2020 - Repozytorium publikacji - Politechnika Gdańska

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Nested Kriging with Variable Domain Thickness for Rapid Surrogate Modeling and Design Optimization of Antennas
- Anna Pietrenko-Dąbrowska
- Sławomir Kozieł
2020 Pełny tekst Electronics
Design of modern antennas faces numerous difficulties, partially rooted in stringent specifications imposed on both electrical and field characteristics, demands concerning various functionalities (circular polarization, pattern diversity, band-notch operation), but also constraints imposed upon the physical size of the radiators. Conducting the design process at the level of full-wave electromagnetic (EM) simulations, otherwise dictated by reliability, entails considerable computational expenses, which is another and a serious challenge. It is especially pronounced for the procedures involving repetitive EM analyses, e.g., parametric optimization. Utilization of fast surrogate models as a way of mitigating this issue has been fostered in the recent literature. Unfortunately, construction of reliable surrogates for antenna structures is hindered by their highly nonlinear responses and even more by the utility requirements: design-ready models are to be valid over wide ranges of operating conditions and geometry parameters. Recently proposed performance-driven modeling, especially the nested kriging framework, addresses these difficulties by confining the surrogate model domain to a region that encapsulates the designs being optimum with respect to the relevant figures of interest. The result is a dramatic reduction of the number of training samples needed to render a usable model. This paper introduces a variable-thickness domain, which is an important advancement over the basic nested kriging. The major benefit demonstrated using two antenna examples is a further and significant (up to seventy percent) reduction of the training data acquisition cost. It is achieved while ensuring that the model domain covers the regions containing optimum designs for various sets of performance specifications.
Neural Architecture Search for Skin Lesion Classification
- Arkadiusz Kwasigroch
- Michał Grochowski
- Agnieszka Mikołajczyk
2020 Pełny tekst IEEE Access
Deep neural networks have achieved great success in many domains. However, successful deployment of such systems is determined by proper manual selection of the neural architecture. This is a tedious and time-consuming process that requires expert knowledge. Different tasks need very different architectures to obtain satisfactory results. The group of methods called the neural architecture search (NAS) helps to find effective architecture in an automated manner. In this paper, we present the use of an architecture search framework to solve the medical task of malignant melanoma detection. Unlike many other methods tested on benchmark datasets, we tested it on practical problem, which differs greatly in terms of difficulty in distinguishing between classes, resolution of images, data balance within the classes, and the number of data available. In order to find a suitable network structure, the hill-climbing search strategy was employed along with network morphism operations to explore the search space. The network morphism operations allow for incremental increases in the network size with the use of the previously trained network. This kind of knowledge reusing allows significantly reducing the computational cost. The proposed approach produces structures that achieve similar results to those provided by manually designed structures, at the same time making use of almost 20 times fewer parameters. What is more, the search process lasts on average only 18h on single GPU.
Neural network based algorithm for hand gesture detection in a low-cost microprocessor applications
- Tomasz Kocejko
- Filip Brzezinski
- Jacek Rumiński
- Artur Poliński
- Jerzy Wtorek
2020
In this paper the simple architecture of neural network for hand gesture classification was presented. The network classifies the previously calculated parameters of EMG signals. The main goal of this project was to develop simple solution that is not computationally complex and can be implemented on microprocessors in low-cost 3D printed prosthetic arms. As the part of conducted research the data set EMG signals corresponding to 5 different gestures was created. The accuracy of elaborated solution was 90% when applied real time on data sampled with 1kHz frequency and 75% when applied real time on data acquired and process directly on microprocessor with lower,100Hz sampling frequency.
Neural Network Subgraphs Correlation with Trained Model Accuracy
- Izajasz Wrosz
2020
Neural 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 of subgraphs and the network’s final test accuracy by analyzing a dataset of convolutional neural networks trained for image recognition. We also consider a subgraph based network distance measure and suggest opportunities for improved NAS algorithms that could benefit from our observations.
