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Mixed 4-node shell element with assumed strain and stress in 6-parameter theory
- Jacek Chróścielewski
- Stanisław Burzyński
- Karol Daszkiewicz
- Wojciech Witkowski
We propose a mixed hybrid 4-node shell elements based on Hu-Washizu principle. Apart from displacements both strains and stress fields are treated as independent fields. The element is derived in the framework of a general nonlinear 6-field shell theory with drilling rotation which is dedicated to the analysis of multifold irregular shells with intersections. The novelty of the presented results stems from the fact that the measures of strains and resultant stresses are asymmetric. With the proposed mixed 4-node element it is possible to use large load steps in nonlinear computations.
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Mixed ionic-electronic conductivity and structural properties of strontium-borate glass containing nanocrystallites of Bi2 VO5.5
- Natalia Anna Wójcik
- Marta Prześniak-Welenc
- Piotr Kupracz
- Jakub Karczewski
- Maria Gazda
- Ryszard Jan Barczyński
Samples of strontium borate glass containing bismuth vanadate nanocrystallites were prepared. Nanocomposites containing up to 45mol% of the Bi2VO5.5 phase exhibit electrical properties closer to the strontium-borate glass than to the ferroelectric Bi2VO5.5 ceramic. The glass matrix still may contain some part of bismuth and vanadium ions even after crystallization process and there is too little of crystalline phase to observe its ferroelectric properties. The glass-ceramic nanocomposite containing 50mol% of Bi2VO5.5 phase exhibits electrical properties closer to the Bi2VO5.5 ferroelectric. The electric parameters of conduction processes in the Bi2VO5.5 nanocrystallites, glass matrix and phases boundaries are discussed. The conduction process mechanism in all nanocomposites for the low temperatures is mixed ionic–electronic and in the higher temperatures the oxygen ion hopping starts to dominate.
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Mobile devices and computing cloud resources allocation for interactive applications
- Henryk Krawczyk
- Michał Nykiel
Using mobile devices such as smartphones or iPads for various interactive applications is currently very common. In the case of complex applications, e.g. chess games, the capabilities of these devices are insufficient to run the application in real time. One of the solutions is to use cloud computing. However, there is an optimization problem of mobile device and cloud resources allocation. An iterative heuristic algorithm for application distribution is proposed. The algorithm minimizes the energy cost of application execution with constrained execution time.
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Mobility Oriented Development (MOD): Public-Private Partnership in Urban Parking & Traffic Management with the Use of Autonomous Automobiles, Car-Sharing, Ridesharing Modes of Transport & Mobility as a Service (MaaS)
- Piotr Marek Smolnicki
The focus of the following research are relations between mobility technologies and metropolitan (urban and suburban) spatial structures. In this paper the author discusses various urban modes of transport (automobile, mass transit) in the context of emerging technical (autonomous vehicles, self-driving cars and driverless shuttles) and organizational (carpooling, ridesharing, car-sharing, on-demand mobility) solutions for " mobility as a service ". The author presents assumptions (chances and threats) and proposes solutions for an optimal scenario for better city management and development.
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Modal Analysis of a Steel Radial Gate Exposed to Different Water Levels
- Krzysztof Brusewicz
- Witold Sterpejkowicz-Wersocki
- Robert Jankowski
With the increase in water retention needs and planned river regulation, it might be important to investigate the dynamic resistance of vulnerable elements of hydroelectric power plants, including steel water locks. The most frequent dynamic loads affecting hydroengineering structures in Poland include vibrations caused by heavy road and railway traffic, piling works and mining tremors. More destructive dynamic loads, including earthquakes, may also occur in our country, although their incidence is relatively low. However, given the unpredictable nature of such events, as well as serious consequences they might cause, the study of the seismic resistance of the steel water gate, as one of the most vulnerable elements of a hydroelectric power plant, seems to be important. In this study, a steel radial gate has been analyzed. As far as water gates are concerned, it is among the most popular solutions because of its relatively small weight, compared to plain gates. A modal analysis of the steel radial gate was conducted with the use of the FEM in the ABAQUS software. All structural members were modelled using shell elements with detailed geometry representing a real structure. Water was modelled as an added mass affecting the structure. Different water levels were used to determine the most vulnerable state of the working steel water gate. The results of the modal analysis allowed us to compare the frequencies and their eigenmodes in response to different loads, which is one of the first steps in researching the dynamic properties of steel water gates and their behaviour during extreme dynamic loads, including earthquakes.
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MODEL FOR MEASUREMENT OF FLOW INSTALLATION TIME IN SDN SWITCH
- Sylwester Kaczmarek
- Jacek Andrzej Litka
SDN is the approach in telecommunication networks that separates control plane from data forwarding plane by specifying a single network entity as a controller that defines rules (called flows) of traffic forwarding for the switches connected to it. The time that is required for installation of these rules might be a hindrance for the overall performance of SDN network. In the paper, a model for testing and evaluating the influence of traffic payload on flow installation time is presented as well as an implementation of the early experiments’ results are provided.
