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Modelling of power electronic compensators for the analysis of power system operation
PublicationThe article presents selected methods of modelling power electronic compensators in order to analyze their operation in the power systems. Advantages and disadvantages of models have been shown with an indication of their usefulness for modelling specific phenomena.
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Combination of instrumental and qualitative descriptive analysis for evaluation of selected tonic waters quality features
PublicationThe combination of sensory and instrumental analysis was applied for quality assurance of selected tonic waters. The Quantitative Descriptive Analysis (QDA) in terms of fourteen sensory attributes (aroma, astringency, bite, burn, numbing, tongue heaviness, carbonation, mouth coating, sweet taste, sour taste, bitter taste, sweet aftertaste, sour aftertaste, bitter aftertaste) of selected tonic waters was performed by sensory experts....
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The Changing Nature of In‐Between Spaces in the Transformation Process of Cities
PublicationIn the in‐between spaces of cities, there are many problems of various nature and scale: functional, spatial, economic, environmental, visual, and social. There are also some hidden potentials that can be activated. The aim of the article is to explore the possibilities of solving existing problems and to show the possibilities of using the potentials of in‐between spaces with regard to the changing nature of a city. The article,...
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Fatigue strength determination of ship structural joints. Part I - Analytical methods for determining fatigue strength of ship tructures
PublicationSpectacular accidents at sea which have happened for a few last years show that hull structures of contemporary sea-going ships are not perfect and must be systematically improved. Fatigue strength is one of the groups of strength problems which affect design of contemporary ship's structures and greatly contribute in their improvement process. In this paper several approaches to estimation of fatigue life of hull structural...
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Artificial Neural Networks as an architectural design tool- generating new detail forms based on the Roman Corinthian order capital
PublicationThe following paper presents the results of the research in the field of the machine learning, investigating the scope of application of the artificial neural networks algorithms as a tool in architectural design. The computational experiment was held using the backward propagation of errors method of training the artificial neural network, which was trained based on the geometry of the details of the Roman Corinthian order capital....
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Combining MUSHRA Test and Fuzzy Logic in the Evaluation of Benefits of Using Hearing Prostheses
PublicationAssessing the effectiveness of hearing aid fittings based on the benefits they provide is crucial but intricate. While objective metrics of hearing aids like gain, frequency response, and distortion are measurable, they do not directly indicate user benefits. Hearing aid performance assessment encompasses various aspects, such as compensating for hearing loss and user satisfaction. The authors suggest enhancing the widely used...
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Mainstream shortcut N removal modeling current status and perspectives
PublicationThis work gives an overview of the state-of-the-art in modelling of short-cut processes for nitrogen removal in mainstream wastewater treatment and presents future perspectives for directing research efforts in line with the needs of practice. The modelling status for deammonification (i.e., anammox-based) and nitrite-shunt processes is presented with its challenges and limitations. The importance of mathematical models for considering...
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Experimental research of the stability of steel cylindricalshell subjected to circumferential compression
PublicationAt the Department of Metal Structures Gdańsk University of Technology, experiments have been performed on the stability of shell of steel cylindrical models. The experiments have been carried on a test bench built at the Department. The design based on other test benches which were created in the past by other scientists, where modernized by the courtesy of companies that offer modern solutions. The test bench enables to generate...
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Effective Short -term Forecasting of Wind Farms Power
PublicationForecasting a specific wind farm's generation capacity within a 24 hour perpective requires both a reliable forecast of wind, as well as supporting tools. This tool is a dedicated model of wind farm power. This model should include not only general rules of wind to mechanical energy conversion, but also the farm's specific features. This paper present analytical, statistical, and neuron models of wind farm power. The study is based...
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Human Factors and Functional Safety Analysis in Designing the Control Rooms of Industrial Hazardous Plants
PublicationIn this work some aspects of human factors and functional safety analysis in designing the control rooms of industrial hazardous plants are presented. The “defence in depth” (D-in-D) concept is outlined. Some designing issues of the alarm system (AS) with regard to human factors to be supported using the human reliability analysis (HRA) are discussed. The AS and decision support system (DSS), when properly designed, would contribute...
