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Wyniki wyszukiwania dla: VARIABLE KINEMATICS
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Modeling and optimization of chemical-treated torrefaction of wheat straw to improve energy density by response surface methodology
PublikacjaToday, torrefaction is important technique for extending the potential of biomass for improvement of energy density. The independent variables investigated for torrefaction study were temperature, retention time, acid concentration, and particle size. The experiment was designed by central composite design (CCD) method using design expert (version 11). The three dependent variables were higher heating value (HHV), energy enhancement...
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Linear viscoelastic transversely isotropic model based on the spectral decomposition of elasticity tensors
PublikacjaThe linear viscoelasticity is still a useful model in the engineering for studying the behavior of materials loaded with different loading rates (frequencies). Certain types of materials reveal also an anisotropic behavior: fiber reinforced composites, asphalt concrete mixtures, or wood, to name a few. In general, researchers try to identify experimentally the dependence of engineering constants like: directional Young’s moduli...
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How can systems thinking help us in the COVID‐19 crisis?
PublikacjaThe COVID-19 pandemic outbreak remains one of the most influential events in the global economy over the recent years. While being primarily public health related, it has a tremendous impact on many other aspects, including business management. Many businesses were forced to introduce rapid changes to their business models in order to survive. The aim of this paper is to show the complexity and interrelations of changes triggered...
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Prediction of energy consumption and evaluation of affecting factors in a full-scale WWTP using a machine learning approach
PublikacjaTreatment of municipal wastewater to meet the stringent effluent quality standards is an energy-intensive process and the main contributor to the costs of wastewater treatment plants (WWTPs). Analysis and prediction of energy consumption (EC) are essential in designing and operating sustainable energy-saving WWTPs. In this study, the effect of wastewater, hydraulic, and climate-based parameters on the daily consumption of EC by...
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IDENTIFICATION AND COMPARATIVE ANALYSIS OF FACTORS INFLUENCING ROAD SAFETY IN US REGIONS AND IN POLISH VOIVODESHIPS
PublikacjaAnalyses of road safety at national level have been run for many years and large number of publications concerning them appeared so far. How interdisciplinary the issue is, has been shown by literature studies done by the author of the paper. It appears that economists, mathematicians, doctors as well as engineers have studied the issue. It is not an easy one, as results of many analyses lead to conflicting conclusions and...
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Development of advanced machine learning for prognostic analysis of drying parameters for banana slices using indirect solar dryer
PublikacjaIn this study, eXtreme Gradient Boosting (XGBoost) and Light Gradient Boosting (LightGBM) algorithms were used to model-predict the drying characteristics of banana slices with an indirect solar drier. The relationships between independent variables (temperature, moisture, product type, water flow rate, and mass of product) and dependent variables (energy consumption and size reduction) were established. For energy consumption,...
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The Influence of Microstructure on the Passive Layer Chemistry and Corrosion Resistance for Some Titanium-Based Alloys
PublikacjaThe effect of microstructure and chemistry on the kinetics of passive layer growth and passivity breakdown of some Ti-based alloys, namely Ti-6Al-4V, Ti-6Al-7Nb and TC21 alloys, was studied. The rate of pitting corrosion was evaluated using cyclic polarization measurements. Chronoamperometry was applied to assess the passive layer growth kinetics and breakdown. Microstructure influence on the uniform corrosion rate of these alloys...
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Multi-pathway mechanism of polydopamine film formation at vertically aligned diamondised boron-doped carbon nanowalls
PublikacjaBoron-doped carbon nanowall (B:CNW) electrodes were used as a platform for studying the electropolymerisation of dopamine. Due to the unique properties of B:CNW, including the fast charge-transfer kinetics and high surface conductivity, a high degree of reversibility of redox reactions was achieved. Three separated redox peaks were observed on voltammograms and attributed to three fundamental reactions in the dopamine polymerisation...
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Anisotropic optical properties of few-layer black phosphorus coatings: from fundamental insights to opto-electrochemical sensor design
PublikacjaFew-layer black phosphorus (FLBP) is characterised by a tuneable bandgap, high carrier mobility and anisotropic optical properties. It therefore has the potential to find applications in electronics and photonics. FLBP oxidizes upon exposure to air, limiting its utility in devices and components. To address this issue, the thesis introduces methods and tools developed for studying FLBP's optical parameters, with a particular emphasis...
