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Search results for: RATIONAL EXTERIOR SPACE
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Using wavelet techniques for multibeam sonar bathymetry data compression
PublicationMultibeam sonars are widely used in applications like high resolution bathymetry measurements or underwater object imaging. One of the significant problems in multibeam sensing of the marine environment is large amount of data which must be transmitted from the sonar processing unit to an operator station using a limited bit rate channel. For instance, such a situation would be in the case when the multibeam sonar was mounted on...
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On the compression of multibeam sonar raw bathymetry data
PublicationMultibeam sonars are widely used in applications like high resolution bathymetry measurements or underwater object imaging. One of the significant problems in multibeam sensing of the marine environment is large amount of data which must be transmitted from the sonar processing unit to an operator station using a limited bit rate channel. For instance, such a situation would be in the case when the multibeam sonar was mounted on...
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Time-domain description of point-source acoustic wavefields as a useful approach in ultrasonic techniques
PublicationIn traditional acoustics, field problems are usually treated in the frequency domain, broadband fields being reduced to superposition of harmonic spectrum components. However, this approach is inherently acausal and it is known that in case of arbitrary signals, the distribution-based, time-domain description can be more effective. The present paper is an attempt to expand the time-domain linear systems formalism onto space problems...
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Implementing a CSR Strategy in a Small Enterprise - a Case Study
PublicationAs a result of employees’ meetings conducted according to Kaizen workshops formula and seeking new development directions for the company (including CSR actions) various product and service innovations have been implemented. Also a market niche has been discovered, and as a consequence the company gained another profitable aspect of the business activity. The atmosphere and contribution in performing tasks have improved among...
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Finding the Right Solvent: A Novel Screening Protocol for Identifying Environmentally Friendly and Cost-Effective Options for Benzenesulfonamide
PublicationThis study investigated the solubility of benzenesulfonamide (BSA) as a model compound using experimental and computational methods. New experimental solubility data were collected in the solvents DMSO, DMF, 4FM, and their binary mixtures with water. The predictive model was constructed based on the best-performing regression models trained on available experimental data, and their hyperparameters were optimized using a newly...
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Studia podyplomowe dla nauczycieli przez Internet na przykładzie Gdańska i Warszawy
PublicationW artykule przedstawiono studia podyplomowe dla nauczycieli przez Internet realizowane przez Politechnikę Gdańską w ramach współpracy Wydziału Elektroniki, Telekomunikacji i Informatyki oraz Centrum Edukacji Niestacjonarnej. Zaproponowano model kształcenia zintegrowanego, który pozwala na lepsze wykorzystanie materiałów pomocniczych (biblioteki zasobów, linki, testy kontrolne, przykładowe prace dyplomowe z lat poprzednich) oraz...
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Time-Domain Description of Point-Source Acoustic Wavefields as a Useful Approach in Ultrasonic Techniques
PublicationIn traditional acoustics, field problems are usually treated in the frequency domain, broadband fields being reduced to superposition of harmonic spectrum components. However, this approach is inherently acausal and it is known that in case of arbitrary signals, the distribution-based, time-domain description can be more effective. The present paper is an attempt to expand the time-domain linear systems formalism onto space problems...
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Distributed Representations Based on Geometric Algebra: the Continuous Model
PublicationAuthors revise the concept of a distributed representation of data as well as two previously developed models: Holographic Reduced Representation (HRR) and Binary Spatter Codes (BSC). A Geometric Analogue (GAc - ''c'' stands for continuous as opposed to its discrete version) of HRR is introduced - it employs role-filler binding based on geometric products. Atomic objects are real-valued vectors in n-dimensional Euclidean space...
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Revitalization of Sopot - The Seaside Spa Town in Poland
PublicationSopot is a Polish seaside resort. In the past - as early as at the beginning of the 20th century - this town was famous for the healing opportunities they created: good conditions for resting and recreation. This town was places where everyone with enough selfesteem was willing to be seen. Since the post-war reconstruction until 1989 (establishment of local governments in Poland), not much has happened in Polish cities in terms...
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Synthesis and properties of AxV2Al20 (A = Th, U, Np, Pu) ternary actinide aluminides
PublicationPolycrystalline samples of AxV2Al20 (A = Ce, Th, U, Np, Pu; 0.7 ≤ x ≤ 1.0) actinide intermetallics were synthesized using the arc-melting method. Crystal structure studies were performed by means of powder x-ray diffraction and the Rietveld refinement method. All studied compounds crystallize in the CeCr2Al20-type structure (space group Fd-3m, no. 227) with the actinoid and Ce atom located in the oversized icosahedral cage formed...
