2020 - Repozytorium publikacji - Politechnika Gdańska

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A framework for accelerated optimization of antennas using design database and initial parameter set estimation
- Sławomir Kozieł
- Adrian Bekasiewicz
2020 Pełny tekst ENGINEERING COMPUTATIONS
The purpose of this paper is to exploit a database of pre-existing designs to accelerate parametric optimization of antenna structures is investigated. Design/methodology/approach The usefulness of pre-existing designs for rapid design of antennas is investigated. The proposed approach exploits the database existing antenna base designs to determine a good starting point for structure optimization and its response sensitivities. The considered method is suitable for handling computationally expensive models, which are evaluated using full-wave electromagnetic (EM) simulations. Numerical case studies are provided demonstrating the feasibility of the framework for the design of real-world structures. Findings The use of pre-existing designs enables rapid identification of a good starting point for antenna optimization and speeds-up estimation of the structure response sensitivities. The base designs can be arranged into subsets (simplexes) in the objective space and used to represent the target vector, i.e. the starting point for structure design. The base closest base point w.r.t. the initial design can be used to initialize Jacobian for local optimization. Moreover, local optimization costs can be reduced through the use of Broyden formula for Jacobian updates in consecutive iterations. Research limitations/implications The study investigates the possibility of reusing pre-existing designs for the acceleration of antenna optimization. The proposed technique enables the identification of a good starting point and reduces the number of expensive EM simulations required to obtain the final design. Originality/value The proposed design framework proved to be useful for the identification of good initial design and rapid optimization of modern antennas. Identification of the starting point for the design of such structures is extremely challenging when using conventional methods involving parametric studies or repetitive local optimizations. The presented methodology proved to be a useful design and geometry scaling tool when previously obtained designs are available for the same antenna structure.
A framework for Air Quality Management Zones - Useful GIS-based tool for urban planning: Case studies in Antwerp and Gdańsk
- Joanna Badach
- Dimitri Voordeckers
- Lucyna Nyka
- Maarten Van Acker
2020 Pełny tekst BUILDING AND ENVIRONMENT
There is a growing recognition of the importance of proper urban design in the improvement of air flow and pollution dispersion and in reducing human exposure to air pollution. However, a limited number of studies have been published so far focusing on the development of standard procedures which could be applied by urban planners to effectively evaluate urban conditions with respect to air quality. To fill this gap, a new approach for the determination of urban Air Quality Management Zones (AQMZs) was proposed and presented based on two case studies: Antwerp, Belgium and Gdańsk, Poland. The main objectives of the study were to 1) formulate a theoretical framework for the management of urban ventilation potential and human exposure to air pollution and to 2) develop methods for its implementation by means of a geographic information system (GIS). As a result of the analysis, the typologies that may be associated with decreased ventilation potential and the areas that require close monitoring due to potential human exposure to air pollution were identified for both cities. It is advocated that delimiting these typologies – combined with investigating local climate, wind and topography conditions and air pollution characteristics – could constitute a preliminary step in the urban planning process aimed at air quality improvement. These methods can be further applied to other urban areas in order to indicate where detailed studies are required and to facilitate the development of planning guidelines. Moreover, the directions for further research and urban planning strategies were discussed.
A Framework for Enhancing Supplier Selection Process by Using SOEKS and Decisional DNA
- Muhammad Ahmed
- Cesar Sanin
- Edward Szczerbicki
2020 Pełny tekst Communications in Computer and Information Science
Abstract. Supplier selection process is one of the significant stages in supply chain management for industrial manufactured products. It plays an integral role in the success of any manufacturing organization and is an important part starting right from selecting raw material to dispatch of finished products. This paper contributes to enhance the supplier selection process by proposing a multi-criteria decision making framework for industrial manufactured products. The proposed framework is based on smart knowledge management technique called Set of experience knowledge structure (SOEKS) and Decisional DNA, which makes the proposed approach dynamic in nature as it updates itself every time a decision is taken.