New Approaches for Escherichia coli Genotyping
- Roman Kotłowski
- Katarzyna Grecka
- Barbara Kot
- Piotr Szweda
2020 Pełny tekst Pathogens
Easy-to-perform, fast, and inexpensive methods of differentiation of Escherichia coli strains beyond the species level are highly required. Herein two new, original tools for genotyping of E. coli isolates are proposed. The first of the developed method, a PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) test uses a highly variable fliC gene, encoding the H antigen as a molecular target. The designing of universal pair of primers and selection of the optimal restriction enzyme RsaI was preceded by in silico comparative analysis of the sequences of the genes coding for 53 different serotypes of H-antigen (E. coli flagellin). The target fragments of E. coli genomes for MLST method were selected on the basis of bioinformatics analysis of complete sequences of 16 genomes of E. coli. Initially, seven molecular targets were proposed (seven pairs of primers) and five of them were found useful for effective genotyping of E. coli strains. Both developed methods revealed high differentiation power, and a high genetic diversity of the strains tested was observed. Within the group of 71 strains tested, 29 and 47 clusters were revealed with fliC RFLP-PCR and MLST methods, respectively. Differentiation of the strains with the reference BOX-PCR method revealed 31 different genotypes. The in silico analysis revealed that the discriminatory power of the new MLST method is comparable to the Pasteur and Achtman schemes and is higher than the discriminatory power of the method developed by Clermont. From the epidemiology point of view, the outcomes of our investigation revealed that in most cases, the patients were infected with unique strains, probably from environmental sources. However, some strains isolated from different patients of the wards of pediatrics, internal medicine, and neurology were classified to the same genotype when the results of all three methods were taken into account. It could suggest that they were transferred between the patients.
New Challenges in Management and Economics in 21st century. Selected studies and examples
- Piotr Grudowski
- Dariusz Dudek
- Julita Majczyk
- Mateusz Muchlado
2020
In Chapter 1 authors describe the method used to assess the level of readiness of an organization to introduce the Lean Six Sigma concept supporting the Quality 4.0 assumptions, which is gaining more and more interest not only in large organizations, but also in the SME sector. Its use will be illustrated by the example of a small service company. Chapter 2 presents the characteristics of blockchain technology applications in the modern economy. Particular attention was paid to aspects such as security, staff issues and trust. Chapter 3 deals with the entrepreneurship of immigrants from the Far East. Patterns of approaches leading to strategy choices implemented by the immigrants were presented as well as processes of defining customers and factors influencing the choice between an ethnic and local business, immigrants' approaches to building market position and development. In this diverse way, the authors wanted to indicate how many factors can determine the effectiveness and efficiency of various organizations in the age of Industry 4.0. Only knowledge of management and economics that is wide and open to various challenges will allow executives to successfully face contemporary and future risks.
New pathways for functionalization of phosphorus ligands
- Anna Ordyszewska
2020
The presented dissertation consistsof two main partsand focuses on the synthesis and characterization of new low-valent phosphorus compounds. Thesestudies have already been fully described in three JCR-journals. The first partdescribes the utilization ofselectedphosphanylphosphinidene transition metal complexes as a source of diversified phosphorus ligands. For thispurposethree complexes havebeenchosen:[(DippN)2(Cl)W(η2-tBu2P-P)][Li(dme)3], [(pTol3P)2Pt(η2-tBu2P=P)], and [(dppe)Pt(η2-tBu2P=P)]. The reactivity of these complexes toward terminal dihaloalkanes and chalcogens was taken under investigation. As a result, new complexes with a variety of phosphorusmoietiessuch astBu2PP-R (R = Me, I, (CH2)3Br, (CH2)nPPtBu2 (n = 4, 6), PPtBu2 )ortBu2P-P-Se, tBu2P(Se)-P, tBu2P-P-P andtBu2P(S)-P-P-PtBu2were obtained.In the second part a new family of diphosphinoboraneswas synthesized that contain not only phosphorus but also boron atom in the structure. Diphosphinoboranes(R2P)2BR’were formed as a result of the reactions of selected lithium phosphides R2PLi (R2P=tBu2P, Cy2P, Ph2P,tBuPhP) and dibromoboranes R’BBr2(R’ = NiPr2, Ph). Theycan be classified in three different groups depending on their electronic and structural properties. The amino(diphosphino)borane(Ph2P)2BNiPr2has also been proven to actaschelating ligand in the reaction with CODPtMe2.