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Reliable routing and resource allocation scheme for hybrid RF/FSO networks
PublicationSignificant success of wireless networks in the last decade has changed the paradigms of communication networks design. In particular, the growing interest in wireless mesh networks (WMNs) is observed. WMNs offer an attractive alternative to conventional cable infrastructures, especially in urban areas, where the cost of new installations is almost prohibitive. Unfortunately, the performance of WMNs is often limited by the cluttered...
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Unusual behaviour of (Np,Pu)B2C
PublicationTwo transuranium metal boron carbides, NpB2C and PuB2C have been synthesized by argon arc melting. The crystal structures of the {Np,Pu}B2C compounds were determined from single-crystal X-ray data to be isotypic with the ThB2C-type (space group R3m, a = 0.6532(2) nm; c = 1.0769(3) nm for NpB2C and a = 0.6509(2) nm; c = 1.0818(3) nm for PuB2C; Z = 9). Physical properties have been derived from polycrystalline bulk material in the...
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Reduced-Cost Constrained Modeling of Microwave and Antenna Components: Recent Advances
PublicationElectromagnetic (EM) simulation models are ubiquitous in the design of microwave and antenna components. EM analysis is reliable but CPU intensive. In particular, multiple simulations entailed by parametric optimization or uncertainty quantification may considerably slow down the design processes. In order to address this problem, it is possible to employ fast metamodels. Here, the popular solution approaches are approximation...
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EM‐driven constrained miniaturization of antennas using adaptive in‐band reflection acceptance threshold
PublicationNumerical optimization of geometry parameters is a critical stage of the design process of compact antennas. It is also challenging because size reduction is constrained by the necessity of fulfilling imposed electrical performance requirements. Furthermore, full‐wave electromagnetic (EM) analysis needs to be used for reliable performance evaluation of the antenna structure, which is computationally expensive. In this paper, an...
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Quasi-Global Optimization of Antenna Structures Using Principal Components and Affine Subspace-Spanned Surrogates
PublicationParametric optimization is a mandatory step in the design of contemporary antenna structures. Conceptual development can only provide rough initial designs that have to be further tuned, often extensively. Given the topological complexity of modern antennas, the design closure necessarily involves full-wave electromagnetic (EM) simulations and—in many cases—global search procedures. Both factors make antenna optimization a computationally...
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Numerical Solution of the Two-Dimensional Richards Equation Using Alternate Splitting Methods for Dimensional Decomposition
PublicationResearch on seepage flow in the vadose zone has largely been driven by engineering and environmental problems affecting many fields of geotechnics, hydrology, and agricultural science. Mathematical modeling of the subsurface flow under unsaturated conditions is an essential part of water resource management and planning. In order to determine such subsurface flow, the two-dimensional (2D) Richards equation can be used. However,...
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Context-Aware Indexing and Retrieval for Cognitive Systems Using SOEKS and DDNA
PublicationVisual content searching, browsing and retrieval tools have been a focus area of interest as they are required by systems from many different domains. Context-based, Content-Based, and Semantic-based are different approaches utilized for indexing/retrieving, but have their drawbacks when applied to systems that aim to mimic the human capabilities. Such systems, also known as Cognitive Systems, are still limited in terms of processing...
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Determination of Thermophysical Parameters Involved in The Numerical Model to Predict the Temperature Field of Cast-In-Place Concrete Bridge Deck
PublicationThe paper dealswith a concept of a practical computationmethod to simulate the temperature distribution in an extradosed bridge deck. The main goal of the study is to develop a feasible model of hardening of concrete consistent with in-situ measurement capabilities. The presented investigations include laboratory tests of high performance concrete, measurements of temperature evolution in the bridge deck and above all, numerical...
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Recycled Polyethylene terephthalate (PET) as Construction Material in Civil Engineering: A Review
PublicationIn general, the quantity of plastics of all types consumed annually all over the world has been growing in a phenomenal way. The manufacturing processes, service industries and municipal solid wastes (MSW) generate numerous waste plastic materials. The increasing awareness about the environment has tremendously contributed to the concerns related with disposal of the generated wastes. It is believed that the management of solid...
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Path-based methods on categorical structures for conceptual representation of wikipedia articles
PublicationMachine learning algorithms applied to text categorization mostly employ the Bag of Words (BoW) representation to describe the content of the documents. This method has been successfully used in many applications, but it is known to have several limitations. One way of improving text representation is usage of Wikipedia as the lexical knowledge base – an approach that has already shown promising results in many research studies....
