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Search results for: SIR MODELS
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Early warning models against bankruptcy risk for Central European and Latin American enterprises
PublicationThis article is devoted to the issue of forecasting the bankruptcy risk of enterprises in Latin America and Central Europe. The author has used statistical and soft computing methods to program the prediction models. It compares the effectiveness of twelve different early warningmodels for forecasting the bankruptcy risk of companies. In the research conducted, the author used data on 185 companies listed on the Warsaw Stock Exchange...
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Chosen aspects of skeletal system modeling: Numerical solid and shell models of femur part
PublicationThe purpose of this paper is to present a new method of femur part modeling by using the finite element method. This method treats a femur part as a system composed of cortical and trabecular bone. For the purpose of determining a proper shape of femur part model there were created three models: a) the first one describes a femur part as a solid structure; b) the second one describes a femur part as a connection of cortical bone...
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Macro models of casualties in road transport. Modelowanie strat osobowych w transporcie drogowym.
PublicationW referacie przedstawiono propozycję makro modelu strat osobowych ponoszonych w wypadkach drogowych. Zaproponowano modele liczby ofiar śmiertelnych wypadków drogowych zbudowanych na bazie danych z kilkudziesięciu krajów całego świata. Przedstawione koncepcje budowy modeli mogą posłużyć do opracowania modeli czynnikowych opisujących strategiczne ryzyko społeczne na sieci dróg wybranych krajów z całego świata. jedną z koncepcji...
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Organizational culture and coopetition: An exploratory study of the features, models and role in the Polish Aviation Industry
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Prediction of Peptide Retention at Different HPLC Conditions from Multiple Linear Regression Models
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Integration and Visualization of the Results of Hydrodynamic Models in the Maritime Network-Centric GIS of Gulf of Gdansk
PublicationEnsuring of security in the coastal area makes on a seaside countries research in the field of infrastructure spatial information of environmental data. The paper presents the results of work on the construction of this infrastructure by integrating electronic navigational chart with ortophotomaps of coastal areas as well as numerical data from weather and hydrodynamic models. Paper focuses on a problems associated with creating...
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Expedited two-objective dimension scaling of compact microwave passives using surrogate models
PublicationGeometry scaling of compact microwave structures is a challenging problem because of complex relationships between the physical dimensions and electrical characteristics, mostly caused by considerable cross-couplings in densely arranged layouts. Here, a procedure for expedited dimension scaling of compact microwave couplers with respect to two independent criteria has been presented. Our approach involves inverse surrogate models...
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Fast EM-driven optimization using variable-fidelity EM models and adjoint sensitivities
PublicationA robust and computationally efficient technique for microwave design optimization is presented. Our approach exploits variable-fidelity electromagnetic (EM) simulation models and adjoint sensitivities. The low-fidelity EM model correction is realized by means of space mapping (SM). In the optimization process, the SM parameters are optimized together with the design itself, which allows us to keep the number...
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Experimental study on models of cylindrical steel tanks under mining tremors and moderate earthquakes
PublicationThe aim of the study is to show the results of complex shaking table experimental investigation focused on the response of two models of cylindrical steel tanks under mining tremors and moderate earthquakes, including the aspects of diagnosis of structural damage. Firstly, the impact and the sweep-sine tests have been carried out, so as to determine the dynamic properties of models filled with different levels of liquid. Then,...
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Rapid design optimization of antennas using variable-fidelity EM models and adjoint sensitivities
PublicationPurpose – Development of techniques for expedited design optimization of complex and numerically expensive electromagnetic (EM) simulation models of antenna structures validated both numerically and experimentally. The paper aims to discuss these issues. Design/methodology/approach – The optimization task is performed using a technique that combines gradient search with adjoint sensitivities, trust region framework, as well as...