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An influence of the ship's block coefficient implementation on the evaluation of it's hull girder bending
PublicationAn influence of the three different ways of implementation ship's block coefficient δ (three geometrical models) on the stresses due to wave bending moment have been investigated. Two models have been applied and compared: beam one (description of the shape usingparameters) and FEM shell model (direct representation of the shape). The outcomes have been compared to Polish Register of Shipping (PRS) rules. The results show that...
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Multi-pulse VSC arrangements with coupled reactors
PublicationThis paper presents a novel approach to the multipulse VSC (Voltage Source Converter) arrangements based on several conventional inverter modules connected in parallel by using coupled reactors. This solution reduces the THD of the output voltage, despite the low switching frequency of transistors. The advantage of the proposed solution is also a relatively small rated power of the reactors. Proposed new arrangements for different...
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Shell model of multiple-row moment I-section end-plate joint
PublicationThe paper deals with a problem of application of shell elements in the models of multiple-row moment end-plate connections. The extended connection of I-section with a cross-section W760x265x220 made of steel S355 was analyzed. Comparison analysis of FEM, complex volume and shell models has been done. Three cases with different end-plate thickness: 14, 18 and 36 mm were analyzed and compared with the reference results. Comparison...
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Prosthetic Elements Made of the Ti-13Zr-13Nb Alloy by Selective Laser Melting
PublicationThe fabrication of the prosthetic foundations and bridges from the Ti-13Zr-13Nb alloy is described. The process was started from CAD/CAM design of 3D models of the foundations based on scanning of patient`s mouth. Next, 3D models were transformed into *.stl files for the manufacturing stage and then the manufacturing process by means of the selective laser melting with the SLM Realizer 100 equipment was made. The intrinsic structure...
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An Approach to Trust Case Development
PublicationIn the paper we present an approach to the architectural trust case development for DRIVE, the IT infrastructure supporting the processes of drugs distribution and application. The objectives of DRIVE included safer and cheaper drugs distribution and application. A trust case represents an argument supporting the trustworthiness of the system. It is decomposed into claims that postulate some trust related properties. Claims differ...
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Jakub Golik dr
PeopleJakub Golik currently works as a Research & Teaching Assistant at the Faculty of Management and Economics, Department of Entrepreneurship, Gdańsk University of Technology. Jakub does research in Utility-maximizing Models in Economy, Entrepreneurial Economics, Career Choice and Decision/Risk Theory. In his research he utilises mainly quantitative and experimental research methods including Conjoint Analysis and Structural Equation...
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Problems of modelling toxic compounds emitted by a marine internal combustion engine for the evaluation of its structure parameters
PublicationThe paper presents the possibility of using an analytical study of the engine exhaust ignition to evaluate the technical condition of the selected components. Software tools available for the analysis of experimental data commonly use multiple regression model that allows the study of the effects and iterations between model input quantities and one output variable. The use of multi-equation models gives a lot of freedom in the...
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On Alternative Approaches to Design of Corporate Feeds for Low-Sidelobe Microstrip Linear Arrays
PublicationTwo design approaches, illustrated by simulations and measurements, aiming at a systematic computer-aided design of printed circuit feeds for low-sidelobe microstrip antenna arrays are described. The novelty of these approaches resides in identification of the optimal feed architectures with subsequent simulation-based optimization of the feed and array aperture dimensions. In this work, we consider microstrip corporate feeds realizing...
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Modelling of high frequency dynamic responses of engineering structures
PublicationModelling of high frequency dynamic responses of engineering structures, especially those related to wave propagation, is a real numerical challenge. Nowadays most of numerical models, used for that purpose, are based on the application of various finite element techniques. However, finite element discrete models may also be considered as possessing certain periodic structures, which may manifest themselves in particular scenarios....
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Persistences: analysis of the image of Gdańsk and its cultural identity through survey processes and digital architectural representation
PublicationThe aim of the research was to analyse the historical legacy/heritage of the city of Gdańsk in order to characterise the narrative tools which can be used to promote the cultural identity of the urban landscape. The main focus was on the city's defence system - a cultural route that is spatially limited to a relatively small area, but temporally spanning almost a millennium. The fortifications demarcate a spatial boundary, limiting...