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Asynchronous Charge Carrier Injection in Perovskite Light-Emitting Transistors
PublicationUnbalanced mobility and injection of charge carriers in metal-halide perovskite light-emitting devices pose severe limitations to the efficiency and response time of the electroluminescence. Modulation of gate bias in methylammonium lead iodide light-emitting transistors has proven effective in increasing the brightness of light emission up to MHz frequencies. In this work, a new approach is developed to improve charge carrier...
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Floodsar: Automatic mapping of river flooding extent from multitemporal SAR imagery
PublicationFloodsar is an open-source tool for automatic mapping of the flood extent from a time series of synthetic aperture radar (SAR) imagery. Floodsar is unsupervised, however, it requires defining the parameters search space, geographical area of interest, and some river gauge observations (e.g. water levels or discharges) time series that overlap temporarily with the SAR imagery. Applications of Floodsar are mainly in real-time monitoring...
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Secure Quaternion Feistel Cipher for DICOM Images
PublicationAn improved and extended version of a quaternion-based lossless encryption technique for digital image and communication on medicine (DICOM) images is proposed. We highlight and address several security flaws present in the previous version of the algorithm originally proposed by Dzwonkowski et al. (2015). The newly proposed secure quater- nion Feistel cipher (S-QFC) algorithm...
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An Empirical Propagation Model for Corridors in Office Buildings
PublicationThis paper presents an empirical propagation path loss model for corridors in office buildings. The proposed model estimates changeable character of radio signal attenuation, based on a special approach as a combination of the simple free-space model with the author’s model. The measurement stand and measurement scenario are described. The propagation path loss research have been made in corridor for different frequencies in range...
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Determinants of SME location in a suburban area: Evidence from the Gdańsk–Gdynia–Sopot metropolitan area.
PublicationGiven the importance of small and medium enterprises (SMEs) in the European economy, it is essential to have adequate information about the various factors that determine their choice of location. However, the size of a company is often an aspect not covered in theoretical studies and empirical research on industrial locations and urban planning. This article examines the place of residence...
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Carsharing - Opportunities and Threats for Cities: Proposals of Solutions for Urban Policy
PublicationThe carsharing of a current generation is a short-term car renting service with a capability to find in the nearest surrounding a fleet car parked anywhere in the public space where the previous user left it, as well as to book, open, rent and pay of, with the use of a dedicated mobile application. Nowadays, only a minority of municipalities is considering implementing the carsharing in their policies. The lack of awareness of...
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Compact global association based adaptive routing framework for personnel behavior understanding
PublicationPersonnel behavior understanding under complex scenarios is a challenging task for computer vision. This paper proposes a novel Compact model, which we refer to as CGARPN that incorporates with Global Association relevance and Adaptive Routing Pose estimation Network. Our framework firstly introduces CGAN backbone to facilitate the feature representation by compressing the kernel parameter space compared with typical algorithms,...
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Optimizing FSO networks resilient to adverse weather conditions by means of enhanced uncertainty sets
PublicationThis work deals with dimensioning of wireless mesh networks (WMN) composed of FSO (free space optics) links. Although FSO links realize broadband transmission at low cost, their drawback is sensitivity to adverse weather conditions causing transmission degradation on multiple links. Hence, designing such FSO networks requires an optimization model to find the cheapest configuration of link capacities that will be able to carry...
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Chip suction system in circular sawing machine: empirical research and computational fluid dynamics numerical simulations
PublicationThe experimental analysis of the wood chip removing system during its redesigning in the existing sliding table circular saw and computational fluid dynamic (CFD) numerical simulations of the air flow process is presented in the paper. The attention was focused on the extraction hood and the bottom shelter of the actual existing system. The main aim was to perform experimental research on the pressure distribution inside the...
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Modeling an Industrial Revolution: How to Manage Large-Scale, Complex IoT Ecosystems?
PublicationAdvancements around the modern digital industry gave birth to a number of closely interrelated concepts: in the age of the Internet of Things (IoT), System of Systems (SoS), Cyber-Physical Systems (CPS), Digital Twins and the fourth industrial revolution, everything revolves around the issue of designing well-understood, sound and secure complex systems while providing maximum flexibility, autonomy and dynamics. The aim of the...
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Mild poikilocapnic hypoxia increases very low frequency haemoglobin oxygenation oscillations in prefrontal cortex
PublicationBackground: The aim of the study was to investigate the effect of mild cerebral hypoxia on haemoglobin oxygenation(HbO2), cerebrospinal fluid dynamics and cardiovascular physiology. To achieve this goal, four signals were recorded simultaneously: blood pressure, heart rate / electrocardiogram, HbO2 from right hemisphere and changes of subarachnoid space (SAS) width from left hemisphere. Signals were registered from 30 healthy,...
