displaying 1000 best results Help
Search results for: NECESSARY AND SUFFICIENT CONDITION
-
Design of novel microstrip directional coupler for differential signal decoupling
PublicationThis study describes a concept of a novel microstrip directional coupler for differential signal decoupling, which can be used to digital signal overhearing on printed-circuit-boards. The complete design method is proposed with rules given analytically. Considered methodology is suitable for synthesis of couplers with low coupling factors, which have negligible influence on the transmission in main line. Theoretical considerations...
-
Energy Security of Polish Consumers in 2004-2021
PublicationTheoretical background: Energy security is one of the most important components of economic security. It is influenced not only by access to energy sources and the economic situation of the state and the individual consumer. The authors adopted the definition of energy security of an individual consumer as included in the UN report. It states that energy security of an individual consumer is guaranteed when the average consumer...
-
EGNOS-based GNSS receiver for precise positioning in restricted areas
PublicationPositioning accuracy is very important in many areas, whereas the typical GPS receiver accuracy is often not sufficient. The European Geostationary Navigation Overlay Service (EGNOS), Europe’s first venture into satellite navigation, improves the open public service offered by the Global Positioning System (GPS). As a satellite navigation augmentation system, EGNOS improves the accuracy of GPS by providing a positioning accuracy...
-
Robust amplification of Santha-Vazirani sources with three devices
PublicationWe demonstrate that amplification of arbitrarily weak randomness is possible using quantum resources. We present a randomness amplification protocol that involves Bell experiments. We find a Bell inequality which can amplify arbitrarily weak randomness and give a detailed analysis of the protocol involving it. Our analysis includes finding a sufficient violation of Bell inequality as a function of the initial quality of randomness....
-
Recognition of hazardous acoustic events employing parallel processing on a supercomputing cluster . Rozpoznawanie niebezpiecznych zdarzeń dźwiękowych z wykorzystaniem równoległego przetwarzania na klastrze superkomputerowym
PublicationA method for automatic recognition of hazardous acoustic events operating on a super computing cluster is introduced. The methods employed for detecting and classifying the acoustic events are outlined. The evaluation of the recognition engine is provided: both on the training set and using real-life signals. The algorithms yield sufficient performance in practical conditions to be employed in security surveillance systems. The...
-
Evaluation of Open Source SIEM for Situation Awareness Platform in the Smart Grid Environment
PublicationThe smart grid as a large-scale system of systems has an exceptionally large surface exposed to cyber-attacks, including highly evolved and sophisticated threats such as Advanced Persistent Threats (APT) or Botnets. When addressing this situation the usual cyber security technologies are prerequisite, but not sufficient. The smart grid requires developing and deploying an extensive ICT infrastructure that supports significantly...
-
Studying the Behaviour of Pedestrians and Drivers Within Pedestrian Crossings
PublicationEvery 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 re-lations between pedestrians and motorists...
-
Building modernization located in the conservation protection zone in the aspect of technical conditions
PublicationThe paper presents a description of the technical condition of the building after many years of operation and analyzes the impact of the current use and the lack of regular periodic repairs on the technical efficiency of the building. The influence of the technical solutions applied during the construction of the building on the current limitations related to the planned, target change in the way of use was discussed. Variant conceptual...
-
Diagnostics of bolted lap joint using guided wave propagation
PublicationThe paper presents numerical and experimental analyses of elastic waves propagation in a bolted lap joint. In experimental investigations condition assessment of the joint was performed with the use of symmetric waves excited by a piezoactuator. Numerical calculations were conducted in commercial finite element method software Abaqus. The influence of number of bolts and the value of the initial stress on recorded signals was examined....
-
Historical crane on the redesigned original trestle bridge as a memorial of Gdansk Shipyard
PublicationThe paper includes selected aspects of the study, whose goal is to hold the historical crane 642-24 in its current location after the modification of trestle bridge static scheme. The scope of the paper includes the assessment of current technical condition of the object, a presentation of FEM analyses, a description of the assumed load cases, results of the static calculations, checking the effort of construction elements, global...
-
PLANOWANIE BEZPIECZNYCH I „ZIELONYCH” SYSTEMÓW KOMUNIKACYJNYCH
PublicationIn order to achieve balanced forms of urban infrastructure, which ensure comfort, safety and spatial order, when designing new solutions it is necessary to adopt a multi-facet approach which will combine everything that the local residents need but will respond harmoniously to the existing cultural landscape. It is therefore necessary to work out complex undertakings for the sake of planning and developing urban space. Coherent...
