displaying 1000 best results Help
Search results for: pervious concrete
-
Multidisciplinary Open System Transferring Knowledge for R2B Development
PublicationDespite many efforts, there is still a serious problem in transferring knowledge from research to business. The problem is especially visible in Poland – the cooperation of R2B is ineffective. We are trying to solve this problem using some IT support. The manuscript presents some solutions developed at the Gdańsk University of Technology. In particular, the platform called “MOST Knowledge” is deeply described. Its layer architecture,...
-
Bistability in a One-Dimensional Model of a Two-Predators-One-Prey Population Dynamics System
PublicationIn this paper, we study a classical two-predators-one-prey model. The classical model described by a system of three ordinary differential equations can be reduced to a one-dimensional bimodalmap. We prove that this map has at most two stable periodic orbits. Besides, we describe the bifurcation structure of the map. Finally, we describe a mechanism that leads to bistable regimes. Taking this mechanism into account, one can easily...
-
The importance of the bottom layer in double-layer porous asphalt for noise reduction
PublicationDouble-layer porous asphalt concrete (DPAC) surfaces are generally considered to be the acoustically most effective low noise road surfaces ready for implementation. While DPAC used on highways in warm climates may have an average life of around 8 years, in Scandinavia with severe winter climate DPAC usually survive only about 3 years; partly due to wear of studded tyres. An ongoing project in Sweden, applying DPAC and single-layer...
-
Analiza przyczepności prętów żebrowanych w betonie metodą pull-out na próbkach centrycznych i mimośrodowych
PublicationArtykuł dotyczy analizy przyczepności żebrowanego stalowego pręta zbrojeniowego w betonie. Celem pracy była ocena wpływu położenia pręta w betonowym bloku na lokalną zależność naprężenie przyczepności-poślizg. Podjęto także próbę numerycznej symulacji przeprowadzonych eksperymentów w programie ABAQUS. Analizę doświadczalną przeprowadzono za pomocą testu pull-out na dwóch rodzajach próbek – centrycznych i mimośrodowych w dwóch wariantach,...
-
Niezgodność przekonań i działań menedżerów wobec pracowników w wieku 55+
PublicationArtykuł dotyczy problematyki postaw i działań menadżerów wobec pracowników w wieku 55+. W literaturze dotyczącej zarządzania wiekiem przytaczane są wyniki badań na temat cech charakteryzujących starszych pracowników. Porównuje się je czasami z cechami przypisywanymi pracownikom młodym. Cel prezentowanych w artykule badań sformułowany został nieco inaczej i dotyczył zweryfikowania zbieżności zalet przypisywanych starszym pracownikom...
-
Selektywne chłodzenie mózgu noworodka po Niedotlenieniu okołoporodowym. Część 1. Medyczne fakty oraz przegląd dostępnych rozwiązań systemów selektywnego chłodzenia mózgu
PublicationMózg ludzki jest organem delikatnym, dlatego tak ważne jest zadbanie o to, aby już w momencie przyjścia na świat noworodek miał zapewnioną, w razie konieczności możliwość minimalizacji uszkodzeń neurologicznych, spowodowanych niedotlenieniem okołoporodowym. Niedotlenienie to w dramatyczny sposób zaburza homeostazę mózgu, który jako organ najbardziej energochłonny potrzebuje najwięcej tlenu. Zapoczątkowane brakiem tlenu procesy...
-
Die Sandgrube „Köplitz“ – ein interessanter geologischer Aufschluss am Nordwestrand der Schmiedeberger Stauchendmoräne
PublicationDie Kiessandgrube Köplitz ermöglicht einen Einblick in die komplizierten, durch glazidynamische Überprägung gekennzeichneten geologischen Lagerungsverhältnisse im Bereich der Schmiedeberger Stauchendmoräne. Anhand neuer Geländedokumentationen wird ein kleiner Eindruck vom komplizierten injektiven „Fließfalten-Schuppenbau“ der Stauchendmoräne vermittelt. Die steil aufgerichteten, aus tertiären (Untermiozän bis Oligozän) und quartären...
