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Search results for: TURBULENCE MODEL EVALUATION
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TOWARD A FUZZY MODEL OF POLISH INTERNET MORTGAGE MARKET
PublicationThis article presents our continuing efforts to develop a model of the Internet-based mortgage market in Poland. It sums up modeling research done over the last 4 years, also showing the stages and the process of building and verifying the proposed model consisting of three submodels. The submodels are described for three market situations; that is, a stable market, financial crisis, and economic boom. The proposed model variables...
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Neural Network Subgraphs Correlation with Trained Model Accuracy
PublicationNeural Architecture Search (NAS) is a computationally demanding process of finding optimal neural network architecture for a given task. Conceptually, NAS comprises applying a search strategy on a predefined search space accompanied by a performance evaluation method. The design of search space alone is expected to substantially impact NAS efficiency. We consider neural networks as graphs and find a correlation between the presence...
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Comparison of the measurement techniques employed for evaluation of ambient air odour quality
PublicationThe paper presents the results of investigation on ambient air odour quality in a vicinity of the industrial sewage treatment plant being a part of the crude oil processing plant. The investigation was performed during spring-winter season using a prototype of electronic nose and the Nasal Ranger field olfactometers. The prototype was equipped with a set of six semiconductor sensors by FIGARO Co. and one PID-type sensor. The field...
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Rapid Evaluation of Poultry Meat Shelf Life Using PTR-MS
PublicationThe use of proton transfer reaction mass spectrometry (PTR-MS) for freshness classification of chicken and turkey meat samples was investigated. A number of volatile organic compounds (VOCs) were selected based on the correlation (> 95%) of their concentration during storage at 4 °C over a period of 5 days with the results of the microbial analysis. In order to verify if the selected compounds are not sample-specific, a number...
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A model of ship propulsion systems operating process.
PublicationArtykuł zawiera opis formalny procesu eksploatacji układów napędowych statków. Model tego procesu został przedstawiony w formie dwuwymiarowego procesu,, którego współrzędnymi są procesy semi-Markowa o skończonych zbiorach stanów. Jeden z tych procesów jest procesem zmian stanów technicznych układów napędowych a drugi „ procesem zmian ich stanów eksploatacyjnych. Zaproponowano także jednowymiarowy model procesu eksploatacji układów...
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Adaptive CAD-Model Construction Schemes
PublicationTwo advanced surrogate model construction techniques are discussed in this paper. The models employ radial basis function (RBF)interpolation scheme or artificial neural networks (ANN) with a new training algorithm. Adaptive sampling technique is applied withrespect to all variables. Histograms showing the quality of the models are presented. While the quality of RBF models is satisfactory, theperformance of the ANN models obtained...
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Diagnostic Model of Crankshaft Seals
PublicationT he paper presents a research stand being a diagnostic model of radial lip seals used, among others, on crankshafts of piston combustion engines in order to identify the correctness of their operation. The possibility of determining the technical condition of lip seals on the basis of the proposed coefficient of correctness of operation has been described. T he basic features of seals influencing their correctness of...
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Nieliniowy model matematyczny transformatora trójfazowego = Non-linear mathematical model of a three-phase transformer
PublicationPrzedstawiono model transformatora trójfazowego o rdzeniu trójkolumnowym, który zawiera układ rów-nań opisujących obwód magnetyczny oraz oddzielnie układ równań obwodu elektrycznego. Wydzielenie re-luktancji elementów rdzenia umożliwia uwzględnienie zmian względnej przenikalności magnetycznej w funkcji bieżącej wartości strumienia w rdzeniu. Re-luktancje odpowiadające strumieniom rozproszenia obliczono wg zasad klasycznych. Funkcję...
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Stałoprądowy model tranzystora typu HSD MAGFET
PublicationZaproponowano stałoprądowy model dwudrenowego tranzystora polowego typu HSD MAGFET, wykorzystywanego jako czujnik pola magnetycznego o dużej czułości na zmiany pola magnetycznego i dużej geometrycznej rozdzielczości pomiarowej. Zaprezentowany model odzwierciedla zjawisko podziału prądu płynącego w kanale tranzystora na prądy drenów i uwzględnia wzajemne oddziaływanie napięć drenów VDS1 i VDS2 na prady drenów ID1 i ID2 poprzez wprowadzenie...
