2018 - Repozytorium publikacji - Politechnika Gdańska

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Publikacje z roku 2018

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Variability of relationship between cities and nature in landscape architecture= Zmienność relacji miedzy miastem a naturą na przykładzie architektury krajobrazu miast
- Maura Zaworska
2018
Interpreting and creating the relations between nature and city are the process of learning which is a subject of permanent conceptualization. It is characterized by the culutrality due to human nature and own ability to perceive oneself in the context of the relationship between own environmental and cultural nature. The way of interpreting the nature and providing it with different features affected significantly the development of the image of the cities. Over the centuries, human treated own natural part of the human being as something external, something that needs to be managed and disciplined. The change of mind and perceiving one’s own as a being that is a part of nature and which nature/core is to create the culture, recently led to the reconceptualiation of the relationship between nature and city.
VARIABLE KINEMATICS OF HONING PROCESS – INFLUENCE ON MACHINED WORKPIECE
- Piotr Sender
2018
Surface quality of holes plays an important role in machine manufacturing industry especially in the production of car engines and hydraulic cylinders. Investigations of honing process were carried out by 6 years on horizontal CNC Sunnen’s honing machine HTH 4000S, on vertical conventional honing machine WMW’s SZS 200 and on CNC milling machine of Haas VF 3SS with equipment of Honingtec for honing. Measurements of cylindricity of holes was done on CNC coordinate measuring machine Zeiss Accura, measuring of roughness was done using surface roughness measurement instrument of Mitutoyo SJ-210. The influence of variable kinematics of honing process has a positive impact for many aspects of performing of efficient and accurate honing process.
Variable-fidelity shape optimization of dual-rotor wind turbines
- Thelen Andrew
- Leifsson Leifur
- Sharma Anupam
- Sławomir Kozieł
2018 ENGINEERING COMPUTATIONS
Purpose Dual-rotor wind turbines (DRWTs) are a novel type of wind turbines that can capture more power than their single-rotor counterparts. Because their surrounding flow fields are complex, evaluating a DRWT design requires accurate predictive simulations, which incur high computational costs. Currently, there does not exist a design optimization framework for DRWTs. Since the design optimization of DRWTs requires numerous model evaluations, the purpose of this paper is to identify computationally efficient design approaches. Design/methodology/approach Several algorithms are compared for the design optimization of DRWTs. The algorithms vary widely in approaches and include a direct derivative-free method, as well as three surrogate-based optimization methods, two approximation-based approaches and one variable-fidelity approach with coarse discretization low-fidelity models. Findings The proposed variable-fidelity method required significantly lower computational cost than the derivative-free and approximation-based methods. Large computational savings come from using the time-consuming high-fidelity simulations sparingly and performing the majority of the design space search using the fast variable-fidelity models. Originality/value Due the complex simulations and the large number of designable parameters, the design of DRWTs require the use of numerical optimization algorithms. This work presents a novel and efficient design optimization framework for DRWTs using computationally intensive simulations and variable-fidelity optimization techniques.
Vegetable derived-oil facilitating carbon black migration from waste tire rubbers and its reinforcement effect
- Pan Song
- Chaoying Wan
- Yanling Xie
- Krzysztof Formela
- Shifeng Wang
2018 WASTE MANAGEMENT
Three dimensional chemically cross-linked polymer networks present a great challenge for recycling and reutilization of waste tire rubber. In this work, the covalently cross-linked networks of ground tire rubber (GTR) were degraded heterogeneously under 150 °C due to the synergistic effects of the soybean oil and controlled oxidation. The degradation mechanism was discussed using Horikx theory and Fourier transformation infrared spectroscopy (FTIR). The results showed that the structural evolution of sol and gel parts, which indicated that the sols consisted of degraded GTR chains with low molecular weight, while the gels were mainly composed of bound rubber coated carbon black, which are separated from the cross-linked network of GTR in a high degradation degree. The degraded GTR compound demonstrated an excellent reinforcing effect on solution styrene-butadiene rubber (SSBR), due to the presence of core-shell structured carbon black. This work provide an efficient and economic approach to degrade GTR and transform it into useful products.