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Zarządzanie tożsamością w organizacjach na różnych poziomach zagregowania
PublicationNiniejszy artykuł stanowi naukową refleksję nad pojęciem tożsamości grupowej, odnoszonej do przedsiębiorstw oraz ich agregatów, określanych przez autorkę mianem „organizacji na wyższych poziomach zagregowania”. Głównym celem artykułu jest przegląd literatury z zakresu tożsamości przedsiębiorstwa, a na tej podstawie próba ustalenia czym jest taka tożsamość i co się na nią składa. Na wstępie autorka przedstawia definicje tożsamości...
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Modelling of network schedule including priority of selected technical resources
PublicationThe paper presents a method of network planning CPM – Critical Path Method. The author compares models of optimal solutions to design deadlines for individual works, taking various leading technical resources such as is labor and a tower crane into account.
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Development of proximity in cluster organizations
PublicationSustainable development in cluster organizations (COs) is most fully manifested in the synergy effect. In turn, the synergy effect is achieved thanks to the development of proximity among cluster entities. The purpose of the paper is to test two conceptual models reflecting relations between selected dimensions of proximity in cluster organizations. The author reports the findings of a quantitative study conducted in four COs....
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Ellipticity in couple-stress elasticity
PublicationWe discuss ellipticity property within the linear couple-stress elasticity. In this theory, there exists a deformation energy density introduced as a function of strains and gradient of macrorotations, where the latter are expressed through displacements. So the couple-stress theory could be treated as a particular class of strain gradient elasticity. Within the micropolar elasticity, the model is called Cosserat pseudocontinuum...
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Viewpoint independent shape-based object classification for video surveillance
PublicationA method for shape based object classification is presented.Unlike object dimension based methods it does not require any system calibration techniques. A number of 3D object models are utilized as a source of training dataset for a specified camera orientation. Usage of the 3D models allows to perform the dataset creation process semiautomatically. The background subtraction method is used for the purpose of detecting moving objects...
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Solvent-Free Synthesis of Phosphonic Graphene Derivative and Its Application in Mercury Ions Adsorption
PublicationFunctionalized graphene was efficiently prepared through ball-milling of graphite in the presence of dry ice. In this way, oxygen functional groups were introduced into material. The material was further chemically functionalized to produce graphene derivative with phosphonic groups. The obtained materials were characterized by spectroscopic and microscopic methods, along with thermogravimetric analysis. The newly developed material...
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Fractional Calculus Evaluation of Hyaluronic Acid Crosslinking in a Nanoscopic Part of Articular Cartilage Model System
PublicationThis work presents a study of the mechanism of physical crosslinking of hyaluronic acid in the presence of common phospholipids in synovial joint organ systems. Molecular dynamic simulations have been executed to understand the formation of hyaluronan networks at various phospholipid concentrations. The results of the simulations suggest that the mechanisms exhibit subdiffusion characteristics. Transportation quantities derive...
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Designing Particle Kalman Filter for Dynamic Positioning
PublicationThe article presents a comparative analysis of two variants of the Particle Kalman Filter designed by using two different ship motion models. The first filter bases only on the kinematic model of the ship and can be used in many types of vehicles, regardless of the vehicle dynamics model. The input value to the filter is the noisy position of the ship. The second filter makes use of the kinematic and dynamic models of the moving...
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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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Identifying the Effects of Selected Road and Roadside Parameters on Road Safety Using Geodetic Techniques
PublicationThe paper will present techniques that can be used to obtain data on road alignment and profile including the roadside. In-the-field and simulation studies have helped to develop mathematical models that integrate vehicle position data. The experiments were conducted in a virtual environment using the software ArcGIS that reflects the actual roadside conditions. The site tests were made using a purpose-built device which integrates...
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Model neuronowy jako alternatywa dla numerycznego modelu okołodźwiękowego przepływu pary przez palisadę turbinową.