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Air flow phenomena in the model of the blind drift
PublicationIn the presented paper, Particle Image Velocimetry (PIV) has been used to investigate flow pattern and turbulent structure in the model of blind drift. The presented model exist in mining, and has been analyzed to resolve ventilation issues. Blind region is particularly susceptible to unsafe methane accumulation. The measurement system allows us to evaluate all components of the velocity vector in channel cross-section simultaneously....
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A decentralised model of the regulating ancillary services market
PublicationThe article presents a model of regulating ancillary services provision in a dencetralised manner. A concept of the operation of local markets for ancillary services is presented.
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Zdecentralizowany model rynku regulacyjnych usług systemowych
PublicationZaprezentowano model pozyskania regulacyjnych usług systemowych w sposób zdecentralizowany. Przedstawiono koncepcję funkcjonowania lokalnych rynków usług regulacyjnych.
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Experimental and numerical evaluation of mechanical behaviour of composite structural insulated panels
PublicationComposite structural insulated panels (CSIPs) are novel prefabricated elements for structural applications. Panels under consideration are made from glass-fibre reinforced magnesia cement boards as facesheets and expanded polystyrene foam (EPS) as a core. Quasi-static full-scale and model bending tests under monotonic loading were performed to recognize mechanical properties of CSIPs in flexure. In addition, tensile, compressive,...
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Conceptual fuzzy model of the polish internet mortgage market
PublicationThe aim of this paper is to present the conceptual structure of basic fuzzy model representing Polish Internet mortgage market. The paper starts with introduction describing the market complexities and challenges, and description of previously created rule based model. Then the steps of the process of proposed model fuzzyfication are presented. Final part of the paper consists of conclusions and directions for future research.
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Evaluation of the Commercial Electrochemical Gas Sensors for the Monitoring of CO in Ambient Air
PublicationAir pollution is a growing concern of civilized world, which has a significant impact on human health and the environment. Recent studies highlight that the exposure to polluted air can increase the incidence of diseases and deteriorate the quality of life. Hence, it is necessary to develop tools for real-time air quality monitoring. For air pollution monitoring a wide range of stationary gas and particulate analysers can be used....
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Design and Evaluation of the Platform for Weight-Shifting Exercises with Compensatory Forces Monitoring
PublicationDetails of a platform for the rehabilitation of people with severe balance impairment are discussed in the paper. Based upon a commercially available static parapodium, modified to fit force sensors, this device is designed to give a new, safe tool to physiotherapists. It is designed for the patients who cannot maintain equilibrium during a bipedal stance and need to hold to or lean on something during the rehabilitation. Visual,...
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Ella4Life virtual assistant - user centered design strategy - evaluation following labolatory tests
PublicationIn the paper, we summarize the evaluation of Anne4Care system after laboratory tests. A group of end users, seniors over 55 years of age, rated a virtual assistant by completing a questionnaire. The objectives of the pilot evaluations are mainly to assess the feasibility, usability, acceptance and functionality of the system and the ability of the potential target user to use the system and receive valuable information from it...
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Model osobistej wirtualnej biblioteki cyfrowej
PublicationSzybki rozwój Internetu umożliwiający publikowanie i czytanie artykułów online w skali globalnej, uzasadnia tworzenie bibliotek cyfrowych jako repozytoriów wiedzy. Ich rozwój napotyka jednak na liczne bariery natury psychologicznej, organizacyjnej i technologicznej. W artykule przedstawimy propozycje ich przełamania z punktu widzenia doświadczeń Biblioteki Głównej Politechniki Gdańskiej. W szczególności skoncentrujemy się na modelu...
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Hybrid Reduced Model of Continuous System
PublicationThe paper introduces an alternative method of modelling and modal reduction of continuous systems. Presented method is a hybrid one. It combines the advantages of modal decomposition method and the rigid finite element method. In the proposed method continuous structure is divided into one-dimensional continuous elements. For each 1D element modal decomposition and reduction is applied. Interactions between substructures are...
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Multisource model of ship electric field
PublicationA steel-hulled ship in sea water produces an electric field around itself. The source of this field are electrochemical processes and ship's cathodic protection. The analysis of the electric field around the ship is important by the reason of the ship's identification and counter-mine protection. The paper presents a simplified model of the ship's multisource electric field, which allows to calculate the electric field distribution...