A global multinational survey of cefotaxime-resistant coliforms in urban wastewater treatment plants
- Roberto Marano
- Telma Fernandes
- Celia M. Manaia
- Olga Nunes
- Donald Morrison
- Thomas U. Berendonk
- Norbert Kreuzinger
- Tanel Telson
- Gianluca Corno
- Despo Fatta-Kassinos
- Christophe Merlin
- Edward Topp
- Edouard Jurkevitch
- Leonie Henn
- Andrew Scott
- Stefanie Hess
- Katarzyna Slipko
- Mailis Laht
- Veljo Kisand
- Andrea Di Cesare
- Popi Karaolia
- Stella G. Michael
- Alice L Petre
- Roberto Rosal
- Amy Pruden
- Virgina Riquemle
- Ana Aguera
- Belen Esterban
- Aneta Łuczkiewicz
- Agnieszka Kalinowska
- Anne Leonard
- William H. Gaze
- Anthony A. Adegooke
- Thor A. Stenstrom
- Alfieri Pollice
- Carlo Salerno
- Carsten U. Schwermer
- Paweł Krzemiński
- Helene Guilloteau
- Erica Donner
- Barbara Drigo
- Giovanni Libralato
- Marco Guida
- Helmut Burgmann
- Karin Beck
- Hemda Garelick
- Marta Tacao
- Isabel Henriques
- Isabel Martinez-Alcala
- Jose M. Guillien-Navarro
- Magdalena Popowska
- Marta Piotrowska
- Markos Quintela-Baluja
- Joshua T. Bunce
- Maria I. Polo-Lopez
- Samira Nahim-Granados
- Marie-Noelle Pons
- Milena Milakovic
- Nikolina Udikovic-Kolic
- Jerome Ory
- Traore Ousmane
- Pilar Caballero
- Antoni Oliver
- Sara Rodriguez-Mozaz
- Jose L. Balcazar
- Thomas Jager
- Thomas Schwartz
- Ying Yang
- Shichun Zou
- Yunho Lee
- Younggun Yoon
- Bastian Herzog
- Heidrun Mayrhofer
- Om Prakash
- Yogesh Nimonkar
- Ester Heath
- Anna Baraniak
- Joana Abreu-Silva
- Manika Choudhury
- Leonardo P. Munoz
- Stela Krizanovic
- Gianluca Brunetti
- Ayella Maile-Moskowitz
- Connor Brown
- Eddie Cytryn
2020 Pełny tekst ENVIRONMENT INTERNATIONAL
The World Health Organization Global Action Plan recommends integrated surveillance programs as crucial strategies for monitoring antibiotic resistance. Although several national surveillance programs are in place for clinical and veterinary settings, no such schemes exist for monitoring antibiotic-resistant bacteria in the environment. In this transnational study, we developed, validated, and tested a low-cost surveillance and easy to implement approach to evaluate antibiotic resistance in wastewater treatment plants (WWTPs) by targeting cefotaxime-resistant (CTX-R) coliforms as indicators. The rationale for this approach was: i) coliform quantification methods are internationally accepted as indicators of fecal contamination in recreational waters and are therefore routinely applied in analytical labs; ii) CTX-R coliforms are clinically relevant, associated with extended-spectrum β-lactamases (ESBLs), and are rare in pristine environments. We analyzed 57 WWTPs in 22 countries across Europe, Asia, Africa, Australia, and North America. CTX-R coliforms were ubiquitous in raw sewage and their relative abundance varied significantly (<0.1% to 38.3%), being positively correlated (p < 0.001) with regional atmospheric temperatures. Although most WWTPs removed large proportions of CTX-R coliforms, loads over 103 colony-forming units per mL were occasionally observed in final effluents. We demonstrate that CTX-R coliform monitoring is a feasible and affordable approach to assess wastewater antibiotic resistance status.