-
El empleo en el marco de la transformación digital: Gig Economy vs Open Collaboration ¿dos caras de una misma moneda?
PublicationTal y como plantea Pérez [43, 44], estamos viviendo los efectos de una revolución tecnológica ligada al desarrollo de las TICs. Los procesos de innovación, describe, se retroalimentan colectivamente, involucrando diferentes actores (productores, proveedores, distribuidores y consumidores) entrelazados en clústeres o redes dinámicas y complejas. Estos procesos colectivos ayudan a desarrollar e implementar tecnologías y magnifican...
-
WYBRANE WŁAŚCIWOŚCI FIZYCZNO-CHEMICZNE MIKROSFER I MOŻLIWOŚĆ ICH WYKORZYSTANIA W KOMPOZYTACH CEMENTOWYCH : The selected physico-chemical properties of microspheres and possibility of their use in cement composites
PublicationMicrospheres are formed during the mineral transformation stage in coal combustion. Their content in fly ashes from the combustion of different types of coals varies over a rather wide range from 0.01 to 4.8 wt.%. The microspheres have three main elements, silicon, aluminum and iron, the oxides of which account for about 89.0 wt.% of the material. Mineralogical analysis using XRD shows that microspheres mainly contain mullite and...
-
Neoplasm, malignant - Male, 59 - Tissue image [5100730008369191]
Open Research DataThis is the histopathological image of SPINAL CORD, CRANIAL NERVES, AND OTHER PARTS OF CENTRAL NERVOUS SYSTEM tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.
-
An advanced tool integrating failure and sensitivity analysis into novel modeling of the stormwater flood volume
PublicationAn innovative tool for modeling the specific flood volume was presented that can be applied to assess the need for stormwater network modernization as well as for advanced flood risk assessment. Field measurements for a catchment area in Kielce, Poland, were used to apply the model and demonstrate its usefulness. This model extends the capability of recently developed statistical and machine learning hydrodynamic models developed...
-
Reverberation divergence in VR applications
PublicationThe aim of this project was to investigate the correlation between virtual reality (VR) imagery and ambisonic sound. With the increasing popularity of VR applications, understanding how sound is perceived in virtual environments is crucial for enhancing the immersiveness of the experience. By examining the relationship between visual scenes and sound scenes, this research attempts to explore how the interaction between vision and...
-
Minimization of the number of periodic points for smooth self-maps of simply-connected manifolds with periodic sequence of Lefschetz numbers
PublicationLet f be a smooth self-map of m-dimensional, m ≥ 4, smooth closed connected and simply-connected manifold, r a fixed natural number. For the class of maps with periodic sequence of Lefschetz numbers of iterations the authors introduced in [Graff G., Kaczkowska A., Reducing the number of periodic points in smooth homotopy class of self-maps of simply-connected manifolds with periodic sequence of Lefschetz numbers, Ann. Polon. Math....
-
On the modelling of aerodynamic force coefficients for over-shroud seals of turbine stages
PublicationThis paper presents experimental investigations which made it possible to determine dynamic coefficients of labyrinth over-shroud seal of a model air turbine. The coefficients associate pressure forces with turbine rotor displacement, velocity and acceleration respective to turbine casing (linear model) and play important role in analyzing turbine-set dynamics. The obtained results indicated that involving serious errors can be...
-
EHV transmission lines wires location on line operation issues - case studies
PublicationTransmission lines towers construction affects the line parameters and influences on its operation in the future. Misguided design of the tower can lead to serious problems such as overvoltages, electric arc extinction difficulties, voltage asymmetry, resonance phenomena or increasing of magnetic field near the line. The paper points out those threats on example of 400 kV double circuit overhead transmission line with shunt reactors....