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Nowy empiryczny model propagacjny RTK
PublicationW referacie opisano i przeanalizowano nowy model empiryczny do szacowania tłumienia propagacyjnego w ruchomych łączach radiowych pracujących w środowisku terminalu kontenerowego. Na wstępie opisane zostały badania pomiarowe przeprowadzone w celu uzyskania danych empirycznych pozwalających na opracowanie nowego modelu oraz scharakteryzowano badane środowisko. W głównej części referatu omówiono postać analityczną modelu oraz przedstawiono...
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Model tworzenia wartości w logistyce
PublicationWażnym zadaniem zarządzania logistycznego jest budowanie przewagi konkurencyjnej przedsiębiorstwa na bazie zdolności łańcucha dostaw (łańcucha logistycznego) do tworzenia wartości. Osiągnięcie oczekiwanego poziomu wzrostu wartości w procesach logistycznych wymaga połączenia wartości z użytecznością, szybkością działania i efektywnością kosztową. W pracy przedstawiono model procesu tworzenia wartości w działaniach logistycznych,...
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Information retrieval with semantic memory model
PublicationPsycholinguistic theories of semantic memory form the basis of understanding of natural language concepts. These theories are used here as an inspiration for implementing a computational model of semantic memory in the form of semantic network. Combining this network with a vector-based object-relation-feature value representation of concepts that includes also weights for confidence and support, allows for recognition of concepts...
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Model rozmyty zarządzania przedsięwzięciami informatycznymi.
PublicationPrzedstwiono budowę samonastrajalnego modelu rozmytego zarządzania przedsięwzięciami informatycznymi, który będzie wykorzystywany do wspomagania wytwarzania systemów opartych na wiedzy. Proponowany model bazuje on na rozwiązaniach opartych na wiedzy oraz teorii systemów dynamicznych i zbiorów rozmytych. W szczegółowej konstrukcji wykorzystano wiedzę dotyczącą zarządzania rzeczywistymi przedsięwzięciami informatycznymi (PATRIC i...
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Impedance spectra of RC model as a result of testing pulse excitation measurement method
Open Research DataThe impedance spectrum of RC model object obtained using pulse excitation EIS impedance spectrosocpy measurement method. The 1V voltage pulse excitation duration was set to 0.1s and the total acqusition time was set to 1000s. The object under test was built using RC components connected as Baunier model of anticorrosion coating with the following components...
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Three-dimensional conceptual model for service-oriented simulation
Publicationn this letter, we propose a novel three-dimensional conceptual model for an emerging service-oriented simulation paradigm. The model can be used as a guideline or an analytic means to find the potential and possible future directions of the current simulation frameworks. In particular, the model inspects the crossover between the disciplines of modeling and simulation, service-orientation, and software/systems engineering. Finally,...
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Computer System for Evaluation of Shock Hazard in Circuits with Non-sinusoidal Earth Currents
PublicationEffects of current on people are mainly considered for 50/60 Hz sinusoidal current and smooth direct current. However, modern low voltage circuits are very often equipped with power electronics converters – rectifiers, frequency converters, therefore non-sinusoidal earth currents (touch currents) occur. For non-sinusoidal currents safety criteria should be modified. This paper presents a computer system, based on LabVIEW environment,...
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A Numerical Model Study on Ice Boom in a Coastal Lake
PublicationA numerical study on the effectiveness of the proposed ice boom to be installed near the entrance of Lake Notoro, Hokkaido, Japan to prevent sea ice moving into the lake is presented. A two-dimensional hydro–ice dynamics model was modified to allow for the treatment of ice-boom interaction with the effect of tidal current. The numerical model is a coupled hydrodynamic and ice dynamic model. The ice dynamic component uses a Lagrangian...
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Practical Use of Generic IT Organization Evolution Model
PublicationIn the paper we analyze, basing on the practical experiences, how the Generic IT Organization Model could be used to describe evolution of real-world IT support organization in relation to IT Service Management area.
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Dietary behaviour and physical activity policies in Europe: learnings from the Policy Evaluation Network (PEN)
PublicationThe European Policy Evaluation Network (PEN), initiated in autumn 2018, aimed at advancing the evidence base for public policies impacting dietary behaviour, physical activity and sedentary behaviours in Europe. This is needed because non-communicable diseases—the leading cause of global mortality—are substantially caused by physical inactivity and unhealthy dietary behaviours, which in turn are driven by upstream factors that...