A Highly Sensitive Planar Microwave Sensor for Detecting Direction and Angle of Rotation
- Abhishek Jha
- Adam Lamęcki
- Michał Mrozowski
- Bozzi Maurizio
2020 Pełny tekst IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
This article presents a technique based on a modified complementary split-ring resonator (CSRR) to detect angular displacement and direction of rotation with high resolution and sensitivity over a wide dynamic range. The proposed microwave planar sensor takes advantage of the asymmetry of the sensor geometry and measures the angle of rotation in terms of the change in the relative phase of the reflection coefficients. The sensor consists of a movable modified CSRR (the rotor) and a microstrip line with a circular defect in the ground plane (the stator). By selecting the substrate material and the rotor thickness, the sensor can be designed to work at different operating frequencies. A theoretical model of the sensor is proposed and is followed by a detailed numerical analysis involving equivalent circuit simulations, full-wave computations, and measurement results. Using positioning error estimation and air-gap analysis, a technique based on phase-change measurements is found to be better than those based on magnitude measurements alone. The maximum sensitivity for measuring the angular rotation is found to be a 4.3◦ change in the relative phase of the reflection coefficient per 1◦ of rotation. The sensor has an angular measurement range from −90◦ to +90◦. The sensor—a stator fabricated on a 0.5-mm-thick Rogers RT5880 substrate and three rotors fabricated on a 1.5-mm-thick Rogers RT5880, a 1-mmthick FR4, and a 0.5-mm-thick Rogers RT5880—can effectively detect the direction of rotation, measure the angle of rotation and angular velocity with reasonable accuracy.
A literature survey of the influence of preform reheating and stretch blow molding with hot mold process parameters on the properties of PET containers. Part I.
- Waldemar Karaszewski
- Paweł Wawrzyniak
2020 Pełny tekst Polimery
The hot fill process is an inexpensive conventional filling technology for high-acidity products (pH < 4.5). It allows certain drinks (sensitive beverages such as fruit and vegetable juices, nectars, soft drinks, vitaminized water) to be stored at ambient temperature without the need for chemical preservatives. The primary feature of the bottles used in the hot fill process is their temperature stability, i.e. the ability to retain the shape of the bottle at the filling temperature. From a mechanical point of view, the thermal stability of PET bottles manufactured by the ISBM process is determined by the mechanical and thermal response of the blown preforms. From a microscopic point of view, the strongest influences on the mechanical and thermal properties of PET bottles are the orientation and crystallisation processes. From a technological point of view, the properties of PET bottles after manufacture by the stretch blow moulding process is mainly determined by the initial structure of the PET preform, the geometry and temperature distribution of the preform, the geometry of the blow mould and technological parameters of the blowing moulding process. The paper presents a wide analysis of the literature on the modified blow molding process with simultaneous stretching of PET material for storing hot filled drinks.
A literature survey of the influence of preform reheating and stretch blow moulding with hot mould process parameters on the properties of PET containers – part 2.
- Waldemar Karaszewski
- Paweł Wawrzyniak
2020 Pełny tekst Polimery
The hot fill process is an inexpensive conventional filling technology for high-acidity products (pH < 4.5). It allows certain drinks (sensitive beverages such as fruit and vegetable juices, nectars, soft drinks, vitaminised water) to be stored at ambient temperature without the need for chemical preservatives. The primary feature of the bottles used in the hot fill process is their temperature stability, i.e. the ability to retain the shape of the bottle at the filling temperature. From a mechanical point of view, the thermal stability of PET bottles manufactured by the ISBM process is determined by the mechanical and thermal response of the blown preforms. From a microscopic point of view, the strongest influences on the mechanical and thermal properties of PET bottles are the orientation and crystallisation processes. From a technological point of view, the properties of PET bottles after manufacture by the stretch blow moulding process is mainly determined by the initial structure of the PET preform, the geometry and temperature distribution of the preform, the geometry of the blow mould and technological parameters of the blowing moulding process. The paper presents a wide analysis of the literature on the modified blow molding process with simultaneous stretching of PET material for storing hot filled drinks.