-
Analysis of the Usefulness of Cheap Audio Recorders for Spectral Measurement of Environmental Noise
PublicationEnvironmental noise pollution is nowadays one of the most serious health threats. The impact of noise on the human body depends not only on the sound level but also on its spectral distribution. Reliable measurements of the environmental noise spectrum are often hampered by the very high price of top quality measuring devices. This paper explores the possibility of using much cheaper audio recorders for the frequency analysis....
-
Challenges in preparing honey samples for chromatographic determination of contaminants and trace residues
PublicationThe determination of contaminations and residues in honey is of growing concern over past few years, especially that these compounds can not only diminish beneficial properties of honey but more importantly, if present in significant amounts, can pose serious threat to human health. Since honey is characterized by complex composition of the matrix sample, it is often necessary to apply clean-up step, in order to eliminate interfering...
-
Improving sensitivity of residual current transformers to high frequency earth fault currents
PublicationFor protection against electric shock in low voltage systems residual current devices are commonly used. However, their proper operation can be interfered when high frequency earth fault current occurs. Serious hazard of electrocution exists then. In order to detect such a current, it is necessary to modify parameters of residual current devices, especially the operating point of their current transformer. The authors proposed...
-
Searching for Critical Conditions During Lifeboat Launching – Simulations
PublicationThe article describes numerical simulations of the process of lifeboat launching at the ship’s side. The research is aimed at finding the values of ship motion parameters which appear to be most dangerous for people in the lowered lifeboat due to the generated accelerations. The simplified model of ship hull motion adopted at this research stage bases on a superposition of harmonic motions with given amplitudes and periods in six...
-
Environmentally friendly polymer-rubber composites obtained from waste tyres: A review
PublicationThe paper is transdisciplinary. The complex overview on changes in policy and approach to waste tyres that leads to both solving environmental problem of post consumer tyres and creating environmentally friendlier novel materials are presented. It is shown that in the world, the amount of polymer wastes increases every year. Most of them are in the form of post-consumer tyres. Recycling and recovery of such tyres is a serious environmental...
-
Determination of Mechanical Properties of P91 Steel by Means of Magnetic Barkhausen Emission
PublicationIn this work, an attempt at determination of mechanical properties by means of a method based on magnetic Barkhausen emission measurements was proposed. The specimens made of P91 steel were subjected to creep or plastic flow which were interrupted after a range of selected time periods in order to achieve specimens with an increasing level of strain. Subsequently, measurements of magnetic Barkhausen emission were carried out, and...
-
Facial data registration facility for biometric protection of electronic documents
PublicationIn modern world, information is crucial, and its leakage may lead to serious losses. Documents as the main medium of information must be therefore highly protected. Nowadays, the most common way of protecting data is using passwords, however it seems inconvenient to type complex passwords, when it is needed many times a day. For that reason a significant research has been conducted on biometric authentication...
-
Reactive Processing and Functionalization of Ground Tire Rubber
PublicationThe dynamic development of the automotive industry resulted in a sig- nificant increase in rubber wastes, especially end-of-life tires, which are a serious threat to the natural environment and human health. This situation has enforced the industry and academic research groups to search new and cost-effective methods for recycling waste tires. In this field of research, reactive processing and functionaliza- tion seem to be a...
-
Speed sensorless induction motor drive with predictive current controller
PublicationToday, speed sensorless modes of operation are becoming standard solutions in the area of electric drives. This paper presents a speed sensorless control system of an induction motor with a predictive current controller. A closed-loop estimation system with robustness against motor parameter variation is used for the control approach. The proposed algorithm has been implemented using field-programmable gate arrays (FPGAs) and a...
-
Surface Dielectric Barrier Discharge Plasma Actuators
PublicationThis paper presents a part of the works conducted in the Plasmaero European project (task 1.1) on surface dielectric barrier discharge actuators applied to airflow control. The study is divided into several parts. In the first part, the goal is to enhance the electric wind produced by a typical single DBD actuator by optimization of the active electrode shape. For instance, the use of a thin wire instead of a plate air-exposed...
