Filtry
wszystkich: 1138
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Wyniki wyszukiwania dla: LOW-SULPHUR MARINE FUELS, ENGINE TESTS, DYNAMIC FEATURES
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Impact of Propeller Emergence on Hull, Propeller, Engine, and Fuel Consumption Performance in Regular Head Waves
PublikacjaIn this study, the impact of propeller emergence on the performance of a ship (speed), propeller (thrust, torque, and RPM), a diesel engine (torque and RPM) and fuel consumption are analysed under severe sea conditions. The goal is to describe the variation in the system variables and fuel consumption rather than analysing the motion of the ship or the phenomenon of propeller ventilation in itself. A mathematical model of the...
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Testing a Variety of Features for Music Mood Recognition. Testowanie zestawu parametrów w celu rozpoznawania nastroju w muzyce
PublikacjaMusic collections are organized in a very different way depending on a target, number of songs or a distribution method, etc. One of the high-level feature, which can be useful and intuitive for listeners, is “mood”. Even if it seems to be the easiest way to describe music for people who are non-experts, it is very difficult to find the exact correlation between physical features and perceived impressions. The paper presents experiments...
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Risk criteria for sea-going ships arising from the operation of the main engines' crankshaft - conecting rod - piston systems
PublikacjaIn the article the risk criterion for sea-going ships arising from the operation of the main engines' crankshaft - connecting rod - piston systems is proposed. These criterion is based on the procedures recommended in the Formal Safety Assessment method developed under the auspices of International Maritime Organization (IMO). First of all the collective risk criterion for ship has been proposed. In the next step, the share of...
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A comprehensive survey on low-cost ECG acquisition systems: Advances on design specifications, challenges and future direction
PublikacjaAvailability of low-cost, reliable, and portable Electrocardiography (ECG) devices is still very important in the medical world today. Despite the tremendous technological advancement, Cardiovascular Diseases (CVDs) remain a serious health burden claiming millions of lives on an annual basis globally. This is more prevalent in Low and Middle-Income Countries (LMICs) where there are huge financial instability and lack of critical...
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On the Use of Selected 4th Generation Nuclear Reactors in Marine Power Plants
PublikacjaThis article provides a review of the possibility of using different types of reactors to power ships. The analyses were carried out for three different large vessels: a container ship, a liquid gas carrier and a bulk carrier. A novelty of this work is the analysis of the proposal to adapt marine power plants to ecological requirements in shipping by replacing the conventional propulsion system based on internal combustion engines...
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Mercury in the Polish part of the Baltic Sea: A response to decreased atmospheric deposition and changing environment
PublikacjaOur review of the literature showed that since the beginning of the socio-economic transformation in Poland in the 1990s, the downward trend in Hg emissions and its deposition in the southern Baltic Sea was followed by a simultaneous decrease in Hg levels in water and marine plants and animals. Hg concentrations in the biota lowered to values that pose no or low risk to wildlife and seafood consumers. However, in the first decade...
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Synteza układu sterowania statkiem morskim dynamicznie pozycjonowanym w warunkach niepewności
PublikacjaNiniejsza monografia obejmuje zagadnienia związane z syntezą układu dynamicznego pozycjonowania statku w środowisku morskim z zastosowaniem wybranych nieliniowych metod sterowania. W ramach pracy autorka rozważała struktury sterowania z zastosowaniem wektorowej adaptacyjnej metody backstep oraz metod jej pokrewnych, takich jak regulatory MSS (ang. multiple surface sliding), DSC (ang. dynamic surface control), NB (ang. neural backstepping)....
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Low-Voltage Low-Power Filters with Independent ω0 and Q Tuning for Electronic Cochlea Applications
PublikacjaAn acoustic second-order low-pass filter is proposed for filter banks emulating the operation of a human cochlea. By using a special filter structure and an innovative quality (Q)-factor tuning technique, an independent change of the cutoff frequency (ω0) and the Q-factor with unchanged gain at low frequencies is achieved in this filter. The techniques applied result in a simple filter design with low Q-factor sensitivity to component...
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ADAPTIVE BACKSTEPPING TRACKING CONTROL FOR OVER-ACTUATED DP MARINE VESSEL WITH INERTIA UNCERTAINTIES
PublikacjaDesigning a tracking control system for an over-actuated dynamic positioning marine vessel in the case of insufficient information on environmental disturbances, hydrodynamic damping, Coriolis forces and vessel inertia characteristics is considered. The designed adaptive MIMO backstepping control law with control allocation is based on Lyapunov control theory for cascaded systems to guarantee stabilization of the marine vessel...