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Modele biomechaniczne układów mięśniowo-szkieletowych
- Wiktoria Wojnicz
Zakres niniejszej pracy obejmuje: 1) przedstawienie podstawowych cech fizjologicznych będących podstawą do zamodelowania zachowania pojedynczego mięśnia szkieletowego (biomechanika mięśnia szkieletowego) oraz zespołu mięśni (biomechanika zespołu mięśni szkieletowych); 2) zaprezentowanie sposobu modelowania zachowania mięśnia szkieletowego obłego (wrzecionowatego) i pierzastego oraz układu mięśni jednostawowych i dwustawowych; 3) sformułowanie podejścia do projektowania urządzenia do rehabilitacji kończyny górnej.
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Modele budowy wartości dla klienta - charakterystyka i rozwinięcie
- Tadeusz Falencikowski
Rozwój form realizacji biznesu umożliwił zbadanie nowych obiektów związanych z generowaniem wartości dla klienta i przedsiębiorstwa. W pracy scharakteryzowano logiki tworzenia wartości będące podstawą modeli łańcucha wartości, sklepu wartości, sieci wartości oraz chmury wartości. Zaproponowano także wprowadzenie nowego składnika do struktury tych modeli w postaci węzła wartości.
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Modele numeryczne uwzględniające tarczową pracę pokrycia dachowego z blach trapezowych
- Natalia Korcz-Konkol
W artykule porównano wybrane sposoby uwzględniania w modelowaniu numerycznym tarczowej pracy pokrycia dachowego z blachy trapezowej, możliwe do zrealizowania w programie Autodesk Robot Structural Analysis Professional 2015, w celu oceny słuszności stosowania ich do obliczeń konstrukcji nośnej współpracującej z poszyciem z blachy trapezowej. Analizy przeprowadzono dla pojedynczej przepony. Za pomocą powłokowych elementów skończonych zbudowano dwa typy modeli blachy trapezowej. Uwzględniono podatność połączeń występujących w konstrukcji, wykorzystując pomocnicze belkowe elementy skończone. Wartości podatności na ścinanie paneli uzyskane numerycznie odniesiono do wyników otrzymanych na podstawie znanych procedur analitycznych. Miarą trafności modelu poszycia był poziom zgodności ww. wartości podatności na ścinanie. Zgodnie z tym kryterium wskazano model, który poprawniej odzwierciedla współpracę pokrycia z blachy trapezowej z konstrukcją nośną.
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Modele relacji między Corporate Social Responsibility a public relations
- Ewa Hope
Artykuł jest próbą usystematyzowania dotychczasowych rozstrzygnięć dotyczących relacji między CSR [Corporate Social Responsibility] i public relations - występujących tak w literaturze przedmiotu jak i w praktyce organizacji. Autorka prezentuje też własną koncepcję, proponując trzy modele, które opisują i wyjaśniają nie tylko wzajemne relacje między CSR i PR, ale też i wyjaśniają funkcje, jakie nadaje się w organizacjach działaniom społecznie odpowiedzialnym i strategiom zarządzania komunikacją. Modele ilustrują też poziom rozwoju, dojrzałości organizacji i usytuowanie jej w szerokim otoczeniu – społecznym i przyrodniczym.
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Modeling a Traffic Remapping Attack Game in a Multi-hop Ad Hoc Network
- Jerzy Konorski
- Szymon Szott
In multi-hop ad hoc networks, selfish nodes may unduly acquire high quality of service (QoS) by assigning higher priority to source packets and lower priority to transit packets. Such traffic remapping attacks (TRAs) are cheap to launch, impossible to prevent, hard to detect, and harmful to non-selfish nodes. While studied mostly in single-hop wireless network settings, TRAs have resisted analysis in multi-hop settings. In this paper we offer a game-theoretic approach: we derive a formal model of opportunistic TRAs, define a TRA game with a heuristic rank-based payoff function, and propose a boundedly rational multistage attack strategy that both selfish and non-selfish nodes are free to use. Thus non-selfish nodes are allowed to respond in kind to selfish ones. We characterize the form of equilibrium that the multistage play reaches and verify via simulation that it often coincides with a Nash equilibrium in which harmful TRAs are curbed in the first place, whereas harmless ones need not be.
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Modeling and Simulation for Exploring Power/Time Trade-off of Parallel Deep Neural Network Training
- Paweł Rościszewski
In the paper we tackle bi-objective execution time and power consumption optimization problem concerning execution of parallel applications. We propose using a discrete-event simulation environment for exploring this power/time trade-off in the form of a Pareto front. The solution is verified by a case study based on a real deep neural network training application for automatic speech recognition. A simulation lasting over 2 hours on a single CPU accurately predicts real results from executions that take over 335 hours in a cluster with 8 GPUs. The simulations allow also estimating the impact of data package imbalance on the application performance.
