2017 - Repozytorium publikacji - Politechnika Gdańska

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Partnerstwo publiczno-prywatne jako instrument wsparcia innowacji
- Anna Lis
- Ewa Romanowska
2017 Pełny tekst PRZEGLĄD ORGANIZACJI
Przedmiotem rozważań niniejszego artykułu jest koncepcja partnerstwa publiczno-prywatnego jako instrumentu wspierającego rozwój innowacji. Analizie poddano niemiecki model funkcjonowania PPP, w tym przede wszystkim inicjatywę na rzecz badań i innowacji – Forschungscampus. Zasadniczą część pracy poprzedza przegląd dorobku teoretycznego w zakresie współpracy sfery publicznej i prywatnej, w tym jej atrybutów, komponentów oraz faz rozwoju.
Patch size setup and performance/cost trade-offs in multi-objective EM-driven antenna optimization using sequential domain patching
- Sławomir Kozieł
- Adrian Bekasiewicz
2017 ENGINEERING COMPUTATIONS
Purpose This paper aims to assess control parameter setup and its effect on computational cost and performance of deterministic procedures for multi-objective design optimization of expensive simulation models of antenna structures. Design/methodology/approach A deterministic algorithm for cost-efficient multi-objective optimization of antenna structures has been assessed. The algorithm constructs a patch connecting extreme Pareto-optimal designs (obtained by means of separate single-objective optimization runs). Its performance (both cost- and quality-wise) depends on the dimensions of the so-called patch, an elementary region being relocated in the course of the optimization process. The cost/performance trade-offs are studied using two examples of ultra-wideband antenna structures and the optimization results are compared to draw conclusions concerning the algorithm robustness and determine the most advantageous control parameter setups. Findings The obtained results indicate that the investigated algorithm is very robust, i.e. its performance is weakly dependent on the control parameters setup. At the same time, it is found that the most suitable setups are those that ensure low computational cost, specifically non-uniform ones generated on the basis of sensitivity analysis. Research limitations/implications The study provides recommendations for control parameter setup of deterministic multi-objective optimization procedure for computationally efficient design of antenna structures. This is the first study of this kind for this particular design procedure, which confirms its robustness and determines the most suitable arrangement of the control parameters. Consequently, the presented results permit full automation of the surrogate-assisted multi-objective antenna optimization process while ensuring its lowest possible computational cost. Originality/value The work is the first comprehensive validation of the sequential domain patching algorithm under various scenarios of its control parameter setup. The considered design procedure along with the recommended parameter arrangement is a robust and computationally efficient tool for fully automated multi-objective optimization of expensive simulation models of contemporary antenna structures.
Path planning algorithm for ship collisions avoidance in environment with changing strategy of dynamic obstacles
- Łukasz Kuczkowski
- Roman Śmierzchalski
2017 Advances in Intelligent Systems and Computing
In this paper a path planning algorithm for the ship collision avoidance is presented. Tested algorithm is used to determine close to optimal ship paths taking into account changing strategy of dynamic obstacles. For this purpose a path planning problem is defined. A specific structure of the individual path and fitness function is presented. Principle of operation of evolutionary algorithm and based on it dedicated application vEP/N++ is described. Using presented algorithm the simulations on close-to-real sea environment is performed. Tested environment presents the problem of avoiding one static obstacle representing island and two dynamic objects representing strange ships.Obtained results proof that used approach allows to calculate efficient and close-to-optimal path for marine vessel in close-to-real time.
Path-based methods on categorical structures for conceptual representation of wikipedia articles
- Łukasz Kucharczyk
- Julian Szymański
2017 Pełny tekst JOURNAL OF INTELLIGENT INFORMATION SYSTEMS
Machine learning algorithms applied to text categorization mostly employ the Bag of Words (BoW) representation to describe the content of the documents. This method has been successfully used in many applications, but it is known to have several limitations. One way of improving text representation is usage of Wikipedia as the lexical knowledge base – an approach that has already shown promising results in many research studies. In this paper we propose three path-based measures for computing document relatedness in the conceptual space formed by the hierarchical organization of a Wikipedia Category Graph (WCG). We compare the proposed approaches with the standard Path Length method to establish the best relatedness measure for the WCG representation. To test overall WCG efficiency, we compare the proposed representations with the BoW method. The evaluation was performed with two different types of clustering algorithms (OPTICS and K-Means), used for categorization of keyword-based search results. The experiments have shown that our approach outperforms the standard Path Length approach, and the WCG representation achieves better results than BoW.