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The dynamic performance analysis of the Micro-turbine's rotor supparted on slide and roling element bearings
PublikacjaThis article presents the results of investigations of dynamic characteristics of a small-dimension rotor with slide and rolling element bearings. The object of investigations was the rotor-bearing system designed for the ORC based low-power steam micro-turbine. The investigations were performed using MESWIR series programs, as well as commercial FEA software ABAQUS and MADYN 2000. The results of modal analysis of the micro-rotor...
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Semi complex navigation with an active optical gesture sensor
PublikacjaThis paper presents the methods of diversified touchless interactions between a user and a mobile platform utilizing the optical gesture sensor. The sensor uses 8 photodiodes to measure the reflected light in the active mode (using embedded LEDs) or it measures shadows caused by fingers in the passive mode. Several algorithms were implemented: automatic mode switching, adaptive illumination level compensation, resolution improvements...
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Influence of lubricating oil improvers on performance of crankshaft seals
PublikacjaThis paper presents an original method for checking influence of lubricating oil improvers on performance of crankshaft seals of combustion piston engine. Crankshaft seals were tested with the use of a modified friction node of T-02 four- ball apparatus in laboratory conditions. The tests were conducted according to a worked-out algorithm. Their results confirmed usefulness of the method for determining „harmful” performance...
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Using Rule-Based System for Monitoring Marine Navigation Data Processing
PublikacjaProcessing marine navigational data requires sophisticated software solutions. Typically, specialized tools called processors are analyzing raw data from different sensors. It becomes important to create the monitoring software that is able to validate and verify processing components integrated into the final system. Drools®business rule management platform provides a core business rules engine, web authoring and rules management...
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Modified dynamic time warping method applied to handwritten signature authenticity verification
PublikacjaA signature verification system based on static features and time-domain functions of signals obtained using a tablet has been presented in the paper. The signature verification method, based mainly on dynamic time warping coupled with some signature image features, has been described. The FRR measures reflecting the method’s efficiency have been evaluated for verification attempts performed directly after obtaining model signatures...
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A novel approach to energy safety improvement in the marine power plants with active power surge compensator
PublikacjaPaper raises a point of power surges and theirs adverse effects in the marine power plants. The article explains a source of surges appearance, and presents measurements carried out on a modern ship. It discusses effects of dynamic power transients on the ship’s energy safety. Finally it proposes, a novel approach for power surge elimination, based on medium voltage active conditioner. As well as it propose the topology and control...
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SUBJECTIVE PERCEPTION OF MUSIC GENRES IN THE FIELD OF MUSIC INFORMATION RETRIEVAL SYSTEMS
PublikacjaThe aim of this paper is to evaluate the relationship between perception of music genres and subjective features of music that can be assigned to them. For this purpose a group of subjective features such as loudness, melody, rhythm, volume, instrumentation was chosen to describe music genres. A group of 30 listeners with normal hearing, ranging from 20 to 40, was created. Each sub-ject participating in listening tests was asked...
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SUBJECTIVE PERCEPTION OF MUSIC GENRES IN THE FIELD OF MUSIC INFORMATION RETRIEVAL SYSTEMS
PublikacjaThe aim of this paper is to evaluate the relationship between perception of music genres and subjective features of music that can be assigned to them. For this purpose a group of subjective features such as loudness, melody, rhythm, volume, instrumentation was chosen to describe music genres. A group of 30 listeners with normal hearing, ranging from 20 to 40, was created. Each sub-ject participating in listening tests was asked...
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Hydrographic Multisensory Unmanned Watercraft
PublikacjaThis article describes the design of the unmanned surface vessel (USV) and the algorithms for planning the trajectories to be followed on measurement missions. The algorithms take account of the dynamically varying impacts of external forces (wind and surface current) on the vessel's motion. Feedback loops enable the counteraction of external factors that cause disturbance to the desired trajectory. The sensors installed on the...
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Monitoring of underdeck corrosion by using acoustic emission method
PublikacjaThis paper presents first short characteristics of underdeck corrosion process as well as a problem of its monitoring. Next is described an acoustic emission (AE) method elaborated by Department of Ship Technology , Quality Systems and Material Engineering, Gdańsk University of Technology in cooperation with partners of CORFAT project realized within 7th EU Frame Program . Further are presented short characteristics of the emission...
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Timber-frame house resistant to dynamic loads - analysis of wall panel filled with polyurethane foam
PublikacjaThe present study shows the experimentally and numerically determined response of a single timber-frame house wall panel filled with polyurethane (PU) foam under dynamic loads. The harmonic tests were conducted for the following frequencies: 0.5 Hz, 1.0 Hz, 2.0 Hz and 5.0 Hz for various values of the specified displacement. Based on the results of the comparison between the experimental tests and the numerical analyses, the numerical...
