandula taxa and their biological potentials: Walking with versatile agents on the road from nature to functional applications
PublikacjaDue to their health-promoting and nutraceutical properties, lavenders are frequently employed in the food and pharmaceutical industries. Here, we focused on investigate the chemical profile of hexane, MeOH, and water extracts of leaf, flower, and root of L. pedunculata and L. stoechas and to assess their antioxidant, enzyme inhibitory, and antibacterial properties. The highest total polyphenolic and flavonoids contents were recorded...
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Experiment-aided virtual prototyping to minimize tool-workpiece vibration during boring of large-sized structures
PublikacjaThe paper presents the author's method of solving the problems of vi-bration suppression during boring of large-sized workpieces by means of an in-novative method of adjusting the rotational speed of the boring bar. It consists in selecting the spindle speed in accordance with the results of the cutting process simulation. The method includes identification of the model of the finite element method of the boring bar. The Root Mean...
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Price convergence in the European Union and in the new member states
PublikacjaThis paper examines price dispersion in the European Union (EU15) and in three New Member States (Poland, Hungary and the Czech Republic) between 1995 and 2006. The analysis utilizes both disaggregate and aggregate price data, including the prices of 157 products and two indices constructed using two different weighting procedures. For each category of goods the price dispersion is lower in EU15 than EU15 plus 3 NMS. Sigma convergence...
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The Use of Vegetables in the Biomonitoring of Cadmium and Lead Pollution in the Environment
PublikacjaLead and cadmium emitted from various anthropogenic sources have the ability to accumulate in tissues of living organisms. The phenomenon of accumulation of metals in the body is harmful and undesirable. On the other hand, the ability of plants to accumulate heavy metals from the individual elements of the environment has been used in biomonitoring of pollution. Leaf and root of vegetables have particular predisposition for accumulating...
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On the Usefulness of the Generalised Additive Model for Mean Path Loss Estimation in Body Area Networks
PublikacjaIn this article, the usefulness of the Generalised Additive Model for mean path loss estimation in Body Area Networks is investigated. The research concerns a narrow-band indoor off-body network operating at 2.45 GHz, being based on measurements performed with four different users. The mean path loss is modelled as a sum of four components that depend on path length, antenna orientation angle, absolute difference between transmitting...
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Uptake, accumulation, and translocation of Zn, Cu, Pb, Cd, Ni, and Cr by P. australis seedlings in an urban dredged sediment mesocosm: impact of seedling origin and initial trace metal content
PublikacjaThe study presents results from 6 months of phytoremediation of sediments dredged from three urban retention tanks carried out in a mesocosm setup with the use of P. australis. Two kinds of P. australis seedlings were considered: seedlings originating from natural (uncontaminated - Suncont) and anthropogenically changed environments (contaminated – Scont); this distinction was reflected in the baseline concentrations of trace metals...
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G2DC-PL+: a gridded 2 km daily climate dataset for the union of the Polish territory and the Vistula and Odra basins
PublikacjaG2DC-PL+, a gridded 2 km daily climate dataset for the union of the Polish territory and the Vistula and Odra basins, is an update and extension of the CHASE-PL Forcing Data – Gridded Daily Precipitation and Temperature Dataset – 5 km (CPLFD-GDPT5). The latter was the first publicly available, high-resolution climate forcing dataset in Poland, used for a range of purposes including hydrological modelling and bias correction of...
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Heavy metal accumulation and distribution in Phragmites australis seedlings tissues originating from natural and urban catchment
PublikacjaThe retention of heavy metal (HM) was studied in root and rhizomes (BLG), stems (ST), and leaves (LF) of Phragmites australis (common reed) seedlings collected from different locations, differing in the scale of anthropogenic interference. The analysis includes the reference samples of sediments in uncontaminated lake Garczonki and contaminated roadside ditch in Cieplewo. The concentrations of Zn, Cu, Pb, Cd, Ni, and Cr were analyzed...
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An Empirical System Loss Model for Body Area Networks in a Passenger Ferry Environment
PublikacjaThis paper presents a general empirical system loss model for estimating propagation loss in Body Area Networks in off-body communications at 2.45 GHz in a passenger ferry environment. The model is based on measurements, which were carried out in dynamic scenarios in the discotheque passenger ferry environment. The model consists of three components: mean system loss, attenuation resulting from the variable antenna position on...