PublicationWystępowanie skośnej fali uderzeniowej w przepływie pary przez palisadę turbinową stanowi zagrożenie dla bezpiecznej pracy turbiny oraz dla jej elementów konstrukcyjnych. Detekcja oraz lokalizacja fali uderzeniowej, a także rozpoznanie przyczyny jej powstawania, nie są możliwe do osiągnięcia na drodze pomiarowej. Analizę zjawisk zachodzących wewnątrz kanału przepływowego umożliwiają natomiast modele numeryczne oraz neuronowe. Zaletą...
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Prognozowanie ostrzegawcze w małej firmie
PublicationW artykule pokazano możliwości zastosowania prostych metod prognostycznych do ostrzegania w małej firmie przed niekorzystnymi zjawiskami. Przedmiotem badań jest sprzedaż, a ze względu na występowanie w szeregu czasowym sezonowości, w celu wyznaczenia sygnałów ostrzegawczych dokonano porównań trendów prognozowanych i rzeczywistych w okresach jednoimiennych za pomocą pierwszych różnic. Do prognozowania sprzedaży wykorzystano proste...
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System of innovation: a sectoral approach
Publicationthe article presents a systems approach to innovation as an alternative method of assessing the sector innovativeness. in the article the building blocks of each sectoral system of innovations (ssi) such as a knowledge base, institutions and actors are discussed. moreover, the five models of ssi are presented.
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Some aspects of the constitutive modelling of natural fine grained soils
PublicationThe monograph deals with selected problems of the constitutive modelling of natural fine grained soils commonly known as clays. The main idea is not to propose a unified model which is capable of describing all known features of mechanical behaviour of fine grained soils. Instead, separate models are proposed describing the mechanical behaviour of heavily overconsolidated, lightly overconsolidated and normally consolidated clays....
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Study of various machine learning approaches for Sentinel-2 derived bathymetry
PublicationIn recent years precise and up-to-date information regarding seabed depth has become more and more important for companies and institutions that operate on coastlines. While direct, in-situ measurements are performed regularly, they are expensive, time-consuming and impractical to be performed in short time intervals. At the same time, an ever-increasing amount of satellite imaging data becomes available. With these images, it...
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Clinical anatomy of the spatial structure of the right ventricular outflow trac
PublicationBackground. The right ventricular outflow tract (RVOT) is located above the supraventricular crest and reaches the level of the pulmonary valve. Detailed knowledge of the RVOT spatial structure and its morphology is extremely important for cardiac invasive therapeutic procedures. Objectives. To examine the spatial structure of the RVOT using virtual models of the right ventricle (RV) interior obtained post mortem. Material and...
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Polynomial Chaos Expansion in Bio-and Structural Mechanics
PublicationThis monograph presents a probabilistic approach to modelling the mechanics of materials and structures where the modelled performance is influenced by uncertainty in the input parameters. The work is interdisciplinary and the methods described are applied to medical and civil engineering problems. The motivation for this work was the necessity of mechanics-based approaches in the modelling and simulation of implants used in the...
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Mathematical modelling and computer simulation of activated sludge systems.Second edition
PublicationMathematical Modelling and Computer Simulation of Activated Sludge Systems – Second Edition, provides, from the process engineering perspective, a comprehensive and up-to-date overview regarding various aspects of the mechanistic (“white box”) modelling and simulation of advanced activated sludge systems performing biological nutrient removal. In the new edition of the book, a special focus is given to nitrogen removal and an overview...
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Reduced-cost electromagnetic-driven optimisation of antenna structures by means of trust-region gradient-search with sparse Jacobian updates
PublicationNumerical optimisation plays more and more important role in the antenna design. Because of lack of design-ready theoretical models, electromagnetic (EM)-simulation-driven adjustment of geometry parameters is a necessary step of the design process. At the same time, traditional parameter sweeping cannot handle complex topologies and large number of design variables. On the other hand, high computational cost of the conventional...
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An improvement of body surface area formulas using the 3D scanning technique
PublicationObjectives: Body surface area (BSA) is one of the major parameters used in several medical fields. However, there are concerns raised about its usefulness, mostly due to the ambiguity of its estimation. Material and Methods: Authors have conducted a voluntary study to investigate BSA distribution and estimation in a group of 179 adult people of various sex, age, and physique. Here, there is provided an extended analysis of the...