-
Public Spaces - Coexistence and Participation
PublicationThe paper is an attempt to answer two questions: (1) how to develop positive social relations and citizenship among residents of cities in Poland and (2) howsuitable shaping of public space affects the activation and integration of local residents.The specificity of the post-war process of urbanization in Poland - a country traditionally agricultural - was its political dimension (forced 'nationalisation' of agriculture and industrialization...
-
Photographic documentation of the Palace in Osiek (Oświęcim County, Lesser Poland) at the turn of the 19th and 20th centuries
Open Research DataThis dataset presents photographic documentation of the Palace settled in Osiek (Oświęcim County, Małopolskie Voivodeship – Lesser Poland) from the first half of the 19th century. In 1972, the Palace was listed as a Palace and park complex. The complex consists of a palace, the outbuilding "Kasztel" (Castellum), the "Judge's House" outbuilding, the...
-
Cities that obtain the highest revenues from PIT in 2021 in PLN billion
Open Research DataTax issues play an important role in the economy of each country, its citizens and economic entities that operate on the market. Taxes are the main instrument of the state's influence on the economy, as they cover almost all natural and legal persons that operate on the market.
-
Verification of the criteria for evaluation of water and frost resistance of asphalt concrete
PublicationThe paper presents the results of field investigation - condition survey of existing pavements and the results of laboratory tests on water and frost resistance of samples cored from the these pavements. The purpose of testing was to verify the criteria for evaluation of the resistance of asphalt concrete to the action of water and frost by way of comparing the results of field and laboratory tests, followed by evaluation of their...
-
3D Buckling Analysis of a Truss with Horizontal Braces
PublicationThe present research is devoted to the study of out–of–plane buckling of a truss with horizontal braces. The truss is a model of real roof truss scaled by factor 1=4. A linear buckling and a non–linear analysis with geometric and material non–linearity were carried out. The truss buckling and limit load for different stiffnesses and number of braces are found. Numerical analysis are verified by experiment. Threshold bracing stiffness condition...
-
Distorsional analysis of I-section beam
PublicationAn elastic stiffness matrix was derived in the case of distortion of a restrained thin-walled I-section beam using the minimum total stationary elastic energy condition. The function describing the angle of distortion was adopted form the solution of differential equation in the case of restrained distortion. The example presented in the paper helps to assess the correctness of the proposed solution. The proposed elastic stiffness...
-
Conjugated control of triple active bridge converter with common HFT
PublicationPaper presents synthetic analyses of single input, dual output DC/AC/DC converter with common high frequency transformer. Rise the problem of cross-coupling power flows between secondary terminals, under asymmetrical control operating condition. It also proposes a new approach to converter control, based on conjugated phase shift modulation and defines its limitations. Finally, the developed control technique was verified by simulation...
-
ANALIZA STANU TECHNICZNEGO RUROCIĄGÓW: WODY PRZeMYSŁOWEJ I SOLANKI
PublicationPracę wykonano na zlecenie Przedsiębiorstwa Badawczo-Wdrożeniowego "HYDRO-POMP" Sp. z o.o. ul. Wróblewskiego 19, 93-578 Łódź. Wykonawcą zlecenia jest Politechnika Gdańska, Wydział Chemiczny, Katedra Elektrochemii, Korozji i Inżynierii Materiałowej, 80-233 Gdańsk, ul. G. Narutowicza 11/12. Celem pracy była analiza stanu technicznego i badania dwóch rurociągów: solanki oraz wody przemysłowej. Badania wykonywano w warunkach terenowych...
-
MnCo2O4 deposited by spray pyrolysis as a protective layer for stainless steel interconects
PublicationStainless steel interconnects working in Solid Oxide Fuel Cells stacks are exposed to high temperature resulting in their corrosion. Protective layers for the hydrogen and oxygen sides are necessary to protect the interconnect material, prolongate the stack lifetime and maintain the output power. In this paper MnCo2O4 protective layer for the oxygen side of the interconnect is deposited by spray pyrolysis and is examined.