New synthesis route of highly porous InxCo4Sb12 with strongly reduced thermal conductivity
- N. Gostkowska-Lekner
- B. Trawinski
- A. Kosonowski
- Beata Bochentyn
- Marcin Lapinski
- Tadeusz Miruszewski
- Krzysztof W. Wojciechowski
- Bogusław Kusz
2020 Pełny tekst JOURNAL OF MATERIALS SCIENCE
Highly porous, In-filled CoSb3 skutterudite materials with an attractive thermoelectric figure of merit (ZT * 1) and corresponding dense samples were fabricated through the cost-effective method of reduction in oxides in dry hydrogen and the pulsed electric current sintering (PECS) method, respectively. The reduction process was described in detail using in situ thermogravimetric analysis of Co2O3, Sb2O3 and In(NO3)35H2O separately and in a mixture. Two methods to synthesise the same material were examined: (a) free sintering of an initially reduced powder and (b) PECS. The free-sintered materials with higher porosities (up to * 40%) exhibited lower values of electrical conductivity than the dense PECS samples (porosity up to * 5%), but the benefit of an even sixfold reduction in thermal conductivity resulted in higher ZT values. The theoretical values of thermal conductivity for various effective media models considering randomly oriented spheroid pores are in good agreement with the experimental thermal conductivity data. The assumed distribution and shape of the pores correlated well with the scanning electron microscope analysis of the microstructure. The lowest value of thermal conductivity, equal to 0.5 W/m K, was measured at 523 K for In0.1Co4Sb12 with 41% porosity. The highest value of ZT max = 1.0 at 673 K was found for the In0.2Co4Sb12 sample in which the porosity was 36%
New Unsymmetrical Bisacridine Derivatives Noncovalently Attached to Quaternary Quantum Dots Improve Cancer Therapy by Enhancing Cytotoxicity toward Cancer Cells and Protecting Normal Cells
- Joanna Pilch
- Edyta Matysiak-Brynda
- Agata Kowalczyk
- Piotr Bujak
- Zofia Mazerska
- Anna M. Nowicka
- Ewa Augustin
2020 ACS Applied Materials & Interfaces
The use of nanoparticles for the controlled drug delivery to cells has emerged as a good alternative to traditional systemic delivery. Quantum dots (QDs) offer potentially invaluable societal benefits such as drug targeting and in vivo biomedical imaging. In contrast, QDs may also pose risks to human health and the environment under certain conditions. Here, we demonstrated that unique combination of nanocrystals core components (Ag-In-Zn-S) would eliminate the toxicity problem and increases their biomedical applications. The alloyed quaternary nanocrystals Ag-In-Zn-S (QDgreen: Ag1.0In1.2Zn5.6S9.4 and QDred: Ag1.0In1.0Zn1.0S3.5) were used to transport new unsymmetrical bisacridine derivatives (UAs: C-2028 and C-2045) into lung H460 and colon HCT116 cancer cells for improving the cytotoxic and antitumor action of these compounds. UAs were coupled with QD through physical adsorption. The obtained results clearly indicate that the synthesized nanoconjugates exhibited higher cytotoxic activity than unbound compounds, especially towards lung H460 cancer cells. Importantly, unsymmetrical bisacridines non-covalently attached to QD strongly protect normal cells from the drug action. It is worth to point out that QDgreen or QDred without UAs did not influence the growth of cancer as well as normal cells what is consistent with in vivo results. In non-cellular systems, at pH 5.5 and 4.0, which relates to the conditions of endosomes and lysosomes, the UAs released from QD-UAs nanoconjugates. An increase of total lysosomes content was observed in H460 cells treated with QDs-UAs what can affect the release of the UAs from the conjugates. Moreover, confocal laser scanning microscopy analyses revealed that QD-UAs nanoconjugates enter to H460 cells more efficiently than to HCT116 and normal cells, which may be the reason of their higher cytotoxicity against lung cancer. Summarizing, the non-covalent attachment of UAs to QDs increases the therapeutic efficiency of UAs, by improving cytotoxicity toward lung H460 cancer cells and having protecting effects on normal cells.