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Method of selective fading as a educational tool to study the behaviour of prestressed concrete elements under excess loading
PublikacjaPrestressed structures are a key to realization of the boldest architectural ideas, characteristic feature of prestressed structure is better use of concrete material properties by insertion of internal forces. Learning about pre-stressed reinforced concrete structures is an integral part of Graduate Studies Program in construction engineering. Know-how of geometry change patterns in prestressed concrete elements under certain...
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Thermal and technological aspects of double face grinding of C45 carbon steel
PublikacjaIn grinding, the contact zone temperature is a decisive factor influencing the achievable surface quality and the grinding tool wear. In contrast to other grinding processes, only few information regarding double face grinding with planetary kinematics when processing steel is known up to date. Since the successive substitution of in-dustrial double-sided lapping processes by double-sided grinding, it has become necessary to the...
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Czynniki wzrostu zatrudnienia w mikro przedsiębiorstwach – czy chcieć znaczy móc?
PublikacjaDotychczasowe badania nad wzrostem małych i średnich przedsiębiorstw, prowadzone od wielu lat zarówno na świecie jak i w Polsce nie przyniosły odpowiedzi na pytanie jakie czynniki na to zjawisko wpływają. W artykule przedstawiono pokrótce podejścia badawcze wykorzystywane w badaniu czynników wzrostu. W oparciu o przeprowadzone w 2009 i 2012 roku badania panelowe w Województwie Pomorskim, przeanalizowano wpływ czynników związanych...
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Die neue Straßenbrücke in Toruń (Thorn) – Teil 2 – Nachweise
PublikacjaAls Fortsetzung von Teil 1, der über den Entwurf und den Bau der neuen, die Weichsel querenden Straßenbrücken in Toruń (deutsch: Thorn) berichtet, geht es im Folgenden um die theoretischen und experimentalen Nachweisen zum Montageprozess und zu Probebelastungen. Somit eine umfassende Beurteilung der beschriebenen , herausragenden Ingenieursleistung gegeben.
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Bile Acids: Key Players in Inflammatory Bowel Diseases?
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SP-1, a Serine Protease from the Gut Microbiota, Influences Colitis and Drives Intestinal Dysbiosis in Mice
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Gut Serpinome: Emerging Evidence in IBD
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Sensorless Disturbance Detection for Five Phase Induction Motor with Third Harmonic Injection
PublikacjaThe paper presents a sensorless disturbance detection procedure that was done on a five phase induction motor with third harmonic injection. A test bench was developed where a three phase machine serves as disturbance generator of different frequencies. The control of the machines is based on multi scalar variables that ensures an independent control of the motor EMF and the rotor flux. For disturbance identification a speed observer...
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Reliability-Based Stability Analysis of a Baltic Cliff by the Combined Response Surface Method
PublikacjaA simple, straightforward computational procedure was proposed, incorporating the Response Surface Method (RSM) linked with the standard Monte Carlo (MC) simulation method and the Point Estimate Method (PEM). PEM samples make it possible to analyse the sensitivity of the cliff’s stability to variation in subsoil parameters and to reduce the number of random variables of the problem. The proposed methods were tested in two cases:...
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Wykorzystanie Web 2.0 oraz architektury informacji w pracy brokera informacji = TAKING ADVANTAGE OF WEB 2.0 AND THE INFORMATION ARCHITECTURE IN THE INFORMATION BROKER’S WORK
PublikacjaThe development of information and communication technologies, dissemination of access as well as unlimited increase of publications result in the uncontrolled growth of knowledge resources. Looking up for the relevant information becomes increasingly difficult, especially when time plays a role. Such process requires vast knowledge, practical experience in obtaining and providing information and also analytical...
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Mechanical behaviour of the implant used in human hernia repair under physiological loads
PublikacjaIn laparoscopic operations of abdominal hernias some recurrences still take place, even when applying a surgical mesh. This is usually caused by a failure of the connection between the tissue and the implant. The study deals with the influence of an implant’s orientation on forces in joints, which connect the mesh to human tissues. In the paper, the implant is modelled as a membrane structure within framework of the Finite Element...