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Theoretical and mathematical models of the torque of mechanical losses in a hydraulic rotational motor for hydrostatic drive
PublicationW pracy przedstawiono modele teoretyczne i matematyczne momentu strat mechanicznych występujących w silniku hydraulicznym obrotowym o stałej teoretycznej chłonności qMt silnika na obrót wału (o stałej teoretycznej objętości roboczej VMt silnika) i o zmiennej chłonności qMgv = bM qMt na obrót wału (o zmiennej geometrycznej objętości roboczej VMgv silnika). Modele mają służyć badaniom laboratoryjnym i symulacyjnym strat energetycznych...
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Correlation–polarization effects in electron/positron scattering from acetylene: A comparison of computational models
PublicationDifferent computational methods are employed to evaluate elastic (rotationally summed) integral and differential cross sections for low energy (below about 10 eV) positron scattering off gas-phase C2H2 molecules. The computations are carried out at the static and static-plus-polarization levels for describing the interaction forces and the correlation–polarization contributions are found to be an essential component for the correct...
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Aqueous solutions of NMA, Na2HPO4 , and NaH2PO4 as models for interaction studies in phosphate–protein systems
PublicationPhosphate buffers are essential for many areas of studies. However, their influence on buffered systems is often ignored. The phosphate salts can interact with biologically important macromolecules (e.g. proteins) and stabilize or destabilize them. With our research, we want to answer question what kind of interactions, if any, occur between phosphate ions and a protein backbone model — N-methylacetamide (NMA). ATR-FTIR spectroscopy...
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Selection of AHI + SC Hybrid Storage Based on Mathematical Models and Load Variation Characteristics
PublicationThe article deals with the design of a hybrid storage consisting of Aqueous Hybrid Ion battery (AHI) and supercapacitor (SC) modules. The selection of components is based on the knowledge of the load profile of the storage and the AHI battery and supercapacitor models. The paper presents the method of selecting components of the storage made of AHI batteries and supercapacitor modules The article includes an example of the hybrid...
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Efficient knowledge-based optimization of expensive computational models using adaptive response correction
PublicationComputer simulation has become an indispensable tool in engineering design as they allow an accurate evaluation of the system performance. This is critical in order to carry out the design process in a reliable manner without costly prototyping and physical measurements. However, high-fidelity computer simulations are computationally expensive. This turns to be a fundamental bottleneck when it comes to design automation using numerical...
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SCRAMBLE’N’GAMBLE: a tool for fast and facile generation of random data for statistical evaluation of QSAR models
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Semi-Markow Processes as Models of Devices´ Operating Process of Ship Pro-pulsion System
PublicationReferat zawiera formalny opis procesu eksploatacji urządzeń.
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Theoretical calculation of pKas of phosphoric (V) acidin the polarisable continuum and cluster-continuum models
PublicationW pracy oceniono dokładność modelu polaryzowalnego kontinuum (PCM) i mieszanego modelu klaster-kontinuum do przewidywania wartości trzech kolejnych stałych dysocjacji kwasu fosforowego (V). Obliczenia PCM na poziomie MP2/6-31+G(d,p) odtwarzają wartość pierwszego pKa z rozsądną niepewnością, jednak wartości kolejnych pKa obarczone są bardzo dużym błędem, nawet po podniesieniu poziomu teorii do metody zespolonej G3B3. Dopiero obliczenia...
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Optimization of briquetting technology of fine-grained metallurgical materials based on statistical models of compressibility
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Numerical analysis of settlement of a high-rise building using two constitutive soil models
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Optimizing Medical Personnel Speech Recognition Models Using Speech Synthesis and Reinforcement Learning
PublicationText-to-Speech synthesis (TTS) can be used to generate training data for building Automatic Speech Recognition models (ASR). Access to medical speech data is because it is sensitive data that is difficult to obtain for privacy reasons; TTS can help expand the data set. Speech can be synthesized by mimicking different accents, dialects, and speaking styles that may occur in a medical language. Reinforcement Learning (RL), in the...