-
Call Processing Performance in a Multidomain IMS/NGN with Asymmetric Traffic
PublicationIn this paper we continue our research using the previously proposed analytical traffic model of a multidomain Next Generation Network (NGN), which is standardized for delivering multimedia services based on the IP Multimedia Subsystem (IMS). The aim of the model is to assess mean Call Set-up Delay (CSD) and mean Call Disengagement Delay (CDD), which are standardized call processing performance parameters. The output variables...
-
Linear viscoelastic modelling of damage-involved structural pounding during earthquakes
PublicationDamage-involved structural pounding during earthquakes has been recently intensively studied using different impact force models. The results of the previous studies indicate that the linear viscoelastic model is relatively simple yet accurate in modelling pounding-involved behaviour of structures during earthquakes. The only shortcoming of the model is a negative value of the pounding force occurring just before separation, which...
-
Scheduling for Industrial Control Traffic Using Massive MIMO and Large Intelligent Surfaces
PublicationIndustry 4.0, with its focus on flexibility and customizability, is pushing in the direction of wireless communication in future smart factories, in particular massive multiple-input multiple-output (MIMO), and its future evolution Large Intelligent Surfaces (LIS), which provide more reliable channel quality than previous technologies. As such, there arises the need to perform efficient scheduling of industrial control traffic...
-
Graphical interface adaption for children to explain astronomy proportions and distances
PublicationMobile Science Center is a Polish project that seeks to bring astronomy knowledge to wider social groups through various applications. In its development it is necessary to design a graphical interface that explains a concept that is difficult to assimilate such as spatial proportions and distances. This paper develops a framework to create graphical representations that explain this learning to the target audience of children....
-
Potential energy curves, transition and permanent dipole moments of KRb
PublicationWe present extensive calculations of 48 adiabatic potential energy curves of the KRb molecule. Efforts have been focused on preparing the appropriate basis sets. Compared to previous approaches, the set of new potential energy curves is extended to higher excitations, including the single-excited K(4s2S)+Rb(5d2D) and double-excited K(4p2P)+Rb(5p2P) atomic limits. Larger distances between nuclei are also taken into account. New...
-
Tensor Decomposition for Imagined Speech Discrimination in EEG
PublicationMost of the researches in Electroencephalogram(EEG)-based Brain-Computer Interfaces (BCI) are focused on the use of motor imagery. As an attempt to improve the control of these interfaces, the use of language instead of movement has been recently explored, in the form of imagined speech. This work aims for the discrimination of imagined words in electroencephalogram signals. For this purpose, the analysis of multiple variables...
-
Dissociative Electron Attachment to 5-Iodo-4-thio-2′-deoxyuridine: A Potential Radiosensitizer of Hypoxic Cells
PublicationIn the search for effective radiosensitizers for tumor cells, halogenated uracils have attracted more attention due to their large cross section for dissociation upon the attachment of low-energy electrons. In this study, we investigated dissociative electron attachment (DEA) to 5-iodo-4-thio-2'-deoxyuridine, a potential radiosensitizer using a crossed electron-molecule beam experiment coupled with quadrupole mass spectrometry....
-
Identification of Public Service Logic (PSL) and Public Service Motivation (PSM) elements in Open Government Data (OGD) initiatives
PublicationWhile previous research on Open Government Data (OGD) has primarily focused on reuse and adoption, this study aims to explore the implications of the Public Service Logic (PSL) and Public Service Motivation (PSM) dimensions in the context of OGD initiatives. This study is contextualized in Tanzania wherein the OGD initiatives are at an evolving stage. For the present study, the perspectives of the 15 public officials involved in...