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An Empirical System Loss Model for Body Area Networks in a Passenger Ferry Environment
PublikacjaThis paper presents a general empirical system loss model for estimating propagation loss in Body Area Networks in off-body communications at 2.45 GHz in a passenger ferry environment. The model is based on measurements, which were carried out in dynamic scenarios in the discotheque passenger ferry environment. The model consists of three components: mean system loss, attenuation resulting from the variable antenna position on...
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Comparison of the Effectiveness of Health Systems in The European Countries-Two-Stage DEA Model
PublikacjaThis article compares the efficiency of health systems in selected European countries using two-stage data envelopment analysis (DEA), based on data from the EUROSTAT database. In the first step, DEA efficiency scores were calculated for health care systems and, subsequently, the external variables describing lifestyle were used to calculate the truncated regression. Health care resources (physicians, nurses, hospital beds, financial...
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A method of predicting the best conditions for large-size workpiece clamping to reduce vibration in the face milling process
PublikacjaThe paper presents an innovative method of solving the problem of vibration suppression during milling of large-size details. It consists in searching for the best conditions for clamping the workpiece based on a rapid modal identification of the dominant natural frequencies only and requires repetitive changes in the tightening torque of the clamping screws. Then, by estimating the minimum work of the cutting forces acting in...
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Fracture surface topography investigation and fatigue life assessment of notched austenitic steel specimens
PublikacjaThe objectives of this study were to investigate the fracture surface topography of X8CrNiS18-9 austenitic stainless-steel specimens for different loadings and notch radii and to supplement the knowledge about the fracture mechanisms for fatigue performance. Cases with three different values of the notch radius ρ and the stress amplitude σa were analysed. The fracture topographies were quantified by the areas over their entire...
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Optimization of the spindle speed during milling of large-sized structures with the use of technique of Experiment-Aided Virtual Prototyping
PublikacjaIn the paper are presented considerations concerning vibration suppression problems during milling of large-sized workpieces with the use of innovative method of matching the spindle speed of cutting tool. It depends on repeatable change of the spindle speed value as soon as the optimal vibration state of the workpiece approaches. The values of dominant “peaks” in the frequency spectra and the Root Mean Square (RMS) values of time...
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Numerical Model of the Aortic Valve Implanted Within Real Human Aorta
PublikacjaCardiovascular system diseases are the main cause of deaths in developed and developing countries. The main reasons are myocardial infarction, heart failure, stroke and valvular diseases. These are caused mainly by arteriosclerosis. The valvular diseases involve a significant burden for the health care system and their frequency is rising with the patient age. This work describes the tools and numerical models appropriate for modeling...
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Detection of debonding in adhesive joints using Lamb wave propagation
PublikacjaAdhesively 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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Performance Evaluation of GAM in Off-Body Path Loss Modelling for Body Area Networks
PublikacjaThis paper addresses the performance evaluation of an off-body path loss model, based on measurements at 2.45 GHz, which has been developed with the use of the Generalised Additive Model, allowing to model a non-linear dependence on different predictor variables. The model formulates path loss as a function of distance, antennas’ heights, antenna orientation angle and polarisation, results showing that performance is very sensitive...
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NLP Questions Answering Using DBpedia and YAGO
PublikacjaIn this paper, we present results of employing DBpedia and YAGO as lexical databases for answering questions formulated in the natural language. The proposed solution has been evaluated for answering class 1 and class 2 questions (out of 5 classes defined by Moldovan for TREC conference). Our method uses dependency trees generated from the user query. The trees are browsed for paths leading from the root of the tree to the question...
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POSSIBILITY OF IDENTIFICATION OF TECHNICAL CONDITION OF BEARINGS FOR SELF-IGNITION ENGINES BY APPLICATION OF ACOUSTIC EMISSION AS A DIAGNOSTIC SIGNAL
PublikacjaThis paper presents the results of empirical studies where the acoustic emission (AE) method was applied to identify the technical condition of sliding surfaces of main and crank bearings for main diesel engines. The test results indicate that the measurements of the AE parameters allow the technical condition identification for bearings of this type. The results refer to the measurements of the parameters for AE generated in the...
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EVALUATION OF THE SEMIVARIOGRAM SELECTION ON THE KRIGING INTERPOLATION
PublikacjaThe aim of the paper is to present the possibilities of geostatistical interpolation kriging method using in the process of generating digital terrain models (DTM). The source of data is a direct measurements realized with a precision GNSS positioning kinematic measurement technique RTN. Kriging algorithm was analysed, especially in the meaning of a semivariogram every step. Theoretical semivariogram selection influence on the...