Pavement ageing influence on tyre/road noise
- Piotr Mioduszewski
- Karol Kowalski
2017
Road surface should be constructed in a way that ensures safe and comfortable traffic conditions, not only when it is newly paved but also during its entire lifetime. An important factor in the asphalt mixture design process is also the expected pavement durability and stability of pavement properties over time. In many countries, road surface starts to play a significant role in traffic noise reduction actions. Selecting a particular mixture type for pavement, its mechanical and acoustical durability should be properly balanced. Road surface ageing is a widely studied phenomena from the mechanical point of view (cracking, rutting, etc.), however change of its noise characteristics over time is less investigated. The pavement ageing influence on tyre/road noise presented in this paper was derived based on numerous CPX measurements performed on 26 road sections located in Europe. Detailed analysis taking into account the overall CPXI values, as well as separate indexes calculated for passenger cars and heavy trucks, was conducted for six different types of bituminous wearing courses with maximum aggregate size of 8, 11 and 16 mm. Pavements were listed in two groups: normal noise (dense asphalt concrete, stone mastic asphalt, thin asphalt layer) and reduced noise (porous asphalt concrete, double layer porous asphalt concrete, asphalt rubber). For the vast majority of sections the noise measurements were made several times over a period of a few years, usually starting one month after pavement construction. Concluding, for dense road surfaces the noise emission increases by 1-2 dB over the first 1-2 years and then stabilizes, sometimes slightly decreases. For double layer porous asphalts a moderate increase was noted, 0.5 dB/year on average. Asphalt rubber pavements were characterized by continuous and stable increase in noise, about 1 dB per year. The obtained results confirm available literature data with an exception for single layer porous asphalts, for which the ageing effect was found to be negligible.
Pedestrian and bicycle bridges as examples of safe collision-free road crossings
- Mikołaj Miśkiewicz
- Łukasz Pyrzowski
- Romanika Okraszewska
2017 Pełny tekst MATEC Web of Conferences
Pedestrians are most at risk when they are crossing the road. This represents a significant proportion of all fatalities among pedestrians, amounting respectively to 50% in non-built-up areas and 75% in built-up areas. The most frequent reason for this accident is failure to give way. What is most terrible is that 30% of pedestrian accidents occurred at marked pedestrian crossings. Therefore, an important part of pedestrian safety management is selecting the right type of crossings, which are suitable for the conditions. At certain speeds and traffic volume, the only safe option for pedestrian crossings is to apply multi-level solutions, that is footbridges or tunnels. The paper presents examples of infrastructure redesign by constructing footbridges and hence, separating pedestrians and vehicular traffic to improve pedestrian safety.
Pedestrian safety in road traffic – studies, recommendations and proposed improvements
- Marcin Budzyński
- Lucyna Gumińska
- Łukasz Jeliński
- Mariusz Kieć
2017 Pełny tekst MATEC Web of Conferences
Pedestrians are involved and most frequently the victims of every third road accident in Poland. Pedestrian accidents most frequently occur in complex circumstances, as a result of many factors related to the behaviour of drivers and pedestrians. The basic parameters that determine road safety include the perception of traffic and visibility on the road. The paper will present the results of research conducted within the project commissioned by the National Road Safety Council Secretariat titled “The methodology of systematic study on pedestrian behaviour and pedestrian - car driver relations”. The authors will present the impact of location, type of cross-section and other selected parameters on the behaviour of drivers and pedestrians in the area of pedestrian crossings. The paper will also present recommendations for the design of pedestrian crossings and monitoring road user behaviour at pedestrian crossings.