New uranium(vi) and isothiouronium complexes: synthesis, crystal structure, spectroscopic characterization and a DFT study
- Ewelina Grabias
- Bogdan Tarasiuk
- Anna Dołęga
- Marek Majdan
2020 CRYSTENGCOMM
The crystal structures of S,S′-2,5-dimethylbenzene-1,4-diylbis(methylisothiouronium) diacetate (1_ac), S,S′-2,5-dimethylbenzene-1,4-diylbis(methylisothiouronium) dichloride (1_Cl), 1_U complex, S,S′-naphthalene-1,4-diylbis(methylisothiouronium) dichloride (2_Cl), and 2_U complex were determined for the first time. The supramolecular structures of the compounds obtained are mainly based on hydrogen bonding and ionic interactions between the isothiouronium cations and the counter anions Cl−, CH3COO−, and [UO2(CH3COO)3]−. Their structural and spectroscopic properties were studied, and the results of DFT calculations were compared with the experimental findings to provide insights into the properties of these new compounds. The DFT calculations indicate a strong preference for the formation of the outer-sphere complex (ion-pair) between the uranyl species and an isothiouronium cation, and very large stabilization energies of the interactions, which can be utilized for the selective binding of U(VI). The compounds obtained are the first f-element and isothiouronium salt complexes described so far.
Newton’s Method for the McKendrick-von Foerster Equation
- Agnieszka Bartłomiejczyk
- Monika Wrzosek
2020
In the paper we study an age-structured model which describes the dynamics of one population with growth, reproduction and mortality rates. We apply Newton’smethod to the McKendrick-von Foerster equation in the semigroup setting. We prove its first- and second-order convergence.
Ni/cerium Molybdenum Oxide Hydrate Microflakes Composite Coatings Electrodeposited from Choline Chloride: Ethylene Glycol Deep Eutectic Solvent
- Juliusz Winiarski
- Anna Niciejewska
- Jacek Ryl
- Kazimierz Darowicki
- Sylwia Baśladyńska
- Katarzyna Winiarska
- Bogdan Szczygieł
2020 Pełny tekst Materials
Cerium molybdenum oxide hydrate microflakes are codeposited with nickel from a deep eutectic solvent-based bath. During seven days of exposure in 0.05 M NaCl solution, the corrosion resistance of composite coating (Ni/CeMoOxide) is slightly reduced, due to the existence of some microcracks caused by large microflakes. Multielemental analysis of the solution, in which coatings are exposed and the qualitative changes in the surface chemistry (XPS) show selective etching molybdenum from microflakes. The amount of various molybdenum species within the surface of coating nearly completely disappear, due to the corrosion process. Significant amounts of Ce3+ compounds are removed, however the corrosion process is less selective towards the cerium, and the overall cerium chemistry remains unchanged. Initially, blank Ni coatings are covered by NiO and Ni(OH)2 in an atomic ratio of 1:2. After exposure, the amount of Ni(OH)2 increases in relation to NiO (ratio 1:3). For the composite coating, the atomic ratios of both forms of nickel vary from 1:0.8 to 1:1.3. Despite achieving lower corrosion resistance of the composite coating, the applied concept of using micro-flakes, whose skeleton is a system of Ce(III) species and active form are molybdate ions, may be interesting for applications in materials with potential self-healing properties.