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Application of MARKAL model to optimisation of electricity generation structure in Poland in the long-term time horizon. Part II. Model and forecasts assumptions
PublicationIn this paper, the next in a series of publications on the subject, assumptions are presented of a power system development model in terms of electricity generation technology infrastructure in Poland, in the long term perspective until 2060. The model is based on the mathematical structure of the MARKAL optimization package. Among other things developed are a forecast of the final demand for electricity and heat, the current...
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A new diagnostic IR-thermal imaging method for evaluation of cardiosurgery procedures
PublicationTwo methods for monitoring the state of the myocardium during cardiosurgical interventions based on thermal IR imaging are presented below. These methods, called static thermography and active dynamic thermography (ADT), use information about the distribution of temperature on the surface, and an external excitation source to induce thermal transient processes in a tested object. Recording the time series of thermograms allows...
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In Situ Verification of Numerical Model of Water Hammer in Slurries
PublicationThis paper presents a numerical model of transient flow in a pressure slurry pipeline network with verification based on in situ measurements. The model, primarily verified in laboratory conditions, has been extended and applied to the case of a large and complex slurry pipeline network in Poland. In the model, the equivalent density concept was applied. In situ experiments were performed for various unsteady flow episodes, caused by...
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Normalized Partial Scattering Cross Section for Performance Evaluation of Low-Observability Scattering Structures
PublicationThe development of diffusion metasurfaces created new opportunities to elevate the stealthiness of combat aircraft. Despite the potential significance of metasurfaces, their rigorous design methodologies are still lacking, especially in the context of meticulous control over the scattering of electromagnetic (EM) waves through geometry parameter tuning. Another practical issue is insufficiency of the existing performance metrics,...
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Development and validation of lumbar spine finite element model
PublicationThe functional biomechanics of the lumbar spine have been better understood by finite element method (FEM) simulations. However, there are still areas where the behavior of soft tissues can be better modeled or described in a different way. The purpose of this research is to develop and validate a lumbar spine section intended for biomechanical research. A FE model of the 50th percentile adult male (AM) Total Human Model for Safety...
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A concept of heterogeneous numerical model of concrete for GPR simulations
PublicationThe Ground Penetrating Radar (GPR) method, which is increasingly being used in the non-destructive diagnostics of reinforced concrete structures, often needs more accurate interpretation tools for analysis of experimental data. Recently, there has been growing interest in developing of various numerical models for exhaustive understanding of GPR data. This paper presents the concept of a heterogeneous numerical model of concrete,...
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Efficiency Evaluation of High Performance Computing Systems Using Data Envelopment Analysis
PublicationThe paper presents an evaluation method of high performance computing (HPC) systems using multicriteria efficiency analysis. The Data Envelopment Analysis approach was applied and adapted to the specifics of HPC, which enabled us to compare relative efficiency of systems considering simultaneously multiple parameters. The analysis is based on the TOP500 list of world largest supercomputers and their parameters such as: the number...
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Dipolowy model pola elektrycznego okrętu
PublicationOkręt o kadłubie stalowym będący w wodzie morskiej wytwarza wokół siebie pole elektryczne. Źródłem tego pola są procesy elektrochemiczne i ochrona katodowa okrętu. Analiza pola elektrycznego wokół okrętu jest istotna z punktu widzenia identyfikacji oraz ochrony przeciwminowej. W pracy przedstawiono uproszczony model dipolowy pola magnetycznego okrętu, który pozwala na obliczenie rozkładu pola elektrycznego w tzw. strefie dalekiej...
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Spike patterns and chaos in a map-based neuron model
PublicationThe work studies the well-known map-based model of neuronal dynamics introduced in 2007 by Courbage, Nekorkin and Vdovin, important due to various medical applications. We also review and extend some of the existing results concerning β-transformations and (expanding) Lorenz mappings. Then we apply them for deducing important properties of spike-trains generated by the CNV model and explain their implications for neuron behaviour....
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Determination of Mathematical Model Parameters of a Medium Frequency Transformer
PublicationThe paper presents the results of experimental studies of the medium frequency transformer. The object of the research was a prototype of a single-phase transformer with a core made of ferrite I-core elements and windings made of Litz conductors. The research was carried out to determine the parameters of the transformer's mathematical model. The scope of the tests included determining the magnetic hysteresis loop and measuring...