Vehicle detector training with labels derived from background subtraction algorithms in video surveillance
- Sebastian Cygert
- Andrzej Czyżewski
2018
Vehicle detection in video from a miniature station- ary closed-circuit television (CCTV) camera is discussed in the paper. The camera provides one of components of the intelligent road sign developed in the project concerning the traffic control with the use of autonomous devices being developed. Modern Convolutional Neural Network (CNN) based detectors need big data input, usually demanding their manual labeling. In the presented research approach the weakly-supervised learning paradigm is used for the training of a CNN based detector em- ploying labels obtained automatically through an application of video background subtraction algorithm. The proposed method is evaluated on GRAM-RTM dataset and a CNN fine-tuned with labels from the background subtraction algorithm. Even though obtained representation in the form of labels may include many false positives and negatives, a reliable vehicle detector was trained employing them. The results are presented showing that such a method can be applied to traffic surveillance systems.
Verification of baffle factor for straight pipe flow
- Wojciech Artichowicz
- Aneta Łuczkiewicz
- Jerzy Sawicki
2018 Pełny tekst Archives of Hydro-Engineering and Environmental Mechanics
During the water disinfection devices designing, it is often assumed that the baffle factor for a straight pipe reactors is equal to one. It would be possible only for the plug flow, which is a simplified model of the flow and does not appear in real situations. The paper contains an equation which enables calculation of the real value of the baffle factor for the pipe flow.
Verification of selected calculation methods regarding shear strength in beams without web reinforcement
- Marta Hirsz
- Krystyna Nagrodzka-Godycka
2018 Pełny tekst MATEC Web of Conferences
The purpose of the article was to compare selected calculation methods regarding shear strength in reinforced concrete beams without web reinforcement. Several calculation methods were tested. This included codes: PN-EN 1992-1-1:2008, ACI 318-14 and fib Model Code for Concrete Structures 2010. The analysis also consists of authorial methods published in technical literature. Calculations of shear strengths were made based on experimental works found in literature. The shear strength ratios Vtest/Vcalc were chosen to be the yardstick of comparison, where Vtest is the experimental shear strength and Vcalc is the calculated shear strength.. A wide range of variables including shear span/depth ratio, compressive strength of concrete, longitudinal steel percentage helped to verify the applicability of calculation methods. Although most of authorial techniques proved to be unstable, they succeeded to show that codes' formulas for shear strength may still be improved. The presented article is a part of Authors' long term research in the matter and a new chapter of their study now concerning beams without web reinforcement.
Verification of the new viscoelastic method of thermal stress calculation in asphalt layers of pavements
- Józef Judycki
2018 International Journal of Pavement Engineering
The new viscoelastic method of thermal stress calculations in asphalt layers has been developed and published recently by the author. This paper presents verification of this method. The verification is based on the comparison of the results of calculations with results of testing of thermal stresses in Thermal Stress Restrained Specimen Test. The calculations of thermal stresses according to the new method were based on rheological parameters of the Burgers model. The parameters were measured in laboratory at different low temperatures, at long time creep under constant loading. Five asphalt mixes were tested. Three of them were high modulus asphalt concretes and two conventional asphalt concretes. Specimens were prepared in exactly the same way both for rheological creep tests and for the Thermal Stress Restrained Specimen Test. The results of measured thermal stresses were compared with thermal stresses calculated from the new viscoelastic method developed by the author and in most cases a good agreement was found. For comparison, the measured stresses were compared with results of calculations according to the existing methods. The viscoelastic Monismith method failed in prediction of thermal stresses. The prediction from the quasi-elastic Hills and Brien method was underestimated, but better than from the Monismith method and worse than from the new viscoelastic method. The reasons of discrepancies were discussed.
Vernacular and neovernacular architecture without a user. Wooden catholic churches in the vicinity of brody in Ukraine.