A Loophole of All ‘Loophole-Free’ Bell-Type Theorems
- Marek Czachor
2020 Pełny tekst Foundations of Science
Bell’s theorem cannot be proved if complementary measurements have to be represented by random variables which cannot be added or multiplied. One such case occurs if their domains are not identical. The case more directly related to the Einstein–Rosen–Podolsky argument occurs if there exists an ‘element of reality’ but nevertheless addition of complementary results is impossible because they are represented by elements from different arithmetics. A naive mixing of arithmetics leads to contradictions at a much more elementary level than the Clauser–Horne–Shimony–Holt inequality.
A Measurable Selector in Kadison’s Carpenter’s Theorem
- Marcin Bownik
- Marcin Szyszkowski
2020 Pełny tekst CANADIAN JOURNAL OF MATHEMATICS-JOURNAL CANADIEN DE MATHEMATIQUES
We show the existence of a measurable selector in Carpenter’s Theorem due to Kadison. This solves a problem posed by Jasper and the first author in an earlier work. As an application we obtain a characterization of all possible spectral functions of shift-invariant subspaces of L 2 (R d ) and Carpenter’s Theorem for type I ∞ von Neumann algebras.
A measurement method for capacitive sensors based on a versatile direct sensor-to-microcontroller interface circuit
- Zbigniew Czaja
2020 Pełny tekst MEASUREMENT
In the paper, there is presented a new time-domain measurement method for determining the capacitance values of capacitive sensors, dedicated, among others, to capacitive relative humidity sensors. The method is based on a versatile direct sensor-to-microcontroller interface for microcontrollers with internal analog comparators (ACs) and with precision voltage reference sources, e.g. digital-to-analog converters (DACs). The reference source can be replaced by a resistive divider attached to the negative input of the AC. The interface circuit consists only of a reference resistor Rr, a given capacitive sensor working as a voltage divider, and a microcontroller (its peripherals: AC, timer, DAC, I/O pins). A prototype of the proposed complete solution of a compact capacitive smart sensor based on an 8-bit ATXmega32A4 microcontroller has been developed and tested. The maximum possible relative inaccuracy of an indirectly measurable capacitance was analysed, and experimental research was also performed. The results confirmed that the relative errors of value determination for a capacitive sensor are less than ±0.06%, which corresponds to a capacitance measurement accuracy of less than 0.1 pF for a range of measured capacity values from 100 pF to 225 pF, which in turn corresponds to at least a 0.5% relative humidity resolution for commercial capacitive RH sensors (e.g. TE Connectivity HS1101LF and Philips H1).
A modelling approach to the transport support for the harvesting and transportation complex under uncertain conditions
- Ievgen Medvediev
- Peter Eliseyev
- Iryna Lebid
- Olha Sakno
2020 Pełny tekst IOP Conference Series: Materials Science and Engineering
The article proposes a modelling approach based on structural and parametric identification of the transport support of the harvesting and transportation complex. The efficiency and effectiveness of the proposed methods of structural and parametric identification for the development of a system for harvesting and transportation complex operation has been proved. A mathematical model based on fuzzy logic has been developed. It reflects the interaction and interference of the weather-climatic, technical and technological parameters of transport support and its elements. A simulation method of transport support for harvesting and transport complex has been developed. The basis of the method is an algorithm for constructing a flow chart for the transport system operation consisting of structural and parametric identification levels and a mathematical model for the winter wheat harvesting transportation. A special feature of the method is the consideration of the weather-climatic, technical and technological parameters of the harvesting-transportation complex.