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Methodology for Performing Bathymetric Measurements of Shallow Waterbodies Using an UAV, and their Processing Based on the SVR Algorithm
PublikacjaState-of-art methods of bathymetric measurements for shallow waterbodies use Global Navigation Satellite System (GNSS) receiver, bathymetric Light Detection and Ranging (LiDAR) sensor or satellite imagery. Currently, photogrammetric methods with the application of Unmanned Aerial Vehicles (UAV) are gathering great importance. This publication aims to present step-by-step methodology for carrying out the bathymetric measurements...
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Methodology for Performing Bathymetric Measurements of Shallow Waterbodies Using an UAV, and their Processing Based on the SVR Algorithm
PublikacjaState-of-art methods of bathymetric measurements for shallow waterbodies use Global Navigation Satellite System (GNSS) receiver, bathymetric Light Detection and Ranging (LiDAR) sensor or satellite imagery. Currently, photogrammetric methods with the application of Unmanned Aerial Vehicles (UAV) are gathering great importance. This publication aims to present step-by-step methodology for carrying out the bathymetric measurements...
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Diagnostics of the tram track shape with the use of the global positioning satellite systems (GPS/Glonass) measurements with a 20 Hz frequency sampling
PublikacjaSatellite geodetic measurements used in the diagnosis of railway tracks require professional receivers and a very high frequency rate of data processing. It stems from a significant speed (10 km/h) kinematic measurements carried out during the passage of a measuring platform. The survey results (positions) of deformed railroad track have waveforms nature requiring additional processing methods and approximations. Due to the announcement...
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Optymalizacja efektywności hamowania odzyskowego w transporcie szynowym przez sterowanie czasem przyjazdu na stację
PublikacjaArtykuł nawiązuje do poprzednich prac autorów, w których przedstawiono model organizacji ruchu kooperujących pociągów z uwzględnieniem optymalizacji wykorzystania energii zwracanej do sieci jezdnej. W przedstawionej pracy zmodyfikowano model zmieniając główną zmienną sterującą, mającą wpływ na efektywne wykorzystanie energii, z czasu odjazdu na czas przyjazdu pociągu na stację lub przystanek. Optymalizacja dokonywana jest przez...
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Approximation of Fractional Order Dynamic Systems Using Elman, GRU and LSTM Neural Networks
PublikacjaIn the paper, authors explore the possibility of using the recurrent neural networks (RNN) - Elman, GRU and LSTM - for an approximation of the solution of the fractional-orders differential equations. The RNN network parameters are estimated via optimisation with the second order L-BFGS algorithm. It is done based on data from four systems: simple first and second fractional order LTI systems, a system of fractional-order point...
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Image as a key factor of brand value at social media
PublikacjaThe paper aims to investigate the relationship between social media presence and activities and brand value for the most valuable Global Brands 2012 (Interbrandt 2013). Social media communication is an innovative way of communication. Brand value is a key performance indicator of brand strategy for managers. Brand and category image realized to be the key factor of investigated relation.
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Determiantion of optimal conditions for the isolation of oil from the fishing industry offal
PublikacjaFish processing generates significant amounts of offal, which usually is converted into fodder meal or is stored into landfills. However, some part of this offal could serve as a source of valuable products, such as fish oil, collagen or gelatin. the aim of the study was to determine the conditions of oil isolation from salmon skins ensuring high yield and quality of the product.
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Probabilistic sensitivity of the limit states of structures using Monte Carlom simulation
PublikacjaThe paper presents the concept of probabilistic sensitivity of structural limit states with respect to given design variables. A general idea is presented, illustrated by a simple case solved in an analytical way. More general approach is presented for the engineering structures, in this case a dedicated Monte Carlo simulation procedure is involved as part of the methodology. Illustration of the engineering case is done, by means...
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Simplified probabilistic analysis of settlement of cyclically loaded soil stratum using point estimate method
PublikacjaThe paper deals with the probabilistic analysis of settlement of a non-cohesive soil layer subjected to cyclic loading. Originally, the settlement assessment is based on deterministic compaction model which requires integration of a set of differential equations. However, making use of the Bessel functions the settlement of the soil stratum can be calculated by means of simplified algorithm. The compaction model parameters were...
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Subsoil degradation effect in reliability analysis of the jack-up platform structure
PublikacjaStructural reliability analysis is considered, by FORM and SORM applied to a certain idealized soil-platform structure interaction problem due to cyclic water wave and wind loads. Wave and wind loads are random variables, whereas dead load is deterministic. Load parameters are typical for storm conditions in the Baltic Sea. The soil-structure interaction is idealized as a set of linear translational and rotational springs. Due...