- Jakub Szczepański
- Agnieszka Szuta
2018
One of the basic theoretical postulates for the protection of monuments is to preserve them in the place of their creation. However, such action is not always possible to implement. The great historical processes of the 20th century led to significant national, political, religious and cultural changes in the border areas between Poland and Ukraine. As a result of those changes, a large number of wooden churches have lost their users. These buildings indicate the development of the skills of using wood as the basic building material through many centuries in the region of today’s borderland of Poland and Ukraine. These above-mentioned churches were built from the Middle Ages up to the 20th century. They were constructed by both rural carpenters and high-class architects. This is a great example of the cultural diversity of the regional heritage. Nevertheless, existence of many of these objects are at risk now. The problem concerns especially the Greek Catholic churches and Orthodox churches in south-eastern Poland. In this region, up to the 1940s Greek Catholics and followers of the Orthodox Church constituted a significant group of citizens but nowadays, they are only a small minority. The situation is similar in western Ukraine, where are only a few Roman Catholic. The article presents three churches which have been deprived of their primary users. They have been located in western Ukraine, near the city of Brody in the villages of: Jazłowczyk, Stanisławczyk and Ruda Brodzka. One of these churches has been saved, as a result of the transfer of the original church to the open-air museum. Unfortunately, it is not possible to preserve the other two buildings.
Versatility of putative aromatic aminotransferases from Candida albicans.
- Kamila Rząd
- Sławomir Milewski
- Iwona Gabriel
2018 Pełny tekst FUNGAL GENETICS AND BIOLOGY
Amino acids constitute the key sources of nitrogen for growth of Candida albicans. In order to survive inside the host in different and rapidly changing environments, this fungus must be able to adapt via its expression of genes for amino acid metabolism. We analysed the ARO8, ARO9, YER152C, and BNA3 genes with regards to their role in the nutritional flexibility of C. albicans. CaAro8p is undoubtedly the most versatile enzyme among the aminotransferases investigated. It is involved in the catabolism of histidine, lysine, and aromatic amino acids as well as in L-Lys, Phe and Tyr biosynthesis. CaAro9p participates in the catabolism of aromatic amino acids and lysine at high concentrations of these compounds, with no biosynthetic role. Conversely, the CaYer152Cp catalytic potential for aromatic amino acid catabolism observed in vitro appears to be of little importance in vivo. Neither biosynthetic nor catabolic roles of CaBan3p were observed for any proteinogenic amino acid. Finally, none of the analysed aminotransferases was solely responsible for the catabolism of a single particular amino acid or its biosynthesis.
Vertical motions damping model test of a lifeboat lowered onto a flat sea surface
- Aleksander Kniat
- Paweł Dymarski
2018 Pełny tekst Polish Maritime Research
The article presents the experiment’s results of the lifeboat model lowered with an initial speed and then released to fall onto a flat water surface. The purpose of the research is to determine the trajectory of the vertical boat motion and describe it with a mathematical model. This is closely related to determining the damping factor since the vertical motion is damped and the lifeboat gets balanced and stops moving after some time. The procedure of selecting parameters in the mathematical model to adjust to the results of the experiment was described in details. The summary describes the imperfections of the presented damping model and their probable causes.
Vertical Temperature Stratification of the Gulf of Gdansk Water
- Grażyna Grelowska
- Eugeniusz Kozaczka
- Dominika Witos-Okrasińska
2018
The Baltic Sea is characterized by variable hydroacoustic conditions, which depend on hydrological conditions throughout the year. The temperature of the water is the factor that has the greatest impact on the changes in the speed of the sound in this basin. Even at a small depth, we can observe a large temperature gradient affecting the accuracy of the conducted research using hydroacoustic devices. A characteristic feature of the Baltic waters is their layering. In the Baltic Sea, we distinguish three main layers of water: surface, whose temperature is closely related to air temperature and varies within 1-22 degrees during the year, an intermediate characterized by the occurrence of a seasonal thermocline and deep sea temperature, which fluctuates within small limits from 4-6 degrees. There are many factors influencing water temperature changes, among others: heat exchange between water and atmosphere, floods of water with higher salinity from the North Sea, strong winds occurring in the autumn-winter period, an upwelling phenomenon, inflow of fresh waters from rivers. The paper presents the results of research carried out in the Gulf of Gdansk and their impact on the acoustic conditions of the Baltic waters.