-
New σ-phases in the Nb–X–Ga and Nb–X–Al systems (X = Ru, Rh, Pd, Ir, Pt, and Au)
PublicationPreviously unreported σ-phases in the ternary niobium-based systems Nb–X–Ga for X = Ru, Rh, Pd, Ir, Pt, Au, and Nb–X–Al for X = Ir, and Pt are presented, prepared by arc-melting followed by annealing at 1000 °C for 1 week. The phases are primitive tetragonal (P42/mnm, no. 136) with lattice parameters of a = 9.8336(2)–9.9432(1) Å and c = 5.1098(1)–5.1718(1) Å. Refinements of the single crystal X-ray diffraction data for the Ru and...
-
Synthesis of Combretastatin A-4 Analogs and their Biological Activities
PublicationCombretastatin A-4 (CA-4) is a natural product, which consists of two phenyl rings, linked by an ethylene bridge. CA-4, inhibitor of polymerization of tubulin to microtubules, possesses a strong antitumor and anti-vascular properties both in vitro and in vivo. Previous studies showed that disodium phosphate salt of CA-4, a water-soluble prodrug is well tolerated at therapeutically useful doses. However, it should be noted that...
-
UNDECLARED WORK IN POLAND CHARACTERISTICS AND PREVALENCE
PublicationThis article aims to present the significance and prevalence of the phenomenon of undeclared work. First, we discuss the definitional issues of this phenomenon. Then, we present previous estimates on shadow economy and undeclared work in Poland, based on statistics provided by Central Statistical Office and other research entities. Our analysis covers the years 2000–2014. In the last part of the article, we use data from the Labour...
-
Radioisotope measurement of selected parameters of liquid-gas flow using single detector system
PublicationTo determine the parameters of two-phase flows using radioisotopes, usually two detectors are used. Knowing the distance between them, the velocity of the dispersed phase is calculated based on time delay estimation. Such a measurement system requires the use of two gamma-ray sealed sources. But in some situations it is also possible to determine velocity of dispersed phase using only one scintillation probe and one gamma-ray source....
-
Toward Robust Pedestrian Detection With Data Augmentation
PublicationIn this article, the problem of creating a safe pedestrian detection model that can operate in the real world is tackled. While recent advances have led to significantly improved detection accuracy on various benchmarks, existing deep learning models are vulnerable to invisible to the human eye changes in the input image which raises concerns about its safety. A popular and simple technique for improving robustness is using data...
-
Auto-tuning methodology for configuration and application parameters of hybrid CPU + GPU parallel systems based on expert knowledge
PublicationAuto-tuning of configuration and application param- eters allows to achieve significant performance gains in many contemporary compute-intensive applications. Feasible search spaces of parameters tend to become too big to allow for exhaustive search in the auto-tuning process. Expert knowledge about the utilized computing systems becomes useful to prune the search space and new methodologies are needed in the face of emerging heterogeneous...
-
Propagation of initially sawtooth periodic and impulsive signals in a quasi-isentropic magnetic gas
PublicationThe characteristics of propagation of sawtooth periodic and impulsive signals at a transducer are analytically studied in this work. A plasma under consideration is motionless and uniform at equilibrium, and its perturbations are described by a system of ideal magnetohydrodynamic equations. Some generic heating/cooling function, which in turn depends on equilibrium thermodynamic parameters, may destroy adiabaticity of a flow and...
-
Pounding between high-rise buildings founded on different soil types
PublicationEarthquake-induced pounding is a phenomenon that has been often experienced in previous earthquakes. The aim of this study is to investigate the effect of the soil type on high-rise buildings experiencing earthquake induced-pounding. Pounding between 7-storey and 9-storey buildings is examined under five soil types defined in the ASCE 7-10 code which are hard rock, rock, very dense soil and soft rock, stiff soil and soft clay soil....