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Modeling of Cardiac Component of Subarachnoid Space Changes in Apnoea Resulting as a Function of Blood Pressure and Blood Flow Parameters - Two Mechanizm of Regulation
- Kamila Mazur
- Renata Kalicka
- Andrzej F. Frydrychowski
- Paweł J. Winklewski
Experiments were performed in a group of 19 healthy, non-smoking volunteers. The experiment consisted of three apnoeas, sequentially: 30 s apnoea, 60 s apnoea and maximal, that could be done, apnoea. The breath-hold was separated for 5 minutes rest. The following parameters were measured and obtained for further analysis: blood parameters, artery diameter of the internal carotid artery, end-tidal CO2 in expired air, the cardiac (from 0.5 to 5.0 Hz) and slow (< 0.5 Hz) components of subarachnoid space width signal. As a result of the experiment, we observed two different reactions, using the same experimental procedure. It seemed to indicate two different operating modes and two separate models. As a consequence, there are two subsets of slow subarachnoid space width responses to breath-hold in humans. A positive subarachnoid space width changes (slow) component depends on changes in heart rate, pulsatility index and cerebral blood flow velocity. A negative subarachnoid space width cha nges component is driven by heart rate changes and pulsatility index changes. The different heart-generated arterial pulsation response to experimental breath-hold provides new insights into our understanding of the complex mechanisms governing the adaptation to apnoea in humans. We propose a mathematical methodology that can be used in further clinical research.
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Modeling of lapping plate wear and conditioning in single-sided lapping
- Adam Barylski
- Norbert Piotrowski
In order to achieve higher quality on worked surfaces with lower roughness, very high accuracy of shape and dimensions it is crucial to improve conventional finishing technologies and to develop new working principles. Single-sided lapping is one of the most effective planarization technologies and it is determined by a number of factors and boundary conditions. The most significant influence over a dimensional and profile accuracy, as well as over a surface quality of a workpiece has the lapping plate. Moreover, it could be established that workpieces are machined to a mirror image of the tool with respect to the flatness. Since, the wear of the lapping plate is not constant over the diameter, it does not remain flat and causes the following shape errors: convexity, concavity and axial runout. Hence, it is crucial to maintain proper conditions of process, control the flatness and condition the tool, when it is necessary. This paper presents a comprehensive study of the materials removal mechanisms in abrasives process. The model of lapping plate wear in single-sided lapping were created and in detail analyzed. Matlab program was designed to simulate the abrasive particles trajectories and to count their distribution. It was observed, that a trajectories distribution of abrasive particles on the lapping plate varies when the running parameters and kinematics of conditioning ring movements are changed. Recommended kinematic parameter settings of single-sided lapping process were presented. Finally, the results of the simulation were compared with the results of experimental research.
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Modeling of light propagation in canine gingiva
- Marcin Mrotek
This study is a preliminary evaluation of the effectivenes of laser-based surgery of maxillary and mandibular bone in dogs. Current methods of gingivial surgery in dogs require the use of general anaesthesia.1, 2 The proposed methods of laser surgery can be performed on conscious dogs, which substantially reduces the associated risks. Two choices of lasers, Nd:YAG and a 930 nm semiconductor lasers were evaluated. The former is already widely used in human laser surgery, while the latter provides an opportunity of decreasing the size of the optical setup. The results obtained from the simulations warrant further experiments with the evaluated wavelengths and animal tissue samples.
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Modeling of luminance distribution in CAVE-type virtual reality systems
- Michał Meironke
- Adam Mazikowski
At present, one of the most advanced virtual reality systems are CAVE-type (Cave Automatic Virtual Environment) installations. Such systems are usually consisted of four, five or six projection screens and in case of six screens arranged in form of a cube. Providing the user with a high level of immersion feeling in such systems is largely dependent of optical properties of the system. The modeling of physical phenomena plays nowadays a huge role in the most fields of science and technology. It allows to simulate work of device without a need to make any changes in the physical constructions. In this paper distribution of luminance in CAVE-type virtual reality systems were modelled. Calculations were performed for the model of 6-walled CAVE-type installation, based on Immersive 3D Visualization Laboratory, situated at the Faculty of Electronics, Telecommunications and Informatics at the Gdansk University of Technology. Tests have been carried out for two different scattering distribution of the screen material in order to check how these characteristicinfluence on the luminance distribution of the whole CAVE. The basis assumption and simplification of modeled CAVE-type installation and results were presented. The brief discussion about the results and usefulness of developed model were also carried out.