-
Automatic tuning of a resonant circuit in wireless power supply systems for biomedical sensors
PublicationIn this paper, a tuning method of a resonant circuit suited for wireless powering of miniature endoscopic capsules is presented and discussed. The method allows for an automatic tuning of the resonant frequency and matching impedance of a full wave rectifier loading the resonant circuit. Thereby, the receiver tunes so as to obtain the highest power efficiency under given conditions of transmission. A prototype receiver for wireless...
-
The role of water in deep eutectic solvent-base extraction
PublicationDeep eutectic solvents (DESs) are currently being used in different sectors, such as electrochemistry, electrodeposition, organic synthesis, nanoparticle preparation, bioactive compound separation, etc. Their use in analytical chemistry has only recently begun to expand. Despite the publication of a sufficient number of DES-based analytical extraction procedures, some details, such as interaction of DESwith the sample and target...
-
Distortional buckling of composite thin-walled columns of a box-type cross section with diaphragms
PublicationDistortional buckling of axially compressed columns of box-like composite cross sections with andwithout internal diaphragms is investigated in the framework of one-dimensional theory. The channel membersare composed of unidirectional fibre-reinforced laminate. Two approaches to the member orthotropic materialare applied: homogenization based on the theory of mixture and periodicity cells, and homogenization basedon the Voigt–Reuss...
-
QUALITY GAPS IN HIGHER EDUCATION FROM THE PERSPECTIVE OF STUDENTS
PublicationThe presented research work relates to the category of quality in higher education. This article aims to present the determinants of the quality of education in the context of international standards. The background of the considerations is the Bologna Declaration and the European Higher Education Area. The results of the research carried out with the use of the nominal group method and the data analysis carried out based on the...
-
Lean Startup as a New Way of Managing Technology Ventures Illustrated by the Example of Wlcome App
PublicationThe dot-com bubble in the 1990s made the technology industry aware that even excellent ideas backed by amazing teams are not sufficient to ensure a startup’s success. The biggest risk of startups is that they have to operate within many uncertainties, their market and customers are unknown, and their business model is not yet validated. Therefore, successful execution of such a venture requires a rigorous process that would validate...
-
Positive solutions to second-order differential equations with dependence on the first-order derivative and nonlocal boundary conditions
PublicationIn this paper, we consider the existence of positive solutions for second-order differential equations with deviating arguments and nonlocal boundary conditions. By the fixed point theorem due to Avery and Peterson, we provide sufficient conditions under which such boundary value problems have at least three positive solutions. We discuss our problem both for delayed and advanced arguments α and also in the case when α(t)=t, t∈[0,1]....
-
On optimal tracking of rapidly varying telecommunication channels
PublicationWhen parameters of mobile telecommunication channels change rapidly, classical adaptive filters, such as exponentially weighted least squares algorithms or gradient algorithms, fail to estimate them with sufficient accuracy. In cases like this, one can use identification methods based on explicit models of parameter changes such as the method of basis functions (BF). When prior knowledge about parameter changes is available the...
-
Biological responses to environmental contamination. How can metal pollution impact signal honesty in avian species?
PublicationEnvironmental pollution, for example with metals, can significantly affect the ecosystem balance leading to severe changes. Biologically active pigments are relevant for the appearance and condition of birds. Melanin and carotenoid particles are the most frequently deposited pigments in avian integument. They are responsible for the majority of colors of bird plumage. The phenotypic expression can be affected by metal contamination....
-
USING ARTIFICIAL NEURAL NETWORKS FOR PREDICTING SHIP FUEL CONSUMPTION
PublicationIn marine vessel operations, fuel costs are major operating costs which affect the overall profitability of the maritime transport industry. The effective enhancement of using ship fuel will increase ship operation efficiency. Since ship fuel consumption depends on different factors, such as weather, cruising condition, cargo load, and engine condition, it is difficult to assess the fuel consumption pattern for various types...
-
Storage of High-Strength Steel Flux-Cored Welding Wires in Urbanized Areas
PublicationThe condition of the consumables is a key factor determining the waste reduction in the welding processes and the quality of the welded joint. The paper presents the results of tests of four types of fux-cored wires dedicated for welding high-strength steels, stored for 1 month and 6 months in Poland in two urbanized areas: in a large seaside city (Gdańsk) and in Warsaw, located in the center of the country. The wires were subjected...
-
Problems of modelling toxic compounds emitted by a marine internal combustion engine for the evaluation of its structure parameters
PublicationThe paper presents the possibility of using an analytical study of the engine exhaust ignition to evaluate the technical condition of the selected components. Software tools available for the analysis of experimental data commonly use multiple regression model that allows the study of the effects and iterations between model input quantities and one output variable. The use of multi-equation models gives a lot of freedom in the...
