2015 - Repozytorium publikacji - Politechnika Gdańska

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Rendezvous of heterogeneous mobile agents in edge-weighted networks
- Dariusz Dereniowski
- Ralf Klasing
- Adrian Kosowski
- Łukasz Kuszner
2015 Pełny tekst THEORETICAL COMPUTER SCIENCE
We introduce a variant of the deterministic rendezvous problem for a pair of heterogeneous agents operating in an undirected graph, which differ in the time they require to traverse particular edges of the graph. Each agent knows the complete topology of the graph and the initial positions of both agents. The agent also knows its own traversal times for all of the edges of the graph, but is unaware of the corresponding traversal times for the other agent. The goal of the agents is to meet on an edge or a node of the graph. In this scenario, we study the time required by the agents to meet, compared to the meeting time T_OPT in the offline scenario in which the agents have complete knowledge about each others speed characteristics. When no additional assumptions are made, we show that rendezvous in our model can be achieved after time O(n T_OPT ) in a n-node graph, and that such time is essentially in some cases the best possible. However, we prove that the rendezvous time can be reduced to Θ(T_OPT) when the agents are allowed to exchange Θ(n) bits of information at the start of the rendezvous process. We then show that under some natural assumption about the traversal times of edges, the hardness of the heterogeneous rendezvous problem can be substantially decreased, both in terms of time required for rendezvous without communication, and the communication complexity of achieving rendezvous in time Θ(T_OPT ).
Report no: WOiO /II/46/2015 - Construction node verification test, estimation of breaking load (shear force) and destruction form
- Jakub Kowalski
- Karol Niklas
2015
A new generation of tanks for LNG transportation has been designed. Mass reduction forced our customer to use three different materials: austenitic steel, aluminium alloy and LNG compressed wood between them. The expertise concerns structural node between tank foundation and suspension. Expertise contains: description of object of test, test principals, results and conclusions
Report no WOiO/II/67/2015 - Expertise about load capacity of twistlock foundation and sliding foundation
- Jakub Kowalski
2015
Customer delivered to Laboratory 17 elements - twist lock foundations and sliding lock foundations (ship equipment for container lashing). Elements were selected from production series. Each element was loaded for braking load. After test visual inspection had been performed. The expertise contains: description of tested elements, test assumptions, test stand, results and conclusions
Representation of magnetic hysteresis in a circuit model of a single-phase transformer
- Andrzej Wilk
2015 COMPEL-THE INTERNATIONAL JOURNAL FOR COMPUTATION AND MATHEMATICS IN ELECTRICAL AND ELECTRONIC ENGINEERING
The paper presents a mathematical model for the hysteresis phenomenon in a multi-winding single-phase core type transformer. The set of loop differential equations was developed for K-th winding transformer model where the flux linkages of each winding includes a flux common Φ to all windings as function of magneto motive force Θ of all windings. The first purpose of this paper is to determine a hysteresis nonlinearity involved in Φ(Θ) function using modified Preisach theory. The second purpose of this paper is to develop new analytical formula of Preisach Distribution Function (PDF). It is assumed in this paper that flux linkage characteristics Ψ(i) of each winding have nonlinear component due to the magnetization characteristic of the steel core and sum of linear components due to the self and mutual leakage fluxes. This nonlinear component of Ψ(i) characteristic can be expressed as a flux common Φ to all windings versus ampere-turns Θ of all windings. The nonlinear flux linkage characteristics Ψ(i) of the tested transformer are calculated from the set of measured terminal voltages and terminal currents. To simulate magnetic behaviour of the iron core the feedback scalar Preisach model of hysteresis is proposed which gives more accurate predictions than classical model. For this hysteresis model the PDF and feedback function are needed. The intend of this paper is to find these function as an analytical formulas which are convenient for numerical simulations. For identification of the PDF and feedback function parameters of the considered iron core of tested transformer the Levenberg-Marquardt optimization algorithm was used. The flux common to all windings is calculated by integrating the induced voltages of the appropriate windings. In this paper the PDF is proposed as a functional series including two dimensional Gauss expressions. In order to proper approximation of hysteresis nonlinearity of the tested iron core the first three terms of functional series of the PDF have been used. In the optimization algorithm only initial and descending limiting hysteresis curves Φ(Θ) were utilized. The feedback function for proposed hysteresis model is assumed as third order polynomial. The hysteresis model has been successfully validated by comparing the calculated and measured results of Φ(Θ) hysteresis curves. This hysteresis model can be used in transient and steady state simulations of tested transformer taking into account the hysteresis phenomenon.