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Polynomial Chaos Expansion in Bio- and Structural Mechanics
PublicationThis thesis presents a probabilistic approach to modelling the mechanics of materials and structures where the modelled performance is influenced by uncertainty in the input parameters. The work is interdisciplinary and the methods described are applied to medical and civil engineering problems. The motivation for this work was the necessity of mechanics-based approaches in the modelling and simulation of implants used in the repair...
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Development of the System Assurance Reference Model for Generating Modular Assurance Cases
PublicationAssurance cases are structured arguments used to demonstrate specific system properties such as safety or security. They are used in many industrial sectors including automotive, aviation and medical devices. Larger assurance cases are usually divided into modules to manage the complexity and distribute the work. Each of the modules is developed to address specific goals allocated to the specific objects i.e. components of the...
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Prediction of ringing frequencies in DC-DC boost converter
PublicationIn the paper ringing phenomena in a DC-DC boost converter is presented. The ringing frequency is calculated using an analytical formula. The necessary wide band models of MOSFET transistor, passive and parasitics are described. The calculation results are verified in simulation and laboratory tests.
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Category-Based Workload Modeling for Hardware Load Prediction in Heterogeneous IaaS Cloud
PublicationThe paper presents a method of hardware load prediction using workload models based on application categories and high-level characteristics. Application of the method to the problem of optimization of virtual machine scheduling in a heterogeneous Infrastructure as a Service (IaaS) computing cloud is described.
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FORECASTING EXCHANGE RATES IN THE PROCESS OF THE ASSESSMENT OF CONSUMER RISK BANKRUPTCY IN CENTRAL EUROPE
PublicationThis paper focuses on the issue of forecasting the fluctuation of exchange rates as part of the early warning system against the risk of consumer bankruptcy. The author identified the main macroeconomic factors affecting the level of bankruptcies for households in Poland. The fluctuation of exchange rates, which directly affects the deterioration of the economic situation of borrowers who have opened credit accounts in a foreign...
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Market Regeneration in Line with Sustainable Urban Development
PublicationThis article presents the study of the optimal design solutions for regeneration of marketplaces. It examines the design variants for the revitalisation of the marketplace, in particular, investment in their modernisation in order to find the most optimal model for transforming these public spaces to have a significant impact on the city’s development. The research is a comparative analysis of the implementation of regeneration...
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Resistant to correlated noise and outliers discrete identification of continuous non-linear non-stationary dynamic objects
PublicationIn this article, specific methods of parameter estimation were used to identify the coefficients of continuous models represented by linear and nonlinear differential equations. The necessary discrete-time approximation of the base model is achieved by appropriately tuned FIR linear integral filters. The resulting discrete descriptions, which retain the original continuous parameterization, can then be identified using the classical...
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Resistant to correlated noise and outliers discrete identification of continuous non-linear non-stationary dynamic objects
PublicationIn this study, dedicated methods of parameter estimation were used to identify the coefficients of continuous models represented by linear and nonlinear differential equations. The necessary discrete-time approximation of the base model is achieved by appropriately tuned FIR linear integral filters. The resulting discrete descriptions, which retain the original continuous parameterization, can then be identified using the classical...
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A numerical and experimental analysis of multi-hole orifice in turbulent flow
PublicationIn this research study, the comprehensive metrological analysis is investigated for a 4-hole orifice with module m = 0.25 installed in the pipeline with an internal diameter of 50 mm. A detailed numerical simulation was performed for the turbulence models: k-ε-realizable and k-ω-BSL. The novelties of the research include model validation by comparing the results of numerical studies with the experiment conducted in the area of...
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ADAPTIVE PREDICTIONS OF THE EURO/ZŁOTY CURRENCY EXCHANGE RATE USING STATE SPACE WAVELET NETWORKS AND FORECAST COMBINATIONS
PublicationThe paper considers the forecasting of the euro/Polish złoty (EUR/PLN) spot exchange rate by applying state space wavelet network and econometric forecast combination models. Both prediction methods are applied to produce one-trading-day- ahead forecasts of the EUR/PLN exchange rate. The paper presents the general state space wavelet network and forecast combination models as well as their underlying principles. The state space...