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Selected aspects of determining the reliability of the pump subsystems with redundancy, used in main engine auxiliary systems
PublikacjaThe rules of classification societies require the use of redundancy in the systems essential for the safety of the ship. Duplication of pumps in the main engine auxiliary systems like cooling water system, lubricating oil system, fuel oil system is a good example here. Therefore, in the author's opinion, some attention should be paid to this issue. Two important questions arise here. Does duplication of pumps in marine systems...
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Adaptive system for recognition of sounds indicating threats to security of people and property employing parallel processing of audio data streams
PublikacjaA system for recognition of threatening acoustic events employing parallel processing on a supercomputing cluster is featured. The methods for detection, parameterization and classication of acoustic events are introduced. The recognition engine is based onthreshold-based detection with adaptive threshold and Support Vector Machine classifcation. Spectral, temporal and mel-frequency descriptors are used as signal features. The...
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Selected Issues of Hybrid Outboard Motors
PublikacjaThe aim of the research reported in the article was designing a hybrid drive system based on an outboard internal combustion engine offered by a selected producer and testing its operating characteristics. The article presents different designs of this type of drive which can be found in the literature and are available in the market. The designed hybrid outboard drive system was tested both on the laboratory test rig and in real...
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Load Tests of the Movable Footbridge Over the Port Canal in Ustka
PublikacjaThe paper presents the acceptance tests carried out on the open footbridge over the port canal in the Port of Ustka. The steel footbridge construction is created by a single pylon to which a movable truss span is suspended with a theoretical span of 52.3 m. The studies about load test of the object included static and dynamic extortion and measurements. In static tests the ballast was of pallets with concrete blocks. Dynamic studies...
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Systematic Management of Simulation State for Multi-Branch Simulations in Simulink
PublikacjaSystematic simulation is a technique related and motivated by the formal analysis of hybrid dynamic systems. It combines the exhaustive and conservative nature of traditional model checking with numerical simulation for providing efficient algorithms to manage simulations. Multi-branch simulation is the concept advancing simulation efficiency by reducing the number of state transitions. This paper introduces an approach to implement...
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Static and dynamic concrete calculations: Breakable aggregates in DEM model
PublikacjaThe paper deals with the calculations of a 3-point bending beam under static and dynamic loads. The real microstructure was obtained from laboratory tests using micro-tomography images. The quasi-static results were compared directly with experimental data at both macro and micro levels. Subsequently, higher strain rates were applied to investigate dynamic effects. The study focused on the influence of dynamic loading on the macroscopic...
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Diagnostic testing of marine propulsion systems with internal combustion engines by means of vibration measurement and results analysis
PublikacjaIn this paper selected issues concerning vibration diagnosis of the mechanical system within marine propulsion units have been presented, carried out on the basis of experimental examinations of a real object in which an exceedance of the allowable vibration’s level had been observed. Used diagnosing system has been characterised. A procedure of longitudinal and transverse vibrations shaft lines of the mechanical system within...
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Modeling of low calorific gas burning in a deficient oxygen environment and high-temperature oxidizer
PublikacjaThe experimental research will be performed using the experimental facility with a combustion chamber. The oxygen concentration in combustion oxidizers will be varied from 21% by volume (normal) air to 2%. The test combustion chamber will be fed with propane or methane as the reference fuel, then with low calorific fuels as test gases obtained by mixing various combustible components, e.g. H2, CH4, CO, and neutral gases, e.g. N2,...
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Determination of total mercury in raw petrol using cold vapour atomic absorption spectrometry
PublikacjaPresence of different forms of mercury in petroleum based products may impair the proper operation of the equipment or led to poisoning of automotive catalysts. However much more important problem is environmental pollution with mercury emitted from different types of fossil fuels. Although the average mercury concentration in petroleum based products (automotive fuels) is on the level around 1 ppb, taking into account annual...
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Path planning algorithm for ship collisions avoidance in environment with changing strategy of dynamic obstacles
PublikacjaIn 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...
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SAMOCHÓD SPORTOWY DUOMOTO NAPĘDZANY DWOMA SILNIKAMI SPALINOWYMI
PublikacjaPrzedstawiono zaprojektowany i zbudowany przez zespół czterech dyplomantów Wydziału Mechanicznego Politechniki Gdańskiej samochód sportowy napędzany dwoma silnikami. Jeden z nich umieszczono z przodu pojazdu. Przekazuje on moment obrotowy na koła osi przedniej poprzez zespolony układ napędowy. Drugi silnik, usytuowany ztyłu pojazdu, w identyczny sposób przekazuje moment napędowy na koła osi tylnej....