-
Stability of roof trusses stiffened by corrugated sheets
PublicationThe present parametric study is devoted to the stability analysis of a set of trusses stiffened by decking of corrugated steel sheets. For different parameters of corrugated sheets the critical loading of the roof is calculated. In the parametrical analysis the threshold bracing condition of the roof is obtained. Then the geometrically non-linear analysis of trusses braced by corrugated sheets was conducted. As a results of non-linear...
-
Determining the leakage current resistive component by the orthogonal vector method
PublicationThe measurement of the metal – oxide surge arresters (MOSA) leakage current and the analysis of its components is a key diagnostic criterion according to technical standards. During on site MOSA condition assessment, the easy way is based on the measurement only leakage current, without the inconvenient live working measurements of supply voltage. Orthogonal vectors method of determination the resistive leakage current is presented....
-
Dynamic GNSS Mission Planning Using DTM for Precise Navigation of Autonomous Vehicles
PublicationNowadays, the most widely used method for estimating location of autonomous vehicles in real time is the use of Global Navigation Satellite Systems (GNSS). However, positioning in urban environments using GNSS is hampered by poor satellite geometry due to signal obstruction created by both man-made and natural features of the urban environment. The presence of obstacles is the reason for the decreased number of observed satellites...
-
Arterial cannula shape optimization by means of the rotational firefly algorithm
PublicationThe article presents global optimization results of arterial cannula shapes by means of the newly modified firefly algorithm. The search for the optimal arterial cannula shape is necessary in order to minimize losses and prepare the flow that leaves the circulatory support system of a ventricle (i.e. blood pump) before it reaches the heart. A modification of the standard firefly algorithm, the so-called rotational firefly algorithm,...
-
The database of localization and expression of aquaporin 3 (AQP3), aquaporin 7 (AQP7) and aquaporin 9 (AQP9) in the male reproductive system in cattle. Morphometric studies. Localization of zinc finger transcription factor GATA-4.
Open Research DataThe data present research results being part of the OPUS-22 project entitled “In search of new markers of male fertility in cattle. Aquaporins expression in the reproductive organs and sperm of the bulls (Bos taurus)” obtained from the National Science Center in Poland (grant no. 2021/43/B/NZ9/00204). The aim of this part of the project was (i) to determine...
-
Tensile test of 1.4571 / X6CrNiMoTi17-12-2 / AISI 316Ti grade austenitic steel
Open Research DataShip structures and their components are build mainly of steel. Hull steel is used to build the hull structure. Some structural elements, such as RSW (Refrigerated See Water) tanks, or LNG (Liquid Natural Gas) tanks - gas transported at temperatures below -162° C, are build from austenitic steels. Austenitic steels have a different microstructure and...
-
Implementing decisional trust: a first approach for smart reliable systems
PublicationIn this article, we introduce the necessary elements that must be integrated in order to achieve a decisional technology that is trustworthy. Thus, we refer to such technology as decisional trust. For us, decisional trust can be achieved through the use of elements such as the decisional DNA, reflexive ontologies, and security models; and therefore, we present in this article a framework that was used for the implementation of...
-
Green, blue and energy in cities
PublicationThe article refers to the implementation of blue-green infrastructure in cities, with particular emphasis on the aspect of rainwater and energy management. The article presents the advantages of water and greenery in the city and gives examples of engineering solutions used, both the more popular (including green and biosolar roofs), as well as experimental solutions, which are an interesting and necessary alternative in the era...
-
Ocena stanu technicznego konstrukcji zgarniaczy będących na wyposażeniu osadników wstępnych Grupowej Oczyszczalni Ścieków „DĘBOGÓRZE
PublicationOsadniki wstępne typu DORRA – 4 szt., o pojemności 1830 m3, wyposażone są w elementy mechaniczne do kierunkowego przemieszczania się osadu w kierunku leja centralnego. Celem pracy jest ocena stany technicznego części mechanicznej, a w szczególności: - konstrukcji zespołu zgarniania części pływających oraz osadu. - zespołu napędu i sterowania, - zespołu napędu i jazdy. Pierwsze dwa zespoły będą oceniane również z punktu widzenia...