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Determination of Odour Interactions of Three-Component Gas Mixtures Using an Electronic Nose
PublikacjaThe paper presents an application of an electronic nose prototype comprised of six TGS-type sensors and one PID-type sensor to identify odour interaction phenomena in odorous three-component mixtures. The investigation encompassed eight odorous mixtures—toluene-acetone-triethylamine and formaldehyde-butyric acid-pinene — characterized by different odour intensity and hedonic tone. A principal component regression (PCR) calibration...
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DBpedia and YAGO Based System for Answering Questions in Natural Language
PublikacjaIn this paper we propose a method for answering class 1 and class 2 questions (out of 5 classes defined by Moldovan for TREC conference) based on DBpedia and YAGO. Our method is based on generating dependency trees for the query. In the dependency tree we look for paths leading from the root to the named entity of interest. These paths (referenced further as fibers) are candidates for representation of actual user intention. The...
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FEM modelling of stress and strain distribution in weld joints of steel sandwich panels
PublikacjaThe development of laser welding technology has enabled the mass production of thin-walled structures, including steel sandwich panels. The technology of joining plating panels with stiffeners by welding allows us to create joints with a specific geometry and material properties. In comparison with other types of joints, laser welds are characterized by their specific behaviour under cyclic load and, as a consequence, a different...
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Lamb wave-based monitoring of shear failure of an adhesive lap joint
PublikacjaThe paper presents a study on the elastic wave propagation in adhesive joints of steel plates subjected to tensile loading. A single lap joint was chosen for analysis because of its simplicity and plurality of applications. Experimental investigations consisted of the uniaxial extension of prepared specimens. Force and displacement values were recorded by a testing machine. Simultaneously, guided Lamb waves were excited and signals...
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The clamping selection method to reduce the vibration of large-size workpieces during the face milling process
PublikacjaThe article introduces a method for selecting the best clamping conditions to obtain vibration reduction during milling of large-size workpiece. It is based on experimental modal analysis performed for a set of assumed, fixing conditions of a considered workpiece to identify Frequency Response Functions (FRFs) for each tightening torque of the mounting screws. Simulated plots of periodically changing nominal cutting forces are...
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The elasto-plastic numerical study of crack initiation in notched PMMA specimens under uniaxial loading conditions – Tension and torsion
PublikacjaThis paper presents the results of FEM numerical calculations aimed at describing the plastic strain and stress fields under critical loading conditions: tensile force or torsional moment. The calculations were carried out with reference to the results of experimental tensile and torsional tests of flat PMMA specimens weakened with V-notches of different root radii: 0.5, 2 and 10 mm. The procedure for conducting nonlinear numerical...
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Fractographic-fractal dimension correlation with crack initiation and fatigue life for notched aluminium alloys under bending load
PublikacjaIn this study, fatigue fracture surfaces of aluminium alloy 2017-T4 notched specimens were investigated under cyclic bending to find an alternative failure loading index.. The surface topographies were measured on the entire fracture area with an optical profilometer for different loading conditions. Fatigue crack initiation life Ni and total fatigue life Nf were examined using standard surface topography parameters (such as, root...
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Collaborative Exploration of Trees by Energy-Constrained Mobile Robots
PublikacjaWe study the problem of exploration of a tree by mobile agents (robots) that have limited energy. The energy constraint bounds the number of edges that can be traversed by a single agent. We use a team of agents to collectively explore the tree and the objective is to minimize the size of this team. The agents start at a single node, the designated root of the tree and the height of the tree is assumed to be less than the energy...
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Estimation of respiration rate using an accelerometer and thermal camera in eGlasses
PublikacjaRespiration rate is a very important vital sign. Different methods of respiration rate measurement or estimation have been developed. However, especially interesting are those that enable remote and unobtrusive monitoring. In this study, we investigated the use of smart glasses for the estimation of respiration rate especially useful for indoors applications. Two methods were analyzed. The first one is based on measurements of...
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Chemometric Evaluation of WWTPs’ Wastewaters and Receiving Surface Waters in Bulgaria
PublikacjaWastewater treatment plant (WWTP) installations are designed and operated to reduce the quantity of pollutants emitted to surface waters receiving treated wastewaters. In this work, we used classical instrumental studies (to determine chemicals and parameters under obligations put with Directive 91/271/EEC), ecotoxicological tools (Sinapis alba root growth inhibition (SA-RG) and Heterocypris incongruens mortality (MORT) and growth...