-
Determinants of Directionality and Efficiency of the ATP Synthase Fo Motor at Atomic Resolution
PublicationFo subcomplex of ATP synthase is a membrane-embedded rotary motor that converts proton motive force into mechanical energy. Despite a rapid increase in the number of high-resolution structures, the mechanism of tight coupling between proton transport and motion of the rotary c-ring remains elusive. Here, using extensive all-atom free energy simulations, we show how the motor’s directionality naturally arises from the interplay...
-
Adaptive Method for Modeling of Temporal Dependencies between Fields of Vision in Multi-Camera Surveillance Systems
PublicationA method of modeling the time of object transition between given pairs of cameras based on the Gaussian Mixture Model (GMM) is proposed in this article. Temporal dependencies modeling is a part of object re-identification based on the multi-camera experimental framework. The previously utilized Expectation-Maximization (EM) approach, requiring setting the number of mixtures arbitrarily as an input parameter, was extended with the...
-
Towards Use of OntoClean for Ontology Contextualization
PublicationOntologies are formal systems of concepts used to describe numerous domains of interest. Ontologies are usually very expressive, but it comes at a price of computationally expensive reasoning over them. In our previous work we discussed the possible performance benefits that can be obtained by decomposing an ontology into contexts. While the benefits are appealing, we discovered that, in our case, the main obstacle against using...
-
Computational analysis of an infinite magneto-thermoelastic solid periodically dispersed with varying heat flow based on non-local Moore–Gibson–Thompson approach
PublicationIn this investigation, a computational analysis is conducted to study a magneto-thermoelastic problem for an isotropic perfectly conducting half-space medium. The medium is subjected to a periodic heat flow in the presence of a continuous longitude magnetic field. Based on Moore–Gibson–Thompson equation, a new generalized model has been investigated to address the considered problem. The introduced model can be formulated by combining...
-
Diagnostyka ultradźwiękowa mostowej belki prefabrykowanej typu T metodą młoteczkową
PublicationZastosowanie prefabrykacji w budowie obiektów mostowych pozwala optymalizować zużycie energii i materiałów i tym samym redukować koszty budowanego obiektu. Prefabrykowane belki sprężone mogą występować jako elementy kablobetonowe wykonywane bezpośrednio na placu budowy lub powstawać w zakładzie prefabrykacji jako elementy strunobetonowe. Elementy prefabrykowane wytwarzane w warunkach przemysłowych muszą spełniać wymagania wysokiej trwałości,...
-
Instalacja oświetleniowa w zbiorniku wody "Stary Sobieski" - rozważania o spektakularnym zabytku techniki
PublicationArtykuł przedstawia efekty badań autora nad niezwykle okazałą, ponad stuletnią instalacją elektryczną, która zachowała się w zabytkowym obiekcie infrastruktury wodociągowej w niemal 100% oryginalnej formie (nie licząc częściowej dewastacji). Jest to rzadki przykład tego rodzaju zabytku, ponieważ obiekty tego typu i w tym wieku zwykle podlegały modernizacji na przestrzeni lat albo, po wyłączeniu z eksploatacji zostały całkowicie...
-
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...
-
Pomiędzy kontrolą i zaufaniem – jakich liderów potrzebują wirtualne zespoły projektowe
PublicationArtykuł dotyczy zarządzania zespołem wirtualnym, które jest szczególnym wyzwaniem ze względu na rozproszenie geograficzne członków zespołu oraz porozumiewanie się za pośrednictwem technologii informacyjnej. Skoncentrowano się na utrzymywaniu odpowiedniej proporcji pomiędzy zaufaniem i kontrolą zespołu i opracowano listę rekomendacji dla liderów zespołów wirtualnych, dotyczących budowania zaufania i koordynacji pracy. Do realizacji...
-
Cerebral oedema - Male, 0 - Tissue image [405073001068981]
Open Research DataThis is the histopathological image of BRAIN tissue sample obtained in Medical University Gdańsk and deposited in ZMDL-GUMED. The sample image was taken using: Pannoramic 250 3DHistech slide scanner (20x magnification) and saved to DICOM format.