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Adaptive Sampling for Non-intrusive Reduced Order Models Using Multi-Task Variance
PublicationNon-intrusive reduced order modeling methods (ROMs) have become increasingly popular for science and engineering applications such as predicting the field-based solutions for aerodynamic flows. A large sample size is, however, required to train the models for global accuracy. In this paper, a novel adaptive sampling strategy is introduced for these models that uses field-based uncertainty as a sampling metric. The strategy uses...
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Vessel Energy Requirement Prediction from Acceleration Stage Towing Tests on Scale Models
PublicationOne of the most crucial tasks for naval architects is computing the energy required to meet the ship’s operational needs. When predicting a ship’s energy requirements, a series of hull resistance tests on a scale model vessel is carried out in constant speed stages, while the acceleration stage measurements are ignored. Another important factor in seakeeping analysis is the ship’s hydrodynamic added mass. The second law of dynamics...
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Equivalent Single Layer Models in Free Vibration Analysis of Laminated Multi-Layered Plates
PublicationThe performance of selected equivalent single-layer (ESL) models is evaluated within several classical benchmark tests for small amplitude free vibration analysis of multi-layered plates. The authors elaborated their own Finite Element software based on the first-order shear deformation (FOSD) theory with some modifications incorporated including a correction of the transverse shear stiffness and an application of zigzag type functions....
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Public Perception of Digital Contact Tracing App and Implications for Technology Acceptance and Use Models
PublicationGovernments are increasingly adopting digital contact tracing applications (DCT) as a key component of their response to the COVID-19 pandemic. However, governments are struggling to achieve widespread adoption of DCT necessary for obtaining the expected individual and public benefits associated with its use. Consequently, studies on DCT have focused on the barriers to DCT adoption in different contexts and possible ways of overcoming...
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Comparison of Mathematical Models of Torque Transmitted by Multi-disc Wet Clutch with Experimental Results
PublicationIn this article was described the methodology for the experimental study of flows in the prototype of a satellite hydraulic motor with a rotating body. The experimental tests of the motor were carried out at a low constant rotational speed in a wide range of pressure drop in this motor. The constant rotational speed of the motor was kept by a worm gear. Based on the test results, the leakage characteristics in the flat gaps of...
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On Nature-Inspired Design Optimization of Antenna Structures Using Variable-Resolution EM Models
PublicationNumerical optimization has been ubiquitous in antenna design for over a decade or so. It is indispensable in handling of multiple geometry/material parameters, performance goals, and constraints. It is also challenging as it incurs significant CPU expenses, especially when the underlying computational model involves full-wave electromagnetic (EM) analysis. In most practical cases, the latter is imperative to ensure evaluation reliability....
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The Effect of the Selection of Three-Dimensional Random Numerical Soil Models on Strip Foundation Settlements
PublicationThis paper delivers a probabilistic attempt to prove that the selection of a random three-dimensional finite element (FE) model of a subsoil affects the computed settlements. Parametricanalysis of a random soil block is conducted, assuming a variable subsoil Young’s modulus inparticular finite elements. The modulus is represented by a random field or different-sized setsof random variables; in both cases, the same truncated...
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Design and Analysis of Artificial Neural Network (ANN) Models for Achieving Self-Sustainability in Sanitation
PublicationThe present study investigates the potential of using fecal ash as an adsorbent and demonstrates a self-sustaining, optimized approach for urea recovery from wastewater streams. Fecal ash was prepared by heating synthetic feces to 500 °C and then processing it as an adsorbent for urea adsorption from synthetic urine. Since this adsorption approach based on fecal ash is a promising alternative for wastewater treatment, it increases...
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Multiple jets impingement – numerical analysis by the ζ-f and hybrid VLES turbulence models
PublicationPresented paper summarizes the Authors findings referring to the numerical analyses of the jet impinging phenomena in the case of complex jets configurations in various applications e.g. in the heat exchangers. Multiple jets interference resulting in the cross-flow and the surface curvature are the factors which impose the need of advanced turbulence models utilization. The outcome of the research based on the ζ-f turbulence model...