Research and Analysis of Accuracy of Location Estimation in Inertial Navigation System
- Piotr Rajchowski
- Krzysztof Cwalina
- Jarosław Sadowski
2015 Applied Mechanics and Materials
In the article the research and analysis of digital signal processing and its influence on accuracy of location estimation in developed inertial navigation system was presented. The purpose of the system is to localize moving people in indoor environment. During research a measuring unit for recording selected movement parameters was made. In the article were also described author’s inertial navigation algorithms.
Research and Development at the Department of Energy and Industrial Apparatus of Gdansk University of Technology
- Dariusz Mikielewicz
- Janusz Cieśliński
- Jan Stąsiek
- Jan Szantyr
2015
In the paper presented are the research and development activities at the Department of Energy and Industrial Apparatus of Gdansk University of Technology
Research on assessment of bolted joint state using elastic wave propagation
- Rafał Kędra
- Magdalena Rucka
2015 Pełny tekst Journal of Physics : Conference Series
The work contains results of experimental investigation of elastic wave propagation in a bolted single-lap joint. Tests were carried out for the excitation perpendicular to the connection plane. In experimental studies, PZT transducers were used for both excitation and registration of ultrasonic waves. The analyses took into account varying contact conditions between the elements of the connection depending on the value of the prestressing force. The influence of loosening/tightening of bolts on the energy dissipation was analysed. The experimental results proved the influence of bolt torque on quantitative characteristics of the signals. To improve the diagnostic possibilities only the initial parts of signals were analysed.
Resilient Routing in Communication Networks
- Jacek Rak
2015
This important text/reference addresses the latest issues in end-to-end resilient routing in communication networks. The work highlights the main causes of failures of network nodes and links, and presents an overview of resilient routing mechanisms, covering issues related to the Future Internet (FI), wireless mesh networks (WMNs), and vehicular ad-hoc networks (VANETs). For each of these network architectures, a selection of novel approaches are described, followed by evaluation of their characteristics.
Resonance Frequency Calculation of Spherical Microstrip Structure Using Hybrid Technique
- Adam Kusiek
- Rafał Lech
- Piotr Kowalczyk
- Wojciech Marynowski
2015
In this paper the spherical microstrip structure is considered. The structure is composed of a metallic patch with an arbitrary shape placed on a dielectric coated metallic sphere. In the analysis the hybrid technique is utilized. In this approach the finite-difference technique is applied in a cavity model to determine the current basis functions on the patch. Next, using method of moments, the resonance frequency of the structure and radiation pattern are calculated. The results of the proposed approach are compared with those obtained from commercial software and those published in the literature.
Resonance in Rectangular Microstrip Structure Loaded with a Pseudochiral Medium Layer
- Rafał Lech
- Adam Kusiek
- Wojciech Marynowski
- Jerzy Mazur
2015
A rectangular microstrip structure with multilayer substrate containing dielectric and pseudochiral medium layers is studied in this paper. The effect of Omega medium layer location in the substrate and its thickness on the complex resonant frequency of the rectangular microstrip structure is investigated.
Resourcing in social enterprise – content analysis of 'good practices' profiled in 'Atlas of social economy' in Poland
- Marzena Starnawska
2015
The aim of this paper is to analyze and show what processes accompany resource mobilization among social enterprises. For this, the author uses a sample of 25 ‘good practice’ examples selected and presented in ‘Atlas of social economy’ in Poland, in the most popular and well-established knowledge base web portal on social economy and social enterprise in Poland. The author makes an attempt at deconstructing the profiles of the featured ‘good practices’ and undertakes content analysis to provide insights into the processes and strategies behind resourcing.