Pedestrian Safety in Road Traffic in Poland
- Marcin Budzyński
- Kazimierz Jamroz
- Tomasz Mackun
2017 Pełny tekst IOP Conference Series: Materials Science and Engineering
Every third road accident in Poland involves a pedestrian as a participant or, most of the time, a casualty. Pedestrian accidents are usually the result of complex situations and the outcome of a number of factors related to driver and pedestrian behaviour and road infrastructure. Safety depends largely on how well the traffic condition is perceived and on visibility in traffic. The paper presents the results of analyses of methodologies for systematic studies of pedestrian behaviour and pedestrian-driver relations. The effects of the location of the site, type of cross-section and other selected parameters on pedestrian and driver behaviour are demonstrated. The analyses showed that pedestrians are most often put at risk by too long pedestrian crossings, vehicles going too fast around pedestrian crossings, lack of proper sight distance and poorly lit or unlit pedestrian crossings. The reason for such defective infrastructure is that planners, designers, contractors and maintenance services are not receiving any support from design, marking and maintenance regulations for pedestrian traffic. In addition, the Road Traffic Law is not restrictive enough when it comes to drivers' obligations towards pedestrian safety. Polish design regulations allow long pedestrian crossings up to four lanes in one direction or three lanes in two directions irrespective of traffic control and speed limits. Pedestrian crossings should be kept at a maximum of three lanes. There is nothing in the design regulations about the required driver-pedestrian sight distance. Neither does the Road Traffic Law help engineers with that. It is legal to park vehicles within 10 m of a pedestrian crossing which does not guarantee the necessary sight distance. Drivers must be able to see a pedestrian waiting or stepping onto the crossing from a distance that will help them come to a stop safely. It is safer to follow the principle of providing adequate pedestrian sight distance. Recommendations for pedestrian crossing design are also provided.
Pedestrian safety management using the risk-based approach
- Aleksandra Romanowska
- Kazimierz Jamroz
- Wojciech Kustra
2017 Pełny tekst MATEC Web of Conferences
The paper presents a concept of a multi-level pedestrian safety management system. Three management levels are distinguished: strategic, tactical and operational. The basis for the proposed approach to pedestrian safety management is a risk-based method. In the approach the elements of behavioural and systemic theories were used, allowing for the development of a formalised and repeatable procedure integrating the phases of risk assessment and response to the hazards of road crashes involving pedestrians. Key to the method are tools supporting pedestrian safety management. According to the risk management approach, the tools can be divided into two groups: tools supporting risk assessment and tools supporting risk response. In the paper attention is paid to selected tools supporting risk assessment, with particular emphasis on the methods for estimating forecasted pedestrian safety measures (at strategic, national and regional level) and identification of particularly dangerous locations in terms of pedestrian safety at tactical (regional and local) and operational level. The proposed pedestrian safety management methods and tools can support road administration in making rational decisions in terms of road safety, safety of road infrastructure, crash elimination measures or reducing the consequences suffered by road users (particularly pedestrians) as a result of road crashes.
Performance and Stability in H2S of SrFe0.75Mo0.25O3-δ as Electrode in Proton Ceramic Fuel Cells
- Sebastian Lech Wachowski
- Zuoan Li
- Jonathan Polfus
- Truls Norby
2017 Pełny tekst JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
The H2S-tolerance of SrFe0.75Mo0.25O3-δ (SFM) electrodes has been investigated in symmetric proton ceramic fuel cells (PCFC) with BaZr0.8Ce0.1Y0.1O3-δ (BZCY81) electrolyte. The ionic conductivity of the electrolyte under wet reducing conditions was found to be insignificantly affected in the presence of up to 5000 ppm H2S. The fuel cell exhibited an OCV of about 0.9 V at 700 °C, which dropped to about 0.6 V and 0.4 V upon exposure to 500 and 5000 ppm H2S, respectively, on the fuel side. Post characterization of the fuel cell revealed significant degradation of the anode in terms of microstructure and chemical composition due to formation of sulfides such as SrS, MoS2 and Fe3S4. Nevertheless, the fuel cell was still functional due to the sufficient electronic conductivity of some of these sulfides.