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Fast Multi-Objective Aerodynamic Optimization Using Sequential Domain Patching and Multifidelity Models
PublicationExploration of design tradeoffs for aerodynamic surfaces requires solving of multi-objective optimization (MOO) problems. The major bottleneck here is the time-consuming evaluations of the computational fluid dynamics (CFD) model used to capture the nonlinear physics involved in designing aerodynamic surfaces. This, in conjunction with a large number of simulations necessary to yield a set of designs representing the best possible...
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Application of Diffusion Models in the Analysis of Financial Markets: Evidence on Exchange Traded Funds in Europe
PublicationExchange traded funds (ETFs) are financial innovations that may be considered as a part of the index financial instruments category, together with stock index derivatives. The aim of this paper is to explore the trajectories and formulates predictions regarding the spread of ETFs on the financial markets in six European countries. It demonstrates ETFs’ development trajectories with regard to stock index futures and options that...
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Ocena sił koniecznych do ciągnięcia węża gumowego z wodą
PublicationPrzeprowadzono analizę obciążeń działających na pracownika podczas wleczenia węża gumowego z wodą oraz wykonano doświadczalne badania wartości sił występujących podczas realizacji tego zadania. Dokonano krytycznej oceny wyników pod względem zgodności zmierzonych wartości sił z wymaganiami przepisów prawa obowiązujących w odniesieniu do BiHP.
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ENERGY STORAGE IN COMPRESSED AIR – SOLUTION SUPPORTING RENEWABLE ENERGY SOURCES
PublicationThis article presents a brief description of a power system, the current national power system daily load, the use of wind power as a renewable energy source and its share in the national load. It also discusses the methods for storing energy, their characteristics and possible solutions. The power storage and generation solution proposed in the article is based on the collaboration between a gas turbine and an air storage system....
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Use of Sensory Analysis Methods to Evaluate the Odor of Food and Outside Air
PublicationSensory analysis is applied in many areas of daily life. It is used to carry out the sensory evaluation of foodstuffs or other products and to evaluate the properties of odors present in the environment. The authors attempt to summarize the knowledge on the classification and application of sensory analysis methods to evaluate the odor nuisance of air, which allows the identification of sensory impressions and determination of...
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Klawiatura ekranowa dla osób posługujących się jedną kończyną górną
Publicationrtykuł prezentuje układ symboli na klawiaturze wirtualnej dedykowanej osobom niepełnosprawnym posługującym się jedną kończyną górną. Rozmieszczenie znaków zostało ustalone na podstawie przeprowadzonej analizy częstotliwości występowania poszczególnych liter w języku polskim. Uwzględniono również najczęściej występujące pary liter, a odpowiadające im klawisze ułożono blisko siebie. Zaproponowany kształt klawiatury jest wynikiem...
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Polskie Uczelnie Wyższe w XXI wieku muszą się zmienić!
PublicationStan szkolnictwa wyższego w Polsce i konieczności zmian. Uczelnie edukacyjne i uczelnie badawcze
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Design of Microwave Lossy Filter Based on Substrate Integrated Waveguide (SIW)
PublicationIn this letter, we propose a lossy three-pole Chebyshev filter centered at 5.15 GHz, based on the substrate integrated waveguide (SIW) with scattering characteristics shifted down by 5.68 dB. The filter is composed of three directly coupled SIW cavities with three lossy couplings between nonadjacent resonators. These additional couplings are realized using mixed coupled slot and microstrip lines connected with metal electrode leadless...
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Wpływ całkowitej zawartości sadzy na właściwości mieszanin SBR/dewulkanizat
PublicationPrzedstawiono wyniki badań wpływu napełniacza aktywnego w postaci sadzy na właściwości kompozycji kauczuku butadienowo-styrenowego i dewulkanizatu gumowego otrzymanego metodą ciągłą. Scharakteryzowano zależności pomiędzy sumaryczną ilością sadzy, stanowiącą sumę sadzy dodawanej i sadzy zawartej w dewulkanizacie gumowym, a charakterystyką przebiegu wulkanizacji, właściwościami fizycznymi oraz dynamicznymi właściwościami mechanicznymi...