-
Framework for extracting rails and setting-out railway line axis based on UAV photogrammetric measurements
Open Research DataTechnical diagnostics enables assessing the current technical condition of a railway line and adjacent infrastructure, and to forecast its changes over a specific time horizon. One of its elements is the periodic monitoring of rail position and their geometry. The data set presents a new framework for the setting-out of a railway track axis. The process...
-
Photographic documentation of St. Andrew’s Church in Osiek (Oświęcim County, Lesser Poland) at the turn of the 19th and 20th centuries
Open Research DataThis dataset presents photographic documentation of the St. Andrew’s Church settled in Osiek (Oświęcim County, Małopolskie Voivodeship – Lesser Poland), built in 1538-1549. This wooden church is a late-gothic Silesian-style building. Inside the church are the baroque main altar and the rococo pulpit, shaped like a boat from the second half of the 18th...
-
Blade Section Prpfile Array Lifting Surface Design Method for Marine Screw Propeller Blade
PublicationThe lifting surface model is widely used in screw propeller design and analysis applications. It serves as a reliable tool for determination of the propeller blade mean line and pitch distribution. The main idea of this application was to determine the blade shape that would satisfy the kinematic boundary condition on its surface with the prescribed bound circulation distribution over it. In this paper a simplified lifting surface...
-
W-like bound entangled states and secure key distillation
PublicationWe construct multipartite entangled states with underlying W-type structuresatisfying positive partial transpose (PPT) condition under any (N −1)|1 partition. Then we showhow to distill a N-partite secure key from the states using two different methods: direct applicationof local filtering and novel random key distillation scheme in which we adopt the idea from recentresults on entanglement distillation. Open problems and possible...
-
Research on the wear evenness of the tool in flat lapping
PublicationIn this paper, the dimensionless distribution of the material removal stock and the trajectories of abrasive grains cutting in single-sided lapping process are presented. They were numerically simulated based on the tribological model and kinematics equations. It can be observed that the trajectories geometry of single abrasive as well the velocities have a great influence on the final geometrical deviation. During machining, the...
-
A simple approach to heat exchanger sizing optimisation by means of entrophy generation minimisation
PublicationIn the paper an attempt is presented to find the method of optimization of microtube diameter with respect to optimal thermal-hydraulic conditions in the single-phase shell-and-tube heat exchangers. The approach is based on consideration of pumping power at the condition of maximum heat transfer by the heat exchanger tube system. In the optimization method the tube diameter is first specified and then appropriate calculations are...
-
Ocena zasobów oraz weryfikacja granic obszaru ochronnego GZWP nr 133 Młotkowo za pomocą numerycznego modelu przepływu wód podziemnych
PublicationModel Głównego Zbiornika Wód Podziemnych powstał w celu dokonania oceny dostępnych zasobów wód oraz zweryfikowania granic strefy ochronnej. GZWP Młotkowo jest położony w południowej części Pojezierza Krajeńskiego. Ze względu na konieczność weryfikacji granic zbiornika wyznaczonych przez Kleczkowskiego i in. (1990) do badań modelowych przyjęto obszar cztery razy większy niż rozmiar GZWP. W celu osiągnięcia najbardziej wiarygodnych...
-
Shell model of multiple-row moment I-section end-plate joint
PublicationThe paper deals with a problem of application of shell elements in the models of multiple-row moment end-plate connections. The extended connection of I-section with a cross-section W760x265x220 made of steel S355 was analyzed. Comparison analysis of FEM, complex volume and shell models has been done. Three cases with different end-plate thickness: 14, 18 and 36 mm were analyzed and compared with the reference results. Comparison...
-
Pylon foundation of a cable stayed bridge at the motorway ring road of Wrocław
PublicationThe largest bridge of the motorway ring road of Wroclaw is a cable stayed bridge over the Odra river near Rędzin. Due to hydrogeological conditions of the ground it was not convenient to use standard bored piles of high length. Instead shorter piles were applied with additional improvement by cement injections at the pile toes. This decision was possible by extending ground investigation program and application of numerical modeling...
-
Straightened characteristics of McKendrick-von Foerster equation
PublicationWe study the McKendrick-von Foerster equation with renewal (that is the age-structured model, with total population dependent coefficient and nonlinearity). By using a change of variables, the model is then transformed to a standard age-structured model in which the total population dependent coefficient of the transport term reduces to a constant 1. We use this transformation to get existence, uniqueness of solutions of the problem...