Vibration testing in buildings and safety of their operation
- Anna Jakubczyk-Gałczyńska
- Agata Siemaszko
2018 Pełny tekst Scientific Journal of the Military University of Land Forces
The paper presents the issue of vibrations in residential buildings located near roads. It describes the measurement methodology and criteria for assessing the impact of vibrations generated by passing trucks. The article specifies a method to establish the impact on the operation of the examined facilities and it promotes the idea of employing a Bayesian network to determine probabilistically the level of risk to single-family houses.
Video Classification Technology in a Knowledge-Vision-Integration Platform for Personal Protective Equipment Detection: An Evaluation
- Caterine De
- Cesar Sanin
- Edward Szczerbicki
2018
This work is part of an effort for the development of a Knowledge-Vision Integration Platform for Hazard Control (KVIP-HC) in industrial workplaces, adaptable to a wide range of industrial environments. This paper focuses on hazards resulted from the non-use of personal protective equipment (PPE), and examines a few supervised learning techniques to compose the proposed system for the purpose of recognition of three protective equipment: hard hat, gloves and boots. In the KVIP-HC, classifiers, feature images and any context information are represented explicitly using the Set of Experience Knowledge Structure (SOEKS), grouped and stored as Decisional DNA (DDNA). The collected knowledge is used for reasoning and to reinforce the system from time to time, customizing the service according to each scenario and application. Therefore, in choosing the classification methodology that best suits the application, processing time for training (once the system will be eventually reinforced in real time), accuracy, detection time and the predictor sizes (for the purpose of storing data) are analyzed to propose the most reasonable candidates to compose the platform.
Virtual spring damper method for nonholonomic robotic swarm self-organization and leader following
- Jakub Wiech
- Victor Eremeev
- Ivan Giorgio
2018 Pełny tekst CONTINUUM MECHANICS AND THERMODYNAMICS
In this paper, we demonstrate a method for self-organization and leader following of nonholonomic robotic swarm based on spring damper mesh. By self-organization of swarm robots we mean the emergence of order in a swarm as the result of interactions among the single robots. In other words the self-organization of swarm robots mimics some natural behavior of social animals like ants among others. The dynamics of two-wheel robot is derived, and a relation between virtual forces and robot control inputs is defined in order to establish stable swarm formation. Two cases of swarm control are analyzed. In the first case the swarm cohesion is achieved by virtual spring damper mesh connecting nearest neighboring robots without designated leader. In the second case we introduce a swarm leader interacting with nearest and second neighbors allowing the swarm to follow the leader. The paper ends with numeric simulation for performance evaluation of the proposed control method.
Visible light photocatalysis employing TiO2/SrTiO3-BiOI composites: Surface properties and photoexcitation mechanism
- Martyna Marchelek
- Ewelina Grabowska
- Tomasz Klimczuk
- Wojciech Lisowski
- Paweł Mazierski
- Adriana Zaleska-Medynska
2018 Molecular Catalysis
A series of binary TiO2/SrTiO3 and ternary TiO2/SrTiO3_BiOI composites have been synthesized using multistep preparation method. Characterization of the obtained photocatalysts covered complex analysis including morphology + y (SEM), BET specific surface area, porosity, optical properties (DRS), chemical composition of surface (XPS), crystal structure and crystal size (XRD). UV–vis and Vis ligh induced photocatalytic activity was investigated in the model reaction of phenol degradation in the aqueous phase. The powder TiO2/SrTiO3_BiOI ternary composites exhibited a new photocatalytic properties and could be used in the heterogeneous photocatalysis processes. The photocatalytic activity observed in the phenol degradation reaction significantly increased under the visible light range irradiation. The best photocatalytic activity was observed for the TiO2/SrTiO3_BiOI_4 sample, about 30.2 % of phenol was decomposed after 1 h of visible light irradiation. The utilization of the nanolayered materials facilitates the separation of photocatalysts from the aqueous phase. Moreover, the composite was easily reused without the significant decrease of the photocatalytic activity in three subsequent cycles. After 5 h of Vis irradiation of the isotopically labeled (1-13C) phenol solution in the presence of the TiO2/SrTiO3_BiOI_4 composite, the salicylic, maleic, fumaric and malonic acids were detected using GC–MS equipment. The identification of degradation by-products led to clarification of phenol decomposition pathway. The role of active species during the decomposition process of organic compound was investigated using different types of active species scavengers.