Responsible Court in the Global World - Managerism or Managerialism
- Sylwia Morawska
- Przemysław Banasik
2015 Pełny tekst Oeconomia Copernicana
One can look at the improvement of the effectiveness and efficiency of the justice system from three perspectives: macro, mezo, and micro. After all, the general goal is to enhance the effectiveness and efficiency of the justice system as a whole (the macro perspective), the courts (the mezo scale), and court proceedings (the micro scale). The need to improve the effectiveness and efficiency of the justice system was noticed in the Strategy of modernization of justice in Poland in the years 2014–2020 prepared by the Ministry of Justice incorporates the three abovementioned perspectives. From the perspective of this paper, emphasis has been placed on courts. The Strategy, as a matter of fact, assumes that the improvement of the effectiveness and efficiency of courts may occur by introducing a model of management based on the idea of “managerialism” to run them. Effective and efficient courts, just like the proceedings they operate, are particularly important in the face of globalization, regulatory arbitration, as well as forum shopping.
Restrukturyzacja, upadłość i egzekucja jako szansa utrzymania trwałości przedsiębiorstw
- Przemysław Banasik
- Sylwia Morawska
2015
W rozdziale rozważania skoncentrowano wokół tezy, że regulacje umożliwiające przedsiębiorcy restrukturyzację, zapobiegające jego upadłości oraz zapewniające skuteczną egzekucję, stanowią gwarancję bezpieczeństwa obrotu gospodarczego oraz są istotnymi determinantami sukcesu przedsiębiorczości. W związku z powyższym przeprowadzono analizę prawną oraz ekonomiczną restrukturyzacji oraz egzekucji wskazując na ich silne i mocne strony. W podsumowaniu sformułowano rekomendacje i wnioski.
Retrieval of Heterogeneus Sevices in C2NIWA Repository
- Julian Szymański
2015 Pełny tekst TASK Quarterly
The paper reviews the methods used for retrieval of information and services. The selected approaches presented in the review inspired us to build retrieval mechanisms in a system for searching the resources stored in the C2NIWA repository. We describe the architecture of the system, its functions and the surrounding subsystems to which it is related. For retrieval of C2NIWA sevices we propos three approaches based on: keyword search, hierarchical catalog and searching with the use of a specification of meta values. The proposed funcjonality allows us to increase the visibility of the University competebces. We propose a module for managing external proposals to carry out cooperative projects using the know-how of the University.
Re-use of historic wooden verandas in Sopot, Poland
- Jacek Poplatek
- Jarosław Bąkowski
2015
Sopot is the best-known seaside resort in Poland. The city is unique with regard not only to its location and natural values, but also its interesting architecture, which dates back to the end of the 19th and the beginning of the 20th century. Wooden verandas are one of the characteristic features of Sopot architecture. Their origin is associated with the Swiss style, which was fashionable at the turn of the 20th century and quite common in numerous European resorts of the day. Verandas were used as summer parlours, where the guests could eat their meals and protect themselves from the caprices of summer weather. After World War II the majority of private lodging houses, tenement houses and residences became municipal property. During the following decades the technical condition of the houses, with no owners to ensure their proper maintenance, steadily deteriorated. This was the situation until the beginning of the 1990s, when Poland regained its sovereignty and became a fully democratic country. Revitalisation activities aimed at revival of the former splendour and cultural value of historic houses in Sopot were launched. This paper defines the basic types of historic verandas and their characteristic features, as well as the ways in which they were placed on the façades, depending on the form of the building. The main part of the article describes the possibilities of modernizing verandas and adjusting them to user requirements currently applied to living areas. It also refers to the issues of construction, thermal protection, fire protection and energy saving in the context of sustainable development.
Revalorisation of Modernist and Social Modernist Interiors in Gdynia
- Anna Orchowska-Smolińska
2015
In the 1920s and 1930s, elaborate designing of prestigious interiors of public buildings, shops or tenement houses was important challenge for every architect who respected theri work. Apart from creating, at the design decor, the designers usually made sure that their concept was executed in every single detail. Only an overall aestetic solution could form a complete picture of a unique pieceod architecture.