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Damage imaging algorithm for non-destructive inspection of CFRP/steel adhesive joints based on ultrasonic guided wave propagation
PublikacjaThe 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...
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Industry 4.0 Implementation Challenges in Manufacturing Industries: an Interpretive Structural Modelling Approach
PublikacjaFor the last few years, the fourth industrial revolution, known as Industry 4.0, has been a hot topic among academics. Industry 4.0 literature involves researches presenting studies related to its different aspects including challenges, opportunities, implementation and adoption. However, a detailed study of challenges and barriers towards the Industry 4.0 implementation in manufacturing industries is missing. Hence, this paper...
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Vibration-Based Investigation of a Historic Bell Tower to Understand the Occurrence of Damage
PublikacjaABSTRACT The paper presents a survey of the historic Arch-cathedral bell tower in Vilnius induced by the appearance of cracks in the structure after a new bell system installation. An attempt is undertaken to identify the reason for the crack occurrence and to check a possible crack influence on global structural behaviour. The research is based on dynamic measurements made in the tower during ambient vibrations and during vibrations...
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Incremental construction of Minimal Tree Automata [online]
PublikacjaWe describe an algorithm that allows the incremental addition or removal of unranked ordered trees to minimal frontier-to-root deterministic tree automaton (DTA). The algorithm takes a tree t and a minimal DTA A as input; it outputs a minimal DTA A' which accepts the language L(A) accepted by A incremented (or decremented) with the tree t. The algorithm can be used to efficiently maintain dictionaries which store large collections...
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The Impact of Information and Communication Technology on the Rise of Urban Social Movements in Poland
PublikacjaThe chapter examines the relationship between the use of Information and Communications Technology (ITC) and the emergence of social movements focused on urban agenda in Poland. The aim is to investigate how and to what extent a growing body of smaller activist groups use opportunities provided by the ITC to achieve their political objectives. The research results indicate that Web-based media have helped to raise the profile...
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The Impact of Information and Communications Technology on the Rise of Urban Social Movements in Poland
PublikacjaThe chapter examines the relationship between the use of Information and Communications Technology (ITC) and the emergence of social movements focused on urban agenda in Poland. The aim is to investigate how and to what extent a growing body of smaller activist groups use opportunities provided by the ITC to achieve their political objectives. The research results indicate that Web-based media have helped to raise the profile of...
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STUDIES ON THE USE OF TERRESTRIAL LASER SCANNING IN THE MAINTENANCE OF BUILDINGS BELONGING TO THE CULTURAL HERITAGE
PublikacjaWithin the frames of the use of terrestrial laser scanning we find numerous examples of registration of building facilities, including also historical and valuable in their culture. In the case presented in this paper, at the root of the problem there is a preservation of the historic blacksmith’s forge located in Gdansk Orunia. The facility dating from the early nineteenth century was intended to repair involving the complete...
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Studies on the use of terrestrial laser scanning in the maintenance of buildings belonging to the cultural heritage
PublikacjaWithin the frames of the use of terrestrial laser scanning we find numerous examples of registration of building facilities, including also historical and valuable in their culture. In the case presented in this paper, at the root of the problem there is a preservation of the historic blacksmith's forge located in Gdansk Orunia. The facility dating from the early nineteenth century was intended to repair involving the complete...
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Impact of Tensile and Compressive Stress on Classical and Acoustic Barkhausen Effects in Grain-Oriented Electrical Steel
PublikacjaIn this paper, we present the results of the investigation of impact of tensile and compressive stress on the classical Barkhausen effect, magnetoacoustic emission (MAE) signal properties, and B(H) hysteresis loops for grain-oriented (GO) electrical steel. Samples have been glued to a nonmagnetic steel bar and stressed within elastic range (±800 μdef) by means of four-point bending method. The samples were cut out in two directions...
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Towards hand grip force assessment by using EMG estimators
PublikacjaThe purpose of this study was to propose a method to assess individual regression (calibration) curves to establish a relationship between an isometric grip force and surface electromyography (EMG) estimator. In this study 18 healthy volunteers (12 male (23.0 ± 2.0 years) and 6 female (23.2 ± 0.7 years)) had been examined. Ten EMG estimators (mean absolute value, root mean square, entropy, energy, turns per second, mean of zero...