Visual and Auditory Attention Stimulator for Assisting Pedagogical Therapy
- Łukasz Kosikowski
- Andrzej Czyżewski
- Andrzej Senderski
2018 Pełny tekst
Visual and auditory attention stimulator provides a system developed in order to improve reading skills using simultaneous presentation of text in its visual form and in transformed auditory form accompanied by related movie material. The described research employed 40 children at the age of 8 13 years having difficulties in learning of reading, who were diagnosed as having developmental dyslexia. It was shown that application of the proposed method could improve reading skills in those children. The effectiveness of the method has been shown primarily using the D2 attention test designed by R. Brickenkamp in its Polish adaptation made by E. Dajek.
Visual Management as the support in building the concept of continuous improvement in the enterprise
- Adam Lewiński
2018 Pełny tekst Przedsiębiorczość i Zarządzanie
The following article presents one of the selected tools of the Lean Management concept – visual management. This method enables enterprises to strengthen their process of continuous improvement. Due to the support of visual management, it is possible to manage information more effectively by the managerial board and to improve communication process within in the particular company. In the first part, the author describes the concept of Lean Management. Then the idea of continuous improvement is explained, which is the fundament of this Japanese management concept. In the third part, the author presents the visual management in its business environment. The last part of the paper tackles the tools, firmly based on the visual management, that function in the manufacturing enterprises surveyed by the author.
Visual method for detecting critical damage in railway contact strips
- Sławomir Judek
- Jacek Skibicki
2018 Pełny tekst MEASUREMENT SCIENCE & TECHNOLOGY
Ensuring an uninterrupted supply of power in the electric traction is vital for the safety of this important transport system. For this purpose, monitoring and diagnostics of the technical condition of the vehicle's power supply elements are becoming increasingly common. This paper presents a new visual method for detecting contact strip damage, based on measurement and analysis of the movement of the overhead contact line (OCL) wire. A measurement system configuration with a 2D camera was proposed. The experimental method has shown that contact strips damage can be detected by transverse displacement signal analysis. It has been proven that the velocity signal numerically established on that basis has a comparable level in the case of identical damage, regardless of its location on the surface of the contact strip. The proposed method belongs to the group of contact-less measurements, so it does not require interference with the structure of the catenary network nor the mounting of sensors in its vicinity. Measurement of displacements of the contact wire in 2D space makes it possible to combine the functions of existing diagnostic stands assessing the correctness of the mean contact force control adjustment of the current collector with the elements of the contact strip diagnostics, which involves detecting their damage which may result in overhead contact line rupture.
Visual perception of vowels from static and dynamic cues
- Arkadiusz Rojczyk
- Tomasz Ciszewski
- Grzegorz Szwoch
- Andrzej Czyżewski
2018 Journal of the Acoustical Society of America
The purpose of the study was to analyse human identification of Polish vowels from static and dynamic durationally slowed visual cues. A total of 152 participants identified 6 Polish vowels produced by 4 speakers from static (still images) and dynamic (videos) cues. The results show that 59% of static vowels and 63% of dynamic vowels were successfully identified. There was a strong confusion between vowels within front, central, and back classes. Finally, correct identification strongly depended on speakers, showing that speakers differ significantly in how “clearly” they produce vowel configurations