Nieniszczące badania stalowych konstrukcji obiektów budowlanych
- Dariusz Kowalski
2020
W miarę powszechne jest wykonywanie badań nieniszczących w zakresie wytwarzania elementów i obiektów o konstrukcji stalowych. Wynika to z potrzeby właściwego kontrolowania materiału stalowego poddawanego przetwarzaniu i łączeniu za pomocą technik spawalniczych. Badania nieniszczące związane są też z wykonywaniem zabezpieczeń antykorozyjnych, które chronią nasz materiał przed jego przyspieszoną degradacją w warunkach jakim przychodzi nam eksploatować konstrukcje stalowe. Badania materiału, połączeń spawanych, całych konstrukcji czy też powłok antykorozyjnych wykonywane są przede wszystkim w fazie wytwarzania, montażu i odbioru. Nader często w życiu inżynierskim przychodzi nam te same techniki badawcze stosować w sposób kompleksowy czy też wybiórczy do badania obiektów już eksploatowanych, które albo uległy awariom, zniszczeniom lub też nastąpiła ich degradacja, zużycie eksploatacyjne czy też korozyjne lub występują w nich określone problemy eksploatacyjne, np. drgania konstrukcji. Nie sposób, w niniejszym materiale, przedstawić wszystkie badania które są możliwe do wykonania w ramach produkcji materiału, wytwarzania konstrukcji czy też ich zabezpieczania dlatego, że czynniki i potrzeby tych badań są bardzo różne, tak jak różne metody możemy do tych działań zastosować. W badaniach obiektów lub ich określonych części często stosujemy nieznormalizowane, metody innowacyjne. W materiale niniejszym przedstawiono podstawowe wymagania normowe oraz badania odbiorowe w zakresie wytwarzania konstrukcji stalowych spawanych oraz badania z zakresu powłok.
Nietypowa podziemna konstrukcja oporowa w technologii DSM jako zabezpieczenie głębokiej wymiany gruntu
- Grzegorz Horodecki
2020
W artykule przedstawiono nietypowe rozwiązanie podparcia i zabezpieczenia głębokiej wymiany gruntu z zastosowaniem przestrzennej konstrukcji oporowej w technologii DSM, ze względu na ograniczenie miejsca oraz zapewnienie stateczności nasypu drogowego. Opisano również realizację rozwiązania oraz prowadzony monitoring geotechniczny.
Nikola Tesla i jego wynalazki
- Dariusz Świsulski
2020 Wiadomości Elektrotechniczne
Przedstawiono biografię Nikoli Tesli. Omówiono dziedziny, którymi się zajmował i opisano najważniejsze wynalazki.
Nitrogen removal in vertical flow constructed wetlands: influence of bed depth and high nitrogen loadings
- Adelaide Almeida
- Krzysztof Jóźwiakowski
- Alina Kowalczyk-Juśko
- Piotr Bugajski
- Karolina Kurek
- Fátima Carvalho
- Anabela Durao
- Carlos Ribeiro
- Magdalena Gajewska
2020 ENVIRONMENTAL TECHNOLOGY
The aim of the study was to evaluate the nitrogen removal and its eﬀects on the plant’s growth and leaves morphology. using two subsurface vertical ﬂow (VF bed), with different depths (0.24 m2 × 0.70 m; 0.24 m2 × 0.35 m) and nitrogen load increments. The VF bed were planted with Vetiveria zizanioides, ﬁlled with light expanded clay aggregates (Leca®NR 10/20) and fed in parallel mode with synthetic wastewater. High ammonium nitrogen concentration ([NH4+–N] from 68 ± 3 to 290 ± 8 mg L−1) was used without toxicity symptoms in plants, although the eﬀects of ammonium nitrogen load were stopped the growth of the plants. Signiﬁcant diﬀerences between ammonium nitrogen removed in each VF bed obtained for total nitrogen (TNinﬂ.) ≥ 27 ± 0.8 g m−2 d−1. The nitriﬁcation was contributed to ammonium nitrogen removal because was found higher values of nitrate and nitrite in the eﬄuent. These values were more higher in VF bed 1 than in the VF bed 2, since ammonium nitrogen removal were also more higher in VF bed 1 than in the VF bed 2. Total nitrogen mass balance was carried out and the results show that the nitriﬁcation/denitriﬁcation process occurred with nitrogen plants uptake. It was observed that the VF bed depth has an inﬂuence on all nitrogen removal processes. As higher the depth root system it is seemed to favour the creation of zones with diﬀerent oxidations conditions that allow the nitrogen compounds to be removed intensively.