Performance Evaluation of Selected Parallel Object Detection and Tracking Algorithms on an Embedded GPU Platform
- Grzegorz Szwoch
- Maciej Szczodrak
2017
Performance evaluation of selected complex video processing algorithms, implemented on a parallel, embedded GPU platform Tegra X1, is presented. Three algorithms were chosen for evaluation: a GMM-based object detection algorithm, a particle filter tracking algorithm and an optical flow based algorithm devoted to people counting in a crowd flow. The choice of these algorithms was based on their computational complexity and parallel structure. The aim of the experiments was to assess whether the current generation of low-power, mobile GPUs has sufficient power for running live analysis of video surveillance streams, e.g. in smart cameras, while maintaining energy consumption at a reasonable level. Tests were performed with both a synthetic benchmark and a real video surveillance recording. It was found that the computational power of the tested platform is sufficient for running operations such as background subtraction, but in case of more complex algorithms, such as tracking with particle filters, performance is not satisfactory because of inefficient memory architecture which stalls the processing.
Performance evaluation of unified memory and dynamic parallelism for selected parallel CUDA applications
- Łukasz Jarząbek
- Paweł Czarnul
2017 Pełny tekst JOURNAL OF SUPERCOMPUTING
The aim of this paper is to evaluate performance of new CUDA mechanisms—unified memory and dynamic parallelism for real parallel applications compared to standard CUDA API versions. In order to gain insight into performance of these mechanisms, we decided to implement three applications with control and data flow typical of SPMD, geometric SPMD and divide-and-conquer schemes, which were then used for tests and experiments. Specifically, tested applications include verification of Goldbach’s conjecture, 2D heat transfer simulation and adaptive numerical integration. We experimented with various ways of how dynamic parallelism can be deployed into an existing implementation and be optimized further. Subsequently, we compared the best dynamic parallelism and unified memory versions to respective standard API counterparts. It was shown that usage of dynamic parallelism resulted in improvement in performance for heat simulation, better than static but worse than an iterative version for numerical integration and finally worse results for Golbach’s conjecture verification. In most cases, unified memory results in decrease in performance. On the other hand, both mechanisms can contribute to simpler and more readable codes. For dynamic parallelism, it applies to algorithms in which it can be naturally applied. Unified memory generally makes it easier for a programmer to enter the CUDA programming paradigm as it resembles the traditional memory allocation/usage pattern.
Performance of a single layer fuel cell based on a mixed proton-electron conducting composite
- Krzysztof Zagórski
- Sebastian Lech Wachowski
- Dagmara Grudzień
- Aleksandra Dorota Mielewczyk-Gryń
- Piotr Jasiński
- Maria Gazda
2017 Pełny tekst JOURNAL OF POWER SOURCES
Many of the challenges in solid oxide fuel cell technology stem from chemical and mechanical incompatibilities between the anode, cathode and electrolyte materials. Numerous attempts have been made to identify compatible materials. Here, these challenges are circumvented by the introduction of a working single layer fuel cell, fabricated from a composite of proton conducting BaCe0.6Zr0.2Y0.2O3-δ and a mixture of semiconducting oxides – Li2O, NiO, and ZnO. Structural and electrical properties of the composite, related to its fuel cell performance are investigated. The single layer fuel cell shows a maximum OCV of 0.83 V and a peak power density of 3.86 mW cm−2 at 600 °C. Activation and mass transport losses are identified as the major limiting factor for efficiency and power output.