A new concept of PWM duty cycle computation using the Barycentric Coordinates in a Three-Dimensional voltage vectors arrangement
- Paweł Szczepankowski
- Nikolai Poliakov
- Denis Vertegel
- Krzysztof Szwarc
- Ryszard Strzelecki
2020 Pełny tekst IEEE Access
The paper presents a novel approach to the Pulse Width Modulation (PWM) duty cycle computing for complex or irregular voltage vector arrangements in the two (2D) and three–dimensional (3D) Cartesian coordinate systems. The given vectors arrangement can be built using at least three vectors or collections with variable number of involved vectors (i.e. virtual vectors). Graphically, these vectors form a convex figure, in particular, a triangle or a tetrahedron. The reference voltage vector position inside that figure can be expressed by the barycentric coordinates, which are calculated using the second (2D case) or the third–degree determinant (3D case) – without trigonometry and angles. Thus, the speed of the PWM duty cycle computation rises significantly. The use of the triangle area or the tetrahedron volume, instead of the standard vector projection also permits for a well–defined and universal approach to identifying the reference vector position, especially for converters with complex and/or deformed space–vector diagrams (i.e. floating DC–link, multisource DC–link). The proposed computation scheme is based on simple instructions without trigonometry thereby, the DSP processor, or digital solution for field–programmable gate array, can fast–perform this operation using atomic operations. The aim of the presented considerations is not a novel PWM modulation, but a computable idea of a general calculation scheme for cases in which the distribution of vectors is non-trivial. A detailed algebraic and geometric analysis, as well as mathematical proofs on the total consistency of the results with the standard projection method, are also included. Subsequently, the Three–Dimensional Space Vector Modulation (3D–SVM), is considered as a special background to present a novel approach.
A new construction of shell-and-tube heat exchanger with impinging jets and minichannels technologies for heat recovery from gases – experimental analysis
- Jan Wajs
- Roksana Bochniak
- Aleksandra Gołąbek
- Tomasz Kura
2020
A dynamic development of technologies allowing waste heat utilization is observed in a correspondence with a pro-ecological approach of the zero waste idea. Such approach becomes the most demanding in the area of low-temperature was heat sources, especially gaseous media. Till now, they were usually not utilized due to unfavorable thermal conditions and high costs. Therefore, the zero waste approach directs research on techniques for heat exchange intensification and increasing heat transfer coefficients. In many cases, it is connected with the compact heat exchangers oriented on the low-temperature heat recovery from gaseous sources. Passive intensification methods, characterized by low energy consumption are primarily desirable. The shell-and-tube heat exchanger is a type of commonly applied unit in various industry branches, that is why it is considered as the most suitable for improvements. The passive techniques, implemented in it, are very often connected with various types of inserts in the bundle of tubes, which intensify the heat exchange process on the gas side and are a relatively simple modification even of existing heat exchangers. The inserts are of various shapes, optimized toward particular applications and sometimes combined with other techniques. Following the pro-ecological approach, the authors proposed an innovative shell-and-tube heat exchanger a new type of inserts, designed to transfer high heat fluxes. Proposed construction based on the previous experiences with the impinging jets technology, which confirmed its validity in the cylindrical heat exchangers. Novelty of the tube inserts relies on generation of jets impinging on the heat exchange surface. To enhance a compactness of the heat exchanger, the minichannels technology was also implemented - the inlet diameter of single perforated tube is 2 mm. In this paper the construction and principles of operation of described shell-and-tube heat exchanger were discussed. The experimental stand and investigations of heat exchanger thermal performance in a single-phase convection in the gas-liquid system were presented. Analysis of obtained data provides the basis for further development of a correlation describing the Nusselt number for shell-and-tube heat exchangers with impinging jet technique.