NLP Questions Answering Using DBpedia and YAGO
- Tomasz Boiński
- Julian Szymański
- Bartłomiej Dudek
- Paweł Zalewski
- Szymon Dompke
- Maria Czarnecka
2020 Pełny tekst Vietnam Journal of Computer Science
In this paper, we present results of employing DBpedia and YAGO as lexical databases for answering questions formulated in the natural language. The proposed solution has been evaluated for answering class 1 and class 2 questions (out of 5 classes defined by Moldovan for TREC conference). Our method uses dependency trees generated from the user query. The trees are browsed for paths leading from the root of the tree to the question subject. We call those paths fibers and they represent the user intention. The question analysis consists of three stages: query analysis, query breakdown and information retrieval. The aim of those stages is the detection of the entities of interest and its attributes, indicating the users’ domain of interest. The user query is then converted into a SPARQL query and sent to the DBpedia and YAGO databases. The baseline and the extended methods are presented and the quality of the solution is evaluated and discussed.
Nonadaptive estimation of the rotor speed in an adaptive full order observer of induction machine
- Marcin Morawiec
- Paweł Kroplewski
2020 Pełny tekst Bulletin of the Polish Academy of Sciences-Technical Sciences
The article proposes a new method of reproducing the angular speed of the rotor of a cage induction machine designed for speed observers based on the adaptive method. In the proposed solution, the value of the angular speed of the rotor is not determined by the classical law of adaptation using the integrator only by an algebraic relationship. Theoretical considerations were confirmed by simulation and experimental tests.
Non-compulsory practical education programme for modernist heritage
- Anna Orchowska-Smolińska
2020 Pełny tekst World Transactions on Engineering and Technology Education
A non-compulsory programme for students of architecture that contains more specialised topics beyond the basic subjects is an important educational tool. The advantages include classes in smaller groups, the possibility of practical exercises in real field conditions and the benefits of meeting professional practitioners. This type of programme is particularly useful for teaching architectural heritage of the 20th Century, its protection and conservation; this knowledge is not widespread. The topic is current and there have been numerous developments over the years. The aims outlined in this article are to present the scope of this non-compulsory programme, including the interactive field classes, workshops and summer school. The benefits of this practically oriented programme are confirmed by the results achieved.
Non-Destructive Testing of the Longest Span Soil-Steel Bridge in Europe—Field Measurements and FEM Calculations
- Mikołaj Miśkiewicz
- Bartosz Sobczyk
- Paweł Tysiąc
2020 Pełny tekst Materials
The article describes interdisciplinary and comprehensive non-destructive diagnostic tests of final bridge inspection and acceptance proposed for a soil-steel bridge made of corrugated sheets, being the European span length record holder (25.74 m). As an effect of an original concept a detailed and precise information about the structure short-term response was collected. Periodic diagnostics of bridge deformations was done one year after it was built. Load test design was based on numerical simulations performed by means of finite element method (FEM). In situ measurements were done with the aid of: inductive sensors, optical total station, and terrestrial laser scanner. The results produced by terrestrial laser scanning were used to build a precise image of structure deformation in 3D space during the tests. The accuracy of laser mapping was significantly increased using the information coming from total station and inductive sensors. These have higher accuracy and therefore can be used as reference. Thus, new quality in measurements is introduced. Good correspondence between in situ values and FEM estimations was achieved. Therefore, such a combination of testing methods can be used in non-destructive diagnostics of structures and is an interesting alternative for the standard approach, in which the measurements are done in limited number of points.