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The statistical impact of experimental result scatter of asphalt mixtures on their numerical modelling
PublikacjaThe paper presents selected test results of asphalt mixture conducted in low temperatures. The obtained parameters are highly diverse. It concerns ultimate breaking loads, stiffness parameters related to Young's modulus but also the fracture course. Statistical analysis upon the results makes it possible to relevantly estimate the material-defining parameter values. Such a random approach leads to the mean values of breaking and...
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Inżynieria odwrotna bazy paliw płynnych w Gdańsku
PublikacjaArtykuł prezentuje prace z zakresu pozyskania danych o zbiornikach bazy paliw płynnych w Gdańsku. Przedstawione rozwiązanie nie ogranicza się tylko do stworzenia (rejestracji) chmury punktów, ale jest próbą wskazania użycia naziemnego skaningu laserowego do stworzenia bazy informacji o bazie paliw – w tym głównie geometrii zbiorników. Autorzy prezentują proces inwentaryzacji, rejestrację chmury punktów oraz wskazują zasady tworzenia...
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Dynamics analysis of footbridge mode shapes the s8 expressway on the basis of the results of in situ tests
PublikacjaNon-destructive diagnostics for structure may use dynamic measurements realized during vibrations of a facility induced by dynamic environmental impact, enforced by the use of inductors or impulse impact. Dynamic tests and the analysis were undertaken for a footbridge situated over the expressway S8. The studies in situ allowed for dynamic characteristics to be determined: frequency, shape modes and damping for respective frequency...
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Experimental research on water lubricated marine stern tube bearings in conditions of improper lubrication and cooling causing rapid bush wear
PublikacjaWater lubricated bearings are popular in sliding bearings of marine propeller shafts, turbines and pump shafts. Such popularity is partly due to their simple construction which also means a relatively affordable price. In practical experience one may also observe cases of rapid wear or even malfunctions of this bearings, some of which may be caused by insufficient flow of lubricant leading to overheating. The conducted...
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Self-Organization of Graft Copolymers and Retortable iPP-Based Nanoporous Films Thereof
PublikacjaPolyolefins might become inexpensive alternatives to the existing membranes based on polyethersulfone. Here we disclose the production of retortable, well-defined PP-based nanoporous membranes derived from amphiphilic graft copolymer precursors. The graft copolymers, containing a polypropylene backbone and polyester grafts, were obtained by grafting lactones, specifically δ-valerolactone and ε-caprolactone, from well-defined randomly...
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Ladder-Based Synthesis and Design of Low-Frequency Buffer-Based CMOS Filters
PublikacjaBuffer-based CMOS filters are maximally simplified circuits containing as few transistors as possible. Their applications, among others, include nano to micro watt biomedical sensors that process physiological signals of frequencies from 0.01 Hz to about 3 kHz. The order of a buffer-based filter is not greater than two. Hence, to obtain higher-order filters, a cascade of second-order filters is constructed. In this paper, a more...
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A method to assess transverse vibration energy of ship propeller shaft for diagnostic purposes
PublikacjaThe article discusses a key problem of ship propulsion system vibration diagnostics, which concerns assessing this part of mechanical energy transmitted from the main engine to the ship propeller which is dissipated due to propeller shaft vibration. A simplified calculation model is proposed which allows the total energy of the generated torsional vibration to be assessed from the shaft deflection amplitude measured at the mind-span...
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Fractographical quantitative analysis of EN-AW 2024 aluminum alloy after creep pre-strain and LCF loading
PublikacjaThis paper explores the applicability of a new damage parameter combining both fracture surface topography and loading features to estimate the fatigue lifetime under creep pre-strain and low-cycle fatigue loading. Fractures of EN-AW 2024 aluminum alloy caused by mixed creep and low-cycle fatigue loading are experimentally characterized and quantified via surface topography analysis. The specimens were preliminary damaged in a...
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Experimental determination of dynamic properties of cylindrical steel tank model filled with liquid
PublikacjaIn technical branches, such as chemical or petroleum industries, cylindrical steel tanks are essential structures used for storage of liquid products. Any failure might have disastrous consequences, therefore their safety and reliability is essential. The aim of the present paper is to show the results of the experimental study which has been conducted on a scaled model of a real tank used in Poland. The investigation was carried...