Review of hydrogen production technologies for automotive sector – thermodynamic analysis of energy and exergy losses
- Tomasz Kowalczyk
- Janusz Badur
2015 Logistyka
Few recent years has shown that hydrogen technology has a good chance to replace petroleum technology in automotive sector. However, hydrogen in pure form practically does not occur on Earth. That is why H2 form is used only as an energy carrier and it must be produced using another source of energy form water or hydrocarbon fuels. In this paper short overview of hydrogen production technology has been presented, with energy and exergy analysis of four chosen technologies. Water and steam splitting using PEM as efficient and technically the simplest methods, SOEC as an industrial high effective thermoelectric process and thermochemical decomposition as non-electric alternative.
Review of sewage sludge management: standards, regulations and analytical methods
- Bartłomiej Cieślik
- Jacek Namieśnik
- Piotr Konieczka
2015 Pełny tekst JOURNAL OF CLEANER PRODUCTION
This article presents the most popular methods of sewage sludge management and associated unit operations and processes referring to them. The most popular methods are: Reclamation and adaptation of lands to specific needs; plant cultivation not intended for consumption or for production of food; usage in agriculture; usage in building; recovery of phosphorus, rare earth metals or fats and usage in industry; producing combustible pellets, granulates or other usable materials such as absorbents; and storage on territory of treatment plant and landfills. Processing connected with stabilization leads to generation of materials which might be contaminated with variety of organic compounds. Since this type of management generally assumes introduction of processed sludge to the ground, it can cause soil contamination with unknown compounds of organic origin. However, thermal processing of raw sewage sludge essentially excludes such possibility. Majority of organic matter is transformed into simple, mineralized form. In this case the most problematic issue is sewage sludge ash contamination with heavy metals. Although, determination of heavy metals in ashes is much simpler than determination of organic compounds. Chemical analysis can be very useful to asses environmental safety of processed and managed sewage sludge. That is why there is a significant quantity of used analytical techniques which are likely to support the processes of designing and implementing new economically and environmentally reasonable ways of re-using sewage sludge. Further, the process of technological utilization of sewage sludge conducted in Wastewater Treatment Plant “Wschod” in Gdansk is described. Recently technological line was upgraded. Now excessive sewage sludge is anaerobic digested with biogas recovery. Fermentation residues are incinerated in fluidized bed furnace. Ashes are cemented and land filled. Gdanska Infrastruktura Wodocia˛gowo-Kanalizacyjna, which is owner of the treatment plant “Wschod“ is planning development strategy for the implementation of a pro-ecological management method connected with production of light construction materials and phosphorus recovery. Management of thermal treated sewage sludge is simpler and cheaper than non-thermal management, especially in case of large amounts of treated sewage sludge like in Wastewater Treatment Plant “Wschod”...
Revision of Biological Methods for Determination of EDC Presence and Their Endocrine Potential
- Błażej Kudłak
- Natalia Jatkowska
- Katarzyna Owczarek
- Zofia Mazerska
- Jacek Namieśnik
2015 CRITICAL REVIEWS IN ANALYTICAL CHEMISTRY
Endocrine-disrupting compounds (EDC) are chemicals responsible for disturbances in the hormonal balance of organisms. This group of chemicals includes both egzogenic and endogenic substances or their mixtures that impact functioning of natural hormones in organisms. In the available literature one can find information on the application of chromatographic and related techniques in the analysis of environmental samples for detection, identification, and quantitation of a wide spectrum of chemicals posing endocrine properties. On the other hand, more and more biotests are being developed to determine endocrine potency of environmental samples due to development of genetic engineering methods and specific detection methods of cells’ response to the action of particular chemicals of interest. This article presents revisions of the most novel methods for this potency determination with application to biological elements.
Rewolucja w czytania ?: Refleksje na temat czytelnictwa w Bibliotece Uczelnianej Politechniki Gdańskiej
- Tatiana Andrzejewska
- Bożena Hakuć
- Bożena Kray
2015
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