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Pre-selection and assessment of green organic solvents by clustering chemometric tools
PublikacjaThe study presents the result of the application of chemometric tools for selection of physicochemical parameters of solvents for predicting missing variables – bioconcentration factors, water-octanol and octanol-air partitioning constants. EPI Suite software was successfully applied to predict missing values for solvents commonly considered as “green”. Values for logBCF, logKOW and logKOA were modelled for 43 rather nonpolar solvents...
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Simultaneous grouping and ranking with combination of SOM and TOPSIS for selection of preferable analytical procedure for furan determination in food
PublikacjaNovel methodology for grouping and ranking with application of self-organizing maps and multicriteria decision analysis is presented. The dataset consists of 22 objects that are analytical procedures applied to furan determination in food samples. They are described by 10 variables, referred to their analytical performance, environmental and economic aspects. Multivariate statistics analysis allows to limit the amount of input...
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TS-based RSM-aided design of cold-formed steel stiffened C-sectional columns susceptible to buckling
PublikacjaThe paper focuses on joint-performance analysis of a built-up cold-formed thin-walled C-sectional column with a fillister (stiffener) of the same type, interconnected with a series of bolts located along the length of the compressed members in specific spacing. The quantity of bolts and the non-connected starting distance of the fillister are considered random variables of the problem. Optimal distribution of joints on the stiffener...
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Open-Phase Fault Detection Method for Sensorless Five-Phase Induction Motor Drives with an Inverter Output Filter
PublikacjaThe paper presents the sensorless five-phase induction motor drive implementation with an inverter output filter with third harmonic injection. For the sensorless operation, the required observers are presented for the first and third harmonics with consideration of the inverter output filter. Moreover, the interaction of the observers and the control system is capable to handle a deactivation of one or two phases, which improves...
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EFFICIENCY OF HEALTHCARE SYSTEMS IN EUROPEAN COUNTRIES - THE DEA NETWORK APPROACH
PublikacjaHealthcare systems in Europe are constantly undergoing reforms which adapt them to social, economic and political requirements. The aim of this article is to examine the efficiency of healthcare systems in 30 European countries in 2014. The Network Data Envelopment Analysis (NDEA) model was used. The efficiency of the countries’ overall health systems and their two main components were examined: the public health system and the...
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Modified SPWM Technique with Zero-Sequence Voltage Injection for a Five-Phase, Three-Level NPC Inverter
PublikacjaThis article presents a modified sinusoidal pulse-width modulation (SPWM) scheme for a five-phase, three-level neutral-point-clamped inverter. The modulation scheme deploys a modified min–max function to inject the zero-sequence components into the reference modulating signals; hence enabling the effective utilization of the DC-link voltage. Balanced split-input DC-link voltages were achieved through further incorporation of adjustable...
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TOWARD A FUZZY MODEL OF POLISH INTERNET MORTGAGE MARKET
PublikacjaThis article presents our continuing efforts to develop a model of the Internet-based mortgage market in Poland. It sums up modeling research done over the last 4 years, also showing the stages and the process of building and verifying the proposed model consisting of three submodels. The submodels are described for three market situations; that is, a stable market, financial crisis, and economic boom. The proposed model variables...
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“Project-factor-decision”. Decisive factors in IT projects and their impact on its success
PublikacjaThe aim of this article is to indicate the need for a deepening, systematizing and codifying of the theoretical and practical knowledge on IT project management, in the area of management decision-making processes. The scope of decisions made by managers is constantly on the increase. Project managers make decisions not only within the classic triangle of constraints, which consists of a schedule, a budget and the project scope,...
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Processing of point cloud data retrieved from terrestrial laser scanning for structural modeling by Finite Element Method
PublikacjaFinite Element Method is one most popular contemporary method of strength analysis. The method is an advanced method for solving differential equations, based on discretization, which means that area is divided into finite elements. Each finite element has a solution of the equation approximated by specific functions and performing the actual calculations only for nodes of this division. Finite Element Method is widely used in...
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IDENTIFICATION OF THE INTERFECE OF LATERAL SLIDE BEARINGS
PublikacjaIn the paper, the model of slide bearings of motor engine, the metodology of research on this type of bearings and its results are presented measurement standpoint consisting of main elements of Briggs & Stratton 550 serie 10 T 802 model piston motor engine driven by three phase elektric engine is introduced . On the measurement standpoint are measurements were done, needed for specification...