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Elements of six sigma methodoloygy in polish smes. the pomeranian region context
PublicationIn this article, it has been suggested that the effectiveness of the design and implementation of the process approach in the SMEs sector affects the effectiveness and efficiency of the application of elements of the Six Sigma ™ concept. The selected results of the research have been presented to answer the question to what extent small and medium-sized manufacturing, service and production - service companies in Pomeranian region...
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Temperature-dependent interactions in the chitosan/cyclosporine A system at liquid–air interface
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Low-temperature air plasma modification of chitosan-coated PEEK biomaterials
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Detonations in hydrogen-methane-air mixtures in semi confined flat channels
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Influence of Air Velocity on the Total Thermal Insulation of Different Types of Clothing
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A study of possibility the air conditioning system in a car to become a bioaerosol generator
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Implementacja odbiornika RAKE w technologii SDR (Software Defined Radio)
PublicationRóżnorodność standardów systemów radiokomunikacyjnych, w tym telefonii komórkowej i bezprzewodowej, przy dużej ruchliwości ich abonentów, powoduje, że niezbędne jest skonstruowanie wielosystemowego terminala ruchomego, mającego techniczne możliwości współpracy z systemami radiokomunikacyjnymi działającymi w różnych standardach. W ten sposób zrodziła się idea radia definiowanego programowego SDR (Software Define Radio), bazująca...
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The Effect Fabrication Method of Cobalt Base Clad Layer On Air Oxidation
PublicationNapawane warstwy ze stopu kobaltu zostały wykonane za pomocą napawania plazmowego (PTA) oraz laserowego. Zostały one poddane utlenia niu w temperarurze 1100 stopni celsiusza prze 200 godzin. Przeprowadzono badania mikrostruktury i składu chemicznego warstwy tlenkowej oraz głębszych warstw napoiny. Nie stwierdzono wpływu metody wytwarzania na skutki procesu utleniania.
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Zagrożenia realizacji usług multimedialnych w systemach z sygnalizacją SIP
PublicationW pracy dokonano klasyfikacji powszechnych zagrożeń bezpieczeństwa w protokole SIP (RFC 3261). Opisano ataki wynikające ze słabości sieci IP jako głównego środowiska dla protokołu SIP oraz ataki wynikające ze sposobu działania protokołu SIP. Zidentyfikowano możliwość ich przeprowadzenia na produkcyjnych platformach SIP.
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Dedykowane sieciowe technologie SIP dla prezentacji pseudodynamicznych danych geoprzestrzennych
PublicationSieciowe technologie prezentacji danych przestrzennych przeżywają aktualnie rozkwit spowodowany między innymi spadającymi cenami sprzętu komputerowego. Wynikający z tego wzrost wydajności domowych i biurowych stacji roboczych pozwala na praktyczne zastosowanie czasochłonnych algorytmów wizualizacji i przetwarzania skomplikowanych danych rastrowych i wektorowych. Niniejszy artykuł omawia wybrane technologie sieciowej prezentacji...
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Poszukiwanie metody określania sił podłużnych w szynach toru bezstykowego
PublicationArtykuł przedstawia w zarysie przegląd wybranych prac badawczych nad znalezieniem metody określania sił podłużnych w szynach toru bezstykowego, przeprowadzonych na przestrzeni ostatnich kilkudziesięciu lat. Rozległość tych badań jest imponująca, jednak efekty wciąż nie są do końca zadowalające. Jak dotąd nie opracowano bowiem metody bezpośredniego pomiaru sił podłużnych, dostosowanej w pełni do warunków praktyki utrzymaniowej.