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The Corporate Museum: A New Type of Museum Created as a Component of Marketing Company
PublicationA new type of museum appeared – the corporate museum. The museum institution in this instance has been used as a new marketing device for building corporate identity strategies. Their inception is not based on the existing context of a place, but appears to be integrated with the corporate identity program, exposing the company’s values and philosophy. The corporate museums are thematic, commercial buildings, owned by a particular...
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THE RESEARCH ON EGNOS SYSTEM IN CONTEXT OF THE ABILITY TO DETERMINE THE SHIP’S HULL SPATIAL ORIENTATION
PublicationThe European Geostationary Navigation Overlay Service (EGNOS) thanks to geostationary satellites covers an area of whole Europe, including Baltic and North Sea. It allows to fix the coordinates of object position with typical absolute accuracy of 1,5 m. Previous research have shown that relative accuracy is usually higher than absolute one [Nowak A., 2010, Nowak A., 2011], so probably it could be possible to use EGNOS to determine...
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Rapid Microwave Design Optimization in Frequency Domain Using Adaptive Response Scaling
PublicationIn this paper, a novel methodology for cost-efficient microwave design optimization in the frequency domain is proposed. Our technique, referred to as adaptive response scaling (ARS), has been developed for constructing a fast replacement model (surrogate) of the high-fidelity electromagnetic-simulated model of the microwave structure under design using its equivalent circuit (low-fidelity model). The basic principle of ARS is...
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Accurate simulation-driven modeling and design optimization of compact microwave structures
PublicationCost efficient design optimization of microwave structures requires availability of fast yet reliable replacement models so that multiple evaluations of the structure at hand can be executed in reasonable timeframe. Direct utilization of full-wave electromagnetic (EM) simulations is often prohibitive. On the other hand, accurate data-driven modeling normally requires a very large number of training points and it is virtually infeasible...
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A benchmark for particle shape dependence
PublicationParticle shape is a major parameter for the space-filling and strength properties of granular materials. For a systematic investigation of shape effect, a numerical benchmark test was set up within a collaborative group using different numerical methods and particles of various shape characteristics such as elongation, angularity and nonconvexity. Extensive 2D shear simulations were performed in this framework and the shear strength...
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The influence of the place of residence on the behavior and transport preferences of the inhabitants of the agglomeration
PublicationTransport behaviors and preferences have an impact on modal split, which is why they should form the basis for shaping the public transport offer. Achieving the goals of sustainable mobility requires taking into account differences in transport behavior and preferences characterizing residents from different areas of the agglomeration. Analyzing differences in behaviors and preferences, the possibilities and limitations resulting...
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Geoscience Methods in Real Estate Market Analyses Subjectivity Decrease
PublicationReal estate management, including real estate market analysis, is part of a so-called geosystem. In recent years, the popularity of creating various types of systems and automatic solutions in real estate management, including those related to property classification and valuation, has been growing in the world, mainly to reduce the impact of human subjectivity, to increase the scope of analyses and reduce research time. A very...
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Efficient Gradient-Based Algorithm with Numerical Derivatives for Expedited Optimization of Multi-Parameter Miniaturized Impedance Matching Transformers
PublicationFull-wave electromagnetic (EM) simulation tools have become ubiquitous in the design of microwave components. In some cases, e.g., miniaturized microstrip components, EM analysis is mandatory due to considera¬ble cross-coupling effects that cannot be accounted for otherwise (e.g., by means of equivalent circuits). These effects are particularly pronounced in the structures in¬volving slow-wave compact cells and their numerical...
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Ternary Bismuthide SrPtBi2: Computation and Experiment in Synergism to Explore Solid-State Materials
PublicationA combination of theoretical calculation and the experimental synthesis to explore the new ternary compound is demonstrated in the Sr–Pt–Bi system. Because Pt–Bi is considered as a new critical charge-transfer pair for superconductivity, it inspired us to investigate the Sr–Pt–Bi system. With a thorough calculation of all the known stable/metastable compounds in the Sr–Pt–Bi system and crystal structure predictions, the thermodynamic...
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Structured deformation of granular material in the state of active earth pressure
PublicationThe paper focuses on the ability of granular materials to undergo structured deformation by analysing the data from the retaining wall model tests and discrete element simulations. The structured deformation means the movement of a granular material which produces a stable, regular pattern of multiple shear bands. The paper's primary purpose is to study this kind of deformation for the selected data representing the state of active...