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St. Adalberd church 3D point model
Open Research DataResearch data show the church of St. Adalbert in Gdansk, Poland. Two layers are presented in the .zip file: one represents the laser scanning result, the second represents the point cloud from 36 photogrammetry images from the UAV system. The aligned point clouds formed the basis to create the high-resolution 3D model. Reference data are laser scanning...
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Development and evaluation of RADA-PDGF2 self-assembling peptide hydrogel for enhanced skin wound healing
PublicationBackground: Wound healing complications affect numerous patients each year, creating significant economic and medical challenges. Currently, available methods are not fully effective in the treatment of chronic or complicated wounds; thus, new methods are constantly sought. Our previous studies showed that a peptide designated as PDGF2 derived from PDGF-BB could be a promising drug candidate for wound treatment and that RADA16-I...
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Evaluating Pornography Problems Due to Moral Incongruence Model
PublicationIntroduction To date, multiple models of problematic pornography use have been proposed, but attempts to validate them have been scarce. Aim In our study, we aimed to evaluate the Pornography Problems due to Moral Incongruence model proposing that self-appraisals of pornography addiction stem from (i) general dysregulation, (ii) habits of use, and (iii) moral incongruence between internalized norms and behavior. We investigated...
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Experimental and numerical investigations for GPR evaluation of reinforced concrete footbridge
PublicationThe GPR method has increasingly found application in non-destructive testing of reinforced concrete structures. This paper presents the new approach of modelling of the electromagnetic wave propagation for reinforced concrete structures with a complex system of the reinforcement. Simulations of the GPR field were performed on a three-dimensional model of a footbridge using the FDTD method. Numerical maps were compared with results...
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A hyperelastic model for soils with stress-induced and inherent anisotropy
PublicationIn this paper, modelling of the superposition of stress-induced and inherent anisotropy of soil small strain stiffness is8presented in the framework of hyperelasticity. A simple hyperelastic model, capable of reproducing variable stress-induced9anisotropy of stiffness, is extended by replacement of the stress invariant with mixed stress–microstructure invariant to10introduce constant inherent cross-anisotropic component. A convenient...
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Model hybrydowy układu wielowirnikowego z przekładnią
PublicationW pracy przedstawiono metodę redukcji modelu układu wielowirnikowego z przekładnią, w którym uwzględniono zmienną prędkość kątową wirników, oddziaływania żyroskopowe, nieproporcjonalne tłumienie oraz nieliniowość podatności zazębienia. Zaproponowano hybrydową metodę modelowania, w której zastosowano: dekompozycję modalną oraz dyskretyzację przestrzenną. Zredukowany model modalny zbudowano dla części rozważanego układu, w której...
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Chapter 11 – Application of Chemical Sensors and Sensor Matrixes to Air Quality Evaluation
PublicationIndoor and outdoor air quality is one of the key factors influencing human health. However, air quality evaluation is not easy task. Air is a complex system, which is subjected to changes even within short period of time. Progress in analytical methods and analytical tools provides increasingly more reliable information on the condition and quality of indoor and outdoor air. This progress, however, generates an increase in the...
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High-temperature Corrosion of ~ 30 Pct Porous FeCr Stainless Steels in Air: Long-Term Evaluation Up to Breakaway
PublicationIn this work, a long-term (up to 6000 hours) corrosion evaluation of three porous (~ 30 pct of initial porosity) ferritic iron-chromium alloys with different Cr contents (20, 22, and 27 wt pct of Cr) was carried out at 600 C, 700 C, 800 C, and 900 C in air. Mass gain measurements and SEM analyses revealed that at temperatures above 600 C, all alloys exhibit breakaway corrosion, whereas at 600 C, none of the alloys were heavily...
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Towards a Universal Model of Engineering Change Management
PublicationThe paper deals with the issue of engineering change management (ECM). ECM has received much less attention in the literature than general change management. Moreover, due to their specifics (complexity and multifaceted nature), hitherto developed ECM models are difficult to implement in companies. The paper aims to develop a simplified, universal, and hence easily applicable model of ECM. We based our assumptions on a case study...
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Depolarisation Model for a BAN Indoor Scenario
PublicationIn this paper, an analysis of depolarisation in Body Area Networks for Body-to-Infrastructure communications based on a measurement campaign in the 5.8 GHz band in an indoor environment is performed. Measurements were made with an offbody antenna transmitting linearly polarised signals and dualpolarised receiving antennas carried by the user on the body. A Normal Distribution with a mean of 2.0 dB and a standard deviation of 4.3...