A new hyperbolic-polynomial higher-order elasticity theory for mechanics of thick FGM beams with imperfection in the material composition
- Mohammad Malikan
- Victor Eremeev
2020 Pełny tekst COMPOSITE STRUCTURES
A drawback to the material composition of thick functionally graded materials (FGM) beams is checked out in this research in conjunction with a novel hyperbolic‐polynomial higher‐order elasticity beam theory (HPET). The proposed beam model consists of a novel shape function for the distribution of shear stress deformation in the transverse coordinate. The beam theory also incorporates the stretching effect to present an indirect effect of thickness variations. As a result of compounding the proposed beam model in linear Lagrangian strains and variational of energy, the system of equations is obtained. The Galerkin method is here expanded for several edge conditions to obtain elastic critical buckling values. First, the importance of the higher‐order beam theory, as well as stretching effect, is assessed in assorted tabulated comparisons. Next, with validations based on the existing and open literature, the proposed shape function is evaluated to consider the desired accuracy. Some comparative graphs by means of well‐known shape functions are plotted. These comparisons reveal a very good compliance. In the final section of the paper, based on an inappropriate mixture of the SUS304 and Si3C4 as the first type of FGM beam (Beam‐I) and, Al and Al2O3 as the second type (Beam‐II), the results are pictured while the beam is kept in four states, clamped–clamped (C–C), pinned–pinned (S–S), clamped-pinned (C–S) and in particular cantilever (C–F). We found that the defect impresses markedly an FGM beam with boundary conditions with lower degrees of freedom.
A new look at the statistical identification of nonstationary systems
- Maciej Niedźwiecki
- Marcin Ciołek
- Artur Gańcza
2020 Pełny tekst AUTOMATICA
The paper presents a new, two-stage approach to identification of linear time-varying stochastic systems, based on the concepts of preestimation and postfiltering. The proposed preestimated parameter trajectories are unbiased but have large variability. Hence, to obtain reliable estimates of system parameters, the preestimated trajectories must be further filtered (postfiltered). It is shown how one can design and optimize such postfilters using the basis function framework. The proposed solution to adaptive tuning of postfilter settings is based on parallel estimation and cross-validatory analysis. When compared with the classical solutions to the problem of parameter tracking, the new approach offers, without compromising good tracking performance, significant computational savings, higher numerical robustness and greater flexibility.
A New Method of Noncausal Identification of Time-varying Systems
- Maciej Niedźwiecki
- Marcin Ciołek
- Artur Gańcza
- Piotr Kaczmarek
2020 Pełny tekst
The paper shows that the problem of noncausal identification of a time-varying FIR (finite impulse response) sys- tem can be reformulated, and solved, as a problem of smoothing of the preestimated parameter trajectories. Characteristics of the smoothing filter should be chosen so as to provide the best trade- off between the bias and variance of the resulting estimates. It is shown that optimization of the smoothing operation can be performed adaptively using the parallel estimation technique.
A nontargeted approach to determine the authenticity of Ginkgo biloba L. plant materials and dried leaf extracts by liquid chromatography-high-resolution mass spectrometry (LC-HRMS) and chemometrics
- Meryl Cruz
- Benjamin J. Place
- Laura J. Wood
- Aaron Urbas
- Andrzej Wasik
- Werickson Fortunato de Carvalho Rocha
2020 Pełny tekst ANALYTICAL AND BIOANALYTICAL CHEMISTRY
The lack of stringent regulations regarding raw materials for herbal supplements used for medicinal purposes has been a constant challenge in the industry. Ginkgo biloba L. leaf extracts attract consumers because of the supposed positive effect on mental performance and memory. Supplements are produced using dried leaf materials and standardized leaf extracts such as EGb 761. Adulteration of Ginkgo biloba L. plants and extracts are becoming more and more common practice due to economically driven motivation from increasing demand in the market and the high cost of raw materials and production. Reinforcement in quality control (QC) to avoid adulterations is necessary to ensure the efficacy of the supplements. In this study, liquid chromatographyhigh-resolution mass spectrometry (LC-HRMS) was used with principal component analysis (PCA) as an unsupervised exploratory method to analyze, identify, and evaluate the adulterated Ginkgo biloba L. plant materials and dried leaf extracts using the PCA scores and loadings obtained and compound identification.