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Information System for Drivers Within the Integrated Traffic Management System - TRISTAR
PublikacjaAdvanced traveler information systems (ATIS) for drivers are a very important element of modern traffic management. In recent years ITS infrastructure is being developed also in Poland. It allows for delivering to drivers information related to the conditions in the road network through, inter alia, dedicated Variable Message Signs (VMS). Such information enables drivers to take decisions, contributing to improving the efficiency...
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Novel structure and design of compact UWB slot antenna
PublikacjaIn this paper, a novel structure of a compact UWB slot antenna is presented along with a simulation-driven design optimization algorithm for adjusting geometry parameters of the device. Our primary objective is to obtain small footprint of the structure while maintaining its acceptable electrical performance. It is achieved by introducing sufficiently large number of geometry degrees of freedom, including increased number of parameterized...
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A structure and simulation-driven design of compact CPW-fed UWB antenna
PublikacjaIn this letter, a structure of a miniaturized ultra-wideband CPW-fed antenna and its design proce-dure are presented. The antenna is a modified version of the design previously proposed in the literature, with additional degrees of freedom introduced in order to improve the structure flexibility. The small size is achieved by executing a rigorous optimization procedure that consists of two stages: (i) smart random search carried...
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Compensation of pressure peaks in pwk-type hydraulic pumps
Publikacjahydraulic axial pumps equipped with cam-driven commutation unit (pwk pumps) proved their high efficiency up to 55 mpa and ability to work self-sucking, even at high speed. displacement of pwk pump may easily be changed by moving its control cam. full discharge from hydrostatic forces makes such control possible by direct action of a low-energy actuator like proportional electromagnet or stepping motor. that eliminates heavy and...
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Evaluation of the impact of geometry and plastic deformation on the stray magnetic field around the bone shaped sample
PublikacjaInfluence of two factors: the variable cross-section and the localized plastic deformation, which affect the stray magnetic field profile of a ferromagnetic sample have been studied. Evaluation of an effect size is based on the analysis of the stray magnetic field component which is tangential to the longest dimension of a sample. However, in order to describe the nature of the stray magnetic field, the normal component (perpendicular...
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Water-mediated long-range interactions between the internal vibrations of remote proteins
PublikacjaIt is generally acknowledged that the mobility of protein atoms and the mobility of water molecules in the solvation layer are connected. In this article, we answer the question whether a similar interdependence exists between the motions of atoms of proteins separated by the hydration layers of variable thickness. The system consisted of a kinesin catalytic domain and a tubulin dimer. It was studied using molecular dynamics simulations....
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Strain sequence effect on fatigue life and fracture surface topography of 7075-T651 aluminium alloy
PublikacjaThe paper studies the effect of strain-loading sequence on fatigue lifetime and fracture surface topographies in 7075-T651 aluminum alloy specimens. Fatigue tests were performed in two ways: (i) constant-amplitude loading and (ii) two series of variable amplitude loading with non-zero mean strain values. The topography of the fatigue fractures was measured over their entire surfaces with the help of an optical confocal measurement...
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THE INTERACTION BETWEEN STEEL COLUMN CHORD AND CLOSELY SPACED REINFORCEMENT.
PublikacjaNowadays, more often than before, civil engineering designers are willing to use steel build-up members composed of single or doubled cold-formed chords interconnected using different mechanical connectors. This paper subject is an analysis of cooperation of a closely spaced built-up cold-formed chord interconnected with series of bolts that are located along the length of the member in a specific spacing. This distance along the...
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Architectural education and digital tools: the challenges and opportunities
PublikacjaEnriching architectural education with digital tools is the subject of this article. Such tools can create, support and visualise architecture. The focus in this article is on an interdisciplinary approach to media architecture (allowing variable visual content of architectural objects) and interactivity (user-space communication), revealing new possibilities in terms of human perception. The results of a survey on media architecture...
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Optimization of the efficiency of braking energy recovery in rail transport by changing arrival time
PublikacjaThe article refers to the previous work of the authors, in which the model of traffic organization of cooperating trains including the optimization of the use of energy returned to the catenary was presented. In the presented article, the model was modified by changing the main control variable, which affects the efficient use of energy. Departure time was changed for the arrival time of the train to the stop or station. The optimization...