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Increasing the Utilization of dc-link Voltage of a Five-Leg VSI Based on Rotor Angle Control of Dual Induction Motors
PublicationThis paper introduces an increased utilization of the dc-link voltage of a five-leg voltage source inverter (VSI) based on the rotor flux angle control technique for dual induction motors, IM. The main purpose is to utilize additional abilities provided by a multi-motor drive system in limited operating conditions. Generally, a multi-motor drive system is widely used in electric vehicles (EVs), traction systems and in several industrial...
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Light formed through urban morphology and different organism groups: First findings from a systematic review
PublicationThe prevailing implementation and usage of contemporary lighting technologies and design practices in cities have created over-illuminated built environments. Recent studies indicate that exposure to electric lighting effects formed through spatial characteristics has visual, physiological, and behavioural effects on both humans and non-humans, such as wildlife. In order to gain a better understanding of the impact that electric...
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Social media and efficient computer infrastructure in smart city
PublicationSocial media require an efficient infrastructures of computer and communication systems to support a smart city. In a big city, there are several crucial dilemmas with a home and public space planning, a growing population, a global warming, carbon emissions, a lack of key resources like water and energy, and a traffic congestion. In a smart city, we expect an efficient and sustainable transportation, efficient management of resources...
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Particle shape dependence in 2D granular media
PublicationParticle shape is a key to the space-filling and strength properties of granular matter. We consider a shape parameter eta describing the degree of distortion from a perfectly spherical shape. Encompassing most specific shape characteristics such as elongation, angularity and non-convexity, eta is a low-order but generic parameter that we used in a numerical benchmark test for a systematic investigation of shape dependence in sheared...
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Car-sharing: The Impact on Metropolitan Spatial Structures
PublicationMany examples from the past show that new technologies designed to solve particular problems can also create side effects generating new problems. Some unforeseen or unwanted results may influence space use and spatial structures. Car-sharing is an invention to compete with car ownership. It drastically rise efficiency of car use, reducing the number of vehicles per users. Diffusion of car-sharing is going to accelerate in the...
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Low-Dimensional Magnetic Semimetal Cr0.65Al1.35Se3
PublicationWhile exploring novel magnetic semiconductors, the new phase Cr0.65Al1.35Se3 was discovered and characterized by both structural and physical properties. Cr0.65Al1.35Se3 was found to crystallize into orthorhombic CrGeTe3-type structure with space group Pnma (no. 62). Vacancies and mixed occupancies were tested, and the results show that one of the 4c sites accommodates a mixture of Cr and Al atoms, while the other 4c site is fully...
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Investigation of the Effect of the Rocket's Suborbital Flight on Biofilm, Enzymes and Biosynthesis on Autonomous, Modular and Scalable Platforms For Conducting Experiments of an Astrobiotechnological Nature
PublicationWith new incentives for human space exploration, biotechnological experiments in orbit became imperative. Answering this need, we build an autonomous, modular, and scalable platform that enables those experiments on rockets. We called it AMBER. The aim of the payload of the R6 suborbital rocket is to perform an experiment to study the influence of rocket flights on biofilm, molecular biology enzymes and biosynthesis using our platform....
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Projektowanie poszerzeń międzytorzy w aspekcie zmian dopuszczalnych wartości parametrów geometrycznych i kinematycznych
PublicationW latach 2014–2015 w Polsce wprowadzono długo oczekiwane nowelizacje warunków technicznych, jakim powinny odpowiadać budowle kolejowe i ich usytuowanie (zawartych w Dzienniku Ustaw nr 151 poz. 987 z 1998 r.) oraz Warunków technicznych Id-1. Wprowadziły one istotne zmiany w dopuszczalnych wartościach parametrów geometrycznych i kinematycznych, mających bezpośredni wpływ na projektowanie geometrii toru kolejowego. Z uwagi na duże...
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Wpływ zmian dopuszczalnych wartości parametrów geometrycznych i kinematycznych na podatność modernizacyjną układów torowych
PublicationPodatnością modernizacyjną nazywamy stopień przystosowania analizowanego odcinka linii kolejowej do zmiany prędkości eksploatacyjnej. Skala możliwych zmian prędkości (w sensie jej zwiększenia) jest wypadkową istniejącego układu geometrycznego linii w planie, ograniczeń lokalizacyjnych oraz dopuszczalnych wartości parametrów geometrycznych i kinematycznych. Jakiekolwiek zmiany tych ostatnich wpływają bezpośrednio na obliczenie elementarnych...