A note on polynomial algorithm for cost coloring of bipartite graphs with Δ ≤ 4
- Krzysztof Giaro
- Marek Kubale
2020 Pełny tekst Discussiones Mathematicae Graph Theory
In the note we consider vertex coloring of a graph in which each color has an associated cost which is incurred each time the color is assigned to a vertex. The cost of coloring is the sum of costs incurred at each vertex. We show that the minimum cost coloring problem for n-vertex bipartite graph of degree ∆≤4 can be solved in O(n^2) time. This extends Jansen’s result [K.Jansen,The optimum cost chromatic partition problem, in: Proc. CIAC’97,Lecture Notes in Comput. Sci. 1203 (1997) 25–36] for paths and cycles to subgraphs of biquartic graphs.
A novel concept of negative CO2 emission power plant for utilization of sewage sludge
- Paweł Ziółkowski
- Janusz Badur
- Halina Pawlak-kruczek
- Lukasz Niedzwiecki
- Mateusz Kowal
- Krystian Krochmalny
2020
Carbon Capture and Storage (CSS) technology is considered an important “bridge technology”, allowing effective abatement of CO2 emissions for power units using fossil fuels. However, if biomass is used in a power plant, equipped with CCS system, negative CO2 emissions can be achieved. In practice, wide development of such technologies would enable not only reduction of CO2 emissions, but also reversal of the harm done so far. In the long term, wide application of technologies with carbon-negative emissions could allow coming back to pre-industrial concentrations of CO2 in the atmosphere. Sewage sludge is a residue of the wastewater processing, that is a biologically active and consists of water, organic matter, including dead and alive pathogens, as well as organic and inorganic contaminants such as polycyclic aromatic hydrocarbons (PAHs) and heavy metals. Due to the nature of sewage sludge and its possible influence on human health and wellbeing, it is a subject of various regulations. Currently, sewage sludge is considered a biomass, according to the new Polish act on renewable energy sources from 20th of February 2015 and its novel version from 19th of July 2019. This study presents a novel approach, that aims at assessing feasibility of the concept of a negative CO2 emission power plant, based on steam gasification of sewage sludge, subsequent combustion of the producer gas in a gas turbine with spray-ejector condenser. This novel solution offers an efficient way to convert the chemical energy in the sewage sludge and, in the same time, compress and capture CO2. Possibility to utilize sewage sludge is an additional advantage of the proposed solution. For example: composition and calorific value of the dry producer gas, determined experimentally, are as follows: YCO=0.133; YCO2=0.593; YCH4=0.117; YCnHm=0.08; YH2=0.051 and LHV=16.43 MJ/kg.
A Novel Method for the Deblurring of Photogrammetric Images Using Conditional Generative Adversarial Networks
- Paweł Burdziakowski
2020 Pełny tekst Remote Sensing
The visual data acquisition from small unmanned aerial vehicles (UAVs) may encounter a situation in which blur appears on the images. Image blurring caused by camera motion during exposure significantly impacts the images interpretation quality and consequently the quality of photogrammetric products. On blurred images, it is difficult to visually locate ground control points, and the number of identified feature points decreases rapidly together with an increasing blur kernel. The nature of blur can be non-uniform, which makes it hard to forecast for traditional deblurring methods. Due to the above, the author of this publication concluded that the neural methods developed in recent years were able to eliminate blur on UAV images with an unpredictable or highly variable blur nature. In this research, a new, rapid method based on generative adversarial networks (GANs) was applied for deblurring. A data set for neural network training was developed based on real aerial images collected over the last few years. More than 20 full sets of photogrammetric products were developed, including point clouds, orthoimages and digital surface models. The sets were generated from both blurred and deblurred images using the presented method. The results presented in the publication show that the method for improving blurred photo quality significantly contributed to an improvement in the general quality of typical photogrammetric products. The geometric accuracy of the products generated from deblurred photos was maintained despite the rising blur kernel. The quality of textures and input photos was increased. This research proves that the developed method based on neural networks can be used for deblur, even in highly blurred images, and it significantly increases the final geometric quality of the photogrammetric products. In practical cases, it will be possible to implement an additional feature in the photogrammetric software, which will eliminate unwanted blur and allow one to use almost all blurred images in the modelling process.