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The Impact of Material Selection on Durability of Exhaust Valve Faces of a Ship Engine – A Case Study
Publikacjawo alloys were used in order to extend the service life of marine engine exhaust valve head. Layers of cobalt base alloys were made of the powders with with chemical composition as follow: the layer marked L12; C-1,55%; Si-1,21%; Cr-29,7%; W-9%; Ni-2%; Mo<0,01%; Fe-1,7%; Co-54,83% and the layer marked N; C-1,45%; Co-38,9%; Cr-24,13%; Ni-10,43%; W-8,75%; Fe-7,64%; Mo-7,56%; Si-2,59%. Base metal was valve steel after heat treatment....
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Trophic Transfer of Mercury in a Temperate Marine Food Web, Southern Baltic Sea
PublikacjaMercury (Hg) is considered to be one of the most dangerous global environmental pollutants. The toxicity and bioavailabilityof Hg depend on its chemical form, and the greatest hazard is posed by the organomercurial compounds. Hg is introduced into the human body primarily through the consumption of fish and seafood. Despite numerous studies on Hg in marine organisms, there is still a gap in the knowledge on Hg uptake and...
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Evaluation of Low Temperature Properties of Rubberized Asphalt Mixtures
PublikacjaThe paper presents low-temperature test results of asphalt mixtures designed with use of bitumen modified by crumb rubber and also SBS polymer. Laboratory tests were conducted on two types of asphalt mixtures for wearing course – stone matrix asphalt (SMA 8) and porous asphalt (PA 8). This paper presents results of the following laboratory tests at low temperatures: TSRST test, three point bending creep test, fracture toughness...
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Evaluation of Six Degrees of Freedom 3D Audio Orchestra Recording and Playback using multi-point Ambisonic interpolation
PublikacjaThis paper describes a strategy for recording sound and enabling six-degrees-of-freedom playback, making use of multiple simultaneous and synchronized Higher Order Ambisonics (HOA) recordings. Such a strategy enables users to navigate in a simulated 3D space and listen to the six-degrees-of-freedom recordings from different perspectives. For the evaluation of the proposed approach, an Unreal Engine-based navigable 3D audiovisual...
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Analysing the potential for application of the phase shift method in endoscopic examination of marine engines
PublikacjaThe article presents theoretical principles of image processing in digital endoscopy which makes use of a miniaturised spectral scanner “PhaseProbe” designed by General Inspection Technologies LP, the producer of the measuring videoendoscope Everest XLG3. The technology of optoelectronic 3D mapping of the examined surface, which consists in measuring the phase shift between the emitted and reflected light waves, is briefly described....
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Adaptive dynamic control allocation for over-actuated dynamic positioning system based on backstepping method in case of thruster faults
PublikacjaThe objective of the research considered in this paper is dynamic positioning of a nonlinear over-actuated marine vessel in the presence of limited information about thruster forces. First, the adaptive backstepping method is used to estimate the input matrix which will compensate partial loss of actuator effectiveness in the presence of actuator dynamics. Then, the adaptive commanded virtual forces and moment are allocated into...
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Predicting seismic response of SMRFs founded on different soil types using machine learning techniques
PublikacjaPredicting the Maximum Interstory Drift Ratio (M-IDR) of Steel Moment-Resisting Frames (SMRFs) is a useful tool for designers to approximately evaluate the vulnerability of SMRFs. This study aims to explore supervised Machine Learning (ML) algorithms to build a surrogate prediction model for SMRFs to reduce the need for complex modeling. For this purpose, twenty well-known ML algorithms implemented in Python software are trained...
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Simulations of hydro-fracking in rock mass at meso-scale using fully coupled DEM/CFD approach
PublikacjaThe paper deals with two-dimensional (2D) numerical modelling of hydro-fracking (hydraulic fracturing) in rocks at the meso-scale. A numerical model was developed to characterize the properties of fluid-driven fractures in rocks by combining the discrete element method (DEM) with computational fluid dynamics (CFD). The mechanical behaviour of the rock matrix was simulated with DEM and the behaviour of the fracturing fluid flow...
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A handwritten signature verification method employing a tablet
PublikacjaA signature verification system based on static features and time-domain functions of signals obtained using a tablet has been presented in the paper. The signature verification method, based mainly on dynamic time warping coupled with some signature image features, has been described. The FRR measures reflecting the method's efficiency have been evaluated for verification attempts performed directly after obtaining model signatures...
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Technical State Assessment of Charge Exchange System of Self-Ignition Engine, Based On the Exhaust Gas Composition Testing
PublikacjaThis paper presents possible use of results of exhaust gas composition testing of self - ignition engine for technical state assessment of its charge exchange system under assumption that there is strong correlation between considered structure parameters and output signals in the form of concentration of toxic compounds (ZT) as well as unambiguous character of their changes. Concentration of the analyzed ZT may be hence considered...