Performance of extended Lagrangian schemes for molecular dynamics simulations with classical polarizable force fields and density functional theory
- Valerio Vitale
- Jacek Dziedzic
- Alex Albaugh
- Anders Niklasson
- Teresa Head-Gordon
- Chris-Kriton Skylaris
2017 Pełny tekst JOURNAL OF CHEMICAL PHYSICS
Iterative energy minimization with the aim of achieving self-consistency is a common feature of Born-Oppenheimer molecular dynamics (BOMD) and classical molecular dynamics with polarizable force fields. In the former, the electronic degrees of freedom are optimized, while the latter often involves an iterative determination of induced point dipoles. The computational effort of the self-consistency procedure can be reduced by re-using converged solutions from previous time steps. However, this must be done carefully, as not to break time-reversal symmetry, which negatively impacts energy conservation. Self-consistent schemes based on the extended Lagrangian formalism, where the initial guesses for the optimized quantities are treated as auxiliary degrees of freedom, constitute one elegant solution. We report on the performance of two integration schemes with the same underlying extended Lagrangian structure, which we both employ in two radically distinct regimes—in classical molecular dynamics simulations with the AMOEBA polarizable force field and in BOMD simulations with the Onetep linear-scaling density functional theory (LS-DFT) approach. Both integration schemes are found to offer significant improvements over the standard (unpropagated) molecular dynamics formulation in both the classical and LS-DFT regimes.
Performance of the AMOEBA Water Model in the Vicinity of QM Solutes: A Diagnosis Using Energy Decomposition Analysis
- Yuezhi Mao
- Yihan Shao
- Jacek Dziedzic
- Chris-Kriton Skylaris
- Teresa Head-Gordon
- Martin Head-Gordon
2017 Journal of Chemical Theory and Computation
The importance of incorporating solvent polarization effects into the modeling of solvation processes has been well-recognized, and therefore a new generation of hybrid quantum mechanics/molecular mechanics (QM/MM) approaches that accounts for this effect is desirable. We present a fully self-consistent, mutually polarizable QM/MM scheme using the AMOEBA force field, in which the total energy of the system is variationally minimized with respect to both the QM electronic density and the MM induced dipoles. This QM/AMOEBA model is implemented through the Q-Chem/LibEFP code interface and then applied to the evaluation of solute-solvent interaction energies for various systems ranging from the smallest water dimer to neutral and ionic solutes (NH3-, NH4+, CN-) surrounded by increasing numbers (up to 100) of water molecules. In order to analyze the obtained interaction energies, we also utilize an energy decomposition analysis (EDA) scheme which identifies contributions from permanent electrostatics, polarization and van der Waals (vdW) interaction for the interaction between the QM solute and the solvent molecules described by AMOEBA. This facilitates a component-wise comparison against the full QM references where the corresponding energy components are obtained via a modified version of the absolutely localized molecular orbitals (ALMO)-EDA. The results show that the present QM/AMOEBA model can yield reasonable solute-solvent interaction energies for neutral and cationic species, which, however, highly relies on the delicate balance between insufficiently favorable permanent electrostatics and softened vdW interaction. For anionic solutes where the charge penetration effect becomes more pronounced, the QM/MM interface turns out to be unbalanced. These results are consistent with and further elucidate our findings in a previous study using a slightly different QM/AMOEBA model (J. Chem. Phys. 145, 124106 (2016)), and the implications on future improvement of this model are also discussed.
Performance of the PEM fuel cell module. Part 2. Effect of excess ratio and stack temperature
- Janusz Cieśliński
- Tomasz Kaczmarczyk
- Bartosz Dawidowicz
2017 Pełny tekst Journal of Power Technologies
The paper describes a fuel cell based system performance under different thermal conditions. The system could be fed with bottled hydrogen or with very high purity hydrogen obtained from reforming of methanol. The system is based on two fuel cell units (1.2 kW each, produced by Ballard Power Systems Inc. and called Nexa), DC/DC converter, DC/AC inverter, microprocessor control unit, load unit, bottled hydrogen supply system and a set of measurement instruments. In this study steady-state operation of the PEM fuel cell system at different values of air excess ratio and different stack temperature was investigated. The load of the system was provided with the aid of a set of resistors. The results obtained show that the net power of the system does not depend on the air excess ratio within the range of from1.9 to 5.0. The polarizationcurves of the fuel cell module showed that the fuel cell performance was improved with increased stack temperature within the range of 30◦C to 65◦C. It was established that the total efﬁciency of the tested system depends on the hydrogen source and is higher when using bottled hydrogen of about 30% and 16%, for minimum and maximum load, respectively.
Performance properties of rigid polyurethane-polyisocyanurate/brewers’ spent grain foamed composites as function of isocyanate index
- Aleksander Hejna
- Józef Haponiuk
- Łukasz Piszczyk
- Marek Klein
- Krzysztof Formela
2017 Pełny tekst E-POLYMERS
In the presented work, rigid polyurethane-polyisocyanurate (PUR-PIR) foams filled with brewers’ spent grain (BSG) were prepared. The influence of the isocyanate index (II) on its performance was investigated. Foams obtained with higher isocyanate index required a higher amount of hydrofluorocarbon physical blowing agent to provide the same apparent density of material. An increase of isocyanate index resulted in a slight decrease of cell size, which was related to the increased crosslink density due to enhanced generation of allophanate and biuret groups. Deterioration of compressive strength, from 226 to 202 kPa was observed with the rise of the isocyanate index. Dynamic mechanical analysis and swelling tests confirmed the increase of crosslink density with the increasing isocyanate index. The glass transition temperature rose from 165.7°C to 193.2°C. Fourier transform infrared (FTIR) analysis indicated an increase of the isocyanurate rings’ content in composites with a higher isocyanate index, causing noticeable enhancement of thermal stability. The onset of degradation was shifted from 196°C to 211°C.
Periodic stick-slip deformation of granular material under quasi-static conditions
- Danuta Leśniewska
- M. Pietrzak
- Michał Nitka
- Andrzej Tejchman-Konarzewski
2017 SpringerPlus
Artykuł omawia wyniki porównawcze między doświadczeniami z użyciem metody korelacji obrazów cyfrowych (DIC) a symulacjami z użyciem metody elementów dyskretnych (DEM) dla problemu przesuwającej się sztywnej ścianki w piasku. W doświadczeniach zaobserwowano w piasku deformację typu slip-stick, która nie została odtworzona w obliczeniach DEM..
Personal Branding and Brand Loyalty, Social Network Users Brand Identification: Polish-French Model
- Wioleta Kucharska
- Jérôme Thomas
2017
Social network brand sites are increasingly attracting the attention of scientists and managers intrigued by their potential application for brand value creation. The aim of this research, based on a multinational sample, is to fill the gap in understanding how users choose among social networking sites as an act of brand identification. The authors of the paper point to the fact that creating a personal brand is becoming more and more important to today's social media users and may be significant from the point of view of commercial brand value creation in social networks. The study presents a Customer Social Network Brand Identification Model (CsnBI) created for Polish and French populations, analysed with the use of a structural equal modelling method. Research sample based on 346 sample cases was gathered across Poland and France among Facebook users from May to June 2016. The presented model reveals that personal branding is a planned effect of social network users’ identification with a brand and that personal branding is stronger than the brand loyalty effect of the CsnBI. These findings lead to interesting practical implications. Namely, social network users’ identification with the brand does not have to lead to strong loyalty understood as purchasing a product on regular basis. As opposed to real-life participants, social network users do not need to own branded products to use their image. Thus, from a practical point of view, in order to build the capital of a commercial value on Facebook it is necessary to issue content which focuses on the users and their selfpresentation, and not on the brand. A commercial brand, therefore, in order to be effective, ought not to be the subject of the content presented on its own fan page, and ought not to be the centre of its attention. Our study helps understand mechanisms of brand value creation through social media in a better and more complete way.
Perspectives of Transport Systems Development in the Light of Radio Communication Systems Evolution Towards 5G
- Sławomir Gajewski
2017
In the paper conditions of development and implementation of transport systems with reference to the development of radio communication networks towards 5G are presented. First, general properties of next generation systems are mentioned and their architecture. Moreover, planned characteristics of B4G and 5G systems are depicted which can significantly contribute to the promotion and development of transport systems. In particular the paper covers new transmission mechanisms resulting from the development of the Internet of Things and M2M technology as well as related, for example: V2V or V2X. On the other hand, the issue has been analyzed against the background of the development of the so-called heterogeneous networks and used physical resource management mechanisms, reduction and coordination of inter-cell interference and handover problems. In particular attention was also drawn to the conditions of radio signals transmission in the context of high mobility of mobile terminals in transport systems.